| Message ID | 20141024154353.GE20534@e104818-lin.cambridge.arm.com |
|---|---|
| State | New |
| Headers | show |
On Fri, 24 Oct 2014, Catalin Marinas wrote: > On Fri, Oct 24, 2014 at 12:39:59PM +0100, Stefano Stabellini wrote: > > On Fri, 24 Oct 2014, Catalin Marinas wrote: > > > I think a better way would be some Xen hook around > > > set_arch_dma_coherent_ops(). Does Xen have its own device tracking > > > structures? If not, you may be able to add another bitfield to the > > > kernel one. > > > > We don't have an additional device tracking struct on Xen. > > I agree that a new bit somewhere would be the best solution, but I am > > not sure where. Maybe in dev_archdata under arm and arm64? After all it > > is already used to keep pointers to dma and coherency related > > structures. > > I was thinking about something like below (maybe with some additional > ARCH_HAS_NONCOHERENT_DMA config for architectures that are always > coherent): > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > index 3b64d0bf5bba..ae399ccbd569 100644 > --- a/drivers/of/platform.c > +++ b/drivers/of/platform.c > @@ -183,6 +183,7 @@ static void of_dma_configure(struct device *dev) > * dma coherent operations. > */ > if (of_dma_is_coherent(dev->of_node)) { > + dev->dma_coherent = 1; > set_arch_dma_coherent_ops(dev); > dev_dbg(dev, "device is dma coherent\n"); > } > diff --git a/include/linux/device.h b/include/linux/device.h > index ce1f21608b16..e00ca876db01 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -796,6 +796,7 @@ struct device { > > bool offline_disabled:1; > bool offline:1; > + bool dma_coherent:1; > }; > > static inline struct device *kobj_to_dev(struct kobject *kobj) > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index d5d388160f42..9c9ba5a5428e 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -78,6 +78,11 @@ static inline int is_device_dma_capable(struct device *dev) > return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE; > } > > +static inline int is_device_dma_coherent(struct device *dev) > +{ > + return dev->dma_coherent; > +} > + > #ifdef CONFIG_HAS_DMA > #include <asm/dma-mapping.h> > #else This is probably the cleanest option. I am going to send it out and see what the comments are. I might still be able to request a backport if it doesn't make 3.18. > > However given the timing constraints I hope you would be OK with the > > suboptimal solution for now and create a common is_dma_coherent function > > in 3.19? > > If you want to push something for 3.18, you could have a temporary > solution but I would prefer a bool or something in the dev_archdata > structure. Another untested patch: > > diff --git a/arch/arm64/include/asm/device.h b/arch/arm64/include/asm/device.h > index cf98b362094b..243ef256b8c9 100644 > --- a/arch/arm64/include/asm/device.h > +++ b/arch/arm64/include/asm/device.h > @@ -21,6 +21,7 @@ struct dev_archdata { > #ifdef CONFIG_IOMMU_API > void *iommu; /* private IOMMU data */ > #endif > + bool dma_coherent; > }; > > struct pdev_archdata { > diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h > index adeae3f6f0fc..b6bc4c268878 100644 > --- a/arch/arm64/include/asm/dma-mapping.h > +++ b/arch/arm64/include/asm/dma-mapping.h > @@ -54,11 +54,17 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops) > > static inline int set_arch_dma_coherent_ops(struct device *dev) > { > + dev->dev_archdata.dma_coherent = true; > set_dma_ops(dev, &coherent_swiotlb_dma_ops); > return 0; > } > #define set_arch_dma_coherent_ops set_arch_dma_coherent_ops > > +static inline int is_device_dma_coherent(struct device *dev) > +{ > + return dev->dev_archdata.dma_coherent; > +} > + > #include <asm-generic/dma-mapping-common.h> > > static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) > > > This way you don't have to test for swiotlb vs iommu ops (we don't have > the latter yet on arm64 but they are coming). > > -- > Catalin > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On Fri, 24 Oct 2014, Stefano Stabellini wrote: > On Fri, 24 Oct 2014, Catalin Marinas wrote: > > On Fri, Oct 24, 2014 at 12:39:59PM +0100, Stefano Stabellini wrote: > > > On Fri, 24 Oct 2014, Catalin Marinas wrote: > > > > I think a better way would be some Xen hook around > > > > set_arch_dma_coherent_ops(). Does Xen have its own device tracking > > > > structures? If not, you may be able to add another bitfield to the > > > > kernel one. > > > > > > We don't have an additional device tracking struct on Xen. > > > I agree that a new bit somewhere would be the best solution, but I am > > > not sure where. Maybe in dev_archdata under arm and arm64? After all it > > > is already used to keep pointers to dma and coherency related > > > structures. > > > > I was thinking about something like below (maybe with some additional > > ARCH_HAS_NONCOHERENT_DMA config for architectures that are always > > coherent): I don't think that introducing ARCH_HAS_NONCOHERENT_DMA is necessary here. > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > > index 3b64d0bf5bba..ae399ccbd569 100644 > > --- a/drivers/of/platform.c > > +++ b/drivers/of/platform.c > > @@ -183,6 +183,7 @@ static void of_dma_configure(struct device *dev) > > * dma coherent operations. > > */ > > if (of_dma_is_coherent(dev->of_node)) { > > + dev->dma_coherent = 