Add CQE support to the block driver, including:
        - optionally using DCMD for flush requests
        - "manually" issuing discard requests
        - issuing read / write requests to the CQE
        - supporting block-layer timeouts
        - handling recovery
        - supporting re-tuning

CQE offers 25% - 50% better random multi-threaded I/O.  There is a slight
(e.g. 2%) drop in sequential read speed but no observable change to sequential
write.

CQE automatically sends the commands to complete requests.  However it only
supports reads / writes and so-called "direct commands" (DCMD).  Furthermore
DCMD is limited to one command at a time, but discards require 3 commands.
That makes issuing discards through CQE very awkward, but some CQE's don't
support DCMD anyway.  So for discards, the existing non-CQE approach is
taken, where the mmc core code issues the 3 commands one at a time i.e.
mmc_erase(). Where DCMD is used, is for issuing flushes.

Signed-off-by: Adrian Hunter <adrian.hun...@intel.com>
---
 drivers/mmc/core/block.c | 217 +++++++++++++++++++++++++-
 drivers/mmc/core/block.h |   7 +
 drivers/mmc/core/queue.c | 385 ++++++++++++++++++++++++++++++++++++++++++++---
 drivers/mmc/core/queue.h |  46 +++++-
 4 files changed, 626 insertions(+), 29 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 2424c7360687..fd867b6c1f77 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -109,6 +109,7 @@ struct mmc_blk_data {
 #define MMC_BLK_WRITE          BIT(1)
 #define MMC_BLK_DISCARD                BIT(2)
 #define MMC_BLK_SECDISCARD     BIT(3)
+#define MMC_BLK_CQE_RECOVERY   BIT(4)
 
        /*
         * Only set in main mmc_blk_data associated
@@ -1266,7 +1267,10 @@ static void mmc_blk_issue_discard_rq(struct mmc_queue 
*mq, struct request *req)
        else
                mmc_blk_reset_success(md, type);
 fail:
-       blk_end_request(req, status, blk_rq_bytes(req));
+       if (req->mq_ctx)
+               blk_mq_end_request(req, status);
+       else
+               blk_end_request(req, status, blk_rq_bytes(req));
 }
 
 static void mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
@@ -1336,7 +1340,10 @@ static void mmc_blk_issue_secdiscard_rq(struct mmc_queue 
*mq,
        if (!err)
                mmc_blk_reset_success(md, type);
 out:
-       blk_end_request(req, status, blk_rq_bytes(req));
+       if (req->mq_ctx)
+               blk_mq_end_request(req, status);
+       else
+               blk_end_request(req, status, blk_rq_bytes(req));
 }
 
 static void mmc_blk_issue_flush(struct mmc_queue *mq, struct request *req)
@@ -1346,7 +1353,10 @@ static void mmc_blk_issue_flush(struct mmc_queue *mq, 
struct request *req)
        int ret = 0;
 
        ret = mmc_flush_cache(card);
-       blk_end_request_all(req, ret ? BLK_STS_IOERR : BLK_STS_OK);
+       if (req->mq_ctx)
+               blk_mq_end_request(req, ret ? BLK_STS_IOERR : BLK_STS_OK);
+       else
+               blk_end_request_all(req, ret ? BLK_STS_IOERR : BLK_STS_OK);
 }
 
 /*
@@ -1659,6 +1669,205 @@ static void mmc_blk_data_prep(struct mmc_queue *mq, 
struct mmc_queue_req *mqrq,
                *do_data_tag_p = do_data_tag;
 }
 
