drm/amdgpu:enable mcbp for gfx9(v2)

set bit 21 of IB.control filed to actually enable
MCBP for SRIOV
v2:
add flag for preemption enable bit for soc15 and use
this flag instead of hardcode.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
index 69fa156..f124f6d 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
@@ -3073,6 +3073,9 @@ static void gfx_v9_0_ring_emit_ib_gfx(struct amdgpu_ring *ring,
 
         control |= ib->length_dw | (vm_id << 24);
 
+		if (amdgpu_sriov_vf(ring->adev) && (ib->flags & AMDGPU_IB_FLAG_PREEMPT))
+			control |= INDIRECT_BUFFER_PRE_ENB(1);
+
         amdgpu_ring_write(ring, header);
 	BUG_ON(ib->gpu_addr & 0x3); /* Dword align */
         amdgpu_ring_write(ring,
diff --git a/drivers/gpu/drm/amd/amdgpu/soc15d.h b/drivers/gpu/drm/amd/amdgpu/soc15d.h
index 7d29329..75403c7 100644
--- a/drivers/gpu/drm/amd/amdgpu/soc15d.h
+++ b/drivers/gpu/drm/amd/amdgpu/soc15d.h
@@ -137,6 +137,7 @@
 		 * 1 - Stream
 		 * 2 - Bypass
 		 */
+#define     INDIRECT_BUFFER_PRE_ENB(x)		 ((x) << 21)
 #define	PACKET3_COPY_DATA				0x40
 #define	PACKET3_PFP_SYNC_ME				0x42
 #define	PACKET3_COND_WRITE				0x45