diff options
Diffstat (limited to 'drivers/scsi/sd_dif.c')
| -rw-r--r-- | drivers/scsi/sd_dif.c | 538 |
1 files changed, 538 insertions, 0 deletions
diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c new file mode 100644 index 000000000000..4d17f3d35aac --- /dev/null +++ b/drivers/scsi/sd_dif.c @@ -0,0 +1,538 @@ +/* + * 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); + } + } +} + |