pipebuffer: Implement proper buffer validation.

14 files changed, 367 insertions, 108 deletions

diff --git a/src/gallium/auxiliary/pipebuffer/pb_buffer.h b/src/gallium/auxiliary/pipebuffer/pb_buffer.h
index 8505d333bd..c9570d7be2 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_buffer.h
+++ b/src/gallium/auxiliary/pipebuffer/pb_buffer.h
@@ -37,7 +37,7 @@
  * There is no obligation of a winsys driver to use this library. And a pipe
  * driver should be completly agnostic about it.
  * 
- * \author Jos� Fonseca <jrfonseca@tungstengraphics.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.com>
  */
 
 #ifndef PB_BUFFER_H_
@@ -46,6 +46,7 @@
 
 #include "pipe/p_compiler.h"
 #include "pipe/p_debug.h"
+#include "pipe/p_error.h"
 #include "pipe/p_state.h"
 #include "pipe/p_inlines.h"
 
@@ -56,6 +57,8 @@ extern "C" {
 
 
 struct pb_vtbl;
+struct pb_validate;
+
 
 /**
  * Buffer description.
@@ -104,6 +107,13 @@ struct pb_vtbl
    
    void (*unmap)( struct pb_buffer *buf );
 
+   enum pipe_error (*validate)( struct pb_buffer *buf, 
+                                struct pb_validate *vl,
+                                unsigned flags );
+
+   void (*fence)( struct pb_buffer *buf, 
+                  struct pipe_fence_handle *fence );
+
    /**
     * Get the base buffer and the offset.
     * 
@@ -118,6 +128,7 @@ struct pb_vtbl
    void (*get_base_buffer)( struct pb_buffer *buf,
                             struct pb_buffer **base_buf,
                             unsigned *offset );
+   
 };
 
 
@@ -173,10 +184,33 @@ pb_get_base_buffer( struct pb_buffer *buf,
       offset = 0;
       return;
    }
+   assert(buf->vtbl->get_base_buffer);
    buf->vtbl->get_base_buffer(buf, base_buf, offset);
 }
 
 
+static INLINE enum pipe_error 
+pb_validate(struct pb_buffer *buf, struct pb_validate *vl, unsigned flags)
+{
+   assert(buf);
+   if(!buf)
+      return PIPE_ERROR;
+   assert(buf->vtbl->validate);
+   return buf->vtbl->validate(buf, vl, flags);
+}
+
+
+static INLINE void 
+pb_fence(struct pb_buffer *buf, struct pipe_fence_handle *fence)
+{
+   assert(buf);
+   if(!buf)
+      return;
+   assert(buf->vtbl->fence);
+   buf->vtbl->fence(buf, fence);
+}
+
+
 static INLINE void 
 pb_destroy(struct pb_buffer *buf)
 {
diff --git a/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.c b/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.c
index 17b2781052..17300cb553 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.c
@@ -29,7 +29,7 @@
  * \file
  * Implementation of fenced buffers.
  * 
- * \author José Fonseca <jrfonseca-at-tungstengraphics-dot-com>
+ * \author Jose Fonseca <jrfonseca-at-tungstengraphics-dot-com>
  * \author Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
@@ -59,13 +59,6 @@
  */
 #define SUPER(__derived) (&(__derived)->base)
 
-#define PIPE_BUFFER_USAGE_CPU_READ_WRITE \
-   ( PIPE_BUFFER_USAGE_CPU_READ | PIPE_BUFFER_USAGE_CPU_WRITE )
-#define PIPE_BUFFER_USAGE_GPU_READ_WRITE \
-   ( PIPE_BUFFER_USAGE_GPU_READ | PIPE_BUFFER_USAGE_GPU_WRITE )
-#define PIPE_BUFFER_USAGE_WRITE \
-   ( PIPE_BUFFER_USAGE_CPU_WRITE | PIPE_BUFFER_USAGE_GPU_WRITE )
-
 
