[PATCH] drm/amdgpu: add print for iommu translation mode

[Christian König]

Am 17.03.23 um 21:04 schrieb Sider, Graham:
> [AMD Official Use Only - General]
>
>
>
>> -----Original Message-----
>> From: Russell, Kent <Kent.Russell at amd.com>
>> Sent: Friday, March 17, 2023 3:58 PM
>> To: Mahfooz, Hamza <Hamza.Mahfooz at amd.com>; Sider, Graham
>> <Graham.Sider at amd.com>; amd-gfx at lists.freedesktop.org
>> Cc: Kuehling, Felix <Felix.Kuehling at amd.com>
>> Subject: RE: [PATCH] drm/amdgpu: add print for iommu translation mode
>>
>> [AMD Official Use Only - General]
>>
>>
>>
>>> -----Original Message-----
>>> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
>>> Hamza Mahfooz
>>> Sent: Friday, March 17, 2023 3:58 PM
>>> To: Sider, Graham <Graham.Sider at amd.com>;
>>> amd-gfx at lists.freedesktop.org
>>> Cc: Kuehling, Felix <Felix.Kuehling at amd.com>
>>> Subject: Re: [PATCH] drm/amdgpu: add print for iommu translation mode
>>>
>>>
>>> On 3/17/23 15:47, Graham Sider wrote:
>>>> Add log to display whether RAM is direct vs DMA mapped.
>>>>
>>>> Signed-off-by: Graham Sider <Graham.Sider at amd.com>
>>> If this information is only useful for debugging purposes, please use
>>> drm_dbg() instead of pr_info().
> It's useful for more than just debug I would say. Just a quick way to grep whether IOMMU is off/pt vs device isolation mode.

Mhm, shouldn't the IOMMU code note that as well?

Christian.

>
> Graham
>
>>>> ---
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 6 +++++-
>>>>    1 file changed, 5 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> index 8bba5e6872a1..8797a9523244 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> @@ -3528,8 +3528,12 @@ static void
>>> amdgpu_device_check_iommu_direct_map(struct amdgpu_device *adev)
>>>>    	struct iommu_domain *domain;
>>>>
>>>>    	domain = iommu_get_domain_for_dev(adev->dev);
>>>> -	if (!domain || domain->type == IOMMU_DOMAIN_IDENTITY)
>>>> +	if (!domain || domain->type == IOMMU_DOMAIN_IDENTITY) {
>>>> +		pr_info("RAM is direct mapped to GPU (not traslated by
>> traslated -> translated
>>
> Thanks, my keyboard keeps skipping the on the 'n' key lately :( time for a clean.
>
> Graham
>
>>   Kent
>>> IOMMU)\n");
>>>>    		adev->ram_is_direct_mapped = true;
>>>> +	} else {
>>>> +		pr_info("RAM is DMA mapped to GPU (translated by
>>> IOMMU)\n");
>>>> +	}
>>>>    }
>>>>
>>>>    static const struct attribute *amdgpu_dev_attributes[] = {
>>> --
>>> Hamza