SCSI Data Integrity Support

@@ -778,6 +778,11 @@ void scsi_release_buffers(struct scsi_cm
 		kmem_cache_free(scsi_sdb_cache, bidi_sdb);
 		cmd->request->next_rq->special = NULL;
 	}
+
+	if (scsi_prot_sg_count(cmd)) {
+		scsi_free_sgtable(cmd->prot_sdb);
+		kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
+	}
 }
 EXPORT_SYMBOL(scsi_release_buffers);
 

@@ -1031,6 +1036,32 @@ static int scsi_init_sgtable(struct requ
 	return BLKPREP_OK;
 }
 
+static int scsi_protect_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+{
+	struct request *req;
+	struct scsi_data_buffer *pdb;
+	int ivecs, count;
+
+	req = cmd->request;
+
+	pdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
+	if (unlikely(pdb == NULL))
+		return BLKPREP_DEFER;
+
+	ivecs = blk_rq_count_integrity_sg(req);
+
+	if (unlikely(scsi_alloc_sgtable(pdb, ivecs, gfp_mask)))
+		return BLKPREP_DEFER;
+
+	count = blk_rq_map_integrity_sg(req, pdb->table.sgl);
+	BUG_ON(unlikely(count > ivecs));
+
+	cmd->prot_sdb = pdb;
+	cmd->prot_sdb->table.nents = count;
+
+	return BLKPREP_OK;
+}
+
 /*
  * Function:    scsi_init_io()
  *

@@ -1060,6 +1091,13 @@ int scsi_init_io(struct scsi_cmnd *cmd, 
 		error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb,
 								    GFP_ATOMIC);
 		if (error)
+			goto err_exit;
+	}
+
+	if (blk_integrity_rq(cmd->request)) {
+		error = scsi_protect_io(cmd, gfp_mask);
+
+		if (error != BLKPREP_OK)
 			goto err_exit;
 	}
 

@@ -882,6 +882,9 @@ static int scsi_add_lun(struct scsi_devi
 
 	if (*bflags & BLIST_USE_10_BYTE_MS)
 		sdev->use_10_for_ms = 1;
+
+	if (inq_result[5] & 0x1)
+		sdev->protection = 1;
 
 	/* set the device running here so that slave configure
 	 * may do I/O */

@@ -88,6 +88,8 @@ struct scsi_cmnd {
 
 	/* These elements define the operation we ultimately want to perform */
 	struct scsi_data_buffer sdb;
+	struct scsi_data_buffer *prot_sdb;
+
 	unsigned underflow;	/* Return error if less than
 				   this amount is transferred */
 

@@ -209,4 +211,22 @@ static inline int scsi_sg_copy_to_buffer
 				 buf, buflen);
 }
 
+static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
+{
+	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
+}
+
+static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
+{
+	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
+}
+
+static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
+{
+	return cmd->prot_sdb;
+}
+
+#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
+	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
+
 #endif /* _SCSI_SCSI_CMND_H */

@@ -140,6 +140,7 @@ struct scsi_device {
 	unsigned guess_capacity:1;	/* READ_CAPACITY might be too high by 1 */
 	unsigned retry_hwerror:1;	/* Retry HARDWARE_ERROR */
 	unsigned last_sector_bug:1;	/* Always read last sector in a 1 sector read */
+	unsigned protection:1;		/* Data Integrity Field */
 
 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
 	struct list_head event_list;	/* asserted events */

@@ -293,11 +293,6 @@ static int sd_major(int major_idx)
 		BUG();
 		return 0;	/* shut up gcc */
 	}
-}
-
-static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
-{
-	return container_of(disk->private_data, struct scsi_disk, driver);
 }
 
 static struct scsi_disk *__scsi_disk_get(struct gendisk *disk)

@@ -48,6 +48,11 @@ struct scsi_disk {
 };
 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)
 
+static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
+{
+	return container_of(disk->private_data, struct scsi_disk, driver);
+}
+
 #define sd_printk(prefix, sdsk, fmt, a...)				\
         (sdsk)->disk ?							\
 	sdev_printk(prefix, (sdsk)->device, "[%s] " fmt,		\

new file mode 100644
@@ -0,0 +1,8 @@
+#ifndef _LINUX_CRC_T10DIF_H
+#define _LINUX_CRC_T10DIF_H
+
+#include <linux/types.h>
+
+__u16 crc_t10dif(unsigned char const *, size_t);
+
+#endif

