sd: Physical block size and alignment support

Extract physical block size and lowest aligned LBA from READ
CAPACITY(16) response and adjust queue parameters.

Report physical block size and alignment when applicable.

[jejb: fix up trailing whitespace]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 22 insertions, 2 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 878b17a9af30..a86064b6458d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1307,6 +1307,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
         int sense_valid = 0;
         int the_result;
         int retries = 3;
+        unsigned int alignment;
         unsigned long long lba;
         unsigned sector_size;
 
@@ -1358,6 +1359,16 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
                 return -EOVERFLOW;
         }
 
+        /* Logical blocks per physical block exponent */
+        sdkp->hw_sector_size = (1 << (buffer[13] & 0xf)) * sector_size;
+
+        /* Lowest aligned logical block */
+        alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
+        blk_queue_alignment_offset(sdp->request_queue, alignment);
+        if (alignment && sdkp->first_scan)
+                sd_printk(KERN_NOTICE, sdkp,
+                          "physical block alignment offset: %u\n", alignment);
+
         sdkp->capacity = lba + 1;
         return sector_size;
 }
@@ -1409,6 +1420,7 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
         }
 
         sdkp->capacity = lba + 1;
+        sdkp->hw_sector_size = sector_size;
         return sector_size;
 }
 
@@ -1521,11 +1533,17 @@ got_data:
                 string_get_size(sz, STRING_UNITS_10, cap_str_10,
                                 sizeof(cap_str_10));
 
-                if (sdkp->first_scan || old_capacity != sdkp->capacity)
+                if (sdkp->first_scan || old_capacity != sdkp->capacity) {
                         sd_printk(KERN_NOTICE, sdkp,
-                                  "%llu %d-byte hardware sectors: (%s/%s)\n",
+                                  "%llu %d-byte logical blocks: (%s/%s)\n",
                                   (unsigned long long)sdkp->capacity,
                                   sector_size, cap_str_10, cap_str_2);
+
+                        if (sdkp->hw_sector_size != sector_size)
+                                sd_printk(KERN_NOTICE, sdkp,
+                                          "%u-byte physical blocks\n",
+                                          sdkp->hw_sector_size);
+                }
         }
 
         /* Rescale capacity to 512-byte units */
@@ -1538,6 +1556,7 @@ got_data:
         else if (sector_size == 256)
                 sdkp->capacity >>= 1;
 
+        blk_queue_physical_block_size(sdp->request_queue, sdkp->hw_sector_size);
         sdkp->device->sector_size = sector_size;
 }
 
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 708778cf5f06..8474b5bad3fe 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -45,6 +45,7 @@ struct scsi_disk {
         unsigned int    openers;        /* protected by BKL for now, yuck */
         sector_t        capacity;       /* size in 512-byte sectors */
         u32             index;
+        unsigned short  hw_sector_size;
         u8              media_present;
         u8              write_prot;
         u8              protection_type;/* Data Integrity Field */