alistair23-linux/include/scsi/scsi_eh.h
Boaz Harrosh 64a87b244b [SCSI] Let scsi_cmnd->cmnd use request->cmd buffer
- struct scsi_cmnd had a 16 bytes command buffer of its own.
   This is an unnecessary duplication and copy of request's
   cmd. It is probably left overs from the time that scsi_cmnd
   could function without a request attached. So clean that up.

 - Once above is done, few places, apart from scsi-ml, needed
   adjustments due to changing the data type of scsi_cmnd->cmnd.

 - Lots of drivers still use MAX_COMMAND_SIZE. So I have left
   that #define but equate it to BLK_MAX_CDB. The way I see it
   and is reflected in the patch below is.
   MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
                      as per the SCSI standard and is not related
                      to the implementation.
   BLK_MAX_CDB.     - The allocated space at the request level

 - I have audit all ISA drivers and made sure none use ->cmnd in a DMA
   Operation. Same audit was done by Andi Kleen.

(*)fixed-length here means commands that their size can be determined
   by their opcode and the CDB does not carry a length specifier, (unlike
   the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
   true and the SCSI standard also defines extended commands and
   vendor specific commands that can be bigger than 16 bytes. The kernel
   will support these using the same infrastructure used for VARLEN CDB's.
   So in effect MAX_COMMAND_SIZE means the maximum size command
   scsi-ml supports without specifying a cmd_len by ULD's

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-05-02 10:18:22 -05:00

94 lines
2.7 KiB
C

#ifndef _SCSI_SCSI_EH_H
#define _SCSI_SCSI_EH_H
#include <linux/scatterlist.h>
#include <scsi/scsi_cmnd.h>
struct scsi_device;
struct Scsi_Host;
/*
* This is a slightly modified SCSI sense "descriptor" format header.
* The addition is to allow the 0x70 and 0x71 response codes. The idea
* is to place the salient data from either "fixed" or "descriptor" sense
* format into one structure to ease application processing.
*
* The original sense buffer should be kept around for those cases
* in which more information is required (e.g. the LBA of a MEDIUM ERROR).
*/
struct scsi_sense_hdr { /* See SPC-3 section 4.5 */
u8 response_code; /* permit: 0x0, 0x70, 0x71, 0x72, 0x73 */
u8 sense_key;
u8 asc;
u8 ascq;
u8 byte4;
u8 byte5;
u8 byte6;
u8 additional_length; /* always 0 for fixed sense format */
};
static inline int scsi_sense_valid(struct scsi_sense_hdr *sshdr)
{
if (!sshdr)
return 0;
return (sshdr->response_code & 0x70) == 0x70;
}
extern void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
struct list_head *done_q);
extern void scsi_eh_flush_done_q(struct list_head *done_q);
extern void scsi_report_bus_reset(struct Scsi_Host *, int);
extern void scsi_report_device_reset(struct Scsi_Host *, int, int);
extern int scsi_block_when_processing_errors(struct scsi_device *);
extern int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
struct scsi_sense_hdr *sshdr);
extern int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
struct scsi_sense_hdr *sshdr);
static inline int scsi_sense_is_deferred(struct scsi_sense_hdr *sshdr)
{
return ((sshdr->response_code >= 0x70) && (sshdr->response_code & 1));
}
extern const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
int desc_type);
extern int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
u64 * info_out);
extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
/*
* Reset request from external source
*/
#define SCSI_TRY_RESET_DEVICE 1
#define SCSI_TRY_RESET_BUS 2
#define SCSI_TRY_RESET_HOST 3
#define SCSI_TRY_RESET_TARGET 4
extern int scsi_reset_provider(struct scsi_device *, int);
struct scsi_eh_save {
/* saved state */
int result;
enum dma_data_direction data_direction;
unsigned char cmd_len;
unsigned char *cmnd;
struct scsi_data_buffer sdb;
struct request *next_rq;
/* new command support */
unsigned char eh_cmnd[BLK_MAX_CDB];
struct scatterlist sense_sgl;
};
extern void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd,
struct scsi_eh_save *ses, unsigned char *cmnd,
int cmnd_size, unsigned sense_bytes);
extern void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd,
struct scsi_eh_save *ses);
#endif /* _SCSI_SCSI_EH_H */