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@@ -58,8 +58,8 @@
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_ioctl.h>
 #include <scsi/scsicam.h>
-#include <scsi/sd.h>
 
+#include "sd.h"
 #include "scsi_logging.h"
 
 MODULE_AUTHOR("Eric Youngdale");

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@@ -249,6 +249,8 @@ shost_rd_attr(can_queue, "%hd\n");
 shost_rd_attr(can_queue, "%hd\n");
 shost_rd_attr(sg_tablesize, "%hu\n");
 shost_rd_attr(unchecked_isa_dma, "%d\n");
+shost_rd_attr(prot_capabilities, "%u\n");
+shost_rd_attr(prot_guard_type, "%hd\n");
 shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");
 
 static struct attribute *scsi_sysfs_shost_attrs[] = {

@@ -263,6 +265,8 @@ static struct attribute *scsi_sysfs_shos
 	&dev_attr_hstate.attr,
 	&dev_attr_supported_mode.attr,
 	&dev_attr_active_mode.attr,
+	&dev_attr_prot_capabilities.attr,
+	&dev_attr_prot_guard_type.attr,
 	NULL
 };
 

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@@ -333,6 +333,9 @@ static int scsi_check_sense(struct scsi_
 		return /* soft_error */ SUCCESS;
 
 	case ABORTED_COMMAND:
+		if (sshdr.asc == 0x10) /* DIF */
+			return SUCCESS;
+
 		return NEEDS_RETRY;
 	case NOT_READY:
 	case UNIT_ATTENTION:

@@ -945,6 +945,10 @@ void scsi_io_completion(struct scsi_cmnd
 				scsi_requeue_command(q, cmd);
 				return;
 			} else {
+				if (sshdr.asc == 0x10) { /* DIF */
+					scsi_print_result(cmd);
+					scsi_print_sense("", cmd);
+				}
 				scsi_end_request(cmd, -EIO, this_count, 1);
 				return;
 			}

@@ -653,7 +653,9 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd 
 	ses->sdb = scmd->sdb;
 	ses->next_rq = scmd->request->next_rq;
 	ses->result = scmd->result;
+	ses->prot_op = scmd->prot_op;
 
+	scmd->prot_op = SCSI_PROT_NORMAL;
 	scmd->cmnd = ses->eh_cmnd;
 	memset(scmd->cmnd, 0, BLK_MAX_CDB);
 	memset(&scmd->sdb, 0, sizeof(scmd->sdb));

@@ -711,6 +713,7 @@ void scsi_eh_restore_cmnd(struct scsi_cm
 	scmd->sdb = ses->sdb;
 	scmd->request->next_rq = ses->next_rq;
 	scmd->result = ses->result;
+	scmd->prot_op = ses->prot_op;
 }
 EXPORT_SYMBOL(scsi_eh_restore_cmnd);
 

@@ -77,6 +77,8 @@ struct scsi_cmnd {
 	int retries;
 	int allowed;
 	int timeout_per_command;
+
+	unsigned char prot_op;
 
 	unsigned short cmd_len;
 	enum dma_data_direction sc_data_direction;

@@ -211,6 +213,32 @@ static inline int scsi_sg_copy_to_buffer
 				 buf, buflen);
 }
 
+/*
+ * The operations below are hints that tell the controller driver how
+ * to handle I/Os with DIF or similar types of protection information.
+ */
+
+enum scsi_prot_operations {
+	/* Normal I/O */
+	SCSI_PROT_NORMAL = 0,
+
+	/* OS-HBA: Protected, HBA-Target: Unprotected */
+	SCSI_PROT_READ_INSERT,
+	SCSI_PROT_WRITE_STRIP,
+
+	/* OS-HBA: Unprotected, HBA-Target: Protected */
+	SCSI_PROT_READ_STRIP,
+	SCSI_PROT_WRITE_INSERT,
+
+	/* OS-HBA: Protected, HBA-Target: Protected */
+	SCSI_PROT_READ_PASS,
+	SCSI_PROT_WRITE_PASS,
+
+	/* OS-HBA: Protected, HBA-Target: Protected, checksum conversion */
+	SCSI_PROT_READ_CONVERT,
+	SCSI_PROT_WRITE_CONVERT,
+};
+
 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
 {
 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;

