drm/radeon: fix PFP sync in vm_flush

Otherwise the next IB might start reading commands
with the page table still invalid.

Signed-off-by: Christian König <deathsimple@vodafone.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

3 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 8c74c729586d..19b7fe1248be 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -1586,4 +1586,8 @@ void cayman_vm_flush(struct radeon_device *rdev, int ridx, struct radeon_vm *vm)
         /* bits 0-7 are the VM contexts0-7 */
         radeon_ring_write(ring, PACKET0(VM_INVALIDATE_REQUEST, 0));
         radeon_ring_write(ring, 1 << vm->id);
+
+        /* sync PFP to ME, otherwise we might get invalid PFP reads */
+        radeon_ring_write(ring, PACKET3(PACKET3_PFP_SYNC_ME, 0));
+        radeon_ring_write(ring, 0x0);
 }
diff --git a/drivers/gpu/drm/radeon/nid.h b/drivers/gpu/drm/radeon/nid.h
index 2423d1b5d385..cbef6815907a 100644
--- a/drivers/gpu/drm/radeon/nid.h
+++ b/drivers/gpu/drm/radeon/nid.h
@@ -502,6 +502,7 @@
 #define PACKET3_MPEG_INDEX                              0x3A
 #define PACKET3_WAIT_REG_MEM                            0x3C
 #define PACKET3_MEM_WRITE                               0x3D
+#define PACKET3_PFP_SYNC_ME                             0x42
 #define PACKET3_SURFACE_SYNC                            0x43
 #              define PACKET3_CB0_DEST_BASE_ENA    (1 << 6)
 #              define PACKET3_CB1_DEST_BASE_ENA    (1 << 7)
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index df8dd7701643..da184de021bd 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -2868,6 +2868,10 @@ void si_vm_flush(struct radeon_device *rdev, int ridx, struct radeon_vm *vm)
         radeon_ring_write(ring, VM_INVALIDATE_REQUEST >> 2);
         radeon_ring_write(ring, 0);
         radeon_ring_write(ring, 1 << vm->id);
+
+        /* sync PFP to ME, otherwise we might get invalid PFP reads */
+        radeon_ring_write(ring, PACKET3(PACKET3_PFP_SYNC_ME, 0));
+        radeon_ring_write(ring, 0x0);
 }
 
 /*