[PATCH 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

v3:
- Initialize the engine group even if mc6 is enabled (Ashutosh)
- Checkpatch fix

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
---
 drivers/gpu/drm/i915/i915_perf.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 18afa76653b7..c035dbb84c9b 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"
 
@@ -4223,6 +4224,19 @@ 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->oa_group->type == TYPE_OAM &&
+	    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;
+	}
+
 	i = array_index_nospec(props->oa_format, I915_OA_FORMAT_MAX);
 	f = &perf->oa_formats[i];
 	if (!engine_supports_oa_format(props->engine, f->type)) {
@@ -5316,6 +5330,23 @@ 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