On 2021-01-07 12:46 p.m., Jason Gunthorpe wrote:
On Mon, Dec 28, 2020 at 06:49:55PM -0500, Douglas Gilbert wrote:
The existing sg_zero_buffer() function is a bit restrictive. For
example protection information (PI) blocks are usually initialized
to 0xff bytes. As its name suggests sgl_memset() is modelled on
memset(). One difference is the type of the val argument which is
u8 rather than int. Plus it returns the number of bytes (over)written.
Change implementation of sg_zero_buffer() to call this new function.
Reviewed-by: Bodo Stroesser <bostroesser@xxxxxxxxx>
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
include/linux/scatterlist.h | 3 ++
lib/scatterlist.c | 65 +++++++++++++++++++++++++------------
2 files changed, 48 insertions(+), 20 deletions(-)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 71be65f9ebb5..70d3f1f73df1 100644
+++ b/include/linux/scatterlist.h
@@ -333,6 +333,9 @@ bool sgl_compare_sgl_idx(struct scatterlist *x_sgl, unsigned int x_nents, off_t
struct scatterlist *y_sgl, unsigned int y_nents, off_t y_skip,
size_t n_bytes, size_t *miscompare_idx);
+size_t sgl_memset(struct scatterlist *sgl, unsigned int nents, off_t skip,
+ u8 val, size_t n_bytes);
+
/*
* Maximum number of entries that will be allocated in one piece, if
* a list larger than this is required then chaining will be utilized.
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 9332365e7eb6..f06614a880c8 100644
+++ b/lib/scatterlist.c
@@ -1038,26 +1038,7 @@ EXPORT_SYMBOL(sg_pcopy_to_buffer);
size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents,
size_t buflen, off_t skip)
{
- unsigned int offset = 0;
- struct sg_mapping_iter miter;
- unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
-
- sg_miter_start(&miter, sgl, nents, sg_flags);
-
- if (!sg_miter_skip(&miter, skip))
- return false;
-
- while (offset < buflen && sg_miter_next(&miter)) {
- unsigned int len;
-
- len = min(miter.length, buflen - offset);
- memset(miter.addr, 0, len);
-
- offset += len;
- }
-
- sg_miter_stop(&miter);
- return offset;
+ return sgl_memset(sgl, nents, skip, 0, buflen);
}
EXPORT_SYMBOL(sg_zero_buffer);
May as well make this one liner a static inline in the header. Just
rename this function to sgl_memset so the diff is clearer
Yes, fine. I can roll a new version.
Doug Gilbert
