diff options
Diffstat (limited to 'drivers/scsi/hosts.h')
| -rw-r--r-- | drivers/scsi/hosts.h | 92 |
1 files changed, 85 insertions, 7 deletions
diff --git a/drivers/scsi/hosts.h b/drivers/scsi/hosts.h index d7e366350..f41438eea 100644 --- a/drivers/scsi/hosts.h +++ b/drivers/scsi/hosts.h @@ -127,10 +127,34 @@ typedef struct SHT * # and exit result when the command is complete. * Host number is the POSITION IN THE hosts array of THIS * host adapter. + * + * The done() function must only be called after QueueCommand() + * has returned. */ int (* queuecommand)(Scsi_Cmnd *, void (*done)(Scsi_Cmnd *)); /* + * This is an error handling strategy routine. You don't need to + * define one of these if you don't want to - there is a default + * routine that is present that should work in most cases. For those + * driver authors that have the inclination and ability to write their + * own strategy routine, this is where it is specified. Note - the + * strategy routine is *ALWAYS* run in the context of the kernel eh + * thread. Thus you are guaranteed to *NOT* be in an interrupt handler + * when you execute this, and you are also guaranteed to *NOT* have any + * other commands being queued while you are in the strategy routine. + * When you return from this function, operations return to normal. + * + * See scsi_error.c scsi_unjam_host for additional comments about what + * this function should and should not be attempting to do. + */ + int (*eh_strategy_handler)(struct Scsi_Host *); + int (*eh_abort_handler)(Scsi_Cmnd *); + int (*eh_device_reset_handler)(Scsi_Cmnd *); + int (*eh_bus_reset_handler)(Scsi_Cmnd *); + int (*eh_host_reset_handler)(Scsi_Cmnd *); + + /* * Since the mid level driver handles time outs, etc, we want to * be able to abort the current command. Abort returns 0 if the * abortion was successful. The field SCpnt->abort reason @@ -143,6 +167,9 @@ typedef struct SHT * * Note that the scsi driver should "clean up" after itself, * resetting the bus, etc. if necessary. + * + * NOTE - this interface is depreciated, and will go away. Use + * the eh_ routines instead. */ int (* abort)(Scsi_Cmnd *); @@ -155,6 +182,9 @@ typedef struct SHT * the first place. Some hosts do not implement a reset function, * and these hosts must call scsi_request_sense(SCpnt) to keep * the command alive. + * + * NOTE - this interface is depreciated, and will go away. Use + * the eh_ routines instead. */ int (* reset)(Scsi_Cmnd *, unsigned int); @@ -227,6 +257,13 @@ typedef struct SHT */ unsigned use_clustering:1; + /* + * True if this driver uses the new error handling code. This flag is + * really only temporary until all of the other drivers get converted + * to use the new error handling code. + */ + unsigned use_new_eh_code:1; + } Scsi_Host_Template; /* @@ -240,14 +277,40 @@ typedef struct SHT struct Scsi_Host { - struct Scsi_Host * next; +/* private: */ + /* + * This information is private to the scsi mid-layer. Wrapping it in a + * struct private is a way of marking it in a sort of C++ type of way. + */ + struct Scsi_Host * next; + Scsi_Device * host_queue; + /* + * List of commands that have been rejected because either the host + * or the device was busy. These need to be retried relatively quickly, + * but we need to hold onto it for a short period until the host/device + * is available. + */ + Scsi_Cmnd * pending_commands; + + struct task_struct * ehandler; /* Error recovery thread. */ + struct semaphore * eh_wait; /* The error recovery thread waits on + this. */ + struct semaphore * eh_notify; /* wait for eh to begin */ + struct semaphore * eh_action; /* Wait for specific actions on the + host. */ + unsigned int eh_active:1; /* Indicates the eh thread is awake and active if + this is true. */ + struct wait_queue * host_wait; + Scsi_Host_Template * hostt; + atomic_t host_active; /* commands checked out */ + volatile unsigned short host_busy; /* commands actually active on low-level */ + volatile unsigned short host_failed; /* commands that failed. */ + +/* public: */ unsigned short extra_bytes; - volatile unsigned char host_busy; - char host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ + unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ unsigned long last_reset; - struct wait_queue *host_wait; - Scsi_Cmnd *host_queue; - Scsi_Host_Template * hostt; + /* * These three parameters can be used to allow for wide scsi, @@ -292,6 +355,8 @@ struct Scsi_Host int can_queue; short cmd_per_lun; short unsigned int sg_tablesize; + + unsigned in_recovery:1; unsigned unchecked_isa_dma:1; unsigned use_clustering:1; /* @@ -299,9 +364,20 @@ struct Scsi_Host */ unsigned loaded_as_module:1; + /* + * Host has rejected a command because it was busy. + */ + unsigned host_blocked:1; + void (*select_queue_depths)(struct Scsi_Host *, Scsi_Device *); - unsigned long hostdata[0]; /* Used for storage of host specific stuff */ + /* + * We should ensure that this is aligned, both for better performance + * and also because some compilers (m68k) don't automatically force + * alignment to a 4-byte boundary. + */ + unsigned long hostdata[0] /* Used for storage of host specific stuff */ + __attribute__ ((aligned (sizeof(unsigned long)))); }; extern struct Scsi_Host * scsi_hostlist; @@ -333,6 +409,8 @@ unsigned int scsi_init(void); extern struct Scsi_Host * scsi_register(Scsi_Host_Template *, int j); extern void scsi_unregister(struct Scsi_Host * i); +extern void scsi_mark_host_reset(struct Scsi_Host *Host); + #define BLANK_HOST {"", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} struct Scsi_Device_Template |