Commit 18ce31aa authored Mar 30, 2022 by Fabio M. De Francesco Committed by Greg Kroah-Hartman Apr 04, 2022

staging: rts5208: Convert kmap() to kmap_local_page()



The use of kmap() is being deprecated in favor of kmap_local_page()
where it is feasible.

With kmap_local_page(), the mapping is per thread, CPU local and not
globally visible. Therefore rtsx_stor_access_xfer_buf() is a function
where the use of kmap_local_page() in place of kmap() is correctly
suited.

Convert to kmap_local_page() but, instead of open coding it, use the
helpers memcpy_to_page() and memcpy_from_page().

Make a minor change to a comment related to scatter-gather.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20220330143331.8306-1-fmdefrancesco@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent dbf6851f

drivers/staging/rts5208/rtsx_transport.c

+5 −7

Original line number	Diff line number	Diff line
		@@ -56,8 +56,8 @@ unsigned int rtsx_stor_access_xfer_buf(unsigned char *buffer,

		/*
		* Using scatter-gather. We have to go through the list one entry
		* at a time. Each s-g entry contains some number of pages, and
		* each page has to be kmap()'ed separately.
		* at a time. Each s-g entry contains some number of pages which
		* have to be copied one at a time.
		*/
		} else {
		struct scatterlist *sg =
		@@ -92,13 +92,11 @@ unsigned int rtsx_stor_access_xfer_buf(unsigned char *buffer,
		while (sglen > 0) {
		unsigned int plen = min(sglen, (unsigned int)
		PAGE_SIZE - poff);
		unsigned char *ptr = kmap(page);

		if (dir == TO_XFER_BUF)
		memcpy(ptr + poff, buffer + cnt, plen);
		memcpy_to_page(page, poff, buffer + cnt, plen);
		else
		memcpy(buffer + cnt, ptr + poff, plen);
		kunmap(page);
		memcpy_from_page(buffer + cnt, page, poff, plen);

		/* Start at the beginning of the next page */
		poff = 0;