[PATCH v2 5/8] drm/amdgpu: accommodate DOMAIN/PL_DOORBELL

Christian König christian.koenig at amd.com
Wed Feb 15 13:36:09 UTC 2023


Am 15.02.23 um 14:32 schrieb Shashank Sharma:
>
> On 15/02/2023 07:17, Christian König wrote:
>> Am 14.02.23 um 20:24 schrieb Shashank Sharma:
>>>
>>> On 14/02/2023 19:31, Christian König wrote:
>>>> Am 14.02.23 um 17:15 schrieb Shashank Sharma:
>>>>> From: Alex Deucher <alexander.deucher at amd.com>
>>>>>
>>>>> This patch adds changes:
>>>>> - to accommodate the new GEM domain DOORBELL
>>>>> - to accommodate the new TTM PL DOORBELL
>>>>>
>>>>> to manage doorbell allocations as GEM Objects.
>>>>>
>>>>> V2: Addressed reviwe comments from Christian
>>>>>      - drop the doorbell changes for pinning/unpinning
>>>>>      - drop the doorbell changes for dma-buf map
>>>>>      - drop the doorbell changes for sgt
>>>>>      - no need to handle TTM_PL_FLAG_CONTIGUOUS for doorbell
>>>>>
>>>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>>>>> Signed-off-by: Shashank Sharma <shashank.sharma at amd.com>
>>>>> ---
>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 11 ++++++++++-
>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 11 ++++++++++-
>>>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h    |  1 +
>>>>>   3 files changed, 21 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c 
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>>>>> index b48c9fd60c43..ff9979fecfd2 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>>>>> @@ -147,6 +147,14 @@ void amdgpu_bo_placement_from_domain(struct 
>>>>> amdgpu_bo *abo, u32 domain)
>>>>>           c++;
>>>>>       }
>>>>>   +    if (domain & AMDGPU_GEM_DOMAIN_DOORBELL) {
>>>>> +        places[c].fpfn = 0;
>>>>> +        places[c].lpfn = 0;
>>>>> +        places[c].mem_type = AMDGPU_PL_DOORBELL;
>>>>> +        places[c].flags = 0;
>>>>> +        c++;
>>>>> +    }
>>>>> +
>>>>
>>>> Mhm, do we need to increase AMDGPU_BO_MAX_PLACEMENTS?
>>>>
>>>> I think the answer is *no* since mixing DOORBELL with CPU, GTT or 
>>>> VRAM placement doesn't make sense, but do we enforce that somewhere?
>>> I am not sure why do we need that ?
>>
>> Userspace could otherwise specify DOORBEEL|CPU|GTT|VRAM as placement 
>> which would overrun the array and be illegal.
>
> Now when I understand this, how can we enforce this ? A size check 
> that blocks places to go over a certain value, which is fixed for 
> boorbell ?

In amdgpu_bo_create() we should have a check that if GDS, GWS, OA and 
DOORBELL are specified they are specified all alone. In other words 
those domains can't be mixed with anything else.

Christian.

