Re: [PATCH 1/1] drm/amdgpu: add helper function for vm pasid

["Das, Nirmoy" <nirmoy.das@amd.com>]

On 6/21/2021 12:59 PM, Christian König wrote:
> Am 21.06.21 um 12:56 schrieb Das, Nirmoy:
>>
>> On 6/21/2021 12:26 PM, Christian König wrote:
>>> Well you completely break the handling in amdgpu_vm_handle_fault() 
>>> with this.
>>
>>
>> I see one issue with:  if (!vm || (vm && vm->root.bo != root)) . I 
>> will split it and resend.
>>
>> Am I missing something else ?
>
> The problem is you drop and re-take the lock now at the wrong time.


The original code is also dropping and retaking the lock.  I don't 
understand the difference.


Regards,

Nirmoy

>
> I don't think what you try to do here is possible at all.
>
> Christian.
>
>>
>>
>> Regards,
>>
>> Nirmoy
>>
>>
>>
>>>
>>> Christian.
>>>
>>> Am 21.06.21 um 11:47 schrieb Das, Nirmoy:
>>>> ping.
>>>>
>>>> On 6/17/2021 3:03 PM, Nirmoy Das wrote:
>>>>> Cleanup code related to vm pasid by adding helper function.
>>>>> This reduces lots code duplication.
>>>>>
>>>>> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
>>>>> ---
>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c |  17 +--
>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c  | 176 
>>>>> ++++++++++++------------
>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h  |   2 +-
>>>>>   3 files changed, 96 insertions(+), 99 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c 
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>>> index cbb932f97355..27851fb0e25b 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
>>>>> @@ -1149,7 +1149,7 @@ int amdgpu_driver_open_kms(struct drm_device 
>>>>> *dev, struct drm_file *file_priv)
>>>>>   {
>>>>>       struct amdgpu_device *adev = drm_to_adev(dev);
>>>>>       struct amdgpu_fpriv *fpriv;
>>>>> -    int r, pasid;
>>>>> +    int r;
>>>>>         /* Ensure IB tests are run on ring */
>>>>>       flush_delayed_work(&adev->delayed_init_work);
>>>>> @@ -1172,15 +1172,9 @@ int amdgpu_driver_open_kms(struct 
>>>>> drm_device *dev, struct drm_file *file_priv)
>>>>>           goto out_suspend;
>>>>>       }
>>>>>   -    pasid = amdgpu_pasid_alloc(16);
>>>>> -    if (pasid < 0) {
>>>>> -        dev_warn(adev->dev, "No more PASIDs available!");
>>>>> -        pasid = 0;
>>>>> -    }
>>>>> -
>>>>> -    r = amdgpu_vm_init(adev, &fpriv->vm, pasid);
>>>>> +    r = amdgpu_vm_init(adev, &fpriv->vm);
>>>>>       if (r)
>>>>> -        goto error_pasid;
>>>>> +        goto free_fpriv;
>>>>>         fpriv->prt_va = amdgpu_vm_bo_add(adev, &fpriv->vm, NULL);
>>>>>       if (!fpriv->prt_va) {
>>>>> @@ -1208,10 +1202,7 @@ int amdgpu_driver_open_kms(struct 
>>>>> drm_device *dev, struct drm_file *file_priv)
>>>>>   error_vm:
>>>>>       amdgpu_vm_fini(adev, &fpriv->vm);
>>>>>   -error_pasid:
>>>>> -    if (pasid)
>>>>> -        amdgpu_pasid_free(pasid);
>>>>> -
>>>>> +free_fpriv:
>>>>>       kfree(fpriv);
>>>>>     out_suspend:
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>> index 63975bda8e76..562c2c48a3a3 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>> @@ -87,6 +87,69 @@ struct amdgpu_prt_cb {
>>>>>       struct dma_fence_cb cb;
>>>>>   };
>>>>>   +static int amdgpu_vm_pasid_alloc(struct amdgpu_device *adev,
>>>>> +                 struct amdgpu_vm *vm, unsigned int pasid)
>>>>> +{
>>>>> +    unsigned long flags;
>>>>> +    int r;
>>>>> +
>>>>> +    if (!pasid)
>>>>> +        return 0;
>>>>> +
>>>>> + 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)
>>>>> +        return r;
>>>>> +
>>>>> +    vm->pasid = pasid;
>>>>> +    return 0;
>>>>> +}
>>>>> +static void amdgpu_vm_pasid_remove_id(struct amdgpu_device *adev,
>>>>> +                      unsigned int pasid)
