[Intel-gfx] [RFC PATCH 3/4] drm/i915: add api to pin/unpin context state

[Robert Bragg]

This adds i915_gem_context_pin/unpin_state functions so that code
outside i915_gem_context.c can pin/unpin a context without duplicating
knowledge about the alignment constraints.

Signed-off-by: Robert Bragg <robert at sixbynine.org>
---
 drivers/gpu/drm/i915/i915_drv.h         |  4 ++++
 drivers/gpu/drm/i915/i915_gem_context.c | 30 +++++++++++++++++++++---------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3212d62..acaf76c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2675,6 +2675,10 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
 int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
 				   struct drm_file *file);
 
+int i915_gem_context_pin_state(struct drm_device *dev,
+			       struct intel_context *ctx);
+void i915_gem_context_unpin_state(struct intel_context *ctx);
+
 /* i915_gem_evict.c */
 int __must_check i915_gem_evict_something(struct drm_device *dev,
 					  struct i915_address_space *vm,
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index a5221d8..feb1a23 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -132,6 +132,20 @@ static int get_context_size(struct drm_device *dev)
 	return ret;
 }
 
+int i915_gem_context_pin_state(struct drm_device *dev,
+			       struct intel_context *ctx)
+{
+	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
+
+	return i915_gem_obj_ggtt_pin(ctx->legacy_hw_ctx.rcs_state,
+				     get_context_alignment(dev), 0);
+}
+
+void i915_gem_context_unpin_state(struct intel_context *ctx)
+{
+	i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
+}
+
 void i915_gem_context_free(struct kref *ctx_ref)
 {
 	struct intel_context *ctx = container_of(ctx_ref,
@@ -253,8 +267,7 @@ i915_gem_create_context(struct drm_device *dev,
 		 * be available. To avoid this we always pin the default
 		 * context.
 		 */
-		ret = i915_gem_obj_ggtt_pin(ctx->legacy_hw_ctx.rcs_state,
-					    get_context_alignment(dev), 0);
+		ret = i915_gem_context_pin_state(dev, ctx);
 		if (ret) {
 			DRM_DEBUG_DRIVER("Couldn't pin %d\n", ret);
 			goto err_destroy;
@@ -278,7 +291,7 @@ i915_gem_create_context(struct drm_device *dev,
 
 err_unpin:
 	if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state)
-		i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
+		i915_gem_context_unpin_state(ctx);
 err_destroy:
 	i915_gem_context_unreference(ctx);
 	return ERR_PTR(ret);
@@ -375,12 +388,12 @@ void i915_gem_context_fini(struct drm_device *dev)
 		if (dev_priv->ring[RCS].last_context == dctx) {
 			/* Fake switch to NULL context */
 			WARN_ON(dctx->legacy_hw_ctx.rcs_state->active);
-			i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
+			i915_gem_context_unpin_state(dctx);
 			i915_gem_context_unreference(dctx);
 			dev_priv->ring[RCS].last_context = NULL;
 		}
 
-		i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
+		i915_gem_context_unpin_state(dctx);
 	}
 
 	for (i = 0; i < I915_NUM_RINGS; i++) {
@@ -534,8 +547,7 @@ static int do_switch(struct intel_engine_cs *ring,
 
 	/* Trying to pin first makes error handling easier. */
 	if (ring == &dev_priv->ring[RCS]) {
-		ret = i915_gem_obj_ggtt_pin(to->legacy_hw_ctx.rcs_state,
-					    get_context_alignment(ring->dev), 0);
+		ret = i915_gem_context_pin_state(ring->dev, to);
 		if (ret)
 			return ret;
 	}
@@ -616,7 +628,7 @@ static int do_switch(struct intel_engine_cs *ring,
 		BUG_ON(from->legacy_hw_ctx.rcs_state->ring != ring);
 
 		/* obj is kept alive until the next request by its active ref */
-		i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);
+		i915_gem_context_unpin_state(from);
 		i915_gem_context_unreference(from);
 	}
 
@@ -643,7 +655,7 @@ done:
 
 unpin_out:
 	if (ring->id == RCS)
-		i915_gem_object_ggtt_unpin(to->legacy_hw_ctx.rcs_state);
+		i915_gem_context_unpin_state(to);
 	return ret;
 }
 
-- 
2.1.3