| /* |
| * linux/drivers/mmc/card/queue.c |
| * |
| * Copyright (C) 2003 Russell King, All Rights Reserved. |
| * Copyright 2006-2007 Pierre Ossman |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| */ |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| #include <linux/blkdev.h> |
| #include <linux/freezer.h> |
| #include <linux/kthread.h> |
| #include <linux/scatterlist.h> |
| |
| #include <linux/mmc/card.h> |
| #include <linux/mmc/host.h> |
| #include "queue.h" |
| |
| #define MMC_QUEUE_BOUNCESZ 65536 |
| |
| |
| /* |
| * Based on benchmark tests the default num of requests to trigger the write |
| * packing was determined, to keep the read latency as low as possible and |
| * manage to keep the high write throughput. |
| */ |
| #define DEFAULT_NUM_REQS_TO_START_PACK 17 |
| |
| /* |
| * Prepare a MMC request. This just filters out odd stuff. |
| */ |
| static int mmc_prep_request(struct request_queue *q, struct request *req) |
| { |
| struct mmc_queue *mq = q->queuedata; |
| |
| /* |
| * We only like normal block requests and discards. |
| */ |
| if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) { |
| blk_dump_rq_flags(req, "MMC bad request"); |
| return BLKPREP_KILL; |
| } |
| |
| if (mq && mmc_card_removed(mq->card)) |
| return BLKPREP_KILL; |
| |
| req->cmd_flags |= REQ_DONTPREP; |
| |
| return BLKPREP_OK; |
| } |
| |
| static int mmc_queue_thread(void *d) |
| { |
| struct mmc_queue *mq = d; |
| struct request_queue *q = mq->queue; |
| struct mmc_card *card = mq->card; |
| |
| current->flags |= PF_MEMALLOC; |
| |
| down(&mq->thread_sem); |
| do { |
| struct mmc_queue_req *tmp; |
| struct request *req = NULL; |
| |
| spin_lock_irq(q->queue_lock); |
| set_current_state(TASK_INTERRUPTIBLE); |
| req = blk_fetch_request(q); |
| mq->mqrq_cur->req = req; |
| spin_unlock_irq(q->queue_lock); |
| |
| if (req || mq->mqrq_prev->req) { |
| set_current_state(TASK_RUNNING); |
| mq->issue_fn(mq, req); |
| if (mq->flags & MMC_QUEUE_NEW_REQUEST) { |
| continue; /* fetch again */ |
| } else if ((mq->flags & MMC_QUEUE_URGENT_REQUEST) && |
| (mq->mqrq_cur->req && |
| !(mq->mqrq_cur->req->cmd_flags & REQ_URGENT))) { |
| /* |
| * clean current request when urgent request |
| * processing in progress and current request is |
| * not urgent (all existing requests completed |
| * or reinserted to the block layer |
| */ |
| mq->mqrq_cur->brq.mrq.data = NULL; |
| mq->mqrq_cur->req = NULL; |
| } |
| |
| /* |
| * Current request becomes previous request |
| * and vice versa. |
| */ |
| mq->mqrq_prev->brq.mrq.data = NULL; |
| mq->mqrq_prev->req = NULL; |
| tmp = mq->mqrq_prev; |
| mq->mqrq_prev = mq->mqrq_cur; |
| mq->mqrq_cur = tmp; |
| } else { |
| if (kthread_should_stop()) { |
| set_current_state(TASK_RUNNING); |
| break; |
| } |
| mmc_start_delayed_bkops(card); |
| mq->card->host->context_info.is_urgent = false; |
| up(&mq->thread_sem); |
| schedule(); |
| down(&mq->thread_sem); |
| } |
| } while (1); |
| up(&mq->thread_sem); |
| |
| return 0; |
| } |
| |
| /* |
| * Generic MMC request handler. This is called for any queue on a |
| * particular host. When the host is not busy, we look for a request |
| * on any queue on this host, and attempt to issue it. This may |
