[SCSI] sd: Detach DIF from block integrity infrastructure

So far we have only issued DIF commands if CONFIG_BLK_DEV_INTEGRITY is
enabled.  However, communication between initiator and target should be
independent of protection information DMA.  There are DIF-only host
adapters coming out that will be able to take advantage of this.

Move the relevant DIF bits to sd.c.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 8dd96dc..1e0a0b0 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -370,6 +370,31 @@ static void scsi_disk_put(struct scsi_disk *sdkp)
        mutex_unlock(&sd_ref_mutex);
 }
 
+static void sd_prot_op(struct scsi_cmnd *scmd, unsigned int dif)
+{
+       unsigned int prot_op = SCSI_PROT_NORMAL;
+       unsigned int dix = scsi_prot_sg_count(scmd);
+
+       if (scmd->sc_data_direction == DMA_FROM_DEVICE) {
+               if (dif && dix)
+                       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;
+       } else {
+               if (dif && dix)
+                       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;
+       }
+
+       scsi_set_prot_op(scmd, prot_op);
+       scsi_set_prot_type(scmd, dif);
+}
+
 /**
  *     sd_init_command - build a scsi (read or write) command from
  *     information in the request structure.
@@ -578,8 +603,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 
        /* If DIF or DIX is enabled, tell HBA how to handle request */
        if (host_dif || scsi_prot_sg_count(SCpnt))
-               sd_dif_op(SCpnt, host_dif, scsi_prot_sg_count(SCpnt),
-                         sdkp->protection_type);
+               sd_prot_op(SCpnt, host_dif);
 
        /*
         * We shouldn't disconnect in the middle of a sector, so with a dumb
@@ -1238,34 +1262,33 @@ void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)
        u8 type;
 
        if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
-               type = 0;
-       else
-               type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
+               return;
+
+       type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
+
+       if (type == sdkp->protection_type || !sdkp->first_scan)
+               return;
 
        sdkp->protection_type = type;
 
        switch (type) {
-       case SD_DIF_TYPE0_PROTECTION:
        case SD_DIF_TYPE1_PROTECTION:
        case SD_DIF_TYPE3_PROTECTION:
                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;
+               sd_printk(KERN_ERR, sdkp, "formatted with unsupported " \
+                         "protection type %u. Disabling disk!\n", type);
+               sdkp->capacity = 0;
+               return;
        }
 
-       return;
-
-disable:
-       sdkp->capacity = 0;
+       if (scsi_host_dif_capable(sdp->host, type))
+               sd_printk(KERN_NOTICE, sdkp,
+                         "Enabling DIF Type %u protection\n", type);
+       else
+               sd_printk(KERN_NOTICE, sdkp,
+                         "Disabling DIF Type %u protection\n", type);
 }
 
 static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,

diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 8474b5b..ce1f5f8 100644 (file)
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -101,16 +101,12 @@ struct sd_dif_tuple {
 
 #ifdef CONFIG_BLK_DEV_INTEGRITY
 
-extern void sd_dif_op(struct scsi_cmnd *, unsigned int, unsigned int, unsigned int);
 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 */
 
-static inline void sd_dif_op(struct scsi_cmnd *cmd, unsigned int a, unsigned int b, unsigned int c)
-{
-}
 static inline void sd_dif_config_host(struct scsi_disk *disk)
 {
 }

diff --git a/drivers/scsi/sd_dif.c b/drivers/scsi/sd_dif.c
index 84224dd..88da977 100644 (file)
--- a/drivers/scsi/sd_dif.c
+++ b/drivers/scsi/sd_dif.c
@@ -320,15 +320,6 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
                dif = 0; dix = 1;
        }
 
-       if (type) {
-               if (dif)
-                       sd_printk(KERN_NOTICE, sdkp,
-                                 "Enabling DIF Type %d protection\n", type);
-               else
-                       sd_printk(KERN_NOTICE, sdkp,
-                                 "Disabling DIF Type %d protection\n", type);
-       }
-
        if (!dix)
                return;
 
@@ -360,50 +351,6 @@ void sd_dif_config_host(struct scsi_disk *sdkp)
 }
 
 /*
- * DIF DMA operation magic decoder ring.
- */
-void sd_dif_op(struct scsi_cmnd *scmd, unsigned int dif, unsigned int dix, unsigned int type)
-{
-       int prot_op;
-
-       prot_op = SCSI_PROT_NORMAL;
-
-       BUG_ON(dif && (scmd->cmnd[0] == READ_6 || scmd->cmnd[0] == WRITE_6));
-
-       switch (scmd->cmnd[0]) {
-       case READ_6:
-       case READ_10:
-       case READ_12:
-       case READ_16:
-               if (dif && dix)
-                       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_6:
-       case WRITE_10:
-       case WRITE_12:
-       case WRITE_16:
-               if (dif && dix)
-                       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);
-       if (dif)
-               scsi_set_prot_type(scmd, type);
-}
-
-/*
  * 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

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index b62a097..6e728b1 100644 (file)
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -798,9 +798,15 @@ static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
 {
        switch (target_type) {
-       case 1: return shost->prot_capabilities & SHOST_DIF_TYPE1_PROTECTION;
-       case 2: return shost->prot_capabilities & SHOST_DIF_TYPE2_PROTECTION;
-       case 3: return shost->prot_capabilities & SHOST_DIF_TYPE3_PROTECTION;
+       case 1:
+               if (shost->prot_capabilities & SHOST_DIF_TYPE1_PROTECTION)
+                       return target_type;
+       case 2:
+               if (shost->prot_capabilities & SHOST_DIF_TYPE2_PROTECTION)
+                       return target_type;
+       case 3:
+               if (shost->prot_capabilities & SHOST_DIF_TYPE3_PROTECTION)
+                       return target_type;
        }
 
        return 0;
@@ -808,13 +814,14 @@ static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsign
 
 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
 {
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
        switch (target_type) {
        case 0: return shost->prot_capabilities & SHOST_DIX_TYPE0_PROTECTION;
        case 1: return shost->prot_capabilities & SHOST_DIX_TYPE1_PROTECTION;
        case 2: return shost->prot_capabilities & SHOST_DIX_TYPE2_PROTECTION;
        case 3: return shost->prot_capabilities & SHOST_DIX_TYPE3_PROTECTION;
        }
-
+#endif
        return 0;
 }