drm/panfrost: Handle HW_ISSUE_TTRX_2968_TTRX_3162

Add handling for the HW_ISSUE_TTRX_2968_TTRX_3162 quirk. Logic ported
from kbase. kbase lists this workaround as used on Mali-G57.
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220525145754.25866-3-alyssa.rosenzweig@collabora.com

drivers/gpu/drm/panfrost/panfrost_gpu.c

@@ -108,6 +108,9 @@ static void panfrost_gpu_init_quirks(struct panfrost_device *pfdev)
 			quirks |= SC_LS_ALLOW_ATTR_TYPES;
 	}
 
+	if (panfrost_has_hw_issue(pfdev, HW_ISSUE_TTRX_2968_TTRX_3162))
+		quirks |= SC_VAR_ALGORITHM;
+
 	if (panfrost_has_hw_feature(pfdev, HW_FEATURE_TLS_HASHING))
 		quirks |= SC_TLS_HASH_ENABLE;
 

drivers/gpu/drm/panfrost/panfrost_issues.h

@@ -125,6 +125,9 @@ enum panfrost_hw_issue {
 	 * kernel must fiddle with L2 caches to prevent data leakage */
 	HW_ISSUE_TGOX_R1_1234,
 
+	/* Must set SC_VAR_ALGORITHM */
+	HW_ISSUE_TTRX_2968_TTRX_3162,
+
 	HW_ISSUE_END
 };
 

drivers/gpu/drm/panfrost/panfrost_regs.h

@@ -195,6 +195,7 @@
 #define SC_TLS_HASH_ENABLE		BIT(17)
 #define SC_LS_ATTR_CHECK_DISABLE	BIT(18)
 #define SC_ENABLE_TEXGRD_FLAGS		BIT(25)
+#define SC_VAR_ALGORITHM		BIT(29)
 /* End SHADER_CONFIG register */
 
 /* TILER_CONFIG register */