[RFC PATCH 2/3] drm/amdgpu/ttm: replace duplicate code with exiting function

[Christian König]

Am 15.07.21 um 11:29 schrieb Lazar, Lijo:
>
>
> On 7/15/2021 2:56 PM, Christian König wrote:
>> Am 15.07.21 um 10:24 schrieb Kevin Wang:
>>> using exiting function to replace duplicate code blocks in
>>> amdgpu_ttm_vram_write().
>>
>> NAK, this should intentionally only use the MM path and not the aper 
>> path.
>>
>
> What about platform configs which don't support HDP?

Good question, I have no idea.

As far as I know the write interface here intentionally uses the 
MM_INDEX/MM_DATA to bypass the HDP cache.

Regards,
Christian.

>
> Thanks,
> Lijo
>
>> But you could use amdgpu_device_mm_access() here now.
>>
>> Christian.
>>
>>>
>>> Signed-off-by: Kevin Wang <kevin1.wang at amd.com>
>>> ---
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 7 +------
>>>   1 file changed, 1 insertion(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> index 2aa2eb5de37a..2c98e4345ad3 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>> @@ -2207,7 +2207,6 @@ static ssize_t amdgpu_ttm_vram_write(struct 
>>> file *f, const char __user *buf,
>>>           return -ENXIO;
>>>       while (size) {
>>> -        unsigned long flags;
>>>           uint32_t value;
>>>           if (*pos >= adev->gmc.mc_vram_size)
>>> @@ -2217,11 +2216,7 @@ static ssize_t amdgpu_ttm_vram_write(struct 
>>> file *f, const char __user *buf,
>>>           if (r)
>>>               return r;
>>> -        spin_lock_irqsave(&adev->mmio_idx_lock, flags);
>>> -        WREG32_NO_KIQ(mmMM_INDEX, ((uint32_t)*pos) | 0x80000000);
>>> -        WREG32_NO_KIQ(mmMM_INDEX_HI, *pos >> 31);
>>> -        WREG32_NO_KIQ(mmMM_DATA, value);
>>> -        spin_unlock_irqrestore(&adev->mmio_idx_lock, flags);
>>> +        amdgpu_device_vram_access(adev, *pos, &value, 4, true);
>>>           result += 4;
>>>           buf += 4;
>>