| * not be the queue we were asked to process. |
| */ |
| static void mmc_request(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) { |
| req->cmd_flags |= REQ_QUIET; |
| __blk_end_request_all(req, -EIO); |
| } |
| return; |
| } |
| |
| 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); |
| } |
| |
| /* |
| * mmc_urgent_request() - Urgent MMC request handler. |
| * @q: request queue. |
| * |
| * This is called when block layer has urgent request for delivery. When mmc |
| * context is waiting for the current request to complete, it will be awaken, |
| * current request may be interrupted and re-inserted back to block device |
| * request queue. The next fetched request should be urgent request, this |
| * will be ensured by block i/o scheduler. |
| */ |
| static void mmc_urgent_request(struct request_queue *q) |
| { |
| unsigned long flags; |
| struct mmc_queue *mq = q->queuedata; |
| struct mmc_context_info *cntx; |
| |
| if (!mq) { |
| mmc_request(q); |
| return; |
| } |
| cntx = &mq->card->host->context_info; |
| |
| /* critical section with mmc_wait_data_done() */ |
| spin_lock_irqsave(&cntx->lock, flags); |
| |
| /* do stop flow only when mmc thread is waiting for done */ |
| if (mq->mqrq_cur->req || mq->mqrq_prev->req) { |
| /* |
| * Urgent request must be executed alone |
| * so disable the write packing |
| */ |
| mmc_blk_disable_wr_packing(mq); |
| cntx->is_urgent = true; |
| spin_unlock_irqrestore(&cntx->lock, flags); |
| wake_up_interruptible(&cntx->wait); |
| } else { |
| spin_unlock_irqrestore(&cntx->lock, flags); |
| mmc_request(q); |
| } |
| } |
| |
| static struct scatterlist *mmc_alloc_sg(int sg_len, int *err) |
| { |
| struct scatterlist *sg; |
| |
| sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL); |
| if (!sg) |
| *err = -ENOMEM; |
| else { |
| *err = 0; |
| sg_init_table(sg, sg_len); |
| } |
| |
| return sg; |
| } |
| |
| static void mmc_queue_setup_discard(struct request_queue *q, |
| struct mmc_card *card) |
| { |
| unsigned max_discard; |
| |
| max_discard = mmc_calc_max_discard(card); |
| if (!max_discard) |
| return; |
| |
| queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); |
| q->limits.max_discard_sectors = max_discard; |
| if (card->erased_byte == 0 && !mmc_can_discard(card)) |
| q->limits.discard_zeroes_data = 1; |
| q->limits.discard_granularity = card->pref_erase << 9; |
| /* granularity must not be greater than max. discard */ |
| if (card->pref_erase > max_discard) |
| q->limits.discard_granularity = 0; |
| if (mmc_can_secure_erase_trim(card)) |
| queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q); |
| } |
| |
| static void mmc_queue_setup_sanitize(struct request_queue *q) |
| { |
| queue_flag_set_unlocked(QUEUE_FLAG_SANITIZE, q); |
| } |
| |
| /** |
| * mmc_init_queue - initialise a queue structure. |
| * @mq: mmc queue |
| * @card: mmc card to attach this queue |
| * @lock: queue lock |
| * @subname: partition subname |
| * |
| * Initialise a MMC card request queue. |
| */ |
| int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, |
| spinlock_t *lock, const char *subname) |
| { |
| struct mmc_host *host = card->host; |
| u64 limit = BLK_BOUNCE_HIGH; |
| int ret; |
| struct mmc_queue_req *mqrq_cur = &mq->mqrq[0]; |