@@ -75,6 +75,7 @@ struct scsi_eh_save {
 	int result;
 	enum dma_data_direction data_direction;
 	unsigned char cmd_len;
+	unsigned char prot_op;
 	unsigned char *cmnd;
 	struct scsi_data_buffer sdb;
 	struct request *next_rq;

@@ -234,6 +234,24 @@ sd_show_allow_restart(struct device *dev
 	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);
 }
 
+static ssize_t
+sd_show_protection_type(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+
+	return snprintf(buf, 20, "%u\n", sdkp->protection_type);
+}
+
+static ssize_t
+sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,
+		    char *buf)
+{
+	struct scsi_disk *sdkp = to_scsi_disk(dev);
+
+	return snprintf(buf, 20, "%u\n", sdkp->ATO);
+}
+
 static struct device_attribute sd_disk_attrs[] = {
 	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,
 	       sd_store_cache_type),

@@ -242,6 +260,8 @@ static struct device_attribute sd_disk_a
 	       sd_store_allow_restart),
 	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,
 	       sd_store_manage_start_stop),
+	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),
+	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),
 	__ATTR_NULL,
 };
 

@@ -1163,6 +1183,53 @@ sd_spinup_disk(struct scsi_disk *sdkp)
 	}
 }
 
+
+/*
+ * Determine whether disk supports Data Integrity Field.
+ */
+void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
+{
+	struct scsi_device *sdp = sdkp->device;
+	u8 type;
+
+	if (sdp->protection == 0 || (buffer[12] & 1) == 0)
+		type = 0;
+	else
+		type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
+
+	switch (type) {
+	case SD_DIF_TYPE0_PROTECTION:
+		sd_printk(KERN_NOTICE, sdkp, "formatted without data " \
+			  "integrity protection\n");
+		sdkp->protection_type = 0;
+		break;
+
+	case SD_DIF_TYPE1_PROTECTION:
+	case SD_DIF_TYPE3_PROTECTION:
+		sd_printk(KERN_NOTICE, sdkp, "formatted with DIF Type %d " \
+			  "protection\n", type);
+		sdkp->protection_type = type;
+		break;
+
+	case SD_DIF_TYPE2_PROTECTION:
+		sd_printk(KERN_ERR, sdkp, "formatted with DIF Type 2 "	\
+			  "protection which is currently unsupported. "	\
+			  "Disabling disk!\n");
+		goto disable;
+
+	default:
+		sd_printk(KERN_ERR, sdkp, "formatted with unknown "	\
+			  "protection type %d. Disabling disk!\n", type);
+		goto disable;
+	}
+
+	return;
+
+disable:
+	sdkp->protection_type = 0;
+	sdkp->capacity = 0;
+}
+
 /*
  * read disk capacity
  */

@@ -1172,7 +1239,8 @@ sd_read_capacity(struct scsi_disk *sdkp,
 	unsigned char cmd[16];
 	int the_result, retries;
 	int sector_size = 0;
-	int longrc = 0;
+	/* Force READ CAPACITY(16) when PROTECT=1 */
+	int longrc = sdkp->device->protection ? 1 : 0;
 	struct scsi_sense_hdr sshdr;
 	int sense_valid = 0;
 	struct scsi_device *sdp = sdkp->device;

@@ -1184,8 +1252,8 @@ repeat:
 			memset((void *) cmd, 0, 16);
 			cmd[0] = SERVICE_ACTION_IN;
 			cmd[1] = SAI_READ_CAPACITY_16;
-			cmd[13] = 12;
-			memset((void *) buffer, 0, 12);
+			cmd[13] = 13;
+			memset((void *) buffer, 0, 13);
 		} else {
 			cmd[0] = READ_CAPACITY;
 			memset((void *) &cmd[1], 0, 9);

@@ -1193,7 +1261,7 @@ repeat:
 		}
 		
 		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
-					      buffer, longrc ? 12 : 8, &sshdr,
+					      buffer, longrc ? 13 : 8, &sshdr,
 					      SD_TIMEOUT, SD_MAX_RETRIES);
 
 		if (media_not_present(sdkp, &sshdr))

@@ -1268,6 +1336,8 @@ repeat:
 			
 		sector_size = (buffer[8] << 24) |
 			(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
+
+		sd_read_protection_type(sdkp, buffer);
 	}	
 