>>>>> +{
>>>>> +    unsigned long flags;
>>>>> +
>>>>> +    if (!pasid)
>>>>> +        return;
>>>>> +
>>>>> + 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);
>>>>> +
>>>>> +}
>>>>> +
>>>>> +static void amdgpu_vm_pasid_remove(struct amdgpu_device *adev,
>>>>> +                   struct amdgpu_vm *vm)
>>>>> +{
>>>>> +    amdgpu_vm_pasid_remove_id(adev, vm->pasid);
>>>>> +    vm->pasid = 0;
>>>>> +}
>>>>> +
>>>>> +static void amdgpu_vm_pasid_free(struct amdgpu_device *adev,
>>>>> +                 struct amdgpu_vm *vm)
>>>>> +{
>>>>> +    if (!vm->pasid)
>>>>> +        return;
>>>>> +
>>>>> +    amdgpu_pasid_free(vm->pasid);
>>>>> +    amdgpu_vm_pasid_remove(adev, vm);
>>>>> +}
>>>>> +
>>>>> +static struct amdgpu_vm *amdgpu_vm_pasid_find(struct 
>>>>> amdgpu_device *adev,
>>>>> +                          unsigned int pasid)
>>>>> +{
>>>>> +    struct amdgpu_vm *vm;
>>>>> +    unsigned long flags;
>>>>> +
>>>>> + spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
>>>>> +    vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
>>>>> + spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
>>>>> +
>>>>> +    return vm;
>>>>> +}
>>>>> +
>>>>>   /*
>>>>>    * vm eviction_lock can be taken in MMU notifiers. Make sure no 
>>>>> reclaim-FS
>>>>>    * happens while holding this lock anywhere to prevent deadlocks 
>>>>> when
>>>>> @@ -2859,17 +2922,17 @@ long amdgpu_vm_wait_idle(struct amdgpu_vm 
>>>>> *vm, long timeout)
>>>>>    *
>>>>>    * @adev: amdgpu_device pointer
>>>>>    * @vm: requested vm
>>>>> - * @pasid: Process address space identifier
>>>>>    *
>>>>>    * Init @vm fields.
>>>>>    *
>>>>>    * Returns:
>>>>>    * 0 for success, error for failure.
>>>>>    */
>>>>> -int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm 
>>>>> *vm, u32 pasid)
>>>>> +int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>>>>>   {
>>>>>       struct amdgpu_bo *root_bo;
>>>>>       struct amdgpu_bo_vm *root;
>>>>> +    unsigned int pasid;
>>>>>       int r, i;
>>>>>         vm->va = RB_ROOT_CACHED;
>>>>> @@ -2940,19 +3003,15 @@ 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;
>>>>> +    pasid = amdgpu_pasid_alloc(16);
>>>>> +    if (pasid < 0) {
>>>>> +        dev_warn(adev->dev, "No more PASIDs available!");
>>>>> +        pasid = 0;
>>>>>       }
>>>>>   +    if (amdgpu_vm_pasid_alloc(adev, vm, pasid))
>>>>> +        goto error_free_pasid;
>>>>> +
>>>>>       INIT_KFIFO(vm->faults);
>>>>>         return 0;
>>>>> @@ -2960,6 +3019,10 @@ int amdgpu_vm_init(struct amdgpu_device 
>>>>> *adev, struct amdgpu_vm *vm, u32 pasid)
>>>>>   error_unreserve:
>>>>>       amdgpu_bo_unreserve(vm->root.bo);
>>>>>   +error_free_pasid:
>>>>> +    if (pasid)
>>>>> +        amdgpu_pasid_free(pasid);
>>>>> +
>>>>>   error_free_root:
>>>>>       amdgpu_bo_unref(&root->shadow);
>>>>>       amdgpu_bo_unref(&root_bo);
>>>>> @@ -3039,18 +3102,11 @@ 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);
>>>>> +    r = amdgpu_vm_pasid_alloc(adev, vm, pasid);
>>>>> +    if (r ==  -ENOSPC)
>>>>> +        goto unreserve_bo;
>>>>>   -        if (r == -ENOSPC)
>>>>> -            goto unreserve_bo;
>>>>> -        r = 0;
>>>>> -    }
>>>>> +    r = 0;
>>>>>         /* Check if PD needs to be reinitialized and do it before
>>>>>        * changing any other state, in case it fails.
>>>>> @@ -3088,19 +3144,7 @@ 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);
>>>>> -
>>>>> -        /* Free the original amdgpu allocated pasid
>>>>> -         * Will be replaced with kfd allocated pasid
>>>>> -         */
>>>>> -        amdgpu_pasid_free(vm->pasid);
>>>>> -        vm->pasid = 0;
>>>>> -    }
