1 files changed, 489 insertions, 0 deletions

diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
new file mode 100644
index 000000000000..f4e3d76792f3
--- /dev/null
+++ b/drivers/mmc/core/queue.c
@@ -0,0 +1,489 @@
+/*
+ *  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"
+
+#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->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_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->cmd_flags |= REQ_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(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);
+        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);
+}