Support for controllers and disks that implement DIF protection
information:
- During command preparation the RDPROTECT/WRPROTECT must be set
correctly if the target has DIF enabled.
- READ(6) and WRITE(6) are not supported when DIF is on.
- The controller must be told how to handle the I/O via the
protection operation field in scsi_cmnd.
- sd_dif.c implements the functions required to prepare and complete
requests with protection information attached.
- Refactor the I/O completion code that extracts the failed LBA.
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
5 files changed, 642 insertions(+), 40 deletions(-)
drivers/scsi/Kconfig | 1
drivers/scsi/Makefile | 2
drivers/scsi/sd.c | 121 +++++++----
drivers/scsi/sd.h | 25 ++
drivers/scsi/sd_dif.c | 533 +++++++++++++++++++++++++++++++++++++++++++++++++
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -63,6 +63,7 @@ config BLK_DEV_SD
config BLK_DEV_SD
tristate "SCSI disk support"
depends on SCSI
+ select CRC_T10DIF
---help---
If you want to use SCSI hard disks, Fibre Channel disks,
Serial ATA (SATA) or Parallel ATA (PATA) hard disks,
diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -149,6 +149,8 @@ scsi_tgt-y += scsi_tgt_lib.o scsi_tgt_
scsi_tgt-y += scsi_tgt_lib.o scsi_tgt_if.o
sd_mod-objs := sd.o
+sd_mod-$(CONFIG_BLK_DEV_INTEGRITY) += sd_dif.o
+
sr_mod-objs := sr.o sr_ioctl.o sr_vendor.o
ncr53c8xx-flags-$(CONFIG_SCSI_ZALON) \
:= -DCONFIG_NCR53C8XX_PREFETCH -DSCSI_NCR_BIG_ENDIAN \
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -374,6 +374,7 @@ static int sd_prep_fn(struct request_que
struct scsi_cmnd *SCpnt;
struct scsi_device *sdp = q->queuedata;
struct gendisk *disk = rq->rq_disk;
+ struct scsi_disk *sdkp;
sector_t block = rq->sector;
unsigned int this_count = rq->nr_sectors;
unsigned int timeout = sdp->timeout;
@@ -390,6 +391,7 @@ static int sd_prep_fn(struct request_que
if (ret != BLKPREP_OK)
goto out;
SCpnt = rq->special;
+ sdkp = scsi_disk(disk);
/* from here on until we're complete, any goto out
* is used for a killable error condition */
@@ -479,6 +481,11 @@ static int sd_prep_fn(struct request_que
}
SCpnt->cmnd[0] = WRITE_6;
SCpnt->sc_data_direction = DMA_TO_DEVICE;
+
+ if (blk_integrity_rq(rq) &&
+ sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
+ goto out;
+
} else if (rq_data_dir(rq) == READ) {
SCpnt->cmnd[0] = READ_6;
SCpnt->sc_data_direction = DMA_FROM_DEVICE;
@@ -493,8 +500,12 @@ static int sd_prep_fn(struct request_que
"writing" : "reading", this_count,
rq->nr_sectors));
- SCpnt->cmnd[1] = 0;
-
+ /* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
+ if (scsi_host_dif_capable(sdp->host, sdkp->protection_type))
+ SCpnt->cmnd[1] = 1 << 5;
+ else
+ SCpnt->cmnd[1] = 0;
+
if (block > 0xffffffff) {
SCpnt->cmnd[0] += READ_16 - READ_6;
SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;
@@ -512,6 +523,7 @@ static int sd_prep_fn(struct request_que
SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
} else if ((this_count > 0xff) || (block > 0x1fffff) ||
+ scsi_device_protection(SCpnt->device) ||
SCpnt->device->use_10_for_rw) {
if (this_count > 0xffff)
this_count = 0xffff;
@@ -545,6 +557,10 @@ static int sd_prep_fn(struct request_que
SCpnt->cmnd[5] = 0;
}
SCpnt->sdb.length = this_count * sdp->sector_size;
+
+ /* If DIF or DIX is enabled, tell HBA how to handle request */
+ if (sdkp->protection_type || scsi_prot_sg_count(SCpnt))
+ sd_dif_op(SCpnt, sdkp->protection_type, scsi_prot_sg_count(SCpnt));
/*
* We shouldn't disconnect in the middle of a sector, so with a dumb
@@ -940,6 +956,48 @@ static struct block_device_operations sd
.revalidate_disk = sd_revalidate_disk,
};
+static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
+{
+ u64 start_lba = scmd->request->sector;
+ u64 end_lba = scmd->request->sector + (scsi_bufflen(scmd) / 512);
+ u64 bad_lba;
+ int info_valid;
+
+ if (!blk_fs_request(scmd->request))
+ return 0;
+
+ info_valid = scsi_get_sense_info_fld(scmd->sense_buffer,
+ SCSI_SENSE_BUFFERSIZE,
+ &bad_lba);
+ if (!info_valid)
+ return 0;
+
+ if (scsi_bufflen(scmd) <= scmd->device->sector_size)
+ return 0;
+
+ if (scmd->device->sector_size < 512) {
+ /* only legitimate sector_size here is 256 */
+ start_lba <<= 1;
+ end_lba <<= 1;
+ } else {
+ /* be careful ... don't want any overflows */
+ u64 factor = scmd->device->sector_size / 512;
+ do_div(start_lba, factor);
+ do_div(end_lba, factor);
+ }
+
+ /* The bad lba was reported incorrectly, we have no idea where
+ * the error is.
