drm/xe/lnl: Enable GuC Wa_14019882105

Enable GuC Wa_14019882105 to block interrupts during C6 flow
when the memory path has been blocked

v2: Make helper function generic and name it as
    guc_waklv_enable_simple (John Harrison)
v3: Make warning descriptive (John Harrison)
v4: s/drm_WARN/xe_gt_WARN/ (Michal)

Cc: John Harrison <john.harrison@intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240405084231.3620848-3-badal.nilawar@intel.com

drivers/gpu/drm/xe/abi/guc_klvs_abi.h

@@ -319,4 +319,11 @@ enum  {
 #define GUC_KLV_VF_CFG_BEGIN_CONTEXT_ID_KEY	0x8a0b
 #define GUC_KLV_VF_CFG_BEGIN_CONTEXT_ID_LEN	1u
 
+/*
+ * Workaround keys:
+ */
+enum xe_guc_klv_ids {
+	GUC_WORKAROUND_KLV_BLOCK_INTERRUPTS_WHEN_MGSR_BLOCKED				= 0x9002,
+};
+
 #endif

drivers/gpu/drm/xe/xe_guc_ads.c

@@ -7,6 +7,8 @@
 
 #include <drm/drm_managed.h>
 
+#include <generated/xe_wa_oob.h>
+
 #include "regs/xe_engine_regs.h"
 #include "regs/xe_gt_regs.h"
 #include "regs/xe_guc_regs.h"
@@ -19,6 +21,7 @@
 #include "xe_map.h"
 #include "xe_mmio.h"
 #include "xe_platform_types.h"
+#include "xe_wa.h"
 
 /* Slack of a few additional entries per engine */
 #define ADS_REGSET_EXTRA_MAX	8
@@ -279,21 +282,42 @@ static size_t calculate_golden_lrc_size(struct xe_guc_ads *ads)
 	return total_size;
 }
 
+static void guc_waklv_enable_simple(struct xe_guc_ads *ads,
+				    enum xe_guc_klv_ids klv_id, u32 *offset, u32 *remain)
+{
+	u32 klv_entry[] = {
+		/* 16:16 key/length */
+		FIELD_PREP(GUC_KLV_0_KEY, klv_id) |
+		FIELD_PREP(GUC_KLV_0_LEN, 0),
+		/* 0 dwords data */
+	};
+	u32 size;
+
+	size = sizeof(klv_entry);
+
+	if (xe_gt_WARN(ads_to_gt(ads), *remain < size,
+		       "w/a klv buffer too small to add klv id %d\n", klv_id))
+		return;
+
+	xe_map_memcpy_to(ads_to_xe(ads), ads_to_map(ads), *offset,
+			 klv_entry, size);
+	*offset += size;
+	*remain -= size;
+}
+
 static void guc_waklv_init(struct xe_guc_ads *ads)
 {
+	struct xe_gt *gt = ads_to_gt(ads);
 	u64 addr_ggtt;
 	u32 offset, remain, size;
 
 	offset = guc_ads_waklv_offset(ads);
 	remain = guc_ads_waklv_size(ads);
 
-	/* Add workarounds here
-	 *
-	 * if (XE_WA(gt, wa_id))
-	 *	guc_waklv_enable_simple(ads,
-	 *				wa_klv_id,
-	 *				&offset, &remain);
-	 */
+	if (XE_WA(gt, 14019882105))
+		guc_waklv_enable_simple(ads,
+					GUC_WORKAROUND_KLV_BLOCK_INTERRUPTS_WHEN_MGSR_BLOCKED,
+					&offset, &remain);
 
 	size = guc_ads_waklv_size(ads) - remain;
 	if (!size)

drivers/gpu/drm/xe/xe_wa_oob.rules

@@ -20,3 +20,4 @@
 		MEDIA_VERSION(1300)
 		PLATFORM(DG2)
 14018094691	GRAPHICS_VERSION(2004)
+14019882105	GRAPHICS_VERSION(2004), GRAPHICS_STEP(A0, B0)