1 files changed, 151 insertions, 40 deletions

diff --git a/src/gallium/winsys/svga/drm/vmw_fence.c b/src/gallium/winsys/svga/drm/vmw_fence.c
index 754f8a666df..8af2250b7ea 100644
--- a/src/gallium/winsys/svga/drm/vmw_fence.c
+++ b/src/gallium/winsys/svga/drm/vmw_fence.c
@@ -22,20 +22,10 @@
  * SOFTWARE.
  *
  **********************************************************/
-/*
- * TODO:
- *
- * Fencing is currently a bit inefficient, since we need to call the
- * kernel do determine a fence object signaled status if the fence is not
- * signaled. This can be greatly improved upon by using the fact that the
- * execbuf ioctl returns the last signaled fence seqno, as does the
- * fence signaled ioctl. We should set up a ring of fence objects and
- * walk through them checking for signaled status each time we receive a
- * new passed fence seqno.
- */
-
 #include "util/u_memory.h"
 #include "util/u_atomic.h"
+#include "util/u_double_list.h"
+#include "os/os_thread.h"
 
 #include "pipebuffer/pb_buffer_fenced.h"
 
@@ -44,20 +34,129 @@
 
 struct vmw_fence_ops 
 {
+   /*
+    * Immutable members.
+    */
    struct pb_fence_ops base;
-
    struct vmw_winsys_screen *vws;
+
+   pipe_mutex mutex;
+
+   /*
+    * Protected by mutex;
+    */
+   struct list_head not_signaled;
+   uint32_t last_signaled;
+   uint32_t last_emitted;
 };
 
 struct vmw_fence
 {
+   struct list_head ops_list;
    int32_t refcount;
    uint32_t handle;
    uint32_t mask;
    int32_t signalled;
+   uint32_t seqno;
 };
 
 /**
+ * vmw_fence_seq_is_signaled - Check whether a fence seqno is
+ * signaled.
+ *
+ * @ops: Pointer to a struct pb_fence_ops.
+ *
+ */
+static INLINE boolean
+vmw_fence_seq_is_signaled(uint32_t seq, uint32_t last, uint32_t cur)
+{
+   return (cur - last <= cur - seq);
+}
+
+
+/**
+ * vmw_fence_ops - Return the vmw_fence_ops structure backing a
+ * struct pb_fence_ops pointer.
+ *
+ * @ops: Pointer to a struct pb_fence_ops.
+ *
+ */
+static INLINE struct vmw_fence_ops *
+vmw_fence_ops(struct pb_fence_ops *ops)
+{
+   assert(ops);
+   return (struct vmw_fence_ops *)ops;
+}
+
+
+/**
+ * vmw_fences_release - Release all fences from the not_signaled
+ * list.
+ *
+ * @ops: Pointer to a struct vmw_fence_ops.
+ *
+ */
+static void
+vmw_fences_release(struct vmw_fence_ops *ops)
+{
+   struct vmw_fence *fence, *n;
+
+   pipe_mutex_lock(ops->mutex);
+   LIST_FOR_EACH_ENTRY_SAFE(fence, n, &ops->not_signaled, ops_list)
+      LIST_DELINIT(&fence->ops_list);
+   pipe_mutex_unlock(ops->mutex);
+}
+
+/**
+ * vmw_fences_signal - Traverse the not_signaled list and try to
+ * signal unsignaled fences.
+ *
+ * @ops: Pointer to a struct pb_fence_ops.
+ * @signaled: Seqno that has signaled.
+ * @emitted: Last seqno emitted by the kernel.
+ * @has_emitted: Whether we provide the emitted value.
+ *
+ */
+void
+vmw_fences_signal(struct pb_fence_ops *fence_ops,
+                  uint32_t signaled,
+                  uint32_t emitted,
+                  boolean has_emitted)
+{
+   struct vmw_fence_ops *ops = NULL;
+   struct vmw_fence *fence, *n;
+
+   if (fence_ops == NULL)
+      return;
+
+   ops = vmw_fence_ops(fence_ops);
+   pipe_mutex_lock(ops->mutex);
+
+   if (!has_emitted) {
+      emitted = ops->last_emitted;
+      if (emitted - signaled > (1 << 30))
+	emitted = signaled;
+   }
+
+   if (signaled == ops->last_signaled && emitted == ops->last_emitted)
+      goto out_unlock;
+
+   LIST_FOR_EACH_ENTRY_SAFE(fence, n, &ops->not_signaled, ops_list) {
+      if (!vmw_fence_seq_is_signaled(fence->seqno, signaled, emitted))
+         break;
+
+      p_atomic_set(&fence->signalled, 1);
+      LIST_DELINIT(&fence->ops_list);
+   }
+   ops->last_signaled = signaled;
+   ops->last_emitted = emitted;
+
+out_unlock:
+   pipe_mutex_unlock(ops->mutex);
+}
+
+
+/**
  * vmw_fence - return the vmw_fence object identified by a
  * struct pipe_fence_handle *
  *
@@ -69,18 +168,22 @@ vmw_fence(struct pipe_fence_handle *fence)
    return (struct vmw_fence *) fence;
 }
 
