[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>

[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>
Boaz Harrosh · James Bottomley
1 parent 64a87b244b
Showing 7 changed files with 47 additions and 35 deletions Side-by-side Diff
block/scsi_ioctl.c
drivers/scsi/constants.c
drivers/scsi/scsi.c
drivers/scsi/scsi_lib.c
include/scsi/scsi.h
include/scsi/scsi_cmnd.h
include/scsi/scsi_host.h
@@ -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 @@
 	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]);
@@ -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);
@@ -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)
@@ -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
@@ -134,6 +128,38 @@
 /* Values for T10/04-262r7 */
 #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
@@ -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 */
@@ -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;
...	...	@@ -33,13 +33,12 @@
33	33	#include <scsi/scsi_cmnd.h>
34	34
35	35	/* Command group 3 is reserved and should never be used. */
36		-const unsigned char scsi_command_size[8] =
	36	+const unsigned char scsi_command_size_tbl[8] =
37	37	{
38	38	6, 10, 10, 12,
39	39	16, 12, 10, 10
40	40	};
41		-
42		-EXPORT_SYMBOL(scsi_command_size);
	41	+EXPORT_SYMBOL(scsi_command_size_tbl);
43	42
44	43	#include <scsi/sg.h>
45	44
...	...	@@ -28,7 +28,6 @@
28	28	#define SERVICE_ACTION_OUT_12 0xa9
29	29	#define SERVICE_ACTION_IN_16 0x9e
30	30	#define SERVICE_ACTION_OUT_16 0x9f
31		-#define VARIABLE_LENGTH_CMD 0x7f
32	31
33	32
34	33
...	...	@@ -210,7 +209,7 @@
210	209	cdb0 = cdbp[0];
211	210	switch(cdb0) {
212	211	case VARIABLE_LENGTH_CMD:
213		- len = cdbp[7] + 8;
	212	+ len = scsi_varlen_cdb_length(cdbp);
214	213	if (len < 10) {
215	214	printk("short variable length command, "
216	215	"len=%d ext_len=%d", len, cdb_len);
...	...	@@ -300,7 +299,7 @@
300	299	cdb0 = cdbp[0];
301	300	switch(cdb0) {
302	301	case VARIABLE_LENGTH_CMD:
303		- len = cdbp[7] + 8;
	302	+ len = scsi_varlen_cdb_length(cdbp);
304	303	if (len < 10) {
305	304	printk("short opcode=0x%x command, len=%d "
306	305	"ext_len=%d", cdb0, len, cdb_len);
...	...	@@ -335,10 +334,7 @@
335	334	int k, len;
336	335
337	336	print_opcode_name(cdb, 0);
338		- if (VARIABLE_LENGTH_CMD == cdb[0])
339		- len = cdb[7] + 8;
340		- else
341		- len = COMMAND_SIZE(cdb[0]);
	337	+ len = scsi_command_size(cdb);
342	338	/* print out all bytes in cdb */
343	339	for (k = 0; k < len; ++k)
344	340	printk(" %02x", cdb[k]);
...	...	@@ -79,15 +79,6 @@
79	79	#define MIN_RESET_PERIOD (15*HZ)
80	80
81	81	/*
82		- * Macro to determine the size of SCSI command. This macro takes vendor
83		- * unique commands into account. SCSI commands in groups 6 and 7 are
84		- * vendor unique and we will depend upon the command length being
85		- * supplied correctly in cmd_len.
86		- */
87		-#define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
88		- COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
89		-
90		-/*
91	82	* Note - the initial logging level can be set here to log events at boot time.
92	83	* After the system is up, you may enable logging via the /proc interface.
93	84	*/
94	85
...	...	@@ -709,9 +700,11 @@
709	700	* Before we queue this command, check if the command
710	701	* length exceeds what the host adapter can handle.
