[v5] mmc: fix async request mechanism for sequential read scenarios

Message ID	1356513966-24945-1-git-send-email-kdorfman@codeaurora.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-mmc-owner@vger.kernel.org> From: Konstantin Dorfman <kdorfman@codeaurora.org> To: cjb@laptop.org Cc: linux-mmc@vger.kernel.org, per.lkml@gmail.com, tgih.jun@samsung.com, Konstantin Dorfman <kdorfman@codeaurora.org> Subject: [PATCH v5] mmc: fix async request mechanism for sequential read scenarios Date: Wed, 26 Dec 2012 11:26:06 +0200 Message-Id: <1356513966-24945-1-git-send-email-kdorfman@codeaurora.org> In-Reply-To: <n> References: <n> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk

I checked the changes. Thanks for your work. Reviewed-by: Seungwon Jeon <tgih.jun@samsung.com> On Wednesday, December 26, 2012, Konstantin Dorfman wrote: > When current request is running on the bus and if next request fetched > by mmcqd is NULL, mmc context (mmcqd thread) gets blocked until the > current request completes. This means that if new request comes in while > the mmcqd thread is blocked, this new request can not be prepared in > parallel to current ongoing request. This may result in delaying the new > request execution and increase it's latency. > > This change allows to wake up the MMC thread on new request arrival. > Now once the MMC thread is woken up, a new request can be fetched and > prepared in parallel to the current running request which means this new > request can be started immediately after the current running request > completes. > > With this change read throughput is improved by 16%. > > Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org> > --- > v5: - Removed BUG() and BUG_ON() with proper error handling > - Turn on of is_waiting_last_req flag moved from queue.c into > block.c (mmc_blk_issue_req()) > - mmc_init_context_info() called from mmc_add_card(). It is > common point for MMC, SD, SDIO. > > v4: keeps new synchronization mechanism within mmc/core > layer, so mmc/core external API's are not changed. > - context_info moved into mmc_host struct > - context_info initialized in mmc_attach_mmc() > > v3: > - new MMC_QUEUE_NEW_REQUEST flag to mark new request case > - lock added to update is_new_req flag > - condition for sending new req notification changed > - Moved start waiting for new req notification > after fetching NULL > v2: > - Removed synchronization flags > - removed lock from done() > - flags names changed > v1: > - Initial submit > > diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c > index 21056b9..f79b468 100644 > --- a/drivers/mmc/card/block.c > +++ b/drivers/mmc/card/block.c > @@ -113,17 +113,6 @@ struct mmc_blk_data { > > static DEFINE_MUTEX(open_lock); > > -enum mmc_blk_status { > - MMC_BLK_SUCCESS = 0, > - MMC_BLK_PARTIAL, > - MMC_BLK_CMD_ERR, > - MMC_BLK_RETRY, > - MMC_BLK_ABORT, > - MMC_BLK_DATA_ERR, > - MMC_BLK_ECC_ERR, > - MMC_BLK_NOMEDIUM, > -}; > - > module_param(perdev_minors, int, 0444); > MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device"); > > @@ -1364,8 +1353,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc) > } else > areq = NULL; > areq = mmc_start_req(card->host, areq, (int *) &status); > - if (!areq) > + if (!areq) { > + if (status == MMC_BLK_NEW_REQUEST) > + mq->flags |= MMC_QUEUE_NEW_REQUEST; > return 0; > + } > > mq_rq = container_of(areq, struct mmc_queue_req, mmc_active); > brq = &mq_rq->brq; > @@ -1438,6 +1430,10 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc) > break; > case MMC_BLK_NOMEDIUM: > goto cmd_abort; > + default: > + pr_err("%s: Unhandled return value (%d)", > + req->rq_disk->disk_name, status); > + goto cmd_abort; > } > > if (ret) { > @@ -1472,6 +1468,8 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) > int