@@ -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);
}
/*
@@ -1372,15 +1382,18 @@ 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;
@@ -1659,6 +1672,138 @@ 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
+
+static void mmc_blk_cqe_complete_rq(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 request_queue *q = req->q;
+ 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->in_flight[mmc_issue_type(mq, req)] -= 1;
+
+ put_card = mmc_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;
+
+ pr_debug("%s: CQE recovery start\n", mmc_hostname(host));
+
+ 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);
+
+ pr_debug("%s: CQE recovery done\n", mmc_hostname(host));
+}
+
+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->in_recovery)
+ mmc_blk_cqe_complete_rq(mq, 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);
+}
+
static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
struct mmc_card *card,
int disable_multi,
@@ -1727,6 +1872,581 @@ 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);
+}
+
+static int mmc_blk_card_busy_check(struct mmc_queue *mq, struct request *req)
+{
+ if (mmc_queue_rw_async(mq->card->host))
+ return 0;
+
+ return mmc_blk_card_busy(mq->card, req);
+}
+
+void mmc_blk_mq_complete(struct request *req)
+{
+ struct mmc_queue *mq = req->q->queuedata;
+
+ if (mq->use_cqe)
+ mmc_blk_cqe_complete_rq(mq, req);
+ else
+ mmc_blk_mq_complete_rq(mq, req);
+}
+
+static void mmc_blk_finish_rw_rq_blocking(struct mmc_queue *mq,
+ struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+
+ if (mmc_blk_rq_error(&mqrq->brq) || mmc_blk_card_busy_check(mq, req))
+ mmc_blk_rw_recovery(mq, req);
+ else
+ mmc_blk_rw_reset_success(mq, req);
+
+ mmc_blk_urgent_bkops(mq, mqrq);
+
+ mq->rw_wait = false;
+
+ /*
+ * 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);
+}
+
+void mmc_blk_mq_recovery(struct mmc_queue *mq)
+{
+ struct request *req = mq->recovery_req;
+
+ mq->recovery_req = NULL;
+
+ mmc_blk_finish_rw_rq_blocking(mq, req);
+}
+
+static void mmc_blk_issue_rw_rq_blocking(struct mmc_queue *mq,
+ struct request *req)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+
+ mmc_blk_rw_rq_prep(mqrq, mq->card, 0, mq);
+
+ mmc_wait_for_req(mq->card->host, &mqrq->brq.mrq);
+
+ mmc_blk_finish_rw_rq_blocking(mq, req);
+}
+
+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;
+ bool put_card;
+
+ if (mmc_blk_rq_error(&mqrq->brq) ||
+ mmc_blk_urgent_bkops_needed(mq, mqrq)) {
+ mq->recovery_needed = true;
+ mq->recovery_req = req;
+ wake_up(&mq->wait);
+ schedule_work(&mq->recovery_work);
+ return;
+ }
+
+ mmc_blk_rw_reset_success(mq, req);
+
+ if (host->ops->post_req)
+ host->ops->post_req(host, mrq, 0);
+
+ mq->rw_wait = false;
+ wake_up(&mq->wait);
+
+ blk_mq_complete_request(req);
+
+ 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_ctx_put_card(mq->card, &mq->ctx);
+}
+
+static bool mmc_blk_rw_wait_cond(struct mmc_queue *mq, int *err)
+{
+ if (mq->recovery_needed) {
+ *err = -EBUSY;
+ return true;
+ }
+
+ return !mq->rw_wait;
+}
+
+static int mmc_blk_rw_wait(struct mmc_queue *mq)
+{
+ int err = 0;
+
+ wait_event(mq->wait, mmc_blk_rw_wait_cond(mq, &err));
+
+ 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;
+ 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);
+ if (err)
+ goto out_post_req;
+
+ mq->rw_wait = true;
+
+ err = mmc_start_request(host, &mqrq->brq.mrq);
+
+ if (err)
+ mq->rw_wait = false;
+
+ /* Release re-tuning here where there is no synchronization required */
+ 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)
+{
+ if (mq->use_cqe)
+ return host->cqe_ops->cqe_wait_for_idle(host);
+
+ if (mmc_queue_rw_async(host))
+ return mmc_blk_rw_wait(mq);
+
+ return 0;
+}
+
+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;
+ case REQ_OP_READ:
+ case REQ_OP_WRITE:
+ mmc_blk_issue_rw_rq_blocking(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:
+ if (mq->use_cqe)
+ ret = mmc_blk_cqe_issue_rw_rq(mq, req);
+ else
+ 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)
@@ -2094,7 +2814,7 @@ 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;
@@ -6,4 +6,12 @@
void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req);
+enum mmc_issued;
+
+void mmc_blk_cqe_recovery(struct mmc_queue *mq);
+
+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);
+
#endif
@@ -22,6 +22,7 @@
#include "block.h"
#include "core.h"
#include "card.h"
+#include "host.h"
#define MMC_QUEUE_BOUNCESZ 65536
@@ -36,10 +37,153 @@ 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->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;
+ }
+}
+
+enum mmc_issue_type mmc_issue_type(struct mmc_queue *mq, struct request *req)
