[PATCH 1/1] drm/amdgpu: cleanup pasid handling
Christian König
christian.koenig at amd.com
Wed Jun 23 08:23:58 UTC 2021
Am 23.06.21 um 09:56 schrieb Nirmoy Das:
> Cleanup code related to vm pasid by adding helper functions.
> Also replace idr with xarray as we actually need hash functionality.
That looks quite a bit better than before, but I think we should
approach it differently.
First of all make a patch which moves amdgpu_pasid_free() outside of the
VM code.
We don't allocate the pasid inside the VM code for good reasons so we
shouldn't free it either.
Then in a second patch make a function amdgpu_vm_set_pasid(adev, vm, pasid);
When the pasid is zero we remove the VM from the xarray, otherwise we
update the entry.
Thanks,
Christian.
>
> Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 130 ++++++++++++-------------
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 3 +-
> 2 files changed, 62 insertions(+), 71 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 63975bda8e76..abba1e2de264 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -87,6 +87,45 @@ struct amdgpu_prt_cb {
> struct dma_fence_cb cb;
> };
>
> +static int amdgpu_vm_pasid_insert(struct amdgpu_device *adev,
> + struct amdgpu_vm *vm,
> + unsigned long pasid,
> + unsigned int *vm_pasid)
> +{
> + unsigned long flags;
> + int r;
> +
> + if (!pasid)
> + return 0;
> +
> + xa_lock_irqsave(&adev->vm_manager.pasids, flags);
> + r = xa_err(__xa_store(&adev->vm_manager.pasids, pasid, vm, GFP_ATOMIC));
> + xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
> + if (r < 0)
> + return r;
> + if (vm_pasid)
> + *vm_pasid = pasid;
> +
> + return 0;
> +}
> +
> +static void amdgpu_vm_pasid_remove(struct amdgpu_device *adev,
> + unsigned long pasid,
> + unsigned int *vm_pasid)
> +{
> + unsigned long flags;
> +
> + if (!pasid)
> + return;
> +
> + xa_lock_irqsave(&adev->vm_manager.pasids, flags);
> + __xa_erase(&adev->vm_manager.pasids, pasid);
> + xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
> +
> + if (vm_pasid)
> + *vm_pasid = 0;
> +}
> +
> /*
> * vm eviction_lock can be taken in MMU notifiers. Make sure no reclaim-FS
> * happens while holding this lock anywhere to prevent deadlocks when
> @@ -2940,18 +2979,9 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm, u32 pasid)
>
> amdgpu_bo_unreserve(vm->root.bo);
>
> - if (pasid) {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> - r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
> - GFP_ATOMIC);
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> - if (r < 0)
> - goto error_free_root;
> -
> - vm->pasid = pasid;
> - }
> + r = amdgpu_vm_pasid_insert(adev, vm, pasid, &vm->pasid);
> + if (r)
> + goto error_free_root;
>
> INIT_KFIFO(vm->faults);
>
> @@ -3038,19 +3068,9 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> r = amdgpu_vm_check_clean_reserved(adev, vm);
> if (r)
> goto unreserve_bo;
> -
> - if (pasid) {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> - r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
> - GFP_ATOMIC);
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> -
> - if (r == -ENOSPC)
> - goto unreserve_bo;
> - r = 0;
> - }
> + r = amdgpu_vm_pasid_insert(adev, vm, pasid, NULL);
> + if (r)
> + goto unreserve_bo;
>
> /* Check if PD needs to be reinitialized and do it before
> * changing any other state, in case it fails.