| struct mmc_queue_req *mqrq_prev = &mq->mqrq[1]; |
| |
| if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) |
| limit = *mmc_dev(host)->dma_mask; |
| |
| mq->card = card; |
| mq->queue = blk_init_queue(mmc_request, lock); |
| if (!mq->queue) |
| return -ENOMEM; |
| |
| if ((host->caps2 & MMC_CAP2_STOP_REQUEST) && |
| host->ops->stop_request && |
| mq->card->ext_csd.hpi_en) |
| blk_urgent_request(mq->queue, mmc_urgent_request); |
| |
| memset(&mq->mqrq_cur, 0, sizeof(mq->mqrq_cur)); |
| memset(&mq->mqrq_prev, 0, sizeof(mq->mqrq_prev)); |
| |
| INIT_LIST_HEAD(&mqrq_cur->packed_list); |
| INIT_LIST_HEAD(&mqrq_prev->packed_list); |
| |
| mq->mqrq_cur = mqrq_cur; |
| mq->mqrq_prev = mqrq_prev; |
| mq->queue->queuedata = mq; |
| mq->num_wr_reqs_to_start_packing = |
| min_t(int, (int)card->ext_csd.max_packed_writes, |
| DEFAULT_NUM_REQS_TO_START_PACK); |
| |
| blk_queue_prep_rq(mq->queue, mmc_prep_request); |
| queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); |
| if (mmc_can_erase(card)) |
| mmc_queue_setup_discard(mq->queue, card); |
| |
| /* Don't enable Sanitize if HPI is not supported */ |
| if ((mmc_can_sanitize(card) && (host->caps2 & MMC_CAP2_SANITIZE) && |
| card->ext_csd.hpi_en)) |
| mmc_queue_setup_sanitize(mq->queue); |
| |
| #ifdef CONFIG_MMC_BLOCK_BOUNCE |
| if (host->max_segs == 1) { |
| unsigned int bouncesz; |
| |
| bouncesz = MMC_QUEUE_BOUNCESZ; |
| |
| if (bouncesz > host->max_req_size) |
| bouncesz = host->max_req_size; |
| if (bouncesz > host->max_seg_size) |
| bouncesz = host->max_seg_size; |
| if (bouncesz > (host->max_blk_count * 512)) |
| bouncesz = host->max_blk_count * 512; |
| |
| if (bouncesz > 512) { |
| mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL); |
| if (!mqrq_cur->bounce_buf) { |
| pr_warning("%s: unable to " |
| "allocate bounce cur buffer\n", |
| mmc_card_name(card)); |
| } |
| mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL); |
| if (!mqrq_prev->bounce_buf) { |
| pr_warning("%s: unable to " |
| "allocate bounce prev buffer\n", |
| mmc_card_name(card)); |
| kfree(mqrq_cur->bounce_buf); |
| mqrq_cur->bounce_buf = NULL; |
| } |
| } |
| |
| if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) { |
| blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY); |
| blk_queue_max_hw_sectors(mq->queue, bouncesz / 512); |
| blk_queue_max_segments(mq->queue, bouncesz / 512); |
| blk_queue_max_segment_size(mq->queue, bouncesz); |
| |
| mqrq_cur->sg = mmc_alloc_sg(1, &ret); |
| if (ret) |
| goto cleanup_queue; |
| |
| mqrq_cur->bounce_sg = |
| mmc_alloc_sg(bouncesz / 512, &ret); |
| if (ret) |
| goto cleanup_queue; |
| |
| mqrq_prev->sg = mmc_alloc_sg(1, &ret); |
| if (ret) |
| goto cleanup_queue; |
| |
| mqrq_prev->bounce_sg = |
| mmc_alloc_sg(bouncesz / 512, &ret); |
| if (ret) |
| goto cleanup_queue; |
| } |
| } |
| #endif |
| |
| if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) { |
| unsigned int max_segs = host->max_segs; |
| |
| blk_queue_bounce_limit(mq->queue, limit); |
| blk_queue_max_hw_sectors(mq->queue, |
| min(host->max_blk_count, host->max_req_size / 512)); |
| blk_queue_max_segment_size(mq->queue, host->max_seg_size); |
| retry: |
| blk_queue_max_segments(mq->queue, host->max_segs); |
