Commit e9d9576d authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

kfifo: remove support for physically non-contiguous memory 



First, there is no such user. The only user of this interface is
caam_rng_fill_async() and that uses kfifo_alloc() -> kmalloc().

Second, the implementation does not allow anything else than direct
mapping and kmalloc() (due to virt_to_phys()), anyway.

Therefore, there is no point in having this dead (and complex) code in
the kernel.

Note the setup_sgl_buf() function now boils down to simple sg_set_buf().
That is called twice from setup_sgl() to take care of kfifo buffer
wrap-around.

setup_sgl_buf() will be extended shortly, so keeping it in place.

Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Stefani Seibold <stefani@seibold.net>
Link: https://lore.kernel.org/r/20240405060826.2521-5-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4edd7e96

lib/kfifo.c

+5 −33
Original line number Diff line number Diff line
@@ -305,43 +305,15 @@ int __kfifo_to_user(struct __kfifo *fifo, void __user *to, 
}

EXPORT_SYMBOL(__kfifo_to_user);



static int setup_sgl_buf(struct scatterlist *sgl, void *buf,

static unsigned int setup_sgl_buf(struct scatterlist *sgl, void *buf,

				  int nents, unsigned int len)

{

	int n;

	unsigned int l;

	unsigned int off;

	struct page *page;



	if (!nents)

	if (!nents || !len)

		return 0;



	if (!len)

		return 0;

	sg_set_buf(sgl, buf, len);



	n = 0;

	page = virt_to_page(buf);

	off = offset_in_page(buf);

	l = 0;



	while (len >= l + PAGE_SIZE - off) {

		struct page *npage;



		l += PAGE_SIZE;

		buf += PAGE_SIZE;

		npage = virt_to_page(buf);

		if (page_to_phys(page) != page_to_phys(npage) - l) {

			sg_set_page(sgl, page, l - off, off);

			sgl = sg_next(sgl);

			if (++n == nents || sgl == NULL)

				return n;

			page = npage;

			len -= l - off;

			l = off = 0;

		}

	}

	sg_set_page(sgl, page, len, off);

	return n + 1;

	return 1;

}



static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,