From a3c435b342e467020e349061ce656c68258a8576 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Sun, 16 Dec 2007 22:25:33 -0800
Subject: [PATCH] Set correct flags mask when validating buffers.

The 'mask' value used in the validation operation specifies which of the
'flags' bits are being modified. Buffer validation wants to pass the memory
type and access mode (rwx) to the kernel so that the buffer will be placed
correctly, and so that the right kind of fence will be created (read vs
write). That means we actually want a constant mask for these operations,
and not something computed from the bits coming in. The constant we want is
DRM_BO_MASK_MEM | DRM_BO_FLAG_READ | DRM_BO_FLAG_WRITE | DRM_BO_FLAG_EXE.
---
 src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c | 44 +++++++++----------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c b/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
index b2aa056b906..b9eabb42c01 100644
--- a/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
+++ b/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
@@ -53,6 +53,17 @@
       _mesa_printf(__VA_ARGS__);			\
 } while (0)
 
+/*
+ * These bits are always specified in each validation
+ * request. Other bits are not supported at this point
+ * as it would require a bit of investigation to figure
+ * out what mask value should be used.
+ */
+#define INTEL_BO_MASK  (DRM_BO_MASK_MEM | \
+			DRM_BO_FLAG_READ | \
+			DRM_BO_FLAG_WRITE | \
+			DRM_BO_FLAG_EXE)
+
 /* Buffer validation list */
 struct intel_bo_list {
     unsigned numCurrent;
@@ -98,7 +109,6 @@ struct intel_bo_node
     dri_bo *bo;
     struct drm_i915_op_arg bo_arg;
     uint64_t flags;
-    uint64_t mask;
 };
 
 static void
@@ -197,7 +207,7 @@ intel_setup_validate_list(dri_bufmgr_ttm *bufmgr_ttm, GLuint *count_p)
 	req->bo_req.hint |= DRM_BO_HINT_PRESUMED_OFFSET;
 	req->bo_req.presumed_offset = node->bo->offset;
 #endif
-	req->bo_req.mask = node->mask;
+	req->bo_req.mask = INTEL_BO_MASK;
 	req->bo_req.fence_class = 0; /* Backwards compat. */
 
 	if (ttm_buf->reloc_buf != NULL)
@@ -221,12 +231,12 @@ intel_setup_validate_list(dri_bufmgr_ttm *bufmgr_ttm, GLuint *count_p)
  *
  * If a buffer is validated multiple times in a batch submission, it ends up
  * with the intersection of the memory type flags and the union of the
- * remaining flags.
+ * access flags.
  */
 static struct intel_bo_node *
 intel_add_validate_buffer(dri_bufmgr_ttm *bufmgr_ttm,
 			  dri_bo *buf,
-			  uint64_t flags, uint64_t mask,
+			  uint64_t flags,
 			  int *itemLoc)
 {
     struct intel_bo_list *list = &bufmgr_ttm->list;
@@ -257,31 +267,27 @@ intel_add_validate_buffer(dri_bufmgr_ttm *bufmgr_ttm,
 	cur->bo = buf;
 	dri_bo_reference(buf);
 	cur->flags = flags;
-	cur->mask = mask;
 	ret = 1;
 
 	DRMLISTADDTAIL(&cur->head, &list->list);
     } else {
-	uint64_t memMask = (cur->mask | mask) & DRM_BO_MASK_MEM;
-	uint64_t memFlags = cur->flags & flags & memMask;
+	uint64_t memFlags = cur->flags & flags & DRM_BO_MASK_MEM;
+	uint64_t modeFlags = (cur->flags | flags) & ~DRM_BO_MASK_MEM;
 
-	if (!memFlags) {
+	if (memFlags == 0) {
 	    fprintf(stderr,
 		    "%s: No shared memory types between "
 		    "0x%16llx and 0x%16llx\n",
 		    __FUNCTION__, cur->flags, flags);
 	    return NULL;
 	}
-	if (mask & cur->mask & ~DRM_BO_MASK_MEM  & (cur->flags ^ flags)) {
+	if (flags & ~INTEL_BO_MASK) {
 	    fprintf(stderr,
-		    "%s: Incompatible flags between 0x%16llx and 0x%16llx "
-		    "(0x%16llx, 0x%16llx masks)\n",
-		    __FUNCTION__, cur->flags, flags, cur->mask, mask);
+		    "%s: Flags bits 0x%16llx are not supposed to be used in a relocation\n",
+		    __FUNCTION__, flags & ~INTEL_BO_MASK);
 	    return NULL;
 	}
-	cur->mask |= mask;
-	cur->flags = memFlags | ((cur->flags | flags) &
-				cur->mask & ~DRM_BO_MASK_MEM);
+	cur->flags = memFlags | modeFlags;
     }
     *itemLoc = count;
 
@@ -649,15 +655,10 @@ dri_ttm_emit_reloc(dri_bo *reloc_buf, uint64_t flags, GLuint delta,
     dri_bo_ttm *reloc_buf_ttm = (dri_bo_ttm *)reloc_buf;
     struct intel_bo_node *node;
     int index;
-    int mask;
     int num_relocs;
     uint32_t *this_reloc;
 
-    mask = DRM_BO_MASK_MEM;
-    mask |= flags & (DRM_BO_FLAG_READ | DRM_BO_FLAG_WRITE | DRM_BO_FLAG_EXE);
-
-    node = intel_add_validate_buffer(bufmgr_ttm, target_buf, flags, mask,
-				     &index);
+    node = intel_add_validate_buffer(bufmgr_ttm, target_buf, flags, &index);
 
     intel_setup_reloc_list(reloc_buf);
 
@@ -692,7 +693,6 @@ dri_ttm_process_reloc(dri_bo *batch_buf, GLuint *count)
      */
     intel_add_validate_buffer(bufmgr_ttm, batch_buf,
 			      DRM_BO_FLAG_MEM_TT | DRM_BO_FLAG_EXE,
-			      DRM_BO_MASK_MEM | DRM_BO_FLAG_EXE,
 			      &index);
 
     ptr = intel_setup_validate_list(bufmgr_ttm, count);
-- 
2.30.2