/*
- * linux/drivers/mmc/queue.c
+ * linux/drivers/mmc/card/queue.c
*
* Copyright (C) 2003 Russell King, All Rights Reserved.
* Copyright 2006-2007 Pierre Ossman
*/
#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
+
#define MMC_QUEUE_SUSPENDED (1 << 0)
/*
- * Prepare a MMC request. Essentially, this means passing the
- * preparation off to the media driver. The media driver will
- * create a mmc_io_request in req->special.
+ * 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;
- int ret = BLKPREP_KILL;
-
- if (blk_special_request(req)) {
- /*
- * Special commands already have the command
- * blocks already setup in req->special.
- */
- BUG_ON(!req->special);
-
- ret = BLKPREP_OK;
- } else if (blk_fs_request(req) || blk_pc_request(req)) {
- /*
- * Block I/O requests need translating according
- * to the protocol.
- */
- ret = mq->prep_fn(mq, req);
- } else {
- /*
- * Everything else is invalid.
- */
+ /*
+ * We only like normal block requests.
+ */
+ if (!blk_fs_request(req) && !blk_pc_request(req)) {
blk_dump_rq_flags(req, "MMC bad request");
+ return BLKPREP_KILL;
}
- if (ret == BLKPREP_OK)
- req->cmd_flags |= REQ_DONTPREP;
+ req->cmd_flags |= REQ_DONTPREP;
- return ret;
+ return BLKPREP_OK;
}
static int mmc_queue_thread(void *d)
struct mmc_queue *mq = d;
struct request_queue *q = mq->queue;
- /*
- * Set iothread to ensure that we aren't put to sleep by
- * the process freezing. We handle suspension ourselves.
- */
- current->flags |= PF_MEMALLOC|PF_NOFREEZE;
+ current->flags |= PF_MEMALLOC;
down(&mq->thread_sem);
do {
* 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(request_queue_t *q)
+static void mmc_request(struct request_queue *q)
{
struct mmc_queue *mq = q->queuedata;
struct request *req;
if (!mq->queue)
return -ENOMEM;
- blk_queue_prep_rq(mq->queue, mmc_prep_request);
- blk_queue_bounce_limit(mq->queue, limit);
- blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
- blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
- blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
- blk_queue_max_segment_size(mq->queue, host->max_seg_size);
-
mq->queue->queuedata = mq;
mq->req = NULL;
- mq->sg = kmalloc(sizeof(struct scatterlist) * host->max_phys_segs,
- GFP_KERNEL);
- if (!mq->sg) {
- ret = -ENOMEM;
- goto cleanup_queue;
+ blk_queue_prep_rq(mq->queue, mmc_prep_request);
+
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+ if (host->max_hw_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;
+
+ mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+ if (!mq->bounce_buf) {
+ printk(KERN_WARNING "%s: unable to allocate "
+ "bounce buffer\n", mmc_card_name(card));
+ } else {
+ blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
+ blk_queue_max_sectors(mq->queue, bouncesz / 512);
+ blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
+ blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
+ blk_queue_max_segment_size(mq->queue, bouncesz);
+
+ mq->sg = kmalloc(sizeof(struct scatterlist),
+ GFP_KERNEL);
+ if (!mq->sg) {
+ ret = -ENOMEM;
+ goto cleanup_queue;
+ }
+ sg_init_table(mq->sg, 1);
+
+ mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
+ bouncesz / 512, GFP_KERNEL);
+ if (!mq->bounce_sg) {
+ ret = -ENOMEM;
+ goto cleanup_queue;
+ }
+ sg_init_table(mq->bounce_sg, bouncesz / 512);
+ }
+ }
+#endif
+
+ if (!mq->bounce_buf) {
+ blk_queue_bounce_limit(mq->queue, limit);
+ blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
+ blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
+ blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
