Re: [PATCH 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8

2023-09-27 Thread Shashank Sharma



On 27/09/2023 19:27, Felix Kuehling wrote:


[+Mukul]

On 2023-09-27 12:16, Arvind Yadav wrote:

This patch is to adjust the absolute doorbell offset
against the doorbell id considering the doorbell
size of 32/64 bit.

Cc: Christian Koenig
Cc: Alex Deucher
Signed-off-by: Shashank Sharma
Signed-off-by: Arvind Yadav
---
  drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 11 ++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 0d3d538b64eb..c327f7f604d7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -407,7 +407,16 @@ static int allocate_doorbell(struct qcm_process_device 
*qpd,
  
  	q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev->adev,

  
qpd->proc_doorbells,
- 
q->doorbell_id);
+ 0);


Looks like we're now always calling amdgpu_doorbell_index_on_bar with 
the third parameter = 0. So we could remove that parameter. It doesn't 
do us any good and only causes bugs if we use any non-0 value.



Hey Felix,

Actually this was happening because in usermode KFD library the 
doorbell-size is for non-SOC15() hardware is hard coded to 4 bytes.


We added this fix just so that the library code doesn't need to be 
changed, but can still get aligned to kernel code.


GFX Usermode queue code uses this doorbell-index parameter, and it gives 
us the right offset.



Regards

Shashank




+
+   /* Adjust the absolute doorbell offset against the doorbell id 
considering
+* the doorbell size of 32/64 bit.
+*/
+   if (!KFD_IS_SOC15(dev))
+   q->properties.doorbell_off += q->doorbell_id;
+   else
+   q->properties.doorbell_off += q->doorbell_id * 2;


This could be simplified and generalized as

q->properties.doorbell_off += q->doorbell_id * 
dev->kfd->device_info.doorbell_size / 4;


Agree, we can do this simplification.

- Shashank


Regards,
  Felix



+
return 0;
  }
  


Re: [PATCH 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8

2023-09-27 Thread Felix Kuehling

[+Mukul]

On 2023-09-27 12:16, Arvind Yadav wrote:

This patch is to adjust the absolute doorbell offset
against the doorbell id considering the doorbell
size of 32/64 bit.

Cc: Christian Koenig
Cc: Alex Deucher
Signed-off-by: Shashank Sharma
Signed-off-by: Arvind Yadav
---
  drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 11 ++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 0d3d538b64eb..c327f7f604d7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -407,7 +407,16 @@ static int allocate_doorbell(struct qcm_process_device 
*qpd,
  
  	q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev->adev,

  
qpd->proc_doorbells,
- 
q->doorbell_id);
+ 0);


Looks like we're now always calling amdgpu_doorbell_index_on_bar with 
the third parameter = 0. So we could remove that parameter. It doesn't 
do us any good and only causes bugs if we use any non-0 value.




+
+   /* Adjust the absolute doorbell offset against the doorbell id 
considering
+* the doorbell size of 32/64 bit.
+*/
+   if (!KFD_IS_SOC15(dev))
+   q->properties.doorbell_off += q->doorbell_id;
+   else
+   q->properties.doorbell_off += q->doorbell_id * 2;


This could be simplified and generalized as

q->properties.doorbell_off += q->doorbell_id * 
dev->kfd->device_info.doorbell_size / 4;

Regards,
  Felix



+
return 0;
  }
  

Re: [PATCH 1/1] drm/amdkfd: Fix unaligned doorbell absolute offset for gfx8

2023-09-27 Thread Yadav, Arvind

Adding felix.kuehl...@amd.com for review.

Thanks
~Arvind

On 9/27/2023 9:46 PM, Arvind Yadav wrote:

This patch is to adjust the absolute doorbell offset
against the doorbell id considering the doorbell
size of 32/64 bit.

Cc: Christian Koenig 
Cc: Alex Deucher 
Signed-off-by: Shashank Sharma 
Signed-off-by: Arvind Yadav 
---
  drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 11 ++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 0d3d538b64eb..c327f7f604d7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -407,7 +407,16 @@ static int allocate_doorbell(struct qcm_process_device 
*qpd,
  
  	q->properties.doorbell_off = amdgpu_doorbell_index_on_bar(dev->adev,

  
qpd->proc_doorbells,
- 
q->doorbell_id);
+ 0);
+
+   /* Adjust the absolute doorbell offset against the doorbell id 
considering
+* the doorbell size of 32/64 bit.
+*/
+   if (!KFD_IS_SOC15(dev))
+   q->properties.doorbell_off += q->doorbell_id;
+   else
+   q->properties.doorbell_off += q->doorbell_id * 2;
+
return 0;
  }