 struct fenced_buffer_list
 {
@@ -97,6 +90,8 @@ struct fenced_buffer
    unsigned flags;
 
    unsigned mapcount;
+   struct pb_validate *vl;
+   unsigned validation_flags;
    struct pipe_fence_handle *fence;
 
    struct list_head head;
@@ -108,7 +103,6 @@ static INLINE struct fenced_buffer *
 fenced_buffer(struct pb_buffer *buf)
 {
    assert(buf);
-   assert(buf->vtbl == &fenced_buffer_vtbl);
    return (struct fenced_buffer *)buf;
 }
 
@@ -274,6 +268,7 @@ fenced_buffer_map(struct pb_buffer *buf,
    struct fenced_buffer *fenced_buf = fenced_buffer(buf);
    void *map;
 
+   assert(flags & PIPE_BUFFER_USAGE_CPU_READ_WRITE);
    assert(!(flags & ~PIPE_BUFFER_USAGE_CPU_READ_WRITE));
    flags &= PIPE_BUFFER_USAGE_CPU_READ_WRITE;
    
@@ -315,6 +310,101 @@ fenced_buffer_unmap(struct pb_buffer *buf)
 }
 
 
+static enum pipe_error
+fenced_buffer_validate(struct pb_buffer *buf,
+                       struct pb_validate *vl,
+                       unsigned flags)
+{
+   struct fenced_buffer *fenced_buf = fenced_buffer(buf);
+   enum pipe_error ret;
+   
+   if(!vl) {
+      /* invalidate */
+      fenced_buf->vl = NULL;
+      fenced_buf->validation_flags = 0;
+      return PIPE_OK;
+   }
+   
+   assert(flags & PIPE_BUFFER_USAGE_GPU_READ_WRITE);
+   assert(!(flags & ~PIPE_BUFFER_USAGE_GPU_READ_WRITE));
+   flags &= PIPE_BUFFER_USAGE_GPU_READ_WRITE;
+
+   /* Buffer cannot be validated in two different lists */ 
+   if(fenced_buf->vl && fenced_buf->vl != vl)
+      return PIPE_ERROR_RETRY;
+   
+   /* Do not validate if buffer is still mapped */
+   if(fenced_buf->flags & PIPE_BUFFER_USAGE_CPU_READ_WRITE) {
+      /* TODO: wait for the thread that mapped the buffer to unmap it */
+      return PIPE_ERROR_RETRY;
+   }
+
+   /* Allow concurrent GPU reads, but serialize GPU writes */
+   if(fenced_buf->flags & PIPE_BUFFER_USAGE_GPU_READ_WRITE) {
+      if((fenced_buf->flags | flags) & PIPE_BUFFER_USAGE_GPU_WRITE) {
+         _fenced_buffer_finish(fenced_buf);
+      }
+   }
+
+   if(fenced_buf->vl == vl &&
+      (fenced_buf->validation_flags & flags) == flags) {
+      /* Nothing to do -- buffer already validated */
+      return PIPE_OK;
+   }
+
+   /* Final sanity checking */
+   assert(!(fenced_buf->flags & PIPE_BUFFER_USAGE_CPU_READ_WRITE));
+   assert(!(fenced_buf->flags & PIPE_BUFFER_USAGE_GPU_WRITE));
+   assert(!fenced_buf->mapcount);
+   
+   ret = pb_validate(fenced_buf->buffer, vl, flags);
+   if (ret != PIPE_OK)
+      return ret;
+   
+   fenced_buf->vl = vl;
+   fenced_buf->validation_flags |= flags;
+   
+   return PIPE_OK;
+}
+
+
+static void
+fenced_buffer_fence(struct pb_buffer *buf,
+                    struct pipe_fence_handle *fence)
+{
+   struct fenced_buffer *fenced_buf;
+   struct fenced_buffer_list *fenced_list;
+   struct pipe_winsys *winsys;
+
+   fenced_buf = fenced_buffer(buf);
+   fenced_list = fenced_buf->list;
+   winsys = fenced_list->winsys;
+   
+   if(fence == fenced_buf->fence) {
+      /* Nothing to do */
+      return;
+   }
+
+   assert(fenced_buf->vl);
+   assert(fenced_buf->validation_flags);
+   
+   pipe_mutex_lock(fenced_list->mutex);
+   if (fenced_buf->fence)
+      _fenced_buffer_remove(fenced_list, fenced_buf);
+   if (fence) {
+      winsys->fence_reference(winsys, &fenced_buf->fence, fence);
+      fenced_buf->flags |= fenced_buf->validation_flags;
+      _fenced_buffer_add(fenced_buf);
+   }
+   pipe_mutex_unlock(fenced_list->mutex);
+   
+   pb_fence(fenced_buf->buffer, fence);
+
+   fenced_buf->vl = NULL;
+   fenced_buf->validation_flags = 0;
+}
+
+
 static void
 fenced_buffer_get_base_buffer(struct pb_buffer *buf,
                               struct pb_buffer **base_buf,
@@ -325,11 +415,13 @@ fenced_buffer_get_base_buffer(struct pb_buffer *buf,
 }
 
