mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
b21a413851
There are certain rogue devices (and the aic7xxx driver) that return BUSY or QUEUE_FULL forever. This code will apply a global timeout (of the total number of retries times the per command timer) to a given command. If it is exceeded, the command is completed regardless of its state. The patch also removes the unused field in the command: timeout and timeout_total. This solves the problem of detecting an endless loop in the mid-layer because of BUSY/QUEUE_FULL bouncing, but will not recover the device. In the aic7xxx case, the driver can be recovered by sending a bus reset, so possibly this should be tied into the error handler? Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
154 lines
5 KiB
C
154 lines
5 KiB
C
#ifndef _SCSI_SCSI_CMND_H
|
|
#define _SCSI_SCSI_CMND_H
|
|
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/list.h>
|
|
#include <linux/types.h>
|
|
|
|
struct request;
|
|
struct scatterlist;
|
|
struct scsi_device;
|
|
struct scsi_request;
|
|
|
|
|
|
/* embedded in scsi_cmnd */
|
|
struct scsi_pointer {
|
|
char *ptr; /* data pointer */
|
|
int this_residual; /* left in this buffer */
|
|
struct scatterlist *buffer; /* which buffer */
|
|
int buffers_residual; /* how many buffers left */
|
|
|
|
dma_addr_t dma_handle;
|
|
|
|
volatile int Status;
|
|
volatile int Message;
|
|
volatile int have_data_in;
|
|
volatile int sent_command;
|
|
volatile int phase;
|
|
};
|
|
|
|
struct scsi_cmnd {
|
|
int sc_magic;
|
|
|
|
struct scsi_device *device;
|
|
struct scsi_request *sc_request;
|
|
|
|
struct list_head list; /* scsi_cmnd participates in queue lists */
|
|
|
|
struct list_head eh_entry; /* entry for the host eh_cmd_q */
|
|
int eh_eflags; /* Used by error handlr */
|
|
void (*done) (struct scsi_cmnd *); /* Mid-level done function */
|
|
|
|
/*
|
|
* A SCSI Command is assigned a nonzero serial_number before passed
|
|
* to the driver's queue command function. The serial_number is
|
|
* cleared when scsi_done is entered indicating that the command
|
|
* has been completed. It currently doesn't have much use other
|
|
* than printk's. Some lldd's use this number for other purposes.
|
|
* It's almost certain that such usages are either incorrect or
|
|
* meaningless. Please kill all usages other than printk's. Also,
|
|
* as this number is always identical to ->pid, please convert
|
|
* printk's to use ->pid, so that we can kill this field.
|
|
*/
|
|
unsigned long serial_number;
|
|
/*
|
|
* This is set to jiffies as it was when the command was first
|
|
* allocated. It is used to time how long the command has
|
|
* been outstanding
|
|
*/
|
|
unsigned long jiffies_at_alloc;
|
|
|
|
int retries;
|
|
int allowed;
|
|
int timeout_per_command;
|
|
|
|
unsigned char cmd_len;
|
|
unsigned char old_cmd_len;
|
|
enum dma_data_direction sc_data_direction;
|
|
enum dma_data_direction sc_old_data_direction;
|
|
|
|
/* These elements define the operation we are about to perform */
|
|
#define MAX_COMMAND_SIZE 16
|
|
unsigned char cmnd[MAX_COMMAND_SIZE];
|
|
unsigned request_bufflen; /* Actual request size */
|
|
|
|
struct timer_list eh_timeout; /* Used to time out the command. */
|
|
void *request_buffer; /* Actual requested buffer */
|
|
|
|
/* These elements define the operation we ultimately want to perform */
|
|
unsigned char data_cmnd[MAX_COMMAND_SIZE];
|
|
unsigned short old_use_sg; /* We save use_sg here when requesting
|
|
* sense info */
|
|
unsigned short use_sg; /* Number of pieces of scatter-gather */
|
|
unsigned short sglist_len; /* size of malloc'd scatter-gather list */
|
|
unsigned bufflen; /* Size of data buffer */
|
|
void *buffer; /* Data buffer */
|
|
|
|
unsigned underflow; /* Return error if less than
|
|
this amount is transferred */
|
|
unsigned old_underflow; /* save underflow here when reusing the
|
|
* command for error handling */
|
|
|
|
unsigned transfersize; /* How much we are guaranteed to
|
|
transfer with each SCSI transfer
|
|
(ie, between disconnect /
|
|
reconnects. Probably == sector
|
|
size */
|
|
|
|
int resid; /* Number of bytes requested to be
|
|
transferred less actual number
|
|
transferred (0 if not supported) */
|
|
|
|
struct request *request; /* The command we are
|
|
working on */
|
|
|
|
#define SCSI_SENSE_BUFFERSIZE 96
|
|
unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE]; /* obtained by REQUEST SENSE
|
|
* when CHECK CONDITION is
|
|
* received on original command
|
|
* (auto-sense) */
|
|
|
|
/* Low-level done function - can be used by low-level driver to point
|
|
* to completion function. Not used by mid/upper level code. */
|
|
void (*scsi_done) (struct scsi_cmnd *);
|
|
|
|
/*
|
|
* The following fields can be written to by the host specific code.
|
|
* Everything else should be left alone.
|
|
*/
|
|
struct scsi_pointer SCp; /* Scratchpad used by some host adapters */
|
|
|
|
unsigned char *host_scribble; /* The host adapter is allowed to
|
|
* call scsi_malloc and get some memory
|
|
* and hang it here. The host adapter
|
|
* is also expected to call scsi_free
|
|
* to release this memory. (The memory
|
|
* obtained by scsi_malloc is guaranteed
|
|
* to be at an address < 16Mb). */
|
|
|
|
int result; /* Status code from lower level driver */
|
|
|
|
unsigned char tag; /* SCSI-II queued command tag */
|
|
unsigned long pid; /* Process ID, starts at 0. Unique per host. */
|
|
};
|
|
|
|
/*
|
|
* These are the values that scsi_cmd->state can take.
|
|
*/
|
|
#define SCSI_STATE_TIMEOUT 0x1000
|
|
#define SCSI_STATE_FINISHED 0x1001
|
|
#define SCSI_STATE_FAILED 0x1002
|
|
#define SCSI_STATE_QUEUED 0x1003
|
|
#define SCSI_STATE_UNUSED 0x1006
|
|
#define SCSI_STATE_DISCONNECTING 0x1008
|
|
#define SCSI_STATE_INITIALIZING 0x1009
|
|
#define SCSI_STATE_BHQUEUE 0x100a
|
|
#define SCSI_STATE_MLQUEUE 0x100b
|
|
|
|
|
|
extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
|
|
extern void scsi_put_command(struct scsi_cmnd *);
|
|
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
|
|
extern void scsi_finish_command(struct scsi_cmnd *cmd);
|
|
|
|
#endif /* _SCSI_SCSI_CMND_H */
|