Add support of iouring iopoll interface in scsi_debug. This feature requires shared hosttag support in kernel and driver. Signed-off-by: Kashyap Desai Acked-by: Douglas Gilbert Tested-by: Douglas Gilbert Reviewed-by: Hannes Reinecke Cc: dgilbert@interlog.com Cc: linux-block@vger.kernel.org --- drivers/scsi/scsi_debug.c | 130 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index d1b0cbe1b5f1..746eec521f79 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -829,6 +829,7 @@ static int sdeb_zbc_max_open = DEF_ZBC_MAX_OPEN_ZONES; static int sdeb_zbc_nr_conv = DEF_ZBC_NR_CONV_ZONES; static int submit_queues = DEF_SUBMIT_QUEUES; /* > 1 for multi-queue (mq) */ +static int poll_queues; /* iouring iopoll interface.*/ static struct sdebug_queue *sdebug_q_arr; /* ptr to array of submit queues */ static DEFINE_RWLOCK(atomic_rw); @@ -5432,6 +5433,14 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, cmnd->host_scribble = (unsigned char *)sqcp; sd_dp = sqcp->sd_dp; spin_unlock_irqrestore(&sqp->qc_lock, iflags); + + /* Do not complete IO from default completion path. + * Let it to be on queue. + * Completion should happen from mq_poll interface. + */ + if ((sqp - sdebug_q_arr) >= (submit_queues - poll_queues)) + return 0; + if (!sd_dp) { sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC); if (!sd_dp) { @@ -5615,6 +5624,7 @@ module_param_named(sector_size, sdebug_sector_size, int, S_IRUGO); module_param_named(statistics, sdebug_statistics, bool, S_IRUGO | S_IWUSR); module_param_named(strict, sdebug_strict, bool, S_IRUGO | S_IWUSR); module_param_named(submit_queues, submit_queues, int, S_IRUGO); +module_param_named(poll_queues, poll_queues, int, S_IRUGO); module_param_named(tur_ms_to_ready, sdeb_tur_ms_to_ready, int, S_IRUGO); module_param_named(unmap_alignment, sdebug_unmap_alignment, int, S_IRUGO); module_param_named(unmap_granularity, sdebug_unmap_granularity, int, S_IRUGO); @@ -5677,6 +5687,7 @@ MODULE_PARM_DESC(opt_xferlen_exp, "optimal transfer length granularity exponent MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)"); MODULE_PARM_DESC(per_host_store, "If set, next positive add_host will get new store (def=0)"); MODULE_PARM_DESC(physblk_exp, "physical block exponent (def=0)"); +MODULE_PARM_DESC(poll_queues, "support for iouring iopoll queues (1 to max(submit_queues - 1)"); MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])"); MODULE_PARM_DESC(random, "If set, uniformly randomize command duration between 0 and delay_in_ns"); MODULE_PARM_DESC(removable, "claim to have removable media (def=0)"); @@ -7201,6 +7212,104 @@ static int resp_not_ready(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) return check_condition_result; } +static int sdebug_map_queues(struct Scsi_Host *shost) +{ + int i, qoff; + + if (shost->nr_hw_queues == 1) + return 0; + + for (i = 0, qoff = 0; i < HCTX_MAX_TYPES; i++) { + struct blk_mq_queue_map *map = &shost->tag_set.map[i]; + + map->nr_queues = 0; + + if (i == HCTX_TYPE_DEFAULT) + map->nr_queues = submit_queues - poll_queues; + else if (i == HCTX_TYPE_POLL) + map->nr_queues = poll_queues; + + if (!map->nr_queues) { + BUG_ON(i == HCTX_TYPE_DEFAULT); + continue; + } + + map->queue_offset = qoff; + blk_mq_map_queues(map); + + qoff += map->nr_queues; + } + + return 0; + +} + +static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num) +{ + int qc_idx; + int retiring = 0; + unsigned long iflags; + struct sdebug_queue *sqp; + struct sdebug_queued_cmd *sqcp; + struct scsi_cmnd *scp; + struct sdebug_dev_info *devip; + int num_entries = 0; + + sqp = sdebug_q_arr + queue_num; + + do { + spin_lock_irqsave(&sqp->qc_lock, iflags); + qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue); + if (unlikely((qc_idx < 0) || (qc_idx >= sdebug_max_queue))) + goto out; + + sqcp = &sqp->qc_arr[qc_idx]; + scp = sqcp->a_cmnd; + if (unlikely(scp == NULL)) { + pr_err("scp is NULL, queue_num=%d, qc_idx=%d from %s\n", + queue_num, qc_idx, __func__); + goto out; + } + devip = (struct sdebug_dev_info *)scp->device->hostdata; + if (likely(devip)) + atomic_dec(&devip->num_in_q); + else + pr_err("devip=NULL from %s\n", __func__); + if (unlikely(atomic_read(&retired_max_queue) > 0)) + retiring = 1; + + sqcp->a_cmnd = NULL; + if (unlikely(!test_and_clear_bit(qc_idx, sqp->in_use_bm))) { + pr_err("Unexpected completion sqp %p queue_num=%d qc_idx=%d from %s\n", + sqp, queue_num, qc_idx, __func__); + goto out; + } + + if (unlikely(retiring)) { /* user has reduced max_queue */ + int k, retval; + + retval = atomic_read(&retired_max_queue); + if (qc_idx >= retval) { + pr_err("index %d too large\n", retval); + goto out; + } + k = find_last_bit(sqp->in_use_bm, retval); + if ((k < sdebug_max_queue) || (k == retval)) + atomic_set(&retired_max_queue, 0); + else + atomic_set(&retired_max_queue, k + 1); + } + spin_unlock_irqrestore(&sqp->qc_lock, iflags); + scp->scsi_done(scp); /* callback to mid level */ + num_entries++; + } while (1); + +out: + spin_unlock_irqrestore(&sqp->qc_lock, iflags); + return num_entries; +} + + static int scsi_debug_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scp) { @@ -7380,6 +7489,8 @@ static struct scsi_host_template sdebug_driver_template = { .ioctl = scsi_debug_ioctl, .queuecommand = scsi_debug_queuecommand, .change_queue_depth = sdebug_change_qdepth, + .map_queues = sdebug_map_queues, + .mq_poll = sdebug_blk_mq_poll, .eh_abort_handler = scsi_debug_abort, .eh_device_reset_handler = scsi_debug_device_reset, .eh_target_reset_handler = scsi_debug_target_reset, @@ -7427,6 +7538,25 @@ static int sdebug_driver_probe(struct device *dev) if (sdebug_host_max_queue) hpnt->host_tagset = 1; + /* poll queues are possible for nr_hw_queues > 1 */ + if (hpnt->nr_hw_queues == 1 || (poll_queues < 1)) { + pr_warn("%s: trim poll_queues to 0. poll_q/nr_hw = (%d/%d)\n", + my_name, poll_queues, hpnt->nr_hw_queues); + poll_queues = 0; + } + + /* + * Poll queues don't need interrupts, but we need at least one I/O queue + * left over for non-polled I/O. + * If condition not met, trim poll_queues to 1 (just for simplicity). + */ + if (poll_queues >= submit_queues) { + pr_warn("%s: trim poll_queues to 1\n", my_name); + poll_queues = 1; + } + if (poll_queues) + hpnt->nr_maps = 3; + sdbg_host->shost = hpnt; *((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host; if ((hpnt->this_id >= 0) && (sdebug_num_tgts > hpnt->this_id)) -- 2.18.1