diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 1997-01-07 02:33:00 +0000 |
|---|---|---|
| committer | <ralf@linux-mips.org> | 1997-01-07 02:33:00 +0000 |
| commit | beb116954b9b7f3bb56412b2494b562f02b864b1 (patch) | |
| tree | 120e997879884e1b9d93b265221b939d2ef1ade1 /drivers/block/ide-tape.c | |
| parent | 908d4681a1dc3792ecafbe64265783a86c4cccb6 (diff) | |
Import of Linux/MIPS 2.1.14
Diffstat (limited to 'drivers/block/ide-tape.c')
| -rw-r--r-- | drivers/block/ide-tape.c | 3786 |
1 files changed, 3786 insertions, 0 deletions
diff --git a/drivers/block/ide-tape.c b/drivers/block/ide-tape.c new file mode 100644 index 000000000..244072d91 --- /dev/null +++ b/drivers/block/ide-tape.c @@ -0,0 +1,3786 @@ +/* + * linux/drivers/block/ide-tape.c Version 1.10 - BETA Nov 5, 1996 + * + * Copyright (C) 1995, 1996 Gadi Oxman <gadio@netvision.net.il> + * + * This driver was constructed as a student project in the software laboratory + * of the faculty of electrical engineering in the Technion - Israel's + * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David. + * + * It is hereby placed under the terms of the GNU general public license. + * (See linux/COPYING). + */ + +/* + * IDE ATAPI streaming tape driver. + * + * This driver is a part of the Linux ide driver and works in co-operation + * with linux/drivers/block/ide.c. + * + * The driver, in co-operation with ide.c, basically traverses the + * request-list for the block device interface. The character device + * interface, on the other hand, creates new requests, adds them + * to the request-list of the block device, and waits for their completion. + * + * Pipelined operation mode is now supported on both reads and writes. + * + * The block device major and minor numbers are determined from the + * tape's relative position in the ide interfaces, as explained in ide.c. + * + * The character device interface consists of the following devices: + * + * ht0 major 37, minor 0 first IDE tape, rewind on close. + * ht1 major 37, minor 1 second IDE tape, rewind on close. + * ... + * nht0 major 37, minor 128 first IDE tape, no rewind on close. + * nht1 major 37, minor 129 second IDE tape, no rewind on close. + * ... + * + * Run linux/scripts/MAKEDEV.ide to create the above entries. + * + * The general magnetic tape commands compatible interface, as defined by + * include/linux/mtio.h, is accessible through the character device. + * + * General ide driver configuration options, such as the interrupt-unmask + * flag, can be configured by issuing an ioctl to the block device interface, + * as any other ide device. + * + * Our own ide-tape ioctl's can can be issued to either the block device or + * the character device interface. + * + * Maximal throughput with minimal bus load will usually be achieved in the + * following scenario: + * + * 1. ide-tape is operating in the pipelined operation mode. + * 2. No buffering is performed by the user backup program. + * + * Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive. + * + * Ver 0.1 Nov 1 95 Pre-working code :-) + * Ver 0.2 Nov 23 95 A short backup (few megabytes) and restore procedure + * was successful ! (Using tar cvf ... on the block + * device interface). + * A longer backup resulted in major swapping, bad + * overall Linux performance and eventually failed as + * we received non serial read-ahead requests from the + * buffer cache. + * Ver 0.3 Nov 28 95 Long backups are now possible, thanks to the + * character device interface. Linux's responsiveness + * and performance doesn't seem to be much affected + * from the background backup procedure. + * Some general mtio.h magnetic tape operations are + * now supported by our character device. As a result, + * popular tape utilities are starting to work with + * ide tapes :-) + * The following configurations were tested: + * 1. An IDE ATAPI TAPE shares the same interface + * and irq with an IDE ATAPI CDROM. + * 2. An IDE ATAPI TAPE shares the same interface + * and irq with a normal IDE disk. + * Both configurations seemed to work just fine ! + * However, to be on the safe side, it is meanwhile + * recommended to give the IDE TAPE its own interface + * and irq. + * The one thing which needs to be done here is to + * add a "request postpone" feature to ide.c, + * so that we won't have to wait for the tape to finish + * performing a long media access (DSC) request (such + * as a rewind) before we can access the other device + * on the same interface. This effect doesn't disturb + * normal operation most of the time because read/write + * requests are relatively fast, and once we are + * performing one tape r/w request, a lot of requests + * from the other device can be queued and ide.c will + * service all of them after this single tape request. + * Ver 1.0 Dec 11 95 Integrated into Linux 1.3.46 development tree. + * On each read / write request, we now ask the drive + * if we can transfer a constant number of bytes + * (a parameter of the drive) only to its buffers, + * without causing actual media access. If we can't, + * we just wait until we can by polling the DSC bit. + * This ensures that while we are not transferring + * more bytes than the constant referred to above, the + * interrupt latency will not become too high and + * we won't cause an interrupt timeout, as happened + * occasionally in the previous version. + * While polling for DSC, the current request is + * postponed and ide.c is free to handle requests from + * the other device. This is handled transparently to + * ide.c. The hwgroup locking method which was used + * in the previous version was removed. + * Use of new general features which are provided by + * ide.c for use with atapi devices. + * (Programming done by Mark Lord) + * Few potential bug fixes (Again, suggested by Mark) + * Single character device data transfers are now + * not limited in size, as they were before. + * We are asking the tape about its recommended + * transfer unit and send a larger data transfer + * as several transfers of the above size. + * For best results, use an integral number of this + * basic unit (which is shown during driver + * initialization). I will soon add an ioctl to get + * this important parameter. + * Our data transfer buffer is allocated on startup, + * rather than before each data transfer. This should + * ensure that we will indeed have a data buffer. + * Ver 1.1 Dec 14 95 Fixed random problems which occurred when the tape + * shared an interface with another device. + * (poll_for_dsc was a complete mess). + * Removed some old (non-active) code which had + * to do with supporting buffer cache originated + * requests. + * The block device interface can now be opened, so + * that general ide driver features like the unmask + * interrupts flag can be selected with an ioctl. + * This is the only use of the block device interface. + * New fast pipelined operation mode (currently only on + * writes). When using the pipelined mode, the + * throughput can potentially reach the maximum + * tape supported throughput, regardless of the + * user backup program. On my tape drive, it sometimes + * boosted performance by a factor of 2. Pipelined + * mode is enabled by default, but since it has a few + * downfalls as well, you may want to disable it. + * A short explanation of the pipelined operation mode + * is available below. + * Ver 1.2 Jan 1 96 Eliminated pipelined mode race condition. + * Added pipeline read mode. As a result, restores + * are now as fast as backups. + * Optimized shared interface behavior. The new behavior + * typically results in better IDE bus efficiency and + * higher tape throughput. + * Pre-calculation of the expected read/write request + * service time, based on the tape's parameters. In + * the pipelined operation mode, this allows us to + * adjust our polling frequency to a much lower value, + * and thus to dramatically reduce our load on Linux, + * without any decrease in performance. + * Implemented additional mtio.h operations. + * The recommended user block size is returned by + * the MTIOCGET ioctl. + * Additional minor changes. + * Ver 1.3 Feb 9 96 Fixed pipelined read mode bug which prevented the + * use of some block sizes during a restore procedure. + * The character device interface will now present a + * continuous view of the media - any mix of block sizes + * during a backup/restore procedure is supported. The + * driver will buffer the requests internally and + * convert them to the tape's recommended transfer + * unit, making performance almost independent of the + * chosen user block size. + * Some improvements in error recovery. + * By cooperating with triton.c, bus mastering DMA can + * now sometimes be used with IDE tape drives as well. + * Bus mastering DMA has the potential to dramatically + * reduce the CPU's overhead when accessing the device, + * and can be enabled by using hdparm -d1 on the tape's + * block device interface. For more info, read the + * comments in triton.c. + * Ver 1.4 Mar 13 96 Fixed serialize support. + * Ver 1.5 Apr 12 96 Fixed shared interface operation, broken in 1.3.85. + * Fixed pipelined read mode inefficiency. + * Fixed nasty null dereferencing bug. + * Ver 1.6 Aug 16 96 Fixed FPU usage in the driver. + * Fixed end of media bug. + * Ver 1.7 Sep 10 96 Minor changes for the CONNER CTT8000-A model. + * Ver 1.8 Sep 26 96 Attempt to find a better balance between good + * interactive response and high system throughput. + * Ver 1.9 Nov 5 96 Automatically cross encountered filemarks rather + * than requiring an explicit FSF command. + * Abort pending requests at end of media. + * MTTELL was sometimes returning incorrect results. + * Return the real block size in the MTIOCGET ioctl. + * Some error recovery bug fixes. + * Ver 1.10 Nov 5 96 Major reorganization. + * Reduced CPU overhead a bit by eliminating internal + * bounce buffers. + * Added module support. + * Added multiple tape drives support. + * Added partition support. + * Rewrote DSC handling. + * Some portability fixes. + * Removed ide-tape.h. + * Additional minor changes. + * + * Here are some words from the first releases of hd.c, which are quoted + * in ide.c and apply here as well: + * + * | Special care is recommended. Have Fun! + * + */ + +/* + * An overview of the pipelined operation mode. + * + * In the pipelined write mode, we will usually just add requests to our + * pipeline and return immediately, before we even start to service them. The + * user program will then have enough time to prepare the next request while + * we are still busy servicing previous requests. In the pipelined read mode, + * the situation is similar - we add read-ahead requests into the pipeline, + * before the user even requested them. + * + * The pipeline can be viewed as a "safety net" which will be activated when + * the system load is high and prevents the user backup program from keeping up + * with the current tape speed. At this point, the pipeline will get + * shorter and shorter but the tape will still be streaming at the same speed. + * Assuming we have enough pipeline stages, the system load will hopefully + * decrease before the pipeline is completely empty, and the backup program + * will be able to "catch up" and refill the pipeline again. + * + * When using the pipelined mode, it would be best to disable any type of + * buffering done by the user program, as ide-tape already provides all the + * benefits in the kernel, where it can be done in a more efficient way. + * As we will usually not block the user program on a request, the most + * efficient user code will then be a simple read-write-read-... cycle. + * Any additional logic will usually just slow down the backup process. + * + * Using the pipelined mode, I get a constant over 400 KBps throughput, + * which seems to be the maximum throughput supported by my tape. + * + * However, there are some downfalls: + * + * 1. We use memory (for data buffers) in proportional to the number + * of pipeline stages (each stage is about 26 KB with my tape). + * 2. In the pipelined write mode, we cheat and postpone error codes + * to the user task. In read mode, the actual tape position + * will be a bit further than the last requested block. + * + * Concerning (1): + * + * 1. We allocate stages dynamically only when we need them. When + * we don't need them, we don't consume additional memory. In + * case we can't allocate stages, we just manage without them + * (at the expense of decreased throughput) so when Linux is + * tight in memory, we will not pose additional difficulties. + * + * 2. The maximum number of stages (which is, in fact, the maximum + * amount of memory) which we allocate is limited by the compile + * time parameter IDETAPE_MAX_PIPELINE_STAGES. + * + * 3. The maximum number of stages is a controlled parameter - We + * don't start from the user defined maximum number of stages + * but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we + * will not even allocate this amount of stages if the user + * program can't handle the speed). We then implement a feedback + * loop which checks if the pipeline is empty, and if it is, we + * increase the maximum number of stages as necessary until we + * reach the optimum value which just manages to keep the tape + * busy with with minimum allocated memory or until we reach + * IDETAPE_MAX_PIPELINE_STAGES. + * + * Concerning (2): + * + * In pipelined write mode, ide-tape can not return accurate error codes + * to the user program since we usually just add the request to the + * pipeline without waiting for it to be serviced. In case an error + * occurs, I will report it on the next user request. + * + * In the pipelined read mode, subsequent read requests or forward + * filemark spacing will perform correctly, as we preserve all blocks + * and filemarks which we encountered during our excess read-ahead. + * + * For accurate tape positioning and error reporting, disabling + * pipelined mode might be the best option. + * + * You can enable/disable/tune the pipelined operation mode by adjusting + * the compile time parameters below. + */ + +/* + * Possible improvements. + * + * 1. Support for the ATAPI overlap protocol. + * + * In order to maximize bus throughput, we currently use the DSC + * overlap method which enables ide.c to service requests from the + * other device while the tape is busy executing a command. The + * DSC overlap method involves polling the tape's status register + * for the DSC bit, and servicing the other device while the tape + * isn't ready. + * + * In the current QIC development standard (December 1995), + * it is recommended that new tape drives will *in addition* + * implement the ATAPI overlap protocol, which is used for the + * same purpose - efficient use of the IDE bus, but is interrupt + * driven and thus has much less CPU overhead. + * + * ATAPI overlap is likely to be supported in most new ATAPI + * devices, including new ATAPI cdroms, and thus provides us + * a method by which we can achieve higher throughput when + * sharing a (fast) ATA-2 disk with any (slow) new ATAPI device. + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/major.h> +#include <linux/blkdev.h> +#include <linux/errno.h> +#include <linux/hdreg.h> +#include <linux/genhd.h> +#include <linux/malloc.h> + +#include <asm/byteorder.h> +#include <asm/irq.h> +#include <asm/uaccess.h> +#include <asm/io.h> +#include <asm/unaligned.h> +#include <asm/bitops.h> + +/* + * Main Linux ide driver include file + */ +#include "ide.h" + +/* + * For general magnetic tape device compatibility. + */ +#include <linux/mtio.h> + +/**************************** Tunable parameters *****************************/ + +/* + * Pipelined mode parameters. + * + * We try to use the minimum number of stages which is enough to + * keep the tape constantly streaming. To accomplish that, we implement + * a feedback loop around the maximum number of stages: + * + * We start from MIN maximum stages (we will not even use MIN stages + * if we don't need them), increment it by RATE*(MAX-MIN) + * whenever we sense that the pipeline is empty, until we reach + * the optimum value or until we reach MAX. + * + * Setting the following parameter to 0 will disable the pipelined mode. + */ +#define IDETAPE_MIN_PIPELINE_STAGES 100 +#define IDETAPE_MAX_PIPELINE_STAGES 200 +#define IDETAPE_INCREASE_STAGES_RATE 20 + +/* + * Assuming the tape shares an interface with another device, the default + * behavior is to service our pending pipeline requests as soon as + * possible, but to gracefully postpone them in favor of the other device + * when the tape is busy. This has the potential to maximize our + * throughput and in the same time, to make efficient use of the IDE bus. + * + * Note that when we transfer data to / from the tape, we co-operate with + * the relatively fast tape buffers and the tape will perform the + * actual media access in the background, without blocking the IDE + * bus. This means that as long as the maximum IDE bus throughput is much + * higher than the sum of our maximum throughput and the maximum + * throughput of the other device, we should probably leave the default + * behavior. + * + * However, if it is still desired to give the other device a share even + * in our own (small) bus bandwidth, you can set IDETAPE_LOW_TAPE_PRIORITY + * to 1. This will let the other device finish *all* its pending requests + * before we even check if we can service our next pending request. + */ +#define IDETAPE_LOW_TAPE_PRIORITY 0 + +/* + * The following are used to debug the driver: + * + * Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control. + * Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in + * some places. + * + * Setting them to 0 will restore normal operation mode: + * + * 1. Disable logging normal successful operations. + * 2. Disable self-sanity checks. + * 3. Errors will still be logged, of course. + * + * All the #if DEBUG code will be removed some day, when the driver + * is verified to be stable enough. This will make it much more + * esthetic. + */ +#define IDETAPE_DEBUG_LOG 0 +#define IDETAPE_DEBUG_BUGS 1 + +/* + * After each failed packet command we issue a request sense command + * and retry the packet command IDETAPE_MAX_PC_RETRIES times. + * + * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries. + */ +#define IDETAPE_MAX_PC_RETRIES 3 + +/* + * With each packet command, we allocate a buffer of + * IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet + * commands (Not for READ/WRITE commands). + */ +#define IDETAPE_PC_BUFFER_SIZE 256 + +/* + * In various places in the driver, we need to allocate storage + * for packet commands and requests, which will remain valid while + * we leave the driver to wait for an interrupt or a timeout event. + */ +#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES) + +/* + * DSC polling parameters. + * + * Polling for DSC (a single bit in the status register) is a very + * important function in ide-tape. There are two cases in which we + * poll for DSC: + * + * 1. Before a read/write packet command, to ensure that we + * can transfer data from/to the tape's data buffers, without + * causing an actual media access. In case the tape is not + * ready yet, we take out our request from the device + * request queue, so that ide.c will service requests from + * the other device on the same interface meanwhile. + * + * 2. After the successful initialization of a "media access + * packet command", which is a command which can take a long + * time to complete (it can be several seconds or even an hour). + * + * Again, we postpone our request in the middle to free the bus + * for the other device. The polling frequency here should be + * lower than the read/write frequency since those media access + * commands are slow. We start from a "fast" frequency - + * IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC + * after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a + * lower frequency - IDETAPE_DSC_MA_SLOW (1 minute). + * + * We also set a timeout for the timer, in case something goes wrong. + * The timeout should be longer then the maximum execution time of a + * tape operation. + */ + +/* + * The following parameter is used to select the point in the internal + * tape fifo in which we will start to refill the buffer. Decreasing + * the following parameter will improve the system's latency and + * interactive response, while using a high value might improve sytem + * throughput. + */ +#define IDETAPE_FIFO_THRESHOLD 2 + +/* + * DSC timings. + */ +#define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */ +#define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */ +#define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */ +#define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */ +#define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */ +#define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */ +#define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */ + +/*************************** End of tunable parameters ***********************/ + +typedef enum { + idetape_direction_none, + idetape_direction_read, + idetape_direction_write +} idetape_chrdev_direction_t; + +/* + * Our view of a packet command. + */ +typedef struct idetape_packet_command_s { + u8 c[12]; /* Actual packet bytes */ + int retries; /* On each retry, we increment retries */ + int error; /* Error code */ + int request_transfer; /* Bytes to transfer */ + int actually_transferred; /* Bytes actually transferred */ + int buffer_size; /* Size of our data buffer */ + struct buffer_head *bh; + char *b_data; + int b_count; + byte *buffer; /* Data buffer */ + byte *current_position; /* Pointer into the above buffer */ + void (*callback) (ide_drive_t *); /* Called when this packet command is completed */ + byte pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Temporary buffer */ + unsigned int flags; /* Status/Action bit flags */ +} idetape_pc_t; + +/* + * Packet command flag bits. + */ +#define PC_ABORT 0 /* Set when an error is considered normal - We won't retry */ +#define PC_WAIT_FOR_DSC 1 /* 1 When polling for DSC on a media access command */ +#define PC_DMA_RECOMMENDED 2 /* 1 when we prefer to use DMA if possible */ +#define PC_DMA_IN_PROGRESS 3 /* 1 while DMA in progress */ +#define PC_DMA_ERROR 4 /* 1 when encountered problem during DMA */ +#define PC_WRITING 5 /* Data direction */ + +/* + * Capabilities and Mechanical Status Page + */ +typedef struct { + unsigned page_code :6; /* Page code - Should be 0x2a */ + unsigned reserved1_67 :2; + u8 page_length; /* Page Length - Should be 0x12 */ + u8 reserved2, reserved3; + unsigned ro :1; /* Read Only Mode */ + unsigned reserved4_1234 :4; + unsigned sprev :1; /* Supports SPACE in the reverse direction */ + unsigned reserved4_67 :2; + unsigned reserved5_012 :3; + unsigned efmt :1; /* Supports ERASE command initiated formatting */ + unsigned reserved5_4 :1; + unsigned qfa :1; /* Supports the QFA two partition formats */ + unsigned reserved5_67 :2; + unsigned lock :1; /* Supports locking the volume */ + unsigned locked :1; /* The volume is locked */ + unsigned prevent :1; /* The device defaults in the prevent state after power up */ + unsigned eject :1; /* The device can eject the volume */ + unsigned reserved6_45 :2; /* Reserved */ + unsigned ecc :1; /* Supports error correction */ + unsigned cmprs :1; /* Supports data compression */ + unsigned reserved7_0 :1; + unsigned blk512 :1; /* Supports 512 bytes block size */ + unsigned blk1024 :1; /* Supports 1024 bytes block size */ + unsigned reserved7_3_6 :4; + unsigned slowb :1; /* The device restricts the byte count for PIO */ + /* transfers for slow buffer memory ??? */ + u16 max_speed; /* Maximum speed supported in KBps */ + u8 reserved10, reserved11; + u16 ctl; /* Continuous Transfer Limit in blocks */ + u16 speed; /* Current Speed, in KBps */ + u16 buffer_size; /* Buffer Size, in 512 bytes */ + u8 reserved18, reserved19; +} idetape_capabilities_page_t; + +/* + * A pipeline stage. + */ +typedef struct idetape_stage_s { + struct request rq; /* The corresponding request */ + struct buffer_head *bh; /* The data buffers */ + struct idetape_stage_s *next; /* Pointer to the next stage */ +} idetape_stage_t; + +/* + * Most of our global data which we need to save even as we leave the + * driver due to an interrupt or a timer event is stored in a variable + * of type idetape_tape_t, defined below. + */ +typedef struct { + ide_drive_t *drive; + + /* + * Since a typical character device operation requires more + * than one packet command, we provide here enough memory + * for the maximum of interconnected packet commands. + * The packet commands are stored in the circular array pc_stack. + * pc_stack_index points to the last used entry, and warps around + * to the start when we get to the last array entry. + * + * pc points to the current processed packet command. + * + * failed_pc points to the last failed packet command, or contains + * NULL if we do not need to retry any packet command. This is + * required since an additional packet command is needed before the + * retry, to get detailed information on what went wrong. + */ + idetape_pc_t *pc; /* Current packet command */ + idetape_pc_t *failed_pc; /* Last failed packet command */ + idetape_pc_t pc_stack[IDETAPE_PC_STACK];/* Packet command stack */ + int pc_stack_index; /* Next free packet command storage space */ + struct request rq_stack[IDETAPE_PC_STACK]; + int rq_stack_index; /* We implement a circular array */ + + /* + * DSC polling variables. + * + * While polling for DSC we use postponed_rq to postpone the + * current request so that ide.c will be able to service + * pending requests on the other device. Note that at most + * we will have only one DSC (usually data transfer) request + * in the device request queue. Additional requests can be + * queued in our internal pipeline, but they will be visible + * to ide.c only one at a time. + */ + struct request *postponed_rq; + unsigned long dsc_polling_start; /* The time in which we started polling for DSC */ + struct timer_list dsc_timer; /* Timer used to poll for dsc */ + unsigned long best_dsc_rw_frequency; /* Read/Write dsc polling frequency */ + unsigned long dsc_polling_frequency; /* The current polling frequency */ + unsigned long dsc_timeout; /* Maximum waiting time */ + + /* + * Position information + */ + byte partition; + unsigned int block_address; /* Current block */ + + /* + * Last error information + */ + byte sense_key, asc, ascq; + + /* + * Character device operation + */ + unsigned int minor; + char name[4]; /* device name */ + idetape_chrdev_direction_t chrdev_direction; /* Current character device data transfer direction */ + + /* + * Device information + */ + unsigned short tape_block_size; /* Usually 512 or 1024 bytes */ + int user_bs_factor; + idetape_capabilities_page_t capabilities; /* Copy of the tape's Capabilities and Mechanical Page */ + + /* + * Active data transfer request parameters. + * + * At most, there is only one ide-tape originated data transfer + * request in the device request queue. This allows ide.c to + * easily service requests from the other device when we + * postpone our active request. In the pipelined operation + * mode, we use our internal pipeline structure to hold + * more data requests. + * + * The data buffer size is chosen based on the tape's + * recommendation. + */ + struct request *active_data_request; /* Pointer to the request which is waiting in the device request queue */ + int stage_size; /* Data buffer size (chosen based on the tape's recommendation */ + idetape_stage_t *merge_stage; + int merge_stage_size; + struct buffer_head *bh; + char *b_data; + int b_count; + + /* + * Pipeline parameters. + * + * To accomplish non-pipelined mode, we simply set the following + * variables to zero (or NULL, where appropriate). + */ + int nr_stages; /* Number of currently used stages */ + int nr_pending_stages; /* Number of pending stages */ + int max_stages; /* We will not allocate more than this number of stages */ + idetape_stage_t *first_stage; /* The first stage which will be removed from the pipeline */ + idetape_stage_t *active_stage; /* The currently active stage */ + idetape_stage_t *next_stage; /* Will be serviced after the currently active request */ + idetape_stage_t *last_stage; /* New requests will be added to the pipeline here */ + idetape_stage_t *cache_stage; /* Optional free stage which we can use */ + int pages_per_stage; + int excess_bh_size; /* Wasted space in each stage */ + + unsigned int flags; /* Status/Action flags */ +} idetape_tape_t; + +/* + * Tape flag bits values. + */ +#define IDETAPE_IGNORE_DSC 0 +#define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */ +#define IDETAPE_BUSY 2 /* Device already opened */ +#define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */ +#define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */ +#define IDETAPE_FILEMARK 5 /* Currently on a filemark */ + +/* + * Supported ATAPI tape drives packet commands + */ +#define IDETAPE_TEST_UNIT_READY_CMD 0x00 +#define IDETAPE_REWIND_CMD 0x01 +#define IDETAPE_REQUEST_SENSE_CMD 0x03 +#define IDETAPE_READ_CMD 0x08 +#define IDETAPE_WRITE_CMD 0x0a +#define IDETAPE_WRITE_FILEMARK_CMD 0x10 +#define IDETAPE_SPACE_CMD 0x11 +#define IDETAPE_INQUIRY_CMD 0x12 +#define IDETAPE_ERASE_CMD 0x19 +#define IDETAPE_MODE_SENSE_CMD 0x1a +#define IDETAPE_LOAD_UNLOAD_CMD 0x1b +#define IDETAPE_LOCATE_CMD 0x2b +#define IDETAPE_READ_POSITION_CMD 0x34 + +/* + * Some defines for the SPACE command + */ +#define IDETAPE_SPACE_OVER_FILEMARK 1 +#define IDETAPE_SPACE_TO_EOD 3 + +/* + * Some defines for the LOAD UNLOAD command + */ +#define IDETAPE_LU_LOAD_MASK 1 +#define IDETAPE_LU_RETENSION_MASK 2 +#define IDETAPE_LU_EOT_MASK 4 + +/* + * Special requests for our block device strategy routine. + * + * In order to service a character device command, we add special + * requests to the tail of our block device request queue and wait + * for their completion. + * + */ +#define IDETAPE_FIRST_RQ 90 + +/* + * IDETAPE_PC_RQ is used to queue a packet command in the request queue. + */ +#define IDETAPE_PC_RQ 90 + +/* + * IDETAPE_READ_RQ and IDETAPE_WRITE_RQ are used by our + * character device interface to request read/write operations from + * our block device interface. + */ +#define IDETAPE_READ_RQ 92 +#define IDETAPE_WRITE_RQ 93 +#define IDETAPE_ABORTED_WRITE_RQ 94 + +#define IDETAPE_LAST_RQ 94 + +/* + * A macro which can be used to check if a we support a given + * request command. + */ +#define IDETAPE_RQ_CMD(cmd) ((cmd >= IDETAPE_FIRST_RQ) && (cmd <= IDETAPE_LAST_RQ)) + +/* + * We are now able to postpone an idetape request in the stage + * where it is polling for DSC and service requests from the other + * ide device meanwhile. + */ +#define IDETAPE_RQ_POSTPONED 0x1234 + +/* + * Error codes which are returned in rq->errors to the higher part + * of the driver. + */ +#define IDETAPE_ERROR_GENERAL 101 +#define IDETAPE_ERROR_FILEMARK 102 +#define IDETAPE_ERROR_EOD 103 + +/* + * The ATAPI Status Register. + */ +typedef union { + unsigned all :8; + struct { + unsigned check :1; /* Error occurred */ + unsigned idx :1; /* Reserved */ + unsigned corr :1; /* Correctable error occurred */ + unsigned drq :1; /* Data is request by the device */ + unsigned dsc :1; /* Buffer availability / Media access command finished */ + unsigned reserved5 :1; /* Reserved */ + unsigned drdy :1; /* Ignored for ATAPI commands (ready to accept ATA command) */ + unsigned bsy :1; /* The device has access to the command block */ + } b; +} idetape_status_reg_t; + +/* + * The ATAPI error register. + */ +typedef union { + unsigned all :8; + struct { + unsigned ili :1; /* Illegal Length Indication */ + unsigned eom :1; /* End Of Media Detected */ + unsigned abrt :1; /* Aborted command - As defined by ATA */ + unsigned mcr :1; /* Media Change Requested - As defined by ATA */ + unsigned sense_key :4; /* Sense key of the last failed packet command */ + } b; +} idetape_error_reg_t; + +/* + * ATAPI Feature Register + */ +typedef union { + unsigned all :8; + struct { + unsigned dma :1; /* Using DMA of PIO */ + unsigned reserved321 :3; /* Reserved */ + unsigned reserved654 :3; /* Reserved (Tag Type) */ + unsigned reserved7 :1; /* Reserved */ + } b; +} idetape_feature_reg_t; + +/* + * ATAPI Byte Count Register. + */ +typedef union { + unsigned all :16; + struct { + unsigned low :8; /* LSB */ + unsigned high :8; /* MSB */ + } b; +} idetape_bcount_reg_t; + +/* + * ATAPI Interrupt Reason Register. + */ +typedef union { + unsigned all :8; + struct { + unsigned cod :1; /* Information transferred is command (1) or data (0) */ + unsigned io :1; /* The device requests us to read (1) or write (0) */ + unsigned reserved :6; /* Reserved */ + } b; +} idetape_ireason_reg_t; + +/* + * ATAPI Drive Select Register + */ +typedef union { + unsigned all :8; + struct { + unsigned sam_lun :4; /* Should be zero with ATAPI (not used) */ + unsigned drv :1; /* The responding drive will be drive 0 (0) or drive 1 (1) */ + unsigned one5 :1; /* Should be set to 1 */ + unsigned reserved6 :1; /* Reserved */ + unsigned one7 :1; /* Should be set to 1 */ + } b; +} idetape_drivesel_reg_t; + +/* + * ATAPI Device Control Register + */ +typedef union { + unsigned all :8; + struct { + unsigned zero0 :1; /* Should be set to zero */ + unsigned nien :1; /* Device interrupt is disabled (1) or enabled (0) */ + unsigned srst :1; /* ATA software reset. ATAPI devices should use the new ATAPI srst. */ + unsigned one3 :1; /* Should be set to 1 */ + unsigned reserved4567 :4; /* Reserved */ + } b; +} idetape_control_reg_t; + +/* + * idetape_chrdev_t provides the link between out character device + * interface and our block device interface and the corresponding + * ide_drive_t structure. + */ +typedef struct { + ide_drive_t *drive; +} idetape_chrdev_t; + +/* + * The following is used to format the general configuration word of + * the ATAPI IDENTIFY DEVICE command. + */ +struct idetape_id_gcw { + unsigned packet_size :2; /* Packet Size */ + unsigned reserved234 :3; /* Reserved */ + unsigned drq_type :2; /* Command packet DRQ type */ + unsigned removable :1; /* Removable media */ + unsigned device_type :5; /* Device type */ + unsigned reserved13 :1; /* Reserved */ + unsigned protocol :2; /* Protocol type */ +}; + +/* + * INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C) + */ +typedef struct { + unsigned device_type :5; /* Peripheral Device Type */ + unsigned reserved0_765 :3; /* Peripheral Qualifier - Reserved */ + unsigned reserved1_6t0 :7; /* Reserved */ + unsigned rmb :1; /* Removable Medium Bit */ + unsigned ansi_version :3; /* ANSI Version */ + unsigned ecma_version :3; /* ECMA Version */ + unsigned iso_version :2; /* ISO Version */ + unsigned response_format :4; /* Response Data Format */ + unsigned reserved3_45 :2; /* Reserved */ + unsigned reserved3_6 :1; /* TrmIOP - Reserved */ + unsigned reserved3_7 :1; /* AENC - Reserved */ + u8 additional_length; /* Additional Length (total_length-4) */ + u8 rsv5, rsv6, rsv7; /* Reserved */ + u8 vendor_id[8]; /* Vendor Identification */ + u8 product_id[16]; /* Product Identification */ + u8 revision_level[4]; /* Revision Level */ + u8 vendor_specific[20]; /* Vendor Specific - Optional */ + u8 reserved56t95[40]; /* Reserved - Optional */ + /* Additional information may be returned */ +} idetape_inquiry_result_t; + +/* + * READ POSITION packet command - Data Format (From Table 6-57) + */ +typedef struct { + unsigned reserved0_10 :2; /* Reserved */ + unsigned bpu :1; /* Block Position Unknown */ + unsigned reserved0_543 :3; /* Reserved */ + unsigned eop :1; /* End Of Partition */ + unsigned bop :1; /* Beginning Of Partition */ + u8 partition; /* Partition Number */ + u8 reserved2, reserved3; /* Reserved */ + u32 first_block; /* First Block Location */ + u32 last_block; /* Last Block Location (Optional) */ + u8 reserved12; /* Reserved */ + u8 blocks_in_buffer[3]; /* Blocks In Buffer - (Optional) */ + u32 bytes_in_buffer; /* Bytes In Buffer (Optional) */ +} idetape_read_position_result_t; + +/* + * REQUEST SENSE packet command result - Data Format. + */ +typedef struct { + unsigned error_code :7; /* Current of deferred errors */ + unsigned valid :1; /* The information field conforms to QIC-157C */ + u8 reserved1 :8; /* Segment Number - Reserved */ + unsigned sense_key :4; /* Sense Key */ + unsigned reserved2_4 :1; /* Reserved */ + unsigned ili :1; /* Incorrect Length Indicator */ + unsigned eom :1; /* End Of Medium */ + unsigned filemark :1; /* Filemark */ + u32 information __attribute__ ((packed)); + u8 asl; /* Additional sense length (n-7) */ + u32 command_specific; /* Additional command specific information */ + u8 asc; /* Additional Sense Code */ + u8 ascq; /* Additional Sense Code Qualifier */ + u8 replaceable_unit_code; /* Field Replaceable Unit Code */ + unsigned sk_specific1 :7; /* Sense Key Specific */ + unsigned sksv :1; /* Sense Key Specific information is valid */ + u8 sk_specific2; /* Sense Key Specific */ + u8 sk_specific3; /* Sense Key Specific */ + u8 pad[2]; /* Padding to 20 bytes */ +} idetape_request_sense_result_t; + +/* + * Follows structures which are related to the SELECT SENSE / MODE SENSE + * packet commands. Those packet commands are still not supported + * by ide-tape. + */ +#define IDETAPE_CAPABILITIES_PAGE 0x2a + +/* + * Mode Parameter Header for the MODE SENSE packet command + */ +typedef struct { + u8 mode_data_length; /* Length of the following data transfer */ + u8 medium_type; /* Medium Type */ + u8 dsp; /* Device Specific Parameter */ + u8 bdl; /* Block Descriptor Length */ +} idetape_mode_parameter_header_t; + +/* + * Mode Parameter Block Descriptor the MODE SENSE packet command + * + * Support for block descriptors is optional. + */ +typedef struct { + u8 density_code; /* Medium density code */ + u8 blocks[3]; /* Number of blocks */ + u8 reserved4; /* Reserved */ + u8 length[3]; /* Block Length */ +} idetape_parameter_block_descriptor_t; + +/* + * The Data Compression Page, as returned by the MODE SENSE packet command. + */ +typedef struct { + unsigned page_code :6; /* Page Code - Should be 0xf */ + unsigned reserved0 :1; /* Reserved */ + unsigned ps :1; + u8 page_length; /* Page Length - Should be 14 */ + unsigned reserved2 :6; /* Reserved */ + unsigned dcc :1; /* Data Compression Capable */ + unsigned dce :1; /* Data Compression Enable */ + unsigned reserved3 :5; /* Reserved */ + unsigned red :2; /* Report Exception on Decompression */ + unsigned dde :1; /* Data Decompression Enable */ + u32 ca; /* Compression Algorithm */ + u32 da; /* Decompression Algorithm */ + u8 reserved[4]; /* Reserved */ +} idetape_data_compression_page_t; + +/* + * The Medium Partition Page, as returned by the MODE SENSE packet command. + */ +typedef struct { + unsigned page_code :6; /* Page Code - Should be 0x11 */ + unsigned reserved1_6 :1; /* Reserved */ + unsigned ps :1; + u8 page_length; /* Page Length - Should be 6 */ + u8 map; /* Maximum Additional Partitions - Should be 0 */ + u8 apd; /* Additional Partitions Defined - Should be 0 */ + unsigned reserved4_012 :3; /* Reserved */ + unsigned psum :2; /* Should be 0 */ + unsigned idp :1; /* Should be 0 */ + unsigned sdp :1; /* Should be 0 */ + unsigned fdp :1; /* Fixed Data Partitions */ + u8 mfr; /* Medium Format Recognition */ + u8 reserved[2]; /* Reserved */ +} idetape_medium_partition_page_t; + +#define IDETAPE_MIN(a,b) ((a)<(b) ? (a):(b)) +#define IDETAPE_MAX(a,b) ((a)>(b) ? (a):(b)) + +/* + * Run time configurable parameters. + */ +typedef struct { + int dsc_rw_frequency; + int dsc_media_access_frequency; + int nr_stages; +} idetape_config_t; + +/* + * The variables below are used for the character device interface. + * Additional state variables are defined in our ide_drive_t structure. + */ +static idetape_chrdev_t idetape_chrdevs[MAX_HWIFS * MAX_DRIVES]; +static int idetape_chrdev_present = 0; + +/* + * Too bad. The drive wants to send us data which we are not ready to accept. + * Just throw it away. + */ +static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount) +{ + while (bcount--) + IN_BYTE (IDE_DATA_REG); +} + +static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount) +{ + struct buffer_head *bh = pc->bh; + int count; + + while (bcount) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk (KERN_ERR "ide-tape: bh == NULL in idetape_input_buffers\n"); + idetape_discard_data (drive, bcount); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = IDETAPE_MIN (bh->b_size - bh->b_count, bcount); + atapi_input_bytes (drive, bh->b_data + bh->b_count, count); + bcount -= count; bh->b_count += count; + if (bh->b_count == bh->b_size) { + bh = bh->b_reqnext; + if (bh) + bh->b_count = 0; + } + } + pc->bh = bh; +} + +static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount) +{ + struct buffer_head *bh = pc->bh; + int count; + + while (bcount) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk (KERN_ERR "ide-tape: bh == NULL in idetape_output_buffers\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = IDETAPE_MIN (pc->b_count, bcount); + atapi_output_bytes (drive, pc->b_data, count); + bcount -= count; pc->b_data += count; pc->b_count -= count; + if (!pc->b_count) { + pc->bh = bh = bh->b_reqnext; + if (bh) { + pc->b_data = bh->b_data; + pc->b_count = bh->b_count; + } + } + } +} + +#ifdef CONFIG_BLK_DEV_TRITON +static void idetape_update_buffers (idetape_pc_t *pc) +{ + struct buffer_head *bh = pc->bh; + int count, bcount = pc->actually_transferred; + + if (test_bit (PC_WRITING, &pc->flags)) + return; + while (bcount) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk (KERN_ERR "ide-tape: bh == NULL in idetape_update_buffers\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = IDETAPE_MIN (bh->b_size, bcount); + bh->b_count = count; + if (bh->b_count == bh->b_size) + bh = bh->b_reqnext; + bcount -= count; + } + pc->bh = bh; +} +#endif /* CONFIG_BLK_DEV_TRITON */ + +/* + * idetape_poll_for_dsc gets invoked by a timer (which was set + * by idetape_postpone_request) to reinsert our postponed request + * into the request queue. + * + * Note that the procedure done here is different than the method + * we are using in idetape_queue_pc_head - There we are putting + * request(s) before our currently called request. + * + * Here, on the other hand, HWGROUP(drive)->rq is not our request + * but rather a request to another device. Therefore, we will let + * it finish and only then service our postponed request --> We don't + * touch HWGROUP(drive)->rq. + */ +static void idetape_poll_for_dsc (unsigned long data) +{ + ide_drive_t *drive=(ide_drive_t *) data; + idetape_tape_t *tape = drive->driver_data; + + del_timer (&tape->dsc_timer); + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Putting back postponed request\n"); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (tape->postponed_rq == NULL) { + printk (KERN_ERR "tape->postponed_rq is NULL in idetape_poll_for_dsc\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + + (void) ide_do_drive_cmd (drive, tape->postponed_rq, ide_next); +} + +/* + * idetape_postpone_request postpones the current request so that + * ide.c will be able to service requests from another device on + * the same hwgroup while we are polling for DSC. + */ +static void idetape_postpone_request (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + struct request *rq; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_postpone_request\n"); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (tape->postponed_rq != NULL) + printk (KERN_ERR "ide-tape.c bug - postponed_rq not NULL in idetape_postpone_request\n"); +#endif /* IDETAPE_DEBUG_BUGS */ + + /* + * Set the timer parameters. + */ + tape->dsc_timer.expires=jiffies + tape->dsc_polling_frequency; + tape->dsc_timer.data=(unsigned long) drive; + tape->dsc_timer.function = &idetape_poll_for_dsc; + init_timer (&tape->dsc_timer); + + /* + * Remove current request from the request queue: + */ + tape->postponed_rq = rq = HWGROUP(drive)->rq; + rq->rq_status = IDETAPE_RQ_POSTPONED; + blk_dev[MAJOR(rq->rq_dev)].current_request = rq->next; + HWGROUP(drive)->rq = NULL; + + add_timer(&tape->dsc_timer); /* Activate the polling timer */ +} + +/* + * idetape_queue_pc_head generates a new packet command request in front + * of the request queue, before the current request, so that it will be + * processed immediately, on the next pass through the driver. + * + * idetape_queue_pc_head is called from the request handling part of + * the driver (the "bottom" part). Safe storage for the request should + * be allocated with idetape_next_pc_storage and idetape_next_rq_storage + * before calling idetape_queue_pc_head. + * + * Memory for those requests is pre-allocated at initialization time, and + * is limited to IDETAPE_PC_STACK requests. We assume that we have enough + * space for the maximum possible number of inter-dependent packet commands. + * + * The higher level of the driver - The ioctl handler and the character + * device handling functions should queue request to the lower level part + * and wait for their completion using idetape_queue_pc_tail or + * idetape_queue_rw_tail. + */ +static void idetape_queue_pc_head (ide_drive_t *drive,idetape_pc_t *pc,struct request *rq) +{ + unsigned int major = HWIF(drive)->major; + struct blk_dev_struct *bdev = &blk_dev[major]; + + bdev->current_request=HWGROUP (drive)->rq; /* Since we may have taken it out */ + + ide_init_drive_cmd (rq); + rq->buffer = (char *) pc; + rq->cmd = IDETAPE_PC_RQ; + (void) ide_do_drive_cmd (drive, rq, ide_preempt); +} + +/* + * idetape_next_pc_storage returns a pointer to a place in which we can + * safely store a packet command, even though we intend to leave the + * driver. A storage space for a maximum of IDETAPE_PC_STACK packet + * commands is allocated at initialization time. + */ +static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: pc_stack_index=%d\n",tape->pc_stack_index); +#endif /* IDETAPE_DEBUG_LOG */ + if (tape->pc_stack_index==IDETAPE_PC_STACK) + tape->pc_stack_index=0; + return (&tape->pc_stack[tape->pc_stack_index++]); +} + +/* + * idetape_next_rq_storage is used along with idetape_next_pc_storage. + * Since we queue packet commands in the request queue, we need to + * allocate a request, along with the allocation of a packet command. + */ + +/************************************************************** + * * + * This should get fixed to use kmalloc(GFP_ATOMIC, ..) * + * followed later on by kfree(). -ml * + * * + **************************************************************/ + +static struct request *idetape_next_rq_storage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: rq_stack_index=%d\n",tape->rq_stack_index); +#endif /* IDETAPE_DEBUG_LOG */ + if (tape->rq_stack_index==IDETAPE_PC_STACK) + tape->rq_stack_index=0; + return (&tape->rq_stack[tape->rq_stack_index++]); +} + +/* + * Pipeline related functions + */ + +static inline int idetape_pipeline_active (idetape_tape_t *tape) +{ + return tape->active_data_request != NULL; +} + +/* + * idetape_kfree_stage calls kfree to completely free a stage, along with + * its related buffers. + */ +static void __idetape_kfree_stage (idetape_stage_t *stage) +{ + struct buffer_head *prev_bh, *bh = stage->bh; + int size; + + while (bh != NULL) { + if (bh->b_data != NULL) { + size = (int) bh->b_size; + while (size > 0) { + free_page ((unsigned long) bh->b_data); + size -= PAGE_SIZE; + bh->b_data += PAGE_SIZE; + } + } + prev_bh = bh; + bh = bh->b_reqnext; + kfree (prev_bh); + } + kfree (stage); +} + +static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage) +{ + if (tape->cache_stage == NULL) + tape->cache_stage = stage; + else + __idetape_kfree_stage (stage); +} + +/* + * idetape_kmalloc_stage uses __get_free_page to allocate a pipeline + * stage, along with all the necessary small buffers which together make + * a buffer of size tape->stage_size (or a bit more). We attempt to + * combine sequential pages as much as possible. + * + * Returns a pointer to the new allocated stage, or NULL if we + * can't (or don't want to) allocate a stage. + * + * Pipeline stages are optional and are used to increase performance. + * If we can't allocate them, we'll manage without them. + */ +static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape) +{ + idetape_stage_t *stage; + struct buffer_head *prev_bh, *bh; + int pages = tape->pages_per_stage; + char *b_data; + + if ((stage = (idetape_stage_t *) kmalloc (sizeof (idetape_stage_t),GFP_KERNEL)) == NULL) + return NULL; + stage->next = NULL; + + bh = stage->bh = (struct buffer_head *) kmalloc (sizeof (struct buffer_head), GFP_KERNEL); + if (bh == NULL) + goto abort; + bh->b_reqnext = NULL; + if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL) + goto abort; + bh->b_size = PAGE_SIZE; + set_bit (BH_Lock, &bh->b_state); + + while (--pages) { + if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL) + goto abort; + if (bh->b_data == b_data + PAGE_SIZE && virt_to_bus (bh->b_data) == virt_to_bus (b_data) + PAGE_SIZE) { + bh->b_size += PAGE_SIZE; + bh->b_data -= PAGE_SIZE; + continue; + } + if (b_data == bh->b_data + bh->b_size && virt_to_bus (b_data) == virt_to_bus (bh->b_data) + bh->b_size) { + bh->b_size += PAGE_SIZE; + continue; + } + prev_bh = bh; + if ((bh = (struct buffer_head *) kmalloc (sizeof (struct buffer_head), GFP_KERNEL)) == NULL) { + free_page ((unsigned long) b_data); + goto abort; + } + bh->b_reqnext = NULL; + bh->b_data = b_data; + bh->b_size = PAGE_SIZE; + set_bit (BH_Lock, &bh->b_state); + prev_bh->b_reqnext = bh; + } + bh->b_size -= tape->excess_bh_size; + return stage; +abort: + __idetape_kfree_stage (stage); + return NULL; +} + +static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape) +{ + idetape_stage_t *cache_stage = tape->cache_stage; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_kmalloc_stage\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->nr_stages >= tape->max_stages) + return NULL; + if (cache_stage != NULL) { + tape->cache_stage = NULL; + return cache_stage; + } + return __idetape_kmalloc_stage (tape); +} + +static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char *buf, int n) +{ + struct buffer_head *bh = tape->bh; + int count; + + while (n) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk (KERN_ERR "ide-tape: bh == NULL in idetape_copy_stage_from_user\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = IDETAPE_MIN (bh->b_size - bh->b_count, n); + copy_from_user (bh->b_data + bh->b_count, buf, count); + n -= count; bh->b_count += count; buf += count; + if (bh->b_count == bh->b_size) { + bh = bh->b_reqnext; + if (bh) + bh->b_count = 0; + } + } + tape->bh = bh; +} + +static void idetape_copy_stage_to_user (idetape_tape_t *tape, char *buf, idetape_stage_t *stage, int n) +{ + struct buffer_head *bh = tape->bh; + int count; + + while (n) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk (KERN_ERR "ide-tape: bh == NULL in idetape_copy_stage_to_user\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = IDETAPE_MIN (tape->b_count, n); + copy_to_user (buf, tape->b_data, count); + n -= count; tape->b_data += count; tape->b_count -= count; buf += count; + if (!tape->b_count) { + tape->bh = bh = bh->b_reqnext; + if (bh) { + tape->b_data = bh->b_data; + tape->b_count = bh->b_count; + } + } + } +} + +static void idetape_init_merge_stage (idetape_tape_t *tape) +{ + struct buffer_head *bh = tape->merge_stage->bh; + + tape->bh = bh; + if (tape->chrdev_direction == idetape_direction_write) + bh->b_count = 0; + else { + tape->b_data = bh->b_data; + tape->b_count = bh->b_count; + } +} + +static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage) +{ + struct buffer_head *tmp; + + tmp = stage->bh; + stage->bh = tape->merge_stage->bh; + tape->merge_stage->bh = tmp; + idetape_init_merge_stage (tape); +} + +/* + * idetape_increase_max_pipeline_stages is a part of the feedback + * loop which tries to find the optimum number of stages. In the + * feedback loop, we are starting from a minimum maximum number of + * stages, and if we sense that the pipeline is empty, we try to + * increase it, until we reach the user compile time memory limit. + */ +static void idetape_increase_max_pipeline_stages (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_increase_max_pipeline_stages\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + tape->max_stages = IDETAPE_MIN (tape->max_stages + IDETAPE_INCREASE_STAGES_RATE, IDETAPE_MAX_PIPELINE_STAGES); +} + +/* + * idetape_add_stage_tail adds a new stage at the end of the pipeline. + */ +static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_add_stage_tail\n"); +#endif /* IDETAPE_DEBUG_LOG */ + save_flags (flags); + cli (); + stage->next=NULL; + if (tape->last_stage != NULL) + tape->last_stage->next=stage; + else + tape->first_stage=tape->next_stage=stage; + tape->last_stage=stage; + if (tape->next_stage == NULL) + tape->next_stage=tape->last_stage; + tape->nr_stages++; + tape->nr_pending_stages++; + restore_flags (flags); +} + +/* + * idetape_remove_stage_head removes tape->first_stage from the pipeline. + * The caller should avoid race conditions. + */ +static void idetape_remove_stage_head (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_remove_stage_head\n"); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (tape->first_stage == NULL) { + printk (KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n"); + return; + } + if (tape->active_stage == tape->first_stage) { + printk (KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + stage=tape->first_stage; + tape->first_stage=stage->next; + idetape_kfree_stage (tape, stage); + tape->nr_stages--; + if (tape->first_stage == NULL) { + tape->last_stage=NULL; +#if IDETAPE_DEBUG_BUGS + if (tape->next_stage != NULL) + printk (KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n"); + if (tape->nr_stages) + printk (KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n"); +#endif /* IDETAPE_DEBUG_BUGS */ + } +} + +/* + * idetape_active_next_stage will declare the next stage as "active". + */ +static void idetape_active_next_stage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage=tape->next_stage; + struct request *rq = &stage->rq; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_active_next_stage\n"); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (stage == NULL) { + printk (KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + + rq->buffer = NULL; + rq->bh = stage->bh; + tape->active_data_request=rq; + tape->active_stage=stage; + tape->next_stage=stage->next; +} + +/* + * idetape_insert_pipeline_into_queue is used to start servicing the + * pipeline stages, starting from tape->next_stage. + */ +static void idetape_insert_pipeline_into_queue (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + + if (tape->next_stage == NULL) + return; + if (!idetape_pipeline_active (tape)) { + idetape_active_next_stage (drive); + (void) ide_do_drive_cmd (drive, tape->active_data_request, ide_end); + } +} + +static void idetape_abort_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage = tape->next_stage; + + while (stage) { + stage->rq.cmd = IDETAPE_ABORTED_WRITE_RQ; + stage = stage->next; + } +} + +/* + * idetape_end_request is used to finish servicing a request, and to + * insert a pending pipeline request into the main device queue. + */ +static void idetape_end_request (byte uptodate, ide_hwgroup_t *hwgroup) +{ + ide_drive_t *drive = hwgroup->drive; + struct request *rq = hwgroup->rq; + idetape_tape_t *tape = drive->driver_data; + unsigned int major = HWIF(drive)->major; + struct blk_dev_struct *bdev = &blk_dev[major]; + int error; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_end_request\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + bdev->current_request=rq; /* Since we may have taken it out */ + + switch (uptodate) { + case 0: error = IDETAPE_ERROR_GENERAL; break; + case 1: error = 0; break; + default: error = uptodate; + } + rq->errors = error; + if (error) + tape->failed_pc = NULL; + + if (tape->active_data_request == rq) { /* The request was a pipelined data transfer request */ + tape->active_stage = NULL; + tape->active_data_request = NULL; + tape->nr_pending_stages--; + if (rq->cmd == IDETAPE_WRITE_RQ) { + if (error) { + set_bit (IDETAPE_PIPELINE_ERROR, &tape->flags); + if (error == IDETAPE_ERROR_EOD) + idetape_abort_pipeline (drive); + } + idetape_remove_stage_head (drive); + } + if (tape->next_stage != NULL) { + idetape_active_next_stage (drive); + + /* + * Insert the next request into the request queue. + * The choice of using ide_next or ide_end is now left to the user. + */ +#if IDETAPE_LOW_TAPE_PRIORITY + (void) ide_do_drive_cmd (drive, tape->active_data_request, ide_end); +#else + (void) ide_do_drive_cmd (drive, tape->active_data_request, ide_next); +#endif /* IDETAPE_LOW_TAPE_PRIORITY */ + } else if (!error) + idetape_increase_max_pipeline_stages (drive); + } + ide_end_drive_cmd (drive, 0, 0); +} + +/* + * idetape_analyze_error is called on each failed packet command retry + * to analyze the request sense. We currently do not utilize this + * information. + */ +static void idetape_analyze_error (ide_drive_t *drive,idetape_request_sense_result_t *result) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc = tape->failed_pc; + + tape->sense_key = result->sense_key; tape->asc = result->asc; tape->ascq = result->ascq; +#if IDETAPE_DEBUG_LOG + /* + * Without debugging, we only log an error if we decided to + * give up retrying. + */ + printk (KERN_INFO "ide-tape: pc = %x, sense key = %x, asc = %x, ascq = %x\n",pc->c[0],result->sense_key,result->asc,result->ascq); +#endif /* IDETAPE_DEBUG_LOG */ + +#ifdef CONFIG_BLK_DEV_TRITON + + /* + * Correct pc->actually_transferred by asking the tape. + */ + if (test_bit (PC_DMA_ERROR, &pc->flags)) { + pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl (get_unaligned (&result->information)); + idetape_update_buffers (pc); + } +#endif /* CONFIG_BLK_DEV_TRITON */ + if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) { + pc->error = IDETAPE_ERROR_FILEMARK; + set_bit (PC_ABORT, &pc->flags); + } + if (pc->c[0] == IDETAPE_WRITE_CMD) { + if (result->eom || (result->sense_key == 0xd && result->asc == 0x0 && result->ascq == 0x2)) { + pc->error = IDETAPE_ERROR_EOD; + set_bit (PC_ABORT, &pc->flags); + } + } + if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) { + if (result->sense_key == 8) { + pc->error = IDETAPE_ERROR_EOD; + set_bit (PC_ABORT, &pc->flags); + } + if (!test_bit (PC_ABORT, &pc->flags) && pc->actually_transferred) + pc->retries = IDETAPE_MAX_PC_RETRIES + 1; + } +} + +static void idetape_request_sense_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + if (!tape->pc->error) { + idetape_analyze_error (drive,(idetape_request_sense_result_t *) tape->pc->buffer); + idetape_end_request (1,HWGROUP (drive)); + } else { + printk (KERN_ERR "Error in REQUEST SENSE itself - Aborting request!\n"); + idetape_end_request (0,HWGROUP (drive)); + } +} + +/* + * idetape_init_pc initializes a packet command. + */ +static void idetape_init_pc (idetape_pc_t *pc) +{ + memset (pc->c, 0, 12); + pc->retries = 0; + pc->flags = 0; + pc->request_transfer = 0; + pc->buffer = pc->pc_buffer; + pc->buffer_size = IDETAPE_PC_BUFFER_SIZE; + pc->bh = NULL; + pc->b_data = NULL; +} + +static void idetape_create_request_sense_cmd (idetape_pc_t *pc) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_REQUEST_SENSE_CMD; + pc->c[4] = 255; + pc->request_transfer = 18; + pc->callback = &idetape_request_sense_callback; +} + +/* + * idetape_retry_pc is called when an error was detected during the + * last packet command. We queue a request sense packet command in + * the head of the request list. + */ +static void idetape_retry_pc (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc; + struct request *rq; + idetape_error_reg_t error; + + error.all = IN_BYTE (IDE_ERROR_REG); + pc = idetape_next_pc_storage (drive); + rq = idetape_next_rq_storage (drive); + idetape_create_request_sense_cmd (pc); + set_bit (IDETAPE_IGNORE_DSC, &tape->flags); + idetape_queue_pc_head (drive, pc, rq); +} + +/* + * idetape_pc_intr is the usual interrupt handler which will be called + * during a packet command. We will transfer some of the data (as + * requested by the drive) and will re-point interrupt handler to us. + * When data transfer is finished, we will act according to the + * algorithm described before idetape_issue_packet_command. + * + */ +static void idetape_pc_intr (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_status_reg_t status; + idetape_bcount_reg_t bcount; + idetape_ireason_reg_t ireason; + idetape_pc_t *pc=tape->pc; + unsigned int temp; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Reached idetape_pc_intr interrupt handler\n"); +#endif /* IDETAPE_DEBUG_LOG */ + +#ifdef CONFIG_BLK_DEV_TRITON + if (test_bit (PC_DMA_IN_PROGRESS, &pc->flags)) { + if (HWIF(drive)->dmaproc(ide_dma_status_bad, drive)) { + set_bit (PC_DMA_ERROR, &pc->flags); + /* + * We will currently correct the following in + * idetape_analyze_error. + */ + pc->actually_transferred=HWIF(drive)->dmaproc(ide_dma_transferred, drive); + } else { + pc->actually_transferred=pc->request_transfer; + idetape_update_buffers (pc); + } + (void) (HWIF(drive)->dmaproc(ide_dma_abort, drive)); /* End DMA */ +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: DMA finished\n"); +#endif /* IDETAPE_DEBUG_LOG */ + } +#endif /* CONFIG_BLK_DEV_TRITON */ + + status.all = GET_STAT(); /* Clear the interrupt */ + + if (!status.b.drq) { /* No more interrupts */ +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Packet command completed, %d bytes transferred\n", pc->actually_transferred); +#endif /* IDETAPE_DEBUG_LOG */ + clear_bit (PC_DMA_IN_PROGRESS, &pc->flags); + + ide_sti(); + + if (status.b.check || test_bit (PC_DMA_ERROR, &pc->flags)) { /* Error detected */ +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: %s: I/O error, ",tape->name); +#endif /* IDETAPE_DEBUG_LOG */ + if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) { + printk (KERN_ERR "ide-tape: I/O error in request sense command\n"); + ide_do_reset (drive); + return; + } + idetape_retry_pc (drive); /* Retry operation */ + return; + } + pc->error = 0; + if (test_bit (PC_WAIT_FOR_DSC, &pc->flags) && !status.b.dsc) { /* Media access command */ + tape->dsc_polling_start = jiffies; + tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST; + tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT; + idetape_postpone_request (drive); /* Allow ide.c to handle other requests */ + return; + } + if (tape->failed_pc == pc) + tape->failed_pc=NULL; + pc->callback(drive); /* Command finished - Call the callback function */ + return; + } +#ifdef CONFIG_BLK_DEV_TRITON + if (clear_bit (PC_DMA_IN_PROGRESS, &pc->flags)) { + printk (KERN_ERR "ide-tape: The tape wants to issue more interrupts in DMA mode\n"); + printk (KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n"); + drive->using_dma=0; + ide_do_reset (drive); + return; + } +#endif /* CONFIG_BLK_DEV_TRITON */ + bcount.b.high=IN_BYTE (IDE_BCOUNTH_REG); /* Get the number of bytes to transfer */ + bcount.b.low=IN_BYTE (IDE_BCOUNTL_REG); /* on this interrupt */ + ireason.all=IN_BYTE (IDE_IREASON_REG); + + if (ireason.b.cod) { + printk (KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n"); + ide_do_reset (drive); + return; + } + if (ireason.b.io == test_bit (PC_WRITING, &pc->flags)) { /* Hopefully, we will never get here */ + printk (KERN_ERR "ide-tape: We wanted to %s, ", ireason.b.io ? "Write":"Read"); + printk (KERN_ERR "but the tape wants us to %s !