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path: root/drivers/scsi/virtio_scsi.c
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Diffstat (limited to 'drivers/scsi/virtio_scsi.c')
-rw-r--r--drivers/scsi/virtio_scsi.c129
1 files changed, 16 insertions, 113 deletions
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 7c28e8d4955a..45d04631888a 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -91,9 +91,6 @@ struct virtio_scsi_vq {
struct virtio_scsi_target_state {
seqcount_t tgt_seq;
- /* Count of outstanding requests. */
- atomic_t reqs;
-
/* Currently active virtqueue for requests sent to this target. */
struct virtio_scsi_vq *req_vq;
};
@@ -152,8 +149,6 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
struct virtio_scsi_cmd *cmd = buf;
struct scsi_cmnd *sc = cmd->sc;
struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
- struct virtio_scsi_target_state *tgt =
- scsi_target(sc->device)->hostdata;
dev_dbg(&sc->device->sdev_gendev,
"cmd %p response %u status %#02x sense_len %u\n",
@@ -210,8 +205,6 @@ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
}
sc->scsi_done(sc);
-
- atomic_dec(&tgt->reqs);
}
static void virtscsi_vq_done(struct virtio_scsi *vscsi,
@@ -529,11 +522,20 @@ static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev,
}
#endif
-static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
- struct virtio_scsi_vq *req_vq,
+static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
+ struct scsi_cmnd *sc)
+{
+ u32 tag = blk_mq_unique_tag(sc->request);
+ u16 hwq = blk_mq_unique_tag_to_hwq(tag);
+
+ return &vscsi->req_vqs[hwq];
+}
+
+static int virtscsi_queuecommand(struct Scsi_Host *shost,
struct scsi_cmnd *sc)
{
- struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+ struct virtio_scsi *vscsi = shost_priv(shost);
+ struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc);
struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc);
unsigned long flags;
int req_size;
@@ -576,79 +578,6 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
return 0;
}
-static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
- struct scsi_cmnd *sc)
-{
- struct virtio_scsi *vscsi = shost_priv(sh);
- struct virtio_scsi_target_state *tgt =
- scsi_target(sc->device)->hostdata;
-
- atomic_inc(&tgt->reqs);
- return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc);
-}
-
-static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi,
- struct scsi_cmnd *sc)
-{
- u32 tag = blk_mq_unique_tag(sc->request);
- u16 hwq = blk_mq_unique_tag_to_hwq(tag);
-
- return &vscsi->req_vqs[hwq];
-}
-
-static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
- struct virtio_scsi_target_state *tgt)
-{
- struct virtio_scsi_vq *vq;
- unsigned long flags;
- u32 queue_num;
-
- local_irq_save(flags);
- if (atomic_inc_return(&tgt->reqs) > 1) {
- unsigned long seq;
-
- do {
- seq = read_seqcount_begin(&tgt->tgt_seq);
- vq = tgt->req_vq;
- } while (read_seqcount_retry(&tgt->tgt_seq, seq));
- } else {
- /* no writes can be concurrent because of atomic_t */
- write_seqcount_begin(&tgt->tgt_seq);
-
- /* keep previous req_vq if a reader just arrived */
- if (unlikely(atomic_read(&tgt->reqs) > 1)) {
- vq = tgt->req_vq;
- goto unlock;
- }
-
- queue_num = smp_processor_id();
- while (unlikely(queue_num >= vscsi->num_queues))
- queue_num -= vscsi->num_queues;
- tgt->req_vq = vq = &vscsi->req_vqs[queue_num];
- unlock:
- write_seqcount_end(&tgt->tgt_seq);
- }
- local_irq_restore(flags);
-
- return vq;
-}
-
-static int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
- struct scsi_cmnd *sc)
-{
- struct virtio_scsi *vscsi = shost_priv(sh);
- struct virtio_scsi_target_state *tgt =
- scsi_target(sc->device)->hostdata;
- struct virtio_scsi_vq *req_vq;
-
- if (shost_use_blk_mq(sh))
- req_vq = virtscsi_pick_vq_mq(vscsi, sc);
- else
- req_vq = virtscsi_pick_vq(vscsi, tgt);
-
- return virtscsi_queuecommand(vscsi, req_vq, sc);
-}
-
static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
{
DECLARE_COMPLETION_ONSTACK(comp);
@@ -775,7 +704,6 @@ static int virtscsi_target_alloc(struct scsi_target *starget)
return -ENOMEM;
seqcount_init(&tgt->tgt_seq);
- atomic_set(&tgt->reqs, 0);
tgt->req_vq = &vscsi->req_vqs[0];
starget->hostdata = tgt;
@@ -805,33 +733,13 @@ static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd)
return BLK_EH_RESET_TIMER;
}
-static struct scsi_host_template virtscsi_host_template_single = {
- .module = THIS_MODULE,
- .name = "Virtio SCSI HBA",
- .proc_name = "virtio_scsi",
- .this_id = -1,
- .cmd_size = sizeof(struct virtio_scsi_cmd),
- .queuecommand = virtscsi_queuecommand_single,
- .change_queue_depth = virtscsi_change_queue_depth,
- .eh_abort_handler = virtscsi_abort,
- .eh_device_reset_handler = virtscsi_device_reset,
- .eh_timed_out = virtscsi_eh_timed_out,
- .slave_alloc = virtscsi_device_alloc,
-
- .dma_boundary = UINT_MAX,
- .use_clustering = ENABLE_CLUSTERING,
- .target_alloc = virtscsi_target_alloc,
- .target_destroy = virtscsi_target_destroy,
- .track_queue_depth = 1,
-};
-
-static struct scsi_host_template virtscsi_host_template_multi = {
+static struct scsi_host_template virtscsi_host_template = {
.module = THIS_MODULE,
.name = "Virtio SCSI HBA",
.proc_name = "virtio_scsi",
.this_id = -1,
.cmd_size = sizeof(struct virtio_scsi_cmd),
- .queuecommand = virtscsi_queuecommand_multi,
+ .queuecommand = virtscsi_queuecommand,
.change_queue_depth = virtscsi_change_queue_depth,
.eh_abort_handler = virtscsi_abort,
.eh_device_reset_handler = virtscsi_device_reset,
@@ -844,6 +752,7 @@ static struct scsi_host_template virtscsi_host_template_multi = {
.target_destroy = virtscsi_target_destroy,
.map_queues = virtscsi_map_queues,
.track_queue_depth = 1,
+ .force_blk_mq = 1,
};
#define virtscsi_config_get(vdev, fld) \
@@ -936,7 +845,6 @@ static int virtscsi_probe(struct virtio_device *vdev)
u32 sg_elems, num_targets;
u32 cmd_per_lun;
u32 num_queues;
- struct scsi_host_template *hostt;
if (!vdev->config->get) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
@@ -949,12 +857,7 @@ static int virtscsi_probe(struct virtio_device *vdev)
num_targets = virtscsi_config_get(vdev, max_target) + 1;
- if (num_queues == 1)
- hostt = &virtscsi_host_template_single;
- else
- hostt = &virtscsi_host_template_multi;
-
- shost = scsi_host_alloc(hostt,
+ shost = scsi_host_alloc(&virtscsi_host_template,
sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
if (!shost)
return -ENOMEM;