An indirect ctx wabb is implemented as per Wa_22011450934 to avoid rcs
restore hang during context restore of a preempted context in GPGPU mode
Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx>
cc: Chris Wilson <chris.p.wilson@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_lrc.c | 28 ++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 4 ++++
2 files changed, 32 insertions(+)
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 89a95a125fc8..8440f4b0f613 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1165,6 +1165,29 @@ gen12_emit_cmd_buf_wa(const struct intel_context *ce, u32 *cs)
return cs;
}
+/*
+ * On DG2 during context restore of a preempted context in GPGPU mode,
+ * RCS restore hang is detected. This is extremely timing dependent.
+ * To address this below sw wabb is implemented for DG2 A steppings.
+ */
+static u32 *
+dg2_emit_rcs_hang_wabb(const struct intel_context *ce, u32 *cs)
+{
+ *cs++ = MI_LOAD_REGISTER_IMM(1);
+ *cs++ = i915_mmio_reg_offset(GEN12_STATE_ACK_DEBUG);
+ *cs++ = 0x21;
+
+ *cs++ = MI_LOAD_REGISTER_REG;
+ *cs++ = i915_mmio_reg_offset(RING_NOPID(ce->engine->mmio_base));
+ *cs++ = i915_mmio_reg_offset(GEN12_CULLBIT1);
+
+ *cs++ = MI_LOAD_REGISTER_REG;
+ *cs++ = i915_mmio_reg_offset(RING_NOPID(ce->engine->mmio_base));
+ *cs++ = i915_mmio_reg_offset(GEN12_CULLBIT2);
+
+ return cs;
+}
+
static u32 *
gen12_emit_indirect_ctx_rcs(const struct intel_context *ce, u32 *cs)
{
@@ -1172,6 +1195,11 @@ gen12_emit_indirect_ctx_rcs(const struct intel_context *ce, u32 *cs)
cs = gen12_emit_cmd_buf_wa(ce, cs);
cs = gen12_emit_restore_scratch(ce, cs);
+ /* Wa_22011450934:dg2 */
+ if (IS_DG2_GRAPHICS_STEP(ce->engine->i915, G10, STEP_A0, STEP_B0) ||
+ IS_DG2_GRAPHICS_STEP(ce->engine->i915, G11, STEP_A0, STEP_B0))
+ cs = dg2_emit_rcs_hang_wabb(ce, cs);
+
/* Wa_16013000631:dg2 */
if (IS_DG2_GRAPHICS_STEP(ce->engine->i915, G10, STEP_B0, STEP_C0) ||
IS_DG2_G11(ce->engine->i915))
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ec48406eb37a..3f94f4b5ef6c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -12026,4 +12026,8 @@ enum skl_power_gate {
#define SLICE_COMMON_ECO_CHICKEN1 _MMIO(0x731C)
#define MSC_MSAA_REODER_BUF_BYPASS_DISABLE REG_BIT(14)
+#define GEN12_CULLBIT1 _MMIO(0x6100)
+#define GEN12_CULLBIT2 _MMIO(0x7030)
+#define GEN12_STATE_ACK_DEBUG _MMIO(0x20BC)
+
#endif /* _I915_REG_H_ */
--
2.20.1
