[PATCH 1/2] drm/amdgpu: Moved fault hash table to amdgpu vm

Kuehling, Felix Felix.Kuehling at amd.com
Thu Sep 13 04:45:51 UTC 2018


I think I'm missing something. I thought the whole discussion we were having about tracking current and future locations of page tables was about swapping out page tables that are managed by HMM. We currently do swap out page tables that don't have fence on them and that are not managed by HMM. And pipelining that is not a problem today.

You're raising some potential problems that I think must be about swapping out page tables that don't have fences on them (otherwise they wouldn't be evicted) and that are managed by HMM. If there is no fence on the page table, no engine that can't handle page faults can depend on the page tables. So we can discard the contents and set the parent page directory entry to invalid. Setting the parent PDE needs to be synchronous so that the GPU doesn't try to access a page table that is no longer there. No pipelining, no problem.

Then you came back with an argument "what about engines that don't support page faults". Those engines can't use memory mapped by HMM anyway. And they can't be evicted while they have a fence on them that indicates active usage by such an engine.

You seem to see some problems that require not pipelining page table evictions. I still don't understand what the problem is. I think we should have a phone call to sort this out.

A few more comments inline, but I think we're misunderstanding each other ...

>>>>> 5. The new system memory location of the page table is noted in its BO.
>>>> You mean in the parent page table? You can just invalidate the entry in
>>>> the parent page table and let it fault.
>>> I'm repeating myself, but exactly that is what won't work.
>>>
>>> See we still have engines which can't handle page faults which uses
>>> the same VM at the same time. This means that we can't just fault in
>>> page tables.
>> And I don't understand why that is a problem. Those clients rely on
>> fences to keep their BOs resident, including the page tables. Are you
>> planning to change that?
> 
> No, but how do you want to swap out page tables when there is a fence added?

I don't. That's my point. If the page table has fences on it, it can't be swapped out. So there is no problem.

> 
> Or do you want to stop adding fences to page tables for engines with
> recoverable faults?

Yes, that was my assumption, coming from a KFD perspective where with HMM we want to get away from our eviction fences that enforce BO residency, including page tables. Right now signaling an eviction fence means stopping user mode queues. We want to stop doing that.

If page tables get evicted, that's fine as long as those virtual addresses aren't accessed. Once an access happens, the page table needs to be restored or recreated. Once that's done, the retrying hardware block will get a successful translation and continue executing.

> 
> I think that is completely unrealistic considering the performance
> penalty of faults.

I agree that evicting a page table that's in active use is bad. For amdgpu_cs you can prevent that with a fence, no problem.

But a fence is not a good way to prevent that for KFD, because it forces us to keep using our eviction fence and preempting user mode queues on evictions. You see, the eviction fence does not prevent the page table from being evicted, but it forces us to preempt all our queues when an eviction happens. That is a worse performance penalty than dealing with a page fault because the page fault is much more selective. A page fault can interrupt a compute shader at wave granularity. An preemption interrupts compute shaders with process granularity and at much longer time scales.

For KFD I would try to find a better way to avoid evictions of page tables, maybe by bumping them up in the LRU at appropriate times. But even without any such improvements, page faults are still better for KFD than the current eviction-fence-based approach.

Regards,
  Felix

> 
> At least for currently available hardware we should limit page faults to
> be used in as few cases as possible, e.g. SVM and userptr.
> 
> Regards,
> Christian.
________________________________________
From: Koenig, Christian
Sent: Wednesday, September 12, 2018 11:59 AM
To: Kuehling, Felix; Zeng, Oak; Oak Zeng; amd-gfx at lists.freedesktop.org; Yang, Philip
Subject: Re: [PATCH 1/2] drm/amdgpu: Moved fault hash table to amdgpu vm

Am 12.09.2018 um 17:29 schrieb Felix Kuehling:
> On 2018-09-12 02:56 AM, Christian König wrote:
>> Am 12.09.2018 um 00:00 schrieb Felix Kuehling:
>>> On 2018-09-11 03:19 AM, Christian König wrote:
>>>> Hi Felix,
>>>>
>>>> let me try to explain the problem on an example:
>>>>
>>>> 1. We have a running job which needs recoverable page faults for
>>>> accessing the process address space.
>>>> 2. We run into memory pressure on VRAM and start to evict things.
>>>> 3. A page tables of the running job is picked up for eviction.
>>>> 4. We schedule a copy command to move the content of the page table to
>>>> system memory.
>>> I think we should change this. If you evict a page table, you don't need
>>> to preserve its contents. You should be able to restore the page table
>>> contents from scratch when you handle the page fault that restores it.
>> Yeah, already implemented. You actually don't need the page fault for
>> that.
>>
>>>> 5. The new system memory location of the page table is noted in its BO.
>>> You mean in the parent page table? You can just invalidate the entry in
>>> the parent page table and let it fault.
>> I'm repeating myself, but exactly that is what won't work.
>>
>> See we still have engines which can't handle page faults which uses
>> the same VM at the same time. This means that we can't just fault in
>> page tables.
> And I don't understand why that is a problem. Those clients rely on
> fences to keep their BOs resident, including the page tables. Are you
> planning to change that?

No, but how do you want to swap out page tables when there is a fence added?

Or do you want to stop adding fences to page tables for engines with
recoverable faults?

I think that is completely unrealistic considering the performance
penalty of faults.

At least for currently available hardware we should limit page faults to
be used in as few cases as possible, e.g. SVM and userptr.

Regards,
Christian.

