drm/i915: Support LRC context single submission

This patch introduces the support of LRC context single submission.
As GVT context may come from different guests, which require different
configuration of render registers. It can't be combined into a dual ELSP
submission combo.

Only GVT-g will create this kinds of GEM context currently.

v8:

- Rename the data member in struct i915_gem_context. (Chris)

v7:

- Fix typos in commit message. (Joonas)

v6:
- Make GVT code as dead code when !CONFIG_DRM_I915_GVT. (Chris)

v5:

- Only compile this feature when CONFIG_DRM_I915_GVT=y. (Tvrtko)

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-9-git-send-email-zhi.a.wang@intel.com

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 85b92b285670a1f45d646f25d910b6a1e4febc86..34a1c185a0bcbd2a8cbb8ce0ea14f964b4bf609f 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -883,6 +883,7 @@ struct i915_gem_context {
        u32 ring_size;
        u32 desc_template;
        struct atomic_notifier_head status_notifier;
+       bool execlists_force_single_submission;
 
        struct list_head link;
 

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 67d19bd5a48117f7378ce0079a8ecfd8a503af68..debed011a9587f119a76cd3b05ed91540189ad72 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -444,6 +444,20 @@ static void execlists_context_unqueue(struct intel_engine_cs *engine)
                        i915_gem_request_unreference(req0);
                        req0 = cursor;
                } else {
+                       if (IS_ENABLED(CONFIG_DRM_I915_GVT)) {
+                               /*
+                                * req0 (after merged) ctx requires single
+                                * submission, stop picking
+                                */
+                               if (req0->ctx->execlists_force_single_submission)
+                                       break;
+                               /*
+                                * req0 ctx doesn't require single submission,
+                                * but next req ctx requires, stop picking
+                                */
+                               if (cursor->ctx->execlists_force_single_submission)
+                                       break;
+                       }
                        req1 = cursor;
                        WARN_ON(req1->elsp_submitted);
                        break;