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[SCSI] hpsa: complete the ioaccel raidmap code

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Load balance across members of a N-way mirror set, and
handle the meta-RAID levels: R10, R50, R60.

Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Scott Teel 2014-02-18 13:56:55 -06:00 committed by James Bottomley
parent 9fb0de2d12
commit 6b80b18fe5
1 changed files with 168 additions and 6 deletions
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174
drivers/scsi/hpsa.c
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@ -423,6 +423,13 @@ static inline int is_logical_dev_addr_mode(unsigned char scsi3addr[])
static const char *raid_label[] = { "0", "4", "1(1+0)", "5", "5+1", "ADG",
"1(ADM)", "UNKNOWN"
};
#define HPSA_RAID_0 0
#define HPSA_RAID_4 1
#define HPSA_RAID_1 2 /* also used for RAID 10 */
#define HPSA_RAID_5 3 /* also used for RAID 50 */
#define HPSA_RAID_51 4
#define HPSA_RAID_6 5 /* also used for RAID 60 */
#define HPSA_RAID_ADM 6 /* also used for RAID 1+0 ADM */
#define RAID_UNKNOWN (ARRAY_SIZE(raid_label) - 1)
static ssize_t raid_level_show(struct device *dev,
@ -2941,6 +2948,31 @@ static int hpsa_scsi_ioaccel_queue_command(struct ctlr_info *h,
cdb, cdb_len, scsi3addr);
}
static void raid_map_helper(struct raid_map_data *map,
int offload_to_mirror, u32 *map_index, u32 *current_group)
{
if (offload_to_mirror == 0) {
/* use physical disk in the first mirrored group. */
*map_index %= map->data_disks_per_row;
return;
}
do {
/* determine mirror group that *map_index indicates */
*current_group = *map_index / map->data_disks_per_row;
if (offload_to_mirror == *current_group)
continue;
if (*current_group < (map->layout_map_count - 1)) {
/* select map index from next group */
*map_index += map->data_disks_per_row;
(*current_group)++;
} else {
/* select map index from first group */
*map_index %= map->data_disks_per_row;
*current_group = 0;
}
} while (offload_to_mirror != *current_group);
}
/*
* Attempt to perform offload RAID mapping for a logical volume I/O.
*/
@ -2959,6 +2991,14 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
u64 first_row, last_row;
u32 first_row_offset, last_row_offset;
u32 first_column, last_column;
u64 r0_first_row, r0_last_row;
u32 r5or6_blocks_per_row;
u64 r5or6_first_row, r5or6_last_row;
u32 r5or6_first_row_offset, r5or6_last_row_offset;
u32 r5or6_first_column, r5or6_last_column;
u32 total_disks_per_row;
u32 stripesize;
u32 first_group, last_group, current_group;
u32 map_row;
u32 disk_handle;
u64 disk_block;
@ -2968,6 +3008,7 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
#if BITS_PER_LONG == 32
u64 tmpdiv;
#endif
int offload_to_mirror;
BUG_ON(!(dev->offload_config && dev->offload_enabled));
@ -3070,19 +3111,140 @@ static int hpsa_scsi_ioaccel_raid_map(struct ctlr_info *h,
return IO_ACCEL_INELIGIBLE;
/* proceeding with driver mapping */
total_disks_per_row = map->data_disks_per_row +
map->metadata_disks_per_row;
map_row = ((u32)(first_row >> map->parity_rotation_shift)) %
map->row_cnt;
map_index = (map_row * (map->data_disks_per_row +
map->metadata_disks_per_row)) + first_column;
if (dev->raid_level == 2) {
/* simple round-robin balancing of RAID 1+0 reads across
* primary and mirror members. this is appropriate for SSD
* but not optimal for HDD.
map_index = (map_row * total_disks_per_row) + first_column;
switch (dev->raid_level) {
case HPSA_RAID_0:
break; /* nothing special to do */
case HPSA_RAID_1:
/* Handles load balance across RAID 1 members.
* (2-drive R1 and R10 with even # of drives.)
* Appropriate for SSDs, not optimal for HDDs
*/
BUG_ON(map->layout_map_count != 2);
if (dev->offload_to_mirror)
map_index += map->data_disks_per_row;
dev->offload_to_mirror = !dev->offload_to_mirror;
break;
case HPSA_RAID_ADM:
/* Handles N-way mirrors (R1-ADM)
* and R10 with # of drives divisible by 3.)