>
> Regards,
>    Felix
>
>> What we could do is to separate the address space into a low and a
>> high range where we have different handling for both.
>>
>> I've already prototyped this and prepared mostly everything necessary
>> for that, but that is still not 100% completed.
>>
>> Regards,
>> Christian.
>>
>>>> 6. We get a fault from the job and swap in the page from the process
>>>> address space.
>>> No. Then you need to keep updating page tables that are swapped out.
>>> Instead just discard them and rebuild on fault.
>>>
>>>> 7. Now we need to enter the new page address into the page table ->
>>>> *BAM*
>>>>
>>>> The problem is now that we don't know the address of the page table
>>>> because the current location was replaced with the future location in
>>>> step #5.
>>> You solve that problem by discarding page tables that are swapped out.
>>> Then there is no future location.
>>>
>>>> We could now argue that we could update the page tables on the fly for
>>>> the evicted page and never wait for the current job to finish, but
>>>> this won't work because not all engines can handle that.
>>> Engines that can't handle page faults will depend on fences to keep
>>> their page tables resident, like we do today. So they won't have this
>>> problem.
>>>
>>> Regards,
>>>     Felix
>>>
>>>> I will circumvent this problem for now by blocking the eviction before
>>>> step #5. The issue with that is that this pipelining is responsible
>>>> for nearly 20% of the fps in some testcases.
>>>>
>>>> I hope that it won't be that bad when I limit disabling the pipelining
>>>> to only page tables, but it is certainly possible that we will get
>>>> pushback on this.
>>>>
>>>> If that happens we probably need to add some flags to limit this
>>>> workaround even more to only the root PD and all the PDs/PTs which are
>>>> involved in recoverable faults.
>>>>
>>>> Regards,
>>>> Christian.
>>>>
>>>> Am 10.09.2018 um 21:10 schrieb Felix Kuehling:
>>>>> I'm not sure why you need to distinguish current and future state when
>>>>> dealing with page faults. When you get a page fault, you know that the
>>>>> GPU is trying to access memory right now, in the present. So you're
>>>>> always working with the current state. When the CPU page table
>>>>> changes,
>>>>> you get an MMU notifier that allows you to invalidate the
>>>>> corresponding
>>>>> GPU PTEs. If you have a valid GPU PTE, it always represents the
>>>>> current
>>>>> states and is in sync with the CPU page table. If the GPU page
>>>>> table is
>>>>> ever outdated, it should have an invalid entry in that place.
>>>>>
>>>>> If SDMA is used to update the GPU PTEs, there is a delay. The MMU
>>>>> notifier is synchronous, so it shouldn't be a problem. You just
>>>>> wait for
>>>>> the SDMA job to complete before returning. When updating PTEs with new
>>>>> valid addresses, it's asynchronous. But the GPU will continue retrying
>>>>> on the invalid entry until SDMA finishes. So it's also implicitly
>>>>> synchronized on the GPU side.
>>>>>
>>>>> Regards,
>>>>>      Felix
>>>>>
>>>>>
>>>>> On 2018-09-10 05:42 AM, Christian König wrote:
>>>>>> Hi Felix & Oak,
>>>>>>
>>>>>> over the weekend I had the idea that we could just use the shadow BOs
>>>>>> to have the current state in a page fault. They are GTT BOs and CPU
>>>>>> accessible anyway.
>>>>>>
>>>>>> Regards,
>>>>>> Christian.
>>>>>>
>>>>>> Am 08.09.2018 um 09:34 schrieb Christian König:
>>>>>>> Hi Felix,
>>>>>>>
>>>>>>>> But why do you want to update page tables when there is no more
>>>>>>>> user
>>>>>>>> mode context that cares about them? Is this just to allow pending
>>>>>>>> work
>>>>>>>> to complete after the user mode context is gone? To prevent hangs?
>>>>>>> The problem I'm see is that we still don't have a reliable way of
>>>>>>> killing a command submission while making sure that no more
>>>>>>> faults of
>>>>>>> it are in the flight.
>>>>>>>
>>>>>>> E.g. the HWS has a function to kill a running job on the hardware,
>>>>>>> but that only works for compute and there is no way of telling when
>>>>>>> that operation has finished.
>>>>>>>
>>>>>>> But Oak has already convinced me that we should probably work on
>>>>>>> that
>>>>>>> instead of trying to keep the VM alive as long as possible.
>>>>>>>
>>>>>>> Regards,
>>>>>>> Christian.
>>>>>>>
>>>>>>> Am 08.09.2018 um 02:27 schrieb Felix Kuehling:
>>>>>>>> Hi Christian,
>>>>>>>>
>>>>>>>> I'm not sure I get your point here.
>>>>>>>>
>>>>>>>> As I understand it, the amdgpu_vm structure represents the user
>>>>>>>> mode VM
>>>>>>>> context. It has the pointers to the root page directory and the
>>>>>>>> rest of
>>>>>>>> the page table hierarchy. If there is no amdgpu_vm, there is no
>>>>>>>> user
>>>>>>>> mode context that cares about the page tables.
>>>>>>>>
>>>>>>>> If we leave the page table pointers in the amdgpu_vm, then handling
>>>>>>>> faults after the VM is destroyed is pointless. We can't find the
>>>>>>>> page
>>>>>>>> tables and we can't update them, so there is nothing we can do in
>>>>>>>> response to VM faults.
>>>>>>>>
>>>>>>>> So I'm guessing that you want to move the page table pointers
>>>>>>>> into a
>>>>>>>> different structure that exists half-independently of the VM. It
>>>>>>>> would
>>>>>>>> be created when the VM is created (that's where we currently
>>>>>>>> allocate
>>>>>>>> the PASID) but can be destroyed slightly later.
>>>>>>>>
>>>>>>>> But why do you want to update page tables when there is no more
>>>>>>>> user
