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".
(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.
> */
