diff options
| author | Thomas Hellström <thomas.hellstrom@linux.intel.com> | 2021-06-02 10:38:11 +0200 |
|---|---|---|
| committer | Thomas Hellström <thomas.hellstrom@linux.intel.com> | 2021-06-07 16:07:08 +0200 |
| commit | b7e32bef4ae5f9149276203564b7911fac466588 (patch) | |
| tree | b8752329b4d43041fe4837a322cf684513bd697d /include/drm/drm_cache.h | |
| parent | 3bf3710e3718a5aebdf465343bc1125b6e8cca96 (diff) | |
drm: Add a prefetching memcpy_from_wc
Reading out of write-combining mapped memory is typically very slow
since the CPU doesn't prefetch. However some archs have special
instructions to do this.
So add a best-effort memcpy_from_wc taking dma-buf-map pointer
arguments that attempts to use a fast prefetching memcpy and
otherwise falls back to ordinary memcopies, taking the iomem tagging
into account.
The code is largely copied from i915_memcpy_from_wc.
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Christian König <christian.koenig@amd.com>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://lore.kernel.org/r/20210602083818.241793-5-thomas.hellstrom@linux.intel.com
Link: https://patchwork.freedesktop.org/patch/msgid/20210602083818.241793-5-thomas.hellstrom@linux.intel.com
Diffstat (limited to 'include/drm/drm_cache.h')
| -rw-r--r-- | include/drm/drm_cache.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/drm/drm_cache.h b/include/drm/drm_cache.h index e9ad4863d915..cc9de1632dd3 100644 --- a/include/drm/drm_cache.h +++ b/include/drm/drm_cache.h @@ -35,6 +35,8 @@ #include <linux/scatterlist.h> +struct dma_buf_map; + void drm_clflush_pages(struct page *pages[], unsigned long num_pages); void drm_clflush_sg(struct sg_table *st); void drm_clflush_virt_range(void *addr, unsigned long length); @@ -70,4 +72,9 @@ static inline bool drm_arch_can_wc_memory(void) #endif } +void drm_memcpy_init_early(void); + +void drm_memcpy_from_wc(struct dma_buf_map *dst, + const struct dma_buf_map *src, + unsigned long len); #endif |