>>>>>>>> mode context that cares about them? Is this just to allow pending
>>>>>>>> work
>>>>>>>> to complete after the user mode context is gone? To prevent hangs?
>>>>>>>>
>>>>>>>> Regards,
>>>>>>>>       Felix
>>>>>>>>
>>>>>>>> On 2018-09-10 07:20 AM, Christian König wrote:
>>>>>>>>>> Am I right that the handling of page fault need a valid VM?
>>>>>>>>> No, exactly that view is incorrect.
>>>>>>>>>
>>>>>>>>> The VM is meant to be a memory management structure of page
>>>>>>>>> tables and
>>>>>>>>> is completely pointless fault processing because it represent the
>>>>>>>>> future state of the page tables and not the current one.
>>>>>>>>>
>>>>>>>>> What we need for fault processing is a new structure build around
>>>>>>>>> PASIDs which is feed by the with addresses when page tables are
>>>>>>>>> moved
>>>>>>>>> around.
>>>>>>>>>
>>>>>>>>> Alternatively I hope that we can use the SDMA to walk the page
>>>>>>>>> tables
>>>>>>>>> and update the required entries by just using the address.
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> Christian.
>>>>>>>>>
>>>>>>>>> Am 07.09.2018 um 16:55 schrieb Zeng, Oak:
>>>>>>>>>> Hi Christian,
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> What is the value of delay the destroy of hash to after vm is
>>>>>>>>>> destroyed? Since vm is destroyed, you basically don’t have enough
>>>>>>>>>> information to paging in the correct page to gpuvm. Am I right
>>>>>>>>>> that
>>>>>>>>>> the handling of page fault need a valid VM? For example, you
>>>>>>>>>> need the
>>>>>>>>>> VM to get the corresponding physical address of the faulty page.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> After vm is destroyed, the retry interrupt can be directly
>>>>>>>>>> discard as
>>>>>>>>>> you can’t find vm through pasid. You can think this is also one
>>>>>>>>>> kind
>>>>>>>>>> of prescreen.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> So I am stand for the point that, there is no need to delay the
>>>>>>>>>> destroy of hash to after vm is destroyed. Prescreening hash
>>>>>>>>>> can be
>>>>>>>>>> destroyed at the time of vm_fini.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>>
>>>>>>>>>> Oak
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> *From:*Christian König <ckoenig.leichtzumerken at gmail.com>
>>>>>>>>>> *Sent:* Friday, September 07, 2018 4:39 AM
>>>>>>>>>> *To:* Zeng, Oak <Oak.Zeng at amd.com>; Oak Zeng
>>>>>>>>>> <zengshanjun at gmail.com>;
>>>>>>>>>> amd-gfx at lists.freedesktop.org
>>>>>>>>>> *Cc:* Zeng, Oak <Oak.Zeng at amd.com>
>>>>>>>>>> *Subject:* Re: [PATCH 1/2] drm/amdgpu: Moved fault hash table to
>>>>>>>>>> amdgpu vm
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Hi Oak,
>>>>>>>>>>
>>>>>>>>>> yeah, but this is still a NAK. Making the hash per PASID was
>>>>>>>>>> not a
>>>>>>>>>> suggestion but rather a must have.
>>>>>>>>>>
>>>>>>>>>> The VM structures must be destroyed while the processing is still
>>>>>>>>>> ongoing, or otherwise we would not have a clean OOM handling.
>>>>>>>>>>
>>>>>>>>>> The IDR for PASID lockup can be put into amdgpu_ids.c, you can
>>>>>>>>>> just
>>>>>>>>>> replace the IDA already used there with an IDR.
>>>>>>>>>>
>>>>>>>>>> Since the PASID is already freed up delayed we should have the
>>>>>>>>>> grace
>>>>>>>>>> period for interrupt processing included. If that still isn't
>>>>>>>>>> sufficient we can still add some delayed work for this.
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>> Christian.
>>>>>>>>>>
>>>>>>>>>> Am 07.09.2018 um 06:16 schrieb ozeng:
>>>>>>>>>>
>>>>>>>>>>         Hi Christian,
>>>>>>>>>>
>>>>>>>>>>         In this implementation, fault hash is made per vm, not per
>>>>>>>>>> pasid
>>>>>>>>>>         as suggested, based on below considerations:
>>>>>>>>>>
>>>>>>>>>>           * Delay the destroy of hash introduces more effort like
>>>>>>>>>> how to
>>>>>>>>>>             set the proper grace period after which no retry
>>>>>>>>>> interrupt
>>>>>>>>>>             will be generated. We want to avoid those complication
>>>>>>>>>> if we
>>>>>>>>>>             can.
>>>>>>>>>>           * The  problem of the per vm implementation is that it
>>>>>>>>>> is hard
>>>>>>>>>>             to delay the destroy of fault hash, because when vm is
>>>>>>>>>>             destroyed, prescreen function won't be able to
>>>>>>>>>> retrieve the
>>>>>>>>>>             fault hash. But in this case, the prescreen
>>>>>>>>>> function can
>>>>>>>>>>             either let the interrupt go through (to gmc) or ignore
>>>>>>>>>> it.
>>>>>>>>>>             From this perspective, it is not very necessary to
>>>>>>>>>> delay the
>>>>>>>>>>             destroy of hash table.
>>>>>>>>>>           * On the other hand, since ASICs after vega10 have the
>>>>>>>>>> HW CAM
>>>>>>>>>>             feature. So the SW IV prescreen is only useful for
>>>>>>>>>> vega10.
>>>>>>>>>>             For all the HW implemented CAM, we can consider the
>>>>>>>>>> delayed
>>>>>>>>>>             CAM acknowledgment.
>>>>>>>>>>           * Making it per pasid need to introduce another idr to
>>>>>>>>>>             correlate pasid and hash table - where to put the idr?
>>>>>>>>>> You
>>>>>>>>>>             will have to make it a global variable which is not
>>>>>>>>>> very
>>>>>>>>>>             desirable.
>>>>>>>>>>
>>>>>>>>>>         The main purpose of this patch is to solve the
>>>>>>>>>> inter-process
>>>>>>>>>> lock
>>>>>>>>>>         issue (when hash table is full), while still keep codes
>>>>>>>>>> simple.
>>>>>>>>>>
>>>>>>>>>>         Also with this patch, the faults kfifo is not necessary
