[PATCH V12 2/5] mmc: block: Add blk-mq support

From: Adrian Hunter
Date: Tue Oct 24 2017 - 04:47:45 EST

Define and use a blk-mq queue. Discards and flushes are processed
synchronously, but reads and writes asynchronously. In order to support
slow DMA unmapping, DMA unmapping is not done until after the next request
is started. That means the request is not completed until then. If there is
no next request then the completion is done by queued work.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/core/block.c | 655 ++++++++++++++++++++++++++++++++++++++++++++++-
drivers/mmc/core/block.h | 10 +
drivers/mmc/core/queue.c | 302 ++++++++++++++++++++--
drivers/mmc/core/queue.h | 41 +++
include/linux/mmc/host.h | 1 +
5 files changed, 979 insertions(+), 30 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index ea80ff4cd7f9..002446e8dc5d 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1264,7 +1264,10 @@ static void mmc_blk_issue_drv_op(struct mmc_queue *mq, struct request *req)
break;
}
mq_rq->drv_op_result = ret;
- 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);
}

static void mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
@@ -1307,7 +1310,10 @@ 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,
@@ -1377,7 +1383,10 @@ 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)
@@ -1387,7 +1396,10 @@ 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);
}

/*
@@ -1413,15 +1425,18 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
}
}

-#define CMD_ERRORS \
- (R1_OUT_OF_RANGE | /* Command argument out of range */ \
- R1_ADDRESS_ERROR | /* Misaligned address */ \
+#define CMD_ERRORS_EXCL_OOR \
+ (R1_ADDRESS_ERROR | /* Misaligned address */ \
R1_BLOCK_LEN_ERROR | /* Transferred block length incorrect */\
R1_WP_VIOLATION | /* Tried to write to protected block */ \
R1_CARD_ECC_FAILED | /* Card ECC failed */ \
R1_CC_ERROR | /* Card controller error */ \
R1_ERROR) /* General/unknown error */

+#define CMD_ERRORS \
+ (CMD_ERRORS_EXCL_OOR | \
+ R1_OUT_OF_RANGE) /* Command argument out of range */ \
+
static void mmc_blk_eval_resp_error(struct mmc_blk_request *brq)
{
u32 val;
@@ -1766,6 +1781,632 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
mqrq->areq.err_check = mmc_blk_err_check;
}

