[PATCH] drm/amdkfd: Use the correct wptr size

[Lazar, Lijo]

On 11/28/2024 5:43 AM, Felix Kuehling wrote:
> 
> On 2024-11-18 00:34, Lijo Lazar wrote:
>> Write pointer could be 32-bit or 64-bit. Use the correct size during
>> initialization.
>>
>> Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c b/drivers/
>> gpu/drm/amd/amdkfd/kfd_kernel_queue.c
>> index 4843dcb9a5f7..d6037577c532 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_kernel_queue.c
>> @@ -125,7 +125,7 @@ static bool kq_initialize(struct kernel_queue *kq,
>> struct kfd_node *dev,
>>         memset(kq->pq_kernel_addr, 0, queue_size);
>>       memset(kq->rptr_kernel, 0, sizeof(*kq->rptr_kernel));
>> -    memset(kq->wptr_kernel, 0, sizeof(*kq->wptr_kernel));
>> +    memset(kq->wptr_kernel, 0, dev->kfd->device_info.doorbell_size);
> 
> It would be safer and cleaner to just initialize kq->wptr64_kernel,
> which is always 64 bit and aliases kq->wptr_kernel.
> 

It's done this way because of aliasing. The size requested is
doorbell_size which could be 4 or 8 bytes.

By safer, do you mean to have an if..else check in case the aliasing is
taken out?

Thanks,
Lijo

> Regards,
>   Felix
> 
> 
> 
>>         prop.queue_size = queue_size;
>>       prop.is_interop = false;