ret; > struct mmc_blk_data *md = mq->data; > struct mmc_card *card = md->queue.card; > + struct mmc_host *host = card->host; > + unsigned long flags; > > if (req && !mq->mqrq_prev->req) > /* claim host only for the first request */ > @@ -1486,6 +1484,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) > goto out; > } > > + mq->flags &= ~MMC_QUEUE_NEW_REQUEST; > if (req && req->cmd_flags & REQ_DISCARD) { > /* complete ongoing async transfer before issuing discard */ > if (card->host->areq) > @@ -1501,11 +1500,16 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) > mmc_blk_issue_rw_rq(mq, NULL); > ret = mmc_blk_issue_flush(mq, req); > } else { > + if (!req && host->areq) { > + spin_lock_irqsave(&host->context_info.lock, flags); > + host->context_info.is_waiting_last_req = true; > + spin_unlock_irqrestore(&host->context_info.lock, flags); > + } > ret = mmc_blk_issue_rw_rq(mq, req); > } > > out: > - if (!req) > + if (!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST)) > /* release host only when there are no more requests */ > mmc_release_host(card->host); > return ret; > diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c > index fadf52e..2ab21a0 100644 > --- a/drivers/mmc/card/queue.c > +++ b/drivers/mmc/card/queue.c > @@ -22,7 +22,6 @@ > > #define MMC_QUEUE_BOUNCESZ 65536 > > -#define MMC_QUEUE_SUSPENDED (1 << 0) > > /* > * Prepare a MMC request. This just filters out odd stuff. > @@ -68,6 +67,10 @@ static int mmc_queue_thread(void *d) > if (req || mq->mqrq_prev->req) { > set_current_state(TASK_RUNNING); > mq->issue_fn(mq, req); > + if (mq->flags & MMC_QUEUE_NEW_REQUEST) { > + mq->flags &= ~MMC_QUEUE_NEW_REQUEST; > + continue; /* fetch again */ > + } > > /* > * Current request becomes previous request > @@ -103,6 +106,8 @@ static void mmc_request_fn(struct request_queue *q) > { > struct mmc_queue *mq = q->queuedata; > struct request *req; > + unsigned long flags; > + struct mmc_context_info *cntx; > > if (!mq) { > while ((req = blk_fetch_request(q)) != NULL) { > @@ -112,7 +117,20 @@ static void mmc_request_fn(struct request_queue *q) > return; > } > > - if (!mq->mqrq_cur->req && !mq->mqrq_prev->req) > + cntx = &mq->card->host->context_info; > + if (!mq->mqrq_cur->req && mq->mqrq_prev->req) { > + /* > + * New MMC request arrived when MMC thread may be > + * blocked on the previous request to be complete > + * with no current request fetched > + */ > + spin_lock_irqsave(&cntx->lock, flags); > + if (cntx->is_waiting_last_req) { > + cntx->is_new_req = true; > + wake_up_interruptible(&cntx->wait); > + } > + spin_unlock_irqrestore(&cntx->lock, flags); > + } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req) > wake_up_process(mq->thread); > } > > diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h > index d2a1eb4..e20c27b 100644 > --- a/drivers/mmc/card/queue.h > +++ b/drivers/mmc/card/queue.h > @@ -27,6 +27,9 @@ struct mmc_queue { > struct task_struct *thread; > struct semaphore thread_sem; > unsigned int flags; > +#define MMC_QUEUE_SUSPENDED (1 << 0) > +#define MMC_QUEUE_NEW_REQUEST (1 << 1) > + > int (*issue_fn)(struct mmc_queue *, struct request *); > void *data; > struct request_queue *queue; > diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c > index 420cb67..e219c97 100644 > --- a/drivers/mmc/core/bus.c > +++ b/drivers/mmc/core/bus.c > @@ -321,6 +321,7 @@ int mmc_add_card(struct mmc_card *card) > #ifdef CONFIG_DEBUG_FS > mmc_add_card_debugfs(card); > #endif > + mmc_init_context_info(card->host); > > ret = device_add(&card->dev); > if (ret) > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index aaed768..614e4d8 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -319,11 +319,44 @@ out: > } > EXPORT_SYMBOL(mmc_start_bkops); > > +/* > + * mmc_wait_data_done() - done