+#define MMC_MAX_RETRIES 5
+#define MMC_DATA_RETRIES 2
+#define MMC_NO_RETRIES (MMC_MAX_RETRIES + 1)
+
+/* Single sector read during recovery */
+static void mmc_blk_ss_read(struct mmc_queue *mq, struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ blk_status_t status;
+
+ while (1) {
+ mmc_blk_rw_rq_prep(mqrq, mq->card, 1, mq);
+
+ mmc_wait_for_req(mq->card->host, &mqrq->brq.mrq);
+
+ /*
+ * Not expecting command errors, so just give up in that case.
+ * If there are retries remaining, the request will get
+ * requeued.
+ */
+ if (mqrq->brq.cmd.error)
+ return;
+
+ if (blk_rq_bytes(req) <= 512)
+ break;
+
+ status = mqrq->brq.data.error ? BLK_STS_IOERR : BLK_STS_OK;
+
+ blk_update_request(req, status, 512);
+ }
+
+ mqrq->retries = MMC_NO_RETRIES;
+}
+
+static inline bool mmc_blk_oor_valid(struct mmc_blk_request *brq)
+{
+ return !!brq->mrq.sbc;
+}
+
+static inline u32 mmc_blk_stop_err_bits(struct mmc_blk_request *brq)
+{
+ return mmc_blk_oor_valid(brq) ? CMD_ERRORS : CMD_ERRORS_EXCL_OOR;
+}
+
+static inline bool mmc_blk_in_tran_state(u32 status)
+{
+ /*
+ * Some cards mishandle the status bits, so make sure to check both the
+ * busy indication and the card state.
+ */
+ return status & R1_READY_FOR_DATA &&
+ (R1_CURRENT_STATE(status) == R1_STATE_TRAN);
+}
+
+/*
+ * Check for errors the host controller driver might not have seen such as
+ * response mode errors or invalid card state.
+ */
+static bool mmc_blk_status_error(struct request *req, u32 status)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_blk_request *brq = &mqrq->brq;
+ u32 stop_err_bits = mmc_blk_stop_err_bits(brq);
+
+ return brq->cmd.resp[0] & CMD_ERRORS ||
+ brq->stop.resp[0] & stop_err_bits ||
+ status & stop_err_bits ||
+ (rq_data_dir(req) == WRITE && !mmc_blk_in_tran_state(status));
+}
+
+static inline bool mmc_blk_cmd_started(struct mmc_blk_request *brq)
+{
+ return !brq->sbc.error && !brq->cmd.error &&
+ !(brq->cmd.resp[0] & CMD_ERRORS);
+}
+
+static unsigned int mmc_blk_clock_khz(struct mmc_host *host)
+{
+ if (host->actual_clock)
+ return host->actual_clock / 1000;
+
+ /* Clock may be subject to a divisor, fudge it by a factor of 2. */
+ if (host->ios.clock)
+ return host->ios.clock / 2000;
+
+ /* How can there be no clock */
+ WARN_ON_ONCE(1);
+ return 100; /* 100 kHz is minimum possible value */
+}
+
+static unsigned long mmc_blk_data_timeout_jiffies(struct mmc_host *host,
+ struct mmc_data *data)
+{
+ unsigned int ms = DIV_ROUND_UP(data->timeout_ns, 1000000);
+ unsigned int khz;
+
+ if (data->timeout_clks) {
+ khz = mmc_blk_clock_khz(host);
+ ms += DIV_ROUND_UP(data->timeout_clks, khz);
+ }
+
+ return msecs_to_jiffies(ms);
+}
+
+static int mmc_blk_card_stuck(struct mmc_card *card, struct request *req,
+ u32 *resp_errs)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_data *data = &mqrq->brq.data;
+ unsigned long timeout;
+ u32 status;
+ int err;
+
+ timeout = jiffies + mmc_blk_data_timeout_jiffies(card->host, data);
+
+ while (1) {
+ bool done = time_after(jiffies, timeout);
+
+ err = __mmc_send_status(card, &status, 5);
+ if (err) {
+ pr_err("%s: error %d requesting status\n",
+ req->rq_disk->disk_name, err);
+ break;
+ }
+
+ /* Accumulate any response error bits seen */
+ if (resp_errs)
+ *resp_errs |= status;
+
+ if (mmc_blk_in_tran_state(status))
+ break;
+
+ /* Timeout if the device never becomes ready */
+ if (done) {
+ pr_err("%s: Card stuck in wrong state! %s %s\n",
+ mmc_hostname(card->host),
+ req->rq_disk->disk_name, __func__);
+ err = -ETIMEDOUT;
+ break;
+ }
+ }
+
+ return err;
+}
+
