[PATCH 5/6] drm/amdgpu: implement grab dedicated vmid V2

[Christian König]

Am 27.04.2017 um 06:42 schrieb zhoucm1:
>
>
> On 2017年04月27日 10:52, Zhang, Jerry (Junwei) wrote:
>> On 04/26/2017 07:10 PM, Chunming Zhou wrote:
>>> v2: move sync waiting only when flush needs
>>>
>>> Change-Id: I64da2701c9fdcf986afb90ba1492a78d5bef1b6c
>>> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
>>> ---
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 61 
>>> ++++++++++++++++++++++++++++++++++
>>>   1 file changed, 61 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>> index 214ac50..bce7701 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>>> @@ -402,6 +402,63 @@ static bool 
>>> amdgpu_vm_dedicated_vmid_ready(struct amdgpu_vm *vm, unsigned vmhub)
>>>       return !!vm->dedicated_vmid[vmhub];
>>>   }
>>>
>>> +static int amdgpu_vm_grab_dedicated_vmid(struct amdgpu_vm *vm,
>>> +                     struct amdgpu_ring *ring,
>>> +                     struct amdgpu_sync *sync,
>>> +                     struct fence *fence,
>>> +                     struct amdgpu_job *job)
>>> +{
>>> +    struct amdgpu_device *adev = ring->adev;
>>> +    unsigned vmhub = ring->funcs->vmhub;
>>> +    struct amdgpu_vm_id *id = vm->dedicated_vmid[vmhub];
>>> +    struct amdgpu_vm_id_manager *id_mgr = 
>>> &adev->vm_manager.id_mgr[vmhub];
>>> +    struct fence *updates = sync->last_vm_update;
>>> +    int r = 0;
>>> +    struct fence *flushed, *tmp;
>>> +    bool needs_flush = false;
>>> +
>>> +    mutex_lock(&id_mgr->lock);
>>> +    if (amdgpu_vm_had_gpu_reset(adev, id))
>>> +        needs_flush = true;
>>> +
>>> +    flushed  = id->flushed_updates;
>>> +    if (updates && (!flushed || updates->context != 
>>> flushed->context ||
>>> +            fence_is_later(updates, flushed)))
>>> +        needs_flush = true;
>>
>> Just question:
>> Do we need to consider concurrent flush for Vega10 like grab id func?
> Christian has pointed that old asic has hardware bug.

Which is fixed for Vega10, on that hardware concurrent flushing works fine.

It's just that Tonga/Fiji have a real problem with that and for 
CIK/Polaris it's more a subtle one which is hard to trigger.

Regards,
Christian.

>
> Regards,
> David Zhou
>>
>> Jerry
>>
>>> +    if (needs_flush) {
>>> +        tmp = amdgpu_sync_get_fence(&id->active);
>>> +        if (tmp) {
>>> +            r = amdgpu_sync_fence(adev, sync, tmp);
>>> +            fence_put(tmp);
>>> +            mutex_unlock(&id_mgr->lock);
>>> +            return r;
>>> +        }
>>> +    }
>>> +
>>> +    /* Good we can use this VMID. Remember this submission as
>>> +    * user of the VMID.
>>> +    */
>>> +    r = amdgpu_sync_fence(ring->adev, &id->active, fence);
>>> +    if (r)
>>> +        goto out;
>>> +
>>> +    if (updates && (!flushed || updates->context != 
>>> flushed->context ||
>>> +            fence_is_later(updates, flushed))) {
>>> +        fence_put(id->flushed_updates);
>>> +        id->flushed_updates = fence_get(updates);
>>> +    }
>>> +    id->pd_gpu_addr = job->vm_pd_addr;
>>> +    id->current_gpu_reset_count = 
>>> atomic_read(&adev->gpu_reset_counter);
>>> +    atomic64_set(&id->owner, vm->client_id);
>>> +    job->vm_needs_flush = needs_flush;
>>> +
>>> +    job->vm_id = id - id_mgr->ids;
>>> +    trace_amdgpu_vm_grab_id(vm, ring, job);
>>> +out:
>>> +    mutex_unlock(&id_mgr->lock);
>>> +    return r;
>>> +}
>>> +
>>>   /**
>>>    * amdgpu_vm_grab_id - allocate the next free VMID
>>>    *
>>> @@ -426,6 +483,10 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, 
>>> struct amdgpu_ring *ring,
>>>       unsigned i;
>>>       int r = 0;
>>>
>>> +    if (amdgpu_vm_dedicated_vmid_ready(vm, vmhub))
>>> +        return amdgpu_vm_grab_dedicated_vmid(vm, ring, sync,
>>> +                             fence, job);
>>> +
>>>       fences = kmalloc_array(sizeof(void *), id_mgr->num_ids, 
>>> GFP_KERNEL);
>>>       if (!fences)
>>>           return -ENOMEM;
>>>
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>
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