>>>>>>>>>> any
>>>>>>>>>> more.
>>>>>>>>>>         See patch 2.
>>>>>>>>>>
>>>>>>>>>>         Regards,
>>>>>>>>>>
>>>>>>>>>>         Oak
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>         On 09/06/2018 11:28 PM, Oak Zeng wrote:
>>>>>>>>>>
>>>>>>>>>>             In stead of share one fault hash table per device,
>>>>>>>>>> make it
>>>>>>>>>>
>>>>>>>>>>             per vm. This can avoid inter-process lock issue when
>>>>>>>>>> fault
>>>>>>>>>>
>>>>>>>>>>             hash table is full.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             Change-Id: I5d1281b7c41eddc8e26113e010516557588d3708
>>>>>>>>>>
>>>>>>>>>>             Signed-off-by: Oak Zeng <Oak.Zeng at amd.com>
>>>>>>>>>> <mailto:Oak.Zeng at amd.com>
>>>>>>>>>>
>>>>>>>>>>             Suggested-by: Christian Konig
>>>>>>>>>> <Christian.Koenig at amd.com>
>>>>>>>>>> <mailto:Christian.Koenig at amd.com>
>>>>>>>>>>
>>>>>>>>>>             Suggested-by: Felix Kuehling <Felix.Kuehling at amd.com>
>>>>>>>>>> <mailto:Felix.Kuehling at amd.com>
>>>>>>>>>>
>>>>>>>>>>             ---
>>>>>>>>>>
>>>>>>>>>>              drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c |  75
>>>>>>>>>> ------------------------
>>>>>>>>>>
>>>>>>>>>>              drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h |  10 ----
>>>>>>>>>>
>>>>>>>>>>              drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 102
>>>>>>>>>> ++++++++++++++++++++++++++++++++-
>>>>>>>>>>
>>>>>>>>>>              drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h |  12 ++++
>>>>>>>>>>
>>>>>>>>>>              drivers/gpu/drm/amd/amdgpu/vega10_ih.c |  38
>>>>>>>>>> +++++-------
>>>>>>>>>>
>>>>>>>>>>              5 files changed, 127 insertions(+), 110 deletions(-)
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
>>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
>>>>>>>>>>
>>>>>>>>>>             index 06373d4..4ed8621 100644
>>>>>>>>>>
>>>>>>>>>>             --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
>>>>>>>>>>
>>>>>>>>>>             +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
>>>>>>>>>>
>>>>>>>>>>             @@ -197,78 +197,3 @@ int amdgpu_ih_process(struct
>>>>>>>>>> amdgpu_device *adev)
>>>>>>>>>>
>>>>>>>>>>                return IRQ_HANDLED;
>>>>>>>>>>
>>>>>>>>>>              }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             -/**
>>>>>>>>>>
>>>>>>>>>>             - * amdgpu_ih_add_fault - Add a page fault record
>>>>>>>>>>
>>>>>>>>>>             - *
>>>>>>>>>>
>>>>>>>>>>             - * @adev: amdgpu device pointer
>>>>>>>>>>
>>>>>>>>>>             - * @key: 64-bit encoding of PASID and address
>>>>>>>>>>
>>>>>>>>>>             - *
>>>>>>>>>>
>>>>>>>>>>             - * This should be called when a retry page fault
>>>>>>>>>> interrupt is
>>>>>>>>>>
>>>>>>>>>>             - * received. If this is a new page fault, it will be
>>>>>>>>>> added to a hash
>>>>>>>>>>
>>>>>>>>>>             - * table. The return value indicates whether this
>>>>>>>>>> is a
>>>>>>>>>> new fault, or
>>>>>>>>>>
>>>>>>>>>>             - * a fault that was already known and is already
>>>>>>>>>> being
>>>>>>>>>> handled.
>>>>>>>>>>
>>>>>>>>>>             - *
>>>>>>>>>>
>>>>>>>>>>             - * If there are too many pending page faults, this
>>>>>>>>>> will
>>>>>>>>>> fail. Retry
>>>>>>>>>>
>>>>>>>>>>             - * interrupts should be ignored in this case until
>>>>>>>>>> there
>>>>>>>>>> is enough
>>>>>>>>>>
>>>>>>>>>>             - * free space.
>>>>>>>>>>
>>>>>>>>>>             - *
>>>>>>>>>>
>>>>>>>>>>             - * Returns 0 if the fault was added, 1 if the
>>>>>>>>>> fault was
>>>>>>>>>> already known,
>>>>>>>>>>
>>>>>>>>>>             - * -ENOSPC if there are too many pending faults.
>>>>>>>>>>
>>>>>>>>>>             - */
>>>>>>>>>>
>>>>>>>>>>             -int amdgpu_ih_add_fault(struct amdgpu_device
>>>>>>>>>> *adev, u64
>>>>>>>>>> key)
>>>>>>>>>>
>>>>>>>>>>             -{
>>>>>>>>>>
>>>>>>>>>>             -  unsigned long flags;
>>>>>>>>>>
>>>>>>>>>>             -  int r = -ENOSPC;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  if (WARN_ON_ONCE(!adev->irq.ih.faults))
>>>>>>>>>>
>>>>>>>>>>             -          /* Should be allocated in
>>>>>>>>>> <IP>_ih_sw_init on
>>>>>>>>>> GPUs that
>>>>>>>>>>
>>>>>>>>>>             -           * support retry faults and require retry
>>>>>>>>>> filtering.
>>>>>>>>>>
>>>>>>>>>>             -           */
>>>>>>>>>>
>>>>>>>>>>             -          return r;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             - spin_lock_irqsave(&adev->irq.ih.faults->lock,
>>>>>>>>>> flags);
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  /* Only let the hash table fill up to 50% for best
>>>>>>>>>> performance */
>>>>>>>>>>
>>>>>>>>>>             -  if (adev->irq.ih.faults->count >= (1 <<
>>>>>>>>>> (AMDGPU_PAGEFAULT_HASH_BITS-1)))
>>>>>>>>>>
>>>>>>>>>>             -          goto unlock_out;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  r = chash_table_copy_in(&adev->irq.ih.faults->hash,
>>>>>>>>>> key, NULL);
>>>>>>>>>>
>>>>>>>>>>             -  if (!r)
>>>>>>>>>>
>>>>>>>>>>             -          adev->irq.ih.faults->count++;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  /* chash_table_copy_in should never fail unless
>>>>>>>>>> we're
>>>>>>>>>> losing count */
>>>>>>>>>>
>>>>>>>>>>             -  WARN_ON_ONCE(r < 0);
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -unlock_out:
>>>>>>>>>>