+
 /**
  * vmw_fence_create - Create a user-space fence object.
  *
+ * @fence_ops: The fence_ops manager to register with.
  * @handle: Handle identifying the kernel fence object.
  * @mask: Mask of flags that this fence object may signal.
  *
  * Returns NULL on failure.
  */
 struct pipe_fence_handle *
-vmw_fence_create(uint32_t handle, uint32_t mask)
+vmw_fence_create(struct pb_fence_ops *fence_ops, uint32_t handle,
+                 uint32_t seqno, uint32_t mask)
 {
    struct vmw_fence *fence = CALLOC_STRUCT(vmw_fence);
+   struct vmw_fence_ops *ops = vmw_fence_ops(fence_ops);
 
    if (!fence)
       return NULL;
@@ -88,27 +191,24 @@ vmw_fence_create(uint32_t handle, uint32_t mask)
    p_atomic_set(&fence->refcount, 1);
    fence->handle = handle;
    fence->mask = mask;
+   fence->seqno = seqno;
    p_atomic_set(&fence->signalled, 0);
+   pipe_mutex_lock(ops->mutex);
+
+   if (vmw_fence_seq_is_signaled(seqno, ops->last_signaled, seqno)) {
+      p_atomic_set(&fence->signalled, 1);
+      LIST_INITHEAD(&fence->ops_list);
+   } else {
+      p_atomic_set(&fence->signalled, 0);
+      LIST_ADDTAIL(&fence->ops_list, &ops->not_signaled);
+   }
 
-   return (struct pipe_fence_handle *) fence;
-}
+   pipe_mutex_unlock(ops->mutex);
 
-/**
- * vmw_fence_ops - Return the vmw_fence_ops structure backing a
- * struct pb_fence_ops pointer.
- *
- * @ops: Pointer to a struct pb_fence_ops.
- *
- */
-static INLINE struct vmw_fence_ops *
-vmw_fence_ops(struct pb_fence_ops *ops)
-{
-   assert(ops);
-   return (struct vmw_fence_ops *)ops;
+   return (struct pipe_fence_handle *) fence;
 }
 
 
-
 /**
  * vmw_fence_reference - Reference / unreference a vmw fence object.
  *
@@ -125,7 +225,14 @@ vmw_fence_reference(struct vmw_winsys_screen *vws,
       struct vmw_fence *vfence = vmw_fence(*ptr);
 
       if (p_atomic_dec_zero(&vfence->refcount)) {
+         struct vmw_fence_ops *ops = vmw_fence_ops(vws->fence_ops);
+
 	 vmw_ioctl_fence_unref(vws, vfence->handle);
+
+         pipe_mutex_lock(ops->mutex);
+         LIST_DELINIT(&vfence->ops_list);
+         pipe_mutex_unlock(ops->mutex);
+
 	 FREE(vfence);
       }
    }
@@ -171,18 +278,21 @@ vmw_fence_signalled(struct vmw_winsys_screen *vws,
    if ((old & vflags) == vflags)
       return 0;
 
+   /*
+    * Currently we update signaled fences on each execbuf call.
+    * That should really be sufficient, and we can avoid
+    * a lot of kernel calls this way.
+    */
+#if 1
    ret = vmw_ioctl_fence_signalled(vws, vfence->handle, vflags);
 
-   if (ret == 0) {
-      int32_t prev = old;
-
-      do {
-	 old = prev;
-	 prev = p_atomic_cmpxchg(&vfence->signalled, old, old | vflags);
-      } while (prev != old);
-   }
-
+   if (ret == 0)
+      p_atomic_set(&vfence->signalled, 1);
    return ret;
+#else
+   (void) ret;
+   return -1;
+#endif
 }
 
 /**
@@ -287,6 +397,7 @@ vmw_fence_ops_fence_finish(struct pb_fence_ops *ops,
 static void
 vmw_fence_ops_destroy(struct pb_fence_ops *ops)
 {
+   vmw_fences_release(vmw_fence_ops(ops));
    FREE(ops);
 }
 
@@ -310,6 +421,8 @@ vmw_fence_ops_create(struct vmw_winsys_screen *vws)
    if(!ops)
       return NULL;
 
+   pipe_mutex_init(ops->mutex);
+   LIST_INITHEAD(&ops->not_signaled);
    ops->base.destroy = &vmw_fence_ops_destroy;
    ops->base.fence_reference = &vmw_fence_ops_fence_reference;
    ops->base.fence_signalled = &vmw_fence_ops_fence_signalled;
@@ -319,5 +432,3 @@ vmw_fence_ops_create(struct vmw_winsys_screen *vws)
 
    return &ops->base;
 }
-
-