[S390] dasd: Add support for raw ECKD access.

Normal I/O operations through the DASD device driver give only access
to the data fields of an ECKD device even for track based I/O.
This patch extends the DASD device driver to give access to whole
ECKD tracks including count, key and data fields.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 20 insertions, 3 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 82d9ce36bd0b..4e266f43332d 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -369,6 +369,11 @@ dasd_state_ready_to_online(struct dasd_device * device)
         device->state = DASD_STATE_ONLINE;
         if (device->block) {
                 dasd_schedule_block_bh(device->block);
+                if ((device->features & DASD_FEATURE_USERAW)) {
+                        disk = device->block->gdp;
+                        kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+                        return 0;
+                }
                 disk = device->block->bdev->bd_disk;
                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
                 while ((part = disk_part_iter_next(&piter)))
@@ -394,7 +399,7 @@ static int dasd_state_online_to_ready(struct dasd_device *device)
                         return rc;
         }
         device->state = DASD_STATE_READY;
-        if (device->block) {
+        if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
                 disk = device->block->bdev->bd_disk;
                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
                 while ((part = disk_part_iter_next(&piter)))
@@ -2258,8 +2263,20 @@ static void dasd_setup_queue(struct dasd_block *block)
 {
         int max;
 
-        blk_queue_logical_block_size(block->request_queue, block->bp_block);
-        max = block->base->discipline->max_blocks << block->s2b_shift;
+        if (block->base->features & DASD_FEATURE_USERAW) {
+                /*
+                 * the max_blocks value for raw_track access is 256
+                 * it is higher than the native ECKD value because we
+                 * only need one ccw per track
+                 * so the max_hw_sectors are
+                 * 2048 x 512B = 1024kB = 16 tracks
+                 */
+                max = 2048;
+        } else {
+                max = block->base->discipline->max_blocks << block->s2b_shift;
+        }
+        blk_queue_logical_block_size(block->request_queue,
+                                     block->bp_block);
         blk_queue_max_hw_sectors(block->request_queue, max);
         blk_queue_max_segments(block->request_queue, -1L);
         /* with page sized segments we can translate each segement into