Series is:
Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
On Mon, Dec 5, 2022 at 5:43 AM Christian König
<ckoenig.leichtzumerken@xxxxxxxxx> wrote:
>
> Instead of reserving a VMID for a single process allow that many
> processes use the reserved ID. This allows for proper isolation
> between the processes.
>
> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c | 45 ++++++++++++-------------
> drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h | 3 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 6 +---
> 3 files changed, 24 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> index 7e5aad241295..6481b43ffe25 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
> @@ -279,12 +279,13 @@ static int amdgpu_vmid_grab_reserved(struct amdgpu_vm *vm,
> {
> struct amdgpu_device *adev = ring->adev;
> unsigned vmhub = ring->funcs->vmhub;
> + struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
> uint64_t fence_context = adev->fence_context + ring->idx;
> bool needs_flush = vm->use_cpu_for_update;
> uint64_t updates = amdgpu_vm_tlb_seq(vm);
> int r;
>
> - *id = vm->reserved_vmid[vmhub];
> + *id = id_mgr->reserved;
> if ((*id)->owner != vm->immediate.fence_context ||
> !amdgpu_vmid_compatible(*id, job) ||
> (*id)->flushed_updates < updates ||
> @@ -464,31 +465,27 @@ int amdgpu_vmid_alloc_reserved(struct amdgpu_device *adev,
> struct amdgpu_vm *vm,
> unsigned vmhub)
> {
> - struct amdgpu_vmid_mgr *id_mgr;
> - struct amdgpu_vmid *idle;
> - int r = 0;
> + struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
>
> - id_mgr = &adev->vm_manager.id_mgr[vmhub];
> mutex_lock(&id_mgr->lock);
> if (vm->reserved_vmid[vmhub])
> goto unlock;
> - if (atomic_inc_return(&id_mgr->reserved_vmid_num) >
> - AMDGPU_VM_MAX_RESERVED_VMID) {
> - DRM_ERROR("Over limitation of reserved vmid\n");
> - atomic_dec(&id_mgr->reserved_vmid_num);
> - r = -EINVAL;
> - goto unlock;
> +
> + ++id_mgr->reserved_use_count;
> + if (!id_mgr->reserved) {
> + struct amdgpu_vmid *id;
> +
> + id = list_first_entry(&id_mgr->ids_lru, struct amdgpu_vmid,
> + list);
> + /* Remove from normal round robin handling */
> + list_del_init(&id->list);
> + id_mgr->reserved = id;
> }
> - /* Select the first entry VMID */
> - idle = list_first_entry(&id_mgr->ids_lru, struct amdgpu_vmid, list);
> - list_del_init(&idle->list);
> - vm->reserved_vmid[vmhub] = idle;
> - mutex_unlock(&id_mgr->lock);
> + vm->reserved_vmid[vmhub] = true;
>
> - return 0;
> unlock:
> mutex_unlock(&id_mgr->lock);
> - return r;
> + return 0;
> }
>
> void amdgpu_vmid_free_reserved(struct amdgpu_device *adev,
> @@ -498,12 +495,12 @@ void amdgpu_vmid_free_reserved(struct amdgpu_device *adev,
> struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
>
> mutex_lock(&id_mgr->lock);
> - if (vm->reserved_vmid[vmhub]) {
> - list_add(&vm->reserved_vmid[vmhub]->list,
> - &id_mgr->ids_lru);
> - vm->reserved_vmid[vmhub] = NULL;
> - atomic_dec(&id_mgr->reserved_vmid_num);
> + if (vm->reserved_vmid[vmhub] &&
> + !--id_mgr->reserved_use_count) {
> + /* give the reserved ID back to normal round robin */
> + list_add(&id_mgr->reserved->list, &id_mgr->ids_lru);
> }
> + vm->reserved_vmid[vmhub] = false;
> mutex_unlock(&id_mgr->lock);
> }
>
> @@ -570,7 +567,7 @@ void amdgpu_vmid_mgr_init(struct amdgpu_device *adev)
>
> mutex_init(&id_mgr->lock);
> INIT_LIST_HEAD(&id_mgr->ids_lru);
> - atomic_set(&id_mgr->reserved_vmid_num, 0);
> + id_mgr->reserved_use_count = 0;
>
> /* manage only VMIDs not used by KFD */
> id_mgr->num_ids = adev->vm_manager.first_kfd_vmid;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h
> index 06c8a0034fa5..c573a8ffff47 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.h
> @@ -67,7 +67,8 @@ struct amdgpu_vmid_mgr {
> unsigned num_ids;
> struct list_head ids_lru;
> struct amdgpu_vmid ids[AMDGPU_NUM_VMID];
> - atomic_t reserved_vmid_num;
> + struct amdgpu_vmid *reserved;
> + unsigned int reserved_use_count;
> };
>
> int amdgpu_pasid_alloc(unsigned int bits);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index 6546e786bf00..094bb4807303 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -119,9 +119,6 @@ struct amdgpu_bo_vm;
> /* Reserve 2MB at top/bottom of address space for kernel use */
> #define AMDGPU_VA_RESERVED_SIZE (2ULL << 20)
>
> -/* max vmids dedicated for process */
> -#define AMDGPU_VM_MAX_RESERVED_VMID 1
> -
> /* See vm_update_mode */
> #define AMDGPU_VM_USE_CPU_FOR_GFX (1 << 0)
> #define AMDGPU_VM_USE_CPU_FOR_COMPUTE (1 << 1)
> @@ -298,8 +295,7 @@ struct amdgpu_vm {
> struct dma_fence *last_unlocked;
>
> unsigned int pasid;
> - /* dedicated to vm */
> - struct amdgpu_vmid *reserved_vmid[AMDGPU_MAX_VMHUBS];
> + bool reserved_vmid[AMDGPU_MAX_VMHUBS];
>
> /* Flag to indicate if VM tables are updated by CPU or GPU (SDMA) */
> bool use_cpu_for_update;
> --
> 2.34.1
>
