[PATCH 6/7] sd: support multi-range TRIM for ATA disks

[Christoph Hellwig]

Almost the same scheme as the older multi-range support for NVMe.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/scsi/sd.c | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cc8684818305..c18fe9ff1f8f 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -643,7 +643,7 @@ static void sd_config_discard(struct scsi_disk *sdkp, 
unsigned int mode)
 {
        struct request_queue *q = sdkp->disk->queue;
        unsigned int logical_block_size = sdkp->device->sector_size;
-       unsigned int max_blocks = 0;
+       unsigned int max_blocks = 0, max_ranges = 0, max_range_size = 0;
 
        q->limits.discard_zeroes_data = 0;
 
@@ -698,13 +698,19 @@ static void sd_config_discard(struct scsi_disk *sdkp, 
unsigned int mode)
                break;
 
        case SD_LBP_ATA_TRIM:
-               max_blocks = 65535 * (512 / sizeof(__le64));
+               max_ranges = 512 / sizeof(__le64);
+               max_range_size = USHRT_MAX;
+               max_blocks = max_ranges * max_range_size;
                if (sdkp->device->ata_trim_zeroes_data)
                        q->limits.discard_zeroes_data = 1;
                break;
        }
 
        blk_queue_max_discard_sectors(q, max_blocks * (logical_block_size >> 
9));
+       if (max_ranges)
+               blk_queue_max_discard_segments(q, max_ranges);
+       if (max_range_size)
+               blk_queue_max_discard_segment_size(q, max_range_size);
        queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 }
 
@@ -805,9 +811,9 @@ static int sd_setup_ata_trim_cmnd(struct scsi_cmnd *cmd)
 {
        struct scsi_device *sdp = cmd->device;
        struct request *rq = cmd->request;
-       u64 sector = blk_rq_pos(rq) >> (ilog2(sdp->sector_size) - 9);
-       u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
-       u32 data_len = sdp->sector_size, i;
+       u32 sector_shift = ilog2(sdp->sector_size);
+       u32 data_len = sdp->sector_size, i = 0;
+       struct bio *bio;
        __le64 *buf;
 
        rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
@@ -826,14 +832,21 @@ static int sd_setup_ata_trim_cmnd(struct scsi_cmnd *cmd)
        cmd->cmnd[8] = data_len;
 
        buf = page_address(rq->special_vec.bv_page);
-       for (i = 0; i < (data_len >> 3); i++) {
-               u64 n = min(nr_sectors, 0xffffu);
+       __rq_for_each_bio(bio, rq) {
+               u64 sector = bio->bi_iter.bi_sector >> (sector_shift - 9);
+               u32 nr_sectors = bio->bi_iter.bi_size >> sector_shift;
 
-               buf[i] = cpu_to_le64(sector | (n << 48));
-               if (nr_sectors <= 0xffff)
-                       break;
-               sector += 0xffff;
-               nr_sectors -= 0xffff;
+               do {
+                       u64 n = min(nr_sectors, 0xffffu);
+
+                       buf[i] = cpu_to_le64(sector | (n << 48));
+                       if (nr_sectors <= 0xffff)
+                               break;
+                       sector += 0xffff;
+                       nr_sectors -= 0xffff;
+                       i++;
+
+               } while (!WARN_ON_ONCE(i >= data_len >> 3));
        }
 
        cmd->allowed = SD_MAX_RETRIES;
-- 
2.11.0