block: Add T10 Protection Information functions

The T10 Protection Information format is also used by some devices that
do not go through the SCSI layer (virtual block devices, NVMe). Relocate
the relevant functions to a block layer library that can be used without
involving SCSI.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

2 files changed, 20 insertions, 222 deletions

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 18a3358..9ece13f 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -62,7 +62,6 @@ comment "SCSI support type (disk, tape, CD-ROM)"
 config BLK_DEV_SD
 	tristate "SCSI disk support"
 	depends on SCSI
-	select CRC_T10DIF if BLK_DEV_INTEGRITY
 	---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/sd_dif.c b/drivers/scsi/sd_dif.c
index 2198abe..b7eaead 100644
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -21,7 +21,7 @@
  */
 
 #include <linux/blkdev.h>
-#include <linux/crc-t10dif.h>
+#include <linux/t10-pi.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -33,207 +33,8 @@
 #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_iter *iter, csum_fn *fn)
-{
-	void *buf = iter->data_buf;
-	struct sd_dif_tuple *sdt = iter->prot_buf;
-	sector_t seed = iter->seed;
-	unsigned int i;
-
-	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
-		sdt->guard_tag = fn(buf, iter->interval);
-		sdt->ref_tag = cpu_to_be32(seed & 0xffffffff);
-		sdt->app_tag = 0;
-
-		buf += iter->interval;
-		seed++;
-	}
-}
-
-static int sd_dif_type1_generate_crc(struct blk_integrity_iter *iter)
-{
-	sd_dif_type1_generate(iter, sd_dif_crc_fn);
-	return 0;
-}
-
-static int sd_dif_type1_generate_ip(struct blk_integrity_iter *iter)
-{
-	sd_dif_type1_generate(iter, sd_dif_ip_fn);
-	return 0;
-}
-
-static int sd_dif_type1_verify(struct blk_integrity_iter *iter, csum_fn *fn)
-{
-	void *buf = iter->data_buf;
-	struct sd_dif_tuple *sdt = iter->prot_buf;
-	sector_t seed = iter->seed;
-	unsigned int i;
-	__u16 csum;
-
-	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
-		/* Unwritten sectors */
-		if (sdt->app_tag == 0xffff)
-			return 0;
-
-		if (be32_to_cpu(sdt->ref_tag) != (seed & 0xffffffff)) {
-			printk(KERN_ERR
-			       "%s: ref tag error on sector %lu (rcvd %u)\n",
-			       iter->disk_name, (unsigned long)seed,
-			       be32_to_cpu(sdt->ref_tag));
-			return -EIO;
-		}
-
-		csum = fn(buf, iter->interval);
-
-		if (sdt->guard_tag != csum) {
-			printk(KERN_ERR "%s: guard tag error on sector %lu " \
-			       "(rcvd %04x, data %04x)\n", iter->disk_name,
-			       (unsigned long)seed,
-			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
-			return -EIO;
-		}
-
-		buf += iter->interval;
-		seed++;
-	}
-
-	return 0;
-}
-
-static int sd_dif_type1_verify_crc(struct blk_integrity_iter *iter)
-{
-	return sd_dif_type1_verify(iter, sd_dif_crc_fn);
-}
-
-static int sd_dif_type1_verify_ip(struct blk_integrity_iter *iter)
-{
-	return sd_dif_type1_verify(iter, sd_dif_ip_fn);
-}
-
-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,
-	.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,
-	.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_iter *iter, csum_fn *fn)
-{
-	void *buf = iter->data_buf;
-	struct sd_dif_tuple *sdt = iter->prot_buf;
-	unsigned int i;
-
-	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
-		sdt->guard_tag = fn(buf, iter->interval);
-		sdt->ref_tag = 0;
-		sdt->app_tag = 0;
-
-		buf += iter->interval;
-	}
-}
-
-static int sd_dif_type3_generate_crc(struct blk_integrity_iter *iter)
-{
-	sd_dif_type3_generate(iter, sd_dif_crc_fn);
-	return 0;
-}
-
-static int sd_dif_type3_generate_ip(struct blk_integrity_iter *iter)
-{
-	sd_dif_type3_generate(iter, sd_dif_ip_fn);
-	return 0;
-}
-
-static int sd_dif_type3_verify(struct blk_integrity_iter *iter, csum_fn *fn)
-{
-	void *buf = iter->data_buf;
-	struct sd_dif_tuple *sdt = iter->prot_buf;
-	sector_t seed = iter->seed;
-	unsigned int i;
-	__u16 csum;
-
-	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {
-		/* Unwritten sectors */
-		if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
-			return 0;
-
-		csum = fn(buf, iter->interval);
-
-		if (sdt->guard_tag != csum) {
-			printk(KERN_ERR "%s: guard tag error on sector %lu " \
-			       "(rcvd %04x, data %04x)\n", iter->disk_name,
-			       (unsigned long)seed,
-			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
-			return -EIO;
-		}
-
-		buf += iter->interval;
-		seed++;
-	}
-
-	return 0;
-}
-
-static int sd_dif_type3_verify_crc(struct blk_integrity_iter *iter)
-{
-	return sd_dif_type3_verify(iter, sd_dif_crc_fn);
-}
-
-static int sd_dif_type3_verify_ip(struct blk_integrity_iter *iter)
-{
-	return sd_dif_type3_verify(iter, sd_dif_ip_fn);
-}
-
-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,
-	.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,
-	.tuple_size		= sizeof(struct sd_dif_tuple),
-	.tag_size		= 0,
-};
-
 /*
  * Configure exchange of protection information between OS and HBA.
  */
@@ -257,16 +58,16 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 	/* 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);
+			blk_integrity_register(disk, &t10_pi_type3_ip);
 		else
-			blk_integrity_register(disk, &dif_type1_integrity_ip);
+			blk_integrity_register(disk, &t10_pi_type1_ip);
 