>>>>>>>>>>             - spin_unlock_irqrestore(&adev->irq.ih.faults->lock,
>>>>>>>>>> flags);
>>>>>>>>>>
>>>>>>>>>>             -  return r;
>>>>>>>>>>
>>>>>>>>>>             -}
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -/**
>>>>>>>>>>
>>>>>>>>>>             - * amdgpu_ih_clear_fault - Remove a page fault record
>>>>>>>>>>
>>>>>>>>>>             - *
>>>>>>>>>>
>>>>>>>>>>             - * @adev: amdgpu device pointer
>>>>>>>>>>
>>>>>>>>>>             - * @key: 64-bit encoding of PASID and address
>>>>>>>>>>
>>>>>>>>>>             - *
>>>>>>>>>>
>>>>>>>>>>             - * This should be called when a page fault has been
>>>>>>>>>> handled. Any
>>>>>>>>>>
>>>>>>>>>>             - * future interrupt with this key will be
>>>>>>>>>> processed as a
>>>>>>>>>> new
>>>>>>>>>>
>>>>>>>>>>             - * page fault.
>>>>>>>>>>
>>>>>>>>>>             - */
>>>>>>>>>>
>>>>>>>>>>             -void amdgpu_ih_clear_fault(struct amdgpu_device
>>>>>>>>>> *adev,
>>>>>>>>>> u64 key)
>>>>>>>>>>
>>>>>>>>>>             -{
>>>>>>>>>>
>>>>>>>>>>             -  unsigned long flags;
>>>>>>>>>>
>>>>>>>>>>             -  int r;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  if (!adev->irq.ih.faults)
>>>>>>>>>>
>>>>>>>>>>             -          return;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             - spin_lock_irqsave(&adev->irq.ih.faults->lock,
>>>>>>>>>> flags);
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  r = chash_table_remove(&adev->irq.ih.faults->hash,
>>>>>>>>>> key, NULL);
>>>>>>>>>>
>>>>>>>>>>             -  if (!WARN_ON_ONCE(r < 0)) {
>>>>>>>>>>
>>>>>>>>>>             -          adev->irq.ih.faults->count--;
>>>>>>>>>>
>>>>>>>>>>             - WARN_ON_ONCE(adev->irq.ih.faults->count < 0);
>>>>>>>>>>
>>>>>>>>>>             -  }
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             - spin_unlock_irqrestore(&adev->irq.ih.faults->lock,
>>>>>>>>>> flags);
>>>>>>>>>>
>>>>>>>>>>             -}
>>>>>>>>>>
>>>>>>>>>>             diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
>>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
>>>>>>>>>>
>>>>>>>>>>             index a23e1c0..f411ffb 100644
>>>>>>>>>>
>>>>>>>>>>             --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
>>>>>>>>>>
>>>>>>>>>>             +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.h
>>>>>>>>>>
>>>>>>>>>>             @@ -32,13 +32,6 @@ struct amdgpu_device;
>>>>>>>>>>
>>>>>>>>>>              #define AMDGPU_IH_CLIENTID_LEGACY 0
>>>>>>>>>>
>>>>>>>>>>              #define AMDGPU_IH_CLIENTID_MAX SOC15_IH_CLIENTID_MAX
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             -#define AMDGPU_PAGEFAULT_HASH_BITS 8
>>>>>>>>>>
>>>>>>>>>>             -struct amdgpu_retryfault_hashtable {
>>>>>>>>>>
>>>>>>>>>>             -  DECLARE_CHASH_TABLE(hash,
>>>>>>>>>> AMDGPU_PAGEFAULT_HASH_BITS,
>>>>>>>>>> 8, 0);
>>>>>>>>>>
>>>>>>>>>>             -  spinlock_t     lock;
>>>>>>>>>>
>>>>>>>>>>             -  int            count;
>>>>>>>>>>
>>>>>>>>>>             -};
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>              /*
>>>>>>>>>>
>>>>>>>>>>               * R6xx+ IH ring
>>>>>>>>>>
>>>>>>>>>>               */
>>>>>>>>>>
>>>>>>>>>>             @@ -57,7 +50,6 @@ struct amdgpu_ih_ring {
>>>>>>>>>>
>>>>>>>>>>                bool                   use_doorbell;
>>>>>>>>>>
>>>>>>>>>>                bool                   use_bus_addr;
>>>>>>>>>>
>>>>>>>>>>                dma_addr_t             rb_dma_addr; /* only used
>>>>>>>>>> when
>>>>>>>>>> use_bus_addr = true */
>>>>>>>>>>
>>>>>>>>>>             -  struct amdgpu_retryfault_hashtable *faults;
>>>>>>>>>>
>>>>>>>>>>              };
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>              #define AMDGPU_IH_SRC_DATA_MAX_SIZE_DW 4
>>>>>>>>>>
>>>>>>>>>>             @@ -95,7 +87,5 @@ int amdgpu_ih_ring_init(struct
>>>>>>>>>> amdgpu_device *adev, unsigned ring_size,
>>>>>>>>>>
>>>>>>>>>>                                bool use_bus_addr);
>>>>>>>>>>
>>>>>>>>>>              void amdgpu_ih_ring_fini(struct amdgpu_device *adev);
>>>>>>>>>>
>>>>>>>>>>              int amdgpu_ih_process(struct amdgpu_device *adev);
>>>>>>>>>>
>>>>>>>>>>             -int amdgpu_ih_add_fault(struct amdgpu_device
>>>>>>>>>> *adev, u64
>>>>>>>>>> key);
>>>>>>>>>>
>>>>>>>>>>             -void amdgpu_ih_clear_fault(struct amdgpu_device
>>>>>>>>>> *adev,
>>>>>>>>>> u64 key);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>              #endif
>>>>>>>>>>
>>>>>>>>>>             diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>>>>>>>
>>>>>>>>>>             index 1d7e3c1..8b220e9 100644
>>>>>>>>>>
>>>>>>>>>>             --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>>>>>>>
>>>>>>>>>>             +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>>>>>>>>>
>>>>>>>>>>             @@ -2692,6 +2692,22 @@ void
>>>>>>>>>> amdgpu_vm_adjust_size(struct
>>>>>>>>>> amdgpu_device *adev, uint32_t min_vm_size,
>>>>>>>>>>
>>>>>>>>>>                         adev->vm_manager.fragment_size);
>>>>>>>>>>
>>>>>>>>>>              }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             +static struct amdgpu_retryfault_hashtable
>>>>>>>>>> *init_fault_hash(void)
>>>>>>>>>>
>>>>>>>>>>             +{
>>>>>>>>>>
>>>>>>>>>>             +  struct amdgpu_retryfault_hashtable *fault_hash;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  fault_hash = kmalloc(sizeof(*fault_hash),
>>>>>>>>>> GFP_KERNEL);
>>>>>>>>>>
>>>>>>>>>>             +  if (!fault_hash)
>>>>>>>>>>