\n",ireason.b.io ? "Read":"Write"); + ide_do_reset (drive); + return; + } + if (!test_bit (PC_WRITING, &pc->flags)) { /* Reading - Check that we have enough space */ + temp = pc->actually_transferred + bcount.all; + if ( temp > pc->request_transfer) { + if (temp > pc->buffer_size) { + printk (KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n"); + idetape_discard_data (drive,bcount.all); + ide_set_handler (drive,&idetape_pc_intr,WAIT_CMD); + return; + } +#if IDETAPE_DEBUG_LOG + printk (KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n"); +#endif /* IDETAPE_DEBUG_LOG */ + } + } + if (test_bit (PC_WRITING, &pc->flags)) { + if (pc->bh != NULL) + idetape_output_buffers (drive, pc, bcount.all); + else + atapi_output_bytes (drive,pc->current_position,bcount.all); /* Write the current buffer */ + } else { + if (pc->bh != NULL) + idetape_input_buffers (drive, pc, bcount.all); + else + atapi_input_bytes (drive,pc->current_position,bcount.all); /* Read the current buffer */ + } + pc->actually_transferred+=bcount.all; /* Update the current position */ + pc->current_position+=bcount.all; + + ide_set_handler (drive,&idetape_pc_intr,WAIT_CMD); /* And set the interrupt handler again */ +} + +/* + * Packet Command Interface + * + * The current Packet Command is available in tape->pc, and will not + * change until we finish handling it. Each packet command is associated + * with a callback function that will be called when the command is + * finished. + * + * The handling will be done in three stages: + * + * 1. idetape_issue_packet_command will send the packet command to the + * drive, and will set the interrupt handler to idetape_pc_intr. + * + * 2. On each interrupt, idetape_pc_intr will be called. This step + * will be repeated until the device signals us that no more + * interrupts will be issued. + * + * 3. ATAPI Tape media access commands have immediate status with a + * delayed process. In case of a successful initiation of a + * media access packet command, the DSC bit will be set when the + * actual execution of the command is finished. + * Since the tape drive will not issue an interrupt, we have to + * poll for this event. In this case, we define the request as + * "low priority request" by setting rq_status to + * IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and exit + * the driver. + * + * ide.c will then give higher priority to requests which + * originate from the other device, until will change rq_status + * to RQ_ACTIVE. + * + * 4. When the packet command is finished, it will be checked for errors. + * + * 5. In case an error was found, we queue a request sense packet command + * in front of the request queue and retry the operation up to + * IDETAPE_MAX_PC_RETRIES times. + * + * 6. In case no error was found, or we decided to give up and not + * to retry again, the callback function will be called and then + * we will handle the next request. + * + */ +static void idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_bcount_reg_t bcount; + idetape_ireason_reg_t ireason; + int dma_ok=0; + +#if IDETAPE_DEBUG_BUGS + if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) { + printk (KERN_ERR "ide-tape: possible ide-tape.c bug - Two request sense in serial were issued\n"); + } +#endif /* IDETAPE_DEBUG_BUGS */ + + if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD) + tape->failed_pc=pc; + tape->pc=pc; /* Set the current packet command */ + + if (pc->retries > IDETAPE_MAX_PC_RETRIES || test_bit (PC_ABORT, &pc->flags)) { + /* + * We will "abort" retrying a packet command in case + * a legitimate error code was received (crossing a + * filemark, or DMA error in the end of media, for + * example). + */ + if (!test_bit (PC_ABORT, &pc->flags)) { + printk (KERN_ERR "ide-tape: %s: I/O error, pc = %2x, key = %2x, asc = %2x, ascq = %2x\n", + tape->name, pc->c[0], tape->sense_key, tape->asc, tape->ascq); + pc->error = IDETAPE_ERROR_GENERAL; /* Giving up */ + } + tape->failed_pc=NULL; + pc->callback(drive); + return; + } +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Retry number - %d\n",pc->retries); +#endif /* IDETAPE_DEBUG_LOG */ + + pc->retries++; + pc->actually_transferred=0; /* We haven't transferred any data yet */ + pc->current_position=pc->buffer; + bcount.all=pc->request_transfer; /* Request to transfer the entire buffer at once */ + +#ifdef CONFIG_BLK_DEV_TRITON + if (clear_bit (PC_DMA_ERROR, &pc->flags)) { + printk (KERN_WARNING "ide-tape: DMA disabled, reverting to PIO\n"); + drive->using_dma=0; + } + if (test_bit (PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma) + dma_ok=!HWIF(drive)->dmaproc(test_bit (PC_WRITING, &pc->flags) ? ide_dma_write : ide_dma_read, drive); +#endif /* CONFIG_BLK_DEV_TRITON */ + + OUT_BYTE (drive->ctl,IDE_CONTROL_REG); + OUT_BYTE (dma_ok ? 1:0,IDE_FEATURE_REG); /* Use PIO/DMA */ + OUT_BYTE (bcount.b.high,IDE_BCOUNTH_REG); + OUT_BYTE (bcount.b.low,IDE_BCOUNTL_REG); + OUT_BYTE (drive->select.all,IDE_SELECT_REG); + + ide_set_handler (drive, &idetape_pc_intr, WAIT_CMD); /* Set the interrupt routine */ + OUT_BYTE (WIN_PACKETCMD,IDE_COMMAND_REG); /* Issue the packet command */ + + if (ide_wait_stat (drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) { /* Wait for DRQ to be ready - Assuming Accelerated DRQ */ + /* + * We currently only support tape drives which report + * accelerated DRQ assertion. For this case, specs + * allow up to 50us. We really shouldn't get here. + * + * ??? Still needs to think what to do if we reach + * here anyway. + */ + printk (KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n"); + return; + } + ireason.all=IN_BYTE (IDE_IREASON_REG); + if (!ireason.b.cod || ireason.b.io) { + printk (KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing a packet command\n"); + ide_do_reset (drive); + return; + } + atapi_output_bytes (drive,pc->c,12); /* Send the actual packet */ +#ifdef CONFIG_BLK_DEV_TRITON + if (dma_ok) { /* Begin DMA, if necessary */ + set_bit (PC_DMA_IN_PROGRESS, &pc->flags); + (void) (HWIF(drive)->dmaproc(ide_dma_begin, drive)); + } +#endif /* CONFIG_BLK_DEV_TRITON */ +} + +static void idetape_media_access_finished (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc = tape->pc; + idetape_status_reg_t status; + + status.all = GET_STAT(); + if (status.b.dsc) { + if (status.b.check) { /* Error detected */ + printk (KERN_ERR "ide-tape: %s: I/O error, ",tape->name); + idetape_retry_pc (drive); /* Retry operation */ + return; + } + pc->error = 0; + if (tape->failed_pc == pc) + tape->failed_pc = NULL; + } else { + pc->error = IDETAPE_ERROR_GENERAL; + tape->failed_pc = NULL; + } + pc->callback (drive); +} + +/* + * General packet command callback function. + */ +static void idetape_pc_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Reached idetape_pc_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + idetape_end_request (tape->pc->error ? 0:1, HWGROUP(drive)); +} + +static void idetape_rw_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + struct request *rq = HWGROUP(drive)->rq; + int blocks = tape->pc->actually_transferred / tape->tape_block_size; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Reached idetape_rw_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + tape->block_address += blocks; + rq->current_nr_sectors -= blocks; + + if (!tape->pc->error) + idetape_end_request (1, HWGROUP (drive)); + else + idetape_end_request (tape->pc->error, HWGROUP (drive)); +} + +static void idetape_create_locate_cmd (idetape_pc_t *pc, unsigned int block, byte partition) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_LOCATE_CMD; + pc->c[1] = 2; + put_unaligned (htonl (block), (unsigned int *) &pc->c[3]); + pc->c[8] = partition; + set_bit (PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_rewind_cmd (idetape_pc_t *pc) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_REWIND_CMD; + set_bit (PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +/* + * A mode sense command is used to "sense" tape parameters. + */ +static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, byte page_code) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_MODE_SENSE_CMD; + pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors for now */ + pc->c[2] = page_code; + pc->c[3] = 255; /* Don't limit the returned information */ + pc->c[4] = 255; /* (We will just discard data in that case) */ + if (page_code == IDETAPE_CAPABILITIES_PAGE) + pc->request_transfer = 24; +#if IDETAPE_DEBUG_BUGS + else + printk (KERN_ERR "ide-tape: unsupported page code in create_mode_sense_cmd\n"); +#endif /* IDETAPE_DEBUG_BUGS */ + pc->callback = &idetape_pc_callback; +} + +/* + * idetape_create_write_filemark_cmd will: + * + * 1. Write a filemark if write_filemark=1. + * 2. Flush the device buffers without writing a filemark + * if write_filemark=0. + * + */ +static void idetape_create_write_filemark_cmd (idetape_pc_t *pc,int write_filemark) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD; + pc->c[4] = write_filemark; + set_bit (PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_load_unload_cmd (idetape_pc_t *pc,int cmd) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_LOAD_UNLOAD_CMD; + pc->c[4] = cmd; + set_bit (PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_erase_cmd (idetape_pc_t *pc) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_ERASE_CMD; + pc->c[1] = 1; + set_bit (PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_read_cmd (idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct buffer_head *bh) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_READ_CMD; + put_unaligned (htonl (length), (unsigned int *) &pc->c[1]); + pc->c[1] = 1; + pc->callback = &idetape_rw_callback; + pc->bh = bh; + bh->b_count = 0; + pc->buffer = NULL; + pc->request_transfer = pc->buffer_size = length * tape->tape_block_size; + if (pc->request_transfer == tape->stage_size) + set_bit (PC_DMA_RECOMMENDED, &pc->flags); +} + +static void idetape_create_space_cmd (idetape_pc_t *pc,int count,byte cmd) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_SPACE_CMD; + put_unaligned (htonl (count), (unsigned int *) &pc->c[1]); + pc->c[1] = cmd; + set_bit (PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_write_cmd (idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct buffer_head *bh) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_WRITE_CMD; + put_unaligned (htonl (length), (unsigned int *) &pc->c[1]); + pc->c[1] = 1; + pc->callback = &idetape_rw_callback; + set_bit (PC_WRITING, &pc->flags); + pc->bh = bh; + pc->b_data = bh->b_data; + pc->b_count = bh->b_count; + pc->buffer = NULL; + pc->request_transfer = pc->buffer_size = length * tape->tape_block_size; + if (pc->request_transfer == tape->stage_size) + set_bit (PC_DMA_RECOMMENDED, &pc->flags); +} + +static void idetape_read_position_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_read_position_result_t *result; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Reached idetape_read_position_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (!tape->pc->error) { + result = (idetape_read_position_result_t *) tape->pc->buffer; +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "BOP - %s\n",result->bop ? "Yes":"No"); + printk (KERN_INFO "EOP - %s\n",result->eop ? "Yes":"No"); +#endif /* IDETAPE_DEBUG_LOG */ + if (result->bpu) { + printk (KERN_INFO "ide-tape: Block location is unknown to the tape\n"); + clear_bit (IDETAPE_ADDRESS_VALID, &tape->flags); + idetape_end_request (0,HWGROUP (drive)); + } else { +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Block Location - %lu\n", ntohl (result->first_block)); +#endif /* IDETAPE_DEBUG_LOG */ + tape->partition = result->partition; + tape->block_address = ntohl (result->first_block); + set_bit (IDETAPE_ADDRESS_VALID, &tape->flags); + idetape_end_request (1,HWGROUP (drive)); + } + } else + idetape_end_request (0,HWGROUP (drive)); +} + +static void idetape_create_read_position_cmd (idetape_pc_t *pc) +{ + idetape_init_pc (pc); + pc->c[0] = IDETAPE_READ_POSITION_CMD; + pc->request_transfer = 20; + pc->callback = &idetape_read_position_callback; +} + +/* + * idetape_do_request is our request handling function. + */ +static void idetape_do_request (ide_drive_t *drive, struct request *rq, unsigned long block) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc; + struct blk_dev_struct *bdev = &blk_dev[HWIF(drive)->major]; + struct request *postponed_rq = tape->postponed_rq; + idetape_status_reg_t status; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "rq_status: %d, rq_dev: %u, cmd: %d, errors: %d\n",rq->rq_status,(unsigned int) rq->rq_dev,rq->cmd,rq->errors); + printk (KERN_INFO "sector: %ld, nr_sectors: %ld, current_nr_sectors: %ld\n",rq->sector,rq->nr_sectors,rq->current_nr_sectors); +#endif /* IDETAPE_DEBUG_LOG */ + + if (!IDETAPE_RQ_CMD (rq->cmd)) { + /* + * We do not support buffer cache originated requests. + */ + printk (KERN_NOTICE "ide-tape: %s: Unsupported command in request queue\n", drive->name); + ide_end_request (0,HWGROUP (drive)); /* Let the common code handle it */ + return; + } + + /* + * This is an important point. We will try to remove our request + * from the block device request queue while we service the + * request. Note that the request must be returned to + * bdev->current_request before the next call to + * ide_end_drive_cmd or ide_do_drive_cmd to conform with the + * normal behavior of the IDE driver, which leaves the active + * request in bdev->current_request during I/O. + * + * This will eliminate fragmentation of disk/cdrom requests + * around a tape request, now that we are using ide_next to + * insert pending pipeline requests, since we have only one + * ide-tape.c data request in the device request queue, and + * thus once removed, ll_rw_blk.c will only see requests from + * the other device. + * + * The potential fragmentation inefficiency was pointed to me + * by Mark Lord. + * + * Uhuh.. the following "fix" is actually not entirely correct. + * Some day we should probably move to a per device request + * queue, rather than per interface. + */ + if (rq->next != NULL && rq->rq_dev != rq->next->rq_dev) + bdev->current_request=rq->next; + + /* + * Retry a failed packet command + */ + if (tape->failed_pc != NULL && tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) { + idetape_issue_packet_command (drive, tape->failed_pc); + return; + } +#if IDETAPE_DEBUG_BUGS + if (postponed_rq != NULL) + if (postponed_rq->rq_status != RQ_ACTIVE || rq != postponed_rq) { + printk (KERN_ERR "ide-tape: ide-tape.c bug - Two DSC requests were queued\n"); + idetape_end_request (0,HWGROUP (drive)); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + + tape->postponed_rq = NULL; + + /* + * If the tape is still busy, postpone our request and service + * the other device meanwhile. + */ + status.all = GET_STAT(); + if (!clear_bit (IDETAPE_IGNORE_DSC, &tape->flags) && !status.b.dsc) { + if (postponed_rq == NULL) { + tape->dsc_polling_start = jiffies; + tape->dsc_polling_frequency = tape->best_dsc_rw_frequency; + tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT; + } else if ((signed long) (jiffies - tape->dsc_timeout) > 0) { + printk (KERN_ERR "ide-tape: %s: DSC timeout\n", tape->name); + if (rq->cmd == IDETAPE_PC_RQ) + idetape_media_access_finished (drive); + else + ide_do_reset (drive); + return; + } else if (jiffies - tape->dsc_polling_start > IDETAPE_DSC_MA_THRESHOLD) + tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW; + idetape_postpone_request (drive); + return; + } + switch (rq->cmd) { + case IDETAPE_READ_RQ: + pc=idetape_next_pc_storage (drive); + idetape_create_read_cmd (tape, pc, rq->current_nr_sectors, rq->bh); + break; + case