[PATCH v7 11/11] drm/i915/perf: Wa_14017512683: Disable OAM if media C6 is enabled in BIOS

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>]

OAM does not work with media C6 enabled on some steppings of MTL.
Disable OAM if we detect that media C6 was enabled in bios.

v2: (Ashutosh)
- Remove drm_notice from the driver load path
- Log a drm_err when opening an OAM stream on affected steppings

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
---
 drivers/gpu/drm/i915/i915_perf.c | 41 ++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 18afa76653b7..823379d63caf 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -209,6 +209,7 @@
 #include "gt/intel_gt_regs.h"
 #include "gt/intel_lrc.h"
 #include "gt/intel_lrc_reg.h"
+#include "gt/intel_rc6.h"
 #include "gt/intel_ring.h"
 #include "gt/uc/intel_guc_slpc.h"
 
@@ -4216,6 +4217,20 @@ static int read_properties_unlocked(struct i915_perf *perf,
 		return -EINVAL;
 	}
 
+	/*
+	 * Wa_14017512683: mtl[a0..c0): Use of OAM must be preceded with Media
+	 * C6 disable in BIOS. Fail if Media C6 is enabled on steppings where OAM
+	 * does not work as expected.
+	 */
+	if (IS_MTL_MEDIA_STEP(props->engine->i915, STEP_A0, STEP_C0) &&
+	    props->engine->gt->type == GT_MEDIA &&
+	    intel_check_bios_c6_setup(&props->engine->gt->rc6)) {
+		drm_dbg(&perf->i915->drm,
+			"OAM requires media C6 to be disabled in BIOS\n");
+		return -EINVAL;
+	}
+
+
 	if (!engine_supports_oa(props->engine)) {
 		drm_dbg(&perf->i915->drm,
 			"Engine not supported by OA %d:%d\n",
@@ -4897,6 +4912,15 @@ static u32 num_perf_groups_per_gt(struct intel_gt *gt)
 
 static u32 __oam_engine_group(struct intel_engine_cs *engine)
 {
+	/*
+	 * Wa_14017512683: mtl[a0..c0): Use of OAM must be preceded with Media
+	 * C6 disable in BIOS. To disable use of OAM with media engines, set the
+	 * oa_group to PERF_GROUP_INVALID.
+	 */
+	if (IS_MTL_MEDIA_STEP(engine->i915, STEP_A0, STEP_C0) &&
+	    intel_check_bios_c6_setup(&engine->gt->rc6))
+		return PERF_GROUP_INVALID;
+
 	if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 70)) {
 		/*
 		 * There's 1 SAMEDIA gt and 1 OAM per SAMEDIA gt. All media slices
@@ -5316,6 +5340,23 @@ int i915_perf_ioctl_version(struct drm_i915_private *i915)
 	 *
 	 * 7: Add support for video decode and enhancement classes.
 	 */
+
+	/*
+	 * Wa_14017512683: mtl[a0..c0): Use of OAM must be preceded with Media
+	 * C6 disable in BIOS. If Media C6 is enabled in BIOS, return version 6
+	 * to indicate that OA media is not supported.
+	 */
+	if (IS_MTL_MEDIA_STEP(i915, STEP_A0, STEP_C0)) {
+		struct intel_gt *gt;
+		int i;
+
+		for_each_gt(gt, i915, i) {
+			if (gt->type == GT_MEDIA &&
+			    intel_check_bios_c6_setup(&gt->rc6))
+				return 6;
+		}
+	}
+
 	return 7;
 }
 
-- 
2.36.1