+#define MMC_CQE_RETRIES 2
+
+void mmc_blk_cqe_complete_rq(struct request *req)
+{
+       struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+       struct mmc_request *mrq = &mqrq->brq.mrq;
+       struct request_queue *q = req->q;
+       struct mmc_queue *mq = q->queuedata;
+       struct mmc_host *host = mq->card->host;
+       unsigned long flags;
+       bool put_card;
+       int err;
+
+       mmc_cqe_post_req(host, mrq);
+
+       if (mrq->cmd && mrq->cmd->error)
+               err = mrq->cmd->error;
+       else if (mrq->data && mrq->data->error)
+               err = mrq->data->error;
+       else
+               err = 0;
+
+       if (err) {
+               if (mqrq->retries++ < MMC_CQE_RETRIES)
+                       blk_mq_requeue_request(req, true);
+               else
+                       blk_mq_end_request(req, BLK_STS_IOERR);
+       } else if (mrq->data) {
+               if (blk_update_request(req, BLK_STS_OK, 
mrq->data->bytes_xfered))
+                       blk_mq_requeue_request(req, true);
+               else
+                       __blk_mq_end_request(req, BLK_STS_OK);
+       } else {
+               blk_mq_end_request(req, BLK_STS_OK);
+       }
+
+       spin_lock_irqsave(q->queue_lock, flags);
+
+       mq->cqe_in_flight[mmc_cqe_issue_type(host, req)] -= 1;
+
+       put_card = mmc_cqe_tot_in_flight(mq) == 0;
+
+       mmc_cqe_check_busy(mq);
+
+       spin_unlock_irqrestore(q->queue_lock, flags);
+
+       if (!mq->cqe_busy)
+               blk_mq_run_hw_queues(q, true);
+
+       if (put_card)
+               mmc_ctx_put_card(mq->card, &mq->ctx);
+}
+
+void mmc_blk_cqe_recovery(struct mmc_queue *mq)
+{
+       struct mmc_card *card = mq->card;
+       struct mmc_host *host = card->host;
+       int err;
+
+       mmc_get_card(card);
+
+       pr_debug("%s: CQE recovery start\n", mmc_hostname(host));
+
+       mq->cqe_in_recovery = true;
+
+       err = mmc_cqe_recovery(host);
+       if (err)
+               mmc_blk_reset(mq->blkdata, host, MMC_BLK_CQE_RECOVERY);
+       else
+               mmc_blk_reset_success(mq->blkdata, MMC_BLK_CQE_RECOVERY);
+
+       mq->cqe_in_recovery = false;
+
+       pr_debug("%s: CQE recovery done\n", mmc_hostname(host));
+
+       mmc_put_card(card);
+}
+
+static void mmc_blk_cqe_req_done(struct mmc_request *mrq)
+{
+       struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
+                                                 brq.mrq);
+       struct request *req = mmc_queue_req_to_req(mqrq);
+       struct request_queue *q = req->q;
+       struct mmc_queue *mq = q->queuedata;
+
+       /*
+        * Block layer timeouts race with completions which means the normal
+        * completion path cannot be used during recovery.
+        */
+       if (mq->cqe_in_recovery)
+               mmc_blk_cqe_complete_rq(req);
+       else
+               blk_mq_complete_request(req);
+}
+
+static int mmc_blk_cqe_start_req(struct mmc_host *host, struct mmc_request 
*mrq)
+{
+       mrq->done               = mmc_blk_cqe_req_done;
+       mrq->recovery_notifier  = mmc_cqe_recovery_notifier;
+
+       return mmc_cqe_start_req(host, mrq);
+}
+
+static struct mmc_request *mmc_blk_cqe_prep_dcmd(struct mmc_queue_req *mqrq,
+                                                struct request *req)
+{
+       struct mmc_blk_request *brq = &mqrq->brq;
+
+       memset(brq, 0, sizeof(*brq));
+
+       brq->mrq.cmd = &brq->cmd;
+       brq->mrq.tag = req->tag;
+
+       return &brq->mrq;
+}
+
+static int mmc_blk_cqe_issue_flush(struct mmc_queue *mq, struct request *req)
+{
+       struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+       struct mmc_request *mrq = mmc_blk_cqe_prep_dcmd(mqrq, req);
+
+       mrq->cmd->opcode = MMC_SWITCH;
+       mrq->cmd->arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
+                       (EXT_CSD_FLUSH_CACHE << 16) |
+                       (1 << 8) |
+                       EXT_CSD_CMD_SET_NORMAL;
+       mrq->cmd->flags = MMC_CMD_AC | MMC_RSP_R1B;
+
+       return mmc_blk_cqe_start_req(mq->card->host, mrq);
+}
+
+static int mmc_blk_cqe_issue_rw_rq(struct mmc_queue *mq, struct request *req)
+{
+       struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+
+       mmc_blk_data_prep(mq, mqrq, 0, NULL, NULL);
+
+       return mmc_blk_cqe_start_req(mq->card->host, &mqrq->brq.mrq);
+}
+
+enum mmc_issued mmc_blk_cqe_issue_rq(struct mmc_queue *mq, struct request *req)
+{
+       struct mmc_blk_data *md = mq->blkdata;
+       struct mmc_card *card = md->queue.card;
+       struct mmc_host *host = card->host;
+       int ret;
+
+       ret = mmc_blk_part_switch(card, md->part_type);
+       if (ret)
+               return MMC_REQ_FAILED_TO_START;
+
+       switch (mmc_cqe_issue_type(host, req)) {
+       case MMC_ISSUE_SYNC:
+               ret = host->cqe_ops->cqe_wait_for_idle(host);
+               if (ret)
+                       return MMC_REQ_BUSY;
+               switch (req_op(req)) {
+               case REQ_OP_DRV_IN:
+               case REQ_OP_DRV_OUT:
+                       mmc_blk_issue_drv_op(mq, req);
+                       break;
+               case REQ_OP_DISCARD:
+                       mmc_blk_issue_discard_rq(mq, req);
+                       break;
+               case REQ_OP_SECURE_ERASE:
+                       mmc_blk_issue_secdiscard_rq(mq, req);
+                       break;
+               case REQ_OP_FLUSH:
+                       mmc_blk_issue_flush(mq, req);
+                       break;
+               default:
+                       WARN_ON_ONCE(1);
+                       return MMC_REQ_FAILED_TO_START;
+               }
+               return MMC_REQ_FINISHED;
+       case MMC_ISSUE_DCMD:
+       case MMC_ISSUE_ASYNC:
+               switch (req_op(req)) {
+               case REQ_OP_FLUSH:
+                       ret = mmc_blk_cqe_issue_flush(mq, req);
+                       break;
+               case REQ_OP_READ:
+               case REQ_OP_WRITE:
+                       ret = mmc_blk_cqe_issue_rw_rq(mq, req);
+                       break;
+               default:
+                       WARN_ON_ONCE(1);
+                       ret = -EINVAL;
+               }
+               if (!ret)
+                       return MMC_REQ_STARTED;
+               return ret == -EBUSY ? MMC_REQ_BUSY : MMC_REQ_FAILED_TO_START;
+       default:
+               WARN_ON_ONCE(1);
+               return MMC_REQ_FAILED_TO_START;
+       }
+}
+
 static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
                               struct mmc_card *card,
                               int disable_multi,
@@ -2094,7 +2303,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct 
mmc_card *card,
        INIT_LIST_HEAD(&md->part);
        md->usage = 1;
 