711	702	*/
712		- if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
	703	+ if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
713	704	SCSI_LOG_MLQUEUE(3,
714		- printk("queuecommand : command too long.\n"));
	705	+ printk("queuecommand : command too long. "
	706	+ "cdb_size=%d host->max_cmd_len=%d\n",
	707	+ cmd->cmd_len, cmd->device->host->max_cmd_len));
715	708	cmd->result = (DID_ABORT << 16);
716	709
717	710	scsi_done(cmd);
...	...	@@ -445,7 +445,7 @@
445	445	scsi_set_resid(cmd, 0);
446	446	memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
447	447	if (cmd->cmd_len == 0)
448		- cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]);
	448	+ cmd->cmd_len = scsi_command_size(cmd->cmnd);
449	449	}
450	450
451	451	void scsi_device_unbusy(struct scsi_device *sdev)
...	...	@@ -30,13 +30,6 @@
30	30	#endif
31	31
32	32	/*
33		- * SCSI command lengths
34		- */
35		-
36		-extern const unsigned char scsi_command_size[8];
37		-#define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
38		-
39		-/*
40	33	* Special value for scanning to specify scanning or rescanning of all
41	34	* possible channels, (target) ids, or luns on a given shost.
42	35	*/
...	...	@@ -109,6 +102,7 @@
109	102	#define MODE_SENSE_10 0x5a
110	103	#define PERSISTENT_RESERVE_IN 0x5e
111	104	#define PERSISTENT_RESERVE_OUT 0x5f
	105	+#define VARIABLE_LENGTH_CMD 0x7f
112	106	#define REPORT_LUNS 0xa0
113	107	#define MAINTENANCE_IN 0xa3
114	108	#define MOVE_MEDIUM 0xa5
...	...	@@ -134,6 +128,38 @@
134	128	/* Values for T10/04-262r7 */
135	129	#define ATA_16 0x85 /* 16-byte pass-thru */
136	130	#define ATA_12 0xa1 /* 12-byte pass-thru */
	131	+
	132	+/*
	133	+ * SCSI command lengths
	134	+ */
	135	+
	136	+#define SCSI_MAX_VARLEN_CDB_SIZE 260
	137	+
	138	+/* defined in T10 SCSI Primary Commands-2 (SPC2) */
	139	+struct scsi_varlen_cdb_hdr {
	140	+ u8 opcode; /* opcode always == VARIABLE_LENGTH_CMD */
	141	+ u8 control;
	142	+ u8 misc[5];
	143	+ u8 additional_cdb_length; /* total cdb length - 8 */
	144	+ __be16 service_action;
	145	+ /* service specific data follows */
	146	+};
	147	+
	148	+static inline unsigned
	149	+scsi_varlen_cdb_length(const void *hdr)
	150	+{
	151	+ return ((struct scsi_varlen_cdb_hdr *)hdr)->additional_cdb_length + 8;
	152	+}
	153	+
	154	+extern const unsigned char scsi_command_size_tbl[8];
	155	+#define COMMAND_SIZE(opcode) scsi_command_size_tbl[((opcode) >> 5) & 7]
	156	+
	157	+static inline unsigned
	158	+scsi_command_size(const unsigned char *cmnd)
	159	+{
	160	+ return (cmnd[0] == VARIABLE_LENGTH_CMD) ?
	161	+ scsi_varlen_cdb_length(cmnd) : COMMAND_SIZE(cmnd[0]);
	162	+}
137	163
138	164	/*
139	165	* SCSI Architecture Model (SAM) Status codes. Taken from SAM-3 draft
...	...	@@ -78,7 +78,7 @@
78	78	int allowed;
79	79	int timeout_per_command;
80	80
81		- unsigned char cmd_len;
	81	+ unsigned short cmd_len;
82	82	enum dma_data_direction sc_data_direction;
83	83
84	84	/* These elements define the operation we are about to perform */
...	...	@@ -573,13 +573,11 @@
573	573	/*
574	574	* The maximum length of SCSI commands that this host can accept.
575	575	* Probably 12 for most host adapters, but could be 16 for others.
	576	+ * or 260 if the driver supports variable length cdbs.
576	577	* For drivers that don't set this field, a value of 12 is
577		- * assumed. I am leaving this as a number rather than a bit
578		- * because you never know what subsequent SCSI standards might do
579		- * (i.e. could there be a 20 byte or a 24-byte command a few years
580		- * down the road?).
	578	+ * assumed.
581	579	*/
582		- unsigned char max_cmd_len;
	580	+ unsigned short max_cmd_len;
583	581
584	582	int this_id;
585	583	int can_queue;