>>>>>>>>>>             +          return fault_hash;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  INIT_CHASH_TABLE(fault_hash->hash,
>>>>>>>>>>
>>>>>>>>>>             +                  AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
>>>>>>>>>>
>>>>>>>>>>             +  spin_lock_init(&fault_hash->lock);
>>>>>>>>>>
>>>>>>>>>>             +  fault_hash->count = 0;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  return fault_hash;
>>>>>>>>>>
>>>>>>>>>>             +}
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>              /**
>>>>>>>>>>
>>>>>>>>>>               * amdgpu_vm_init - initialize a vm instance
>>>>>>>>>>
>>>>>>>>>>               *
>>>>>>>>>>
>>>>>>>>>>             @@ -2780,6 +2796,12 @@ int amdgpu_vm_init(struct
>>>>>>>>>> amdgpu_device *adev, struct amdgpu_vm *vm,
>>>>>>>>>>
>>>>>>>>>>                        vm->pasid = pasid;
>>>>>>>>>>
>>>>>>>>>>                }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             +  vm->fault_hash = init_fault_hash();
>>>>>>>>>>
>>>>>>>>>>             +  if (!vm->fault_hash) {
>>>>>>>>>>
>>>>>>>>>>             +          r = -ENOMEM;
>>>>>>>>>>
>>>>>>>>>>             +          goto error_free_root;
>>>>>>>>>>
>>>>>>>>>>             +  }
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>                INIT_KFIFO(vm->faults);
>>>>>>>>>>
>>>>>>>>>>                vm->fault_credit = 16;
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             @@ -2973,7 +2995,7 @@ void amdgpu_vm_fini(struct
>>>>>>>>>> amdgpu_device *adev, struct amdgpu_vm *vm)
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>                /* Clear pending page faults from IH when the VM is
>>>>>>>>>> destroyed */
>>>>>>>>>>
>>>>>>>>>>                while (kfifo_get(&vm->faults, &fault))
>>>>>>>>>>
>>>>>>>>>>             -          amdgpu_ih_clear_fault(adev, fault);
>>>>>>>>>>
>>>>>>>>>>             +          amdgpu_vm_clear_fault(vm->fault_hash,
>>>>>>>>>> fault);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>                if (vm->pasid) {
>>>>>>>>>>
>>>>>>>>>>                        unsigned long flags;
>>>>>>>>>>
>>>>>>>>>>             @@ -2983,6 +3005,9 @@ void amdgpu_vm_fini(struct
>>>>>>>>>> amdgpu_device *adev, struct amdgpu_vm *vm)
>>>>>>>>>>
>>>>>>>>>> spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
>>>>>>>>>>
>>>>>>>>>>                }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             +  kfree(vm->fault_hash);
>>>>>>>>>>
>>>>>>>>>>             +  vm->fault_hash = NULL;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>                drm_sched_entity_destroy(&vm->entity);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>                if (!RB_EMPTY_ROOT(&vm->va.rb_root)) {
>>>>>>>>>>
>>>>>>>>>>             @@ -3183,3 +3208,78 @@ void
>>>>>>>>>> amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
>>>>>>>>>>
>>>>>>>>>>                        }
>>>>>>>>>>
>>>>>>>>>>                }
>>>>>>>>>>
>>>>>>>>>>              }
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +/**
>>>>>>>>>>
>>>>>>>>>>             + * amdgpu_vm_add_fault - Add a page fault record to
>>>>>>>>>> fault hash table
>>>>>>>>>>
>>>>>>>>>>             + *
>>>>>>>>>>
>>>>>>>>>>             + * @fault_hash: fault hash table
>>>>>>>>>>
>>>>>>>>>>             + * @key: 64-bit encoding of PASID and address
>>>>>>>>>>
>>>>>>>>>>             + *
>>>>>>>>>>
>>>>>>>>>>             + * This should be called when a retry page fault
>>>>>>>>>> interrupt is
>>>>>>>>>>
>>>>>>>>>>             + * received. If this is a new page fault, it will be
>>>>>>>>>> added to a hash
>>>>>>>>>>
>>>>>>>>>>             + * table. The return value indicates whether this
>>>>>>>>>> is a
>>>>>>>>>> new fault, or
>>>>>>>>>>
>>>>>>>>>>             + * a fault that was already known and is already
>>>>>>>>>> being
>>>>>>>>>> handled.
>>>>>>>>>>
>>>>>>>>>>             + *
>>>>>>>>>>
>>>>>>>>>>             + * If there are too many pending page faults, this
>>>>>>>>>> will
>>>>>>>>>> fail. Retry
>>>>>>>>>>
>>>>>>>>>>             + * interrupts should be ignored in this case until
>>>>>>>>>> there
>>>>>>>>>> is enough
>>>>>>>>>>
>>>>>>>>>>             + * free space.
>>>>>>>>>>
>>>>>>>>>>             + *
>>>>>>>>>>
>>>>>>>>>>             + * Returns 0 if the fault was added, 1 if the
>>>>>>>>>> fault was
>>>>>>>>>> already known,
>>>>>>>>>>
>>>>>>>>>>             + * -ENOSPC if there are too many pending faults.
>>>>>>>>>>
>>>>>>>>>>             + */
>>>>>>>>>>
>>>>>>>>>>             +int amdgpu_vm_add_fault(struct
>>>>>>>>>> amdgpu_retryfault_hashtable *fault_hash, u64 key)
>>>>>>>>>>
>>>>>>>>>>             +{
>>>>>>>>>>
>>>>>>>>>>             +  unsigned long flags;
>>>>>>>>>>
>>>>>>>>>>             +  int r = -ENOSPC;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  if (WARN_ON_ONCE(!fault_hash))
>>>>>>>>>>
>>>>>>>>>>             +          /* Should be allocated in amdgpu_vm_init
>>>>>>>>>>
>>>>>>>>>>             +           */
>>>>>>>>>>
>>>>>>>>>>             +          return r;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  spin_lock_irqsave(&fault_hash->lock, flags);
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  /* Only let the hash table fill up to 50% for best
>>>>>>>>>> performance */
>>>>>>>>>>
>>>>>>>>>>             +  if (fault_hash->count >= (1 <<
>>>>>>>>>> (AMDGPU_PAGEFAULT_HASH_BITS-1)))
>>>>>>>>>>
>>>>>>>>>>             +          goto unlock_out;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  r = chash_table_copy_in(&fault_hash->hash, key,