 	/* Some devices return the total number of sectors, not the

@@ -1529,6 +1599,56 @@ defaults:
 	sdkp->DPOFUA = 0;
 }
 
+/*
+ * The ATO bit indicates whether the DIF application tag is available
+ * for use by the operating system.
+ */
+void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
+{
+	int res, offset;
+	struct scsi_device *sdp = sdkp->device;
+	struct scsi_mode_data data;
+	struct scsi_sense_hdr sshdr;
+
+	if (sdp->type != TYPE_DISK)
+		return;
+
+	if (sdkp->protection_type == 0)
+		return;
+
+	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,
+			      SD_MAX_RETRIES, &data, &sshdr);
+
+	if (!scsi_status_is_good(res) || !data.header_length ||
+	    data.length < 6) {
+		sd_printk(KERN_WARNING, sdkp,
+			  "getting Control mode page failed, assume no ATO\n");
+
+		if (scsi_sense_valid(&sshdr))
+			sd_print_sense_hdr(sdkp, &sshdr);
+
+		goto no_ato;
+	}
+
+	offset = data.header_length + data.block_descriptor_length;
+
+	if ((buffer[offset] & 0x3f) != 0x0a) {
+		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");
+		goto no_ato;
+	}
+
+	if ((buffer[offset + 5] & 0x80) == 0)
+		goto no_ato;
+
+	sdkp->ATO = 1;
+	sd_printk(KERN_NOTICE, sdkp, "ATO Enabled\n");
+
+	return;
+
+no_ato:
+	sd_printk(KERN_NOTICE, sdkp, "ATO Disabled\n");
+}
+
 /**
  *	sd_revalidate_disk - called the first time a new disk is seen,
  *	performs disk spin up, read_capacity, etc.

@@ -1565,6 +1685,7 @@ static int sd_revalidate_disk(struct gen
 	sdkp->write_prot = 0;
 	sdkp->WCE = 0;
 	sdkp->RCD = 0;
+	sdkp->ATO = 0;
 
 	sd_spinup_disk(sdkp);
 

@@ -1576,6 +1697,7 @@ static int sd_revalidate_disk(struct gen
 		sd_read_capacity(sdkp, buffer);
 		sd_read_write_protect_flag(sdkp, buffer);
 		sd_read_cache_type(sdkp, buffer);
+		sd_read_app_tag_own(sdkp, buffer);
 	}
 
 	/*

@@ -41,7 +41,9 @@ struct scsi_disk {
 	u32		index;
 	u8		media_present;
 	u8		write_prot;
+	u8		protection_type;/* Data Integrity Field */
 	unsigned	previous_state : 1;
+	unsigned	ATO : 1;	/* state of disk ATO bit */
 	unsigned	WCE : 1;	/* state of disk WCE bit */
 	unsigned	RCD : 1;	/* state of disk RCD bit, unused */
 	unsigned	DPOFUA : 1;	/* state of disk DPOFUA bit */

@@ -59,4 +61,25 @@ static inline struct scsi_disk *scsi_dis
 		    (sdsk)->disk->disk_name, ##a) :			\
 	sdev_printk(prefix, (sdsk)->device, fmt, ##a)
 
+/*
+ * A DIF-capable target device can be formatted with different
+ * protection schemes.  Currently 0 through 3 are defined:
+ *
+ * Type 0 is regular (unprotected) I/O
+ *
+ * Type 1 defines the contents of the guard and reference tags
+ *
+ * Type 2 defines the contents of the guard and reference tags and
+ * uses 32-byte commands to seed the latter
+ *
+ * Type 3 defines the contents of the guard tag only
+ */
+
+enum sd_dif_target_protection_types {
+	SD_DIF_TYPE0_PROTECTION = 0x0,
+	SD_DIF_TYPE1_PROTECTION = 0x1,
+	SD_DIF_TYPE2_PROTECTION = 0x2,
+	SD_DIF_TYPE3_PROTECTION = 0x3,
+};
+
 #endif /* _SCSI_DISK_H */

@@ -374,6 +374,7 @@ static int sd_prep_fn(struct request_que
 	struct scsi_cmnd *SCpnt;
 	struct scsi_device *sdp = q->queuedata;
 	struct gendisk *disk = rq->rq_disk;
+	struct scsi_disk *sdkp;
 	sector_t block = rq->sector;
 	unsigned int this_count = rq->nr_sectors;
 	unsigned int timeout = sdp->timeout;

