From 3c6bdaeab4fda6c9fdd5f3f5c610dea97bddf7d6 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 18 Sep 2012 12:19:30 -0400 Subject: [PATCH] [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 Acked-by: Mike Snitzer Signed-off-by: James Bottomley --- drivers/ata/libata-scsi.c | 1 + drivers/firewire/sbp2.c | 1 + drivers/scsi/scsi.c | 45 ++++++++++++++++++++++++++++++++++++++++++ drivers/usb/storage/scsiglue.c | 3 +++ include/scsi/scsi_device.h | 3 +++ 5 files changed, 53 insertions(+) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index e3bda07..7c2dead 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 1162d6b..f82e9d4 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 2936b44..2c0d0ec 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include @@ -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 a3d5436..6ab376a 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 88fae8d..379d465 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, -- 1.7.12