[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: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index a2c3a93..aaf07e4 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -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>
diff --git a/drivers/scsi/constants.c b/drivers/scsi/constants.c
index 403a7f2..9785d73 100644
--- a/drivers/scsi/constants.c
+++ b/drivers/scsi/constants.c
@@ -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 @@
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 @@
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 @@
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]);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 749c9c7..110e776 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -79,15 +79,6 @@
#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 @@
* 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);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 325270b..ba7e8ad 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -445,7 +445,7 @@
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)
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 1f74bcd..32742c4 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -30,13 +30,6 @@
#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 @@
#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
@@ -136,6 +130,38 @@
#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.
*/
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 7ed883c8..3e46dfa 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -78,7 +78,7 @@
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 */
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index d967d6d..1834fdf 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -573,13 +573,11 @@
/*
* 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;
