drm/i915/gt: Push context state allocation earlier

Allow for knowledgeable users to preallocate the context state, and to
separate the allocation step from the pinning step during
intel_context_pin()

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200109085717.873326-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 5ea8305..bc5ae18 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -43,24 +43,42 @@ intel_context_create(struct intel_engine_cs *engine)
        return ce;
 }
 
+int intel_context_alloc_state(struct intel_context *ce)
+{
+       int err = 0;
+
+       if (mutex_lock_interruptible(&ce->pin_mutex))
+               return -EINTR;
+
+       if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
+               err = ce->ops->alloc(ce);
+               if (unlikely(err))
+                       goto unlock;
+
+               set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
+       }
+
+unlock:
+       mutex_unlock(&ce->pin_mutex);
+       return err;
+}
+
 int __intel_context_do_pin(struct intel_context *ce)
 {
        int err;
 
+       if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
+               err = intel_context_alloc_state(ce);
+               if (err)
+                       return err;
+       }
+
        if (mutex_lock_interruptible(&ce->pin_mutex))
                return -EINTR;
 
        if (likely(!atomic_read(&ce->pin_count))) {
                intel_wakeref_t wakeref;
 
-               if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
-                       err = ce->ops->alloc(ce);
-                       if (unlikely(err))
-                               goto err;
-
-                       __set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
-               }
-
                err = 0;
                with_intel_runtime_pm(ce->engine->uncore->rpm, wakeref)
                        err = ce->ops->pin(ce);

diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index 63073eb..e4a71da 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -31,6 +31,8 @@ void intel_context_fini(struct intel_context *ce);
 struct intel_context *
 intel_context_create(struct intel_engine_cs *engine);
 
+int intel_context_alloc_state(struct intel_context *ce);
+
 void intel_context_free(struct intel_context *ce);
 
 /**