lkml.org 
[lkml]   [2021]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v5 4/4] scatterlist: add sgl_memset()
From
Date
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@gmail.com>
>> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
>> 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


\
 
 \ /
  Last update: 2021-01-10 00:02    [W:0.269 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site