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

[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

block/scsi_ioctl.c

+2 −3
Original line number Diff line number Diff line
@@ -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>

drivers/scsi/constants.c

+3 −7
Original line number Diff line number Diff line
@@ -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]);

drivers/scsi/scsi.c

+4 −11
Original line number Diff line number Diff line
@@ -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);

drivers/scsi/scsi_lib.c

+1 −1
Original line number Diff line number Diff line
@@ -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)

include/scsi/scsi.h

+33 −7
Original line number Diff line number Diff line
@@ -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.

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