[Intel-gfx] [PATCH] drm/i915/perf: Enable application triggered OA reports

[Lionel Landwerlin]

Gen12 brought an important redesign of the OA unit, splitting it in 2
with a per context part (OAR) and a global part (OAG).

OAR deals with per context counters and implements the
MI_REPORT_PERF_COUNT command.

OAG deals with global counters and the OA buffer.

Unfortunately some of the counters available in OAG are not available
in OAR, for instance counters that would report global caches
utilization.

Since applications making use of this want to access those additional
OAG counters we can enable them to generate a report from their
command buffer into the OA buffer. This is somewhat equivalent to
having them doing their own MI_REPORT_PERF_COUNT. The application then
parse the OA buffer as they were doing previously, only looking for a
begin/end OA report with the appropriate reason field in the OA buffer
instead of using MI_REPORT_PERF_COUNT generated reports for begin/end.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 18 ++++++++++++++++++
 drivers/gpu/drm/i915/i915_perf.c            | 10 +++++++---
 drivers/gpu/drm/i915/i915_reg.h             |  2 ++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index e96cc7fa0936..552eadaa6f9a 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -1127,6 +1127,10 @@ static void gen9_whitelist_build(struct i915_wa_list *w)
 
 	/* WaSendPushConstantsFromMMIO:skl,bxt */
 	whitelist_reg(w, COMMON_SLICE_CHICKEN2);
+
+	/* Allow userspace trigger OA report generation in OA buffer. */
+	whitelist_reg(w, OAREPORTTRIG2);
+	whitelist_reg(w, OAREPORTTRIG6);
 }
 
 static void skl_whitelist_build(struct intel_engine_cs *engine)
@@ -1208,6 +1212,10 @@ static void cnl_whitelist_build(struct intel_engine_cs *engine)
 
 	/* WaEnablePreemptionGranularityControlByUMD:cnl */
 	whitelist_reg(w, GEN8_CS_CHICKEN1);
+
+	/* Allow userspace trigger OA report generation in OA buffer. */
+	whitelist_reg(w, OAREPORTTRIG2);
+	whitelist_reg(w, OAREPORTTRIG6);
 }
 
 static void icl_whitelist_build(struct intel_engine_cs *engine)
@@ -1237,6 +1245,12 @@ static void icl_whitelist_build(struct intel_engine_cs *engine)
 		whitelist_reg_ext(w, PS_INVOCATION_COUNT,
 				  RING_FORCE_TO_NONPRIV_ACCESS_RD |
 				  RING_FORCE_TO_NONPRIV_RANGE_4);
+
+		/*
+		 * Allow userspace trigger OA report generation in OA buffer.
+		 */
+		whitelist_reg(w, OAREPORTTRIG2);
+		whitelist_reg(w, OAREPORTTRIG6);
 		break;
 
 	case VIDEO_DECODE_CLASS:
@@ -1281,6 +1295,10 @@ static void tgl_whitelist_build(struct intel_engine_cs *engine)
 
 		/* Wa_1806527549:tgl */
 		whitelist_reg(w, HIZ_CHICKEN);
+
+		/* Allow userspace trigger OA report generation in OA buffer. */
+		whitelist_reg(w, GEN12_OAG_OAREPORTTRIG2);
+		whitelist_reg(w, GEN12_OAG_OAREPORTTRIG6);
 		break;
 	default:
 		break;
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 28e3d76fa2e6..ae935b1b1ae3 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1450,7 +1450,8 @@ static void gen8_init_oa_buffer(struct i915_perf_stream *stream)
 	 *  bit."
 	 */
 	intel_uncore_write(uncore, GEN8_OABUFFER, gtt_offset |
-		   OABUFFER_SIZE_16M | GEN8_OABUFFER_MEM_SELECT_GGTT);
+		   OABUFFER_SIZE_16M | GEN8_OABUFFER_MEM_SELECT_GGTT |
+		   GEN8_OABUFFER_EDGE_TRIGGER);
 	intel_uncore_write(uncore, GEN8_OATAILPTR, gtt_offset & GEN8_OATAILPTR_MASK);
 
 	/* Mark that we need updated tail pointers to read from... */
@@ -1503,7 +1504,8 @@ static void gen12_init_oa_buffer(struct i915_perf_stream *stream)
 	 *  bit."
 	 */
 	intel_uncore_write(uncore, GEN12_OAG_OABUFFER, gtt_offset |
-			   OABUFFER_SIZE_16M | GEN8_OABUFFER_MEM_SELECT_GGTT);
+			   OABUFFER_SIZE_16M | GEN8_OABUFFER_MEM_SELECT_GGTT |
+			   GEN12_OAG_OABUFFER_EDGE_TRIGGER);
 	intel_uncore_write(uncore, GEN12_OAG_OATAILPTR,
 			   gtt_offset & GEN12_OAG_OATAILPTR_MASK);
 
@@ -4481,8 +4483,10 @@ int i915_perf_ioctl_version(void)
 	 *
 	 * 5: Add DRM_I915_PERF_PROP_POLL_OA_PERIOD parameter that controls the
 	 *    interval for the hrtimer used to check for OA data.
+	 *
+	 * 6. Add edge trigger report generation support.
 	 */
-	return 5;
+	return 6;
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 17484345cb80..813ae77ffeb7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -661,6 +661,7 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 
 #define GEN8_OABUFFER_UDW _MMIO(0x23b4)
 #define GEN8_OABUFFER _MMIO(0x2b14)
+#define  GEN8_OABUFFER_EDGE_TRIGGER         (1 << 2)
 #define  GEN8_OABUFFER_MEM_SELECT_GGTT      (1 << 0)  /* 0: PPGTT, 1: GGTT */
 
 #define GEN7_OASTATUS1 _MMIO(0x2364)
@@ -712,6 +713,7 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define GEN12_OAG_OABUFFER  _MMIO(0xdb08)
 #define  GEN12_OAG_OABUFFER_BUFFER_SIZE_MASK  (0x7)
 #define  GEN12_OAG_OABUFFER_BUFFER_SIZE_SHIFT (3)
+#define  GEN12_OAG_OABUFFER_EDGE_TRIGGER      (1 << 2)
 #define  GEN12_OAG_OABUFFER_MEMORY_SELECT     (1 << 0) /* 0: PPGTT, 1: GGTT */
 
 #define GEN12_OAG_OAGLBCTXCTRL _MMIO(0x2b28)
-- 
2.26.0