Re: [PATCH v4 1/2] ARM: dma-mapping: Set proper DMA ops in arm_iommu_detach_device()

Russell King - ARM Linux
2018-07-02T15:23:55Z

On Mon, Jul 02, 2018 at 01:53:17PM +0200, Thierry Reding wrote:
> On Wed, May 30, 2018 at 04:06:24PM +0200, Thierry Reding wrote:
> > From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >
> > Instead of setting the DMA ops pointer to NULL, set the correct,
> > non-IOMMU ops depending on the device's coherency setting.
> >
> > Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > ---
> > Changes in v4:
> > - new patch to fix existing arm_iommu_detach_device() to do what we need
> >
> > arch/arm/mm/dma-mapping.c | 12 ++++++------
> > 1 file changed, 6 insertions(+), 6 deletions(-)
>
> Christoph, Russell,
>
> could either of you provide an Acked-by for this? I think it makes the
> most sense for Ben to pick this up into the Nouveau tree along with
> patch 2/2.

Looks fine to me.

Acked-by: Russell King <rmk+kernel-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org>

Thanks.

>
> Thierry
>
> > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> > index af27f1c22d93..87a0037574e4 100644
> > --- a/arch/arm/mm/dma-mapping.c
> > +++ b/arch/arm/mm/dma-mapping.c
> > @@ -1151,6 +1151,11 @@ int arm_dma_supported(struct device *dev, u64 mask)
> > return __dma_supported(dev, mask, false);
> > }
> >
> > +static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
> > +{
> > + return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
> > +}
> > +
> > #ifdef CONFIG_ARM_DMA_USE_IOMMU
> >
> > static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
> > @@ -2296,7 +2301,7 @@ void arm_iommu_detach_device(struct device *dev)
> > iommu_detach_device(mapping->domain, dev);
> > kref_put(&mapping->kref, release_iommu_mapping);
> > to_dma_iommu_mapping(dev) = NULL;
> > - set_dma_ops(dev, NULL);
> > + set_dma_ops(dev, arm_get_dma_map_ops(dev->archdata.dma_coherent));
> >
> > pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
> > }
> > @@ -2357,11 +2362,6 @@ static void arm_teardown_iommu_dma_ops(struct device *dev) { }
> >
> > #endif /* CONFIG_ARM_DMA_USE_IOMMU */
> >
> > -static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
> > -{
> > - return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
> > -}
> > -
> > void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
> > const struct iommu_ops *iommu, bool coherent)
> > {
> > --
> > 2.17.0
> >

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