+ */
+ if (bad_lba < start_lba || bad_lba >= end_lba)
+ return 0;
+
+ /* This computation should always be done in terms of
+ * the resolution of the device's medium.
+ */
+ return (bad_lba - start_lba) * scmd->device->sector_size;
+}
+
/**
* sd_done - bottom half handler: called when the lower level
* driver has completed (successfully or otherwise) a scsi command.
@@ -950,15 +1008,10 @@ static int sd_done(struct scsi_cmnd *SCp
static int sd_done(struct scsi_cmnd *SCpnt)
{
int result = SCpnt->result;
- unsigned int xfer_size = scsi_bufflen(SCpnt);
- unsigned int good_bytes = result ? 0 : xfer_size;
- u64 start_lba = SCpnt->request->sector;
- u64 end_lba = SCpnt->request->sector + (xfer_size / 512);
- u64 bad_lba;
+ unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
int sense_deferred = 0;
- int info_valid;
if (result) {
sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);
@@ -983,36 +1036,7 @@ static int sd_done(struct scsi_cmnd *SCp
switch (sshdr.sense_key) {
case HARDWARE_ERROR:
case MEDIUM_ERROR:
- if (!blk_fs_request(SCpnt->request))
- goto out;
- info_valid = scsi_get_sense_info_fld(SCpnt->sense_buffer,
- SCSI_SENSE_BUFFERSIZE,
- &bad_lba);
- if (!info_valid)
- goto out;
- if (xfer_size <= SCpnt->device->sector_size)
- goto out;
- if (SCpnt->device->sector_size < 512) {
- /* only legitimate sector_size here is 256 */
- start_lba <<= 1;
- end_lba <<= 1;
- } else {
- /* be careful ... don't want any overflows */
- u64 factor = SCpnt->device->sector_size / 512;
- do_div(start_lba, factor);
- do_div(end_lba, factor);
- }
-
- if (bad_lba < start_lba || bad_lba >= end_lba)
- /* the bad lba was reported incorrectly, we have
- * no idea where the error is
- */
- goto out;
-
- /* This computation should always be done in terms of
- * the resolution of the device's medium.
- */
- good_bytes = (bad_lba - start_lba)*SCpnt->device->sector_size;
+ good_bytes = sd_completed_bytes(SCpnt);
break;
case RECOVERED_ERROR:
case NO_SENSE:
@@ -1022,10 +1046,23 @@ static int sd_done(struct scsi_cmnd *SCp
scsi_print_sense("sd", SCpnt);
SCpnt->result = 0;
memset(SCpnt->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
- good_bytes = xfer_size;
+ good_bytes = scsi_bufflen(SCpnt);
+ break;
+ case ABORTED_COMMAND:
+ if (sshdr.asc == 0x10) { /* DIF: Disk detected corruption */
+ scsi_print_result(SCpnt);
+ scsi_print_sense("sd", SCpnt);
+ good_bytes = sd_completed_bytes(SCpnt);
+ }
break;
case ILLEGAL_REQUEST:
- if (SCpnt->device->use_10_for_rw &&
+ if (sshdr.asc == 0x10) { /* DIX: HBA detected corruption */
+ scsi_print_result(SCpnt);
+ scsi_print_sense("sd", SCpnt);
+ return 0;
+ }
+ if (!scsi_device_protection(SCpnt->device) &&
+ SCpnt->device->use_10_for_rw &&
(SCpnt->cmnd[0] == READ_10 ||
SCpnt->cmnd[0] == WRITE_10))
SCpnt->device->use_10_for_rw = 0;
@@ -1038,6 +1075,9 @@ static int sd_done(struct scsi_cmnd *SCp
break;
}
out:
+ if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
+ sd_dif_complete(SCpnt, good_bytes);
+
return good_bytes;
}
@@ -1823,6 +1863,7 @@ static int sd_probe(struct device *dev)
dev_set_drvdata(dev, sdkp);
add_disk(gd);
+ sd_dif_config_host(sdkp);
sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
sdp->removable ? "removable " : "");
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -82,4 +82,29 @@ enum sd_dif_target_protection_types {
SD_DIF_TYPE3_PROTECTION = 0x3,
};
+/*
+ * Data Integrity Field tuple.