@@ -390,6 +391,7 @@ static int sd_prep_fn(struct request_que
 	if (ret != BLKPREP_OK)
 		goto out;
 	SCpnt = rq->special;
+	sdkp = scsi_disk(disk);
 
 	/* from here on until we're complete, any goto out
 	 * is used for a killable error condition */

@@ -479,6 +481,11 @@ static int sd_prep_fn(struct request_que
 		}
 		SCpnt->cmnd[0] = WRITE_6;
 		SCpnt->sc_data_direction = DMA_TO_DEVICE;
+
+		if (blk_integrity_rq(rq) &&
+		    sd_dif_prepare(rq, block, sdp->sector_size) == -EIO)
+			goto out;
+
 	} else if (rq_data_dir(rq) == READ) {
 		SCpnt->cmnd[0] = READ_6;
 		SCpnt->sc_data_direction = DMA_FROM_DEVICE;

@@ -493,8 +500,15 @@ static int sd_prep_fn(struct request_que
 					"writing" : "reading", this_count,
 					rq->nr_sectors));
 
-	SCpnt->cmnd[1] = 0;
-	
+	if (sdkp->protection_type || scsi_prot_sg_count(SCpnt))
+		sd_dif_op(SCpnt);
+
+	/* Set RDPROTECT/WRPROTECT if disk is formatted with DIF */
+	if (scsi_host_dif_type(sdp->host, sdkp->protection_type))
+		SCpnt->cmnd[1] = 1 << 5;
+	else
+		SCpnt->cmnd[1] = 0;
+
 	if (block > 0xffffffff) {
 		SCpnt->cmnd[0] += READ_16 - READ_6;
 		SCpnt->cmnd[1] |= blk_fua_rq(rq) ? 0x8 : 0;

@@ -512,6 +526,7 @@ static int sd_prep_fn(struct request_que
 		SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
 		SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
 	} else if ((this_count > 0xff) || (block > 0x1fffff) ||
+		   SCpnt->device->protection ||
 		   SCpnt->device->use_10_for_rw) {
 		if (this_count > 0xffff)
 			this_count = 0xffff;

@@ -1025,7 +1040,8 @@ static int sd_done(struct scsi_cmnd *SCp
 		good_bytes = xfer_size;
 		break;
 	case ILLEGAL_REQUEST:
-		if (SCpnt->device->use_10_for_rw &&
+		if (SCpnt->device->protection == 0 &&
+		    SCpnt->device->use_10_for_rw &&
 		    (SCpnt->cmnd[0] == READ_10 ||
 		     SCpnt->cmnd[0] == WRITE_10))
 			SCpnt->device->use_10_for_rw = 0;

@@ -1038,6 +1054,9 @@ static int sd_done(struct scsi_cmnd *SCp
 		break;
 	}
  out:
+	if (rq_data_dir(SCpnt->request) == READ && scsi_prot_sg_count(SCpnt))
+		sd_dif_complete(SCpnt, good_bytes);
+
 	return good_bytes;
 }
 

@@ -1831,6 +1850,7 @@ static int sd_probe(struct device *dev)
 
 	dev_set_drvdata(dev, sdkp);
 	add_disk(gd);
+	sd_dif_config_host(sdkp);
 
 	sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
 		  sdp->removable ? "removable " : "");

@@ -82,4 +82,31 @@ enum sd_dif_target_protection_types {
 	SD_DIF_TYPE3_PROTECTION = 0x3,
 };
 
+/*
+ * Data Integrity Field tuple.
+ */
+struct sd_dif_tuple {
+       __be16 guard_tag;	/* Checksum */
+       __be16 app_tag;		/* Opaque storage */
+       __be32 ref_tag;		/* Target LBA or indirect LBA */
+};
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+extern unsigned char sd_dif_op(struct scsi_cmnd *);
+extern void sd_dif_config_disk(struct scsi_disk *, unsigned char *);
+extern void sd_dif_config_host(struct scsi_disk *);
+extern int sd_dif_prepare(struct request *rq, sector_t, unsigned int);
+extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+
+#define sd_dif_op(a)				(0)
+#define sd_dif_config_disk(a, b)		do { } while (0)
+#define sd_dif_config_host(a)			do { } while (0)
+#define sd_dif_prepare(a, b, c)			(0)
+#define sd_dif_complete(a, b)			(0)
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
 #endif /* _SCSI_DISK_H */

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