 
-const struct pb_vtbl 
+static const struct pb_vtbl 
 fenced_buffer_vtbl = {
       fenced_buffer_destroy,
       fenced_buffer_map,
       fenced_buffer_unmap,
+      fenced_buffer_validate,
+      fenced_buffer_fence,
       fenced_buffer_get_base_buffer
 };
 
@@ -362,52 +454,6 @@ fenced_buffer_create(struct fenced_buffer_list *fenced_list,
 }
 
 
-void
-buffer_fence(struct pb_buffer *buf,
-             struct pipe_fence_handle *fence)
-{
-   struct fenced_buffer *fenced_buf;
-   struct fenced_buffer_list *fenced_list;
-   struct pipe_winsys *winsys;
-   /* FIXME: receive this as a parameter */
-   unsigned flags = fence ? PIPE_BUFFER_USAGE_GPU_READ_WRITE : 0;
-
-   /* This is a public function, so be extra cautious with the buffer passed, 
-    * as happens frequently to receive null buffers, or pointer to buffers 
-    * other than fenced buffers. */
-   assert(buf);
-   if(!buf)
-      return;
-   assert(buf->vtbl == &fenced_buffer_vtbl);
-   if(buf->vtbl != &fenced_buffer_vtbl)
-      return;
-   
-   fenced_buf = fenced_buffer(buf);
-   fenced_list = fenced_buf->list;
-   winsys = fenced_list->winsys;
-   
-   if(!fence || fence == fenced_buf->fence) {
-      /* Handle the same fence case specially, not only because it is a fast 
-       * path, but mostly to avoid serializing two writes with the same fence, 
-       * as that would bring the hardware down to synchronous operation without
-       * any benefit.
-       */
-      fenced_buf->flags |= flags & PIPE_BUFFER_USAGE_GPU_READ_WRITE;
-      return;
-   }
-   
-   pipe_mutex_lock(fenced_list->mutex);
-   if (fenced_buf->fence)
-      _fenced_buffer_remove(fenced_list, fenced_buf);
-   if (fence) {
-      winsys->fence_reference(winsys, &fenced_buf->fence, fence);
-      fenced_buf->flags |= flags & PIPE_BUFFER_USAGE_GPU_READ_WRITE;
-      _fenced_buffer_add(fenced_buf);
-   }
-   pipe_mutex_unlock(fenced_list->mutex);
-}
-
-
 struct fenced_buffer_list *
 fenced_buffer_list_create(struct pipe_winsys *winsys) 
 {
diff --git a/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.h b/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.h
index 50d5891bdb..b15c676194 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.h
+++ b/src/gallium/auxiliary/pipebuffer/pb_buffer_fenced.h
@@ -44,7 +44,7 @@
  * Between the handle's destruction, and the fence signalling, the buffer is 
  * stored in a fenced buffer list.
  * 
- * \author José Fonseca <jrfonseca@tungstengraphics.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.com>
  */
 
