drm/radeon: Allow setting shader registers using DMA/COPY packet3 on SI.

Mesa uses a COPY_DATA packet to copy the grid size for indirect dispatches
into COMPUTE_USER_DATA_*.

Setting those registers with a SET_SH_REG packet is allowed, not allowing
them with other packets seems like an oversight.

v2: Clarify commit message.
Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_drv.c

@@ -94,9 +94,10 @@
  *   2.42.0 - Add VCE/VUI (Video Usability Information) support
  *   2.43.0 - RADEON_INFO_GPU_RESET_COUNTER
  *   2.44.0 - SET_APPEND_CNT packet3 support
+ *   2.45.0 - Allow setting shader registers using DMA/COPY packet3 on SI
  */
 #define KMS_DRIVER_MAJOR	2
-#define KMS_DRIVER_MINOR	44
+#define KMS_DRIVER_MINOR	45
 #define KMS_DRIVER_PATCHLEVEL	0
 int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags);
 int radeon_driver_unload_kms(struct drm_device *dev);

drivers/gpu/drm/radeon/si.c

@@ -4364,6 +4364,10 @@ static bool si_vm_reg_valid(u32 reg)
 	if (reg >= 0x28000)
 		return true;
 
+	/* shader regs are also fine */
+	if (reg >= 0xB000 && reg < 0xC000)
+		return true;
+
 	/* check config regs */
 	switch (reg) {
 	case GRBM_GFX_INDEX: