On Thursday, May 07, 2015 07:37:13 PM Suravee Suthikulpanit wrote: > From http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf, > section 6.2.17 _CCA states that ARM platforms require ACPI _CCA > object to be specified for DMA-cabpable devices. This patch introduces > ACPI_MUST_HAVE_CCA in arm64 Kconfig to specify such requirement. > > In case _CCA is missing, arm64 would assign dummy_dma_ops > to disable DMA capability of the device. > > Signed-off-by: Mark Salter <msalter@xxxxxxxxxx> > Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> This won't go in without any ACKs from the ARM64 maintainers. > --- > arch/arm64/Kconfig | 2 + > arch/arm64/include/asm/dma-mapping.h | 18 ++++++- > arch/arm64/mm/dma-mapping.c | 92 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 110 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 4269dba..c7227e8 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1,5 +1,6 @@ > config ARM64 > def_bool y > + select ACPI_CCA_REQUIRED if ACPI > select ACPI_GENERIC_GSI if ACPI > select ACPI_REDUCED_HARDWARE_ONLY if ACPI > select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE > @@ -19,6 +20,7 @@ config ARM64 > select ARM_GIC_V2M if PCI_MSI > select ARM_GIC_V3 > select ARM_GIC_V3_ITS if PCI_MSI > + select ARM64_SUPPORT_ACPI_CCA_ZERO if ACPI > select BUILDTIME_EXTABLE_SORT > select CLONE_BACKWARDS > select COMMON_CLK > diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h > index 9437e3d..f0d6d0b 100644 > --- a/arch/arm64/include/asm/dma-mapping.h > +++ b/arch/arm64/include/asm/dma-mapping.h > @@ -18,6 +18,7 @@ > > #ifdef __KERNEL__ > > +#include <linux/acpi.h> > #include <linux/types.h> > #include <linux/vmalloc.h> > > @@ -28,13 +29,23 @@ > > #define DMA_ERROR_CODE (~(dma_addr_t)0) > extern struct dma_map_ops *dma_ops; > +extern struct dma_map_ops dummy_dma_ops; > > static inline struct dma_map_ops *__generic_dma_ops(struct device *dev) > { > - if (unlikely(!dev) || !dev->archdata.dma_ops) > + if (unlikely(!dev)) > return dma_ops; > - else > + else if (dev->archdata.dma_ops) > return dev->archdata.dma_ops; > + else if (acpi_disabled) > + return dma_ops; > + > + /* > + * When ACPI is enabled, if arch_set_dma_ops is not called, > + * we will disable device DMA capability by setting it > + * to dummy_dma_ops. > + */ > + return &dummy_dma_ops; > } > > static inline struct dma_map_ops *get_dma_ops(struct device *dev) > @@ -48,6 +59,9 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev) > static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, > struct iommu_ops *iommu, bool coherent) > { > + if (!acpi_disabled && !dev->archdata.dma_ops) > + dev->archdata.dma_ops = dma_ops; > + > dev->archdata.dma_coherent = coherent; > } > #define arch_setup_dma_ops arch_setup_dma_ops > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index ef7d112..6e6d6ad 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -415,6 +415,98 @@ out: > return -ENOMEM; > } > > +/******************************************** > + * The following APIs are for dummy DMA ops * > + ********************************************/ > + > +static void *__dummy_alloc(struct device *dev, size_t size, > + dma_addr_t *dma_handle, gfp_t flags, > + struct dma_attrs *attrs) > +{ > + return NULL; > +} > + > +static void __dummy_free(struct device *dev, size_t size, > + void *vaddr, dma_addr_t dma_handle, > + struct dma_attrs *attrs) > +{ > +} > + > +static int __dummy_mmap(struct device *dev, > + struct vm_area_struct *vma, > + void *cpu_addr, dma_addr_t dma_addr, size_t size, > + struct dma_attrs *attrs) > +{ > + return -ENXIO; > +} > + > +static dma_addr_t __dummy_map_page(struct device *dev, struct page *page, > + unsigned long offset, size_t size, > + enum dma_data_direction dir, > + struct dma_attrs *attrs) > +{ > + return DMA_ERROR_CODE; > +} > + > +static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr, > + size_t size, enum dma_data_direction dir, > + struct dma_attrs *attrs) > +{ > +} > + > +static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl, > + int nelems, enum dma_data_direction dir, > + struct dma_attrs *attrs) > +{ > + return 0; > +} > + > +static void __dummy_unmap_sg(struct device *dev, > + struct scatterlist *sgl, int nelems, > + enum dma_data_direction dir, > + struct dma_attrs *attrs) > +{ > +} > + > +static void __dummy_sync_single(struct device *dev, > + dma_addr_t dev_addr, size_t size, > + enum dma_data_direction dir) > +{ > +} > + > +static void __dummy_sync_sg(struct device *dev, > + struct scatterlist *sgl, int nelems, > + enum dma_data_direction dir) > +{ > +} > + > +static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr) > +{ > + return 1; > +} > + > +static int __dummy_dma_supported(struct device *hwdev, u64 mask) > +{ > + return 0; > +} > + > +struct dma_map_ops dummy_dma_ops = { > + .alloc = __dummy_alloc, > + .free = __dummy_free, > + .mmap = __dummy_mmap, > + .map_page = __dummy_map_page, > + .unmap_page = __dummy_unmap_page, > + .map_sg = __dummy_map_sg, > + .unmap_sg = __dummy_unmap_sg, > + .sync_single_for_cpu = __dummy_sync_single, > + .sync_single_for_device = __dummy_sync_single, > + .sync_sg_for_cpu = __dummy_sync_sg, > + .sync_sg_for_device = __dummy_sync_sg, > + .mapping_error = __dummy_mapping_error, > + .dma_supported = __dummy_dma_supported, > +}; > +EXPORT_SYMBOL(dummy_dma_ops); > + > static int __init arm64_dma_init(void) > { > int ret; > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