 #ifndef PB_BUFFER_FENCED_H_
@@ -71,14 +71,6 @@ struct fenced_buffer_list;
 
 
 /**
- * The fenced buffer's virtual function table.
- * 
- * NOTE: Made public for debugging purposes.
- */
-extern const struct pb_vtbl fenced_buffer_vtbl;
-
-
-/**
  * Create a fenced buffer list.
  * 
  * See also fenced_bufmgr_create for a more convenient way to use this.
@@ -108,17 +100,6 @@ fenced_buffer_create(struct fenced_buffer_list *fenced,
                      struct pb_buffer *buffer);
 
 
-/**
- * Set a buffer's fence.
- * 
- * NOTE: Although it takes a generic pb_buffer argument, it will fail
- * on everything but buffers returned by fenced_buffer_create.
- */
-void
-buffer_fence(struct pb_buffer *buf,
-             struct pipe_fence_handle *fence);
-
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/gallium/auxiliary/pipebuffer/pb_buffer_malloc.c b/src/gallium/auxiliary/pipebuffer/pb_buffer_malloc.c
index 1bf22a2ec0..53f497cfb0 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_buffer_malloc.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_buffer_malloc.c
@@ -81,6 +81,24 @@ malloc_buffer_unmap(struct pb_buffer *buf)
 }
 
 
+static enum pipe_error 
+malloc_buffer_validate(struct pb_buffer *buf, 
+                       struct pb_validate *vl,
+                       unsigned flags)
+{
+   assert(0);
+   return PIPE_ERROR;
+}
+
+
+static void
+malloc_buffer_fence(struct pb_buffer *buf, 
+                    struct pipe_fence_handle *fence)
+{
+   assert(0);
+}
+
+
 static void
 malloc_buffer_get_base_buffer(struct pb_buffer *buf,
                               struct pb_buffer **base_buf,
@@ -96,6 +114,8 @@ malloc_buffer_vtbl = {
       malloc_buffer_destroy,
       malloc_buffer_map,
       malloc_buffer_unmap,
+      malloc_buffer_validate,
+      malloc_buffer_fence,
       malloc_buffer_get_base_buffer
 };
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr.h b/src/gallium/auxiliary/pipebuffer/pb_bufmgr.h
index cafbee045a..8fe2704708 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr.h
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr.h
@@ -43,7 +43,7 @@
  * - the fenced buffer manager, which will delay buffer destruction until the 
  * the moment the card finishing processing it. 
  * 
- * \author José Fonseca <jrfonseca@tungstengraphics.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.com>
  */
 
 #ifndef PB_BUFMGR_H_
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_cache.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_cache.c
index 8f118874ec..f57a7bffd7 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_cache.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_cache.c
@@ -29,7 +29,7 @@
  * \file
  * Buffer cache.
  * 
- * \author José Fonseca <jrfonseca-at-tungstengraphics-dot-com>
+ * \author Jose Fonseca <jrfonseca-at-tungstengraphics-dot-com>
  * \author Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
@@ -183,6 +183,25 @@ pb_cache_buffer_unmap(struct pb_buffer *_buf)
 }
 
