On Sun, Aug 11, 2019 at 10:05:20AM +0200, 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
> 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.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> 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)
> +{
> + 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);
> +};
> +
> /**
> * 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;
Why is the dma_mask in 'struct device' which is part of this structure,
not sufficient here? Shouldn't the "platform" be setting that up
correctly already in the "archdata" type callback?
confused,
greg k-h
