diff options
author | Kyungmin Park <kyungmin.park@samsung.com> | 2008-05-21 21:32:18 -0400 |
---|---|---|
committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2008-07-24 06:32:54 -0400 |
commit | cadb40ccc16a26a738f1cbc963e35b21edd93e79 (patch) | |
tree | acd1d5d02ecda07634f1c49432ddb39cd9f5d7fd /drivers/mtd/ubi | |
parent | a0fd1efd488092951f310fdb777b8a540cf84dcb (diff) |
UBI: avoid unnecessary division operations
UBI already checks that @min io size is the power of 2 at io_init.
It is save to use bit operations then.
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/ubi')
-rw-r--r-- | drivers/mtd/ubi/build.c | 8 | ||||
-rw-r--r-- | drivers/mtd/ubi/cdev.c | 6 | ||||
-rw-r--r-- | drivers/mtd/ubi/eba.c | 2 | ||||
-rw-r--r-- | drivers/mtd/ubi/kapi.c | 6 | ||||
-rw-r--r-- | drivers/mtd/ubi/misc.c | 2 | ||||
-rw-r--r-- | drivers/mtd/ubi/vmt.c | 2 | ||||
-rw-r--r-- | drivers/mtd/ubi/vtbl.c | 5 | ||||
-rw-r--r-- | drivers/mtd/ubi/wl.c | 3 |
8 files changed, 18 insertions, 16 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 961416ac0616..ff4425de1527 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c | |||
@@ -530,7 +530,11 @@ static int io_init(struct ubi_device *ubi) | |||
530 | ubi->min_io_size = ubi->mtd->writesize; | 530 | ubi->min_io_size = ubi->mtd->writesize; |
531 | ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft; | 531 | ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft; |
532 | 532 | ||
533 | /* Make sure minimal I/O unit is power of 2 */ | 533 | /* |
534 | * Make sure minimal I/O unit is power of 2. Note, there is no | ||
535 | * fundamental reason for this assumption. It is just an optimization | ||
536 | * which allows us to avoid costly division operations. | ||
537 | */ | ||
534 | if (!is_power_of_2(ubi->min_io_size)) { | 538 | if (!is_power_of_2(ubi->min_io_size)) { |
535 | ubi_err("min. I/O unit (%d) is not power of 2", | 539 | ubi_err("min. I/O unit (%d) is not power of 2", |
536 | ubi->min_io_size); | 540 | ubi->min_io_size); |
@@ -581,7 +585,7 @@ static int io_init(struct ubi_device *ubi) | |||
581 | if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE || | 585 | if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE || |
582 | ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE || | 586 | ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE || |
583 | ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE || | 587 | ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE || |
584 | ubi->leb_start % ubi->min_io_size) { | 588 | ubi->leb_start & (ubi->min_io_size - 1)) { |
585 | ubi_err("bad VID header (%d) or data offsets (%d)", | 589 | ubi_err("bad VID header (%d) or data offsets (%d)", |
586 | ubi->vid_hdr_offset, ubi->leb_start); | 590 | ubi->vid_hdr_offset, ubi->leb_start); |
587 | return -EINVAL; | 591 | return -EINVAL; |
diff --git a/drivers/mtd/ubi/cdev.c b/drivers/mtd/ubi/cdev.c index 89193ba9451e..0cdaf9fba7b0 100644 --- a/drivers/mtd/ubi/cdev.c +++ b/drivers/mtd/ubi/cdev.c | |||
@@ -295,7 +295,7 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf, | |||
295 | off = do_div(tmp, vol->usable_leb_size); | 295 | off = do_div(tmp, vol->usable_leb_size); |
296 | lnum = tmp; | 296 | lnum = tmp; |
297 | 297 | ||
298 | if (off % ubi->min_io_size) { | 298 | if (off & (ubi->min_io_size - 1)) { |
299 | dbg_err("unaligned position"); | 299 | dbg_err("unaligned position"); |
300 | return -EINVAL; | 300 | return -EINVAL; |
301 | } | 301 | } |
@@ -304,7 +304,7 @@ static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf, | |||
304 | count_save = count = vol->used_bytes - *offp; | 304 | count_save = count = vol->used_bytes - *offp; |
305 | 305 | ||
306 | /* We can write only in fractions of the minimum I/O unit */ | 306 | /* We can write only in fractions of the minimum I/O unit */ |
307 | if (count % ubi->min_io_size) { | 307 | if (count & (ubi->min_io_size - 1)) { |
308 | dbg_err("unaligned write length"); | 308 | dbg_err("unaligned write length"); |
309 | return -EINVAL; | 309 | return -EINVAL; |
310 | } | 310 | } |
@@ -564,7 +564,7 @@ static int verify_mkvol_req(const struct ubi_device *ubi, | |||
564 | if (req->alignment > ubi->leb_size) | 564 | if (req->alignment > ubi->leb_size) |
565 | goto bad; | 565 | goto bad; |
566 | 566 | ||
567 | n = req->alignment % ubi->min_io_size; | 567 | n = req->alignment & (ubi->min_io_size - 1); |
568 | if (req->alignment != 1 && n) | 568 | if (req->alignment != 1 && n) |
569 | goto bad; | 569 | goto bad; |
570 | 570 | ||
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c index 7ce91ca742b1..37d778447943 100644 --- a/drivers/mtd/ubi/eba.c +++ b/drivers/mtd/ubi/eba.c | |||
@@ -752,7 +752,7 @@ int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol, | |||
752 | /* If this is the last LEB @len may be unaligned */ | 752 | /* If this is the last LEB @len may be unaligned */ |
753 | len = ALIGN(data_size, ubi->min_io_size); | 753 | len = ALIGN(data_size, ubi->min_io_size); |
754 | else | 754 | else |
755 | ubi_assert(len % ubi->min_io_size == 0); | 755 | ubi_assert(!(len & (ubi->min_io_size - 1))); |
756 | 756 | ||
