/*
* sd_dif.c - SCSI Data Integrity Field
*
* Copyright (C) 2007, 2008 Oracle Corporation
* Written by: Martin K. Petersen <martin.petersen@oracle.com>
*
* 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, prot_op;
prot_op = 0;
/* 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)
prot_op = SCSI_PROT_READ_CONVERT;
else
prot_op = SCSI_PROT_READ_PASS;
else if (dif && !dix)
prot_op = SCSI_PROT_READ_STRIP;
else if (!dif && dix)
prot_op = SCSI_PROT_READ_INSERT;
break;
case WRITE_10:
case WRITE_12:
case WRITE_16:
if (dif && dix)
if (csum_convert)
prot_op = SCSI_PROT_WRITE_CONVERT;
else
prot_op = SCSI_PROT_WRITE_PASS;
else if (dif && !dix)
prot_op = SCSI_PROT_WRITE_INSERT;
else if (!dif && dix)
prot_op = SCSI_PROT_WRITE_STRIP;
break;
}
scsi_set_prot_op(scmd, prot_op);
scsi_set_prot_type(scmd, dif);
}
/*
* 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);
}
}
}
