[PATCH 2/2] drm/amdgpu: use xarray for storing pasid in vm
Christian König
ckoenig.leichtzumerken at gmail.com
Wed Jun 23 12:50:55 UTC 2021
Am 23.06.21 um 14:25 schrieb Nirmoy Das:
> Replace idr with xarray as we actually need hash functionality.
> Cleanup code related to vm pasid by adding helper function.
>
> Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 134 +++++++++++--------------
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h | 3 +-
> 2 files changed, 60 insertions(+), 77 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index be841d62a1d4..e047e56a4be2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -87,6 +87,39 @@ struct amdgpu_prt_cb {
> struct dma_fence_cb cb;
> };
>
> +static int amdgpu_vm_set_pasid(struct amdgpu_device *adev,
> + struct amdgpu_vm *vm,
> + unsigned long pasid)
Some kerneldoc please describing why we have that function.
> +{
> + unsigned long flags;
> + int r;
> +
> + if (pasid) {
You should probably reorder the code so that the old pasid is first
removed and then eventually the new one added.
> + 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);
As far as I can see this can just use xa_store() which also drops the
need for GFP_ATOMIC here.
> + if (r < 0)
> + return r;
> + } else {
> + unsigned long index;
> + struct amdgpu_vm *res;
> +
> + xa_lock_irqsave(&adev->vm_manager.pasids, flags);
> + xa_for_each(&adev->vm_manager.pasids, index, res) {
> + if (res == vm) {
> + __xa_erase(&adev->vm_manager.pasids, index);
> + break;
> + }
> + }
> + xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
That is really ugly, why is that necessary?
Christian
> + }
> +
> + vm->pasid = pasid;
> +
> + return 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 +2973,9 @@ 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_set_pasid(adev, vm, pasid);
> + if (r)
> + goto error_free_root;
>
> INIT_KFIFO(vm->faults);
>
> @@ -3039,18 +3063,11 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *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;
> - }
> + /* remove previous {pasid:vm} entry first */
> + r = amdgpu_vm_set_pasid(adev, vm, 0);
> + r = amdgpu_vm_set_pasid(adev, vm, pasid);
> + if (r)
> + goto unreserve_bo;
>
> /* Check if PD needs to be reinitialized and do it before
> * changing any other state, in case it fails.
> @@ -3061,7 +3078,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> to_amdgpu_bo_vm(vm->root.bo),
> false);
> if (r)
> - goto free_idr;
> + goto free_pasid_entry;
> }
>
> /* Update VM state */
> @@ -3078,7 +3095,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> r = amdgpu_bo_sync_wait(vm->root.bo,
> AMDGPU_FENCE_OWNER_UNDEFINED, true);
> if (r)
> - goto free_idr;
> + goto free_pasid_entry;
>
> vm->update_funcs = &amdgpu_vm_cpu_funcs;
> } else {
> @@ -3088,31 +3105,14 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
> vm->last_update = NULL;
> 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);
> - vm->pasid = 0;
> - }
> -
> /* 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;
> +free_pasid_entry:
> + amdgpu_vm_set_pasid(adev, vm, 0);
>
> - 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;
> @@ -3128,14 +3128,7 @@ 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_set_pasid(adev, vm, 0);
> vm->is_compute_context = false;
> }
>
> @@ -3159,15 +3152,7 @@ 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_set_pasid(adev, vm, 0);
> dma_fence_wait(vm->last_unlocked, false);
> dma_fence_put(vm->last_unlocked);
>
> @@ -3249,8 +3234,7 @@ 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);
> }
>
> /**
> @@ -3262,8 +3246,8 @@ 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);
> }
> @@ -3332,13 +3316,13 @@ 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);
> }
>
> /**
> @@ -3380,15 +3364,15 @@ 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;
> @@ -3406,11 +3390,11 @@ 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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