+ */
+struct sd_dif_tuple {
+ __be16 guard_tag; /* Checksum */
+ __be16 app_tag; /* Opaque storage */
+ __be32 ref_tag; /* Target LBA or indirect LBA */
+};
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+extern void sd_dif_op(struct scsi_cmnd *, unsigned int, unsigned int);
+extern void sd_dif_config_host(struct scsi_disk *);
+extern int sd_dif_prepare(struct request *rq, sector_t, unsigned int);
+extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+
+#define sd_dif_op(a, b, c) do { } while (0)
+#define sd_dif_config_host(a) do { } while (0)
+#define sd_dif_prepare(a, b, c) (0)
+#define sd_dif_complete(a, b) (0)
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
#endif /* _SCSI_DISK_H */
diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
new file mode 100644
--- /dev/null
+++ b/drivers/scsi/sd_dif.c
@@ -0,0 +1,533 @@
+/*
+ * sd_dif.c - SCSI Data Integrity Field
+ *
+ * Copyright (C) 2007, 2008 Oracle Corporation
+ * Written by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/blkdev.h>
+#include <linux/crc-t10dif.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/scsicam.h>
+
+#include <net/checksum.h>
+
+#include "sd.h"
+
+typedef __u16 (csum_fn) (void *, unsigned int);
+
+static __u16 sd_dif_crc_fn(void *data, unsigned int len)
+{
+ return cpu_to_be16(crc_t10dif(data, len));
+}
+
+static __u16 sd_dif_ip_fn(void *data, unsigned int len)
+{
+ return ip_compute_csum(data, len);
+}
+
+/*
+ * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
+ * 16 bit app tag, 32 bit reference tag.
+ */
+static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
+{
+ void *buf = bix->data_buf;
+ struct sd_dif_tuple *sdt = bix->prot_buf;
+ sector_t sector = bix->sector;
+ unsigned int i;
+
+ for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
+ sdt->guard_tag = fn(buf, bix->sector_size);
+ sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
+ sdt->app_tag = 0;
+
+ buf += bix->sector_size;
+ sector++;
+ }
+}
+
+static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix)
+{
+ sd_dif_type1_generate(bix, sd_dif_crc_fn);
+}
+
+static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix)
+{
+ sd_dif_type1_generate(bix, sd_dif_ip_fn);
+}
+
+static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
+{
+ void *buf = bix->data_buf;
+ struct sd_dif_tuple *sdt = bix->prot_buf;
+ sector_t sector = bix->sector;
+ unsigned int i;
+ __u16 csum;
+
+ for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
+ /* Unwritten sectors */
+ if (sdt->app_tag == 0xffff)
+ return 0;
+
+ /* Bad ref tag received from disk */
+ if (sdt->ref_tag == 0xffffffff) {
+ printk(KERN_ERR
+ "%s: bad phys ref tag on sector %lu\n",
+ bix->disk_name, (unsigned long)sector);
+ return -EIO;
+ }
+
+ if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
+ printk(KERN_ERR
+ "%s: ref tag error on sector %lu (rcvd %u)\n",
+ bix->disk_name, (unsigned long)sector,
+ be32_to_cpu(sdt->ref_tag));
+ return -EIO;
+ }
+
+ csum = fn(buf, bix->sector_size);
+
+ if (sdt->guard_tag != csum) {
+ printk(KERN_ERR "%s: guard tag error on sector %lu " \
+ "(rcvd %04x, data %04x)\n", bix->disk_name,
+ (unsigned long)sector,
+ be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
+ return -EIO;
+ }
+
+ buf += bix->sector_size;
+ sector++;
+ }
+
+ return 0;
+}
+
+static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
+{
+ return sd_dif_type1_verify(bix, sd_dif_crc_fn);
+}
+
+static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
+{
+ return sd_dif_type1_verify(bix, sd_dif_ip_fn);
+}
+
+/*
+ * Functions for interleaving and deinterleaving application tags
+ */
+static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors)
+{
+ struct sd_dif_tuple *sdt = prot;
+ char *tag = tag_buf;
+ unsigned int i, j;
+
+ for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
+ sdt->app_tag = tag[j] << 8 | tag[j+1];
+ BUG_ON(sdt->app_tag == 0xffff);
+ }
+}
+
+static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors)
+{
+ struct sd_dif_tuple *sdt = prot;
