[Intel-gfx] [PATCH 3/3] drm/i915/perf: enable OAR context save/restore of performance counters

Umesh Nerlige Ramappa umesh.nerlige.ramappa at intel.com
Mon Oct 14 18:55:31 UTC 2019


From: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

We want this so we can preempt performance queries and keep the system
responsive even when long running queries are ongoing. We avoid doing
it for all contexts.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 23 +++++---
 drivers/gpu/drm/i915/gt/intel_lrc.h |  3 +
 drivers/gpu/drm/i915/i915_perf.c    | 89 +++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 9d8eaf8edaab..1bab671dc7a0 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1218,6 +1218,19 @@ static bool can_merge_rq(const struct i915_request *prev,
 	return true;
 }
 
+u32 intel_lrc_make_ctx_control(const struct intel_engine_cs *engine)
+{
+	u32 value =
+		_MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT) |
+		_MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH);
+
+	if (INTEL_GEN(engine->i915) < 11)
+		value |= _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT |
+					    CTX_CTRL_RS_CTX_ENABLE);
+
+	return value;
+}
+
 static void virtual_update_register_offsets(u32 *regs,
 					    struct intel_engine_cs *engine)
 {
@@ -2124,6 +2137,7 @@ __execlists_update_reg_state(const struct intel_context *ce,
 
 		i915_oa_init_reg_state(ce, engine);
 	}
+	regs[CTX_CONTEXT_CONTROL] |= intel_lrc_make_ctx_control(engine);
 }
 
 static int
@@ -3628,14 +3642,7 @@ static void init_common_reg_state(u32 * const regs,
 				  const struct intel_engine_cs *engine,
 				  const struct intel_ring *ring)
 {
-	regs[CTX_CONTEXT_CONTROL] =
-		_MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT) |
-		_MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH);
-	if (INTEL_GEN(engine->i915) < 11)
-		regs[CTX_CONTEXT_CONTROL] |=
-			_MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT |
-					    CTX_CTRL_RS_CTX_ENABLE);
-
+	regs[CTX_CONTEXT_CONTROL] = intel_lrc_make_ctx_control(engine);
 	regs[CTX_RING_BUFFER_CONTROL] = RING_CTL_SIZE(ring->size) | RING_VALID;
 	regs[CTX_BB_STATE] = RING_BB_PPGTT;
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.h b/drivers/gpu/drm/i915/gt/intel_lrc.h
index 99dc576a4e25..6b2b196f09e7 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.h
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.h
@@ -43,6 +43,7 @@ struct intel_engine_cs;
 #define	  CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT	(1 << 0)
 #define   CTX_CTRL_RS_CTX_ENABLE		(1 << 1)
 #define	  CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT	(1 << 2)
+#define	  GEN12_CTX_CTRL_OAR_CONTEXT_ENABLE	(1 << 8)
 #define RING_CONTEXT_STATUS_PTR(base)		_MMIO((base) + 0x3a0)
 #define RING_EXECLIST_SQ_CONTENTS(base)		_MMIO((base) + 0x510)
 #define RING_EXECLIST_CONTROL(base)		_MMIO((base) + 0x550)
@@ -145,4 +146,6 @@ struct intel_engine_cs *
 intel_virtual_engine_get_sibling(struct intel_engine_cs *engine,
 				 unsigned int sibling);
 
+u32 intel_lrc_make_ctx_control(const struct intel_engine_cs *engine);
+
 #endif /* _INTEL_LRC_H_ */
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index df3b6976ba5b..d0ddd37dc078 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -2208,6 +2208,70 @@ static int gen8_configure_context(struct i915_gem_context *ctx,
 	return err;
 }
 
+static int gen12_emit_oar_config(struct intel_context *ce, bool enable)
+{
+	struct i915_request *rq;
+	u32 *cs, offset;
+	int err = 0;
+
+	rq = i915_request_create(ce);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
+
+	cs = intel_ring_begin(rq, 4);
+	if (IS_ERR(cs)) {
+		err = PTR_ERR(cs);
+		goto out;
+	}
+
+	offset = i915_ggtt_offset(ce->state) + LRC_STATE_PN * PAGE_SIZE;
+
+	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
+	*cs++ = offset + CTX_CONTEXT_CONTROL * sizeof(u32);
+	*cs++ = 0;
+	*cs++ = intel_lrc_make_ctx_control(ce->engine) |
+		(enable ?
+		 _MASKED_BIT_ENABLE(GEN12_CTX_CTRL_OAR_CONTEXT_ENABLE) :
+		 _MASKED_BIT_DISABLE(GEN12_CTX_CTRL_OAR_CONTEXT_ENABLE));
+
+	intel_ring_advance(rq, cs);
+
+out:
+	i915_request_add(rq);
+
+	return err;
+}
+
+static int gen12_configure_context_oar(struct i915_gem_context *ctx,
+				       bool enable)
+{
+	struct i915_gem_engines_iter it;
+	struct intel_context *ce;
+	int err = 0;
+
+	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
+		GEM_BUG_ON(ce == ce->engine->kernel_context);
+
+		if (ce->engine->class != RENDER_CLASS)
+			continue;
+
+		err = intel_context_lock_pinned(ce);
+		if (err)
+			break;
+
+		/* Otherwise OA settings will be set upon first use */
+		if (intel_context_is_pinned(ce))
+			err = gen12_emit_oar_config(ce, enable);
+
+		intel_context_unlock_pinned(ce);
+		if (err)
+			break;
+	}
+	i915_gem_context_unlock_engines(ctx);
+
+	return err;
+}
+
 /*
  * Manages updating the per-context aspects of the OA stream
  * configuration across all contexts.
@@ -2313,6 +2377,17 @@ static int lrc_configure_all_contexts(struct i915_perf_stream *stream,
 			return err;
 		}
 
+		/*
+		 * For Gen12, performance counters are context
+		 * saved/restored. Only enable it for the context that
+		 * requested this.
+		 */
+		if (ctx == stream->ctx && IS_GEN(i915, 12)) {
+			err = gen12_configure_context_oar(ctx, oa_config != NULL);
+			if (err)
+				return err;
+		}
+
 		spin_lock(&i915->gem.contexts.lock);
 		list_safe_reset_next(ctx, cn, link);
 		i915_gem_context_put(ctx);
@@ -2782,6 +2857,20 @@ void i915_oa_init_reg_state(const struct intel_context *ce,
 	stream = engine->i915->perf.exclusive_stream;
 	if (stream)
 		gen8_update_reg_state_unlocked(ce, stream);
+
+	/*
+	 * Enable context save & restore of performance counters for
+	 * the OAR unit only on the context selected for performance
+	 * queries.
+	 */
+	if (IS_GEN(engine->i915, 12)) {
+		u32 *regs = ce->lrc_reg_state;
+
+		regs[CTX_CONTEXT_CONTROL] |=
+			(stream && ce->gem_context == stream->ctx)  ?
+			_MASKED_BIT_ENABLE(GEN12_CTX_CTRL_OAR_CONTEXT_ENABLE) :
+			_MASKED_BIT_DISABLE(GEN12_CTX_CTRL_OAR_CONTEXT_ENABLE);
+	}
 }
 
 /**
-- 
2.20.1



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