Get EXA resizing working and document it.

man/nv.man

@@ -143,6 +143,15 @@ Enable or disable the hardware cursor.  Default: on.
 .TP
 .BI "Option \*qNoAccel\*q \*q" boolean \*q
 Disable or enable acceleration.  Default: acceleration is enabled.
+.TP
+.BI "Option \*qAccelMethod\*q \*q" string \*q
+Choose acceleration architecture, either \*qXAA\*q or \*qEXA\*q.
+XAA is the old but stable architecture.
+EXA is newer and supports resizing the desktop larger than it started out with RandR 1.2.
+If you choose to use EXA, you might also consider setting
+.B Option \*qMigrationHeuristic\*q \*qgreedy\*q
+to improve performance.
+Default: XAA.
 .\" ******************** end G80 section ********************
 .
 .SH "SEE ALSO"

src/g80_driver.c

@@ -133,6 +133,7 @@ G80FreeRec(ScrnInfoPtr pScrn)
 static Bool
 G80ResizeScreen(ScrnInfoPtr pScrn, int width, int height)
 {
+    ScreenPtr pScreen = pScrn->pScreen;
     G80Ptr pNv = G80PTR(pScrn);
     xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);
     int pitch = width * (pScrn->bitsPerPixel / 8);
@@ -143,8 +144,8 @@ G80ResizeScreen(ScrnInfoPtr pScrn, int width, int height)
     pScrn->virtualX = width;
     pScrn->virtualY = height;
 
-    /* Can resize if XAA is disabled */
-    if(!pNv->xaa) {
+    /* Can resize if XAA is disabled or EXA is enabled */
+    if(!pNv->xaa || pNv->exa) {
         (*pScrn->pScreen->GetScreenPixmap)(pScrn->pScreen)->devKind = pitch;
         pScrn->displayWidth = pitch / (pScrn->bitsPerPixel / 8);
 
@@ -156,6 +157,23 @@ G80ResizeScreen(ScrnInfoPtr pScrn, int width, int height)
         }
     }
 
+    /*
+     * If EXA is enabled, use exaOffscreenAlloc to carve out a chunk of memory
+     * for the screen.
+     */
+    if(pNv->exa) {
+        if(pNv->exaScreenArea)
+            exaOffscreenFree(pScreen, pNv->exaScreenArea);
+        pNv->exaScreenArea = exaOffscreenAlloc(pScreen, pitch * pScrn->virtualY,
+                                               256, TRUE, NULL, NULL);
+        if(!pNv->exaScreenArea || pNv->exaScreenArea->offset != 0) {
+            xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
+                       "Failed to reserve EXA memory for the screen or EXA "
+                       "returned an area with a nonzero offset.  Don't be "
+                       "surprised if your screen is corrupt.\n");
+        }
+    }
+
     return TRUE;
 }
 
@@ -362,7 +380,7 @@ G80PreInit(ScrnInfoPtr pScrn, int flags)
     G80DispCreateCrtcs(pScrn);
 
     /* We can grow the desktop if XAA is disabled */
-    if(!xf86InitialConfiguration(pScrn, pNv->NoAccel)) {
+    if(!xf86InitialConfiguration(pScrn, pNv->NoAccel || pNv->AccelMethod == EXA)) {
         xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
             "No valid initial configuration found\n");
         goto fail;
@@ -469,8 +487,13 @@ G80CloseScreen(int scrnIndex, ScreenPtr pScreen)
 
     if(pNv->xaa)
         XAADestroyInfoRec(pNv->xaa);
-    if(pNv->exa)
+    if(pNv->exa) {
+        if(pNv->exaScreenArea) {
+            exaOffscreenFree(pScreen, pNv->exaScreenArea);
+            pNv->exaScreenArea = NULL;
+        }
         exaDriverFini(pScrn->pScreen);
+    }
     xf86_cursors_fini(pScreen);
 
     if(xf86ServerIsExiting()) {

src/g80_exa.c

@@ -302,7 +302,7 @@ Bool G80ExaInit(ScreenPtr pScreen, ScrnInfoPtr pScrn)
     exa->exa_major         = EXA_VERSION_MAJOR;
     exa->exa_minor         = EXA_VERSION_MINOR;
     exa->memoryBase        = pNv->mem;
-    exa->offScreenBase     = pitch * pScrn->virtualY;
+    exa->offScreenBase     = 0;
     exa->memorySize        = pitch * pNv->offscreenHeight;
     exa->pixmapOffsetAlign = 256;
     exa->pixmapPitchAlign  = 256;

src/g80_type.h

@@ -60,6 +60,7 @@ typedef struct G80Rec {
 
     /* EXA */
     ExaDriverPtr        exa;
+    ExaOffscreenArea   *exaScreenArea;
 
     /* DMA command buffer */
     CARD32              dmaPut;