drm/i915: Split the ringbuffers from the rings (2/3)

This refactoring has been performed using the following Coccinelle
semantic script:

    @@
    struct intel_engine_cs r;
    @@
    (
    - (r).obj
    + r.buffer->obj
    |
    - (r).virtual_start
    + r.buffer->virtual_start
    |
    - (r).head
    + r.buffer->head
    |
    - (r).tail
    + r.buffer->tail
    |
    - (r).space
    + r.buffer->space
    |
    - (r).size
    + r.buffer->size
    |
    - (r).effective_size
    + r.buffer->effective_size
    |
    - (r).last_retired_head
    + r.buffer->last_retired_head
    )

    @@
    struct intel_engine_cs *r;
    @@
    (
    - (r)->obj
    + r->buffer->obj
    |
    - (r)->virtual_start
    + r->buffer->virtual_start
    |
    - (r)->head
    + r->buffer->head
    |
    - (r)->tail
    + r->buffer->tail
    |
    - (r)->space
    + r->buffer->space
    |
    - (r)->size
    + r->buffer->size
    |
    - (r)->effective_size
    + r->buffer->effective_size
    |
    - (r)->last_retired_head
    + r->buffer->last_retired_head
    )

    @@
    expression E;
    @@
    (
    - LP_RING(E)->obj
    + LP_RING(E)->buffer->obj
    |
    - LP_RING(E)->virtual_start
    + LP_RING(E)->buffer->virtual_start
    |
    - LP_RING(E)->head
    + LP_RING(E)->buffer->head
    |
    - LP_RING(E)->tail
    + LP_RING(E)->buffer->tail
    |
    - LP_RING(E)->space
    + LP_RING(E)->buffer->space
    |
    - LP_RING(E)->size
    + LP_RING(E)->buffer->size
    |
    - LP_RING(E)->effective_size
    + LP_RING(E)->buffer->effective_size
    |
    - LP_RING(E)->last_retired_head
    + LP_RING(E)->buffer->last_retired_head
    )

Note: On top of this this patch also removes the now unused ringbuffer
fields in intel_engine_cs.

Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
[danvet: Add note about fixup patch included here.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_dma.c

@@ -64,7 +64,7 @@
  * has access to the ring.
  */
 #define RING_LOCK_TEST_WITH_RETURN(dev, file) do {			\
-	if (LP_RING(dev->dev_private)->obj == NULL)			\
+	if (LP_RING(dev->dev_private)->buffer->obj == NULL)			\
 		LOCK_TEST_WITH_RETURN(dev, file);			\
 } while (0)
 
@@ -149,17 +149,17 @@ void i915_kernel_lost_context(struct drm_device * dev)
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return;
 
-	ring->head = I915_READ_HEAD(ring) & HEAD_ADDR;
-	ring->tail = I915_READ_TAIL(ring) & TAIL_ADDR;
-	ring->space = ring->head - (ring->tail + I915_RING_FREE_SPACE);
-	if (ring->space < 0)
-		ring->space += ring->size;
+	ring->buffer->head = I915_READ_HEAD(ring) & HEAD_ADDR;
+	ring->buffer->tail = I915_READ_TAIL(ring) & TAIL_ADDR;
+	ring->buffer->space = ring->buffer->head - (ring->buffer->tail + I915_RING_FREE_SPACE);
+	if (ring->buffer->space < 0)
+		ring->buffer->space += ring->buffer->size;
 
 	if (!dev->primary->master)
 		return;
 
 	master_priv = dev->primary->master->driver_priv;
-	if (ring->head == ring->tail && master_priv->sarea_priv)
+	if (ring->buffer->head == ring->buffer->tail && master_priv->sarea_priv)
 		master_priv->sarea_priv->perf_boxes |= I915_BOX_RING_EMPTY;
 }
 
@@ -202,7 +202,7 @@ static int i915_initialize(struct drm_device * dev, drm_i915_init_t * init)
 	}
 
 	if (init->ring_size != 0) {
-		if (LP_RING(dev_priv)->obj != NULL) {
+		if (LP_RING(dev_priv)->buffer->obj != NULL) {
 			i915_dma_cleanup(dev);
 			DRM_ERROR("Client tried to initialize ringbuffer in "
 				  "GEM mode\n");
@@ -239,7 +239,7 @@ static int i915_dma_resume(struct drm_device * dev)
 
 	DRM_DEBUG_DRIVER("%s\n", __func__);
 
-	if (ring->virtual_start == NULL) {
+	if (ring->buffer->virtual_start == NULL) {
 		DRM_ERROR("can not ioremap virtual address for"
 			  " ring buffer\n");
 		return -ENOMEM;
@@ -361,7 +361,7 @@ static int i915_emit_cmds(struct drm_device * dev, int *buffer, int dwords)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int i, ret;
 
-	if ((dwords+1) * sizeof(int) >= LP_RING(dev_priv)->size - 8)
+	if ((dwords+1) * sizeof(int) >= LP_RING(dev_priv)->buffer->size - 8)
 		return -EINVAL;
 
 	for (i = 0; i < dwords;) {
@@ -824,7 +824,7 @@ static int i915_irq_emit(struct drm_device *dev, void *data,
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		return -ENODEV;
 
-	if (!dev_priv || !LP_RING(dev_priv)->virtual_start) {
+	if (!dev_priv || !LP_RING(dev_priv)->buffer->virtual_start) {
 		DRM_ERROR("called with no initialization\n");
 		return -EINVAL;
 	}