+ char *tag = tag_buf;
+ unsigned int i, j;
+
+ for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
+ tag[j] = (sdt->app_tag & 0xff00) >> 8;
+ tag[j+1] = sdt->app_tag & 0xff;
+ }
+}
+
+static struct blk_integrity dif_type1_integrity_crc = {
+ .name = "T10-DIF-TYPE1-CRC",
+ .generate_fn = sd_dif_type1_generate_crc,
+ .verify_fn = sd_dif_type1_verify_crc,
+ .get_tag_fn = sd_dif_type1_get_tag,
+ .set_tag_fn = sd_dif_type1_set_tag,
+ .tuple_size = sizeof(struct sd_dif_tuple),
+ .tag_size = 0,
+};
+
+static struct blk_integrity dif_type1_integrity_ip = {
+ .name = "T10-DIF-TYPE1-IP",
+ .generate_fn = sd_dif_type1_generate_ip,
+ .verify_fn = sd_dif_type1_verify_ip,
+ .get_tag_fn = sd_dif_type1_get_tag,
+ .set_tag_fn = sd_dif_type1_set_tag,
+ .tuple_size = sizeof(struct sd_dif_tuple),
+ .tag_size = 0,
+};
+
+
+/*
+ * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
+ * tag space.
+ */
+static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
+{
+ void *buf = bix->data_buf;
+ struct sd_dif_tuple *sdt = bix->prot_buf;
+ unsigned int i;
+
+ for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
+ sdt->guard_tag = fn(buf, bix->sector_size);
+ sdt->ref_tag = 0;
+ sdt->app_tag = 0;
+
+ buf += bix->sector_size;
+ }
+}
+
+static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
+{
+ sd_dif_type3_generate(bix, sd_dif_crc_fn);
+}
+
+static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
+{
+ sd_dif_type3_generate(bix, sd_dif_ip_fn);
+}
+
+static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
+{
+ void *buf = bix->data_buf;
+ struct sd_dif_tuple *sdt = bix->prot_buf;
+ sector_t sector = bix->sector;
+ unsigned int i;
+ __u16 csum;
+
+ for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
+ /* Unwritten sectors */
+ if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
+ return 0;
+
+ csum = fn(buf, bix->sector_size);
+
+ if (sdt->guard_tag != csum) {
+ printk(KERN_ERR "%s: guard tag error on sector %lu " \
+ "(rcvd %04x, data %04x)\n", bix->disk_name,
+ (unsigned long)sector,
+ be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
+ return -EIO;
+ }
+
+ buf += bix->sector_size;
+ sector++;
+ }
+
+ return 0;
+}
+
+static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
+{
+ return sd_dif_type3_verify(bix, sd_dif_crc_fn);
+}
+
+static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
+{
+ return sd_dif_type3_verify(bix, sd_dif_ip_fn);
+}
+
+static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors)
+{
+ struct sd_dif_tuple *sdt = prot;
+ char *tag = tag_buf;
+ unsigned int i, j;
+
+ for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) {
+ sdt->app_tag = tag[j] << 8 | tag[j+1];
+ sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 |
+ tag[j+4] << 8 | tag[j+5];
+ }
+}
+
+static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors)
+{
+ struct sd_dif_tuple *sdt = prot;
+ char *tag = tag_buf;
+ unsigned int i, j;
+
+ for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
+ tag[j] = (sdt->app_tag & 0xff00) >> 8;
+ tag[j+1] = sdt->app_tag & 0xff;
+ tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24;
+ tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16;
+ tag[j+4] = (sdt->ref_tag & 0xff00) >> 8;
+ tag[j+5] = sdt->ref_tag & 0xff;
+ BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff);
+ }
+}
+
+static struct blk_integrity dif_type3_integrity_crc = {
+ .name = "T10-DIF-TYPE3-CRC",
+ .generate_fn = sd_dif_type3_generate_crc,
+ .verify_fn = sd_dif_type3_verify_crc,
+ .get_tag_fn = sd_dif_type3_get_tag,
+ .set_tag_fn = sd_dif_type3_set_tag,
+ .tuple_size = sizeof(struct sd_dif_tuple),
+ .tag_size = 0,
+};
+
+static struct blk_integrity dif_type3_integrity_ip = {
+ .name = "T10-DIF-TYPE3-IP",
+ .generate_fn = sd_dif_type3_generate_ip,
+ .verify_fn = sd_dif_type3_verify_ip,
+ .get_tag_fn = sd_dif_type3_get_tag,
+ .set_tag_fn = sd_dif_type3_set_tag,
+ .tuple_size = sizeof(struct sd_dif_tuple),
+ .tag_size = 0,
+};
+
+/*
+ * Configure exchange of protection information between OS and HBA.