-       ret = mmc_init_queue(&md->queue, card, &md->lock, subname);
+       ret = mmc_init_queue(&md->queue, card, &md->lock, subname, area_type);
        if (ret)
                goto err_putdisk;
 
diff --git a/drivers/mmc/core/block.h b/drivers/mmc/core/block.h
index 860ca7c8df86..d7b3d7008b00 100644
--- a/drivers/mmc/core/block.h
+++ b/drivers/mmc/core/block.h
@@ -6,4 +6,11 @@
 
 void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req);
 
+enum mmc_issued;
+
+enum mmc_issued mmc_blk_cqe_issue_rq(struct mmc_queue *mq,
+                                    struct request *req);
+void mmc_blk_cqe_complete_rq(struct request *rq);
+void mmc_blk_cqe_recovery(struct mmc_queue *mq);
+
 #endif
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 14e9de9c783c..51233324dc45 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -22,6 +22,7 @@
 #include "block.h"
 #include "core.h"
 #include "card.h"
+#include "host.h"
 
 #define MMC_QUEUE_BOUNCESZ     65536
 
@@ -36,10 +37,132 @@ static int mmc_prep_request(struct request_queue *q, 
struct request *req)
                return BLKPREP_KILL;
 
        req->rq_flags |= RQF_DONTPREP;
+       req_to_mmc_queue_req(req)->retries = 0;
 
