469 строки
12 KiB
C
469 строки
12 KiB
C
/*
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* sd_dif.c - SCSI Data Integrity Field
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*
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* Copyright (C) 2007, 2008 Oracle Corporation
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* Written by: Martin K. Petersen <martin.petersen@oracle.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
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* USA.
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*
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*/
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#include <linux/blkdev.h>
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#include <linux/crc-t10dif.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_dbg.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_driver.h>
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#include <scsi/scsi_eh.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_ioctl.h>
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#include <scsi/scsicam.h>
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#include <net/checksum.h>
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#include "sd.h"
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typedef __u16 (csum_fn) (void *, unsigned int);
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static __u16 sd_dif_crc_fn(void *data, unsigned int len)
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{
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return cpu_to_be16(crc_t10dif(data, len));
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}
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static __u16 sd_dif_ip_fn(void *data, unsigned int len)
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{
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return ip_compute_csum(data, len);
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}
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/*
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* Type 1 and Type 2 protection use the same format: 16 bit guard tag,
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* 16 bit app tag, 32 bit reference tag.
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*/
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static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
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{
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void *buf = bix->data_buf;
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struct sd_dif_tuple *sdt = bix->prot_buf;
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sector_t sector = bix->sector;
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unsigned int i;
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for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
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sdt->guard_tag = fn(buf, bix->sector_size);
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sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
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sdt->app_tag = 0;
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buf += bix->sector_size;
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sector++;
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}
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}
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static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix)
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{
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sd_dif_type1_generate(bix, sd_dif_crc_fn);
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}
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static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix)
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{
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sd_dif_type1_generate(bix, sd_dif_ip_fn);
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}
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static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
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{
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void *buf = bix->data_buf;
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struct sd_dif_tuple *sdt = bix->prot_buf;
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sector_t sector = bix->sector;
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unsigned int i;
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__u16 csum;
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for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
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/* Unwritten sectors */
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if (sdt->app_tag == 0xffff)
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return 0;
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/* Bad ref tag received from disk */
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if (sdt->ref_tag == 0xffffffff) {
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printk(KERN_ERR
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"%s: bad phys ref tag on sector %lu\n",
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bix->disk_name, (unsigned long)sector);
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return -EIO;
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}
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if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
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printk(KERN_ERR
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"%s: ref tag error on sector %lu (rcvd %u)\n",
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bix->disk_name, (unsigned long)sector,
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be32_to_cpu(sdt->ref_tag));
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return -EIO;
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}
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csum = fn(buf, bix->sector_size);
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if (sdt->guard_tag != csum) {
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printk(KERN_ERR "%s: guard tag error on sector %lu " \
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"(rcvd %04x, data %04x)\n", bix->disk_name,
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(unsigned long)sector,
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be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
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return -EIO;
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}
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buf += bix->sector_size;
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sector++;
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}
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return 0;
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}
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static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
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{
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return sd_dif_type1_verify(bix, sd_dif_crc_fn);
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}
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static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
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{
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return sd_dif_type1_verify(bix, sd_dif_ip_fn);
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}
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/*
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* Functions for interleaving and deinterleaving application tags
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*/
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static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors)
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{
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struct sd_dif_tuple *sdt = prot;
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u8 *tag = tag_buf;
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unsigned int i, j;
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for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
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sdt->app_tag = tag[j] << 8 | tag[j+1];
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BUG_ON(sdt->app_tag == 0xffff);
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}
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}
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static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors)
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{
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struct sd_dif_tuple *sdt = prot;
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u8 *tag = tag_buf;
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unsigned int i, j;
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for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
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tag[j] = (sdt->app_tag & 0xff00) >> 8;
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tag[j+1] = sdt->app_tag & 0xff;
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}
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}
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static struct blk_integrity dif_type1_integrity_crc = {
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.name = "T10-DIF-TYPE1-CRC",
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.generate_fn = sd_dif_type1_generate_crc,
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.verify_fn = sd_dif_type1_verify_crc,
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.get_tag_fn = sd_dif_type1_get_tag,
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.set_tag_fn = sd_dif_type1_set_tag,
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.tuple_size = sizeof(struct sd_dif_tuple),
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.tag_size = 0,
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};
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static struct blk_integrity dif_type1_integrity_ip = {
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.name = "T10-DIF-TYPE1-IP",
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.generate_fn = sd_dif_type1_generate_ip,
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.verify_fn = sd_dif_type1_verify_ip,
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.get_tag_fn = sd_dif_type1_get_tag,
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.set_tag_fn = sd_dif_type1_set_tag,
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.tuple_size = sizeof(struct sd_dif_tuple),
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.tag_size = 0,
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};
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/*
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* Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
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* tag space.
