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authorMartin K. Petersen <martin.petersen@oracle.com>2012-09-18 12:19:30 -0400
committerJames Bottomley <JBottomley@Parallels.com>2012-11-13 21:11:31 -0800
commit3c6bdaeab4fda6c9fdd5f3f5c610dea97bddf7d6 (patch)
tree85fad84ab7a257e1da2465711e6af8569934cf7c
parent49bd665c5407a453736d3232ee58f2906b42e83c (diff)
downloadlinux-linaro-stable-3c6bdaeab4fda6c9fdd5f3f5c610dea97bddf7d6.tar.gz
[SCSI] Add a report opcode helper
The REPORT SUPPORTED OPERATION CODES command can be used to query whether a given opcode is supported by a device. Add a helper function that allows us to look up commands. We only issue RSOC if the device reports compliance with SPC-3 or later. But to err on the side of caution we disable the command for ATA, FireWire and USB. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r--drivers/ata/libata-scsi.c1
-rw-r--r--drivers/firewire/sbp2.c1
-rw-r--r--drivers/scsi/scsi.c45
-rw-r--r--drivers/usb/storage/scsiglue.c3
-rw-r--r--include/scsi/scsi_device.h3
5 files changed, 53 insertions, 0 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index e3bda074fa12..7c2dead60518 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1052,6 +1052,7 @@ static void ata_scsi_sdev_config(struct scsi_device *sdev)
{
sdev->use_10_for_rw = 1;
sdev->use_10_for_ms = 1;
+ sdev->no_report_opcodes = 1;
/* Schedule policy is determined by ->qc_defer() callback and
* it needs to see every deferred qc. Set dev_blocked to 1 to
diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index 1162d6b3bf85..f82e9d4295d0 100644
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -1546,6 +1546,7 @@ static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
struct sbp2_logical_unit *lu = sdev->hostdata;
sdev->use_10_for_rw = 1;
+ sdev->no_report_opcodes = 1;
if (sbp2_param_exclusive_login)
sdev->manage_start_stop = 1;
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 2936b447cae9..2c0d0ec8150b 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -55,6 +55,7 @@
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/async.h>
+#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
@@ -1062,6 +1063,50 @@ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
/**
+ * scsi_report_opcode - Find out if a given command opcode is supported
+ * @sdev: scsi device to query
+ * @buffer: scratch buffer (must be at least 20 bytes long)
+ * @len: length of buffer
+ * @opcode: opcode for command to look up
+ *
+ * Uses the REPORT SUPPORTED OPERATION CODES to look up the given
+ * opcode. Returns 0 if RSOC fails or if the command opcode is
+ * unsupported. Returns 1 if the device claims to support the command.
+ */
+int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
+ unsigned int len, unsigned char opcode)
+{
+ unsigned char cmd[16];
+ struct scsi_sense_hdr sshdr;
+ int result;
+
+ if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
+ return 0;
+
+ memset(cmd, 0, 16);
+ cmd[0] = MAINTENANCE_IN;
+ cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
+ cmd[2] = 1; /* One command format */
+ cmd[3] = opcode;
+ put_unaligned_be32(len, &cmd[6]);
+ memset(buffer, 0, len);
+
+ result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
+ &sshdr, 30 * HZ, 3, NULL);
+
+ if (result && scsi_sense_valid(&sshdr) &&
+ sshdr.sense_key == ILLEGAL_REQUEST &&
+ (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
+ return 0;
+
+ if ((buffer[1] & 3) == 3) /* Command supported */
+ return 1;
+
+ return 0;
+}
+EXPORT_SYMBOL(scsi_report_opcode);
+
+/**
* scsi_device_get - get an additional reference to a scsi_device
* @sdev: device to get a reference to
*
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index a3d54366afcc..6ab376a7c501 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -186,6 +186,9 @@ static int slave_configure(struct scsi_device *sdev)
/* Some devices don't handle VPD pages correctly */
sdev->skip_vpd_pages = 1;
+ /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
+ sdev->no_report_opcodes = 1;
+
/* Some disks return the total number of blocks in response
* to READ CAPACITY rather than the highest block number.
* If this device makes that mistake, tell the sd driver. */
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 88fae8d20154..379d465e8070 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -135,6 +135,7 @@ struct scsi_device {
* because we did a bus reset. */
unsigned use_10_for_rw:1; /* first try 10-byte read / write */
unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */
+ unsigned no_report_opcodes:1; /* no REPORT SUPPORTED OPERATION CODES */
unsigned skip_ms_page_8:1; /* do not use MODE SENSE page 0x08 */
unsigned skip_ms_page_3f:1; /* do not use MODE SENSE page 0x3f */
unsigned skip_vpd_pages:1; /* do not read VPD pages */
@@ -362,6 +363,8 @@ extern int scsi_test_unit_ready(struct scsi_device *sdev, int timeout,
int retries, struct scsi_sense_hdr *sshdr);
extern int scsi_get_vpd_page(struct scsi_device *, u8 page, unsigned char *buf,
int buf_len);
+extern int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
+ unsigned int len, unsigned char opcode);
extern int scsi_device_set_state(struct scsi_device *sdev,
enum scsi_device_state state);
extern struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,