        return BLKPREP_OK;
 }
 
+static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
+{
+       /* Allow only 1 DCMD at a time */
+       return mq->cqe_in_flight[MMC_ISSUE_DCMD];
+}
+
+void mmc_cqe_check_busy(struct mmc_queue *mq)
+{
+       if ((mq->cqe_busy & MMC_CQE_DCMD_BUSY) && !mmc_cqe_dcmd_busy(mq))
+               mq->cqe_busy &= ~MMC_CQE_DCMD_BUSY;
+
+       mq->cqe_busy &= ~MMC_CQE_QUEUE_FULL;
+}
+
+static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
+{
+       return host->caps2 & MMC_CAP2_CQE_DCMD;
+}
+
+enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
+                                      struct request *req)
+{
+       switch (req_op(req)) {
+       case REQ_OP_DRV_IN:
+       case REQ_OP_DRV_OUT:
+       case REQ_OP_DISCARD:
+       case REQ_OP_SECURE_ERASE:
+               return MMC_ISSUE_SYNC;
+       case REQ_OP_FLUSH:
+               return mmc_cqe_can_dcmd(host) ? MMC_ISSUE_DCMD : MMC_ISSUE_SYNC;
+       default:
+               return MMC_ISSUE_ASYNC;
+       }
+}
+
+static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
+{
+       if (!mq->cqe_recovery_needed) {
+               mq->cqe_recovery_needed = true;
+               schedule_work(&mq->cqe_recovery_work);
+       }
+}
+
+void mmc_cqe_recovery_notifier(struct mmc_request *mrq)
+{
+       struct mmc_queue_req *mqrq = container_of(mrq, struct mmc_queue_req,
+                                                 brq.mrq);
+       struct request *req = mmc_queue_req_to_req(mqrq);
+       struct request_queue *q = req->q;
+       struct mmc_queue *mq = q->queuedata;
+       unsigned long flags;
+
+       spin_lock_irqsave(q->queue_lock, flags);
+       __mmc_cqe_recovery_notifier(mq);
+       spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+static enum blk_eh_timer_return __mmc_cqe_timed_out(struct request *req)
+{
+       struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+       struct mmc_request *mrq = &mqrq->brq.mrq;
+       struct mmc_queue *mq = req->q->queuedata;
+       struct mmc_host *host = mq->card->host;
+       enum mmc_issue_type issue_type = mmc_cqe_issue_type(host, req);
+       bool recovery_needed = false;
+
+       switch (issue_type) {
+       case MMC_ISSUE_ASYNC:
+       case MMC_ISSUE_DCMD:
+               if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) {
+                       if (recovery_needed)
+                               __mmc_cqe_recovery_notifier(mq);
+                       return BLK_EH_RESET_TIMER;
+               }
+               /* No timeout */
+               return BLK_EH_HANDLED;
+       default:
+               /* Timeout is handled by mmc core */
+               return BLK_EH_RESET_TIMER;
+       }
+}
+
+static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req,
+                                                 bool reserved)
+{
+       struct request_queue *q = req->q;
+       struct mmc_queue *mq = q->queuedata;
+       unsigned long flags;
+       int ret;
+
+       spin_lock_irqsave(q->queue_lock, flags);
+
+       if (mq->cqe_recovery_needed)
+               ret = BLK_EH_RESET_TIMER;
+       else
+               ret = __mmc_cqe_timed_out(req);
+
+       spin_unlock_irqrestore(q->queue_lock, flags);
+
+       return ret;
+}
+
+static void mmc_mq_cqe_recovery_handler(struct work_struct *work)
+{
+       struct mmc_queue *mq = container_of(work, struct mmc_queue,
+                                           cqe_recovery_work);
+       struct request_queue *q = mq->queue;
+
+       mmc_ctx_task_claim_host(mq->card->host, &mq->ctx);
+
+       mmc_blk_cqe_recovery(mq);
+
+       spin_lock_irq(q->queue_lock);
+       mq->cqe_recovery_needed = false;
+       spin_unlock_irq(q->queue_lock);
+
+       mmc_ctx_task_release_host(mq->card->host, &mq->ctx);
+
+       blk_mq_run_hw_queues(q, true);
+}
+
 static int mmc_queue_thread(void *d)
 {
        struct mmc_queue *mq = d;
@@ -176,11 +299,10 @@ static unsigned int mmc_queue_calc_bouncesz(struct 
mmc_host *host)
  * @req: the request
  * @gfp: memory allocation policy
  */
-static int mmc_init_request(struct request_queue *q, struct request *req,
-                           gfp_t gfp)
+static int __mmc_init_request(struct mmc_queue *mq, struct request *req,
+                             gfp_t gfp)
 {
        struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
-       struct mmc_queue *mq = q->queuedata;
        struct mmc_card *card = mq->card;
        struct mmc_host *host = card->host;
 
@@ -208,6 +330,12 @@ static int mmc_init_request(struct request_queue *q, 
struct request *req,
        return 0;
 }
 