757 | vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); | 757 | vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS); |
758 | if (!vid_hdr) | 758 | if (!vid_hdr) |
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c index a70d58823f8d..51508832566d 100644 --- a/drivers/mtd/ubi/kapi.c +++ b/drivers/mtd/ubi/kapi.c | |||
@@ -397,8 +397,8 @@ int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, | |||
397 | return -EROFS; | 397 | return -EROFS; |
398 | 398 | ||
399 | if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 || | 399 | if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 || |
400 | offset + len > vol->usable_leb_size || offset % ubi->min_io_size || | 400 | offset + len > vol->usable_leb_size || |
401 | len % ubi->min_io_size) | 401 | offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1)) |
402 | return -EINVAL; | 402 | return -EINVAL; |
403 | 403 | ||
404 | if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && | 404 | if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && |
@@ -447,7 +447,7 @@ int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, | |||
447 | return -EROFS; | 447 | return -EROFS; |
448 | 448 | ||
449 | if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 || | 449 | if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 || |
450 | len > vol->usable_leb_size || len % ubi->min_io_size) | 450 | len > vol->usable_leb_size || len & (ubi->min_io_size - 1)) |
451 | return -EINVAL; | 451 | return -EINVAL; |
452 | 452 | ||
453 | if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && | 453 | if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && |
diff --git a/drivers/mtd/ubi/misc.c b/drivers/mtd/ubi/misc.c index 93e052812012..22ad31402945 100644 --- a/drivers/mtd/ubi/misc.c +++ b/drivers/mtd/ubi/misc.c | |||
@@ -37,7 +37,7 @@ int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, | |||
37 | { | 37 | { |
38 | int i; | 38 | int i; |
39 | 39 | ||
40 | ubi_assert(length % ubi->min_io_size == 0); | 40 | ubi_assert(!(length & (ubi->min_io_size - 1))); |
41 | 41 | ||
42 | for (i = length - 1; i >= 0; i--) | 42 | for (i = length - 1; i >= 0; i--) |
43 | if (((const uint8_t *)buf)[i] != 0xFF) | 43 | if (((const uint8_t *)buf)[i] != 0xFF) |
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 5be58d85c639..7402025ded94 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c | |||
@@ -727,7 +727,7 @@ static void paranoid_check_volume(struct ubi_device *ubi, int vol_id) | |||
727 | goto fail; | 727 | goto fail; |
728 | } | 728 | } |
729 | 729 | ||
730 | n = vol->alignment % ubi->min_io_size; | 730 | n = vol->alignment & (ubi->min_io_size - 1); |
731 | if (vol->alignment != 1 && n) { | 731 | if (vol->alignment != 1 && n) { |
732 | ubi_err("alignment is not multiple of min I/O unit"); | 732 | ubi_err("alignment is not multiple of min I/O unit"); |
733 | goto fail; | 733 | goto fail; |
diff --git a/drivers/mtd/ubi/vtbl.c b/drivers/mtd/ubi/vtbl.c index 42a7815086b7..d9af11a8682b 100644 --- a/drivers/mtd/ubi/vtbl.c +++ b/drivers/mtd/ubi/vtbl.c | |||
@@ -170,7 +170,7 @@ static int vtbl_check(const struct ubi_device *ubi, | |||
170 | goto bad; | 170 | goto bad; |
171 | } | 171 | } |
172 | 172 | ||
173 | n = alignment % ubi->min_io_size; | 173 | n = alignment & (ubi->min_io_size - 1); |
174 | if (alignment != 1 && n) { | 174 | if (alignment != 1 && n) { |
175 | err = 5; | 175 | err = 5; |
176 | goto bad; | 176 | goto bad; |
@@ -684,14 +684,13 @@ static int check_scanning_info(const struct ubi_device *ubi, | |||
684 | return -EINVAL; | 684 | return -EINVAL; |
685 | } | 685 | } |
686 | 686 | ||
687 | if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&& | 687 | if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT && |
688 | si->highest_vol_id < UBI_INTERNAL_VOL_START) { | 688 | si->highest_vol_id < UBI_INTERNAL_VOL_START) { |
689 | ubi_err("too large volume ID %d found by scanning", | 689 | ubi_err("too large volume ID %d found by scanning", |
690 | si->highest_vol_id); | 690 | si->highest_vol_id); |
691 | return -EINVAL; | 691 | return -EINVAL; |
692 | } | 692 | } |
693 | 693 | ||
694 | |||
695 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { | 694 | for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) { |
696 | cond_resched(); | 695 | cond_resched(); |
697 | 696 | ||
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index a471a491f0ab..cc8fe2934d2b 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c | |||
@@ -1368,7 +1368,7 @@ int ubi_thread(void *u) | |||
1368 | int err; | 1368 | int err; |
1369 | 1369 | ||
1370 | if (kthread_should_stop()) | 1370 | if (kthread_should_stop()) |
1371 | goto out; | 1371 | break; |
1372 | 1372 | ||
1373 | if (try_to_freeze()) | 1373 | if (try_to_freeze()) |
1374 | continue; | 1374 | continue; |
@@ -1403,7 +1403,6 @@ int ubi_thread(void *u) | |||
1403 | cond_resched(); | 1403 | cond_resched(); |
1404 | } | 1404 | } |
1405 | 1405 | ||
1406 | out: | ||
1407 | dbg_wl("background thread \"%s\" is killed", ubi->bgt_name); | 1406 | dbg_wl("background thread \"%s\" is killed", ubi->bgt_name); |
1408 | return 0; | 1407 | return 0; |
1409 | } | 1408 | } |