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Commit b6197b93 authored by Suthikulpanit, Suravee's avatar Suthikulpanit, Suravee Committed by Rafael J. Wysocki
Browse files

arm64 : Introduce support for ACPI _CCA object 



section 6.2.17 _CCA states that ARM platforms require ACPI _CCA
object to be specified for DMA-cabpable devices. Therefore, this patch
specifies ACPI_CCA_REQUIRED in arm64 Kconfig.

In addition, to handle the case when _CCA is missing, arm64 would assign
dummy_dma_ops to disable DMA capability of the device.

Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarMark Salter <msalter@redhat.com>
Signed-off-by: default avatarSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent d0562674

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line 
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

arch/arm64/include/asm/dma-mapping.h

+16 −2
Original line number Diff line number Diff line
@@ -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

arch/arm64/mm/dma-mapping.c

+92 −0
Original line number Diff line number Diff line
@@ -414,6 +414,98 @@ static int __init atomic_pool_init(void) 
	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;