Messages in this thread | | | Subject | Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device | From | Robin Murphy <> | Date | Wed, 14 Aug 2019 16:49:13 +0100 |
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On 11/08/2019 09:05, Christoph Hellwig wrote: > We still treat devices without a DMA mask as defaulting to 32-bits for > both mask, but a few releases ago we've started warning about such > cases, as they require special cases to work around this sloppyness. > Add a dma_mask field to struct platform_object so that we can initialize
s/object/device/
> the dma_mask pointer in struct device and initialize both masks to > 32-bits by default. Architectures can still override this in > arch_setup_pdev_archdata if needed. > > Note that the code looks a little odd with the various conditionals > because we have to support platform_device structures that are > statically allocated.
This would be a good point to also get rid of the long-standing bodge in platform_device_register_full().
> Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/base/platform.c | 15 +++++++++++++-- > include/linux/platform_device.h | 1 + > 2 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index ec974ba9c0c4..b216fcb0a8af 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -264,6 +264,17 @@ struct platform_object { > char name[]; > }; > > +static void setup_pdev_archdata(struct platform_device *pdev)
Bikeshed: painting the generic DMA API properties as "archdata" feels a bit off-target :/
> +{ > + if (!pdev->dev.coherent_dma_mask) > + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); > + if (!pdev->dma_mask) > + pdev->dma_mask = DMA_BIT_MASK(32); > + if (!pdev->dev.dma_mask) > + pdev->dev.dma_mask = &pdev->dma_mask; > + arch_setup_pdev_archdata(pdev);
AFAICS m68k's implementation of that arch hook becomes entirely redundant after this change, so may as well go. That would just leave powerpc's actual archdata, which at a glance looks like it could probably be cleaned up with not *too* much trouble.
Robin.
> +}; > + > /** > * platform_device_put - destroy a platform device > * @pdev: platform device to free > @@ -310,7 +321,7 @@ struct platform_device *platform_device_alloc(const char *name, int id) > pa->pdev.id = id; > device_initialize(&pa->pdev.dev); > pa->pdev.dev.release = platform_device_release; > - arch_setup_pdev_archdata(&pa->pdev); > + setup_pdev_archdata(&pa->pdev); > } > > return pa ? &pa->pdev : NULL; > @@ -512,7 +523,7 @@ EXPORT_SYMBOL_GPL(platform_device_del); > int platform_device_register(struct platform_device *pdev) > { > device_initialize(&pdev->dev); > - arch_setup_pdev_archdata(pdev); > + setup_pdev_archdata(pdev); > return platform_device_add(pdev); > } > EXPORT_SYMBOL_GPL(platform_device_register); > diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h > index 9bc36b589827..a2abde2aef25 100644 > --- a/include/linux/platform_device.h > +++ b/include/linux/platform_device.h > @@ -24,6 +24,7 @@ struct platform_device { > int id; > bool id_auto; > struct device dev; > + u64 dma_mask; > u32 num_resources; > struct resource *resource; > >
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