1; > > set_arch_dma_coherent_ops(dev); > > dev_dbg(dev, "device is dma coherent\n"); > > } > > diff --git a/include/linux/device.h b/include/linux/device.h > > index ce1f21608b16..e00ca876db01 100644 > > --- a/include/linux/device.h > > +++ b/include/linux/device.h > > @@ -796,6 +796,7 @@ struct device { > > > > bool offline_disabled:1; > > bool offline:1; > > + bool dma_coherent:1; > > }; > > > > static inline struct device *kobj_to_dev(struct kobject *kobj) > > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > > index d5d388160f42..9c9ba5a5428e 100644 > > --- a/include/linux/dma-mapping.h > > +++ b/include/linux/dma-mapping.h > > @@ -78,6 +78,11 @@ static inline int is_device_dma_capable(struct device *dev) > > return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE; > > } > > > > +static inline int is_device_dma_coherent(struct device *dev) > > +{ > > + return dev->dma_coherent; > > +} > > + > > #ifdef CONFIG_HAS_DMA > > #include <asm/dma-mapping.h> > > #else > > This is probably the cleanest option. I am going to send it out and see > what the comments are. > > I might still be able to request a backport if it doesn't make 3.18. > > > > > However given the timing constraints I hope you would be OK with the > > > suboptimal solution for now and create a common is_dma_coherent function > > > in 3.19? > > > > If you want to push something for 3.18, you could have a temporary > > solution but I would prefer a bool or something in the dev_archdata > > structure. Another untested patch: > > > > diff --git a/arch/arm64/include/asm/device.h b/arch/arm64/include/asm/device.h > > index cf98b362094b..243ef256b8c9 100644 > > --- a/arch/arm64/include/asm/device.h > > +++ b/arch/arm64/include/asm/device.h > > @@ -21,6 +21,7 @@ struct dev_archdata { > > #ifdef CONFIG_IOMMU_API > > void *iommu; /* private IOMMU data */ > > #endif > > + bool dma_coherent; > > }; > > > > struct pdev_archdata { > > diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h > > index adeae3f6f0fc..b6bc4c268878 100644 > > --- a/arch/arm64/include/asm/dma-mapping.h > > +++ b/arch/arm64/include/asm/dma-mapping.h > > @@ -54,11 +54,17 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops) > > > > static inline int set_arch_dma_coherent_ops(struct device *dev) > > { > > + dev->dev_archdata.dma_coherent = true; > > set_dma_ops(dev, &coherent_swiotlb_dma_ops); > > return 0; > > } > > #define set_arch_dma_coherent_ops set_arch_dma_coherent_ops > > > > +static inline int is_device_dma_coherent(struct device *dev) > > +{ > > + return dev->dev_archdata.dma_coherent; > > +} > > + > > #include <asm-generic/dma-mapping-common.h> > > > > static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) > > > > > > This way you don't have to test for swiotlb vs iommu ops (we don't have > > the latter yet on arm64 but they are coming). > > > > -- > > Catalin > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/drivers/of/platform.c b/drivers/of/platform.c index 3b64d0bf5bba..ae399ccbd569 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -183,6 +183,7 @@ static void of_dma_configure(struct device *dev) * dma coherent operations. */ if (of_dma_is_coherent(dev->of_node)) { + dev->dma_coherent = 1; set_arch_dma_coherent_ops(dev); dev_dbg(dev, "device is dma coherent\n"); } diff --git a/include/linux/device.h b/include/linux/device.h index ce1f21608b16..e00ca876db01 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -796,6 +796,7 @@ struct device { bool offline_disabled:1; bool offline:1; + bool dma_coherent:1; }; static inline struct device *kobj_to_dev(struct kobject *kobj) diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index d5d388160f42..9c9ba5a5428e 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -78,6 +78,11 @@ static inline int is_device_dma_capable(struct device *dev) return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE; } +static inline int is_device_dma_coherent(struct device *dev) +{ + return dev->dma_coherent; +} + #ifdef CONFIG_HAS_DMA #include <asm/dma-mapping.h> #else > However given the timing constraints I hope you would be OK with the > suboptimal solution for now and create a common is_dma_coherent function > in 3.19? If you want to push something for 3.18, you could have a temporary solution but I would prefer a bool or something in the dev_archdata structure. Another untested patch: diff --git a/arch/arm64/include/asm/device.h b/arch/arm64/include/asm/device.h index cf98b362094b..243ef256b8c9 100644 --- a/arch/arm64/include/asm/device.h +++ b/arch/arm64/include/asm/device.h @@ -21,6 +21,7 @@ struct dev_archdata { #ifdef CONFIG_IOMMU_API void *iommu; /* private IOMMU data */ #endif + bool dma_coherent; }; struct pdev_archdata { diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index adeae3f6f0fc..b6bc4c268878 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -54,11 +54,17 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops) static inline int set_arch_dma_coherent_ops(struct device *dev) { + dev->dev_archdata.dma_coherent = true; set_dma_ops(dev, &coherent_swiotlb_dma_ops); return 0; } #define set_arch_dma_coherent_ops set_arch_dma_coherent_ops +static inline int is_device_dma_coherent(struct device *dev) +{ + return dev->dev_archdata.dma_coherent; +} + #include <asm-generic/dma-mapping-common.h> static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)