linux/include/scsi/scsi_cmnd.h

166 lines
5.5 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;
unsigned short state;
unsigned short owner;
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_state; /* Used for state tracking in error handlr */
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 when internal_cmnd
* passes it to the driver's queue command function. The serial_number
* is cleared when scsi_done is entered indicating that the command has
* been completed. If a timeout occurs, the serial number at the moment
* of timeout is copied into serial_number_at_timeout. By subsequently
* comparing the serial_number and serial_number_at_timeout fields
* during abort or reset processing, we can detect whether the command
* has already completed. This also detects cases where the command has
* completed and the SCSI Command structure has already being reused
* for another command, so that we can avoid incorrectly aborting or
* resetting the new command.
* The serial number is only unique per host.
*/
unsigned long serial_number;
unsigned long serial_number_at_timeout;
int retries;
int allowed;
int timeout_per_command;
int timeout_total;
int timeout;
/*
* We handle the timeout differently if it happens when a reset,
* abort, etc are in process.
*/
unsigned volatile char internal_timeout;
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 short abort_reason; /* If the mid-level code requests an
* abort, this is the reason. */
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 */