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>
ubi->min_io_size = ubi->mtd->writesize;
ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
ubi->min_io_size = ubi->mtd->writesize;
ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
- /* Make sure minimal I/O unit is power of 2 */
+ /*
+ * Make sure minimal I/O unit is power of 2. Note, there is no
+ * fundamental reason for this assumption. It is just an optimization
+ * which allows us to avoid costly division operations.
+ */
if (!is_power_of_2(ubi->min_io_size)) {
ubi_err("min. I/O unit (%d) is not power of 2",
ubi->min_io_size);
if (!is_power_of_2(ubi->min_io_size)) {
ubi_err("min. I/O unit (%d) is not power of 2",
ubi->min_io_size);
if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
- ubi->leb_start % ubi->min_io_size) {
+ ubi->leb_start & (ubi->min_io_size - 1)) {
ubi_err("bad VID header (%d) or data offsets (%d)",
ubi->vid_hdr_offset, ubi->leb_start);
return -EINVAL;
ubi_err("bad VID header (%d) or data offsets (%d)",
ubi->vid_hdr_offset, ubi->leb_start);
return -EINVAL;
off = do_div(tmp, vol->usable_leb_size);
lnum = tmp;
off = do_div(tmp, vol->usable_leb_size);
lnum = tmp;
- if (off % ubi->min_io_size) {
+ if (off & (ubi->min_io_size - 1)) {
dbg_err("unaligned position");
return -EINVAL;
}
dbg_err("unaligned position");
return -EINVAL;
}
count_save = count = vol->used_bytes - *offp;
/* We can write only in fractions of the minimum I/O unit */
count_save = count = vol->used_bytes - *offp;
/* We can write only in fractions of the minimum I/O unit */
- if (count % ubi->min_io_size) {
+ if (count & (ubi->min_io_size - 1)) {
dbg_err("unaligned write length");
return -EINVAL;
}
dbg_err("unaligned write length");
return -EINVAL;
}
if (req->alignment > ubi->leb_size)
goto bad;
if (req->alignment > ubi->leb_size)
goto bad;
- n = req->alignment % ubi->min_io_size;
+ n = req->alignment & (ubi->min_io_size - 1);
if (req->alignment != 1 && n)
goto bad;
if (req->alignment != 1 && n)
goto bad;
/* If this is the last LEB @len may be unaligned */
len = ALIGN(data_size, ubi->min_io_size);
else
/* If this is the last LEB @len may be unaligned */
len = ALIGN(data_size, ubi->min_io_size);
else
- ubi_assert(len % ubi->min_io_size == 0);
+ ubi_assert(!(len & (ubi->min_io_size - 1)));
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
- offset + len > vol->usable_leb_size || offset % ubi->min_io_size ||
- len % ubi->min_io_size)
+ offset + len > vol->usable_leb_size ||
+ offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
return -EINVAL;
if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
return -EINVAL;
if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
- len > vol->usable_leb_size || len % ubi->min_io_size)
+ len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
return -EINVAL;
if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
return -EINVAL;
if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
- ubi_assert(length % ubi->min_io_size == 0);
+ ubi_assert(!(length & (ubi->min_io_size - 1)));
for (i = length - 1; i >= 0; i--)
if (((const uint8_t *)buf)[i] != 0xFF)
for (i = length - 1; i >= 0; i--)
if (((const uint8_t *)buf)[i] != 0xFF)
- n = vol->alignment % ubi->min_io_size;
+ n = vol->alignment & (ubi->min_io_size - 1);
if (vol->alignment != 1 && n) {
ubi_err("alignment is not multiple of min I/O unit");
goto fail;
if (vol->alignment != 1 && n) {
ubi_err("alignment is not multiple of min I/O unit");
goto fail;
- n = alignment % ubi->min_io_size;
+ n = alignment & (ubi->min_io_size - 1);
if (alignment != 1 && n) {
err = 5;
goto bad;
if (alignment != 1 && n) {
err = 5;
goto bad;
- if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&&
+ if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
si->highest_vol_id < UBI_INTERNAL_VOL_START) {
ubi_err("too large volume ID %d found by scanning",
si->highest_vol_id);
return -EINVAL;
}
si->highest_vol_id < UBI_INTERNAL_VOL_START) {
ubi_err("too large volume ID %d found by scanning",
si->highest_vol_id);
return -EINVAL;
}
for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
cond_resched();
for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
cond_resched();
int err;
if (kthread_should_stop())
int err;
if (kthread_should_stop())
if (try_to_freeze())
continue;
if (try_to_freeze())
continue;
dbg_wl("background thread \"%s\" is killed", ubi->bgt_name);
return 0;
}
dbg_wl("background thread \"%s\" is killed", ubi->bgt_name);
return 0;
}