+ */
+void sd_dif_config_host(struct scsi_disk *sdkp)
+{
+ struct scsi_device *sdp = sdkp->device;
+ struct gendisk *disk = sdkp->disk;
+ u8 type = sdkp->protection_type;
+
+ /* If this HBA doesn't support DIX, resort to normal I/O or DIF */
+ if (scsi_host_dix_capable(sdp->host, type) == 0) {
+
+ if (type == SD_DIF_TYPE0_PROTECTION)
+ return;
+
+ if (scsi_host_dif_capable(sdp->host, type) == 0) {
+ sd_printk(KERN_INFO, sdkp, "Type %d protection " \
+ "unsupported by HBA. Disabling DIF.\n", type);
+ sdkp->protection_type = 0;
+ return;
+ }
+
+ sd_printk(KERN_INFO, sdkp, "Enabling DIF Type %d protection\n",
+ type);
+
+ return;
+ }
+
+ /* Enable DMA of protection information */
+ if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
+ if (type == SD_DIF_TYPE3_PROTECTION)
+ blk_integrity_register(disk, &dif_type3_integrity_ip);
+ else
+ blk_integrity_register(disk, &dif_type1_integrity_ip);
+ else
+ if (type == SD_DIF_TYPE3_PROTECTION)
+ blk_integrity_register(disk, &dif_type3_integrity_crc);
+ else
+ blk_integrity_register(disk, &dif_type1_integrity_crc);
+
+ sd_printk(KERN_INFO, sdkp,
+ "Enabling %s integrity protection\n", disk->integrity->name);
+
+ /* Signal to block layer that we support sector tagging */
+ if (type && sdkp->ATO) {
+ if (type == SD_DIF_TYPE3_PROTECTION)
+ disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
+ else
+ disk->integrity->tag_size = sizeof(u16);
+
+ sd_printk(KERN_INFO, sdkp, "DIF application tag size %u\n",
+ disk->integrity->tag_size);
+ }
+}
+
+/*
+ * DIF DMA operation magic decoder ring.
+ */
+void sd_dif_op(struct scsi_cmnd *scmd, unsigned int dif, unsigned int dix)
+{
+ int csum_convert;
+
+ /* Convert checksum? */
+ if (scsi_host_get_guard(scmd->device->host) != SHOST_DIX_GUARD_CRC)
+ csum_convert = 1;
+ else
+ csum_convert = 0;
+
+ switch (scmd->cmnd[0]) {
+ case READ_10:
+ case READ_12:
+ case READ_16:
+ if (dif && dix)
+ if (csum_convert)
+ scmd->prot_op = SCSI_PROT_READ_CONVERT;
+ else
+ scmd->prot_op = SCSI_PROT_READ_PASS;
+ else if (dif && !dix)
+ scmd->prot_op = SCSI_PROT_READ_STRIP;
+ else if (!dif && dix)
+ scmd->prot_op = SCSI_PROT_READ_INSERT;
+
+ break;
+
+ case WRITE_10:
+ case WRITE_12:
+ case WRITE_16:
+ if (dif && dix)
+ if (csum_convert)
+ scmd->prot_op = SCSI_PROT_WRITE_CONVERT;
+ else
+ scmd->prot_op = SCSI_PROT_WRITE_PASS;
+ else if (dif && !dix)
+ scmd->prot_op = SCSI_PROT_WRITE_INSERT;
+ else if (!dif && dix)
+ scmd->prot_op = SCSI_PROT_WRITE_STRIP;
+
+ break;
+ }
+}
+
+/*
+ * The virtual start sector is the one that was originally submitted
+ * by the block layer. Due to partitioning, MD/DM cloning, etc. the
+ * actual physical start sector is likely to be different. Remap
+ * protection information to match the physical LBA.
