From acfb5554c769ad7e09b9e4e42b572cc297a728e9 Mon Sep 17 00:00:00 2001
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Date: Wed, 23 Aug 2017 13:35:04 -0700
Subject: [PATCH] drm/i915/cnl: WaForceContextSaveRestoreNonCoherent
Git-commit: acfb5554c769ad7e09b9e4e42b572cc297a728e9
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900
To avoid a potential hang condition with TLB invalidation
we need to enable masked bit 5 of MMIO 0xE5F0 at boot.
Same workaround was in place for previous platforms,
but the register offset has changed for CNL.
But also BSpec doesn't mention the bit 15 as set on gen9
platforms and mark bit as reserved on CNL.
V2: Improve commit message accepting Oscar's suggestion.
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Oscar Mateo <oscar.mateo@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170823203504.10012-1-rodrigo.vivi@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_reg.h | 1 +
drivers/gpu/drm/i915/intel_engine_cs.c | 4 ++++
2 files changed, 5 insertions(+)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7025,6 +7025,7 @@ enum {
/* GEN8 chicken */
#define HDC_CHICKEN0 _MMIO(0x7300)
+#define CNL_HDC_CHICKEN0 _MMIO(0xE5F0)
#define HDC_FORCE_CSR_NON_COHERENT_OVR_DISABLE (1<<15)
#define HDC_FENCE_DEST_SLM_DISABLE (1<<14)
#define HDC_DONOT_FETCH_MEM_WHEN_MASKED (1<<11)
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1073,6 +1073,10 @@ static int cnl_init_workarounds(struct i
struct drm_i915_private *dev_priv = engine->i915;
int ret;
+ /* WaForceContextSaveRestoreNonCoherent:cnl */
+ WA_SET_BIT_MASKED(CNL_HDC_CHICKEN0,
+ HDC_FORCE_CONTEXT_SAVE_RESTORE_NON_COHERENT);
+
/* WaDisableReplayBufferBankArbitrationOptimization:cnl */
WA_SET_BIT_MASKED(COMMON_SLICE_CHICKEN2,
GEN8_SBE_DISABLE_REPLAY_BUF_OPTIMIZATION);