From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Maxime Chevallier <maxime.chevallier@bootlin.com>
Cc: linux-arch@vger.kernel.org, Olav Kongas <ok@artecdesign.ee>,
Gavin Li <git@thegavinli.com>,
linuxppc-dev@lists.ozlabs.org,
Mathias Nyman <mathias.nyman@intel.com>,
Geoff Levand <geoff@infradead.org>,
Fabio Estevam <festevam@gmail.com>,
Sascha Hauer <s.hauer@pengutronix.de>,
linux-usb@vger.kernel.org, Michal Simek <michal.simek@xilinx.com>,
linux-kernel@vger.kernel.org, Tony Prisk <linux@prisktech.co.nz>,
iommu@lists.linux-foundation.org,
Alan Stern <stern@rowland.harvard.edu>,
NXP Linux Team <linux-imx@nxp.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Minas Harutyunyan <hminas@synopsys.com>,
Shawn Guo <shawnguo@kernel.org>, Bin Liu <b-liu@ti.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 6/6] driver core: initialize a default DMA mask for platform device
Date: Wed, 14 Aug 2019 16:49:13 +0100 [thread overview]
Message-ID: <fbea6e6d-7721-b51d-0501-582e8446e9c9@arm.com> (raw)
In-Reply-To: <20190811080520.21712-7-hch@lst.de>
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;
>
>
next prev parent reply other threads:[~2019-08-14 15:49 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-11 8:05 next take at setting up a dma mask by default for platform devices Christoph Hellwig
2019-08-11 8:05 ` [PATCH 1/6] usb: don't create dma pools for HCDs with a localmem_pool Christoph Hellwig
2019-08-11 8:05 ` [PATCH 2/6] usb: add a hcd_uses_dma helper Christoph Hellwig
2019-08-11 8:05 ` [PATCH 3/6] usb: add a HCD_DMA flag instead of guestimating DMA capabilities Christoph Hellwig
2019-08-12 11:57 ` Christoph Hellwig
2019-08-11 8:05 ` [PATCH 4/6] usb/max3421: remove the dummy {un,}map_urb_for_dma methods Christoph Hellwig
2019-08-11 8:05 ` [PATCH 5/6] dma-mapping: remove is_device_dma_capable Christoph Hellwig
2019-08-11 8:05 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
2019-08-14 15:49 ` Robin Murphy [this message]
2019-08-15 13:32 ` Christoph Hellwig
2019-08-15 13:03 ` Greg Kroah-Hartman
2019-08-15 13:38 ` Christoph Hellwig
2019-08-15 14:05 ` Greg Kroah-Hartman
2019-08-15 13:23 ` next take at setting up a dma mask by default for platform devices Greg Kroah-Hartman
2019-08-15 13:25 ` Christoph Hellwig
2019-08-15 14:05 ` Greg Kroah-Hartman
2019-08-15 14:39 ` Alan Stern
2019-08-16 6:24 next take at setting up a dma mask by default for platform devices v2 Christoph Hellwig
2019-08-16 6:24 ` [PATCH 6/6] driver core: initialize a default DMA mask for platform device Christoph Hellwig
2019-08-16 7:39 ` Geert Uytterhoeven
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