| |
| mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret); |
| if (ret == -ENOMEM) |
| goto cur_sg_alloc_failed; |
| else if (ret) |
| goto cleanup_queue; |
| |
| mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret); |
| if (ret == -ENOMEM) |
| goto prev_sg_alloc_failed; |
| else if (ret) |
| goto cleanup_queue; |
| |
| goto success; |
| |
| prev_sg_alloc_failed: |
| kfree(mqrq_cur->sg); |
| mqrq_cur->sg = NULL; |
| cur_sg_alloc_failed: |
| host->max_segs /= 2; |
| if (host->max_segs) { |
| goto retry; |
| } else { |
| host->max_segs = max_segs; |
| goto cleanup_queue; |
| } |
| } |
| |
| success: |
| sema_init(&mq->thread_sem, 1); |
| |
| mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s", |
| host->index, subname ? subname : ""); |
| |
| if (IS_ERR(mq->thread)) { |
| ret = PTR_ERR(mq->thread); |
| goto free_bounce_sg; |
| } |
| |
| return 0; |
| free_bounce_sg: |
| kfree(mqrq_cur->bounce_sg); |
| mqrq_cur->bounce_sg = NULL; |
| kfree(mqrq_prev->bounce_sg); |
| mqrq_prev->bounce_sg = NULL; |
| |
| cleanup_queue: |
| kfree(mqrq_cur->sg); |
| mqrq_cur->sg = NULL; |
| kfree(mqrq_cur->bounce_buf); |
| mqrq_cur->bounce_buf = NULL; |
| |
| kfree(mqrq_prev->sg); |
| mqrq_prev->sg = NULL; |
| kfree(mqrq_prev->bounce_buf); |
| mqrq_prev->bounce_buf = NULL; |
| |
| blk_cleanup_queue(mq->queue); |
| return ret; |
| } |
| |
| void mmc_cleanup_queue(struct mmc_queue *mq) |
| { |
| struct request_queue *q = mq->queue; |
| unsigned long flags; |
| struct mmc_queue_req *mqrq_cur = mq->mqrq_cur; |
| struct mmc_queue_req *mqrq_prev = mq->mqrq_prev; |
| |
| /* Make sure the queue isn't suspended, as that will deadlock */ |
| mmc_queue_resume(mq); |
| |
| /* Then terminate our worker thread */ |
| kthread_stop(mq->thread); |
| |
| /* Empty the queue */ |
| spin_lock_irqsave(q->queue_lock, flags); |
| q->queuedata = NULL; |
| blk_start_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| |
| kfree(mqrq_cur->bounce_sg); |
| mqrq_cur->bounce_sg = NULL; |
| |
| kfree(mqrq_cur->sg); |
| mqrq_cur->sg = NULL; |
| |
| kfree(mqrq_cur->bounce_buf); |
| mqrq_cur->bounce_buf = NULL; |
| |
| kfree(mqrq_prev->bounce_sg); |
| mqrq_prev->bounce_sg = NULL; |
| |
| kfree(mqrq_prev->sg); |
| mqrq_prev->sg = NULL; |
| |
| kfree(mqrq_prev->bounce_buf); |
| mqrq_prev->bounce_buf = NULL; |
| |
| mq->card = NULL; |
| } |
| EXPORT_SYMBOL(mmc_cleanup_queue); |
| |
| /** |
| * mmc_queue_suspend - suspend a MMC request queue |
| * @mq: MMC queue to suspend |
| * @wait: Wait till MMC request queue is empty |
| * |
| * Stop the block request queue, and wait for our thread to |
| * complete any outstanding requests. This ensures that we |
| * won't suspend while a request is being processed. |
| */ |
| int mmc_queue_suspend(struct mmc_queue *mq, int wait) |
| { |
| struct request_queue *q = mq->queue; |
| unsigned long flags; |
| int rc = 0; |
| |
| if (!(mq->flags & MMC_QUEUE_SUSPENDED)) { |
| mq->flags |= MMC_QUEUE_SUSPENDED; |
| |
| spin_lock_irqsave(q->queue_lock, flags); |
| blk_stop_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| |
| rc = down_trylock(&mq->thread_sem); |
| if (rc && !wait) { |
| /* |
| * Failed to take the lock so better to abort the |
