Add an EXA driver callback to determine whether a pixmap is

"offscreen" in exa terms, which means accessible to the GPU.
Bump exa minor. The change is backwards-compatible.

exa/exa.c

@@ -322,6 +322,9 @@ exaPixmapIsOffscreen(PixmapPtr p)
     if (p->devPrivate.ptr == NULL)
 	return TRUE;
 
+    if (pExaScr->info->PixmapIsOffscreen)
+	return pExaScr->info->PixmapIsOffscreen(p);
+
     return ((unsigned long) ((CARD8 *) p->devPrivate.ptr -
 			     (CARD8 *) pExaScr->info->memoryBase) <
 	    pExaScr->info->memorySize);

exa/exa.h

@@ -39,7 +39,7 @@
 #include "fb.h"
 
 #define EXA_VERSION_MAJOR   2
-#define EXA_VERSION_MINOR   1
+#define EXA_VERSION_MINOR   2
 #define EXA_VERSION_RELEASE 0
 
 typedef struct _ExaOffscreenArea ExaOffscreenArea;
@@ -636,6 +636,23 @@ typedef struct _ExaDriver {
      */
     void	(*FinishAccess)(PixmapPtr pPix, int index);
 
+    /**
+     * PixmapIsOffscreen() is an optional driver replacement to
+     * exaPixmapIsOffscreen(). Set to NULL if you want the standard behaviour
+     * of exaPixmapIsOffscreen().
+     *
+     * @param pPix the pixmap
+     * @return TRUE if the given drawable is in framebuffer memory.
+     *
+     * exaPixmapIsOffscreen() is used to determine if a pixmap is in offscreen
+     * memory, meaning that acceleration could probably be done to it, and that it
+     * will need to be wrapped by PrepareAccess()/FinishAccess() when accessing it
+     * with the CPU.
+     *
+     *
+     */
+    Bool	(*PixmapIsOffscreen)(PixmapPtr pPix);
+
 	/** @name PrepareAccess() and FinishAccess() indices
 	 * @{
 	 */