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authorNeilBrown <neilb@suse.de>2007-08-16 13:31:26 +0200
committerJens Axboe <axboe@carl.home.kernel.dk>2007-10-10 09:25:56 +0200
commiteea9befaccb8d43ce89585d612159761c978f056 (patch)
treed5db0bd4493f726d4900f13e930d25283e2c9ebe /drivers/block/umem.c
parent5705f7021748a69d84d6567e68e8851dab551464 (diff)
downloadlinux-eea9befaccb8d43ce89585d612159761c978f056.tar.bz2
Fix various abuse of bio fields in umem.c
umem.c: advances bi_idx and bi_sector to track where it is up to. But it is only ever doing this on one bio, so the updated fields can easily be kept elsewhere (current_*). updates bi_size, but never uses the updated values, so this isn't needed. reuses bi_phys_segments to count how many iovecs have been completely. As the completion happens sequentiually, we can store this information outside the bio too. Signed-off-by: Neil Brown <neilb@suse.de> diff .prev/drivers/block/umem.c ./drivers/block/umem.c Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/block/umem.c')
-rw-r--r--drivers/block/umem.c38
1 files changed, 25 insertions, 13 deletions
diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 6b7c02d6360d..c378e285d708 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -113,6 +113,8 @@ struct cardinfo {
* have been written
*/
struct bio *bio, *currentbio, **biotail;
+ int current_idx;
+ sector_t current_sector;
struct request_queue *queue;
@@ -121,6 +123,7 @@ struct cardinfo {
struct mm_dma_desc *desc;
int cnt, headcnt;
struct bio *bio, **biotail;
+ int idx;
} mm_pages[2];
#define DESC_PER_PAGE ((PAGE_SIZE*2)/sizeof(struct mm_dma_desc))
@@ -380,12 +383,16 @@ static int add_bio(struct cardinfo *card)
dma_addr_t dma_handle;
int offset;
struct bio *bio;
+ struct bio_vec *vec;
+ int idx;
int rw;
int len;
bio = card->currentbio;
if (!bio && card->bio) {
card->currentbio = card->bio;
+ card->current_idx = card->bio->bi_idx;
+ card->current_sector = card->bio->bi_sector;
card->bio = card->bio->bi_next;
if (card->bio == NULL)
card->biotail = &card->bio;
@@ -394,15 +401,17 @@ static int add_bio(struct cardinfo *card)
}
if (!bio)
return 0;
+ idx = card->current_idx;
rw = bio_rw(bio);
if (card->mm_pages[card->Ready].cnt >= DESC_PER_PAGE)
return 0;
- len = bio_iovec(bio)->bv_len;
- dma_handle = pci_map_page(card->dev,
- bio_page(bio),
- bio_offset(bio),
+ vec = bio_iovec_idx(bio, idx);
+ len = vec->bv_len;
+ dma_handle = pci_map_page(card->dev,
+ vec->bv_page,
+ vec->bv_offset,
len,
(rw==READ) ?
PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE);
@@ -410,6 +419,8 @@ static int add_bio(struct cardinfo *card)
p = &card->mm_pages[card->Ready];
desc = &p->desc[p->cnt];
p->cnt++;
+ if (p->bio == NULL)
+ p->idx = idx;
if ((p->biotail) != &bio->bi_next) {
*(p->biotail) = bio;
p->biotail = &(bio->bi_next);
@@ -419,7 +430,7 @@ static int add_bio(struct cardinfo *card)
desc->data_dma_handle = dma_handle;
desc->pci_addr = cpu_to_le64((u64)desc->data_dma_handle);
- desc->local_addr= cpu_to_le64(bio->bi_sector << 9);
+ desc->local_addr = cpu_to_le64(card->current_sector << 9);
desc->transfer_size = cpu_to_le32(len);
offset = ( ((char*)&desc->sem_control_bits) - ((char*)p->desc));
desc->sem_addr = cpu_to_le64((u64)(p->page_dma+offset));
@@ -435,10 +446,10 @@ static int add_bio(struct cardinfo *card)
desc->control_bits |= cpu_to_le32(DMASCR_TRANSFER_READ);
desc->sem_control_bits = desc->control_bits;
- bio->bi_sector += (len>>9);
- bio->bi_size -= len;
- bio->bi_idx++;
- if (bio->bi_idx >= bio->bi_vcnt)
+ card->current_sector += (len >> 9);
+ idx++;
+ card->current_idx = idx;
+ if (idx >= bio->bi_vcnt)
card->currentbio = NULL;
return 1;
@@ -474,10 +485,12 @@ static void process_page(unsigned long data)
last=1;
}
page->headcnt++;
- idx = bio->bi_phys_segments;
- bio->bi_phys_segments++;
- if (bio->bi_phys_segments >= bio->bi_vcnt)
+ idx = page->idx;
+ page->idx++;
+ if (page->idx >= bio->bi_vcnt) {
page->bio = bio->bi_next;
+ page->idx = page->bio->bi_idx;
+ }
pci_unmap_page(card->dev, desc->data_dma_handle,
bio_iovec_idx(bio,idx)->bv_len,
@@ -547,7 +560,6 @@ static int mm_make_request(struct request_queue *q, struct bio *bio)
pr_debug("mm_make_request %llu %u\n",
(unsigned long long)bio->bi_sector, bio->bi_size);
- bio->bi_phys_segments = bio->bi_idx; /* count of completed segments*/
spin_lock_irq(&card->lock);
*card->biotail = bio;
bio->bi_next = NULL;