 
+static enum pipe_error 
+pb_cache_buffer_validate(struct pb_buffer *_buf, 
+                         struct pb_validate *vl,
+                         unsigned flags)
+{
+   struct pb_cache_buffer *buf = pb_cache_buffer(_buf);
+   return pb_validate(buf->buffer, vl, flags);
+}
+
+
+static void
+pb_cache_buffer_fence(struct pb_buffer *_buf, 
+                      struct pipe_fence_handle *fence)
+{
+   struct pb_cache_buffer *buf = pb_cache_buffer(_buf);
+   pb_fence(buf->buffer, fence);
+}
+
+
 static void
 pb_cache_buffer_get_base_buffer(struct pb_buffer *_buf,
                               struct pb_buffer **base_buf,
@@ -198,6 +217,8 @@ pb_cache_buffer_vtbl = {
       pb_cache_buffer_destroy,
       pb_cache_buffer_map,
       pb_cache_buffer_unmap,
+      pb_cache_buffer_validate,
+      pb_cache_buffer_fence,
       pb_cache_buffer_get_base_buffer
 };
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_debug.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_debug.c
index 1675e6e182..62639fe1c8 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_debug.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_debug.c
@@ -29,7 +29,7 @@
  * \file
  * Debug buffer manager to detect buffer under- and overflows.
  * 
- * \author José Fonseca <jrfonseca@tungstengraphics.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.com>
  */
 
 
@@ -255,11 +255,35 @@ pb_debug_buffer_get_base_buffer(struct pb_buffer *_buf,
 }
 
 
+static enum pipe_error 
+pb_debug_buffer_validate(struct pb_buffer *_buf, 
+                         struct pb_validate *vl,
+                         unsigned flags)
+{
+   struct pb_debug_buffer *buf = pb_debug_buffer(_buf);
+   
+   pb_debug_buffer_check(buf);
+
+   return pb_validate(buf->buffer, vl, flags);
+}
+
+
+static void
+pb_debug_buffer_fence(struct pb_buffer *_buf, 
+                      struct pipe_fence_handle *fence)
+{
+   struct pb_debug_buffer *buf = pb_debug_buffer(_buf);
+   pb_fence(buf->buffer, fence);
+}
+
+
 const struct pb_vtbl 
 pb_debug_buffer_vtbl = {
       pb_debug_buffer_destroy,
       pb_debug_buffer_map,
       pb_debug_buffer_unmap,
+      pb_debug_buffer_validate,
+      pb_debug_buffer_fence,
       pb_debug_buffer_get_base_buffer
 };
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_fenced.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_fenced.c
index 633ee70a75..f8fd2cd531 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_fenced.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_fenced.c
@@ -30,7 +30,7 @@
  * \file
  * A buffer manager that wraps buffers in fenced buffers.
  * 
- * \author José Fonseca <jrfonseca@tungstengraphics.dot.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.dot.com>
  */
 
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_mm.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_mm.c
index fe80ca30ee..607f10bc73 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_mm.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_mm.c
@@ -29,7 +29,7 @@
  * \file
  * Buffer manager using the old texture memory manager.
  * 
- * \author José Fonseca <jrfonseca@tungstengraphics.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.com>
  */
 
 
@@ -124,6 +124,27 @@ mm_buffer_unmap(struct pb_buffer *buf)
 }
 
 
+static enum pipe_error 
+mm_buffer_validate(struct pb_buffer *buf, 
+                   struct pb_validate *vl,
+                   unsigned flags)
+{
+   struct mm_buffer *mm_buf = mm_buffer(buf);
+   struct mm_pb_manager *mm = mm_buf->mgr;
+   return pb_validate(mm->buffer, vl, flags);
+}
+
+
+static void
+mm_buffer_fence(struct pb_buffer *buf, 
+                struct pipe_fence_handle *fence)
+{
+   struct mm_buffer *mm_buf = mm_buffer(buf);
+   struct mm_pb_manager *mm = mm_buf->mgr;
+   pb_fence(mm->buffer, fence);
+}
+
+
 static void
 mm_buffer_get_base_buffer(struct pb_buffer *buf,
                           struct pb_buffer **base_buf,
@@ -141,6 +162,8 @@ mm_buffer_vtbl = {
       mm_buffer_destroy,
       mm_buffer_map,
       mm_buffer_unmap,
+      mm_buffer_validate,
+      mm_buffer_fence,
       mm_buffer_get_base_buffer
 };
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_pool.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_pool.c
index 61ac291ed7..a6ff37653e 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_pool.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_pool.c
@@ -30,7 +30,7 @@
  * \file
  * Batch buffer pool management.
  * 
- * \author José Fonseca <jrfonseca-at-tungstengraphics-dot-com>
+ * \author Jose Fonseca <jrfonseca-at-tungstengraphics-dot-com>
  * \author Thomas Hellström <thomas-at-tungstengraphics-dot-com>
  */
 