callback for data request > + * @mrq: done data request > + * > + * Wakes up mmc context, passed as a callback to host controller driver > + */ > +static void mmc_wait_data_done(struct mmc_request *mrq) > +{ > + mrq->host->context_info.is_done_rcv = true; > + wake_up_interruptible(&mrq->host->context_info.wait); > +} > + > static void mmc_wait_done(struct mmc_request *mrq) > { > complete(&mrq->completion); > } > > +/* > + *__mmc_start_data_req() - starts data request > + * @host: MMC host to start the request > + * @mrq: data request to start > + * > + * Sets the done callback to be called when request is completed by the card. > + * Starts data mmc request execution > + */ > +static int __mmc_start_data_req(struct mmc_host *host, struct mmc_request *mrq) > +{ > + mrq->done = mmc_wait_data_done; > + mrq->host = host; > + if (mmc_card_removed(host->card)) { > + mrq->cmd->error = -ENOMEDIUM; > + return -ENOMEDIUM; > + } > + mmc_start_request(host, mrq); > + > + return 0; > +} > + > static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq) > { > init_completion(&mrq->completion); > @@ -337,6 +370,62 @@ static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq) > return 0; > } > > +/* > + * mmc_wait_for_data_req_done() - wait for request completed > + * @host: MMC host to prepare the command. > + * @mrq: MMC request to wait for > + * > + * Blocks MMC context till host controller will ack end of data request > + * execution or new request notification arrives from the block layer. > + * Handles command retries. > + * > + * Returns enum mmc_blk_status after checking errors. > + */ > +static int mmc_wait_for_data_req_done(struct mmc_host *host, > + struct mmc_request *mrq, > + struct mmc_async_req *next_req) > +{ > + struct mmc_command *cmd; > + struct mmc_context_info *context_info = &host->context_info; > + int err; > + unsigned long flags; > + > + while (1) { > + wait_event_interruptible(context_info->wait, > + (context_info->is_done_rcv || > + context_info->is_new_req)); > + spin_lock_irqsave(&context_info->lock, flags); > + context_info->is_waiting_last_req = false; > + spin_unlock_irqrestore(&context_info->lock, flags); > + if (context_info->is_done_rcv) { > + context_info->is_done_rcv = false; > + context_info->is_new_req = false; > + cmd = mrq->cmd; > + if (!cmd->error || !cmd->retries || > + mmc_card_removed(host->card)) { > + err = host->areq->err_check(host->card, > + host->areq); > + break; /* return err */ > + } else { > + pr_info("%s: req failed (CMD%u): %d, retrying...\n", > + mmc_hostname(host), > + cmd->opcode, cmd->error); > + cmd->retries--; > + cmd->error = 0; > + host->ops->request(host, mrq); > + continue; /* wait for done/new event again */ > + } > + } else if (context_info->is_new_req) { > + context_info->is_new_req = false; > + if (!next_req) { > + err = MMC_BLK_NEW_REQUEST; > + break; /* return err */ > + } > + } > + } /* while */ > + return err; > +} > + > static void mmc_wait_for_req_done(struct mmc_host *host, > struct mmc_request *mrq) > { > @@ -426,8 +515,17 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host, > mmc_pre_req(host, areq->mrq, !host->areq); > > if (host->areq) { > - mmc_wait_for_req_done(host, host->areq->mrq); > - err = host->areq->err_check(host->card, host->areq); > + err = mmc_wait_for_data_req_done(host, host->areq->mrq, > + areq); > + if (err == MMC_BLK_NEW_REQUEST) { > + if (error) > + *error = err; > + /* > + * The previous request was not completed, > + * nothing to return > + */ > + return NULL; > + } > /* > * Check BKOPS urgency for each R1 response > */ > @@ -439,7 +537,7 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host, > } > > if (!err && areq) > - start_err = __mmc_start_req(host, areq->mrq); > + start_err = __mmc_start_data_req(host, areq->mrq); > > if (host->areq) > mmc_post_req(host, host->areq->mrq, 0); > @@ -2581,6 +2679,23 @@ int mmc_pm_notify(struct notifier_block *notify_block, > } > #endif > > +/** > + * mmc_init_context_info() - init synchronization context > + * @host: mmc host > + * > + * Init struct context_info needed to implement asynchronous > + * request mechanism, used by mmc core, host driver and mmc requests > + * supplier. > + */ > +void mmc_init_context_info(struct mmc_host *host) > +{ > + spin_lock_init(&host->context_info.lock); > + host->context_info.is_new_req = false; > + host->context_info.is_done_rcv = false; > + host->context_info.is_waiting_last_req = false; > + init_waitqueue_head(&host->context_info.wait); > +} > + > static int __init mmc_init(void) > { > int ret; > diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h > index 3bdafbc..0272b32 100644 > --- a/drivers/mmc/core/core.h > +++ b/drivers/mmc/core/core.h > @@ -76,5 +76,6 @@ void mmc_remove_host_debugfs(struct mmc_host *host); > void mmc_add_card_debugfs(struct mmc_card *card); > void mmc_remove_card_debugfs(struct mmc_card *card); > > +void mmc_init_context_info(struct mmc_host *host); > #endif > > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 5c69315..be2500a 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -187,6 +187,18 @@ struct sdio_func_tuple; > > #define SDIO_MAX_FUNCS 7 > > +enum mmc_blk_status { > + MMC_BLK_SUCCESS = 0, > + MMC_BLK_PARTIAL, > + MMC_BLK_CMD_ERR, > + MMC_BLK_RETRY, > + MMC_BLK_ABORT, > + MMC_BLK_DATA_ERR, > + MMC_BLK_ECC_ERR, > + MMC_BLK_NOMEDIUM, > + MMC_BLK_NEW_REQUEST, > +}; > + > /* The number of MMC physical partitions. These consist of: > * boot partitions (2), general purpose partitions (4) in MMC v4.4. > */ > diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h > index 5bf7c22..495d133 100644 > --- a/include/linux/mmc/core.h > +++ b/include/linux/mmc/core.h > @@ -120,6 +120,7 @@ struct mmc_data { > s32 host_cookie; /* host private data */ > }; > > +struct mmc_host; > struct mmc_request { > struct mmc_command *sbc; /* SET_BLOCK_COUNT for multiblock */ > struct mmc_command *cmd; > @@ -128,9 +129,9 @@ struct mmc_request { > > struct completion completion; > void (*done)(struct mmc_request *);/* completion function */ > + struct mmc_host *host; > }; > > -struct mmc_host; > struct mmc_card; > struct mmc_async_req; > > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 61a10c1..82bf1a8 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -170,6 +170,22 @@ struct mmc_slot { > void *handler_priv; > }; > > +/** > + * mmc_context_info - synchronization details for mmc context > + * @is_done_rcv wake up reason was done request > + * @is_new_req wake up reason was new request > + * @is_waiting_last_req mmc context waiting for single running request > + * @wait wait queue > + * @lock lock to protect data fields > + */ > +struct mmc_context_info { > + bool is_done_rcv; > + bool is_new_req; > + bool is_waiting_last_req; > + wait_queue_head_t wait; > + spinlock_t lock; > +}; > + > struct regulator; > > struct mmc_supply { > @@ -331,6 +347,7 @@ struct mmc_host { > struct dentry *debugfs_root; > > struct mmc_async_req *areq; /* active async req */ > + struct mmc_context_info context_info; /* async synchronization info */ > > #ifdef CONFIG_FAIL_MMC_REQUEST > struct fault_attr fail_mmc_request; > -- > 1.7.6 > -- > Konstantin Dorfman, > QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, > Inc. is a member of Code Aurora Forum, > hosted by The Linux Foundation > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 21056b9..f79b468 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -113,17 +113,6 @@ struct mmc_blk_data { static