>
>>
>>>>
>>>>>       if (domain & AMDGPU_GEM_DOMAIN_GTT) {
>>>>>           places[c].fpfn = 0;
>>>>>           places[c].lpfn = 0;
>>>>> @@ -466,7 +474,7 @@ static bool amdgpu_bo_validate_size(struct 
>>>>> amdgpu_device *adev,
>>>>>           goto fail;
>>>>>       }
>>>>>   -    /* TODO add more domains checks, such as 
>>>>> AMDGPU_GEM_DOMAIN_CPU */
>>>>> +    /* TODO add more domains checks, such as 
>>>>> AMDGPU_GEM_DOMAIN_CPU,  AMDGPU_GEM_DOMAIN_DOORBELL */
>>>>
>>>> Should we enforce that user space can only allocate 1 page doorbells?
>>>>
>>> Should we add a per-PID basis check ?
>>
>> No, just a check that the allocation size of the doorbell BOs is just 
>> 1 page.
>
> Noted
>
> - Shashank
>
>>
>> Christian.
>>
>>>
>>> - Shashank
>>>
>>>>>       return true;
>>>>>     fail:
>>>>> @@ -1014,6 +1022,7 @@ void amdgpu_bo_unpin(struct amdgpu_bo *bo)
>>>>>       } else if (bo->tbo.resource->mem_type == TTM_PL_TT) {
>>>>>           atomic64_sub(amdgpu_bo_size(bo), &adev->gart_pin_size);
>>>>>       }
>>>>> +
>>>>
>>>> Unrelated change.
>>>
>>> Noted
>>>
>>> - Shashank
>>>
>>>>
>>>> Regards,
>>>> Christian.
>>>>
>>>>>   }
>>>>>     static const char *amdgpu_vram_names[] = {
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>>> index 0e8f580769ab..e9dc24191fc8 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>>> @@ -128,6 +128,7 @@ static void amdgpu_evict_flags(struct 
>>>>> ttm_buffer_object *bo,
>>>>>       case AMDGPU_PL_GDS:
>>>>>       case AMDGPU_PL_GWS:
>>>>>       case AMDGPU_PL_OA:
>>>>> +    case AMDGPU_PL_DOORBELL:
>>>>>           placement->num_placement = 0;
>>>>>           placement->num_busy_placement = 0;
>>>>>           return;
>>>>> @@ -500,9 +501,11 @@ static int amdgpu_bo_move(struct 
>>>>> ttm_buffer_object *bo, bool evict,
>>>>>       if (old_mem->mem_type == AMDGPU_PL_GDS ||
>>>>>           old_mem->mem_type == AMDGPU_PL_GWS ||
>>>>>           old_mem->mem_type == AMDGPU_PL_OA ||
>>>>> +        old_mem->mem_type == AMDGPU_PL_DOORBELL ||
>>>>>           new_mem->mem_type == AMDGPU_PL_GDS ||
>>>>>           new_mem->mem_type == AMDGPU_PL_GWS ||
>>>>> -        new_mem->mem_type == AMDGPU_PL_OA) {
>>>>> +        new_mem->mem_type == AMDGPU_PL_OA ||
>>>>> +        new_mem->mem_type == AMDGPU_PL_DOORBELL) {
>>>>>           /* Nothing to save here */
>>>>>           ttm_bo_move_null(bo, new_mem);
>>>>>           goto out;
>>>>> @@ -586,6 +589,11 @@ static int amdgpu_ttm_io_mem_reserve(struct 
>>>>> ttm_device *bdev,
>>>>>           mem->bus.offset += adev->gmc.vram_aper_base;
>>>>>           mem->bus.is_iomem = true;
>>>>>           break;
>>>>> +    case AMDGPU_PL_DOORBELL:
>>>>> +        mem->bus.offset = mem->start << PAGE_SHIFT;
>>>>> +        mem->bus.offset += adev->doorbell.doorbell_aper_base;
>>>>> +        mem->bus.is_iomem = true;
>>>>> +        break;
>>>>>       default:
>>>>>           return -EINVAL;
>>>>>       }
>>>>> @@ -1267,6 +1275,7 @@ uint64_t amdgpu_ttm_tt_pde_flags(struct 
>>>>> ttm_tt *ttm, struct ttm_resource *mem)
>>>>>           flags |= AMDGPU_PTE_VALID;
>>>>>         if (mem && (mem->mem_type == TTM_PL_TT ||
>>>>> +            mem->mem_type == AMDGPU_PL_DOORBELL ||
>>>>>               mem->mem_type == AMDGPU_PL_PREEMPT)) {
>>>>>           flags |= AMDGPU_PTE_SYSTEM;
>>>>>   diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h 
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>>> index 967b265dbfa1..9cf5d8419965 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>>> @@ -33,6 +33,7 @@
>>>>>   #define AMDGPU_PL_GWS        (TTM_PL_PRIV + 1)
>>>>>   #define AMDGPU_PL_OA        (TTM_PL_PRIV + 2)
>>>>>   #define AMDGPU_PL_PREEMPT    (TTM_PL_PRIV + 3)
>>>>> +#define AMDGPU_PL_DOORBELL    (TTM_PL_PRIV + 4)
>>>>>     #define AMDGPU_GTT_MAX_TRANSFER_SIZE    512
>>>>>   #define AMDGPU_GTT_NUM_TRANSFER_WINDOWS    2
>>>>
>>



More information about the amd-gfx mailing list