 		disk->integrity->flags |= BLK_INTEGRITY_IP_CHECKSUM;
 	} else
 		if (type == SD_DIF_TYPE3_PROTECTION)
-			blk_integrity_register(disk, &dif_type3_integrity_crc);
+			blk_integrity_register(disk, &t10_pi_type3_crc);
 		else
-			blk_integrity_register(disk, &dif_type1_integrity_crc);
+			blk_integrity_register(disk, &t10_pi_type1_crc);
 
 	sd_printk(KERN_NOTICE, sdkp,
 		  "Enabling DIX %s protection\n", disk->integrity->name);
@@ -308,10 +109,10 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 void sd_dif_prepare(struct request *rq, sector_t hw_sector,
 		    unsigned int sector_sz)
 {
-	const int tuple_sz = sizeof(struct sd_dif_tuple);
+	const int tuple_sz = sizeof(struct t10_pi_tuple);
 	struct bio *bio;
 	struct scsi_disk *sdkp;
-	struct sd_dif_tuple *sdt;
+	struct t10_pi_tuple *pi;
 	u32 phys, virt;
 
 	sdkp = rq->bio->bi_bdev->bd_disk->private_data;
@@ -334,19 +135,18 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector,
 		virt = bip_get_seed(bip) & 0xffffffff;
 
 		bip_for_each_vec(iv, bip, iter) {
-			sdt = kmap_atomic(iv.bv_page)
-				+ iv.bv_offset;
+			pi = kmap_atomic(iv.bv_page) + iv.bv_offset;
 
-			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {
+			for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {
 
-				if (be32_to_cpu(sdt->ref_tag) == virt)
-					sdt->ref_tag = cpu_to_be32(phys);
+				if (be32_to_cpu(pi->ref_tag) == virt)
+					pi->ref_tag = cpu_to_be32(phys);
 
 				virt++;
 				phys++;
 			}
 
-			kunmap_atomic(sdt);
+			kunmap_atomic(pi);
 		}
 
 		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
@@ -359,10 +159,10 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector,
  */
 void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
 {
-	const int tuple_sz = sizeof(struct sd_dif_tuple);
+	const int tuple_sz = sizeof(struct t10_pi_tuple);
 	struct scsi_disk *sdkp;
 	struct bio *bio;
-	struct sd_dif_tuple *sdt;
+	struct t10_pi_tuple *pi;
 	unsigned int j, sectors, sector_sz;
 	u32 phys, virt;
 
@@ -386,25 +186,24 @@ void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
 		virt = bip_get_seed(bip) & 0xffffffff;
 
 		bip_for_each_vec(iv, bip, iter) {
-			sdt = kmap_atomic(iv.bv_page)
-				+ iv.bv_offset;
+			pi = kmap_atomic(iv.bv_page) + iv.bv_offset;
 
-			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {
+			for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {
 
 				if (sectors == 0) {
-					kunmap_atomic(sdt);
+					kunmap_atomic(pi);
 					return;
 				}
 
-				if (be32_to_cpu(sdt->ref_tag) == phys)
-					sdt->ref_tag = cpu_to_be32(virt);
+				if (be32_to_cpu(pi->ref_tag) == phys)
+					pi->ref_tag = cpu_to_be32(virt);
 
 				virt++;
 				phys++;
 				sectors--;
 			}
 
-			kunmap_atomic(sdt);
+			kunmap_atomic(pi);
 		}
 	}
 }