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*/
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static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
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{
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void *buf = bix->data_buf;
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struct sd_dif_tuple *sdt = bix->prot_buf;
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unsigned int i;
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for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
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sdt->guard_tag = fn(buf, bix->sector_size);
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sdt->ref_tag = 0;
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sdt->app_tag = 0;
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buf += bix->sector_size;
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}
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}
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static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
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{
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sd_dif_type3_generate(bix, sd_dif_crc_fn);
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}
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static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
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{
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sd_dif_type3_generate(bix, sd_dif_ip_fn);
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}
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static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
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{
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void *buf = bix->data_buf;
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struct sd_dif_tuple *sdt = bix->prot_buf;
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sector_t sector = bix->sector;
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unsigned int i;
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__u16 csum;
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for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
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/* Unwritten sectors */
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if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
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return 0;
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csum = fn(buf, bix->sector_size);
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if (sdt->guard_tag != csum) {
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printk(KERN_ERR "%s: guard tag error on sector %lu " \
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"(rcvd %04x, data %04x)\n", bix->disk_name,
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(unsigned long)sector,
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be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
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return -EIO;
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}
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buf += bix->sector_size;
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sector++;
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}
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return 0;
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}
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static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
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{
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return sd_dif_type3_verify(bix, sd_dif_crc_fn);
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}
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static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
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{
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return sd_dif_type3_verify(bix, sd_dif_ip_fn);
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}
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static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors)
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{
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struct sd_dif_tuple *sdt = prot;
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u8 *tag = tag_buf;
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unsigned int i, j;
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for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) {
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sdt->app_tag = tag[j] << 8 | tag[j+1];
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sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 |
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tag[j+4] << 8 | tag[j+5];
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}
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}
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static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors)
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{
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struct sd_dif_tuple *sdt = prot;
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u8 *tag = tag_buf;
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unsigned int i, j;
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for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
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tag[j] = (sdt->app_tag & 0xff00) >> 8;
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tag[j+1] = sdt->app_tag & 0xff;
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tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24;
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tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16;
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tag[j+4] = (sdt->ref_tag & 0xff00) >> 8;
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tag[j+5] = sdt->ref_tag & 0xff;
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BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff);
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}
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}
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static struct blk_integrity dif_type3_integrity_crc = {
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.name = "T10-DIF-TYPE3-CRC",
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.generate_fn = sd_dif_type3_generate_crc,
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.verify_fn = sd_dif_type3_verify_crc,
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.get_tag_fn = sd_dif_type3_get_tag,
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.set_tag_fn = sd_dif_type3_set_tag,
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.tuple_size = sizeof(struct sd_dif_tuple),
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.tag_size = 0,
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};
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static struct blk_integrity dif_type3_integrity_ip = {
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.name = "T10-DIF-TYPE3-IP",
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.generate_fn = sd_dif_type3_generate_ip,
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.verify_fn = sd_dif_type3_verify_ip,
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.get_tag_fn = sd_dif_type3_get_tag,
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.set_tag_fn = sd_dif_type3_set_tag,
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.tuple_size = sizeof(struct sd_dif_tuple),
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.tag_size = 0,
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};
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/*
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* Configure exchange of protection information between OS and HBA.