IDETAPE_WRITE_RQ: + pc=idetape_next_pc_storage (drive); + idetape_create_write_cmd (tape, pc, rq->current_nr_sectors, rq->bh); + break; + case IDETAPE_ABORTED_WRITE_RQ: + rq->cmd = IDETAPE_WRITE_RQ; + rq->errors = IDETAPE_ERROR_EOD; + idetape_end_request (1, HWGROUP(drive)); + return; + case IDETAPE_PC_RQ: + if (postponed_rq != NULL) { + idetape_media_access_finished (drive); + return; + } + pc=(idetape_pc_t *) rq->buffer; + break; + default: + printk (KERN_ERR "ide-tape: bug in IDETAPE_RQ_CMD macro\n"); + idetape_end_request (0,HWGROUP (drive)); + return; + } + idetape_issue_packet_command (drive, pc); +} + +/* + * idetape_queue_pc_tail is based on the following functions: + * + * ide_do_drive_cmd from ide.c + * cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c + * + * We add a special packet command request to the tail of the request queue, + * and wait for it to be serviced. + * + * This is not to be called from within the request handling part + * of the driver ! We allocate here data in the stack, and it is valid + * until the request is finished. This is not the case for the bottom + * part of the driver, where we are always leaving the functions to wait + * for an interrupt or a timer event. + * + * From the bottom part of the driver, we should allocate safe memory + * using idetape_next_pc_storage and idetape_next_rq_storage, and add + * the request to the request list without waiting for it to be serviced ! + * In that case, we usually use idetape_queue_pc_head. + */ +static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc) +{ + struct request rq; + + ide_init_drive_cmd (&rq); + rq.buffer = (char *) pc; + rq.cmd = IDETAPE_PC_RQ; + return ide_do_drive_cmd (drive, &rq, ide_wait); +} + +/* + * idetape_wait_for_request installs a semaphore in a pending request + * and sleeps until it is serviced. + * + * The caller should ensure that the request will not be serviced + * before we install the semaphore (usually by disabling interrupts). + */ +static void idetape_wait_for_request (struct request *rq) +{ + struct semaphore sem = MUTEX_LOCKED; + +#if IDETAPE_DEBUG_BUGS + if (rq == NULL || !IDETAPE_RQ_CMD (rq->cmd)) { + printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + rq->sem = &sem; + down (&sem); +} + +/* + * idetape_queue_rw_tail generates a read/write request for the block + * device interface and wait for it to be serviced. + */ +static int idetape_queue_rw_tail (ide_drive_t *drive, int cmd, int blocks, struct buffer_head *bh) +{ + idetape_tape_t *tape = drive->driver_data; + struct request rq; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "idetape_queue_rw_tail: cmd=%d\n",cmd); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (idetape_pipeline_active (tape)) { + printk (KERN_ERR "ide-tape: bug: the pipeline is active in idetape_queue_rw_tail\n"); + return (0); + } +#endif /* IDETAPE_DEBUG_BUGS */ + + ide_init_drive_cmd (&rq); + rq.bh = bh; + rq.cmd = cmd; + rq.sector = tape->block_address; + rq.nr_sectors = rq.current_nr_sectors = blocks; + (void) ide_do_drive_cmd (drive, &rq, ide_wait); + + idetape_init_merge_stage (tape); + if (rq.errors == IDETAPE_ERROR_GENERAL) + return -EIO; + return (tape->tape_block_size * (blocks-rq.current_nr_sectors)); +} + +/* + * idetape_add_chrdev_read_request is called from idetape_chrdev_read + * to service a character device read request and add read-ahead + * requests to our pipeline. + */ +static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *new_stage; + unsigned long flags; + struct request rq,*rq_ptr; + int bytes_read; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_add_chrdev_read_request\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + ide_init_drive_cmd (&rq); + rq.cmd = IDETAPE_READ_RQ; + rq.sector = tape->block_address; + rq.nr_sectors = rq.current_nr_sectors = blocks; + + if (idetape_pipeline_active (tape) || tape->nr_stages <= tape->max_stages / 4) { + new_stage=idetape_kmalloc_stage (tape); + while (new_stage != NULL) { + new_stage->rq=rq; + idetape_add_stage_tail (drive,new_stage); + new_stage=idetape_kmalloc_stage (tape); + } + if (!idetape_pipeline_active (tape)) + idetape_insert_pipeline_into_queue (drive); + } + if (tape->first_stage == NULL) { + /* + * Linux is short on memory. Revert to non-pipelined + * operation mode for this request. + */ + return (idetape_queue_rw_tail (drive, IDETAPE_READ_RQ, blocks, tape->merge_stage->bh)); + } + save_flags (flags); + cli (); + if (tape->active_stage == tape->first_stage) + idetape_wait_for_request (tape->active_data_request); + restore_flags (flags); + + rq_ptr = &tape->first_stage->rq; + bytes_read = tape->tape_block_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors); + rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0; + + idetape_switch_buffers (tape, tape->first_stage); + + if (rq_ptr->errors != IDETAPE_ERROR_FILEMARK) { + clear_bit (IDETAPE_FILEMARK, &tape->flags); + idetape_remove_stage_head (drive); + } else + set_bit (IDETAPE_FILEMARK, &tape->flags); +#if IDETAPE_DEBUG_BUGS + if (bytes_read > blocks*tape->tape_block_size) { + printk (KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n"); + bytes_read=blocks*tape->tape_block_size; + } +#endif /* IDETAPE_DEBUG_BUGS */ + return (bytes_read); +} + +/* + * idetape_add_chrdev_write_request tries to add a character device + * originated write request to our pipeline. In case we don't succeed, + * we revert to non-pipelined operation mode for this request. + * + * 1. Try to allocate a new pipeline stage. + * 2. If we can't, wait for more and more requests to be serviced + * and try again each time. + * 3. If we still can't allocate a stage, fallback to + * non-pipelined operation mode for this request. + */ +static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *new_stage; + unsigned long flags; + struct request *rq; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_add_chrdev_write_request\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + /* + * Attempt to allocate a new stage. + * Pay special attention to possible race conditions. + */ + while ((new_stage = idetape_kmalloc_stage (tape)) == NULL) { + save_flags (flags); + cli (); + if (idetape_pipeline_active (tape)) { + idetape_wait_for_request (tape->active_data_request); + restore_flags (flags); + } else { + restore_flags (flags); + idetape_insert_pipeline_into_queue (drive); + if (idetape_pipeline_active (tape)) + continue; + /* + * Linux is short on memory. Fallback to + * non-pipelined operation mode for this request. + */ + return idetape_queue_rw_tail (drive, IDETAPE_WRITE_RQ, blocks, tape->merge_stage->bh); + } + } + rq = &new_stage->rq; + ide_init_drive_cmd (rq); + rq->cmd = IDETAPE_WRITE_RQ; + rq->sector = tape->block_address; /* Doesn't actually matter - We always assume sequential access */ + rq->nr_sectors = rq->current_nr_sectors = blocks; + + idetape_switch_buffers (tape, new_stage); + idetape_add_stage_tail (drive,new_stage); + + /* + * Check if we are currently servicing requests in the bottom + * part of the driver. + * + * If not, wait for the pipeline to be full enough (75%) before + * starting to service requests, so that we will be able to + * keep up with the higher speeds of the tape. + */ + if (!idetape_pipeline_active (tape) && tape->nr_stages >= (3 * tape->max_stages) / 4) + idetape_insert_pipeline_into_queue (drive); + + if (clear_bit (IDETAPE_PIPELINE_ERROR, &tape->flags)) /* Return a deferred error */ + return -EIO; + return blocks; +} + +static void idetape_discard_read_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + +#if IDETAPE_DEBUG_BUGS + if (tape->chrdev_direction != idetape_direction_read) { + printk (KERN_ERR "ide-tape: bug: Trying to discard read pipeline, but we are not reading.\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + tape->merge_stage_size = 0; + if (tape->merge_stage != NULL) { + __idetape_kfree_stage (tape->merge_stage); + tape->merge_stage = NULL; + } + tape->chrdev_direction = idetape_direction_none; + + if (tape->first_stage == NULL) + return; + + save_flags (flags); + cli (); + tape->next_stage = NULL; + if (idetape_pipeline_active (tape)) + idetape_wait_for_request (tape->active_data_request); + restore_flags (flags); + + while (tape->first_stage != NULL) + idetape_remove_stage_head (drive); + tape->nr_pending_stages = 0; + tape->max_stages = IDETAPE_MIN_PIPELINE_STAGES; +} + +/* + * idetape_wait_for_pipeline will wait until all pending pipeline + * requests are serviced. Typically called on device close. + */ +static void idetape_wait_for_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + + if (!idetape_pipeline_active (tape)) + idetape_insert_pipeline_into_queue (drive); + + save_flags (flags); + cli (); + if (!idetape_pipeline_active (tape)) + goto abort; +#if IDETAPE_DEBUG_BUGS + if (tape->last_stage == NULL) + printk ("ide-tape: tape->last_stage == NULL\n"); + else +#endif /* IDETAPE_DEBUG_BUGS */ + idetape_wait_for_request (&tape->last_stage->rq); +abort: + restore_flags (flags); +} + +static void idetape_pad_zeros (ide_drive_t *drive, int bcount) +{ + idetape_tape_t *tape = drive->driver_data; + struct buffer_head *bh; + int count, blocks; + + while (bcount) { + bh = tape->merge_stage->bh; + count = IDETAPE_MIN (tape->stage_size, bcount); + bcount -= count; + blocks = count / tape->tape_block_size; + while (count) { + bh->b_count = IDETAPE_MIN (count, bh->b_size); + memset (bh->b_data, 0, bh->b_count); + count -= bh->b_count; + bh = bh->b_reqnext; + } + idetape_queue_rw_tail (drive, IDETAPE_WRITE_RQ, blocks, tape->merge_stage->bh); + } +} + +static void idetape_empty_write_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + int blocks, i; + +#if IDETAPE_DEBUG_BUGS + if (tape->chrdev_direction != idetape_direction_write) { + printk (KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n"); + return; + } + if (tape->merge_stage_size > tape->stage_size) { + printk (KERN_ERR "ide-tape: bug: merge_buffer too big\n"); + tape->merge_stage_size = tape->stage_size; + } +#endif /* IDETAPE_DEBUG_BUGS */ + if (tape->merge_stage_size) { + blocks=tape->merge_stage_size/tape->tape_block_size; + if (tape->merge_stage_size % tape->tape_block_size) { + blocks++; + i = tape->tape_block_size - tape->merge_stage_size % tape->tape_block_size; + memset (tape->merge_stage->bh->b_data + tape->merge_stage->bh->b_count, 0, i); + tape->merge_stage->bh->b_count += i; + } + (void) idetape_add_chrdev_write_request (drive, blocks); + tape->merge_stage_size = 0; + } + idetape_wait_for_pipeline (drive); + if (tape->merge_stage != NULL) { + __idetape_kfree_stage (tape->merge_stage); + tape->merge_stage = NULL; + } + clear_bit (IDETAPE_PIPELINE_ERROR, &tape->flags); + tape->chrdev_direction=idetape_direction_none; + + /* + * On the next backup, perform the feedback loop again. + * (I don't want to keep sense information between backups, + * as some systems are constantly on, and the system load + * can be totally different on the next backup). + */ + tape->max_stages = IDETAPE_MIN_PIPELINE_STAGES; +#if IDETAPE_DEBUG_BUGS + if (tape->first_stage != NULL || tape->next_stage != NULL || tape->last_stage != NULL || tape->nr_stages != 0) { + printk (KERN_ERR "ide-tape: ide-tape pipeline bug\n"); + } +#endif /* IDETAPE_DEBUG_BUGS */ +} + +static int idetape_pipeline_size (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage; + struct request *rq; + int size = 0; + + idetape_wait_for_pipeline (drive); + stage = tape->first_stage; + while (stage != NULL) { + rq = &stage->rq; + size += tape->tape_block_size * (rq->nr_sectors-rq->current_nr_sectors); + if (rq->errors == IDETAPE_ERROR_FILEMARK) + size += tape->tape_block_size; + stage = stage->next; + } + size += tape->merge_stage_size; + return size; +} + +/* + * idetape_position_tape positions the tape to the requested block + * using the LOCATE packet command. A READ POSITION command is then + * issued to check where we are positioned. + * + * Like all higher level operations, we queue the commands at the tail + * of the request queue and wait for their completion. + * + */ +static int idetape_position_tape (ide_drive_t *drive, unsigned int block, byte partition) +{ + int retval; + idetape_pc_t pc; + + idetape_create_locate_cmd (&pc, block, partition); + retval=idetape_queue_pc_tail (drive,&pc); + if (retval) return (retval); + + idetape_create_read_position_cmd (&pc); + return (idetape_queue_pc_tail (drive,&pc)); +} + +/* + * Rewinds the tape to the Beginning Of the current Partition (BOP). + * + * We currently support only one partition. + */ +static int idetape_rewind_tape (ide_drive_t *drive) +{ + int retval; + idetape_pc_t pc; +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_rewind_tape\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + idetape_create_rewind_cmd (&pc); + retval=idetape_queue_pc_tail (drive,&pc); + if (retval) return (retval); + + idetape_create_read_position_cmd (&pc); + return (idetape_queue_pc_tail (drive,&pc)); +} + +static int idetape_flush_tape_buffers (ide_drive_t *drive) +{ + idetape_pc_t pc; + + idetape_create_write_filemark_cmd (&pc,0); + return (idetape_queue_pc_tail (drive,&pc)); +} + +/* + * Our special ide-tape ioctl's. + * + * Currently there aren't any ioctl's. + * mtio.h compatible commands should be issued to the character device + * interface. + */ +static int idetape_blkdev_ioctl (ide_drive_t *drive, struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_config_t config; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "ide-tape: Reached idetape_blkdev_ioctl\n"); +#endif /* IDETAPE_DEBUG_LOG */ + switch (cmd) { + case 0x0340: + if (copy_from_user ((char *) &config, (char *) arg, sizeof (idetape_config_t))) + return -EFAULT; + tape->best_dsc_rw_frequency = config.dsc_rw_frequency; + tape->max_stages = config.nr_stages; + break; + case 0x0350: + config.dsc_rw_frequency = (int) tape->best_dsc_rw_frequency; + config.nr_stages = tape->max_stages; + if (copy_to_user ((char *) arg, (char *) &config, sizeof (idetape_config_t))) + return -EFAULT; + break; + default: + return -EIO; + } + return 0; +} + +/* + * The block device interface should not be used for data transfers. + * However, we still allow opening it so that we can issue general + * ide driver configuration ioctl's, such as the interrupt unmask feature. + */ +static int idetape_blkdev_open (struct inode *inode, struct file *filp, ide_drive_t *drive) +{ + MOD_INC_USE_COUNT; + return 0; +} + +static void idetape_blkdev_release (struct inode *inode, struct file *filp, ide_drive_t *drive) +{ + MOD_DEC_USE_COUNT; +} + +/* + * idetape_pre_reset is called before an ATAPI/ATA software reset. + */ +static void idetape_pre_reset (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + if (tape != NULL) + set_bit (IDETAPE_IGNORE_DSC, &tape->flags); +} + +/* + * Character device interface functions + */ +static ide_drive_t *get_drive_ptr (kdev_t i_rdev) +{ + unsigned int i = MINOR(i_rdev) & ~0x80; + + if (i >= MAX_HWIFS * MAX_DRIVES) + return NULL; + return (idetape_chrdevs[i].drive); +} + +/* + * idetape_space_over_filemarks is now a bit more complicated than just + * passing the command to the tape since we may have crossed some + * filemarks during our pipelined read-ahead mode. + * + * As a minor side effect, the pipeline enables us to support MTFSFM when + * the filemark is in our internal pipeline even if the tape doesn't + * support spacing over filemarks in the reverse direction. + */ +static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + unsigned long flags; + int retval,count=0; + + if (tape->chrdev_direction == idetape_direction_read) { + + /* + * We have a read-ahead buffer. Scan it for crossed + * filemarks. + */ + tape->merge_stage_size = 0; + clear_bit (IDETAPE_FILEMARK, &tape->flags); + while (tape->first_stage != NULL) { + /* + * Wait until the first read-ahead request + * is serviced. + */ + save_flags (flags); + cli (); + if (tape->active_stage == tape->first_stage) + idetape_wait_for_request (tape->active_data_request); + restore_flags (flags); + + if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK) + count++; + if (count == mt_count) { + switch (mt_op) { + case MTFSF: + idetape_remove_stage_head (drive); + case MTFSFM: + return (0); + default: + break; + } + } + idetape_remove_stage_head (drive); + } + idetape_discard_read_pipeline (drive); + } + + /* + * The filemark was not found in our internal pipeline. + * Now we can issue the space command. + */ + switch (mt_op) { + case MTFSF: + idetape_create_space_cmd (&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK); + return (idetape_queue_pc_tail (drive,&pc)); + case MTFSFM: + if (!tape->capabilities.sprev) + return (-EIO); + retval = idetape_space_over_filemarks (drive, MTFSF, mt_count-count); + if (retval) return (retval); + return (idetape_space_over_filemarks (drive, MTBSF, 1)); + case MTBSF: + if (!tape->capabilities.sprev) + return (-EIO); + idetape_create_space_cmd (&pc,-(mt_count+count),IDETAPE_SPACE_OVER_FILEMARK); + return (idetape_queue_pc_tail (drive,&pc)); + case MTBSFM: + if (!tape->capabilities.sprev) + return (-EIO); + retval = idetape_space_over_filemarks (drive, MTBSF, mt_count+count); + if (retval) return (retval); + return (idetape_space_over_filemarks (drive, MTFSF, 1)); + default: + printk (KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op); + return (-EIO); + } +} + + +/* + * Our character device read / write functions. + * + * The tape is optimized to maximize throughput when it is transferring + * an integral number of the "continuous transfer limit", which is + * a parameter of the specific tape (26 KB on my particular tape). + * + * As of version 1.3 of the driver, the character device provides an + * abstract continuous view of the media - any mix of block sizes (even 1 + * byte) on the same backup/restore procedure is supported. The driver + * will internally convert the requests to the recommended transfer unit, + * so that an unmatch between the user's block size to the recommended + * size will only result in a (slightly) increased driver overhead, but + * will no longer hit performance. + */ +static long idetape_chrdev_read (struct inode *inode, struct file *file, char *buf, unsigned long count) +{ + ide_drive_t *drive = get_drive_ptr (inode->i_rdev); + idetape_tape_t *tape = drive->driver_data; + int bytes_read,temp,actually_read=0, original_count = count; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_chrdev_read\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->chrdev_direction != idetape_direction_read) { /* Initialize read operation */ + if (tape->chrdev_direction == idetape_direction_write) { + idetape_empty_write_pipeline (drive); + idetape_flush_tape_buffers (drive); + } +#if IDETAPE_DEBUG_BUGS + if (tape->merge_stage || tape->merge_stage_size) { + printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n"); + tape->merge_stage_size = 0; + } +#endif /* IDETAPE_DEBUG_BUGS */ + if ((tape->merge_stage = __idetape_kmalloc_stage (tape)) == NULL) + return -ENOMEM; + tape->chrdev_direction = idetape_direction_read; + + /* + * Issue a read 0 command to ensure that DSC handshake + * is switched from completion mode to buffer available + * mode. + */ + bytes_read = idetape_queue_rw_tail (drive, IDETAPE_READ_RQ, 0, tape->merge_stage->bh); + if (bytes_read < 0) { + kfree (tape->merge_stage); + tape->merge_stage = NULL; + tape->chrdev_direction = idetape_direction_none; + return bytes_read; + } + if (test_bit (IDETAPE_DETECT_BS, &tape->flags)) + if (count > tape->tape_block_size && (count % tape->tape_block_size) == 0) + tape->user_bs_factor = count / tape->tape_block_size; + } + if (count==0) + return (0); + if (tape->merge_stage_size) { + actually_read=IDETAPE_MIN (tape->merge_stage_size,count); + idetape_copy_stage_to_user (tape, buf, tape->merge_stage, actually_read); + buf += actually_read; tape->merge_stage_size -= actually_read; count-=actually_read; + } + while (count >= tape->stage_size) { + bytes_read=idetape_add_chrdev_read_request (drive, tape->capabilities.ctl); + if (bytes_read <= 0) + goto finish; + idetape_copy_stage_to_user (tape, buf, tape->merge_stage, bytes_read); + buf += bytes_read; count -= bytes_read; actually_read += bytes_read; + } + if (count) { + bytes_read=idetape_add_chrdev_read_request (drive, tape->capabilities.ctl); + if (bytes_read <= 0) + goto finish; + temp=IDETAPE_MIN (count,bytes_read); + idetape_copy_stage_to_user (tape, buf, tape->merge_stage, temp); + actually_read+=temp; + tape->merge_stage_size=bytes_read-temp; + } +finish: + if (actually_read < original_count && test_bit (IDETAPE_FILEMARK, &tape->flags)) + idetape_space_over_filemarks (drive, MTFSF, 1); + return (actually_read); +} + +static long idetape_chrdev_write (struct inode *inode, struct file *file, const char *buf, unsigned long count) +{ + ide_drive_t *drive = get_drive_ptr (inode->i_rdev); + idetape_tape_t *tape = drive->driver_data; + int retval,actually_written=0; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_chrdev_write\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->chrdev_direction != idetape_direction_write) { /* Initialize write operation */ + if (tape->chrdev_direction == idetape_direction_read) + idetape_discard_read_pipeline (drive); +#if IDETAPE_DEBUG_BUGS + if (tape->merge_stage || tape->merge_stage_size) { + printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n"); + tape->merge_stage_size = 0; + } +#endif /* IDETAPE_DEBUG_BUGS */ + if ((tape->merge_stage = __idetape_kmalloc_stage (tape)) == NULL) + return -ENOMEM; + tape->chrdev_direction = idetape_direction_write; + idetape_init_merge_stage (tape); + + /* + * Issue a write 0 command to ensure that DSC handshake + * is switched from completion mode to buffer available + * mode. + */ + retval = idetape_queue_rw_tail (drive, IDETAPE_WRITE_RQ, 0, tape->merge_stage->bh); + if (retval < 0) { + kfree (tape->merge_stage); + tape->merge_stage = NULL; + tape->chrdev_direction = idetape_direction_none; + return retval; + } + if (test_bit (IDETAPE_DETECT_BS, &tape->flags)) + if (count > tape->tape_block_size && (count % tape->tape_block_size) == 0) + tape->user_bs_factor = count / tape->tape_block_size; + } + if (count==0) + return (0); + if (tape->merge_stage_size) { +#if IDETAPE_DEBUG_BUGS + if (tape->merge_stage_size >= tape->stage_size) { + printk (KERN_ERR "ide-tape: bug: merge buffer too big\n"); + tape->merge_stage_size=0; + } +#endif /* IDETAPE_DEBUG_BUGS */ + actually_written=IDETAPE_MIN (tape->stage_size-tape->merge_stage_size,count); + idetape_copy_stage_from_user (tape, tape->merge_stage, buf, actually_written); + buf+=actually_written;tape->merge_stage_size+=actually_written;count-=actually_written; + + if (tape->merge_stage_size == tape->stage_size) { + tape->merge_stage_size = 0; + retval=idetape_add_chrdev_write_request (drive, tape->capabilities.ctl); + if (retval <= 0) + return (retval); + } + } + while (count >= tape->stage_size) { + idetape_copy_stage_from_user (tape, tape->merge_stage, buf, tape->stage_size); + buf+=tape->stage_size;count-=tape->stage_size; + retval=idetape_add_chrdev_write_request (drive, tape->capabilities.ctl); + actually_written+=tape->stage_size; + if (retval <= 0) + return (retval); + } + if (count) { + actually_written+=count; + idetape_copy_stage_from_user (tape, tape->merge_stage, buf, count); + tape->merge_stage_size+=count; + } + return (actually_written); +} + +/* + * idetape_mtioctop is called from idetape_chrdev_ioctl when + * the general mtio MTIOCTOP ioctl is requested. + * + * We currently support the following mtio.h operations: + * + * MTFSF - Space over mt_count filemarks in the positive direction. + * The tape is positioned after the last spaced filemark. + * + * MTFSFM - Same as MTFSF, but the tape is positioned before the + * last filemark. + * + * MTBSF - Steps background over mt_count filemarks, tape is + * positioned before the last filemark. + * + * MTBSFM - Like MTBSF, only tape is positioned after the last filemark. + * + * Note: + * + * MTBSF and MTBSFM are not supported when the tape doesn't + * supports spacing over filemarks in the reverse direction. + * In this case, MTFSFM is also usually not supported (it is + * supported in the rare case in which we crossed the filemark + * during our read-ahead pipelined operation mode). + * + * MTWEOF - Writes mt_count filemarks. Tape is positioned after + * the last written filemark. + * + * MTREW - Rewinds tape. + * + * MTLOAD - Loads the tape. + * + * MTOFFL - Puts the tape drive "Offline": Rewinds the tape and + * MTUNLOAD prevents further access until the media is replaced. + * + * MTNOP - Flushes tape buffers. + * + * MTRETEN - Retension media. This typically consists of one end + * to end pass on the media. + * + * MTEOM - Moves to the end of recorded data. + * + * MTERASE - Erases tape. + * + * MTSETBLK - Sets the user block size to mt_count bytes. If + * mt_count is 0, we will attempt to autodetect + * the block size. + * + * MTSEEK - Positions the tape in a specific block number, where + * each block is assumed to contain which user_block_size + * bytes. + * + * MTSETPART - Switches to another tape partition. + * + * The following commands are currently not supported: + * + * MTFSR, MTBSR, MTFSS, MTBSS, MTWSM, MTSETDENSITY, + * MTSETDRVBUFFER, MT_ST_BOOLEANS, MT_ST_WRITE_THRESHOLD. + */ +static int idetape_mtioctop (ide_drive_t *drive,short mt_op,int mt_count) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + int i,retval; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",mt_op,mt_count); +#endif /* IDETAPE_DEBUG_LOG */ + /* + * Commands which need our pipelined read-ahead stages. + */ + switch (mt_op) { + case MTFSF: + case MTFSFM: + case MTBSF: + case MTBSFM: + if (!mt_count) + return (0); + return (idetape_space_over_filemarks (drive,mt_op,mt_count)); + default: + break; + } + + /* + * Empty the pipeline. + */ + if (tape->chrdev_direction == idetape_direction_read) + idetape_discard_read_pipeline (drive); + + switch (mt_op) { + case MTWEOF: + for (i=0;i<mt_count;i++) { + idetape_create_write_filemark_cmd (&pc,1); + retval=idetape_queue_pc_tail (drive,&pc); + if (retval) return (retval); + } + return (0); + case MTREW: + return (idetape_rewind_tape (drive)); + case MTLOAD: + idetape_create_load_unload_cmd (&pc, IDETAPE_LU_LOAD_MASK); + return (idetape_queue_pc_tail (drive,&pc)); + case MTUNLOAD: + case MTOFFL: + idetape_create_load_unload_cmd (&pc,!IDETAPE_LU_LOAD_MASK); + return (idetape_queue_pc_tail (drive,&pc)); + case MTNOP: + return (idetape_flush_tape_buffers (drive)); + case MTRETEN: + idetape_create_load_unload_cmd (&pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK); + return (idetape_queue_pc_tail (drive,&pc)); + case MTEOM: + idetape_create_space_cmd (&pc,0,IDETAPE_SPACE_TO_EOD); + return (idetape_queue_pc_tail (drive,&pc)); + case MTERASE: + (void) idetape_rewind_tape (drive); + idetape_create_erase_cmd (&pc); + return (idetape_queue_pc_tail (drive,&pc)); + case MTSETBLK: + if (mt_count) { + if (mt_count < tape->tape_block_size || mt_count % tape->tape_block_size) + return -EIO; + tape->user_bs_factor = mt_count / tape->tape_block_size; + clear_bit (IDETAPE_DETECT_BS, &tape->flags); + } else + set_bit (IDETAPE_DETECT_BS, &tape->flags); + return 0; + case MTSEEK: + return (idetape_position_tape (drive, mt_count * tape->user_bs_factor, tape->partition)); + case MTSETPART: + return (idetape_position_tape (drive, 0, mt_count)); + default: + printk (KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op); + return (-EIO); + } +} + +/* + * Our character device ioctls. + * + * General mtio.h magnetic io commands are supported here, and not in + * the corresponding block interface. + * + * The following ioctls are supported: + * + * MTIOCTOP - Refer to idetape_mtioctop for detailed description. + * + * MTIOCGET - The mt_dsreg field in the returned mtget structure + * will be set to (user block size in bytes << + * MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK. + * + * The mt_blkno is set to the current user block number. + * The other mtget fields are not supported. + * + * MTIOCPOS - The current tape "block position" is returned. We + * assume that each block contains user_block_size + * bytes. + * + * Our own ide-tape ioctls are supported on both interfaces. + */ +static int idetape_chrdev_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) +{ + ide_drive_t *drive = get_drive_ptr (inode->i_rdev); + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + struct mtop mtop; + struct mtget mtget; + struct mtpos mtpos; + int retval, block_offset = 0; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_chrdev_ioctl, cmd=%u\n",cmd); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->chrdev_direction == idetape_direction_write) { + idetape_empty_write_pipeline (drive); + idetape_flush_tape_buffers (drive); + } + if (cmd == MTIOCGET || cmd == MTIOCPOS) { + block_offset = idetape_pipeline_size (drive) / (tape->tape_block_size * tape->user_bs_factor); + idetape_create_read_position_cmd (&pc); + retval=idetape_queue_pc_tail (drive,&pc); + if (retval) return (retval); + } + switch (cmd) { + case MTIOCTOP: + if (copy_from_user ((char *) &mtop, (char *) arg, sizeof (struct mtop))) + return -EFAULT; + return (idetape_mtioctop (drive,mtop.mt_op,mtop.mt_count)); + case MTIOCGET: + memset (&mtget, 0, sizeof (struct mtget)); + mtget.mt_blkno = tape->block_address / tape->user_bs_factor - block_offset; + mtget.mt_dsreg = ((tape->tape_block_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK; + if (copy_to_user ((char *) arg,(char *) &mtget, sizeof (struct mtget))) + return -EFAULT; + return 0; + case MTIOCPOS: + mtpos.mt_blkno = tape->block_address / tape->user_bs_factor - block_offset; + if (copy_to_user ((char *) arg,(char *) &mtpos, sizeof (struct mtpos))) + return -EFAULT; + return 0; + default: + if (tape->chrdev_direction == idetape_direction_read) + idetape_discard_read_pipeline (drive); + return (idetape_blkdev_ioctl (drive,inode,file,cmd,arg)); + } +} + +/* + * Our character device open function. + */ +static int idetape_chrdev_open (struct inode *inode, struct file *filp) +{ + ide_drive_t *drive; + idetape_tape_t *tape; + idetape_pc_t pc; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_chrdev_open\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if ((drive = get_drive_ptr (inode->i_rdev)) == NULL) + return -ENXIO; + tape = drive->driver_data; + + if (set_bit (IDETAPE_BUSY, &tape->flags)) + return -EBUSY; + MOD_INC_USE_COUNT; + idetape_create_read_position_cmd (&pc); + (void) idetape_queue_pc_tail (drive,&pc); + if (!test_bit (IDETAPE_ADDRESS_VALID, &tape->flags)) + (void) idetape_rewind_tape (drive); + MOD_DEC_USE_COUNT; + + if (tape->chrdev_direction == idetape_direction_none) + MOD_INC_USE_COUNT; + return 0; +} + +/* + * Our character device release function. + */ +static void idetape_chrdev_release (struct inode *inode, struct file *filp) +{ + ide_drive_t *drive = get_drive_ptr (inode->i_rdev); + idetape_tape_t *tape = drive->driver_data; + unsigned int minor=MINOR (inode->i_rdev); + idetape_pc_t pc; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Reached idetape_chrdev_release\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->chrdev_direction == idetape_direction_write) { + idetape_empty_write_pipeline (drive); + tape->merge_stage = __idetape_kmalloc_stage (tape); + if (tape->merge_stage != NULL) { + idetape_pad_zeros (drive, tape->tape_block_size * (tape->user_bs_factor - 1)); + __idetape_kfree_stage (tape->merge_stage); + tape->merge_stage = NULL; + } + idetape_create_write_filemark_cmd (&pc,1); /* Write a filemark */ + if (idetape_queue_pc_tail (drive,&pc)) + printk (KERN_ERR "ide-tape: Couldn't write a filemark\n"); + } + if (tape->chrdev_direction == idetape_direction_read) { + if (minor < 128) + idetape_discard_read_pipeline (drive); + else + idetape_wait_for_pipeline (drive); + } + if (tape->cache_stage != NULL) { + __idetape_kfree_stage (tape->cache_stage); + tape->cache_stage = NULL; + } + if (minor < 128) + (void) idetape_rewind_tape (drive); + + clear_bit (IDETAPE_BUSY, &tape->flags); + if (tape->chrdev_direction == idetape_direction_none) + MOD_DEC_USE_COUNT; +} + +/* + * idetape_identify_device is called to check the contents of the + * ATAPI IDENTIFY command results. We return: + * + * 1 If the tape can be supported by us, based on the information + * we have so far. + * + * 0 If this tape driver is not currently supported by us. + */ +static int idetape_identify_device (ide_drive_t *drive,struct hd_driveid *id) +{ + struct idetape_id_gcw gcw; +#if IDETAPE_DEBUG_LOG + unsigned short mask,i; +#endif /* IDETAPE_DEBUG_LOG */ + + *((unsigned short *) &gcw) = id->config; + +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Dumping ATAPI Identify Device tape parameters\n"); + printk (KERN_INFO "Protocol Type: "); + switch (gcw.protocol) { + case 0: case 1: printk (KERN_INFO "ATA\n");break; + case 2: printk (KERN_INFO "ATAPI\n");break; + case 3: printk (KERN_INFO "Reserved (Unknown to ide-tape)\n");break; + } + printk (KERN_INFO "Device Type: %x - ",gcw.device_type); + switch (gcw.device_type) { + case 0: printk (KERN_INFO "Direct-access Device\n");break; + case 1: printk (KERN_INFO "Streaming Tape Device\n");break; + case 2: case 3: case 4: printk (KERN_INFO "Reserved\n");break; + case 5: printk (KERN_INFO "CD-ROM Device\n");break; + case 6: printk (KERN_INFO "Reserved\n"); + case 7: printk (KERN_INFO "Optical memory Device\n");break; + case 0x1f: printk (KERN_INFO "Unknown or no Device type\n");break; + default: printk (KERN_INFO "Reserved\n"); + } + printk (KERN_INFO "Removable: %s",gcw.removable ? "Yes\n":"No\n"); + printk (KERN_INFO "Command Packet DRQ Type: "); + switch (gcw.drq_type) { + case 0: printk (KERN_INFO "Microprocessor DRQ\n");break; + case 1: printk (KERN_INFO "Interrupt DRQ\n");break; + case 2: printk (KERN_INFO "Accelerated DRQ\n");break; + case 3: printk (KERN_INFO "Reserved\n");break; + } + printk (KERN_INFO "Command Packet Size: "); + switch (gcw.packet_size) { + case 0: printk (KERN_INFO "12 bytes\n");break; + case 1: printk (KERN_INFO "16 bytes\n");break; + default: printk (KERN_INFO "Reserved\n");break; + } + printk (KERN_INFO "Model: %s\n",id->model); + printk (KERN_INFO "Firmware Revision: %s\n",id->fw_rev); + printk (KERN_INFO "Serial Number: %s\n",id->serial_no); + printk (KERN_INFO "Write buffer size: %d bytes\n",id->buf_size*512); + printk (KERN_INFO "DMA: %s",id->capability & 0x01 ? "Yes\n":"No\n"); + printk (KERN_INFO "LBA: %s",id->capability & 0x02 ? "Yes\n":"No\n"); + printk (KERN_INFO "IORDY can be disabled: %s",id->capability & 0x04 ? "Yes\n":"No\n"); + printk (KERN_INFO "IORDY supported: %s",id->capability & 0x08 ? "Yes\n":"Unknown\n"); + printk (KERN_INFO "ATAPI overlap supported: %s",id->capability & 0x20 ? "Yes\n":"No\n"); + printk (KERN_INFO "PIO Cycle Timing Category: %d\n",id->tPIO); + printk (KERN_INFO "DMA Cycle Timing Category: %d\n",id->tDMA); + printk (KERN_INFO "Single Word DMA supported modes: "); + for (i=0,mask=1;i<8;i++,mask=mask << 1) { + if (id->dma_1word & mask) + printk (KERN_INFO "%d ",i); + if (id->dma_1word & (mask << 8)) + printk (KERN_INFO "(active) "); + } + printk (KERN_INFO "\n"); + printk (KERN_INFO "Multi Word DMA supported modes: "); + for (i=0,mask=1;i<8;i++,mask=mask << 1) { + if (id->dma_mword & mask) + printk (KERN_INFO "%d ",i); + if (id->dma_mword & (mask << 8)) + printk (KERN_INFO "(active) "); + } + printk (KERN_INFO "\n"); + if (id->field_valid & 0x0002) { + printk (KERN_INFO "Enhanced PIO Modes: %s\n",id->eide_pio_modes & 1 ? "Mode 3":"None"); + printk (KERN_INFO "Minimum Multi-word DMA cycle per word: "); + if (id->eide_dma_min == 0) + printk (KERN_INFO "Not supported\n"); + else + printk (KERN_INFO "%d ns\n",id->eide_dma_min); + + printk (KERN_INFO "Manufacturer\'s Recommended Multi-word cycle: "); + if (id->eide_dma_time == 0) + printk (KERN_INFO "Not supported\n"); + else + printk (KERN_INFO "%d ns\n",id->eide_dma_time); + + printk (KERN_INFO "Minimum PIO cycle without IORDY: "); + if (id->eide_pio == 0) + printk (KERN_INFO "Not supported\n"); + else + printk (KERN_INFO "%d ns\n",id->eide_pio); + + printk (KERN_INFO "Minimum PIO cycle with IORDY: "); + if (id->eide_pio_iordy == 0) + printk (KERN_INFO "Not supported\n"); + else + printk (KERN_INFO "%d ns\n",id->eide_pio_iordy); + + } else + printk (KERN_INFO "According to the device, fields 64-70 are not valid.\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + /* Check that we can support this device */ + + if (gcw.protocol !=2 ) + printk (KERN_ERR "ide-tape: Protocol is not ATAPI\n"); + else if (gcw.device_type != 1) + printk (KERN_ERR "ide-tape: Device type is not set to tape\n"); + else if (!gcw.removable) + printk (KERN_ERR "ide-tape: The removable flag is not set\n"); + else if (gcw.drq_type != 2) { + printk (KERN_ERR "ide-tape: Sorry, DRQ types other than Accelerated DRQ\n"); + printk (KERN_ERR "ide-tape: are still not supported by the driver\n"); + } else if (gcw.packet_size != 0) { + printk (KERN_ERR "ide-tape: Packet size is not 12 bytes long\n"); + if (gcw.packet_size == 1) + printk (KERN_ERR "ide-tape: Sorry, padding to 16 bytes is still not supported\n"); + } else + return 1; + return 0; +} + +/* + * idetape_get_mode_sense_results asks the tape about its various + * parameters. In particular, we will adjust our data transfer buffer + * size to the recommended value as returned by the tape. + */ +static void idetape_get_mode_sense_results (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + idetape_mode_parameter_header_t *header; + idetape_capabilities_page_t *capabilities; + + idetape_create_mode_sense_cmd (&pc,IDETAPE_CAPABILITIES_PAGE); + if (idetape_queue_pc_tail (drive,&pc)) { + printk (KERN_ERR "ide-tape: Can't get tape parameters - assuming some default values\n"); + tape->tape_block_size = 512; tape->capabilities.ctl = 52; + tape->capabilities.speed = 450; tape->capabilities.buffer_size = 6 * 52; + return; + } + header = (idetape_mode_parameter_header_t *) pc.buffer; + capabilities = (idetape_capabilities_page_t *) (header + 1); + + capabilities->max_speed = ntohs (capabilities->max_speed); + capabilities->ctl = ntohs (capabilities->ctl); + capabilities->speed = ntohs (capabilities->speed); + capabilities->buffer_size = ntohs (capabilities->buffer_size); + + tape->capabilities = *capabilities; /* Save us a copy */ + tape->tape_block_size = capabilities->blk512 ? 512:1024; +#if IDETAPE_DEBUG_LOG + printk (KERN_INFO "Dumping the results of the MODE SENSE packet command\n"); + printk (KERN_INFO "Mode Parameter Header:\n"); + printk (KERN_INFO "Mode Data Length - %d\n",header->mode_data_length); + printk (KERN_INFO "Medium Type - %d\n",header->medium_type); + printk (KERN_INFO "Device Specific Parameter - %d\n",header->dsp); + printk (KERN_INFO "Block Descriptor Length - %d\n",header->bdl); + + printk (KERN_INFO "Capabilities and Mechanical Status Page:\n"); + printk (KERN_INFO "Page code - %d\n",capabilities->page_code); + printk (KERN_INFO "Page length - %d\n",capabilities->page_length); + printk (KERN_INFO "Read only - %s\n",capabilities->ro ? "Yes":"No"); + printk (KERN_INFO "Supports reverse space - %s\n",capabilities->sprev ? "Yes":"No"); + printk (KERN_INFO "Supports erase initiated formatting - %s\n",capabilities->efmt ? "Yes":"No"); + printk (KERN_INFO "Supports QFA two Partition format - %s\n",capabilities->qfa ? "Yes":"No"); + printk (KERN_INFO "Supports locking the medium - %s\n",capabilities->lock ? "Yes":"No"); + printk (KERN_INFO "The volume is currently locked - %s\n",capabilities->locked ? "Yes":"No"); + printk (KERN_INFO "The device defaults in the prevent state - %s\n",capabilities->prevent ? "Yes":"No"); + printk (KERN_INFO "Supports ejecting the medium - %s\n",capabilities->eject ? "Yes":"No"); + printk (KERN_INFO "Supports error correction - %s\n",capabilities->ecc ? "Yes":"No"); + printk (KERN_INFO "Supports data compression - %s\n",capabilities->cmprs ? "Yes":"No"); + printk (KERN_INFO "Supports 512 bytes block size - %s\n",capabilities->blk512 ? "Yes":"No"); + printk (KERN_INFO "Supports 1024 bytes block size - %s\n",capabilities->blk1024 ? "Yes":"No"); + printk (KERN_INFO "Restricted byte count for PIO transfers - %s\n",capabilities->slowb ? "Yes":"No"); + printk (KERN_INFO "Maximum supported speed in KBps - %d\n",capabilities->max_speed); + printk (KERN_INFO "Continuous transfer limits in blocks - %d\n",capabilities->ctl); + printk (KERN_INFO "Current speed in KBps - %d\n",capabilities->speed); + printk (KERN_INFO "Buffer size - %d\n",capabilities->buffer_size*512); +#endif /* IDETAPE_DEBUG_LOG */ +} + +/* + * ide_setup is called to: + * + * 1. Initialize our various state variables. + * 2. Ask the tape for its capabilities. + * 3. Allocate a buffer which will be used for data + * transfer. The buffer size is chosen based on + * the recommendation which we received in step (2). + * + * Note that at this point ide.c already assigned us an irq, so that + * we can queue requests here and wait for their completion. + */ +static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor) +{ + ide_hwif_t *hwif = HWIF(drive); + unsigned long t1, tmid, tn, t; + + drive->driver_data = tape; + drive->ready_stat = 0; /* An ATAPI device ignores DRDY */ + memset (tape, 0, sizeof (idetape_tape_t)); + tape->drive = drive; + tape->minor = minor; + tape->name[0] = 'h'; tape->name[1] = 't'; tape->name[2] = '0' + minor; + tape->chrdev_direction = idetape_direction_none; + tape->pc = tape->pc_stack; + tape->max_stages = IDETAPE_MIN_PIPELINE_STAGES; + + idetape_get_mode_sense_results (drive); + + tape->user_bs_factor = 1; + tape->stage_size = tape->capabilities.ctl * tape->tape_block_size; + while (tape->stage_size > 0xffff) { + printk (KERN_NOTICE "ide-tape: decreasing stage size\n"); + tape->capabilities.ctl /= 2; + tape->stage_size = tape->capabilities.ctl * tape->tape_block_size; + } + tape->pages_per_stage = tape->stage_size / PAGE_SIZE; + if (tape->stage_size % PAGE_SIZE) { + tape->pages_per_stage++; + tape->excess_bh_size = PAGE_SIZE - tape->stage_size % PAGE_SIZE; + } + + /* + * Select the "best" DSC read/write polling frequency. + * The following algorithm attempts to find a balance between + * good latency and good system throughput. It will be nice to + * have all this configurable in run time at some point. + */ + t1 = (tape->stage_size * HZ) / (tape->capabilities.speed * 1000); + tmid = (tape->capabilities.buffer_size * 32 * HZ) / (tape->capabilities.speed * 125); + tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (tape->capabilities.speed * 1000); + + if (tape->max_stages) { + if (drive->using_dma) + t = tmid; + else { + if (hwif->drives[drive->select.b.unit ^ 1].present || hwif->next != hwif) + t = (tn + tmid) / 2; + else + t = tn; + } + } else + t = t1; + t = IDETAPE_MIN (t, tmid); + + /* + * Ensure that the number we got makes sense. + */ + tape->best_dsc_rw_frequency = IDETAPE_MAX (IDETAPE_MIN (t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN); + if (tape->best_dsc_rw_frequency != t) { + printk (KERN_NOTICE "ide-tape: Although the recommended polling period is %lu jiffies\n", t); + printk (KERN_NOTICE "ide-tape: we will use %lu jiffies\n", tape->best_dsc_rw_frequency); + } + printk (KERN_INFO "ide-tape: %s <-> %s, %dKBps, %d*%dkB buffer, %dkB pipeline, %lums tDSC%s\n", + drive->name, tape->name, tape->capabilities.speed, (tape->capabilities.buffer_size * 512) / tape->stage_size, + tape->stage_size / 1024, tape->max_stages * tape->stage_size / 1024, + tape->best_dsc_rw_frequency * 1000 / HZ, drive->using_dma ? ", DMA":""); +} + +static int idetape_cleanup (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + int minor = tape->minor; + unsigned long flags; + + save_flags (flags); + cli (); + if (test_bit (IDETAPE_BUSY, &tape->flags) || tape->first_stage != NULL || tape->merge_stage_size || drive->usage) { + restore_flags(flags); + return 1; + } + idetape_chrdevs[minor].drive = NULL; + restore_flags (flags); + DRIVER(drive)->busy = 0; + (void) ide_unregister_subdriver (drive); + drive->driver_data = NULL; + kfree (tape); + for (minor = 0; minor < MAX_HWIFS * MAX_DRIVES; minor++) + if (idetape_chrdevs[minor].drive != NULL) + return 0; + unregister_chrdev (IDETAPE_MAJOR, "ht"); + idetape_chrdev_present = 0; + return 0; +} + +int idetape_init (void); + +static ide_module_t idetape_module = { + IDE_DRIVER_MODULE, + idetape_init, + NULL +}; + +/* + * IDE subdriver functions, registered with ide.c + */ +static ide_driver_t idetape_driver = { + ide_tape, /* media */ + 1, /* busy */ + 1, /* supports_dma */ + idetape_cleanup, /* cleanup */ + idetape_do_request, /* do_request */ + idetape_end_request, /* end_request */ + idetape_blkdev_ioctl, /* ioctl */ + idetape_blkdev_open, /* open */ + idetape_blkdev_release, /* release */ + NULL, /* media_change */ + idetape_pre_reset, /* pre_reset */ + NULL, /* capacity */ + NULL /* special */ +}; + +/* + * Our character device supporting functions, passed to register_chrdev. + */ +static struct file_operations idetape_fops = { + NULL, /* lseek - default */ + idetape_chrdev_read, /* read */ + idetape_chrdev_write, /* write */ + NULL, /* readdir - bad */ + NULL, /* select */ + idetape_chrdev_ioctl, /* ioctl */ + NULL, /* mmap */ + idetape_chrdev_open, /* open */ + idetape_chrdev_release, /* release */ + NULL, /* fsync */ + NULL, /* fasync */ + NULL, /* check_media_change */ + NULL /* revalidate */ +}; + +/* + * idetape_init will register the driver for each tape. + */ +int idetape_init (void) +{ + ide_drive_t *drive; + idetape_tape_t *tape; + int minor, failed = 0, supported = 0; + + MOD_INC_USE_COUNT; + if (!idetape_chrdev_present) + for (minor = 0; minor < MAX_HWIFS * MAX_DRIVES; minor++ ) + idetape_chrdevs[minor].drive = NULL; + + if ((drive = ide_scan_devices (ide_tape, NULL, failed++)) == NULL) { + ide_register_module (&idetape_module); + MOD_DEC_USE_COUNT; + return 0; + } + if (!idetape_chrdev_present && register_chrdev (IDETAPE_MAJOR, "ht", &idetape_fops)) { + printk (KERN_ERR "ide-tape: Failed to register character device interface\n"); + MOD_DEC_USE_COUNT; + return -EBUSY; + } + do { + if (!idetape_identify_device (drive, drive->id)) { + printk (KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name); + continue; + } + tape = (idetape_tape_t *) kmalloc (sizeof (idetape_tape_t), GFP_KERNEL); + if (tape == NULL) { + printk (KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name); + continue; + } + if (ide_register_subdriver (drive, &idetape_driver, IDE_SUBDRIVER_VERSION)) { + printk (KERN_ERR "ide-tape: %s: Failed to register the driver with ide.c\n", drive->name); + kfree (tape); + continue; + } + for (minor = 0; idetape_chrdevs[minor].drive != NULL; minor++); + idetape_setup (drive, tape, minor); + idetape_chrdevs[minor].drive = drive; + supported++; failed--; + } while ((drive = ide_scan_devices (ide_tape, NULL, failed++)) != NULL); + if (!idetape_chrdev_present && !supported) { + unregister_chrdev (IDETAPE_MAJOR, "ht"); + } else + idetape_chrdev_present = 1; + ide_register_module (&idetape_module); + MOD_DEC_USE_COUNT; + return 0; +} + +#ifdef MODULE +int init_module (void) +{ + return idetape_init (); +} + +void cleanup_module (void) +{ + ide_drive_t *drive; + int minor; + + for (minor = 0; minor < MAX_HWIFS * MAX_DRIVES; minor++) { + drive = idetape_chrdevs[minor].drive; + if (drive != NULL && idetape_cleanup (drive)) + printk (KERN_ERR "ide-tape: %s: cleanup_module() called while still busy\n", drive->name); + } + ide_unregister_module(&idetape_module); +} +#endif /* MODULE */ |