+static int mmc_blk_send_stop(struct mmc_card *card)
+{
+ struct mmc_command cmd = {
+ .opcode = MMC_STOP_TRANSMISSION,
+ .flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC,
+ };
+
+ return mmc_wait_for_cmd(card->host, &cmd, 5);
+}
+
+static int mmc_blk_fix_state(struct mmc_card *card, struct request *req)
+{
+ int err;
+
+ mmc_retune_hold_now(card->host);
+
+ mmc_blk_send_stop(card);
+
+ err = mmc_blk_card_stuck(card, req, NULL);
+
+ mmc_retune_release(card->host);
+
+ return err;
+}
+
+static void mmc_blk_rw_recovery(struct mmc_queue *mq, struct request *req)
+{
+ int type = rq_data_dir(req) == READ ? MMC_BLK_READ : MMC_BLK_WRITE;
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_blk_request *brq = &mqrq->brq;
+ struct mmc_blk_data *md = mq->blkdata;
+ struct mmc_card *card = mq->card;
+ u32 status;
+ u32 blocks;
+ int err;
+
+ /*
+ * Status error bits might get lost during re-tuning so don't allow
+ * re-tuning yet.
+ */
+ mmc_retune_hold_now(card->host);
+
+ /*
+ * Some errors the host driver might not have seen. Set the number of
+ * bytes transferred to zero in that case.
+ */
+ err = __mmc_send_status(card, &status, 0);
+ if (err || mmc_blk_status_error(req, status))
+ brq->data.bytes_xfered = 0;
+
+ mmc_retune_release(card->host);
+
+ /*
+ * Try again to get the status. This also provides an opportunity for
+ * re-tuning.
+ */
+ if (err)
+ err = __mmc_send_status(card, &status, 0);
+
+ /*
+ * Nothing more to do after the number of bytes transferred has been
+ * updated and there is no card.
+ */
+ if (err && mmc_detect_card_removed(card->host))
+ return;
+
+ /* Try to get back to "tran" state */
+ if (err || !mmc_blk_in_tran_state(status))
+ err = mmc_blk_fix_state(mq->card, req);
+
+ /*
+ * Special case for SD cards where the card might record the number of
+ * blocks written.
+ */
+ if (!err && mmc_blk_cmd_started(brq) && mmc_card_sd(card) &&
+ rq_data_dir(req) == WRITE && !mmc_sd_num_wr_blocks(card, &blocks))
+ brq->data.bytes_xfered = blocks << 9;
+
+ /* Reset if the card is in a bad state */
+ if (err && mmc_blk_reset(md, card->host, type)) {
+ pr_err("%s: recovery failed!\n", req->rq_disk->disk_name);
+ mqrq->retries = MMC_NO_RETRIES;
+ return;
+ }
+
+ /*
+ * If anything was done, just return and if there is anything remaining
+ * on the request it will get requeued.
+ */
+ if (brq->data.bytes_xfered)
+ return;
+
+ /* Reset before last retry */
+ if (mqrq->retries + 1 == MMC_MAX_RETRIES)
+ mmc_blk_reset(md, card->host, type);
+
+ /* Command errors fail fast, so use all MMC_MAX_RETRIES */
+ if (brq->sbc.error || brq->cmd.error)
+ return;
+
+ /* Reduce the remaining retries for data errors */
+ if (mqrq->retries < MMC_MAX_RETRIES - MMC_DATA_RETRIES) {
+ mqrq->retries = MMC_MAX_RETRIES - MMC_DATA_RETRIES;
+ return;
+ }
+
+ /* FIXME: Missing single sector read for large sector size */
+ if (rq_data_dir(req) == READ && !mmc_large_sector(card)) {
+ /* Read one sector at a time */
+ mmc_blk_ss_read(mq, req);
+ return;
+ }
+}
+
+static inline bool mmc_blk_rq_error(struct mmc_blk_request *brq)
+{
+ mmc_blk_eval_resp_error(brq);
+
+ return brq->sbc.error || brq->cmd.error || brq->stop.error ||
+ brq->data.error || brq->cmd.resp[0] & CMD_ERRORS;
+}
+
+static int mmc_blk_card_busy(struct mmc_card *card, struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ u32 status = 0;
+ int err;
+
+ if (mmc_host_is_spi(card->host) || rq_data_dir(req) == READ)
+ return 0;
+
+ mmc_retune_hold_now(card->host);
+
+ err = mmc_blk_card_stuck(card, req, &status);
+
+ mmc_retune_release(card->host);
+
+ /*
