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[SCSI] add support for variable length extended commands

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Add support for variable-length, extended, and vendor specific
CDBs to scsi-ml. It is now possible for initiators and ULD's
to issue these types of commands. LLDs need not change much.
All they need is to raise the .max_cmd_len to the longest command
they support (see iscsi patch).

- clean-up some code paths that did not expect commands to be
  larger than 16, and change cmd_len members' type to short as
  char is not enough.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Boaz Harrosh
2008-04-30 11:27:26 +03:00
committed by James Bottomley
parent 64a87b244b
commit db4742dd8f
7 changed files with 47 additions and 35 deletions
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40
include/scsi/scsi.h
View File

@@ -29,13 +29,6 @@
#define SCSI_MAX_SG_CHAIN_SEGMENTS SCSI_MAX_SG_SEGMENTS
#endif
/*
* SCSI command lengths
*/
extern const unsigned char scsi_command_size[8];
#define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
/*
* Special value for scanning to specify scanning or rescanning of all
* possible channels, (target) ids, or luns on a given shost.
@@ -109,6 +102,7 @@ extern const unsigned char scsi_command_size[8];
#define MODE_SENSE_10 0x5a
#define PERSISTENT_RESERVE_IN 0x5e
#define PERSISTENT_RESERVE_OUT 0x5f
#define VARIABLE_LENGTH_CMD 0x7f
#define REPORT_LUNS 0xa0
#define MAINTENANCE_IN 0xa3
#define MOVE_MEDIUM 0xa5
@@ -135,6 +129,38 @@ extern const unsigned char scsi_command_size[8];
#define ATA_16 0x85 /* 16-byte pass-thru */
#define ATA_12 0xa1 /* 12-byte pass-thru */
/*
* SCSI command lengths
*/
#define SCSI_MAX_VARLEN_CDB_SIZE 260
/* defined in T10 SCSI Primary Commands-2 (SPC2) */
struct scsi_varlen_cdb_hdr {
u8 opcode; /* opcode always == VARIABLE_LENGTH_CMD */
u8 control;
u8 misc[5];
u8 additional_cdb_length; /* total cdb length - 8 */
__be16 service_action;
/* service specific data follows */
};
static inline unsigned
scsi_varlen_cdb_length(const void *hdr)
{
return ((struct scsi_varlen_cdb_hdr *)hdr)->additional_cdb_length + 8;
}
extern const unsigned char scsi_command_size_tbl[8];
#define COMMAND_SIZE(opcode) scsi_command_size_tbl[((opcode) >> 5) & 7]
static inline unsigned
scsi_command_size(const unsigned char *cmnd)
{
return (cmnd[0] == VARIABLE_LENGTH_CMD) ?
scsi_varlen_cdb_length(cmnd) : COMMAND_SIZE(cmnd[0]);
}
/*
* SCSI Architecture Model (SAM) Status codes. Taken from SAM-3 draft
* T10/1561-D Revision 4 Draft dated 7th November 2002.

2
include/scsi/scsi_cmnd.h
View File

@@ -78,7 +78,7 @@ struct scsi_cmnd {
int allowed;
int timeout_per_command;
unsigned char cmd_len;
unsigned short cmd_len;
enum dma_data_direction sc_data_direction;
/* These elements define the operation we are about to perform */

8
include/scsi/scsi_host.h
View File

@@ -573,13 +573,11 @@ struct Scsi_Host {
/*
* The maximum length of SCSI commands that this host can accept.
* Probably 12 for most host adapters, but could be 16 for others.
* or 260 if the driver supports variable length cdbs.
* For drivers that don't set this field, a value of 12 is
* assumed. I am leaving this as a number rather than a bit
* because you never know what subsequent SCSI standards might do
* (i.e. could there be a 20 byte or a 24-byte command a few years
* down the road?).
* assumed.
*/
unsigned char max_cmd_len;
unsigned short max_cmd_len;
int this_id;
int can_queue;