Back up DRI offscreen memory before leaving VT and restore it

when entering VT. It may be overwritten in between.
Use PCI DMA blit for this if available.

4 files changed, 98 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 21d1235..6b93396 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2006-12-06  Thomas Hellstrom  <thomas-at-tungstengraphics-dot-com> 
+
+	* unichrome/via_dri.c: (viaDRIOffscreenSave),
+	(viaDRIOffscreenRestore):
+	* unichrome/via_driver.c: (VIAEnterVT), (VIALeaveVT):
+	* unichrome/via_driver.h:
+
+	Back up DRI offscreen memory before leaving VT and restore it
+	when entering VT. It may be overwritten in between.
+	Use PCI DMA blit for this if available.
+	
 2006-12-05  Thomas Hellstrom  <thomas-at-tungstengraphics-dot-com> 
 
 	* unichrome/via_driver.c: (VIAWriteMode), (VIAInitialize3DEngine):
diff --git a/unichrome/via_dri.c b/unichrome/via_dri.c
index d0225f0..2c1b8f9 100644
--- a/unichrome/via_dri.c
+++ b/unichrome/via_dri.c
@@ -998,3 +998,83 @@ static Bool VIADRIMapInit(ScreenPtr pScreen, VIAPtr pVia)
     
     return TRUE;
 }
+
+void 
+viaDRIOffscreenSave(ScrnInfoPtr pScrn)
+{
+    VIAPtr pVia = VIAPTR(pScrn);
+    VIADRIPtr pVIADRI = pVia->pDRIInfo->devPrivate;
+    unsigned char *saveAddr = pVia->FBBase + pVIADRI->fbOffset; 
+    unsigned long saveSize = pVIADRI->fbSize;
+    drm_via_dmablit_t blit;
+    int err;
+    
+
+    if (pVia->driOffScreenSave)
+	free(pVia->driOffScreenSave);
+
+    pVia->driOffScreenSave = malloc(saveSize + 16);
+    if (pVia->driOffScreenSave) {
+        if ((pVia->drmVerMajor == 2) && (pVia->drmVerMinor >= 8)) {
+	 
+	    blit.num_lines = 1;
+	    blit.line_length = saveSize;
+	    blit.fb_addr = pVIADRI->fbOffset;
+	    blit.fb_stride = ALIGN_TO(saveSize, 16);
+	    blit.mem_addr = (void *)ALIGN_TO((unsigned long) 
+					     pVia->driOffScreenSave, 16);
+	    blit.mem_stride = blit.fb_stride;
+	    blit.to_fb = 0;
+
+	    do {
+		err = drmCommandWriteRead(pVia->drmFD, DRM_VIA_DMA_BLIT, 
+					  &blit, sizeof(blit));
+	    } while (-EAGAIN == err);
+	    if (err) 
+		goto out_err;
+
+	    do {
+		err = drmCommandWriteRead(pVia->drmFD, DRM_VIA_BLIT_SYNC, 
+					  &blit.sync, sizeof(blit.sync));
+	    } while (-EAGAIN == err);
+	    if (err)
+		goto out_err;
+
+	} else {
+	    memcpy((void *)ALIGN_TO((unsigned long) pVia->driOffScreenSave, 16),
+		   saveAddr, saveSize);
+	}
+    } else {
+	xf86DrvMsg(pScrn->scrnIndex, X_ERROR, 
+		   "Out of memory trying to backup DRI offscreen memory.\n");
+    }
+    return;
+    
+  out_err:
+    xf86DrvMsg(pScrn->scrnIndex, X_WARNING, 
+	       "Hardware backup of DRI offscreen memory failed.\n"
+	       "\tUsing slow software backup instead.\n");
+
+    memcpy((void *)ALIGN_TO((unsigned long) pVia->driOffScreenSave, 16),
+	   saveAddr, saveSize);
+    return;
+}
+
+
+void 
+viaDRIOffscreenRestore(ScrnInfoPtr pScrn)
+{
+    VIAPtr pVia = VIAPTR(pScrn);
+    VIADRIPtr pVIADRI = pVia->pDRIInfo->devPrivate;
+
+    unsigned char *saveAddr = pVia->FBBase + pVIADRI->fbOffset; 
+    unsigned long saveSize = pVIADRI->fbSize;
+
+    if (pVia->driOffScreenSave) {
+	memcpy(saveAddr, 
+	       (void *)ALIGN_TO((unsigned long)pVia->driOffScreenSave, 16),
+	       saveSize);
+	free(pVia->driOffScreenSave);
+	pVia->driOffScreenSave = NULL;
+    }
+}
diff --git a/unichrome/via_driver.c b/unichrome/via_driver.c
index acbe3c8..7c441be 100644
--- a/unichrome/via_driver.c
+++ b/unichrome/via_driver.c
@@ -1644,6 +1644,7 @@ static Bool VIAEnterVT(int scrnIndex, int flags)
 #ifdef XF86DRI
     if (pVia->directRenderingEnabled) {
         kickVblank(pScrn);
+	viaDRIOffscreenRestore(pScrn);
 	VIADRIRingBufferInit(pScrn);
 	DRIUnlock(screenInfo.screens[scrnIndex]);
     }
@@ -1677,8 +1678,8 @@ static void VIALeaveVT(int scrnIndex, int flags)
 
 #ifdef XF86DRI
     if (pVia->directRenderingEnabled) {
-
-	VIADRIRingBufferCleanup(pScrn); 
+	VIADRIRingBufferCleanup(pScrn);
+	viaDRIOffscreenSave(pScrn);
     }
 #endif
 
diff --git a/unichrome/via_driver.h b/unichrome/via_driver.h
index 533e490..cc26a11 100644
--- a/unichrome/via_driver.h
+++ b/unichrome/via_driver.h
@@ -330,6 +330,7 @@ typedef struct _VIA {
     int                 drmVerMinor;
     int                 drmVerPL;
     VIAMem              driOffScreenMem;
+    void *              driOffScreenSave;
 #endif
     Bool		DRIIrqEnable;
     Bool                agpEnable;
@@ -457,6 +458,9 @@ void VIADRICloseScreen(ScreenPtr pScreen);
 Bool VIADRIFinishScreenInit(ScreenPtr pScreen);
 void VIADRIRingBufferCleanup(ScrnInfoPtr pScrn);
 Bool VIADRIRingBufferInit(ScrnInfoPtr pScrn);
+void viaDRIOffscreenRestore(ScrnInfoPtr pScrn);
+void viaDRIOffscreenSave(ScrnInfoPtr pScrn);
+
 #endif /* XF86DRI */
 
 #endif /* _VIA_DRIVER_H_ */