+ * Do not assume data transferred correctly if there are any error bits
+ * set.
+ */
+ if (!err && status & mmc_blk_stop_err_bits(&mqrq->brq)) {
+ mqrq->brq.data.bytes_xfered = 0;
+ err = -EIO;
+ }
+
+ /* Copy the exception bit so it will be seen later on */
+ if (mmc_card_mmc(card) && status & R1_EXCEPTION_EVENT)
+ mqrq->brq.cmd.resp[0] |= R1_EXCEPTION_EVENT;
+
+ return err;
+}
+
+static inline void mmc_blk_rw_reset_success(struct mmc_queue *mq,
+ struct request *req)
+{
+ int type = rq_data_dir(req) == READ ? MMC_BLK_READ : MMC_BLK_WRITE;
+
+ mmc_blk_reset_success(mq->blkdata, type);
+}
+
+static void mmc_blk_mq_complete_rq(struct mmc_queue *mq, struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ unsigned int nr_bytes = mqrq->brq.data.bytes_xfered;
+
+ if (nr_bytes) {
+ if (blk_update_request(req, BLK_STS_OK, nr_bytes))
+ blk_mq_requeue_request(req, true);
+ else
+ __blk_mq_end_request(req, BLK_STS_OK);
+ } else if (mqrq->retries++ < MMC_MAX_RETRIES) {
+ blk_mq_requeue_request(req, true);
+ } else {
+ if (mmc_card_removed(mq->card))
+ req->rq_flags |= RQF_QUIET;
+ blk_mq_end_request(req, BLK_STS_IOERR);
+ }
+}
+
+static bool mmc_blk_urgent_bkops_needed(struct mmc_queue *mq,
+ struct mmc_queue_req *mqrq)
+{
+ return mmc_card_mmc(mq->card) &&
+ (mqrq->brq.cmd.resp[0] & R1_EXCEPTION_EVENT ||
+ mqrq->brq.stop.resp[0] & R1_EXCEPTION_EVENT);
+}
+
+static void mmc_blk_urgent_bkops(struct mmc_queue *mq,
+ struct mmc_queue_req *mqrq)
+{
+ if (mmc_blk_urgent_bkops_needed(mq, mqrq))
+ mmc_start_bkops(mq->card, true);
+}
+
+void mmc_blk_mq_complete(struct request *req)
+{
+ struct mmc_queue *mq = req->q->queuedata;
+
+ mmc_blk_mq_complete_rq(mq, req);
+}
+
+static void mmc_blk_mq_poll_completion(struct mmc_queue *mq,
+ struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_host *host = mq->card->host;
+ bool failed;
+
+ failed = mmc_blk_rq_error(&mqrq->brq) ||
+ mmc_blk_card_busy(mq->card, req);
+
+ if (!mmc_queue_direct_complete(host))
+ mmc_retune_release(host);
+
+ if (failed)
+ mmc_blk_rw_recovery(mq, req);
+ else
+ mmc_blk_rw_reset_success(mq, req);
+
+ mmc_blk_urgent_bkops(mq, mqrq);
+}
+
+static void mmc_blk_mq_acct_req_done(struct mmc_queue *mq, struct request *req)
+{
+ struct request_queue *q = req->q;
+ unsigned long flags;
+ bool put_card;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+
+ mq->in_flight[mmc_issue_type(mq, req)] -= 1;
+
+ put_card = mmc_tot_in_flight(mq) == 0;
+
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ if (put_card)
+ mmc_put_card(mq->card, &mq->ctx);
+}
+
+static void mmc_blk_mq_post_req(struct mmc_queue *mq, struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_request *mrq = &mqrq->brq.mrq;
+ struct mmc_host *host = mq->card->host;
+
+ if (host->ops->post_req)
+ host->ops->post_req(host, mrq, 0);
+
+ /*
+ * Block layer timeouts race with completions which means the normal
+ * completion path cannot be used during recovery.
+ */
+ if (mq->in_recovery)
+ mmc_blk_mq_complete_rq(mq, req);
+ else
+ blk_mq_complete_request(req);
+
+ mmc_blk_mq_acct_req_done(mq, req);
+}
+
+void mmc_blk_mq_recovery(struct mmc_queue *mq)
+{
+ struct request *req = mq->recovery_req;
+
+ mq->recovery_req = NULL;
+ mq->rw_wait = false;
+
+ mmc_blk_mq_poll_completion(mq, req);
+
+ mmc_blk_mq_post_req(mq, req);
+}
+
+static void mmc_blk_mq_complete_prev_req(struct mmc_queue *mq,
+ struct request **prev_req)
+{
+ if (mmc_queue_direct_complete(mq->card->host))
+ return;
+
+ mutex_lock(&mq->complete_lock);
+
+ if (!mq->complete_req)
+ goto out_unlock;
+
+ mmc_blk_mq_poll_completion(mq, mq->complete_req);
+