+static int mmc_init_request(struct request_queue *q, struct request *req,
+                           gfp_t gfp)
+{
+       return __mmc_init_request(q->queuedata, req, gfp);
+}
+
 static void mmc_exit_request(struct request_queue *q, struct request *req)
 {
        struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req);
@@ -223,6 +351,114 @@ static void mmc_exit_request(struct request_queue *q, 
struct request *req)
        mq_rq->sg = NULL;
 }
 
+static int mmc_mq_init_request(struct blk_mq_tag_set *set, struct request *req,
+                              unsigned int hctx_idx, unsigned int numa_node)
+{
+       return __mmc_init_request(set->driver_data, req, GFP_KERNEL);
+}
+
+static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request 
*req,
+                               unsigned int hctx_idx)
+{
+       struct mmc_queue *mq = set->driver_data;
+
+       mmc_exit_request(mq->queue, req);
+}
+
+static blk_status_t mmc_cqe_queue_rq(struct blk_mq_hw_ctx *hctx,
+                                    const struct blk_mq_queue_data *bd)
+{
+       struct request *req = bd->rq;
+       struct request_queue *q = req->q;
+       struct mmc_queue *mq = q->queuedata;
+       struct mmc_card *card = mq->card;
+       struct mmc_host *host = card->host;
+       enum mmc_issue_type issue_type;
+       enum mmc_issued issued;
+       bool get_card, retune_ok;
+       int ret;
+
+       issue_type = mmc_cqe_issue_type(host, req);
+
+       spin_lock_irq(q->queue_lock);
+
+       switch (issue_type) {
+       case MMC_ISSUE_DCMD:
+               if (mmc_cqe_dcmd_busy(mq)) {
+                       mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
+                       spin_unlock_irq(q->queue_lock);
+                       return BLK_STS_RESOURCE;
+               }
+               break;
+       case MMC_ISSUE_ASYNC:
+               break;
+       default:
+               /*
+                * Timeouts are handled by mmc core, so set a large value to
+                * avoid races.
+                */
+               req->timeout = 600 * HZ;
+               break;
+       }
+
+       mq->cqe_in_flight[issue_type] += 1;
+       get_card = mmc_cqe_tot_in_flight(mq) == 1;
+       retune_ok = mmc_cqe_qcnt(mq) == 1;
+
+       spin_unlock_irq(q->queue_lock);
+
+       if (!(req->rq_flags & RQF_DONTPREP)) {
+               req_to_mmc_queue_req(req)->retries = 0;
+               req->rq_flags |= RQF_DONTPREP;
+       }
+
+       if (get_card)
+               mmc_ctx_get_card(card, &mq->ctx);
+
+       if (host->need_retune && retune_ok && !host->hold_retune)
+               host->retune_now = true;
+       else
+               host->retune_now = false;
+
+       blk_mq_start_request(req);
+
+       issued = mmc_blk_cqe_issue_rq(mq, req);
+
+       switch (issued) {
+       case MMC_REQ_BUSY:
+               ret = BLK_STS_RESOURCE;
+               break;
+       case MMC_REQ_FAILED_TO_START:
+               ret = BLK_STS_IOERR;
+               break;
+       default:
+               ret = BLK_STS_OK;
+               break;
+       }
+
+       if (issued != MMC_REQ_STARTED) {
+               bool put_card = false;
+
+               spin_lock_irq(q->queue_lock);
+               mq->cqe_in_flight[issue_type] -= 1;
+               if (mmc_cqe_tot_in_flight(mq) == 0)
+                       put_card = true;
+               spin_unlock_irq(q->queue_lock);
+               if (put_card)
+                       mmc_ctx_put_card(card, &mq->ctx);
+       }
+
+       return ret;
+}
+
+static const struct blk_mq_ops mmc_mq_cqe_ops = {
+       .queue_rq       = mmc_cqe_queue_rq,
+       .init_request   = mmc_mq_init_request,
+       .exit_request   = mmc_mq_exit_request,
+       .complete       = mmc_blk_cqe_complete_rq,
+       .timeout        = mmc_cqe_timed_out,
+};
+
 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 {
        struct mmc_host *host = card->host;
@@ -251,6 +487,63 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct 
mmc_card *card)
 
