[Intel-gfx] [PATCH v3 01/16] drm/i915: return context from i915_switch_context()

[Mika Kuoppala]

In preparation for the next commit, return context that
was switched to from i915_switch_context().

v2: context in return value instead of param. (Ben Widawsky)

Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h            |    5 +++--
 drivers/gpu/drm/i915/i915_gem.c            |    8 ++++---
 drivers/gpu/drm/i915/i915_gem_context.c    |   32 +++++++++++++++++-----------
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    7 ++++--
 4 files changed, 32 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 44fca0b..630982b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1687,8 +1687,9 @@ struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
 void i915_gem_context_init(struct drm_device *dev);
 void i915_gem_context_fini(struct drm_device *dev);
 void i915_gem_context_close(struct drm_device *dev, struct drm_file *file);
-int i915_switch_context(struct intel_ring_buffer *ring,
-			struct drm_file *file, int to_id);
+struct i915_hw_context * __must_check
+i915_switch_context(struct intel_ring_buffer *ring,
+		    struct drm_file *file, int to_id);
 int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
 				  struct drm_file *file);
 int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 911bd40..db804cc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2522,9 +2522,11 @@ int i915_gpu_idle(struct drm_device *dev)
 
 	/* Flush everything onto the inactive list. */
 	for_each_ring(ring, dev_priv, i) {
-		ret = i915_switch_context(ring, NULL, DEFAULT_CONTEXT_ID);
-		if (ret)
-			return ret;
+		struct i915_hw_context *ctx;
+
+		ctx = i915_switch_context(ring, NULL, DEFAULT_CONTEXT_ID);
+		if (IS_ERR(ctx))
+			return PTR_ERR(ctx);
 
 		ret = intel_ring_idle(ring);
 		if (ret)
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 94d873a..ddf26a6 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -417,41 +417,47 @@ static int do_switch(struct i915_hw_context *to)
 /**
  * i915_switch_context() - perform a GPU context switch.
  * @ring: ring for which we'll execute the context switch
- * @file_priv: file_priv associated with the context, may be NULL
- * @id: context id number
- * @seqno: sequence number by which the new context will be switched to
- * @flags:
+ * @file: file associated with the context, may be NULL
+ * @to_id: context id number
+ * @return: context that was switched to or ERR_PTR on error
  *
  * The context life cycle is simple. The context refcount is incremented and
  * decremented by 1 and create and destroy. If the context is in use by the GPU,
  * it will have a refoucnt > 1. This allows us to destroy the context abstract
  * object while letting the normal object tracking destroy the backing BO.
  */
-int i915_switch_context(struct intel_ring_buffer *ring,
-			struct drm_file *file,
-			int to_id)
+
+struct i915_hw_context *
+i915_switch_context(struct intel_ring_buffer *ring,
+		    struct drm_file *file,
+		    int to_id)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
-	struct i915_hw_context *to;
+	struct i915_hw_context *to = NULL;
+	int ret = 0;
 
 	if (dev_priv->hw_contexts_disabled)
-		return 0;
+		return NULL;
 
 	if (ring != &dev_priv->ring[RCS])
-		return 0;
+		return NULL;
 
 	if (to_id == DEFAULT_CONTEXT_ID) {
 		to = ring->default_context;
 	} else {
 		if (file == NULL)
-			return -EINVAL;
+			return ERR_PTR(-EINVAL);
 
 		to = i915_gem_context_get(file->driver_priv, to_id);
 		if (to == NULL)
-			return -ENOENT;
+			return ERR_PTR(-ENOENT);
 	}
 
-	return do_switch(to);
+	ret = do_switch(to);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return to;
 }
 
 int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index a96b6a3..e0686ca 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -841,6 +841,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	struct drm_i915_gem_object *batch_obj;
 	struct drm_clip_rect *cliprects = NULL;
 	struct intel_ring_buffer *ring;
+	struct i915_hw_context *ctx;
 	u32 ctx_id = i915_execbuffer2_get_context_id(*args);
 	u32 exec_start, exec_len;
 	u32 mask, flags;
@@ -1023,9 +1024,11 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
 	if (ret)
 		goto err;
 
-	ret = i915_switch_context(ring, file, ctx_id);
-	if (ret)
+	ctx = i915_switch_context(ring, file, ctx_id);
+	if (IS_ERR(ctx)) {
+		ret = PTR_ERR(ctx);
 		goto err;
+	}
 
 	if (ring == &dev_priv->ring[RCS] &&
 	    mode != dev_priv->relative_constants_mode) {
-- 
1.7.9.5