+ blk_queue_max_segment_size(mq->queue, host->max_seg_size);
+
+ mq->sg = kzalloc(sizeof(struct scatterlist) *
+ host->max_phys_segs, GFP_KERNEL);
+ if (!mq->sg) {
+ ret = -ENOMEM;
+ goto cleanup_queue;
+ }
}
init_MUTEX(&mq->thread_sem);
mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
if (IS_ERR(mq->thread)) {
ret = PTR_ERR(mq->thread);
- goto free_sg;
+ goto free_bounce_sg;
}
return 0;
-
- free_sg:
- kfree(mq->sg);
- mq->sg = NULL;
+ free_bounce_sg:
+ if (mq->bounce_sg)
+ kfree(mq->bounce_sg);
+ mq->bounce_sg = NULL;
cleanup_queue:
+ if (mq->sg)
+ kfree(mq->sg);
+ mq->sg = NULL;
+ if (mq->bounce_buf)
+ kfree(mq->bounce_buf);
+ mq->bounce_buf = NULL;
blk_cleanup_queue(mq->queue);
return ret;
}
void mmc_cleanup_queue(struct mmc_queue *mq)
{
- request_queue_t *q = mq->queue;
+ struct request_queue *q = mq->queue;
unsigned long flags;
/* Mark that we should start throwing out stragglers */
q->queuedata = NULL;
spin_unlock_irqrestore(q->queue_lock, 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);
+ if (mq->bounce_sg)
+ kfree(mq->bounce_sg);
+ mq->bounce_sg = NULL;
+
kfree(mq->sg);
mq->sg = NULL;
+ if (mq->bounce_buf)
+ kfree(mq->bounce_buf);
+ mq->bounce_buf = NULL;
+
blk_cleanup_queue(mq->queue);
mq->card = NULL;
*/
void mmc_queue_suspend(struct mmc_queue *mq)
{
- request_queue_t *q = mq->queue;
+ struct request_queue *q = mq->queue;
unsigned long flags;
if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
*/
void mmc_queue_resume(struct mmc_queue *mq)
{
- request_queue_t *q = mq->queue;
+ struct request_queue *q = mq->queue;
unsigned long flags;
if (mq->flags & MMC_QUEUE_SUSPENDED) {
}
}
+static void copy_sg(struct scatterlist *dst, unsigned int dst_len,
+ struct scatterlist *src, unsigned int src_len)
+{
+ unsigned int chunk;
+ char *dst_buf, *src_buf;
+ unsigned int dst_size, src_size;
+
+ dst_buf = NULL;
+ src_buf = NULL;
+ dst_size = 0;
+ src_size = 0;
+
+ while (src_len) {
+ BUG_ON(dst_len == 0);
+
+ if (dst_size == 0) {
+ dst_buf = sg_virt(dst);
+ dst_size = dst->length;
+ }
+
+ if (src_size == 0) {
+ src_buf = sg_virt(dst);
+ src_size = src->length;
+ }
+
+ chunk = min(dst_size, src_size);
+
+ memcpy(dst_buf, src_buf, chunk);
+
+ dst_buf += chunk;
+ src_buf += chunk;
+ dst_size -= chunk;
+ src_size -= chunk;
+
+ if (dst_size == 0) {
+ dst++;
+ dst_len--;
+ }
+
+ if (src_size == 0) {
+ src++;
+ src_len--;
+ }
+ }
+}
+
+unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
+{
+ unsigned int sg_len;
+
+ if (!mq->bounce_buf)
+ return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
+
+ BUG_ON(!mq->bounce_sg);
+
+ sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
+
+ mq->bounce_sg_len = sg_len;
+
+ /*
+ * Shortcut in the event we only get a single entry.
+ */
+ if (sg_len == 1) {
+ memcpy(mq->sg, mq->bounce_sg, sizeof(struct scatterlist));
+ return 1;
+ }
+
+ sg_init_one(mq->sg, mq->bounce_buf, 0);
+
+ while (sg_len) {
+ mq->sg[0].length += mq->bounce_sg[sg_len - 1].length;
+ sg_len--;
+ }
+
+ return 1;
+}
+
+void mmc_queue_bounce_pre(struct mmc_queue *mq)
+{
+ if (!mq->bounce_buf)
+ return;
+
+ if (mq->bounce_sg_len == 1)
+ return;
+ if (rq_data_dir(mq->req) != WRITE)
+ return;
+
+ copy_sg(mq->sg, 1, mq->bounce_sg, mq->bounce_sg_len);
+}
+
+void mmc_queue_bounce_post(struct mmc_queue *mq)
+{
+ if (!mq->bounce_buf)
+ return;
+
+ if (mq->bounce_sg_len == 1)
+ return;
+ if (rq_data_dir(mq->req) != READ)
+ return;
+
+ copy_sg(mq->bounce_sg, mq->bounce_sg_len, mq->sg, 1);
+}
+
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