        /* Initialize thread_sem even if it is not used */
        sema_init(&mq->thread_sem, 1);
+
+       /* Initialize cqe_recovery_work even if it is not used */
+       INIT_WORK(&mq->cqe_recovery_work, mmc_mq_cqe_recovery_handler);
+}
+
+static int mmc_mq_init_queue(struct mmc_queue *mq, int q_depth,
+                            const struct blk_mq_ops *mq_ops, spinlock_t *lock)
+{
+       int ret;
+
+       memset(&mq->tag_set, 0, sizeof(mq->tag_set));
+       mq->tag_set.ops = mq_ops;
+       mq->tag_set.queue_depth = q_depth;
+       mq->tag_set.numa_node = NUMA_NO_NODE;
+       mq->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE |
+                           BLK_MQ_F_BLOCKING;
+       mq->tag_set.nr_hw_queues = 1;
+       mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
+       mq->tag_set.driver_data = mq;
+
+       ret = blk_mq_alloc_tag_set(&mq->tag_set);
+       if (ret)
+               return ret;
+
+       mq->queue = blk_mq_init_queue(&mq->tag_set);
+       if (IS_ERR(mq->queue)) {
+               ret = PTR_ERR(mq->queue);
+               goto free_tag_set;
+       }
+
+       mq->queue->queue_lock = lock;
+       mq->queue->queuedata = mq;
+
+       return 0;
+
+free_tag_set:
+       blk_mq_free_tag_set(&mq->tag_set);
+
+       return ret;
+}
+
+static int mmc_cqe_init_queue(struct mmc_queue *mq, struct mmc_card *card,
+                             spinlock_t *lock)
+{
+       struct mmc_host *host = card->host;
+       int q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
+       int ret;
+
+       ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_cqe_ops, lock);
+       if (ret)
+               return ret;
+
+       blk_queue_rq_timeout(mq->queue, 60 * HZ);
+
+       mmc_setup_queue(mq, card);
+
+       return 0;
 }
 
 /**
@@ -263,12 +556,16 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct 
mmc_card *card)
  * Initialise a MMC card request queue.
  */
 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
-                  spinlock_t *lock, const char *subname)
+                  spinlock_t *lock, const char *subname, int area_type)
 {
        struct mmc_host *host = card->host;
        int ret = -ENOMEM;
 
        mq->card = card;
+
+       if (host->cqe_enabled && area_type != MMC_BLK_DATA_AREA_RPMB)
+               return mmc_cqe_init_queue(mq, card, lock);
+
        mq->queue = blk_alloc_queue(GFP_KERNEL);
        if (!mq->queue)
                return -ENOMEM;
@@ -304,11 +601,63 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card 
*card,
        return ret;
 }
 
+static void mmc_mq_queue_suspend(struct mmc_queue *mq)
+{
+       blk_mq_quiesce_queue(mq->queue);
+
+       /*
+        * The host remains claimed while there are outstanding requests, so
+        * simply claiming and releasing here ensures there are none.
+        */
+       mmc_claim_host(mq->card->host);
+       mmc_release_host(mq->card->host);
+}
+
+static void mmc_mq_queue_resume(struct mmc_queue *mq)
+{
+       blk_mq_unquiesce_queue(mq->queue);
+}
+
+static void __mmc_queue_suspend(struct mmc_queue *mq)
+{
+       struct request_queue *q = mq->queue;
+       unsigned long flags;
+
+       if (!mq->suspended) {
+               mq->suspended |= true;
+
+               spin_lock_irqsave(q->queue_lock, flags);
+               blk_stop_queue(q);
+               spin_unlock_irqrestore(q->queue_lock, flags);
+
+               down(&mq->thread_sem);
+       }
+}
+
+static void __mmc_queue_resume(struct mmc_queue *mq)
+{
+       struct request_queue *q = mq->queue;
+       unsigned long flags;
+
+       if (mq->suspended) {
+               mq->suspended = false;
+
+               up(&mq->thread_sem);
+
+               spin_lock_irqsave(q->queue_lock, flags);
+               blk_start_queue(q);
+               spin_unlock_irqrestore(q->queue_lock, flags);
+       }
+}
+
 void mmc_cleanup_queue(struct mmc_queue *mq)
 {
        struct request_queue *q = mq->queue;
        unsigned long flags;
 
+       if (q->mq_ops)
+               return;
+
        /* Make sure the queue isn't suspended, as that will deadlock */
        mmc_queue_resume(mq);
 
@@ -336,17 +685,11 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
 void mmc_queue_suspend(struct mmc_queue *mq)
 {
        struct request_queue *q = mq->queue;
-       unsigned long flags;
-
-       if (!mq->suspended) {
-               mq->suspended |= true;
 
