drm/i915/perf: Determine context valid in OA reports

When supporting OA for TGL, it was seen that the context valid bit in
the report ID was not defined, however revisiting the spec seems to have
this bit defined. The bit is used to determine if a context is valid on
a context switch and is essential to determine active and idle periods
for a context. Re-enable the context valid bit for gen12 platforms.

BSpec: 52196 (description of report_id)

v2: Include BSpec reference (Ashutosh)

Fixes: 00a7f0d7 ("drm/i915/tgl: Add perf support on TGL")
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230802202854.1224547-1-umesh.nerlige.ramappa@intel.com

drivers/gpu/drm/i915/i915_perf.c

@@ -483,8 +483,7 @@ static void oa_report_id_clear(struct i915_perf_stream *stream, u32 *report)
 static bool oa_report_ctx_invalid(struct i915_perf_stream *stream, void *report)
 {
 	return !(oa_report_id(stream, report) &
-	       stream->perf->gen8_valid_ctx_bit) &&
-	       GRAPHICS_VER(stream->perf->i915) <= 11;
+	       stream->perf->gen8_valid_ctx_bit);
 }
 
 static u64 oa_timestamp(struct i915_perf_stream *stream, void *report)
@@ -5047,6 +5046,7 @@ static void i915_perf_init_info(struct drm_i915_private *i915)
 		perf->gen8_valid_ctx_bit = BIT(16);
 		break;
 	case 12:
+		perf->gen8_valid_ctx_bit = BIT(16);
 		/*
 		 * Calculate offset at runtime in oa_pin_context for gen12 and
 		 * cache the value in perf->ctx_oactxctrl_offset.