@@ -138,6 +138,27 @@ pool_buffer_unmap(struct pb_buffer *buf)
 }
 
 
+static enum pipe_error 
+pool_buffer_validate(struct pb_buffer *buf, 
+                     struct pb_validate *vl,
+                     unsigned flags)
+{
+   struct pool_buffer *pool_buf = pool_buffer(buf);
+   struct pool_pb_manager *pool = pool_buf->mgr;
+   return pb_validate(pool->buffer, vl, flags);
+}
+
+
+static void
+pool_buffer_fence(struct pb_buffer *buf, 
+                  struct pipe_fence_handle *fence)
+{
+   struct pool_buffer *pool_buf = pool_buffer(buf);
+   struct pool_pb_manager *pool = pool_buf->mgr;
+   pb_fence(pool->buffer, fence);
+}
+
+
 static void
 pool_buffer_get_base_buffer(struct pb_buffer *buf,
                             struct pb_buffer **base_buf,
@@ -155,6 +176,8 @@ pool_buffer_vtbl = {
       pool_buffer_destroy,
       pool_buffer_map,
       pool_buffer_unmap,
+      pool_buffer_validate,
+      pool_buffer_fence,
       pool_buffer_get_base_buffer
 };
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c
index 2a80154920..9b9fedccb4 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_bufmgr_slab.c
@@ -248,6 +248,25 @@ pb_slab_buffer_unmap(struct pb_buffer *_buf)
 }
 
 
+static enum pipe_error 
+pb_slab_buffer_validate(struct pb_buffer *_buf, 
+                         struct pb_validate *vl,
+                         unsigned flags)
+{
+   struct pb_slab_buffer *buf = pb_slab_buffer(_buf);
+   return pb_validate(buf->slab->bo, vl, flags);
+}
+
+
+static void
+pb_slab_buffer_fence(struct pb_buffer *_buf, 
+                      struct pipe_fence_handle *fence)
+{
+   struct pb_slab_buffer *buf = pb_slab_buffer(_buf);
+   pb_fence(buf->slab->bo, fence);
+}
+
+
 static void
 pb_slab_buffer_get_base_buffer(struct pb_buffer *_buf,
                                struct pb_buffer **base_buf,
@@ -264,6 +283,8 @@ pb_slab_buffer_vtbl = {
       pb_slab_buffer_destroy,
       pb_slab_buffer_map,
       pb_slab_buffer_unmap,
+      pb_slab_buffer_validate,
+      pb_slab_buffer_fence,
       pb_slab_buffer_get_base_buffer
 };
 
diff --git a/src/gallium/auxiliary/pipebuffer/pb_validate.c b/src/gallium/auxiliary/pipebuffer/pb_validate.c
index 1e54fc39d4..726ae1688e 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_validate.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_validate.c
@@ -46,9 +46,16 @@
 #define PB_VALIDATE_INITIAL_SIZE 1 /* 512 */ 
 
 
+struct pb_validate_entry
+{
+   struct pb_buffer *buf;
+   unsigned flags;
+};
+
+
 struct pb_validate
 {
-   struct pb_buffer **buffers;
+   struct pb_validate_entry *entries;
    unsigned used;
    unsigned size;
 };
@@ -56,43 +63,50 @@ struct pb_validate
 
 enum pipe_error
 pb_validate_add_buffer(struct pb_validate *vl,
-                       struct pb_buffer *buf)
+                       struct pb_buffer *buf,
+                       unsigned flags)
 {
    assert(buf);
    if(!buf)
       return PIPE_ERROR;
 