*/
BUG_ON(map->layout_map_count != 3);
offload_to_mirror = dev->offload_to_mirror;
raid_map_helper(map, offload_to_mirror,
&map_index, &current_group);
/* set mirror group to use next time */
offload_to_mirror =
(offload_to_mirror >= map->layout_map_count - 1)
? 0 : offload_to_mirror + 1;
/* FIXME: remove after debug/dev */
BUG_ON(offload_to_mirror >= map->layout_map_count);
dev_warn(&h->pdev->dev,
"DEBUG: Using physical disk map index %d from mirror group %d\n",
map_index, offload_to_mirror);
dev->offload_to_mirror = offload_to_mirror;
/* Avoid direct use of dev->offload_to_mirror within this
* function since multiple threads might simultaneously
* increment it beyond the range of dev->layout_map_count -1.
*/
break;
case HPSA_RAID_5:
case HPSA_RAID_6:
if (map->layout_map_count <= 1)
break;
/* Verify first and last block are in same RAID group */
r5or6_blocks_per_row =
map->strip_size * map->data_disks_per_row;
BUG_ON(r5or6_blocks_per_row == 0);
stripesize = r5or6_blocks_per_row * map->layout_map_count;
#if BITS_PER_LONG == 32
tmpdiv = first_block;
first_group = do_div(tmpdiv, stripesize);
tmpdiv = first_group;
(void) do_div(tmpdiv, r5or6_blocks_per_row);
first_group = tmpdiv;
tmpdiv = last_block;
last_group = do_div(tmpdiv, stripesize);
tmpdiv = last_group;
(void) do_div(tmpdiv, r5or6_blocks_per_row);
last_group = tmpdiv;
#else
first_group = (first_block % stripesize) / r5or6_blocks_per_row;
last_group = (last_block % stripesize) / r5or6_blocks_per_row;
if (first_group != last_group)
#endif
return IO_ACCEL_INELIGIBLE;
/* Verify request is in a single row of RAID 5/6 */
#if BITS_PER_LONG == 32
tmpdiv = first_block;
(void) do_div(tmpdiv, stripesize);
first_row = r5or6_first_row = r0_first_row = tmpdiv;
tmpdiv = last_block;
(void) do_div(tmpdiv, stripesize);
r5or6_last_row = r0_last_row = tmpdiv;
#else
first_row = r5or6_first_row = r0_first_row =
first_block / stripesize;
r5or6_last_row = r0_last_row = last_block / stripesize;
#endif
if (r5or6_first_row != r5or6_last_row)
return IO_ACCEL_INELIGIBLE;
/* Verify request is in a single column */
#if BITS_PER_LONG == 32
tmpdiv = first_block;
first_row_offset = do_div(tmpdiv, stripesize);
tmpdiv = first_row_offset;
first_row_offset = (u32) do_div(tmpdiv, r5or6_blocks_per_row);
r5or6_first_row_offset = first_row_offset;
tmpdiv = last_block;
r5or6_last_row_offset = do_div(tmpdiv, stripesize);
tmpdiv = r5or6_last_row_offset;
r5or6_last_row_offset = do_div(tmpdiv, r5or6_blocks_per_row);
tmpdiv = r5or6_first_row_offset;
(void) do_div(tmpdiv, map->strip_size);
first_column = r5or6_first_column = tmpdiv;
tmpdiv = r5or6_last_row_offset;
(void) do_div(tmpdiv, map->strip_size);
r5or6_last_column = tmpdiv;
#else
first_row_offset = r5or6_first_row_offset =
(u32)((first_block % stripesize) %
r5or6_blocks_per_row);
r5or6_last_row_offset =
(u32)((last_block % stripesize) %
r5or6_blocks_per_row);
first_column = r5or6_first_column =
r5or6_first_row_offset / map->strip_size;
r5or6_last_column =
r5or6_last_row_offset / map->strip_size;
#endif
if (r5or6_first_column != r5or6_last_column)
return IO_ACCEL_INELIGIBLE;
/* Request is eligible */
map_row = ((u32)(first_row >> map->parity_rotation_shift)) %
map->row_cnt;
map_index = (first_group *
(map->row_cnt * total_disks_per_row)) +
(map_row * total_disks_per_row) + first_column;
break;
default:
return IO_ACCEL_INELIGIBLE;
}
disk_handle = dd[map_index].ioaccel_handle;
disk_block = map->disk_starting_blk + (first_row * map->strip_size) +
(first_row_offset - (first_column * map->strip_size));