Remove our copy of scsi_kmap_atomic_sg() and use the new helper
kmap_sg(). Since it is based on kmap_local() we can remove the
bounce buffer and perform IO while we hold the mapping.
Signed-off-by: Richard Weinberger <[email protected]>
---
drivers/mtd/ubi/eba.c | 59 +++++--------------------------------------
1 file changed, 6 insertions(+), 53 deletions(-)
diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 82c54bf7c2067..650eacab27f03 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -731,44 +731,6 @@ int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
return err;
}
-/*
- * Basically a copy of scsi_kmap_atomic_sg().
- * As long scsi_kmap_atomic_sg() is not part of lib/scatterlist.c have
- * our own version to avoid a dependency on CONFIG_SCSI.
- */
-static void *ubi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
- size_t *offset, size_t *len)
-{
- int i;
- size_t sg_len = 0, len_complete = 0;
- struct scatterlist *sg;
- struct page *page;
-
- for_each_sg(sgl, sg, sg_count, i) {
- len_complete = sg_len; /* Complete sg-entries */
- sg_len += sg->length;
- if (sg_len > *offset)
- break;
- }
-
- if (WARN_ON_ONCE(i == sg_count))
- return NULL;
-
- /* Offset starting from the beginning of first page in this sg-entry */
- *offset = *offset - len_complete + sg->offset;
-
- /* Assumption: contiguous pages can be accessed as "page + i" */
- page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
- *offset &= ~PAGE_MASK;
-
- /* Bytes in this sg-entry from *offset to the end of the page */
- sg_len = PAGE_SIZE - *offset;
- if (*len > sg_len)
- *len = sg_len;
-
- return kmap_atomic(page);
-}
-
/**
* ubi_eba_read_leb_sg - read data into a scatter gather list.
* @ubi: UBI device description object
@@ -789,17 +751,6 @@ int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
{
size_t map_len, map_offset, cur_offset;
int ret, to_read = len;
- char *bounce_buf;
-
- bounce_buf = kvmalloc(to_read, GFP_KERNEL);
- if (!bounce_buf) {
- ret = -ENOMEM;
- goto out;
- }
-
- ret = ubi_eba_read_leb(ubi, vol, lnum, bounce_buf, offset, to_read, check);
- if (ret < 0)
- goto out;
cur_offset = 0;
while (to_read > 0) {
@@ -808,9 +759,12 @@ int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
map_len = to_read;
map_offset = cur_offset + sgl->tot_offset;
- dst = ubi_kmap_atomic_sg(sgl->sg, sgl->len, &map_offset, &map_len);
- memcpy(dst + map_offset, bounce_buf + cur_offset, map_len);
- kunmap_atomic(dst);
+ dst = kmap_sg(sgl->sg, sgl->len, &map_offset, &map_len);
+ ret = ubi_eba_read_leb(ubi, vol, lnum, dst + map_offset, offset + cur_offset,
+ map_len, check);
+ if (ret < 0)
+ goto out;
+ kunmap_sg(dst);
cur_offset += map_len;
to_read -= map_len;
@@ -818,7 +772,6 @@ int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
ret = 0;
out:
- kvfree(bounce_buf);
return ret;
}
--
2.35.3