drm/amdgpu: fix GDS/GWS/OA switch handling

Bas pointed out that this isn't working as expected and could cause
crashes. Fix the handling by storing the marker that a switch is needed
inside the job instead.
Reported-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -165,6 +165,26 @@ bool amdgpu_vmid_had_gpu_reset(struct amdgpu_device *adev,
 		atomic_read(&adev->gpu_reset_counter);
 }
 
+/* Check if we need to switch to another set of resources */
+static bool amdgpu_vmid_gds_switch_needed(struct amdgpu_vmid *id,
+					  struct amdgpu_job *job)
+{
+	return id->gds_base != job->gds_base ||
+		id->gds_size != job->gds_size ||
+		id->gws_base != job->gws_base ||
+		id->gws_size != job->gws_size ||
+		id->oa_base != job->oa_base ||
+		id->oa_size != job->oa_size;
+}
+
+/* Check if the id is compatible with the job */
+static bool amdgpu_vmid_compatible(struct amdgpu_vmid *id,
+				   struct amdgpu_job *job)
+{
+	return  id->pd_gpu_addr == job->vm_pd_addr &&
+		!amdgpu_vmid_gds_switch_needed(id, job);
+}
+
 /**
  * amdgpu_vmid_grab_idle - grab idle VMID
  *
@@ -265,7 +285,7 @@ static int amdgpu_vmid_grab_reserved(struct amdgpu_vm *vm,
 
 	*id = vm->reserved_vmid[vmhub];
 	if ((*id)->owner != vm->immediate.fence_context ||
-	    (*id)->pd_gpu_addr != job->vm_pd_addr ||
+	    !amdgpu_vmid_compatible(*id, job) ||
 	    (*id)->flushed_updates < updates ||
 	    !(*id)->last_flush ||
 	    ((*id)->last_flush->context != fence_context &&
@@ -294,7 +314,6 @@ static int amdgpu_vmid_grab_reserved(struct amdgpu_vm *vm,
 	if (r)
 		return r;
 
-	(*id)->flushed_updates = updates;
 	job->vm_needs_flush = needs_flush;
 	return 0;
 }
@@ -333,7 +352,7 @@ static int amdgpu_vmid_grab_used(struct amdgpu_vm *vm,
 		if ((*id)->owner != vm->immediate.fence_context)
 			continue;
 
-		if ((*id)->pd_gpu_addr != job->vm_pd_addr)
+		if (!amdgpu_vmid_compatible(*id, job))
 			continue;
 
 		if (!(*id)->last_flush ||
@@ -355,7 +374,6 @@ static int amdgpu_vmid_grab_used(struct amdgpu_vm *vm,
 		if (r)
 			return r;
 
-		(*id)->flushed_updates = updates;
 		job->vm_needs_flush |= needs_flush;
 		return 0;
 	}
@@ -408,22 +426,30 @@ int amdgpu_vmid_grab(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
 			if (r)
 				goto error;
 
-			id->flushed_updates = amdgpu_vm_tlb_seq(vm);
 			job->vm_needs_flush = true;
 		}
 
 		list_move_tail(&id->list, &id_mgr->ids_lru);
 	}
 
-	id->pd_gpu_addr = job->vm_pd_addr;
-	id->owner = vm->immediate.fence_context;
-
+	job->gds_switch_needed = amdgpu_vmid_gds_switch_needed(id, job);
 	if (job->vm_needs_flush) {
+		id->flushed_updates = amdgpu_vm_tlb_seq(vm);
 		dma_fence_put(id->last_flush);
 		id->last_flush = NULL;
 	}
 	job->vmid = id - id_mgr->ids;
 	job->pasid = vm->pasid;
+
+	id->gds_base = job->gds_base;
+	id->gds_size = job->gds_size;
+	id->gws_base = job->gws_base;
+	id->gws_size = job->gws_size;
+	id->oa_base = job->oa_base;
+	id->oa_size = job->oa_size;
+	id->pd_gpu_addr = job->vm_pd_addr;
+	id->owner = vm->immediate.fence_context;
+
 	trace_amdgpu_vm_grab_id(vm, ring, job);
 
 error:

drivers/gpu/drm/amd/amdgpu/amdgpu_job.h

@@ -53,6 +53,7 @@ struct amdgpu_job {
 	uint32_t		preamble_status;
 	uint32_t                preemption_status;
 	bool                    vm_needs_flush;
+	bool			gds_switch_needed;
 	uint64_t		vm_pd_addr;
 	unsigned		vmid;
 	unsigned		pasid;

