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

[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.

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