/* * 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; u8 *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; u8 *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; u8 *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; u8 *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; int dif, dix; dif = scsi_host_dif_capable(sdp->host, type); dix = scsi_host_dix_capable(sdp->host, type); if (!dix && scsi_host_dix_capable(sdp->host, 0)) { dif = 0; dix = 1; } if (!dix) 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_NOTICE, sdkp, "Enabling DIX %s protection\n", disk->integrity->name); /* Signal to block layer that we support sector tagging */ if (dif && 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_NOTICE, sdkp, "DIF application tag size %u\n", disk->integrity->tag_size); } } /* * 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, app %4x\n", __func__, virt, phys, be32_to_cpu(sdt->ref_tag), be16_to_cpu(sdt->app_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 = blk_rq_pos(scmd->request) & 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); } } }