From 8214a65ad1f4ccd4966e0def0d43f0c4289e4bc6 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Thu, 27 Aug 2009 18:32:07 -0700
Subject: [PATCH] Add drm_intel_bo_busy to query whether mapping a BO would block.

---
 libdrm/intel/intel_bufmgr.c      |    7 +++++++
 libdrm/intel/intel_bufmgr.h      |    1 +
 libdrm/intel/intel_bufmgr_gem.c  |   28 +++++++++++++++++++---------
 libdrm/intel/intel_bufmgr_priv.h |    8 +++++++-
 4 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/libdrm/intel/intel_bufmgr.c b/libdrm/intel/intel_bufmgr.c
index f170e7f..219c761 100644
--- a/libdrm/intel/intel_bufmgr.c
+++ b/libdrm/intel/intel_bufmgr.c
@@ -220,6 +220,13 @@ int drm_intel_bo_disable_reuse(drm_intel_bo *bo)
 	return 0;
 }
 
+int drm_intel_bo_busy(drm_intel_bo *bo)
+{
+	if (bo->bufmgr->bo_busy)
+		return bo->bufmgr->bo_busy(bo);
+	return 0;
+}
+
 int
 drm_intel_get_pipe_from_crtc_id (drm_intel_bufmgr *bufmgr, int crtc_id)
 {
diff --git a/libdrm/intel/intel_bufmgr.h b/libdrm/intel/intel_bufmgr.h
index 758558d..218b759 100644
--- a/libdrm/intel/intel_bufmgr.h
+++ b/libdrm/intel/intel_bufmgr.h
@@ -107,6 +107,7 @@ int drm_intel_bo_set_tiling(drm_intel_bo *bo, uint32_t *tiling_mode,
 int drm_intel_bo_get_tiling(drm_intel_bo *bo, uint32_t *tiling_mode,
 			uint32_t *swizzle_mode);
 int drm_intel_bo_flink(drm_intel_bo *bo, uint32_t *name);
+int drm_intel_bo_busy(drm_intel_bo *bo);
 
 int drm_intel_bo_disable_reuse(drm_intel_bo *bo);
 
diff --git a/libdrm/intel/intel_bufmgr_gem.c b/libdrm/intel/intel_bufmgr_gem.c
index 737ceae..baa0ee6 100644
--- a/libdrm/intel/intel_bufmgr_gem.c
+++ b/libdrm/intel/intel_bufmgr_gem.c
@@ -314,6 +314,22 @@ drm_intel_setup_reloc_list(drm_intel_bo *bo)
     return 0;
 }
 
+static int
+drm_intel_gem_bo_busy(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;
+    struct drm_i915_gem_busy busy;
+    int ret;
+
+    memset(&busy, 0, sizeof(busy));
+    busy.handle = bo_gem->gem_handle;
+
+    ret = ioctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_BUSY, &busy);
+
+    return (ret == 0 && busy.busy);
+}
+
 static drm_intel_bo *
 drm_intel_gem_bo_alloc_internal(drm_intel_bufmgr *bufmgr, const char *name,
 				unsigned long size, unsigned int alignment,
@@ -344,8 +360,6 @@ drm_intel_gem_bo_alloc_internal(drm_intel_bufmgr *bufmgr, const char *name,
     pthread_mutex_lock(&bufmgr_gem->lock);
     /* Get a buffer out of the cache if available */
     if (bucket != NULL && bucket->num_entries > 0) {
-	struct drm_i915_gem_busy busy;
-
 	if (for_render) {
 	    /* Allocate new render-target BOs from the tail (MRU)
 	     * of the list, as it will likely be hot in the GPU cache
@@ -364,13 +378,8 @@ drm_intel_gem_bo_alloc_internal(drm_intel_bufmgr *bufmgr, const char *name,
 	     */
 	    bo_gem = DRMLISTENTRY(drm_intel_bo_gem, bucket->head.next, head);
 
-	    memset(&busy, 0, sizeof(busy));
-	    busy.handle = bo_gem->gem_handle;
-
-	    ret = ioctl(bufmgr_gem->fd, DRM_IOCTL_I915_GEM_BUSY, &busy);
-	    alloc_from_cache = (ret == 0 && busy.busy == 0);
-
-	    if (alloc_from_cache) {
+	    if (!drm_intel_gem_bo_busy(&bo_gem->bo)) {
+		alloc_from_cache = 1;
 		DRMLISTDEL(&bo_gem->head);
 		bucket->num_entries--;
 	    }
@@ -1491,6 +1500,7 @@ drm_intel_bufmgr_gem_init(int fd, int batch_size)
     bufmgr_gem->bufmgr.bo_set_tiling = drm_intel_gem_bo_set_tiling;
     bufmgr_gem->bufmgr.bo_flink = drm_intel_gem_bo_flink;
     bufmgr_gem->bufmgr.bo_exec = drm_intel_gem_bo_exec;
+    bufmgr_gem->bufmgr.bo_busy = drm_intel_gem_bo_busy;
     bufmgr_gem->bufmgr.destroy = drm_intel_bufmgr_gem_destroy;
     bufmgr_gem->bufmgr.debug = 0;
     bufmgr_gem->bufmgr.check_aperture_space = drm_intel_gem_check_aperture_space;
diff --git a/libdrm/intel/intel_bufmgr_priv.h b/libdrm/intel/intel_bufmgr_priv.h
index 0098076..af17c12 100644
--- a/libdrm/intel/intel_bufmgr_priv.h
+++ b/libdrm/intel/intel_bufmgr_priv.h
@@ -177,6 +177,12 @@ struct _drm_intel_bufmgr {
      */
     int (*bo_flink)(drm_intel_bo *bo, uint32_t *name);
 
+    /**
+     * Returns 1 if mapping the buffer for write could cause the process
+     * to block, due to the object being active in the GPU.
+     */
+    int (*bo_busy)(drm_intel_bo *bo);
+
     int (*check_aperture_space)(drm_intel_bo **bo_array, int count);
 
     /**
@@ -200,7 +206,7 @@ struct _drm_intel_bufmgr {
      * \param crtc_id the crtc identifier
      */
     int (*get_pipe_from_crtc_id)(drm_intel_bufmgr *bufmgr, int crtc_id);
-    
+
     int debug; /**< Enables verbose debugging printouts */
 };
 
-- 
1.6.4