drm/amdgpu: fix colliding of preemption

what:
some os preemption path is messed up with world switch preemption

fix:
cleanup those logics so os preemption not mixed with world switch

this patch is a general fix for issues comes from SRIOV MCBP, but
there is still UMD side issues not resovlved yet, so this patch
cannot fix all world switch bug.
Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c

@@ -70,7 +70,8 @@ uint64_t amdgpu_sdma_get_csa_mc_addr(struct amdgpu_ring *ring,
 	uint32_t index = 0;
 	int r;
 
-	if (vmid == 0 || !amdgpu_mcbp)
+	/* don't enable OS preemption on SDMA under SRIOV */
+	if (amdgpu_sriov_vf(adev) || vmid == 0 || !amdgpu_mcbp)
 		return 0;
 
 	r = amdgpu_sdma_get_index_from_ring(ring, &index);

drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

@@ -4413,7 +4413,7 @@ static void gfx_v10_0_ring_emit_ib_gfx(struct amdgpu_ring *ring,
 
 	control |= ib->length_dw | (vmid << 24);
 
-	if (amdgpu_mcbp && (ib->flags & AMDGPU_IB_FLAG_PREEMPT)) {
+	if ((amdgpu_sriov_vf(ring->adev) || amdgpu_mcbp) && (ib->flags & AMDGPU_IB_FLAG_PREEMPT)) {
 		control |= INDIRECT_BUFFER_PRE_ENB(1);
 
 		if (flags & AMDGPU_IB_PREEMPTED)
@@ -4421,7 +4421,7 @@ static void gfx_v10_0_ring_emit_ib_gfx(struct amdgpu_ring *ring,
 
 		if (!(ib->flags & AMDGPU_IB_FLAG_CE))
 			gfx_v10_0_ring_emit_de_meta(ring,
-				    flags & AMDGPU_IB_PREEMPTED ? true : false);
+				    (!amdgpu_sriov_vf(ring->adev) && flags & AMDGPU_IB_PREEMPTED) ? true : false);
 	}
 
 	amdgpu_ring_write(ring, header);
@@ -4568,9 +4568,9 @@ static void gfx_v10_0_ring_emit_cntxcntl(struct amdgpu_ring *ring, uint32_t flag
 {
 	uint32_t dw2 = 0;
 
-	if (amdgpu_mcbp)
+	if (amdgpu_mcbp || amdgpu_sriov_vf(ring->adev))
 		gfx_v10_0_ring_emit_ce_meta(ring,
-				    flags & AMDGPU_IB_PREEMPTED ? true : false);
+				    (!amdgpu_sriov_vf(ring->adev) && flags & AMDGPU_IB_PREEMPTED) ? true : false);
 
 	gfx_v10_0_ring_emit_tmz(ring, true);