>>>>>>>>>> NULL);
>>>>>>>>>>
>>>>>>>>>>             +  if (!r)
>>>>>>>>>>
>>>>>>>>>>             +          fault_hash->count++;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  /* chash_table_copy_in should never fail unless
>>>>>>>>>> we're
>>>>>>>>>> losing count */
>>>>>>>>>>
>>>>>>>>>>             +  WARN_ON_ONCE(r < 0);
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +unlock_out:
>>>>>>>>>>
>>>>>>>>>>             +  spin_unlock_irqrestore(&fault_hash->lock, flags);
>>>>>>>>>>
>>>>>>>>>>             +  return r;
>>>>>>>>>>
>>>>>>>>>>             +}
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +/**
>>>>>>>>>>
>>>>>>>>>>             + * amdgpu_vm_clear_fault - Remove a page fault record
>>>>>>>>>>
>>>>>>>>>>             + *
>>>>>>>>>>
>>>>>>>>>>             + * @fault_hash: fault hash table
>>>>>>>>>>
>>>>>>>>>>             + * @key: 64-bit encoding of PASID and address
>>>>>>>>>>
>>>>>>>>>>             + *
>>>>>>>>>>
>>>>>>>>>>             + * This should be called when a page fault has been
>>>>>>>>>> handled. Any
>>>>>>>>>>
>>>>>>>>>>             + * future interrupt with this key will be
>>>>>>>>>> processed as a
>>>>>>>>>> new
>>>>>>>>>>
>>>>>>>>>>             + * page fault.
>>>>>>>>>>
>>>>>>>>>>             + */
>>>>>>>>>>
>>>>>>>>>>             +void amdgpu_vm_clear_fault(struct
>>>>>>>>>> amdgpu_retryfault_hashtable *fault_hash, u64 key)
>>>>>>>>>>
>>>>>>>>>>             +{
>>>>>>>>>>
>>>>>>>>>>             +  unsigned long flags;
>>>>>>>>>>
>>>>>>>>>>             +  int r;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  if (!fault_hash)
>>>>>>>>>>
>>>>>>>>>>             +          return;
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  spin_lock_irqsave(&fault_hash->lock, flags);
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  r = chash_table_remove(&fault_hash->hash, key,
>>>>>>>>>> NULL);
>>>>>>>>>>
>>>>>>>>>>             +  if (!WARN_ON_ONCE(r < 0)) {
>>>>>>>>>>
>>>>>>>>>>             +          fault_hash->count--;
>>>>>>>>>>
>>>>>>>>>>             +          WARN_ON_ONCE(fault_hash->count < 0);
>>>>>>>>>>
>>>>>>>>>>             +  }
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +  spin_unlock_irqrestore(&fault_hash->lock, flags);
>>>>>>>>>>
>>>>>>>>>>             +}
>>>>>>>>>>
>>>>>>>>>>             diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>>>>>>>
>>>>>>>>>>             index e275ee7..6eb1da1 100644
>>>>>>>>>>
>>>>>>>>>>             --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>>>>>>>
>>>>>>>>>>             +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>>>>>>>>>>
>>>>>>>>>>             @@ -178,6 +178,13 @@ struct amdgpu_task_info {
>>>>>>>>>>
>>>>>>>>>>                pid_t   tgid;
>>>>>>>>>>
>>>>>>>>>>              };
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             +#define AMDGPU_PAGEFAULT_HASH_BITS 8
>>>>>>>>>>
>>>>>>>>>>             +struct amdgpu_retryfault_hashtable {
>>>>>>>>>>
>>>>>>>>>>             +  DECLARE_CHASH_TABLE(hash,
>>>>>>>>>> AMDGPU_PAGEFAULT_HASH_BITS,
>>>>>>>>>> 8, 0);
>>>>>>>>>>
>>>>>>>>>>             +  spinlock_t     lock;
>>>>>>>>>>
>>>>>>>>>>             +  int            count;
>>>>>>>>>>
>>>>>>>>>>             +};
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>              struct amdgpu_vm {
>>>>>>>>>>
>>>>>>>>>>                /* tree of virtual addresses mapped */
>>>>>>>>>>
>>>>>>>>>>                struct rb_root_cached  va;
>>>>>>>>>>
>>>>>>>>>>             @@ -240,6 +247,7 @@ struct amdgpu_vm {
>>>>>>>>>>
>>>>>>>>>>                struct ttm_lru_bulk_move lru_bulk_move;
>>>>>>>>>>
>>>>>>>>>>                /* mark whether can do the bulk move */
>>>>>>>>>>
>>>>>>>>>>                bool                   bulk_moveable;
>>>>>>>>>>
>>>>>>>>>>             +  struct amdgpu_retryfault_hashtable *fault_hash;
>>>>>>>>>>
>>>>>>>>>>              };
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>              struct amdgpu_vm_manager {
>>>>>>>>>>
>>>>>>>>>>             @@ -355,4 +363,8 @@ void
>>>>>>>>>> amdgpu_vm_set_task_info(struct
>>>>>>>>>> amdgpu_vm *vm);
>>>>>>>>>>
>>>>>>>>>>              void amdgpu_vm_move_to_lru_tail(struct amdgpu_device
>>>>>>>>>> *adev,
>>>>>>>>>>
>>>>>>>>>>                                       struct amdgpu_vm *vm);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             +int amdgpu_vm_add_fault(struct
>>>>>>>>>> amdgpu_retryfault_hashtable *fault_hash, u64 key);
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +void amdgpu_vm_clear_fault(struct
>>>>>>>>>> amdgpu_retryfault_hashtable *fault_hash, u64 key);
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>              #endif
>>>>>>>>>>
>>>>>>>>>>             diff --git a/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
>>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
>>>>>>>>>>
>>>>>>>>>>             index 5ae5ed2..acbe5a7 100644
>>>>>>>>>>
>>>>>>>>>>             --- a/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
>>>>>>>>>>
>>>>>>>>>>             +++ b/drivers/gpu/drm/amd/amdgpu/vega10_ih.c
>>>>>>>>>>
>>>>>>>>>>             @@ -265,35 +265,36 @@ static bool
>>>>>>>>>> vega10_ih_prescreen_iv(struct amdgpu_device *adev)
>>>>>>>>>>
>>>>>>>>>>                        return true;
>>>>>>>>>>
>>>>>>>>>>                }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             -  addr = ((u64)(dw5 & 0xf) << 44) | ((u64)dw4 << 12);
>>>>>>>>>>
>>>>>>>>>>             -  key = AMDGPU_VM_FAULT(pasid, addr);
>>>>>>>>>>
