Messages in this thread | | | From | Marek Szyprowski <> | Subject | RE: How to specify IOMMU'able devices in DT (was: [RFC 0/5] ARM: dma-mapping: New dma_map_ops to control IOVA more precisely) | Date | Mon, 24 Sep 2012 13:14:51 +0200 |
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Hello,
On Monday, September 24, 2012 11:45 AM Hiroshi Doyu wrote:
> On Mon, 24 Sep 2012 11:28:01 +0200 > James Bottomley <James.Bottomley@HansenPartnership.com> wrote: > > > On Mon, 2012-09-24 at 12:04 +0300, Hiroshi Doyu wrote: > > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > > > index a1a7225..9eae3be 100644 > > > --- a/drivers/base/platform.c > > > +++ b/drivers/base/platform.c > > > @@ -21,6 +21,8 @@ > > > #include <linux/slab.h> > > > #include <linux/pm_runtime.h> > > > > > > +#include <asm/dma-iommu.h> > > > + > > > #include "base.h" > > > > > > #define to_platform_driver(drv) (container_of((drv), struct > > > platform_driver, \ > > > @@ -305,8 +307,19 @@ int platform_device_add(struct platform_device > > > *pdev) > > > dev_name(&pdev->dev), dev_name(pdev->dev.parent)); > > > > > > ret = device_add(&pdev->dev); > > > - if (ret == 0) > > > - return ret; > > > + if (ret) > > > + goto failed; > > > + > > > +#ifdef CONFIG_PLATFORM_ENABLE_IOMMU > > > + if (platform_bus_type.map && !pdev->dev.archdata.mapping) { > > > + ret = arm_iommu_attach_device(&pdev->dev, > > > + platform_bus_type.map); > > > + if (ret) > > > + goto failed; > > > > This is horrible ... you're adding an architecture specific callback > > into our generic code; that's really a no-no. If the concept of > > CONFIG_PLATFORM_ENABE_IOMMU is useful to more than just arm, then this > > could become a generic callback. > > As mentioned in the original, this is a heck to explain what is > needed. I am looking for some generic solution for how to specify > IOMMU info for each platform devices. I'm guessing that some other SoC > may have the similar requirements on the above. As you mentioned, this > solution should be a generic, not arch specific.
Please read more about bus notifiers. IMHO a good example is provided in the following thread: http://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg12238.html
Best regards -- Marek Szyprowski Samsung Poland R&D Center
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