[Intel-gfx] [PATCH] intel: hack to allow WO mappings

[Ben Widawsky]

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 intel/intel_bufmgr_gem.c |   49 +++++++++++++++++++++++++++++++++++++++------
 1 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 4f4de92..7431ed9 100644
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -195,6 +195,11 @@ struct _drm_intel_bo_gem {
 	 * relocations.
 	 */
 	int reloc_tree_fences;
+
+	/**
+	 * CPU write only buffer.
+	 */
+	char cpu_mapping;
 };
 
 static unsigned int
@@ -998,15 +1003,12 @@ static void drm_intel_gem_bo_unreference(drm_intel_bo *bo)
 	}
 }
 
-static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
+static int do_gem_bo_map(drm_intel_bo *bo, int write_enable)
 {
 	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
 	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
-	struct drm_i915_gem_set_domain set_domain;
 	int ret;
 
-	pthread_mutex_lock(&bufmgr_gem->lock);
-
 	/* Allow recursive mapping. Mesa may recursively map buffers with
 	 * nested display loops.
 	 */
@@ -1018,6 +1020,8 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
 		memset(&mmap_arg, 0, sizeof(mmap_arg));
 		mmap_arg.handle = bo_gem->gem_handle;
 		mmap_arg.offset = 0;
+		if (write_enable == 27)
+			mmap_arg.offset |= 1 ;
 		mmap_arg.size = bo->size;
 		ret = drmIoctl(bufmgr_gem->fd,
 			       DRM_IOCTL_I915_GEM_MMAP,
@@ -1027,7 +1031,6 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
 			DBG("%s:%d: Error mapping buffer %d (%s): %s .\n",
 			    __FILE__, __LINE__, bo_gem->gem_handle,
 			    bo_gem->name, strerror(errno));
-			pthread_mutex_unlock(&bufmgr_gem->lock);
 			return ret;
 		}
 		bo_gem->mem_virtual = (void *)(uintptr_t) mmap_arg.addr_ptr;
@@ -1036,6 +1039,39 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
 	    bo_gem->mem_virtual);
 	bo->virtual = bo_gem->mem_virtual;
 
+	return 0;
+}
+
+static int drm_intel_gem_bo_map_wo(drm_intel_bo *bo)
+{
+	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+	int wo_mapping_change;
+	int ret;
+
+	wo_mapping_change = ((bo_gem->cpu_mapping) != 0);
+	assert(!bo_gem->mem_virtual || !wo_mapping_change);
+
+	pthread_mutex_lock(&bufmgr_gem->lock);
+	ret = do_gem_bo_map(bo, 27);
+	if (ret == 0)
+		bo_gem->cpu_mapping = 1;
+	pthread_mutex_unlock(&bufmgr_gem->lock);
+	return ret;
+}
+
+static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
+{
+	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
+	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
+	struct drm_i915_gem_set_domain set_domain;
+	int ret;
+
+	if (write_enable == 27)
+		return drm_intel_gem_bo_map_wo(bo);
+
+	pthread_mutex_lock(&bufmgr_gem->lock);
+	ret = do_gem_bo_map(bo, write_enable);
 	set_domain.handle = bo_gem->gem_handle;
 	set_domain.read_domains = I915_GEM_DOMAIN_CPU;
 	if (write_enable)
@@ -1052,8 +1088,7 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
 	}
 
 	pthread_mutex_unlock(&bufmgr_gem->lock);
-
-	return 0;
+	return ret;
 }
 
 int drm_intel_gem_bo_map_gtt(drm_intel_bo *bo)
-- 
1.7.6