Hi Andi,
On 2025-01-10 at 11:01:55 +0100, Andi Shyti wrote:
> kmap_local_page(), unlike kmap(), performs a contextualized
> mapping of pages. This means the pages are mapped locally to the
> thread that created them, making them invisible outside the
> thread and safer to use.
>
> Replace kmap() and kunmap() with kmap_local_page() and
> kunmap_local() counterparts for improved safety.
>
> Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/shmem_utils.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c
> index bb696b29ee2c..365c4b8b04f4 100644
> --- a/drivers/gpu/drm/i915/gt/shmem_utils.c
> +++ b/drivers/gpu/drm/i915/gt/shmem_utils.c
> @@ -108,7 +108,7 @@ static int __shmem_rw(struct file *file, loff_t off,
> if (IS_ERR(page))
> return PTR_ERR(page);
>
> - vaddr = kmap(page);
> + vaddr = kmap_local_page(page);
> if (write) {
> memcpy(vaddr + offset_in_page(off), ptr, this);
> set_page_dirty(page);
> @@ -116,7 +116,7 @@ static int __shmem_rw(struct file *file, loff_t off,
> memcpy(ptr, vaddr + offset_in_page(off), this);
> }
> mark_page_accessed(page);
> - kunmap(page);
> + kunmap_local(vaddr);
> put_page(page);
>
> len -= this;
> @@ -143,11 +143,11 @@ int shmem_read_to_iosys_map(struct file *file, loff_t off,
> if (IS_ERR(page))
> return PTR_ERR(page);
>
> - vaddr = kmap(page);
> + vaddr = kmap_local_page(page);
> iosys_map_memcpy_to(map, map_off, vaddr + offset_in_page(off),
> this);
> mark_page_accessed(page);
> - kunmap(page);
> + kunmap_local(vaddr);
> put_page(page);
>
> len -= this;
> --
Reviewed-by: Krzysztof Karas <krzysztof.karas@xxxxxxxxx>
Krzysztof
>