| * suspend because mmcqd thread is processing requests. |
| */ |
| mq->flags &= ~MMC_QUEUE_SUSPENDED; |
| spin_lock_irqsave(q->queue_lock, flags); |
| blk_start_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| rc = -EBUSY; |
| } else if (rc && wait) { |
| down(&mq->thread_sem); |
| rc = 0; |
| } |
| } |
| return rc; |
| } |
| |
| /** |
| * mmc_queue_resume - resume a previously suspended MMC request queue |
| * @mq: MMC queue to resume |
| */ |
| void mmc_queue_resume(struct mmc_queue *mq) |
| { |
| struct request_queue *q = mq->queue; |
| unsigned long flags; |
| |
| if (mq->flags & MMC_QUEUE_SUSPENDED) { |
| mq->flags &= ~MMC_QUEUE_SUSPENDED; |
| |
| up(&mq->thread_sem); |
| |
| spin_lock_irqsave(q->queue_lock, flags); |
| blk_start_queue(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| } |
| } |
| |
| static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq, |
| struct mmc_queue_req *mqrq, |
| struct scatterlist *sg) |
| { |
| struct scatterlist *__sg; |
| unsigned int sg_len = 0; |
| struct request *req; |
| enum mmc_packed_cmd cmd; |
| |
| cmd = mqrq->packed_cmd; |
| |
| if (cmd == MMC_PACKED_WRITE) { |
| __sg = sg; |
| sg_set_buf(__sg, mqrq->packed_cmd_hdr, |
| sizeof(mqrq->packed_cmd_hdr)); |
| sg_len++; |
| __sg->page_link &= ~0x02; |
| } |
| |
| __sg = sg + sg_len; |
| list_for_each_entry(req, &mqrq->packed_list, queuelist) { |
| sg_len += blk_rq_map_sg(mq->queue, req, __sg); |
| __sg = sg + (sg_len - 1); |
| (__sg++)->page_link &= ~0x02; |
| } |
| sg_mark_end(sg + (sg_len - 1)); |
| return sg_len; |
| } |
| |
| /* |
| * Prepare the sg list(s) to be handed of to the host driver |
| */ |
| unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq) |
| { |
| unsigned int sg_len; |
| size_t buflen; |
| struct scatterlist *sg; |
| int i; |
| |
| if (!mqrq->bounce_buf) { |
| if (!list_empty(&mqrq->packed_list)) |
| return mmc_queue_packed_map_sg(mq, mqrq, mqrq->sg); |
| else |
| return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg); |
| } |
| |
| BUG_ON(!mqrq->bounce_sg); |
| |
| if (!list_empty(&mqrq->packed_list)) |
| sg_len = mmc_queue_packed_map_sg(mq, mqrq, mqrq->bounce_sg); |
| else |
| sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg); |
| |
| mqrq->bounce_sg_len = sg_len; |
| |
| buflen = 0; |
| for_each_sg(mqrq->bounce_sg, sg, sg_len, i) |
| buflen += sg->length; |
| |
| sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen); |
| |
| return 1; |
| } |
| |
| /* |
| * If writing, bounce the data to the buffer before the request |
| * is sent to the host driver |
| */ |
| void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq) |
| { |
| if (!mqrq->bounce_buf) |
| return; |
| |
| if (rq_data_dir(mqrq->req) != WRITE) |
| return; |
| |
| sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len, |
| mqrq->bounce_buf, mqrq->sg[0].length); |
| } |
| |
| /* |
| * If reading, bounce the data from the buffer after the request |
| * has been handled by the host driver |
| */ |
| void mmc_queue_bounce_post(struct mmc_queue_req *mqrq) |
| { |
| if (!mqrq->bounce_buf) |
| return; |
| |
| if (rq_data_dir(mqrq->req) != READ) |
| return; |
| |
| sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len, |
| mqrq->bounce_buf, mqrq->sg[0].length); |
| } |