drm/i915/guc: Do not conflate lrc_desc with GuC id for registration

The LRC descriptor pool is going away. So, stop using it as a check for
context registration, use the GuC id instead (being the thing that
actually gets registered with the GuC).

Also, rename the set/clear/query helper functions for context id
mappings to better reflect their purpose and to differentiate from
other registration related helper functions.
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220302003357.4188363-2-John.C.Harrison@Intel.com

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -511,30 +511,19 @@ static inline bool guc_submission_initialized(struct intel_guc *guc)
 	return !!guc->lrc_desc_pool_vaddr;
 }
 
-static inline void reset_lrc_desc(struct intel_guc *guc, u32 id)
+static inline void _reset_lrc_desc(struct intel_guc *guc, u32 id)
 {
-	if (likely(guc_submission_initialized(guc))) {
 	struct guc_lrc_desc *desc = __get_lrc_desc(guc, id);
-		unsigned long flags;
 
 	memset(desc, 0, sizeof(*desc));
-
-		/*
-		 * xarray API doesn't have xa_erase_irqsave wrapper, so calling
-		 * the lower level functions directly.
-		 */
-		xa_lock_irqsave(&guc->context_lookup, flags);
-		__xa_erase(&guc->context_lookup, id);
-		xa_unlock_irqrestore(&guc->context_lookup, flags);
-	}
 }
 
-static inline bool lrc_desc_registered(struct intel_guc *guc, u32 id)
+static inline bool ctx_id_mapped(struct intel_guc *guc, u32 id)
 {
 	return __get_context(guc, id);
 }
 
-static inline void set_lrc_desc_registered(struct intel_guc *guc, u32 id,
+static inline void set_ctx_id_mapping(struct intel_guc *guc, u32 id,
 				      struct intel_context *ce)
 {
 	unsigned long flags;
@@ -548,6 +537,24 @@ static inline void set_lrc_desc_registered(struct intel_guc *guc, u32 id,
 	xa_unlock_irqrestore(&guc->context_lookup, flags);
 }
 
+static inline void clr_ctx_id_mapping(struct intel_guc *guc, u32 id)
+{
+	unsigned long flags;
+
+	if (unlikely(!guc_submission_initialized(guc)))
+		return;
+
+	_reset_lrc_desc(guc, id);
+
+	/*
+	 * xarray API doesn't have xa_erase_irqsave wrapper, so calling
+	 * the lower level functions directly.
+	 */
+	xa_lock_irqsave(&guc->context_lookup, flags);
+	__xa_erase(&guc->context_lookup, id);
+	xa_unlock_irqrestore(&guc->context_lookup, flags);
+}
+
 static void decr_outstanding_submission_g2h(struct intel_guc *guc)
 {
 	if (atomic_dec_and_test(&guc->outstanding_submission_g2h))
@@ -792,7 +799,7 @@ static int __guc_wq_item_append(struct i915_request *rq)
 	GEM_BUG_ON(!atomic_read(&ce->guc_id.ref));
 	GEM_BUG_ON(context_guc_id_invalid(ce));
 	GEM_BUG_ON(context_wait_for_deregister_to_register(ce));
-	GEM_BUG_ON(!lrc_desc_registered(ce_to_guc(ce), ce->guc_id.id));
+	GEM_BUG_ON(!ctx_id_mapped(ce_to_guc(ce), ce->guc_id.id));
 
 	/* Insert NOOP if this work queue item will wrap the tail pointer. */
 	if (wqi_size > wq_space_until_wrap(ce)) {
@@ -920,7 +927,7 @@ static int guc_dequeue_one_context(struct intel_guc *guc)
 	if (submit) {
 		struct intel_context *ce = request_to_scheduling_context(last);
 
-		if (unlikely(!lrc_desc_registered(guc, ce->guc_id.id) &&
+		if (unlikely(!ctx_id_mapped(guc, ce->guc_id.id) &&
 			     !intel_context_is_banned(ce))) {
 			ret = guc_lrc_desc_pin(ce, false);
 			if (unlikely(ret == -EPIPE)) {
@@ -1884,7 +1891,7 @@ static bool need_tasklet(struct intel_guc *guc, struct i915_request *rq)
 
 	return submission_disabled(guc) || guc->stalled_request ||
 		!i915_sched_engine_is_empty(sched_engine) ||
-		!lrc_desc_registered(guc, ce->guc_id.id);
+		!ctx_id_mapped(guc, ce->guc_id.id);
 }
 
