drm/i915: Store preemption capability in engine->flags

Let's avoid having to delve down the pointer chain to see if the i915
device has support for preemption and store that on the engine, which
made the decision in the first place!

v2: Refactor common preemption policy between execlists/guc.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tomasz Lis <tomasz.lis@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180403183537.5522-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index 749f27916a02b91f86e93ad0add0c198c693ed86..97121230656cd8064ff6bb70d83312f5b9976ed2 100644 (file)
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -657,6 +657,16 @@ static void port_assign(struct execlist_port *port, struct i915_request *rq)
        port_set(port, i915_request_get(rq));
 }
 
+static inline int rq_prio(const struct i915_request *rq)
+{
+       return rq->priotree.priority;
+}
+
+static inline int port_prio(const struct execlist_port *port)
+{
+       return rq_prio(port_request(port));
+}
+
 static void guc_dequeue(struct intel_engine_cs *engine)
 {
        struct intel_engine_execlists * const execlists = &engine->execlists;
@@ -672,12 +682,12 @@ static void guc_dequeue(struct intel_engine_cs *engine)
        GEM_BUG_ON(rb_first(&execlists->queue) != rb);
 
        if (port_isset(port)) {
-               if (engine->i915->preempt_context) {
+               if (intel_engine_has_preemption(engine)) {
                        struct guc_preempt_work *preempt_work =
                                &engine->i915->guc.preempt_work[engine->id];
+                       int prio = execlists->queue_priority;
 
-                       if (execlists->queue_priority >
-                           max(port_request(port)->priotree.priority, 0)) {
+                       if (__execlists_need_preempt(prio, port_prio(port))) {
                                execlists_set_active(execlists,
                                                     EXECLISTS_ACTIVE_PREEMPT);
                                queue_work(engine->i915->guc.preempt_wq,

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 4d08875422b6338613db406b70053b7fc0524ad0..88472845ce96a8216e69c70e71fc08f659cda1b6 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -183,7 +183,8 @@ static inline bool need_preempt(const struct intel_engine_cs *engine,
                                const struct i915_request *last,
                                int prio)
 {
-       return engine->i915->preempt_context && prio > max(rq_prio(last), 0);
+       return (intel_engine_has_preemption(engine) &&
+               __execlists_need_preempt(prio, rq_prio(last)));
 }
 
 /**
@@ -2117,11 +2118,13 @@ static void execlists_set_default_submission(struct intel_engine_cs *engine)
        engine->unpark = NULL;
 
        engine->flags |= I915_ENGINE_SUPPORTS_STATS;
+       if (engine->i915->preempt_context)
+               engine->flags |= I915_ENGINE_HAS_PREEMPTION;
 
        engine->i915->caps.scheduler =
                I915_SCHEDULER_CAP_ENABLED |
                I915_SCHEDULER_CAP_PRIORITY;
-       if (engine->i915->preempt_context)
+       if (intel_engine_has_preemption(engine))
                engine->i915->caps.scheduler |= I915_SCHEDULER_CAP_PREEMPTION;
 }
 

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 40461e29cdabe1661313442364a5cbb5702f0c47..256d58487559288a189001feb5b37af39d8b9b7e 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -562,6 +562,7 @@ struct intel_engine_cs {
 
 #define I915_ENGINE_NEEDS_CMD_PARSER BIT(0)
 #define I915_ENGINE_SUPPORTS_STATS   BIT(1)
+#define I915_ENGINE_HAS_PREEMPTION   BIT(2)
        unsigned int flags;
 
        /*
@@ -621,16 +622,29 @@ struct intel_engine_cs {
        } stats;
 };
 
-static inline bool intel_engine_needs_cmd_parser(struct intel_engine_cs *engine)
+static inline bool
+intel_engine_needs_cmd_parser(const struct intel_engine_cs *engine)
 {
        return engine->flags & I915_ENGINE_NEEDS_CMD_PARSER;
 }
 
-static inline bool intel_engine_supports_stats(struct intel_engine_cs *engine)
+static inline bool
+intel_engine_supports_stats(const struct intel_engine_cs *engine)
 {
        return engine->flags & I915_ENGINE_SUPPORTS_STATS;
 }
 
+static inline bool
+intel_engine_has_preemption(const struct intel_engine_cs *engine)
+{
+       return engine->flags & I915_ENGINE_HAS_PREEMPTION;
+}
+
+static inline bool __execlists_need_preempt(int prio, int last)
+{
+       return prio > max(0, last);
+}
+
 static inline void
 execlists_set_active(struct intel_engine_execlists *execlists,
                     unsigned int bit)