+ *
+ * From a protocol perspective there's a slight difference between
+ * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
+ * reference tag is seeded in the CDB. This gives us the potential to
+ * avoid virt->phys remapping during write. However, at read time we
+ * don't know whether the virt sector is the same as when we wrote it
+ * (we could be reading from real disk as opposed to MD/DM device. So
+ * we always remap Type 2 making it identical to Type 1.
+ *
+ * Type 3 does not have a reference tag so no remapping is required.
+ */
+int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_sz)
+{
+ const int tuple_sz = sizeof(struct sd_dif_tuple);
+ struct bio *bio;
+ struct scsi_disk *sdkp;
+ struct sd_dif_tuple *sdt;
+ unsigned int i, j;
+ u32 phys, virt;
+
+ /* Already remapped? */
+ if (rq->cmd_flags & REQ_INTEGRITY)
+ return 0;
+
+ sdkp = rq->bio->bi_bdev->bd_disk->private_data;
+
+ if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
+ return 0;
+
+ rq->cmd_flags |= REQ_INTEGRITY;
+ phys = hw_sector & 0xffffffff;
+
+ __rq_for_each_bio(bio, rq) {
+ struct bio_vec *iv;
+
+ virt = bio->bi_integrity->bip_sector & 0xffffffff;
+
+ bip_for_each_vec(iv, bio->bi_integrity, i) {
+ sdt = kmap_atomic(iv->bv_page, KM_USER0)
+ + iv->bv_offset;
+
+ for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
+
+ if (be32_to_cpu(sdt->ref_tag) != virt)
+ goto error;
+
+ sdt->ref_tag = cpu_to_be32(phys);
+ virt++;
+ phys++;
+ }
+
+ kunmap_atomic(sdt, KM_USER0);
+ }
+ }
+
+ return 0;
+
+error:
+ kunmap_atomic(sdt, KM_USER0);
+ sd_printk(KERN_ERR, sdkp, "%s: virt %u, phys %u, ref %u\n",
+ __func__, virt, phys, be32_to_cpu(sdt->ref_tag));
+
+ return -EIO;
+}
+
+/*
+ * Remap physical sector values in the reference tag to the virtual
+ * values expected by the block layer.
+ */
+void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
+{
+ const int tuple_sz = sizeof(struct sd_dif_tuple);
+ struct scsi_disk *sdkp;
+ struct bio *bio;
+ struct sd_dif_tuple *sdt;
+ unsigned int i, j, sectors, sector_sz;
+ u32 phys, virt;
+
+ sdkp = scsi_disk(scmd->request->rq_disk);
+
+ if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
+ return;
+
+ sector_sz = scmd->device->sector_size;
+ sectors = good_bytes / sector_sz;
+
+ phys = scmd->request->sector & 0xffffffff;
+ if (sector_sz == 4096)
+ phys >>= 3;
+
+ __rq_for_each_bio(bio, scmd->request) {
+ struct bio_vec *iv;
+
+ virt = bio->bi_integrity->bip_sector & 0xffffffff;
+
+ bip_for_each_vec(iv, bio->bi_integrity, i) {
+ sdt = kmap_atomic(iv->bv_page, KM_USER0)
+ + iv->bv_offset;
+
+ for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
+
+ if (sectors == 0) {
+ kunmap_atomic(sdt, KM_USER0);
+ return;
+ }
+
+ if (be32_to_cpu(sdt->ref_tag) != phys &&
+ sdt->app_tag != 0xffff)
+ sdt->ref_tag = 0xffffffff; /* Bad ref */
+ else
+ sdt->ref_tag = cpu_to_be32(virt);
+
+ virt++;
+ phys++;
+ sectors--;
+ }
+
+ kunmap_atomic(sdt, KM_USER0);
+ }
+ }
+}
+
--
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