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

@@ -484,25 +484,20 @@ bool amdgpu_vm_need_pipeline_sync(struct amdgpu_ring *ring,
 	struct amdgpu_device *adev = ring->adev;
 	unsigned vmhub = ring->funcs->vmhub;
 	struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
-	struct amdgpu_vmid *id;
-	bool gds_switch_needed;
-	bool vm_flush_needed = job->vm_needs_flush || ring->has_compute_vm_bug;
 
 	if (job->vmid == 0)
 		return false;
-	id = &id_mgr->ids[job->vmid];
-	gds_switch_needed = ring->funcs->emit_gds_switch && (
-		id->gds_base != job->gds_base ||
-		id->gds_size != job->gds_size ||
-		id->gws_base != job->gws_base ||
-		id->gws_size != job->gws_size ||
-		id->oa_base != job->oa_base ||
-		id->oa_size != job->oa_size);
-
-	if (amdgpu_vmid_had_gpu_reset(adev, id))
+
+	if (job->vm_needs_flush || ring->has_compute_vm_bug)
+		return true;
+
+	if (ring->funcs->emit_gds_switch && job->gds_switch_needed)
 		return true;
 
-	return vm_flush_needed || gds_switch_needed;
+	if (amdgpu_vmid_had_gpu_reset(adev, &id_mgr->ids[job->vmid]))
+		return true;
+
+	return false;
 }
 
 /**
@@ -524,13 +519,8 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
 	unsigned vmhub = ring->funcs->vmhub;
 	struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
 	struct amdgpu_vmid *id = &id_mgr->ids[job->vmid];
-	bool gds_switch_needed = ring->funcs->emit_gds_switch && (
-		id->gds_base != job->gds_base ||
-		id->gds_size != job->gds_size ||
-		id->gws_base != job->gws_base ||
-		id->gws_size != job->gws_size ||
-		id->oa_base != job->oa_base ||
-		id->oa_size != job->oa_size);
+	bool gds_switch_needed = ring->funcs->emit_gds_switch &&
+		job->gds_switch_needed;
 	bool vm_flush_needed = job->vm_needs_flush;
 	struct dma_fence *fence = NULL;
 	bool pasid_mapping_needed = false;
@@ -577,6 +567,14 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
 	if (pasid_mapping_needed)
 		amdgpu_gmc_emit_pasid_mapping(ring, job->vmid, job->pasid);
 
+	if (!ring->is_mes_queue && ring->funcs->emit_gds_switch &&
+	    gds_switch_needed) {
+		amdgpu_ring_emit_gds_switch(ring, job->vmid, job->gds_base,
+					    job->gds_size, job->gws_base,
+					    job->gws_size, job->oa_base,
+					    job->oa_size);
+	}
+
 	if (vm_flush_needed || pasid_mapping_needed) {
 		r = amdgpu_fence_emit(ring, &fence, NULL, 0);
 		if (r)
@@ -601,20 +599,6 @@ int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job,
 	}
 	dma_fence_put(fence);
 
-	if (!ring->is_mes_queue && ring->funcs->emit_gds_switch &&
-	    gds_switch_needed) {
-		id->gds_base = job->gds_base;
-		id->gds_size = job->gds_size;
-		id->gws_base = job->gws_base;
-		id->gws_size = job->gws_size;
-		id->oa_base = job->oa_base;
-		id->oa_size = job->oa_size;
-		amdgpu_ring_emit_gds_switch(ring, job->vmid, job->gds_base,
-					    job->gds_size, job->gws_base,
-					    job->gws_size, job->oa_base,
-					    job->oa_size);
-	}
-
 	if (ring->funcs->patch_cond_exec)
 		amdgpu_ring_patch_cond_exec(ring, patch_offset);