/* * linux/drivers/block/ide-tape.c Version 1.10 - BETA Nov 5, 1996 * * Copyright (C) 1995, 1996 Gadi Oxman * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Main Linux ide driver include file */ #include "ide.h" /* * For general magnetic tape device compatibility. */ #include /**************************** 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;itape_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 */