[PATCH 2/7] drm/i915: Move context special case to get()

[ben at bwidawsk.net (Ben Widawsky)]

This allows us to make upcoming refcounting code a bit simpler, and
cleaner. In addition, I think it makes the interface a bit nicer if the
caller doesn't need to figure out default contexts and such.

The interface works very similarly to the gem object ref counting, and
I believe it makes sense to do so as we'll use it in a very similar way
to objects (we currently use objects as a somewhat hackish way to manage
context lifecycles).

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_gem_context.c | 34 +++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index aa080ea..6211637 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -95,8 +95,6 @@
  */
 #define CONTEXT_ALIGN (64<<10)
 
-static struct i915_hw_context *
-i915_gem_context_get(struct drm_i915_file_private *file_priv, u32 id);
 static int do_switch(struct i915_hw_context *to);
 
 static int get_context_size(struct drm_device *dev)
@@ -291,9 +289,18 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
 }
 
 static struct i915_hw_context *
-i915_gem_context_get(struct drm_i915_file_private *file_priv, u32 id)
+i915_gem_context_get(struct intel_ring_buffer *ring,
+		     struct drm_i915_file_private *file_priv, u32 id)
 {
-	return (struct i915_hw_context *)idr_find(&file_priv->context_idr, id);
+	struct i915_hw_context *ctx;
+
+	if (id == DEFAULT_CONTEXT_ID)
+		ctx = ring->default_context;
+	else
+		ctx = (struct i915_hw_context *)
+			idr_find(&file_priv->context_idr, id);
+
+	return ctx;
 }
 
 static inline int
@@ -440,16 +447,12 @@ int i915_switch_context(struct intel_ring_buffer *ring,
 	if (ring != &dev_priv->ring[RCS])
 		return 0;
 
-	if (to_id == DEFAULT_CONTEXT_ID) {
-		to = ring->default_context;
-	} else {
-		if (file == NULL)
-			return -EINVAL;
+	if (file == NULL)
+		return -EINVAL;
 
-		to = i915_gem_context_get(file->driver_priv, to_id);
-		if (to == NULL)
-			return -ENOENT;
-	}
+	to = i915_gem_context_get(ring, file->driver_priv, to_id);
+	if (to == NULL)
+		return -ENOENT;
 
 	return do_switch(to);
 }
@@ -495,11 +498,14 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
 	if (!(dev->driver->driver_features & DRIVER_GEM))
 		return -ENODEV;
 
+	if (args->ctx_id == DEFAULT_CONTEXT_ID)
+		return -ENOENT;
+
 	ret = i915_mutex_lock_interruptible(dev);
 	if (ret)
 		return ret;
 
-	ctx = i915_gem_context_get(file_priv, args->ctx_id);
+	ctx = i915_gem_context_get(NULL, file_priv, args->ctx_id);
 	if (!ctx) {
 		mutex_unlock(&dev->struct_mutex);
 		return -ENOENT;
-- 
1.8.2