[PATCH] drm: optimise i8x0 accesses..

This optimises the drm code to not do put_user() on memory the kernel
allocated and then mmap-installed to userspace, but instead makes it use
the kernel virtual address directly instead. 

From: Arjan van de Ven <arjanv@redhat.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/char/drm/i810_dma.c

@@ -844,13 +844,10 @@ static void i810_dma_dispatch_vertex(drm_device_t *dev,
 	if (buf_priv->currently_mapped == I810_BUF_MAPPED) {
 		unsigned int prim = (sarea_priv->vertex_prim & PR_MASK);
 
-		put_user((GFX_OP_PRIMITIVE | prim |
-					     ((used/4)-2)),
-		(u32 __user *)buf_priv->virtual);
+		*(u32 *)buf_priv->kernel_virtual = ((GFX_OP_PRIMITIVE | prim | ((used/4)-2)));
 
 		if (used & 4) {
-			put_user(0,
-			(u32 __user *)((u32)buf_priv->virtual + used));
+			*(u32 *)((u32)buf_priv->kernel_virtual + used) = 0;
 			used += 4;
 		}
 

drivers/char/drm/i830_dma.c

@@ -1166,19 +1166,19 @@ static void i830_dma_dispatch_vertex(drm_device_t *dev,
    	DRM_DEBUG(  "start + used - 4 : %ld\n", start + used - 4);
 
 	if (buf_priv->currently_mapped == I830_BUF_MAPPED) {
-		u32  __user *vp = buf_priv->virtual;
+		u32 *vp = buf_priv->kernel_virtual;
 
-		put_user( (GFX_OP_PRIMITIVE |
-			 sarea_priv->vertex_prim |
-			  ((used/4)-2)), &vp[0]);
+		vp[0] = (GFX_OP_PRIMITIVE |
+			sarea_priv->vertex_prim |
+			((used/4)-2));
 
 		if (dev_priv->use_mi_batchbuffer_start) {
-			put_user(MI_BATCH_BUFFER_END, &vp[used/4]);
+			vp[used/4] = MI_BATCH_BUFFER_END;
 			used += 4; 
 		}
 		
 		if (used & 4) {
-			put_user(0, &vp[used/4]);
+			vp[used/4] = 0;
 			used += 4;
 		}