 static void guc_submit_request(struct i915_request *rq)
@@ -1941,7 +1948,7 @@ static void __release_guc_id(struct intel_guc *guc, struct intel_context *ce)
 		else
 			ida_simple_remove(&guc->submission_state.guc_ids,
 					  ce->guc_id.id);
-		reset_lrc_desc(guc, ce->guc_id.id);
+		clr_ctx_id_mapping(guc, ce->guc_id.id);
 		set_context_guc_id_invalid(ce);
 	}
 	if (!list_empty(&ce->guc_id.link))
@@ -2237,10 +2244,10 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop)
 	GEM_BUG_ON(i915_gem_object_is_lmem(guc->ct.vma->obj) !=
 		   i915_gem_object_is_lmem(ce->ring->vma->obj));
 
-	context_registered = lrc_desc_registered(guc, desc_idx);
+	context_registered = ctx_id_mapped(guc, desc_idx);
 
-	reset_lrc_desc(guc, desc_idx);
-	set_lrc_desc_registered(guc, desc_idx, ce);
+	clr_ctx_id_mapping(guc, desc_idx);
+	set_ctx_id_mapping(guc, desc_idx, ce);
 
 	desc = __get_lrc_desc(guc, desc_idx);
 	desc->engine_class = engine_class_to_guc_class(engine->class);
@@ -2311,7 +2318,7 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop)
 		}
 		spin_unlock_irqrestore(&ce->guc_state.lock, flags);
 		if (unlikely(disabled)) {
-			reset_lrc_desc(guc, desc_idx);
+			clr_ctx_id_mapping(guc, desc_idx);
 			return 0;	/* Will get registered later */
 		}
 
@@ -2327,9 +2334,9 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop)
 		with_intel_runtime_pm(runtime_pm, wakeref)
 			ret = register_context(ce, loop);
 		if (unlikely(ret == -EBUSY)) {
-			reset_lrc_desc(guc, desc_idx);
+			clr_ctx_id_mapping(guc, desc_idx);
 		} else if (unlikely(ret == -ENODEV)) {
-			reset_lrc_desc(guc, desc_idx);
+			clr_ctx_id_mapping(guc, desc_idx);
 			ret = 0;	/* Will get registered later */
 		}
 	}
@@ -2516,7 +2523,7 @@ static bool context_cant_unblock(struct intel_context *ce)
 
 	return (ce->guc_state.sched_state & SCHED_STATE_NO_UNBLOCK) ||
 		context_guc_id_invalid(ce) ||
-		!lrc_desc_registered(ce_to_guc(ce), ce->guc_id.id) ||
+		!ctx_id_mapped(ce_to_guc(ce), ce->guc_id.id) ||
 		!intel_context_is_pinned(ce);
 }
 
@@ -2686,7 +2693,7 @@ static inline void guc_lrc_desc_unpin(struct intel_context *ce)
 	bool disabled;
 
 	GEM_BUG_ON(!intel_gt_pm_is_awake(gt));
-	GEM_BUG_ON(!lrc_desc_registered(guc, ce->guc_id.id));
+	GEM_BUG_ON(!ctx_id_mapped(guc, ce->guc_id.id));
 	GEM_BUG_ON(ce != __get_context(guc, ce->guc_id.id));
 	GEM_BUG_ON(context_enabled(ce));
 
@@ -2803,7 +2810,7 @@ static void guc_context_destroy(struct kref *kref)
 	 */
 	spin_lock_irqsave(&guc->submission_state.lock, flags);
 	destroy = submission_disabled(guc) || context_guc_id_invalid(ce) ||
-		!lrc_desc_registered(guc, ce->guc_id.id);
+		!ctx_id_mapped(guc, ce->guc_id.id);
 	if (likely(!destroy)) {
 		if (!list_empty(&ce->guc_id.link))
 			list_del_init(&ce->guc_id.link);
@@ -3046,7 +3053,7 @@ static void guc_signal_context_fence(struct intel_context *ce)
 static bool context_needs_register(struct intel_context *ce, bool new_guc_id)
 {
 	return (new_guc_id || test_bit(CONTEXT_LRCA_DIRTY, &ce->flags) ||
-		!lrc_desc_registered(ce_to_guc(ce), ce->guc_id.id)) &&
+		!ctx_id_mapped(ce_to_guc(ce), ce->guc_id.id)) &&
 		!submission_disabled(ce_to_guc(ce));
 }