drm/i915: Split intel_ring_begin

In preparation for handling ring seqno wrapping, split
intel_ring_begin into helper part which doesn't allocate
seqno.

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 22 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 36e1e13ae946..01a660a7c167 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1363,11 +1363,31 @@ intel_ring_alloc_seqno(struct intel_ring_buffer *ring)
         return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_request);
 }
 
+static int __intel_ring_begin(struct intel_ring_buffer *ring,
+                              int bytes)
+{
+        int ret;
+
+        if (unlikely(ring->tail + bytes > ring->effective_size)) {
+                ret = intel_wrap_ring_buffer(ring);
+                if (unlikely(ret))
+                        return ret;
+        }
+
+        if (unlikely(ring->space < bytes)) {
+                ret = ring_wait_for_space(ring, bytes);
+                if (unlikely(ret))
+                        return ret;
+        }
+
+        ring->space -= bytes;
+        return 0;
+}
+
 int intel_ring_begin(struct intel_ring_buffer *ring,
                      int num_dwords)
 {
         drm_i915_private_t *dev_priv = ring->dev->dev_private;
-        int n = 4*num_dwords;
         int ret;
 
         ret = i915_gem_check_wedge(dev_priv, dev_priv->mm.interruptible);
@@ -1379,20 +1399,7 @@ int intel_ring_begin(struct intel_ring_buffer *ring,
         if (ret)
                 return ret;
 
-        if (unlikely(ring->tail + n > ring->effective_size)) {
-                ret = intel_wrap_ring_buffer(ring);
-                if (unlikely(ret))
-                        return ret;
-        }
-
-        if (unlikely(ring->space < n)) {
-                ret = ring_wait_for_space(ring, n);
-                if (unlikely(ret))
-                        return ret;
-        }
-
-        ring->space -= n;
-        return 0;
+        return __intel_ring_begin(ring, num_dwords * sizeof(uint32_t));
 }
 
 void intel_ring_advance(struct intel_ring_buffer *ring)