+ if (prev_req)
+ *prev_req = mq->complete_req;
+ else
+ mmc_blk_mq_post_req(mq, mq->complete_req);
+
+ mq->complete_req = NULL;
+
+out_unlock:
+ mutex_unlock(&mq->complete_lock);
+}
+
+void mmc_blk_mq_complete_work(struct work_struct *work)
+{
+ struct mmc_queue *mq = container_of(work, struct mmc_queue,
+ complete_work);
+
+ mmc_blk_mq_complete_prev_req(mq, NULL);
+}
+
+static void mmc_blk_mq_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;
+ struct mmc_host *host = mq->card->host;
+ unsigned long flags;
+
+ if (mmc_blk_rq_error(&mqrq->brq) ||
+ mmc_blk_urgent_bkops_needed(mq, mqrq)) {
+ spin_lock_irqsave(q->queue_lock, flags);
+ mq->recovery_needed = true;
+ mq->recovery_req = req;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ wake_up(&mq->wait);
+ schedule_work(&mq->recovery_work);
+ return;
+ }
+
+ if (!mmc_queue_direct_complete(host)) {
+ bool waiting;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ mq->complete_req = req;
+ mq->rw_wait = false;
+ waiting = mq->waiting;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ if (waiting)
+ wake_up(&mq->wait);
+ else
+ kblockd_schedule_work(&mq->complete_work);
+
+ return;
+ }
+
+ mmc_blk_rw_reset_success(mq, req);
+
+ mq->rw_wait = false;
+ wake_up(&mq->wait);
+
+ mmc_blk_mq_post_req(mq, req);
+}
+
+static bool mmc_blk_rw_wait_cond(struct mmc_queue *mq, int *err)
+{
+ struct request_queue *q = mq->queue;
+ unsigned long flags;
+ bool done;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ if (mq->recovery_needed) {
+ *err = -EBUSY;
+ done = true;
+ } else {
+ done = !mq->rw_wait;
+ }
+ mq->waiting = !done;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ return done;
+}
+
+static int mmc_blk_rw_wait(struct mmc_queue *mq, struct request **prev_req)
+{
+ int err = 0;
+
+ wait_event(mq->wait, mmc_blk_rw_wait_cond(mq, &err));
+
+ mmc_blk_mq_complete_prev_req(mq, prev_req);
+
+ return err;
+}
+
+static int mmc_blk_mq_issue_rw_rq(struct mmc_queue *mq,
+ struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_host *host = mq->card->host;
+ struct request *prev_req = NULL;
+ int err = 0;
+
+ mmc_blk_rw_rq_prep(mqrq, mq->card, 0, mq);
+
+ mqrq->brq.mrq.done = mmc_blk_mq_req_done;
+
+ if (host->ops->pre_req)
+ host->ops->pre_req(host, &mqrq->brq.mrq);
+
+ err = mmc_blk_rw_wait(mq, &prev_req);
+ if (err)
+ goto out_post_req;
+
+ mq->rw_wait = true;
+
+ err = mmc_start_request(host, &mqrq->brq.mrq);
+
+ if (prev_req)
+ mmc_blk_mq_post_req(mq, prev_req);
+
+ if (err)
+ mq->rw_wait = false;
+
+ /* Release re-tuning here where there is no synchronization required */
+ if (mmc_queue_direct_complete(host))
+ mmc_retune_release(host);
+
+out_post_req:
+ if (err && host->ops->post_req)
+ host->ops->post_req(host, &mqrq->brq.mrq, err);
+
+ return err;
+}
+
+static int mmc_blk_wait_for_idle(struct mmc_queue *mq, struct mmc_host *host)
+{
+ return mmc_blk_rw_wait(mq, NULL);
+}
+
+enum mmc_issued mmc_blk_mq_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_issue_type(mq, req)) {
+ case MMC_ISSUE_SYNC:
+ ret = mmc_blk_wait_for_idle(mq, 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_ASYNC:
+ switch (req_op(req)) {
+ case REQ_OP_READ:
+ case REQ_OP_WRITE:
+ ret = mmc_blk_mq_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 bool mmc_blk_rw_cmd_err(struct mmc_blk_data *md, struct mmc_card *card,
struct mmc_blk_request *brq, struct request *req,
bool old_req_pending)
diff --git a/drivers/mmc/core/block.h b/drivers/mmc/core/block.h
index 860ca7c8df86..b145ed81402b 100644
--- a/drivers/mmc/core/block.h
+++ b/drivers/mmc/core/block.h
@@ -6,4 +6,14 @@