+{
+ struct mmc_host *host = mq->card->host;
+
+ if (mq->use_cqe)
+ return mmc_cqe_issue_type(host, req);
+
+ if (mmc_queue_rw_async(host) &&
+ (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_WRITE))
+ return MMC_ISSUE_ASYNC;
+
+ return MMC_ISSUE_SYNC;
+}
+
+static void __mmc_cqe_recovery_notifier(struct mmc_queue *mq)
+{
+ if (!mq->recovery_needed) {
+ mq->recovery_needed = true;
+ schedule_work(&mq->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_issue_type(mq, 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_mq_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->recovery_needed || !mq->use_cqe)
+ 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_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_ctx_get_card(mq->card, &mq->ctx);
+
+ mq->in_recovery = true;
+
+ if (mq->use_cqe)
+ mmc_blk_cqe_recovery(mq);
+ else
+ 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_ctx_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;
@@ -176,11 +320,10 @@ 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 +351,12 @@ 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 +372,125 @@ 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;
+ struct mmc_host *host = card->host;
+ enum mmc_issue_type issue_type;
+ enum mmc_issued issued;
+ bool get_card, cqe_retune_ok;
+ int ret;
+
+ if (mmc_card_removed(mq->card) ||
+ (mmc_access_rpmb(mq) && !blk_rq_is_private(req))) {
+ 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_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->in_flight[issue_type] += 1;
+ get_card = mmc_tot_in_flight(mq) == 1;
+ cqe_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 (mq->use_cqe) {
+ host->retune_now = host->need_retune && cqe_retune_ok &&
+ !host->hold_retune;
+ }
+
+ 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_ctx_put_card(card, &mq->ctx);
+ }
+
+ return ret;
+}
+
+static const struct blk_mq_ops mmc_mq_cqe_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;
@@ -250,6 +518,72 @@ 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 recovery_work even if it is not used */
+ INIT_WORK(&mq->recovery_work, mmc_mq_recovery_handler);
+
+ 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)
+{
+ struct mmc_host *host = card->host;
+ int q_depth;
+ int ret;
+
+ if (mq->use_cqe)
+ q_depth = min_t(int, card->ext_csd.cmdq_depth, host->cqe_qdepth);
+ else
+ q_depth = MMC_QUEUE_DEPTH;
+
+ 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;
}
/**
@@ -262,7 +596,7 @@ 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;
@@ -274,6 +608,12 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
card->bouncesz = mmc_queue_calc_bouncesz(host);
mq->card = card;
+
+ mq->use_cqe = host->cqe_enabled && area_type != MMC_BLK_DATA_AREA_RPMB;
+
+ if (mq->use_cqe || 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;
@@ -309,11 +649,63 @@ 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);
@@ -341,17 +733,11 @@ 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);
}
/**
@@ -361,17 +747,11 @@ 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);
}
/*
@@ -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 +91,22 @@ struct mmc_queue {
* associated mmc_queue_req data.
*/
int qcnt;
+
+ int in_flight[MMC_ISSUE_MAX];
+ unsigned int cqe_busy;
+#define MMC_CQE_DCMD_BUSY BIT(0)
+#define MMC_CQE_QUEUE_FULL BIT(1)
+ bool use_cqe;
+ bool recovery_needed;
+ bool in_recovery;
+ bool rw_wait;
+ struct work_struct recovery_work;
+ wait_queue_head_t wait;
+ struct request *recovery_req;
};
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 +118,27 @@ 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_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_DCMD] +
+ mq->in_flight[MMC_ISSUE_ASYNC];
+}
+
+static inline int mmc_cqe_qcnt(struct mmc_queue *mq)
+{
+ return mq->in_flight[MMC_ISSUE_DCMD] +
+ mq->in_flight[MMC_ISSUE_ASYNC];
+}
+
+static inline bool mmc_queue_rw_async(struct mmc_host *host)
+{
+ return host->caps & MMC_CAP_WAIT_WHILE_BUSY;
+}
+
#endif
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. For host controllers without CQE support, blk-mq support is extended to synchronous reads/writes or, if the host supports CAP_WAIT_WHILE_BUSY, asynchonous reads/writes. The advantage of asynchronous reads/writes is that it allows the preparation of the next request while the current request is in progress. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- drivers/mmc/core/block.c | 734 ++++++++++++++++++++++++++++++++++++++++++++++- drivers/mmc/core/block.h | 8 + drivers/mmc/core/queue.c | 428 +++++++++++++++++++++++++-- drivers/mmc/core/queue.h | 54 +++- 4 files changed, 1192 insertions(+), 32 deletions(-)