+   assert(flags & PIPE_BUFFER_USAGE_GPU_READ_WRITE);
+   assert(!(flags & ~PIPE_BUFFER_USAGE_GPU_READ_WRITE));
+   flags &= PIPE_BUFFER_USAGE_GPU_READ_WRITE;
+
    /* We only need to store one reference for each buffer, so avoid storing
-    * consecutive references for the same buffer. It might not be the more 
-    * common pasttern, but it is easy to implement.
+    * consecutive references for the same buffer. It might not be the most 
+    * common pattern, but it is easy to implement.
     */
-   if(vl->used && vl->buffers[vl->used - 1] == buf) {
+   if(vl->used && vl->entries[vl->used - 1].buf == buf) {
+      vl->entries[vl->used - 1].flags |= flags;
       return PIPE_OK;
    }
    
    /* Grow the table */
    if(vl->used == vl->size) {
       unsigned new_size;
-      struct pb_buffer **new_buffers;
+      struct pb_validate_entry *new_entries;
       
       new_size = vl->size * 2;
       if(!new_size)
 	 return PIPE_ERROR_OUT_OF_MEMORY;
 
-      new_buffers = (struct pb_buffer **)REALLOC(vl->buffers,
-                                                 vl->size*sizeof(struct pb_buffer *),
-                                                 new_size*sizeof(struct pb_buffer *));
-      if(!new_buffers)
+      new_entries = (struct pb_validate_entry *)REALLOC(vl->entries,
+                                                        vl->size*sizeof(struct pb_validate_entry),
+                                                        new_size*sizeof(struct pb_validate_entry));
+      if(!new_entries)
          return PIPE_ERROR_OUT_OF_MEMORY;
       
-      memset(new_buffers + vl->size, 0, (new_size - vl->size)*sizeof(struct pb_buffer *));
+      memset(new_entries + vl->size, 0, (new_size - vl->size)*sizeof(struct pb_validate_entry));
       
       vl->size = new_size;
-      vl->buffers = new_buffers;
+      vl->entries = new_entries;
    }
    
-   assert(!vl->buffers[vl->used]);
-   pb_reference(&vl->buffers[vl->used], buf);
+   assert(!vl->entries[vl->used].buf);
+   pb_reference(&vl->entries[vl->used].buf, buf);
+   vl->entries[vl->used].flags = flags;
    ++vl->used;
    
    return PIPE_OK;
@@ -100,10 +114,36 @@ pb_validate_add_buffer(struct pb_validate *vl,
 
 
 enum pipe_error
+pb_validate_foreach(struct pb_validate *vl,
+                    enum pipe_error (*callback)(struct pb_buffer *buf, void *data),
+                    void *data)
+{
+   unsigned i;
+   for(i = 0; i < vl->used; ++i) {
+      enum pipe_error ret;
+      ret = callback(vl->entries[i].buf, data);
+      if(ret != PIPE_OK)
+         return ret;
+   }
+   return PIPE_OK;
+}
+
+
+enum pipe_error
 pb_validate_validate(struct pb_validate *vl) 
 {
-   /* FIXME: go through each buffer, ensure its not mapped, its address is 
-    * available -- requires a new pb_buffer interface */
+   unsigned i;
+   
+   for(i = 0; i < vl->used; ++i) {
+      enum pipe_error ret;
+      ret = pb_validate(vl->entries[i].buf, vl, vl->entries[i].flags);
+      if(ret != PIPE_OK) {
+         while(i--)
+            pb_validate(vl->entries[i].buf, NULL, 0);
+         return ret;
+      }
+   }
+
    return PIPE_OK;
 }
 