void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req);

+enum mmc_issued;
+
+enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req);
+void mmc_blk_mq_complete(struct request *req);
+void mmc_blk_mq_recovery(struct mmc_queue *mq);
+
+struct work_struct;
+
+void mmc_blk_mq_complete_work(struct work_struct *work);
+
#endif
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 4f33d277b125..d3b5881615f5 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"

/*
* Prepare a MMC request. This just filters out odd stuff.
@@ -34,10 +35,48 @@ 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;
}

+enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req)
+{
+ if (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE)
+ return MMC_ISSUE_ASYNC;
+
+ return MMC_ISSUE_SYNC;
+}
+
+static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req,
+ bool reserved)
+{
+ return BLK_EH_RESET_TIMER;
+}
+
+static void mmc_mq_recovery_handler(struct work_struct *work)
+{
+ struct mmc_queue *mq = container_of(work, struct mmc_queue,
+ recovery_work);
+ struct request_queue *q = mq->queue;
+
+ mmc_get_card(mq->card, &mq->ctx);
+
+ mq->in_recovery = true;
+
+ mmc_blk_mq_recovery(mq);
+
+ mq->in_recovery = false;
+
+ spin_lock_irq(q->queue_lock);
+ mq->recovery_needed = false;
+ spin_unlock_irq(q->queue_lock);
+
+ mmc_put_card(mq->card, &mq->ctx);
+
+ blk_mq_run_hw_queues(q, true);
+}
+
static int mmc_queue_thread(void *d)
{
struct mmc_queue *mq = d;
@@ -154,11 +193,10 @@ static void mmc_queue_setup_discard(struct request_queue *q,
* @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;

