/* * 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/dma-mapping.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> #include "queue.h" #include "block.h" #include "core.h" #include "card.h" #define MMC_QUEUE_BOUNCESZ 65536 /* * 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_op(req) != REQ_OP_DISCARD && req_op(req) != REQ_OP_SECURE_ERASE) { blk_dump_rq_flags(req, "MMC bad request"); return BLKPREP_KILL; } if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq))) return BLKPREP_KILL; req->rq_flags |= RQF_DONTPREP; return BLKPREP_OK; } static int mmc_queue_thread(void *d) { struct mmc_queue *mq = d; struct request_queue *q = mq->queue; struct mmc_context_info *cntx = &mq->card->host->context_info; current->flags |= PF_MEMALLOC; down(&mq->thread_sem); do { struct request *req = NULL; spin_lock_irq(q->queue_lock); set_current_state(TASK_INTERRUPTIBLE); req = blk_fetch_request(q); mq->asleep = false; cntx->is_waiting_last_req = false; cntx->is_new_req = false; if (!req) { /* * Dispatch queue is empty so set flags for * mmc_request_fn() to wake us up. */ if (mq->mqrq_prev->req) cntx->is_waiting_last_req = true; else mq->asleep = true; } mq->mqrq_cur->req = req; spin_unlock_irq(q->queue_lock); if (req || mq->mqrq_prev->req) { bool req_is_special = mmc_req_is_special(req); set_current_state(TASK_RUNNING); mmc_blk_issue_rq(mq, req); cond_resched(); if (mq->flags & MMC_QUEUE_NEW_REQUEST) { mq->flags &= ~MMC_QUEUE_NEW_REQUEST; continue; /* fetch again */ } /* * Current request becomes previous request * and vice versa. * In case of special requests, current request * has been finished. Do not assign it to previous * request. */ if (req_is_special) mq->mqrq_cur->req = NULL; mq->mqrq_prev->brq.mrq.data = NULL; mq->mqrq_prev->req = NULL; swap(mq->mqrq_prev, mq->mqrq_cur); } else { if (kthread_should_stop()) { set_current_state(TASK_RUNNING); break; } 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_fn(struct request_queue *q) { struct mmc_queue *mq = q->queuedata; struct request *req; struct mmc_context_info *cntx; if (!mq) { while ((req = blk_fetch_request(q)) != NULL) { req->rq_flags |= RQF_QUIET; __blk_end_request_all(req, -EIO); } return; } cntx = &mq->card->host->context_info; if (cntx->is_waiting_last_req) { cntx->is_new_req = true; wake_up_interruptible(&cntx->wait); } if (mq->asleep) wake_up_process(mq->thread); } static struct scatterlist *mmc_alloc_sg(int sg_len, int *err) { struct scatterlist *sg; sg = kmalloc_array(sg_len, sizeof(*sg), 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); blk_queue_max_discard_sectors(q, 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_SECERASE, q); } #ifdef CONFIG_MMC_BLOCK_BOUNCE static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq, unsigned int bouncesz) { int i; for (i = 0; i < mq->qdepth; i++) { mq->mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL); if (!mq->mqrq[i].bounce_buf) goto out_err; } return true; out_err: while (--i >= 0) { kfree(mq->mqrq[i].bounce_buf); mq->mqrq[i].bounce_buf = NULL; } pr_warn("%s: unable to allocate bounce buffers\n", mmc_card_name(mq->card)); return false; } static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq, unsigned int bouncesz) { int i, ret; for (i = 0; i < mq->qdepth; i++) { mq->mqrq[i].sg = mmc_alloc_sg(1, &ret); if (ret) return ret; mq->mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret); if (ret) return ret; } return 0; } #endif static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs) { int i, ret; for (i = 0; i < mq->qdepth; i++) { mq->mqrq[i].sg = mmc_alloc_sg(max_segs, &ret); if (ret) return ret; } return 0; } static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq) { kfree(mqrq->bounce_sg); mqrq->bounce_sg = NULL; kfree(mqrq->sg); mqrq->sg = NULL; kfree(mqrq->bounce_buf); mqrq->bounce_buf = NULL; } static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq) { int i; for (i = 0; i < mq->qdepth; i++) mmc_queue_req_free_bufs(&mq->mqrq[i]); } /** * 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; bool bounce = false; int ret = -ENOMEM; if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT; mq->card = card; mq->queue = blk_init_queue(mmc_request_fn, lock); if (!mq->queue) return -ENOMEM; mq->qdepth = 2; mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req), GFP_KERNEL); if (!mq->mqrq) goto blk_cleanup; mq->mqrq_cur = &mq->mqrq[0]; mq->mqrq_prev = &mq->mqrq[1]; mq->queue->queuedata = mq; blk_queue_prep_rq(mq->queue, mmc_prep_request); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue); if (mmc_can_erase(card)) mmc_queue_setup_discard(mq->queue, card); #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 && mmc_queue_alloc_bounce_bufs(mq, bouncesz)) { 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); ret = mmc_queue_alloc_bounce_sgs(mq, bouncesz); if (ret) goto cleanup_queue; bounce = true; } } #endif if (!bounce) { 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_segments(mq->queue, host->max_segs); blk_queue_max_segment_size(mq->queue, host->max_seg_size); ret = mmc_queue_alloc_sgs(mq, host->max_segs); if (ret) goto cleanup_queue; } 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 cleanup_queue; } return 0; cleanup_queue: mmc_queue_reqs_free_bufs(mq); kfree(mq->mqrq); mq->mqrq = NULL; blk_cleanup: blk_cleanup_queue(mq->queue); return ret; } void mmc_cleanup_queue(struct mmc_queue *mq) { struct request_queue *q = mq->queue; unsigned long flags; /* 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); mmc_queue_reqs_free_bufs(mq); kfree(mq->mqrq); mq->mqrq = NULL; mq->card = NULL; } EXPORT_SYMBOL(mmc_cleanup_queue); /** * mmc_queue_suspend - suspend a MMC request queue * @mq: MMC queue to suspend * * 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. */ void mmc_queue_suspend(struct mmc_queue *mq) { struct request_queue *q = mq->queue; unsigned long flags; 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); down(&mq->thread_sem); } } /** * 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); } } /* * 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) return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg); 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); }