DEFINE_MUTEX(open_lock); -enum mmc_blk_status { - MMC_BLK_SUCCESS = 0, - MMC_BLK_PARTIAL, - MMC_BLK_CMD_ERR, - MMC_BLK_RETRY, - MMC_BLK_ABORT, - MMC_BLK_DATA_ERR, - MMC_BLK_ECC_ERR, - MMC_BLK_NOMEDIUM, -}; - module_param(perdev_minors, int, 0444); MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device"); @@ -1364,8 +1353,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc) } else areq = NULL; areq = mmc_start_req(card->host, areq, (int *) &status); - if (!areq) + if (!areq) { + if (status == MMC_BLK_NEW_REQUEST) + mq->flags |= MMC_QUEUE_NEW_REQUEST; return 0; + } mq_rq = container_of(areq, struct mmc_queue_req, mmc_active); brq = &mq_rq->brq; @@ -1438,6 +1430,10 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc) break; case MMC_BLK_NOMEDIUM: goto cmd_abort; + default: + pr_err("%s: Unhandled return value (%d)", + req->rq_disk->disk_name, status); + goto cmd_abort; } if (ret) { @@ -1472,6 +1468,8 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) int ret; struct mmc_blk_data *md = mq->data; struct mmc_card *card = md->queue.card; + struct mmc_host *host = card->host; + unsigned long flags; if (req && !mq->mqrq_prev->req) /* claim host only for the first request */ @@ -1486,6 +1484,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) goto out; } + mq->flags &= ~MMC_QUEUE_NEW_REQUEST; if (req && req->cmd_flags & REQ_DISCARD) { /* complete ongoing async transfer before issuing discard */ if (card->host->areq) @@ -1501,11 +1500,16 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) mmc_blk_issue_rw_rq(mq, NULL); ret = mmc_blk_issue_flush(mq, req); } else { + if (!req && host->areq) { + spin_lock_irqsave(&host->context_info.lock, flags); + host->context_info.is_waiting_last_req = true; + spin_unlock_irqrestore(&host->context_info.lock, flags); + } ret = mmc_blk_issue_rw_rq(mq, req); } out: - if (!req) + if (!req && !(mq->flags & MMC_QUEUE_NEW_REQUEST)) /* release host only when there are no more requests */ mmc_release_host(card->host); return ret; diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index fadf52e..2ab21a0 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -22,7 +22,6 @@ #define MMC_QUEUE_BOUNCESZ 65536 -#define MMC_QUEUE_SUSPENDED (1 << 0) /* * Prepare a MMC request. This just filters out odd stuff. @@ -68,6 +67,10 @@ static int mmc_queue_thread(void *d) if (req || mq->mqrq_prev->req) { set_current_state(TASK_RUNNING); mq->issue_fn(mq, req); + if (mq->flags & MMC_QUEUE_NEW_REQUEST) { + mq->flags &= ~MMC_QUEUE_NEW_REQUEST; + continue; /* fetch again */ + } /* * Current request becomes previous request @@ -103,6 +106,8 @@ static void mmc_request_fn(struct request_queue *q) { struct mmc_queue *mq = q->queuedata; struct request *req; + unsigned long flags; + struct mmc_context_info *cntx; if (!mq) { while ((req = blk_fetch_request(q)) != NULL) { @@ -112,7 +117,20 @@ static void mmc_request_fn(struct request_queue *q) return; } - if (!mq->mqrq_cur->req && !mq->mqrq_prev->req) + cntx = &mq->card->host->context_info; + if (!mq->mqrq_cur->req && mq->mqrq_prev->req) { + /* + * New MMC request arrived when MMC thread may be + * blocked on the previous request to be complete + * with no current request fetched + */ + spin_lock_irqsave(&cntx->lock, flags); + if (cntx->is_waiting_last_req) { + cntx->is_new_req = true; + wake_up_interruptible(&cntx->wait); + } + spin_unlock_irqrestore(&cntx->lock, flags); + } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req) wake_up_process(mq->thread); } diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h index d2a1eb4..e20c27b 100644 --- a/drivers/mmc/card/queue.h +++ b/drivers/mmc/card/queue.h @@ -27,6 +27,9 @@ struct mmc_queue { struct task_struct *thread; struct semaphore thread_sem; unsigned int flags; +#define