drm: radeon: Fix ring_rptr accesses.

The memory behind ring_rptr can either be in ioremapped memory
or a vmalloc() normal kernel memory buffer.

However, the code unconditionally uses DRM_{READ,WRITE}32() (and thus
readl() and writel()) to access it.

Basically, if RADEON_IS_AGP then it's ioremap()'d memory else it's
vmalloc'd memory.

Adjust all of the ring_rptr access code as needed.

While we're here, kill the 'scratch' pointer in drm_radeon_private.
It's only used in the one place where it is initialized.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/gpu/drm/radeon/radeon_drv.h b/drivers/gpu/drm/radeon/radeon_drv.h
index c608e22f..a253cf0 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.h
+++ b/drivers/gpu/drm/radeon/radeon_drv.h
@@ -160,10 +160,6 @@
 	RADEON_IS_IGPGART = 0x01000000UL,
 };
 
-#define GET_RING_HEAD(dev_priv)	(dev_priv->writeback_works ? \
-        DRM_READ32(  (dev_priv)->ring_rptr, 0 ) : RADEON_READ(RADEON_CP_RB_RPTR))
-#define SET_RING_HEAD(dev_priv,val)	DRM_WRITE32( (dev_priv)->ring_rptr, 0, (val) )
-
 typedef struct drm_radeon_freelist {
 	unsigned int age;
 	struct drm_buf *buf;
@@ -248,7 +244,6 @@
 	drm_radeon_freelist_t *head;
 	drm_radeon_freelist_t *tail;
 	int last_buf;
-	volatile u32 *scratch;
 	int writeback_works;
 
 	int usec_timeout;
@@ -338,6 +333,12 @@
 extern struct drm_ioctl_desc radeon_ioctls[];
 extern int radeon_max_ioctl;
 
+extern u32 radeon_get_ring_head(drm_radeon_private_t *dev_priv);
+extern void radeon_set_ring_head(drm_radeon_private_t *dev_priv, u32 val);
+
+#define GET_RING_HEAD(dev_priv)	radeon_get_ring_head(dev_priv)
+#define SET_RING_HEAD(dev_priv, val) radeon_set_ring_head(dev_priv, val)
+
 /* Check whether the given hardware address is inside the framebuffer or the
  * GART area.
  */
@@ -639,9 +640,9 @@
 
 #define RADEON_SCRATCHOFF( x )		(RADEON_SCRATCH_REG_OFFSET + 4*(x))
 
-#define GET_SCRATCH( x )	(dev_priv->writeback_works			\
-				? DRM_READ32( dev_priv->ring_rptr, RADEON_SCRATCHOFF(x) ) \
-				: RADEON_READ( RADEON_SCRATCH_REG0 + 4*(x) ) )
+extern u32 radeon_get_scratch(drm_radeon_private_t *dev_priv, int index);
+
+#define GET_SCRATCH(dev_priv, x) radeon_get_scratch(dev_priv, x)
 
 #define RADEON_GEN_INT_CNTL		0x0040
 #	define RADEON_CRTC_VBLANK_MASK		(1 << 0)