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: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Stefani Seibold <stefani@xxxxxxxxxxx>
---
lib/kfifo.c | 38 +++++---------------------------------
1 file changed, 5 insertions(+), 33 deletions(-)
diff --git a/lib/kfifo.c b/lib/kfifo.c
index a36bfdbdb17d..d5830960ab87 100644
--- a/lib/kfifo.c
+++ b/lib/kfifo.c
@@ -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,
- int nents, unsigned int len)
+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,
--
2.44.0
