[PATCH v3 1/2] drm/amdgpu: Adding db_size to get doorbell absolute offset

From: Arvind Yadav
Date: Wed Oct 04 2023 - 12:17:40 EST


Here, passing db_size in byte to find the doorbell's
absolute offset for both 32-bit and 64-bit doorbell sizes.
So that doorbell offset will be aligned based on the doorbell
size.

v3:
- Adding db_size as parameter to get db absolute offset.

Cc: Christian Koenig <christian.koenig@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxx>
Signed-off-by: Arvind Yadav <Arvind.Yadav@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h | 5 +++--
drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c | 13 +++++++++----
2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
index 09f6727e7c73..4a8b33f55f6b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h
@@ -357,8 +357,9 @@ int amdgpu_doorbell_init(struct amdgpu_device *adev);
void amdgpu_doorbell_fini(struct amdgpu_device *adev);
int amdgpu_doorbell_create_kernel_doorbells(struct amdgpu_device *adev);
uint32_t amdgpu_doorbell_index_on_bar(struct amdgpu_device *adev,
- struct amdgpu_bo *db_bo,
- uint32_t doorbell_index);
+ struct amdgpu_bo *db_bo,
+ uint32_t doorbell_index,
+ uint32_t db_size);

#define RDOORBELL32(index) amdgpu_mm_rdoorbell(adev, (index))
#define WDOORBELL32(index, v) amdgpu_mm_wdoorbell(adev, (index), (v))
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
index da4be0bbb446..6690f5a72f4d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c
@@ -114,19 +114,24 @@ void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v)
* @adev: amdgpu_device pointer
* @db_bo: doorbell object's bo
* @db_index: doorbell relative index in this doorbell object
+ * @db_size: doorbell size is in byte
*
* returns doorbell's absolute index in BAR
*/
uint32_t amdgpu_doorbell_index_on_bar(struct amdgpu_device *adev,
- struct amdgpu_bo *db_bo,
- uint32_t doorbell_index)
+ struct amdgpu_bo *db_bo,
+ uint32_t doorbell_index,
+ uint32_t db_size)
{
int db_bo_offset;

db_bo_offset = amdgpu_bo_gpu_offset_no_check(db_bo);

- /* doorbell index is 32 bit but doorbell's size is 64-bit, so *2 */
- return db_bo_offset / sizeof(u32) + doorbell_index * 2;
+ /* doorbell index is 32 bit but doorbell's size can be 32 bit
+ * or 64 bit, so *db_size(in byte)/4 for alignment.
+ */
+ return db_bo_offset / sizeof(u32) + doorbell_index *
+ DIV_ROUND_UP(db_size, 4);
}

/**
--
2.34.1