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*/
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void sd_dif_config_host(struct scsi_disk *sdkp)
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{
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struct scsi_device *sdp = sdkp->device;
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struct gendisk *disk = sdkp->disk;
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u8 type = sdkp->protection_type;
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int dif, dix;
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dif = scsi_host_dif_capable(sdp->host, type);
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dix = scsi_host_dix_capable(sdp->host, type);
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if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
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dif = 0; dix = 1;
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}
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if (!dix)
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return;
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/* Enable DMA of protection information */
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if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
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if (type == SD_DIF_TYPE3_PROTECTION)
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blk_integrity_register(disk, &dif_type3_integrity_ip);
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else
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blk_integrity_register(disk, &dif_type1_integrity_ip);
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else
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if (type == SD_DIF_TYPE3_PROTECTION)
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blk_integrity_register(disk, &dif_type3_integrity_crc);
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else
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blk_integrity_register(disk, &dif_type1_integrity_crc);
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sd_printk(KERN_NOTICE, sdkp,
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"Enabling DIX %s protection\n", disk->integrity->name);
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/* Signal to block layer that we support sector tagging */
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if (dif && type && sdkp->ATO) {
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if (type == SD_DIF_TYPE3_PROTECTION)
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disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
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else
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disk->integrity->tag_size = sizeof(u16);
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sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
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disk->integrity->tag_size);
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}
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}
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/*
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* The virtual start sector is the one that was originally submitted
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* by the block layer. Due to partitioning, MD/DM cloning, etc. the
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* actual physical start sector is likely to be different. Remap
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* protection information to match the physical LBA.
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*
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* From a protocol perspective there's a slight difference between
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* Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
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* reference tag is seeded in the CDB. This gives us the potential to
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* avoid virt->phys remapping during write. However, at read time we
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* don't know whether the virt sector is the same as when we wrote it
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* (we could be reading from real disk as opposed to MD/DM device. So
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* we always remap Type 2 making it identical to Type 1.
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*
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* Type 3 does not have a reference tag so no remapping is required.
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*/
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void sd_dif_prepare(struct request *rq, sector_t hw_sector,
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unsigned int sector_sz)
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{
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const int tuple_sz = sizeof(struct sd_dif_tuple);
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struct bio *bio;
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struct scsi_disk *sdkp;
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struct sd_dif_tuple *sdt;
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unsigned int i, j;
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u32 phys, virt;
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sdkp = rq->bio->bi_bdev->bd_disk->private_data;
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if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
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return;
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phys = hw_sector & 0xffffffff;
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__rq_for_each_bio(bio, rq) {
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struct bio_vec *iv;
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/* Already remapped? */
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if (bio_flagged(bio, BIO_MAPPED_INTEGRITY))
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break;
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virt = bio->bi_integrity->bip_sector & 0xffffffff;
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bip_for_each_vec(iv, bio->bi_integrity, i) {
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sdt = kmap_atomic(iv->bv_page)
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+ iv->bv_offset;
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for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
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if (be32_to_cpu(sdt->ref_tag) == virt)
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sdt->ref_tag = cpu_to_be32(phys);
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virt++;
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phys++;
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}
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kunmap_atomic(sdt);
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}
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bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY);
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}
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}
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/*
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* Remap physical sector values in the reference tag to the virtual
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* values expected by the block layer.
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*/
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void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
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{
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const int tuple_sz = sizeof(struct sd_dif_tuple);
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struct scsi_disk *sdkp;
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struct bio *bio;
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struct sd_dif_tuple *sdt;
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unsigned int i, j, sectors, sector_sz;
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u32 phys, virt;
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sdkp = scsi_disk(scmd->request->rq_disk);
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if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
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return;
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sector_sz = scmd->device->sector_size;
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sectors = good_bytes / sector_sz;
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phys = blk_rq_pos(scmd->request) & 0xffffffff;
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if (sector_sz == 4096)
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phys >>= 3;
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__rq_for_each_bio(bio, scmd->request) {
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struct bio_vec *iv;
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virt = bio->bi_integrity->bip_sector & 0xffffffff;
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bip_for_each_vec(iv, bio->bi_integrity, i) {
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sdt = kmap_atomic(iv->bv_page)
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+ iv->bv_offset;
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for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
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if (sectors == 0) {
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kunmap_atomic(sdt);
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return;
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}
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if (be32_to_cpu(sdt->ref_tag) == phys)
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sdt->ref_tag = cpu_to_be32(virt);
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virt++;
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phys++;
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sectors--;
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}
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kunmap_atomic(sdt);
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}
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}
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}
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