-               spin_lock_irqsave(q->queue_lock, flags);
-               blk_stop_queue(q);
-               spin_unlock_irqrestore(q->queue_lock, flags);
-
-               down(&mq->thread_sem);
-       }
+       if (q->mq_ops)
+               mmc_mq_queue_suspend(mq);
+       else
+               __mmc_queue_suspend(mq);
 }
 
 /**
@@ -356,17 +699,11 @@ void mmc_queue_suspend(struct mmc_queue *mq)
 void mmc_queue_resume(struct mmc_queue *mq)
 {
        struct request_queue *q = mq->queue;
-       unsigned long flags;
-
-       if (mq->suspended) {
-               mq->suspended = false;
 
-               up(&mq->thread_sem);
-
-               spin_lock_irqsave(q->queue_lock, flags);
-               blk_start_queue(q);
-               spin_unlock_irqrestore(q->queue_lock, flags);
-       }
+       if (q->mq_ops)
+               mmc_mq_queue_resume(mq);
+       else
+               __mmc_queue_resume(mq);
 }
 
 /*
diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
index 04fc89360a7a..eb474fb7ffb2 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -7,6 +7,20 @@
 #include <linux/mmc/core.h>
 #include <linux/mmc/host.h>
 
+enum mmc_issued {
+       MMC_REQ_STARTED,
+       MMC_REQ_BUSY,
+       MMC_REQ_FAILED_TO_START,
+       MMC_REQ_FINISHED,
+};
+
+enum mmc_issue_type {
+       MMC_ISSUE_SYNC,
+       MMC_ISSUE_DCMD,
+       MMC_ISSUE_ASYNC,
+       MMC_ISSUE_MAX,
+};
+
 static inline struct mmc_queue_req *req_to_mmc_queue_req(struct request *rq)
 {
        return blk_mq_rq_to_pdu(rq);
@@ -57,12 +71,15 @@ struct mmc_queue_req {
        int                     drv_op_result;
        void                    *drv_op_data;
        unsigned int            ioc_count;
+       int                     retries;
 };
 
 struct mmc_queue {
        struct mmc_card         *card;
        struct task_struct      *thread;
        struct semaphore        thread_sem;
+       struct mmc_ctx          ctx;
+       struct blk_mq_tag_set   tag_set;
        bool                    suspended;
        bool                    asleep;
        struct mmc_blk_data     *blkdata;
@@ -74,10 +91,18 @@ struct mmc_queue {
         * associated mmc_queue_req data.
         */
        int                     qcnt;
+       /* Following are defined for a Command Queue Engine */
+       int                     cqe_in_flight[MMC_ISSUE_MAX];
+       unsigned int            cqe_busy;
+       bool                    cqe_recovery_needed;
+       bool                    cqe_in_recovery;
+#define MMC_CQE_DCMD_BUSY      BIT(0)
+#define MMC_CQE_QUEUE_FULL     BIT(1)
+       struct work_struct      cqe_recovery_work;
 };
 
 extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
-                         const char *);
+                         const char *, int);
 extern void mmc_cleanup_queue(struct mmc_queue *);
 extern void mmc_queue_suspend(struct mmc_queue *);
 extern void mmc_queue_resume(struct mmc_queue *);
@@ -89,4 +114,23 @@ extern unsigned int mmc_queue_map_sg(struct mmc_queue *,
 
 extern int mmc_access_rpmb(struct mmc_queue *);
 
+void mmc_cqe_check_busy(struct mmc_queue *mq);
+void mmc_cqe_recovery_notifier(struct mmc_request *mrq);
+
+enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
+                                      struct request *req);
+
+static inline int mmc_cqe_tot_in_flight(struct mmc_queue *mq)
+{
+       return mq->cqe_in_flight[MMC_ISSUE_SYNC] +
+              mq->cqe_in_flight[MMC_ISSUE_DCMD] +
+              mq->cqe_in_flight[MMC_ISSUE_ASYNC];
+}
+
+static inline int mmc_cqe_qcnt(struct mmc_queue *mq)
+{
+       return mq->cqe_in_flight[MMC_ISSUE_DCMD] +
+              mq->cqe_in_flight[MMC_ISSUE_ASYNC];
+}
+
 #endif
-- 
1.9.1

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