[Intel-gfx] [PATCH 4/4] drm/i915/gen12: Invalidate aux table entries forcibly

[Mika Kuoppala]

Aux table invalidation can fail on update. So
next access may cause memory access to be into stale entry.

Proposed workaround is to invalidate entries between
all batchbuffers.

v2: correct register address (Yang)

References bspec#43904, hsdes#1809175790
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Chuansheng Liu <chuansheng.liu at intel.com>
Cc: Rafael Antognolli <rafael.antognolli at intel.com>
Cc: Yang A Shi <yang.a.shi at intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 16 +++++++++++++++-
 drivers/gpu/drm/i915/i915_reg.h     |  2 ++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index e1235d504837..bbdb0e2a4571 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -4539,6 +4539,17 @@ static u32 preparser_disable(bool state)
 	return MI_ARB_CHECK | 1 << 8 | state;
 }
 
+static u32 *
+gen12_emit_aux_table_inv(struct i915_request *rq, u32 *cs)
+{
+	*cs++ = MI_LOAD_REGISTER_IMM(1);
+	*cs++ = i915_mmio_reg_offset(GEN12_GFX_CCS_AUX_NV);
+	*cs++ = AUX_INV;
+	*cs++ = MI_NOOP;
+
+	return cs;
+}
+
 static int gen12_emit_flush_render(struct i915_request *request,
 				   u32 mode)
 {
@@ -4587,7 +4598,7 @@ static int gen12_emit_flush_render(struct i915_request *request,
 
 		flags |= PIPE_CONTROL_CS_STALL;
 
-		cs = intel_ring_begin(request, 8);
+		cs = intel_ring_begin(request, 8 + 4);
 		if (IS_ERR(cs))
 			return PTR_ERR(cs);
 
@@ -4600,6 +4611,9 @@ static int gen12_emit_flush_render(struct i915_request *request,
 
 		cs = gen8_emit_pipe_control(cs, flags, LRC_PPHWSP_SCRATCH_ADDR);
 
+		/* hsdes: 1809175790 */
+		cs = gen12_emit_aux_table_inv(request, cs);
+
 		*cs++ = preparser_disable(false);
 		intel_ring_advance(request, cs);
 	}
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index fde54b86ea20..5168cde0596f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2526,6 +2526,8 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define HSW_GTT_CACHE_EN	_MMIO(0x4024)
 #define   GTT_CACHE_EN_ALL	0xF0007FFF
 #define GEN7_WR_WATERMARK	_MMIO(0x4028)
+#define GEN12_GFX_CCS_AUX_NV	_MMIO(0x4208)
+#define   AUX_INV		REG_BIT(0)
 #define GEN7_GFX_PRIO_CTRL	_MMIO(0x402C)
 #define ARB_MODE		_MMIO(0x4030)
 #define   ARB_MODE_SWIZZLE_SNB	(1 << 4)
-- 
2.17.1