>>>>> +    amdgpu_vm_pasid_free(adev, vm);
>>>>>         /* Free the shadow bo for compute VM */
>>>>> amdgpu_bo_unref(&to_amdgpu_bo_vm(vm->root.bo)->shadow);
>>>>> @@ -3111,13 +3155,8 @@ int amdgpu_vm_make_compute(struct 
>>>>> amdgpu_device *adev, struct amdgpu_vm *vm,
>>>>>       goto unreserve_bo;
>>>>>     free_idr:
>>>>> -    if (pasid) {
>>>>> -        unsigned long flags;
>>>>> +    amdgpu_vm_pasid_remove_id(adev, pasid);
>>>>>   - 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 +3172,7 @@ 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);
>>>>>       vm->is_compute_context = false;
>>>>>   }
>>>>>   @@ -3164,15 +3196,7 @@ 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);
>>>>>       dma_fence_wait(vm->last_unlocked, false);
>>>>>       dma_fence_put(vm->last_unlocked);
>>>>>   @@ -3334,16 +3358,10 @@ int amdgpu_vm_ioctl(struct drm_device 
>>>>> *dev, void *data, struct drm_file *filp)
>>>>>   void amdgpu_vm_get_task_info(struct amdgpu_device *adev, u32 pasid,
>>>>>                struct amdgpu_task_info *task_info)
>>>>>   {
>>>>> -    struct amdgpu_vm *vm;
>>>>> -    unsigned long flags;
>>>>> +    struct amdgpu_vm *vm = amdgpu_vm_pasid_find(adev, pasid);
>>>>>   - spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
>>>>> -
>>>>> -    vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
>>>>>       if (vm)
>>>>>           *task_info = vm->task_info;
>>>>> -
>>>>> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
>>>>>   }
>>>>>     /**
>>>>> @@ -3380,24 +3398,16 @@ bool amdgpu_vm_handle_fault(struct 
>>>>> amdgpu_device *adev, u32 pasid,
>>>>>   {
>>>>>       bool is_compute_context = false;
>>>>>       struct amdgpu_bo *root;
>>>>> -    unsigned long irqflags;
>>>>>       uint64_t value, flags;
>>>>>       struct amdgpu_vm *vm;
>>>>>       int r;
>>>>>   - spin_lock_irqsave(&adev->vm_manager.pasid_lock, irqflags);
>>>>> -    vm = idr_find(&adev->vm_manager.pasid_idr, 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);
>>>>> -
>>>>> -    if (!root)
>>>>> +    vm = amdgpu_vm_pasid_find(adev, pasid);
>>>>> +    if (!vm)
>>>>>           return false;
>>>>>   +    root = amdgpu_bo_ref(vm->root.bo);
>>>>> +        is_compute_context = vm->is_compute_context;
>>>>>       addr /= AMDGPU_GPU_PAGE_SIZE;
>>>>>         if (is_compute_context &&
>>>>> @@ -3411,12 +3421,8 @@ 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);
>>>>> -    if (vm && vm->root.bo != root)
>>>>> -        vm = NULL;
>>>>> - spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, irqflags);
>>>>> -    if (!vm)
>>>>> +    vm = amdgpu_vm_pasid_find(adev, pasid);
>>>>> +    if (!vm || (vm && vm->root.bo != root))
>>>>>           goto error_unlock;
>>>>>         flags = AMDGPU_PTE_VALID | AMDGPU_PTE_SNOOPED |
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h 
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>> index ddb85a85cbba..ee994e21dffa 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>> @@ -376,7 +376,7 @@ void amdgpu_vm_manager_init(struct 
>>>>> amdgpu_device *adev);
>>>>>   void amdgpu_vm_manager_fini(struct amdgpu_device *adev);
>>>>>     long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout);
>>>>> -int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm 
>>>>> *vm, u32 pasid);
>>>>> +int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm 
>>>>> *vm);
>>>>>   int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct 
>>>>> amdgpu_vm *vm, u32 pasid);
>>>>>   void amdgpu_vm_release_compute(struct amdgpu_device *adev, 
>>>>> struct amdgpu_vm *vm);
>>>>>   void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm 
>>>>> *vm);
>>>
>
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