[CI 05/10] drm/i915: Move pinning of dev_priv->kernel_context into its creator

Chris Wilson
2016-05-24T13:53:58Z

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>
---
drivers/gpu/drm/i915/i915_gem_context.c | 53 +++++++++++++++------------------
1 file changed, 24 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index a3f9adb22a73..104d4819aca8 100644
--- 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",