From: Alex Deucher Date: Mon, 16 Mar 2026 15:04:46 +0000 (-0400) Subject: drm/amdgpu: rework how we handle TLB fences X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=69c5fbd2b93b5ced77c6e79afe83371bca84c788;p=thirdparty%2Flinux.git drm/amdgpu: rework how we handle TLB fences Add a new VM flag to indicate whether or not we need a TLB fence. Userqs (KFD or KGD) require a TLB fence. A TLB fence is not strictly required for kernel queues, but it shouldn't hurt. That said, enabling this unconditionally should be fine, but it seems to tickle some issues in KIQ/MES. Only enable them for KFD, or when KGD userq queues are enabled (currently via module parameter). Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4798 Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4749 Fixes: f3854e04b708 ("drm/amdgpu: attach tlb fence to the PTs update") Cc: Christian König Cc: Prike Liang Reviewed-by: Prike Liang Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c index dcd49b0fb6e09..b7b06b0a83b18 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c @@ -1073,7 +1073,10 @@ amdgpu_vm_tlb_flush(struct amdgpu_vm_update_params *params, } /* Prepare a TLB flush fence to be attached to PTs */ - if (!params->unlocked) { + /* The check for need_tlb_fence should be dropped once we + * sort out the issues with KIQ/MES TLB invalidation timeouts. + */ + if (!params->unlocked && vm->need_tlb_fence) { amdgpu_vm_tlb_fence_create(params->adev, vm, fence); /* Makes sure no PD/PT is freed before the flush */ @@ -2606,6 +2609,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm, ttm_lru_bulk_move_init(&vm->lru_bulk_move); vm->is_compute_context = false; + vm->need_tlb_fence = amdgpu_userq_enabled(&adev->ddev); vm->use_cpu_for_update = !!(adev->vm_manager.vm_update_mode & AMDGPU_VM_USE_CPU_FOR_GFX); @@ -2743,6 +2747,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm) dma_fence_put(vm->last_update); vm->last_update = dma_fence_get_stub(); vm->is_compute_context = true; + vm->need_tlb_fence = true; unreserve_bo: amdgpu_bo_unreserve(vm->root.bo); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h index 46628b0e699bc..641fe91b4f035 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h @@ -441,6 +441,8 @@ struct amdgpu_vm { struct ttm_lru_bulk_move lru_bulk_move; /* Flag to indicate if VM is used for compute */ bool is_compute_context; + /* Flag to indicate if VM needs a TLB fence (KFD or KGD) */ + bool need_tlb_fence; /* Memory partition number, -1 means any partition */ int8_t mem_id;