@@ -169,6 +207,12 @@ 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);
@@ -177,6 +221,110 @@ 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_mq_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;
+ enum mmc_issue_type issue_type;
+ enum mmc_issued issued;
+ bool get_card;
+ int ret;
+
+ if (mmc_card_removed(mq->card)) {
+ req->rq_flags |= RQF_QUIET;
+ return BLK_STS_IOERR;
+ }
+
+ issue_type = mmc_issue_type(mq, req);
+
+ spin_lock_irq(q->queue_lock);
+
+ if (mq->recovery_needed) {
+ spin_unlock_irq(q->queue_lock);
+ return BLK_STS_RESOURCE;
+ }
+
+ switch (issue_type) {
+ 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->in_flight[issue_type] += 1;
+ get_card = mmc_tot_in_flight(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_get_card(card, &mq->ctx);
+
+ blk_mq_start_request(req);
+
+ issued = mmc_blk_mq_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->in_flight[issue_type] -= 1;
+ if (mmc_tot_in_flight(mq) == 0)
+ put_card = true;
+ spin_unlock_irq(q->queue_lock);
+ if (put_card)
+ mmc_put_card(card, &mq->ctx);
+ }
+
+ return ret;
+}
+
+static const struct blk_mq_ops mmc_mq_ops = {
+ .queue_rq = mmc_mq_queue_rq,
+ .init_request = mmc_mq_init_request,
+ .exit_request = mmc_mq_exit_request,
+ .complete = mmc_blk_mq_complete,
+ .timeout = mmc_mq_timed_out,
+};
+
static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
{
struct mmc_host *host = card->host;
@@ -198,6 +346,70 @@ 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);
+
+ INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
+ INIT_WORK(&mq->complete_work, mmc_blk_mq_complete_work);
+
+ mutex_init(&mq->complete_lock);
+
+ init_waitqueue_head(&mq->wait);
+}
+
+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;
+}
+
+#define MMC_QUEUE_DEPTH 64
+
+static int mmc_mq_init(struct mmc_queue *mq, struct mmc_card *card,
+ spinlock_t *lock)
+{
+ int q_depth;
+ int ret;
+
+ q_depth = MMC_QUEUE_DEPTH;
+
+ ret = mmc_mq_init_queue(mq, q_depth, &mmc_mq_ops, lock);
+ if (ret)
+ return ret;
+
+ blk_queue_rq_timeout(mq->queue, 60 * HZ);
+
+ mmc_setup_queue(mq, card);
+
+ return 0;
}

/**
@@ -216,6 +428,10 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
int ret = -ENOMEM;

mq->card = card;
+
+ if (mmc_host_use_blk_mq(host))
+ return mmc_mq_init(mq, card, lock);
+
mq->queue = blk_alloc_queue(GFP_KERNEL);
if (!mq->queue)
return -ENOMEM;
@@ -251,11 +467,63 @@ 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);

@@ -283,17 +551,11 @@ 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);
}

/**
@@ -303,17 +565,11 @@ 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 68f68ecd94ea..00b4ce2ce83c 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -7,6 +7,19 @@
#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_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);
@@ -56,12 +69,15 @@ 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;
@@ -73,6 +89,18 @@ struct mmc_queue {
* associated mmc_queue_req data.
*/
int qcnt;
+
+ int in_flight[MMC_ISSUE_MAX];
+ bool recovery_needed;
+ bool in_recovery;
+ bool rw_wait;
+ bool waiting;
+ struct work_struct recovery_work;
+ wait_queue_head_t wait;
+ struct request *recovery_req;
+ struct request *complete_req;
+ struct mutex complete_lock;
+ struct work_struct complete_work;
};

extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
@@ -83,4 +111,17 @@ extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
extern unsigned int mmc_queue_map_sg(struct mmc_queue *,
struct mmc_queue_req *);

+enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req);
+
+static inline int mmc_tot_in_flight(struct mmc_queue *mq)
+{
+ return mq->in_flight[MMC_ISSUE_SYNC] +
+ mq->in_flight[MMC_ISSUE_ASYNC];
+}
+
+static inline bool mmc_queue_direct_complete(struct mmc_host *host)
+{
+ return host->caps & MMC_CAP_DIRECT_COMPLETE;
+}
+
#endif
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ce2075d6f429..4b68a95a8818 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -324,6 +324,7 @@ struct mmc_host {
#define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
#define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
#define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */
+#define MMC_CAP_DIRECT_COMPLETE (1 << 27) /* RW reqs can be completed within mmc_request_done() */
#define MMC_CAP_CD_WAKE (1 << 28) /* Enable card detect wake */
#define MMC_CAP_CMD_DURING_TFR (1 << 29) /* Commands during data transfer */
#define MMC_CAP_CMD23 (1 << 30) /* CMD23 supported. */
--
1.9.1