From 2ff1fa679115e3c8c78ad74ad8fd2d7fd87ae4e7 Mon Sep 17 00:00:00 2001 From: Pierre Ossman Date: Tue, 22 Jul 2008 14:35:42 +0200 Subject: [PATCH] mmc_block: bounce buffer highmem support Support highmem pages in the bounce buffer code by using the sg_copy_from/to_buffer() functions. Signed-off-by: Pierre Ossman --- drivers/mmc/card/queue.c | 97 +++++++++++++--------------------------- 1 file changed, 31 insertions(+), 66 deletions(-) diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index 7731ddefdc1..3dee97e7d16 100644 --- a/drivers/mmc/card/queue.c +++ b/drivers/mmc/card/queue.c @@ -148,7 +148,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock 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_bounce_limit(mq->queue, BLK_BOUNCE_ANY); 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); @@ -290,55 +290,15 @@ void mmc_queue_resume(struct mmc_queue *mq) } } -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(src); - 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--; - } - } -} - +/* + * Prepare the sg list(s) to be handed of to the host driver + */ unsigned int mmc_queue_map_sg(struct mmc_queue *mq) { unsigned int sg_len; + size_t buflen; + struct scatterlist *sg; + int i; if (!mq->bounce_buf) return blk_rq_map_sg(mq->queue, mq->req, mq->sg); @@ -349,47 +309,52 @@ unsigned int mmc_queue_map_sg(struct mmc_queue *mq) 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; - } + buflen = 0; + for_each_sg(mq->bounce_sg, sg, sg_len, i) + buflen += sg->length; - 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--; - } + sg_init_one(mq->sg, mq->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 *mq) { + unsigned long flags; + 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); + local_irq_save(flags); + sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len, + mq->bounce_buf, mq->sg[0].length); + local_irq_restore(flags); } +/* + * 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 *mq) { + unsigned long flags; + 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); + local_irq_save(flags); + sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len, + mq->bounce_buf, mq->sg[0].length); + local_irq_restore(flags); } -- 2.20.1