[RFC PATCH 1/8] drm/xe: Add xe_hw_engine_write_ring_tail

[Matthew Brost <matthew.brost@intel.com>]

ULLS for migration jobs need to directly set hw engine ring tail.

Signed-off-by: Matthew Brost <matthew.brost@intel.com
---
 drivers/gpu/drm/xe/xe_hw_engine.c | 10 ++++++++++
 drivers/gpu/drm/xe/xe_hw_engine.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
index 402dfa748e16..ee006b393e2f 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine.c
@@ -298,6 +298,16 @@ void xe_hw_engine_mmio_write32(struct xe_hw_engine *hwe,
 	xe_mmio_write32(hwe->gt, reg, val);
 }
 
+/**
+ * xe_hw_engine_write_ring_tail() - Write ring tail
+ * @hwe: engine
+ * @val: desired 32-bit value to write
+ */
+void xe_hw_engine_write_ring_tail(struct xe_hw_engine *hwe, u32 val)
+{
+	xe_hw_engine_mmio_write32(hwe, RING_TAIL(0), val);
+}
+
 /**
  * xe_hw_engine_mmio_read32() - Read engine register
  * @hwe: engine
diff --git a/drivers/gpu/drm/xe/xe_hw_engine.h b/drivers/gpu/drm/xe/xe_hw_engine.h
index 022819a4a8eb..076230b158b3 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.h
+++ b/drivers/gpu/drm/xe/xe_hw_engine.h
@@ -80,5 +80,6 @@ enum xe_force_wake_domains xe_hw_engine_to_fw_domain(struct xe_hw_engine *hwe);
 
 void xe_hw_engine_mmio_write32(struct xe_hw_engine *hwe, struct xe_reg reg, u32 val);
 u32 xe_hw_engine_mmio_read32(struct xe_hw_engine *hwe, struct xe_reg reg);
+void xe_hw_engine_write_ring_tail(struct xe_hw_engine *hwe, u32 val);
 
 #endif
-- 
2.34.1