drm/i915: Move pinning of dev_priv->kernel_context into its creator

Rather than have every context ask "am I owned by the kernel? pin!",
move that logic into the creator of the kernel context, in order to
improve code comprehension.

v2: Throw away the user_handle on failure to allocate the ppgtt.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464098023-3294-5-git-send-email-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index a3f9adb..104d481 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -303,9 +303,7 @@ static struct i915_gem_context *
 i915_gem_create_context(struct drm_device *dev,
                        struct drm_i915_file_private *file_priv)
 {
-       const bool is_global_default_ctx = file_priv == NULL;
        struct i915_gem_context *ctx;
-       int ret = 0;
 
        lockdep_assert_held(&dev->struct_mutex);
 
@@ -313,30 +311,15 @@ i915_gem_create_context(struct drm_device *dev,
        if (IS_ERR(ctx))
                return ctx;
 
-       if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state) {
-               /* We may need to do things with the shrinker which
-                * require us to immediately switch back to the default
-                * context. This can cause a problem as pinning the
-                * default context also requires GTT space which may not
-                * 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(to_i915(dev)), 0);
-               if (ret) {
-                       DRM_DEBUG_DRIVER("Couldn't pin %d\n", ret);
-                       goto err_destroy;
-               }
-       }
-
        if (USES_FULL_PPGTT(dev)) {
                struct i915_hw_ppgtt *ppgtt = i915_ppgtt_create(dev, file_priv);
 
-               if (IS_ERR_OR_NULL(ppgtt)) {
+               if (IS_ERR(ppgtt)) {
                        DRM_DEBUG_DRIVER("PPGTT setup failed (%ld)\n",
                                         PTR_ERR(ppgtt));
-                       ret = PTR_ERR(ppgtt);
-                       goto err_unpin;
+                       idr_remove(&file_priv->context_idr, ctx->user_handle);
+                       i915_gem_context_unreference(ctx);
+                       return ERR_CAST(ppgtt);
                }
 
                ctx->ppgtt = ppgtt;
@@ -345,14 +328,6 @@ i915_gem_create_context(struct drm_device *dev,
        trace_i915_context_create(ctx);
 
        return ctx;
-
-err_unpin:
-       if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state)
-               i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
-err_destroy:
-       idr_remove(&file_priv->context_idr, ctx->user_handle);
-       i915_gem_context_unreference(ctx);
-       return ERR_PTR(ret);
 }
 
 static void i915_gem_context_unpin(struct i915_gem_context *ctx,
@@ -426,6 +401,26 @@ int i915_gem_context_init(struct drm_device *dev)
                return PTR_ERR(ctx);
        }
 
+       if (ctx->legacy_hw_ctx.rcs_state) {
+               int ret;
+
+               /* We may need to do things with the shrinker which
+                * require us to immediately switch back to the default
+                * context. This can cause a problem as pinning the
+                * default context also requires GTT space which may not
+                * 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_priv), 0);
+               if (ret) {
+                       DRM_ERROR("Failed to pinned default global context (error %d)\n",
+                                 ret);
+                       i915_gem_context_unreference(ctx);
+                       return ret;
+               }
+       }
+
        dev_priv->kernel_context = ctx;
 
        DRM_DEBUG_DRIVER("%s context support initialized\n",