@@ -114,8 +154,8 @@ pb_validate_fence(struct pb_validate *vl,
 {
    unsigned i;
    for(i = 0; i < vl->used; ++i) {
-      buffer_fence(vl->buffers[i], fence);
-      pb_reference(&vl->buffers[i], NULL);
+      pb_fence(vl->entries[i].buf, fence);
+      pb_reference(&vl->entries[i].buf, NULL);
    }
    vl->used = 0;
 }
@@ -126,8 +166,8 @@ pb_validate_destroy(struct pb_validate *vl)
 {
    unsigned i;
    for(i = 0; i < vl->used; ++i)
-      pb_reference(&vl->buffers[i], NULL);
-   FREE(vl->buffers);
+      pb_reference(&vl->entries[i].buf, NULL);
+   FREE(vl->entries);
    FREE(vl);
 }
 
@@ -142,8 +182,8 @@ pb_validate_create()
       return NULL;
    
    vl->size = PB_VALIDATE_INITIAL_SIZE;
-   vl->buffers = (struct pb_buffer **)CALLOC(vl->size, sizeof(struct pb_buffer *));
-   if(!vl->buffers) {
+   vl->entries = (struct pb_validate_entry *)CALLOC(vl->size, sizeof(struct pb_buffer *));
+   if(!vl->entries) {
       FREE(vl);
       return NULL;
    }
diff --git a/src/gallium/auxiliary/pipebuffer/pb_validate.h b/src/gallium/auxiliary/pipebuffer/pb_validate.h
index 3db1d5330b..dfb84df1ce 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_validate.h
+++ b/src/gallium/auxiliary/pipebuffer/pb_validate.h
@@ -58,7 +58,13 @@ struct pb_validate;
 
 enum pipe_error
 pb_validate_add_buffer(struct pb_validate *vl,
-                       struct pb_buffer *buf);
+                       struct pb_buffer *buf,
+                       unsigned flags);
+
+enum pipe_error
+pb_validate_foreach(struct pb_validate *vl,
+                    enum pipe_error (*callback)(struct pb_buffer *buf, void *data),
+                    void *data);
 
 /**
  * Validate all buffers for hardware access.
@@ -71,7 +77,7 @@ pb_validate_validate(struct pb_validate *vl);
 /**
  * Fence all buffers and clear the list.
  * 
- * Should be called right before issuing commands to the hardware.
+ * Should be called right after issuing commands to the hardware.
  */
 void
 pb_validate_fence(struct pb_validate *vl,
diff --git a/src/gallium/auxiliary/pipebuffer/pb_winsys.c b/src/gallium/auxiliary/pipebuffer/pb_winsys.c
index 28d137dbc4..45a883e532 100644
--- a/src/gallium/auxiliary/pipebuffer/pb_winsys.c
+++ b/src/gallium/auxiliary/pipebuffer/pb_winsys.c
@@ -30,7 +30,7 @@
  * Implementation of client buffer (also designated as "user buffers"), which
  * are just state-tracker owned data masqueraded as buffers.
  * 
- * \author José Fonseca <jrfonseca@tungstengraphics.com>
+ * \author Jose Fonseca <jrfonseca@tungstengraphics.com>
  */
 
 
@@ -91,6 +91,24 @@ pb_user_buffer_unmap(struct pb_buffer *buf)
 }
 
 
+static enum pipe_error 
+pb_user_buffer_validate(struct pb_buffer *buf, 
+                        struct pb_validate *vl,
+                        unsigned flags)
+{
+   assert(0);
+   return PIPE_ERROR;
+}
+
+
+static void
+pb_user_buffer_fence(struct pb_buffer *buf, 
+                     struct pipe_fence_handle *fence)
+{
+   assert(0);
+}
+
+
 static void
 pb_user_buffer_get_base_buffer(struct pb_buffer *buf,
                                struct pb_buffer **base_buf,
@@ -106,6 +124,8 @@ pb_user_buffer_vtbl = {
       pb_user_buffer_destroy,
       pb_user_buffer_map,
       pb_user_buffer_unmap,
+      pb_user_buffer_validate,
+      pb_user_buffer_fence,
       pb_user_buffer_get_base_buffer
 };