> @@ -3089,35 +3109,23 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> vm->is_compute_context = true;
>
> if (vm->pasid) {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> - idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> -
> /* Free the original amdgpu allocated pasid
> * Will be replaced with kfd allocated pasid
> */
> amdgpu_pasid_free(vm->pasid);
> - vm->pasid = 0;
> + amdgpu_vm_pasid_remove(adev, vm->pasid, &vm->pasid);
> }
>
> /* Free the shadow bo for compute VM */
> amdgpu_bo_unref(&to_amdgpu_bo_vm(vm->root.bo)->shadow);
> -
> if (pasid)
> vm->pasid = pasid;
>
> goto unreserve_bo;
>
> free_idr:
> - if (pasid) {
> - unsigned long flags;
> + amdgpu_vm_pasid_remove(adev, pasid, NULL);
>
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> - idr_remove(&adev->vm_manager.pasid_idr, pasid);
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> - }
> unreserve_bo:
> amdgpu_bo_unreserve(vm->root.bo);
> return r;
> @@ -3133,14 +3141,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> */
> void amdgpu_vm_release_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
> {
> - if (vm->pasid) {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> - idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> - }
> - vm->pasid = 0;
> + amdgpu_vm_pasid_remove(adev, vm->pasid, &vm->pasid);
> vm->is_compute_context = false;
> }
>
> @@ -3164,15 +3165,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>
> root = amdgpu_bo_ref(vm->root.bo);
> amdgpu_bo_reserve(root, true);
> - if (vm->pasid) {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> - idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> - vm->pasid = 0;
> - }
> -
> + amdgpu_vm_pasid_remove(adev, vm->pasid, &vm->pasid);
> dma_fence_wait(vm->last_unlocked, false);
> dma_fence_put(vm->last_unlocked);
>
> @@ -3254,8 +3247,7 @@ void amdgpu_vm_manager_init(struct amdgpu_device *adev)
> adev->vm_manager.vm_update_mode = 0;
> #endif
>
> - idr_init(&adev->vm_manager.pasid_idr);
> - spin_lock_init(&adev->vm_manager.pasid_lock);
> + xa_init_flags(&adev->vm_manager.pasids, XA_FLAGS_LOCK_IRQ);
> }
>
> /**
> @@ -3267,8 +3259,8 @@ void amdgpu_vm_manager_init(struct amdgpu_device *adev)
> */
> void amdgpu_vm_manager_fini(struct amdgpu_device *adev)
> {
> - WARN_ON(!idr_is_empty(&adev->vm_manager.pasid_idr));
> - idr_destroy(&adev->vm_manager.pasid_idr);
> + WARN_ON(!xa_empty(&adev->vm_manager.pasids));
> + xa_destroy(&adev->vm_manager.pasids);
>
> amdgpu_vmid_mgr_fini(adev);
> }
> @@ -3337,13 +3329,13 @@ void amdgpu_vm_get_task_info(struct amdgpu_device *adev, u32 pasid,
> struct amdgpu_vm *vm;
> unsigned long flags;
>
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
> + xa_lock_irqsave(&adev->vm_manager.pasids, flags);
>
> - vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
> + vm = xa_load(&adev->vm_manager.pasids, pasid);
> if (vm)
> *task_info = vm->task_info;
>
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
> + xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
> }
>
> /**
> @@ -3385,15 +3377,15 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
> struct amdgpu_vm *vm;
> int r;
>
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, irqflags);
> - vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
> + xa_lock_irqsave(&adev->vm_manager.pasids, irqflags);
> + vm = xa_load(&adev->vm_manager.pasids, pasid);
> if (vm) {
> root = amdgpu_bo_ref(vm->root.bo);
> is_compute_context = vm->is_compute_context;
> } else {
> root = NULL;
> }
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, irqflags);
> + xa_unlock_irqrestore(&adev->vm_manager.pasids, irqflags);
>
> if (!root)
> return false;
> @@ -3411,11 +3403,11 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
> goto error_unref;
>
> /* Double check that the VM still exists */
> - spin_lock_irqsave(&adev->vm_manager.pasid_lock, irqflags);
> - vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
> + xa_lock_irqsave(&adev->vm_manager.pasids, irqflags);
> + vm = xa_load(&adev->vm_manager.pasids, pasid);
> if (vm && vm->root.bo != root)
> vm = NULL;
> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, irqflags);
> + xa_unlock_irqrestore(&adev->vm_manager.pasids, irqflags);
> if (!vm)
> goto error_unlock;
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index ddb85a85cbba..31c467764162 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -359,8 +359,7 @@ struct amdgpu_vm_manager {
> /* PASID to VM mapping, will be used in interrupt context to
> * look up VM of a page fault
> */
> - struct idr pasid_idr;
> - spinlock_t pasid_lock;
> + struct xarray pasids;
> };
>
> struct amdgpu_bo_va_mapping;
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