Commit db4742dd authored by Boaz Harrosh's avatar Boaz Harrosh Committed by James Bottomley

[SCSI] add support for variable length extended commands

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: default avatarBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: default avatarBenny Halevy <bhalevy@panasas.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 64a87b24
......@@ -33,13 +33,12 @@
#include <scsi/scsi_cmnd.h>
/* Command group 3 is reserved and should never be used. */
const unsigned char scsi_command_size[8] =
const unsigned char scsi_command_size_tbl[8] =
{
6, 10, 10, 12,
16, 12, 10, 10
};
EXPORT_SYMBOL(scsi_command_size);
EXPORT_SYMBOL(scsi_command_size_tbl);
#include <scsi/sg.h>
......
......@@ -28,7 +28,6 @@
#define SERVICE_ACTION_OUT_12 0xa9
#define SERVICE_ACTION_IN_16 0x9e
#define SERVICE_ACTION_OUT_16 0x9f
#define VARIABLE_LENGTH_CMD 0x7f
......@@ -210,7 +209,7 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
cdb0 = cdbp[0];
switch(cdb0) {
case VARIABLE_LENGTH_CMD:
len = cdbp[7] + 8;
len = scsi_varlen_cdb_length(cdbp);
if (len < 10) {
printk("short variable length command, "
"len=%d ext_len=%d", len, cdb_len);
......@@ -300,7 +299,7 @@ static void print_opcode_name(unsigned char * cdbp, int cdb_len)
cdb0 = cdbp[0];
switch(cdb0) {
case VARIABLE_LENGTH_CMD:
len = cdbp[7] + 8;
len = scsi_varlen_cdb_length(cdbp);
if (len < 10) {
printk("short opcode=0x%x command, len=%d "
"ext_len=%d", cdb0, len, cdb_len);
......@@ -335,10 +334,7 @@ void __scsi_print_command(unsigned char *cdb)
int k, len;
print_opcode_name(cdb, 0);
if (VARIABLE_LENGTH_CMD == cdb[0])
len = cdb[7] + 8;
else
len = COMMAND_SIZE(cdb[0]);
len = scsi_command_size(cdb);
/* print out all bytes in cdb */
for (k = 0; k < len; ++k)
printk(" %02x", cdb[k]);
......
......@@ -78,15 +78,6 @@ static void scsi_done(struct scsi_cmnd *cmd);
/* Do not call reset on error if we just did a reset within 15 sec. */
#define MIN_RESET_PERIOD (15*HZ)
/*
* Macro to determine the size of SCSI command. This macro takes vendor
* unique commands into account. SCSI commands in groups 6 and 7 are
* vendor unique and we will depend upon the command length being
* supplied correctly in cmd_len.
*/
#define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
/*
* Note - the initial logging level can be set here to log events at boot time.
* After the system is up, you may enable logging via the /proc interface.
......@@ -709,9 +700,11 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
* Before we queue this command, check if the command
* length exceeds what the host adapter can handle.
*/
if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
SCSI_LOG_MLQUEUE(3,
printk("queuecommand : command too long.\n"));
printk("queuecommand : command too long. "
"cdb_size=%d host->max_cmd_len=%d\n",
cmd->cmd_len, cmd->device->host->max_cmd_len));
cmd->result = (DID_ABORT << 16);
scsi_done(cmd);
......
......@@ -445,7 +445,7 @@ static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
scsi_set_resid(cmd, 0);
memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
if (cmd->cmd_len == 0)
cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
cmd->cmd_len = scsi_command_size(cmd->cmnd);
}
void scsi_device_unbusy(struct scsi_device *sdev)
......
......@@ -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.
......
......@@ -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 */
......
......@@ -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;
......
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