MMC_QUEUE_SUSPENDED (1 << 0) +#define MMC_QUEUE_NEW_REQUEST (1 << 1) + int (*issue_fn)(struct mmc_queue *, struct request *); void *data; struct request_queue *queue; diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c index 420cb67..e219c97 100644 --- a/drivers/mmc/core/bus.c +++ b/drivers/mmc/core/bus.c @@ -321,6 +321,7 @@ int mmc_add_card(struct mmc_card *card) #ifdef CONFIG_DEBUG_FS mmc_add_card_debugfs(card); #endif + mmc_init_context_info(card->host); ret = device_add(&card->dev); if (ret) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index aaed768..614e4d8 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -319,11 +319,44 @@ out: } EXPORT_SYMBOL(mmc_start_bkops); +/* + * mmc_wait_data_done() - done callback for data request + * @mrq: done data request + * + * Wakes up mmc context, passed as a callback to host controller driver + */ +static void mmc_wait_data_done(struct mmc_request *mrq) +{ + mrq->host->context_info.is_done_rcv = true; + wake_up_interruptible(&mrq->host->context_info.wait); +} + static void mmc_wait_done(struct mmc_request *mrq) { complete(&mrq->completion); } +/* + *__mmc_start_data_req() - starts data request + * @host: MMC host to start the request + * @mrq: data request to start + * + * Sets the done callback to be called when request is completed by the card. + * Starts data mmc request execution + */ +static int __mmc_start_data_req(struct mmc_host *host, struct mmc_request *mrq) +{ + mrq->done = mmc_wait_data_done; + mrq->host = host; + if (mmc_card_removed(host->card)) { + mrq->cmd->error = -ENOMEDIUM; + return -ENOMEDIUM; + } + mmc_start_request(host, mrq); + + return 0; +} + static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq) { init_completion(&mrq->completion); @@ -337,6 +370,62 @@ static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq) return 0; } +/* + * mmc_wait_for_data_req_done() - wait for request completed + * @host: MMC host to prepare the command. + * @mrq: MMC request to wait for + * + * Blocks MMC context till host controller will ack end of data request + * execution or new request notification arrives from the block layer. + * Handles command retries. + * + * Returns enum mmc_blk_status after checking errors. + */ +static int mmc_wait_for_data_req_done(struct mmc_host *host, + struct mmc_request *mrq, + struct mmc_async_req *next_req) +{ + struct mmc_command *cmd; + struct mmc_context_info *context_info = &host->context_info; + int err; + unsigned long flags; + + while (1) { + wait_event_interruptible(context_info->wait, + (context_info->is_done_rcv || + context_info->is_new_req)); + spin_lock_irqsave(&context_info->lock, flags); + context_info->is_waiting_last_req = false; + spin_unlock_irqrestore(&context_info->lock, flags); + if (context_info->is_done_rcv) { + context_info->is_done_rcv = false; + context_info->is_new_req = false; + cmd = mrq->cmd; + if (!cmd->error || !cmd->retries || + mmc_card_removed(host->card)) { + err = host->areq->err_check(host->card, + host->areq); + break; /* return err */ + } else { + pr_info("%s: req failed (CMD%u): %d, retrying...\n", + mmc_hostname(host), + cmd->opcode, cmd->error); + cmd->retries--; + cmd->error = 0; + host->ops->request(host, mrq); + continue; /* wait for done/new event again */ + } + } else if (context_info->is_new_req) { + context_info->is_new_req = false; + if (!next_req) { + err = MMC_BLK_NEW_REQUEST; + break; /* return err */ + } + } + } /* while */ + return err; +} + static void mmc_wait_for_req_done(struct mmc_host *host, struct mmc_request *mrq) { @@ -426,8 +515,17 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host, mmc_pre_req(host, areq->mrq, !host->areq); if (host->areq) { - mmc_wait_for_req_done(host, host->areq->mrq); - err = host->areq->err_check(host->card, host->areq); + err = mmc_wait_for_data_req_done(host, host->areq->mrq, + areq); + if (err == MMC_BLK_NEW_REQUEST) { + if (error) + *error = err; + /* + * The previous request was not completed, + * nothing to return + */ + return NULL; + } /* * Check BKOPS urgency for each R1 response */ @@ -439,7 +537,7 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host, } if (!err && areq) - start_err = __mmc_start_req(host, areq->mrq); + start_err = __mmc_start_data_req(host, areq->mrq); if (host->areq) mmc_post_req(host, host->areq->mrq, 0); @@ -2581,6 +2679,23 @@ int mmc_pm_notify(struct notifier_block *notify_block, } #endif +/** + * mmc_init_context_info() - init synchronization context + * @host: mmc host + * + * Init struct context_info needed to implement asynchronous + * request mechanism, used by mmc core, host driver and mmc requests + * supplier. + */ +void mmc_init_context_info(struct mmc_host *host) +{ + spin_lock_init(&host->context_info.lock); + host->context_info.is_new_req = false; + host->context_info.is_done_rcv = false; + host->context_info.is_waiting_last_req = false; + init_waitqueue_head(&host->context_info.wait); +} + static int __init mmc_init(void) { int ret; diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h index 3bdafbc..0272b32 100644 --- a/drivers/mmc/core/core.h +++ b/drivers/mmc/core/core.h @@ -76,5 +76,6 @@ void mmc_remove_host_debugfs(struct mmc_host *host); void mmc_add_card_debugfs(struct mmc_card *card); void mmc_remove_card_debugfs(struct mmc_card *card); +void mmc_init_context_info(struct mmc_host *host); #endif diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 5c69315..be2500a 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -187,6 +187,18 @@ struct sdio_func_tuple; #define SDIO_MAX_FUNCS 7 +enum mmc_blk_status { + MMC_BLK_SUCCESS = 0, + MMC_BLK_PARTIAL, + MMC_BLK_CMD_ERR, + MMC_BLK_RETRY, + MMC_BLK_ABORT, + MMC_BLK_DATA_ERR, + MMC_BLK_ECC_ERR, + MMC_BLK_NOMEDIUM, + MMC_BLK_NEW_REQUEST, +}; + /* The number of MMC physical partitions. These consist of: * boot partitions (2), general purpose partitions (4) in MMC v4.4. */ diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h index 5bf7c22..495d133 100644 --- a/include/linux/mmc/core.h +++ b/include/linux/mmc/core.h @@ -120,6 +120,7 @@ struct mmc_data { s32 host_cookie; /* host private data */ }; +struct mmc_host; struct mmc_request { struct mmc_command *sbc; /* SET_BLOCK_COUNT for multiblock */ struct mmc_command *cmd; @@ -128,9 +129,9 @@ struct mmc_request { struct completion completion; void (*done)(struct mmc_request *);/* completion function */ + struct mmc_host *host; }; -struct mmc_host; struct mmc_card; struct mmc_async_req; diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 61a10c1..82bf1a8 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -170,6 +170,22 @@ struct mmc_slot { void *handler_priv; }; +/** + * mmc_context_info - synchronization details for mmc context + * @is_done_rcv wake up reason was done request + * @is_new_req wake up reason was new request + * @is_waiting_last_req mmc context waiting for single running request + * @wait wait queue + * @lock lock to protect data fields + */ +struct mmc_context_info { + bool is_done_rcv; + bool is_new_req; + bool is_waiting_last_req; + wait_queue_head_t wait; + spinlock_t lock; +}; + struct regulator; struct mmc_supply { @@ -331,6 +347,7 @@ struct mmc_host { struct dentry *debugfs_root; struct mmc_async_req *areq; /* active async req */ + struct mmc_context_info context_info; /* async synchronization info */ #ifdef CONFIG_FAIL_MMC_REQUEST struct fault_attr fail_mmc_request;

[v5] mmc: fix async request mechanism for sequential read scenarios

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