On Thu, Mar 03, 2022 at 11:30:08PM +0530, Balasubramani Vivekanandan wrote:
Fast copy using non-temporal instructions for x86 currently exists at two locations. One is implemented in i915 driver at i915/i915_memcpy.c and another copy at drm_cache.c. The plan is to remove the duplicate implementation in i915 driver and use the functions from drm_cache.c. A variant of drm_memcpy_from_wc() is added in drm_cache.c which accepts address as argument instead of iosys_map for destination. It is a very common scenario in i915 to copy from a WC memory type, which may be an io memory or a system memory to a destination address pointing to system memory. To avoid the overhead of creating iosys_map type for the destination, new variant is created to accept the address directly. Also a new function is exported in drm_cache.c to find if the fast copy is supported by the platform or not. It is required for i915. Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Thomas Hellstr_m <thomas.hellstrom@xxxxxxxxxxxxxxx> Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@xxxxxxxxx> --- drivers/gpu/drm/drm_cache.c | 54 +++++++++++++++++++++++++++++++++++++ include/drm/drm_cache.h | 3 +++ 2 files changed, 57 insertions(+) diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c index a21c1350eb09..97959eecc300 100644 --- a/drivers/gpu/drm/drm_cache.c +++ b/drivers/gpu/drm/drm_cache.c @@ -358,6 +358,54 @@ void drm_memcpy_from_wc(struct iosys_map *dst, } EXPORT_SYMBOL(drm_memcpy_from_wc); +/** + * drm_memcpy_from_wc_vaddr - Perform the fastest available memcpy from a source + * that may be WC to a destination in system memory. + * @dst: The destination pointer + * @src: The source pointer + * @len: The size of the area to transfer in bytes + * + * Same as drm_memcpy_from_wc except destination is accepted as system memory
drm_memcpy_from_wc() for kernel doc
+ * address. Useful in situations where passing destination address as iosys_map + * is simply an overhead and can be avoided. + */ +void drm_memcpy_from_wc_vaddr(void *dst, const struct iosys_map *src,
As in the first version, still don't like the name, but ok. Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Lucas De Marchi
