On 2023-03-30 09:42, Luben Tuikov wrote:
> On 2023-03-29 11:47, Shashank Sharma wrote:
>> From: Shashank Sharma <contactshashanksharma@xxxxxxxxx>
>>
>> This patch adds helper functions to create and free doorbell
>> pages for kernel objects.
>>
>> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
>> Cc: Christian Koenig <christian.koenig@xxxxxxx>
>> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxx>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h | 41 ++++++++++++++++
>> .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c | 49 +++++++++++++++++++
>> 2 files changed, 90 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
>> index f9c3b77bf65d..6581b78fe438 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
>> @@ -27,6 +27,24 @@
>> /*
>> * GPU doorbell structures, functions & helpers
>> */
>> +
>> +/* Structure to hold doorbell pages from PCI doorbell BAR */
>> +struct amdgpu_doorbell_obj {
>
> In the comment you say "Structure to hold ...";
> it is a C structure, but then in the name of a function we see "obj".
I mean here " in the name of the structure we see ..."
Regards,
Luben
> (Object is something which is defined like in memory, i.e. it exists, not
> something which is only declared.)
> This is just a declaration of a structure, not an object per se.
> I'd call it "struct amdgpu_doorbell_struct" or just "struct amdgpu_doorbell".
>
> Then in the definition, you can call it an object/objects, if you'd like,
> like "struct amdgpu_doorbell *doorb_object[];" then you can say
> "db = doorb_object[i]";
>
> Regards,
> Luben
>
>> + struct amdgpu_bo *bo;
>> + uint64_t gpu_addr;
>> + uint32_t *cpu_addr;
>> + uint32_t size;
>> +
>> + /* First index in this object */
>> + uint32_t start;
>> +
>> + /* Last index in this object */
>> + uint32_t end;
>> +
>> + /* bitmap for dynamic doorbell allocation from this object */
>> + unsigned long *doorbell_bitmap;
>> +};
>> +
>> struct amdgpu_doorbell {
>> /* doorbell mmio */
>> resource_size_t base;
>> @@ -328,6 +346,29 @@ int amdgpu_device_doorbell_init(struct amdgpu_device *adev);
>> */
>> void amdgpu_device_doorbell_fini(struct amdgpu_device *adev);
>>
>> +/**
>> + * amdgpu_doorbell_free_page - Free a doorbell page
>> + *
>> + * @adev: amdgpu_device pointer
>> + *
>> + * @db_age: previously allocated doobell page details
>> + *
>> + */
>> +void amdgpu_doorbell_free_page(struct amdgpu_device *adev,
>> + struct amdgpu_doorbell_obj *db_obj);
>> +
>> +/**
>> + * amdgpu_doorbell_alloc_page - create a page from doorbell pool
>> + *
>> + * @adev: amdgpu_device pointer
>> + *
>> + * @db_age: doobell page structure to fill details with
>> + *
>> + * returns 0 on success, else error number
>> + */
>> +int amdgpu_doorbell_alloc_page(struct amdgpu_device *adev,
>> + struct amdgpu_doorbell_obj *db_obj);
>> +
>> #define RDOORBELL32(index) amdgpu_mm_rdoorbell(adev, (index))
>> #define WDOORBELL32(index, v) amdgpu_mm_wdoorbell(adev, (index), (v))
>> #define RDOORBELL64(index) amdgpu_mm_rdoorbell64(adev, (index))
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
>> index 1aea92363fd3..8be15b82b545 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
>> @@ -111,6 +111,55 @@ void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v)
>> }
>> }
>>
>> +/**
>> + * amdgpu_doorbell_free_page - Free a doorbell page
>> + *
>> + * @adev: amdgpu_device pointer
>> + *
>> + * @db_age: previously allocated doobell page details
>> + *
>> + */
>> +void amdgpu_doorbell_free_page(struct amdgpu_device *adev,
>> + struct amdgpu_doorbell_obj *db_obj)
>> +{
>> + amdgpu_bo_free_kernel(&db_obj->bo,
>> + &db_obj->gpu_addr,
>> + (void **)&db_obj->cpu_addr);
>> +
>> +}
>> +
>> +/**
>> + * amdgpu_doorbell_alloc_page - create a page from doorbell pool
>> + *
>> + * @adev: amdgpu_device pointer
>> + *
>> + * @db_age: doobell page structure to fill details with
>> + *
>> + * returns 0 on success, else error number
>> + */
>> +int amdgpu_doorbell_alloc_page(struct amdgpu_device *adev,
>> + struct amdgpu_doorbell_obj *db_obj)
>> +{
>> + int r;
>> +
>> + db_obj->size = ALIGN(db_obj->size, PAGE_SIZE);
>> +
>> + r = amdgpu_bo_create_kernel(adev,
>> + db_obj->size,
>> + PAGE_SIZE,
>> + AMDGPU_GEM_DOMAIN_DOORBELL,
>> + &db_obj->bo,
>> + &db_obj->gpu_addr,
>> + (void **)&db_obj->cpu_addr);
>> +
>> + if (r) {
>> + DRM_ERROR("Failed to create doorbell BO, err=%d\n", r);
>> + return r;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> /*
>> * GPU doorbell aperture helpers function.
>> */
>
