On 29.08.2014 00:01, Alex Deucher wrote:
On Thu, Aug 28, 2014 at 4:57 AM, Christian König deathsimple@vodafone.de wrote:
Am 28.08.2014 um 08:56 schrieb Michel Dänzer:
From: Michel Dänzer michel.daenzer@amd.com
This flag is a hint that userspace expects the BO to be accessed by the CPU. We can use that hint to prevent such BOs from ever being stored in the CPU inaccessible part of VRAM.
Signed-off-by: Michel Dänzer michel.daenzer@amd.com
This patch is Reviewed-by: Christian König christian.koenig@amd.com
Applied to my -next tree.
Thanks!
I think we need a similar negative flags as well, e.g. RADEON_GEM_NO_CPU_ACCESS.
This way we can stop forcing buffers into the visible VRAM while pinning them for scanout.
How about the attached patch?
[...]
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c index 09b039a..b71e8e0 100644 --- a/drivers/gpu/drm/radeon/radeon_object.c +++ b/drivers/gpu/drm/radeon/radeon_object.c @@ -314,10 +314,14 @@ int radeon_bo_pin_restricted(struct radeon_bo *bo, u32 domain, u64 max_offset, unsigned lpfn = 0;
/* force to pin into visible video ram */
if (bo->placements[i].flags & TTM_PL_FLAG_VRAM)lpfn = bo->rdev->mc.visible_vram_size >> PAGE_SHIFT;else
if (bo->placements[i].flags & TTM_PL_FLAG_VRAM) {if (bo->flags & RADEON_GEM_NO_CPU_ACCESS)lpfn = bo->rdev->mc.real_vram_size >> PAGE_SHIFT;elselpfn = bo->rdev->mc.visible_vram_size >> PAGE_SHIFT;
lpfn can be left at 0 if RADEON_GEM_NO_CPU_ACCESS is set, so this can be simplified to:
if (!(bo->flags & RADEON_GEM_NO_CPU_ACCESS)) lpfn = bo->rdev->mc.visible_vram_size >> PAGE_SHIFT;
diff --git a/include/uapi/drm/radeon_drm.h b/include/uapi/drm/radeon_drm.h index f755f20..d2346fd 100644 --- a/include/uapi/drm/radeon_drm.h +++ b/include/uapi/drm/radeon_drm.h @@ -803,6 +803,8 @@ struct drm_radeon_gem_info { #define RADEON_GEM_GTT_WC (1 << 2) /* BO is expected to be accessed by the CPU */ #define RADEON_GEM_CPU_ACCESS (1 << 3) +/* BO is expected to not be accessed by the CPU */ +#define RADEON_GEM_NO_CPU_ACCESS (1 << 4)
I'd use stronger wording for this, e.g.
/* CPU access is not expected to work for this BO */