>>>>>>>>>>             -  r = amdgpu_ih_add_fault(adev, key);
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>             -  /* Hash table is full or the fault is already being
>>>>>>>>>> processed,
>>>>>>>>>>
>>>>>>>>>>             -   * ignore further page faults
>>>>>>>>>>
>>>>>>>>>>             -   */
>>>>>>>>>>
>>>>>>>>>>             -  if (r != 0)
>>>>>>>>>>
>>>>>>>>>>             -          goto ignore_iv;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>                /* Track retry faults in per-VM fault FIFO. */
>>>>>>>>>>
>>>>>>>>>>                spin_lock(&adev->vm_manager.pasid_lock);
>>>>>>>>>>
>>>>>>>>>>                vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
>>>>>>>>>>
>>>>>>>>>>             +  addr = ((u64)(dw5 & 0xf) << 44) | ((u64)dw4 << 12);
>>>>>>>>>>
>>>>>>>>>>             +  key = AMDGPU_VM_FAULT(pasid, addr);
>>>>>>>>>>
>>>>>>>>>>                if (!vm) {
>>>>>>>>>>
>>>>>>>>>>                        /* VM not found, process it normally */
>>>>>>>>>>
>>>>>>>>>> spin_unlock(&adev->vm_manager.pasid_lock);
>>>>>>>>>>
>>>>>>>>>>             -          amdgpu_ih_clear_fault(adev, key);
>>>>>>>>>>
>>>>>>>>>>                        return true;
>>>>>>>>>>
>>>>>>>>>>             +  } else {
>>>>>>>>>>
>>>>>>>>>>             +          r = amdgpu_vm_add_fault(vm->fault_hash,
>>>>>>>>>> key);
>>>>>>>>>>
>>>>>>>>>>             +
>>>>>>>>>>
>>>>>>>>>>             +          /* Hash table is full or the fault is
>>>>>>>>>> already
>>>>>>>>>> being processed,
>>>>>>>>>>
>>>>>>>>>>             +           * ignore further page faults
>>>>>>>>>>
>>>>>>>>>>             +           */
>>>>>>>>>>
>>>>>>>>>>             +          if (r != 0) {
>>>>>>>>>>
>>>>>>>>>>             + spin_unlock(&adev->vm_manager.pasid_lock);
>>>>>>>>>>
>>>>>>>>>>             +                  goto ignore_iv;
>>>>>>>>>>
>>>>>>>>>>             +          }
>>>>>>>>>>
>>>>>>>>>>                }
>>>>>>>>>>
>>>>>>>>>>                /* No locking required with single writer and
>>>>>>>>>> single
>>>>>>>>>> reader */
>>>>>>>>>>
>>>>>>>>>>                r = kfifo_put(&vm->faults, key);
>>>>>>>>>>
>>>>>>>>>>                if (!r) {
>>>>>>>>>>
>>>>>>>>>>                        /* FIFO is full. Ignore it until there is
>>>>>>>>>> space */
>>>>>>>>>>
>>>>>>>>>>             +          amdgpu_vm_clear_fault(vm->fault_hash, key);
>>>>>>>>>>
>>>>>>>>>> spin_unlock(&adev->vm_manager.pasid_lock);
>>>>>>>>>>
>>>>>>>>>>             -          amdgpu_ih_clear_fault(adev, key);
>>>>>>>>>>
>>>>>>>>>>                        goto ignore_iv;
>>>>>>>>>>
>>>>>>>>>>                }
>>>>>>>>>>
>>>>>>>>>>             - spin_unlock(&adev->vm_manager.pasid_lock);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             + spin_unlock(&adev->vm_manager.pasid_lock);
>>>>>>>>>>
>>>>>>>>>>                /* It's the first fault for this address,
>>>>>>>>>> process it
>>>>>>>>>> normally */
>>>>>>>>>>
>>>>>>>>>>                return true;
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             @@ -386,14 +387,6 @@ static int vega10_ih_sw_init(void
>>>>>>>>>> *handle)
>>>>>>>>>>
>>>>>>>>>>                adev->irq.ih.use_doorbell = true;
>>>>>>>>>>
>>>>>>>>>>                adev->irq.ih.doorbell_index = AMDGPU_DOORBELL64_IH
>>>>>>>>>> << 1;
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             -  adev->irq.ih.faults =
>>>>>>>>>> kmalloc(sizeof(*adev->irq.ih.faults), GFP_KERNEL);
>>>>>>>>>>
>>>>>>>>>>             -  if (!adev->irq.ih.faults)
>>>>>>>>>>
>>>>>>>>>>             -          return -ENOMEM;
>>>>>>>>>>
>>>>>>>>>>             - INIT_CHASH_TABLE(adev->irq.ih.faults->hash,
>>>>>>>>>>
>>>>>>>>>>             -                   AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
>>>>>>>>>>
>>>>>>>>>>             - spin_lock_init(&adev->irq.ih.faults->lock);
>>>>>>>>>>
>>>>>>>>>>             -  adev->irq.ih.faults->count = 0;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>                r = amdgpu_irq_init(adev);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>                return r;
>>>>>>>>>>
>>>>>>>>>>             @@ -406,9 +399,6 @@ static int vega10_ih_sw_fini(void
>>>>>>>>>> *handle)
>>>>>>>>>>
>>>>>>>>>>                amdgpu_irq_fini(adev);
>>>>>>>>>>
>>>>>>>>>>                amdgpu_ih_ring_fini(adev);
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>             -  kfree(adev->irq.ih.faults);
>>>>>>>>>>
>>>>>>>>>>             -  adev->irq.ih.faults = NULL;
>>>>>>>>>>
>>>>>>>>>>             -
>>>>>>>>>>
>>>>>>>>>>                return 0;
>>>>>>>>>>
>>>>>>>>>>              }
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>         _______________________________________________
>>>>>>>>>>
>>>>>>>>>>         amd-gfx mailing list
>>>>>>>>>>
>>>>>>>>>>         amd-gfx at lists.freedesktop.org
>>>>>>>>>> <mailto:amd-gfx at lists.freedesktop.org>
>>>>>>>>>>
>>>>>>>>>>         https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> amd-gfx mailing list
>>>>>>>>> amd-gfx at lists.freedesktop.org
>>>>>>>>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>>>>>>> _______________________________________________
>>>>>>> amd-gfx mailing list
>>>>>>> amd-gfx at lists.freedesktop.org
>>>>>>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>>>>> _______________________________________________
>>>>> amd-gfx mailing list
>>>>> amd-gfx at lists.freedesktop.org
>>>>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx



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