drm/i915: fixup __iomem mixups in ringbuffer.c

Two things:
- ring->virtual start is an __iomem pointer, treat it accordingly.
- dev_priv->status_page.page_addr is now always a cpu addr, no pointer
  casting needed for that.

Take the opportunity to remove the unnecessary drm indirection when
setting up the ringbuffer iomapping.

v2: Add a compiler barrier before reading the hw status page.

Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_dma.c

@@ -256,7 +256,7 @@ static int i915_dma_resume(struct drm_device * dev)
 
 	DRM_DEBUG_DRIVER("%s\n", __func__);
 
-	if (ring->map.handle == NULL) {
+	if (ring->virtual_start == NULL) {
 		DRM_ERROR("can not ioremap virtual address for"
 			  " ring buffer\n");
 		return -ENOMEM;

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -977,20 +977,14 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 	if (ret)
 		goto err_unref;
 
-	ring->map.size = ring->size;
-	ring->map.offset = dev->agp->base + obj->gtt_offset;
-	ring->map.type = 0;
-	ring->map.flags = 0;
-	ring->map.mtrr = 0;
-
-	drm_core_ioremap_wc(&ring->map, dev);
-	if (ring->map.handle == NULL) {
+	ring->virtual_start = ioremap_wc(dev->agp->base + obj->gtt_offset,
+					 ring->size);
+	if (ring->virtual_start == NULL) {
 		DRM_ERROR("Failed to map ringbuffer.\n");
 		ret = -EINVAL;
 		goto err_unpin;
 	}
 
-	ring->virtual_start = ring->map.handle;
 	ret = ring->init(ring);
 	if (ret)
 		goto err_unmap;
@@ -1006,7 +1000,7 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 	return 0;
 
 err_unmap:
-	drm_core_ioremapfree(&ring->map, dev);
+	iounmap(ring->virtual_start);
 err_unpin:
 	i915_gem_object_unpin(obj);
 err_unref:
@@ -1034,7 +1028,7 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
 
 	I915_WRITE_CTL(ring, 0);
 
-	drm_core_ioremapfree(&ring->map, ring->dev);
+	iounmap(ring->virtual_start);
 
 	i915_gem_object_unpin(ring->obj);
 	drm_gem_object_unreference(&ring->obj->base);
@@ -1048,7 +1042,7 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring)
 
 static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring)
 {
-	unsigned int *virt;
+	uint32_t __iomem *virt;
 	int rem = ring->size - ring->tail;
 
 	if (ring->space < rem) {
@@ -1057,12 +1051,10 @@ static int intel_wrap_ring_buffer(struct intel_ring_buffer *ring)
 			return ret;
 	}
 
-	virt = (unsigned int *)(ring->virtual_start + ring->tail);
-	rem /= 8;
-	while (rem--) {
-		*virt++ = MI_NOOP;
-		*virt++ = MI_NOOP;
-	}
+	virt = ring->virtual_start + ring->tail;
+	rem /= 4;
+	while (rem--)
+		iowrite32(MI_NOOP, virt++);
 
 	ring->tail = 0;
 	ring->space = ring_space(ring);
@@ -1427,20 +1419,13 @@ int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size)
 	if (IS_I830(ring->dev))
 		ring->effective_size -= 128;
 
-	ring->map.offset = start;
-	ring->map.size = size;
-	ring->map.type = 0;
-	ring->map.flags = 0;
-	ring->map.mtrr = 0;
-
-	drm_core_ioremap_wc(&ring->map, dev);
-	if (ring->map.handle == NULL) {
+	ring->virtual_start = ioremap_wc(start, size);
+	if (ring->virtual_start == NULL) {
 		DRM_ERROR("can not ioremap virtual address for"
 			  " ring buffer\n");
 		return -ENOMEM;
 	}
 
-	ring->virtual_start = (void __force __iomem *)ring->map.handle;
 	return 0;
 }
 

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -2,7 +2,7 @@
 #define _INTEL_RINGBUFFER_H_
 
 struct  intel_hw_status_page {
-	u32	__iomem	*page_addr;
+	u32		*page_addr;
 	unsigned int	gfx_addr;
 	struct		drm_i915_gem_object *obj;
 };
@@ -115,7 +115,6 @@ struct  intel_ring_buffer {
 	u32 outstanding_lazy_request;
 
 	wait_queue_head_t irq_queue;
-	drm_local_map_t map;
 
 	void *private;
 };
@@ -149,7 +148,9 @@ static inline u32
 intel_read_status_page(struct intel_ring_buffer *ring,
 		       int reg)
 {
-	return ioread32(ring->status_page.page_addr + reg);
+	/* Ensure that the compiler doesn't optimize away the load. */
+	barrier();
+	return ring->status_page.page_addr[reg];
 }
 
 /**