From 6a2c4232ece145d8b5a8f95f767bd6d0d2d2f2bb Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 4 Nov 2014 04:51:40 -0800 Subject: drm/i915: Make the physical object coherent with GTT MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently objects for which the hardware needs a contiguous physical address are allocated a shadow backing storage to satisfy the contraint. This shadow buffer is not wired into the normal obj->pages and so the physical object is incoherent with accesses via the GPU, GTT and CPU. By setting up the appropriate scatter-gather table, we can allow userspace to access the physical object via either a GTT mmaping of or by rendering into the GEM bo. However, keeping the CPU mmap of the shmemfs backing storage coherent with the contiguous shadow is not yet possible. Fortuituously, CPU mmaps of objects requiring physical addresses are not expected to be coherent anyway. This allows the physical constraint of the GEM object to be transparent to userspace and allow it to efficiently render into or update them via the GTT and GPU. v2: Fix leak of pci handle spotted by Ville v3: Remove the now duplicate call to detach_phys_object during free. v4: Wait for rendering before pwrite. As this patch makes it possible to render into the phys object, we should make it correct as well! Signed-off-by: Chris Wilson Cc: Ville Syrjälä Reviewed-by: Ville Syrjälä Signed-off-by: Rodrigo Vivi Signed-off-by: Daniel Vetter --- include/uapi/drm/i915_drm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index 2ec0efcaa719..250262265ee3 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -340,6 +340,7 @@ typedef struct drm_i915_irq_wait { #define I915_PARAM_HAS_EXEC_HANDLE_LUT 26 #define I915_PARAM_HAS_WT 27 #define I915_PARAM_CMD_PARSER_VERSION 28 +#define I915_PARAM_HAS_COHERENT_PHYS_GTT 29 typedef struct drm_i915_getparam { int param; -- cgit v1.2.3