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Commit cea9d03c authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: add an arch_dma_supported hook 



To implement the x86 forbid_dac and iommu_sac_force we want an arch hook
so that it can apply the global options across all dma_map_ops
implementations.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 57bf5a89

arch/x86/include/asm/dma-mapping.h

+3 −0
Original line number Diff line number Diff line
@@ -30,6 +30,9 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) 
	return dma_ops;

}



int arch_dma_supported(struct device *dev, u64 mask);

#define arch_dma_supported arch_dma_supported



bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);

#define arch_dma_alloc_attrs arch_dma_alloc_attrs

arch/x86/kernel/pci-dma.c

+12 −7
Original line number Diff line number Diff line
@@ -215,7 +215,7 @@ static __init int iommu_setup(char *p) 
}

early_param("iommu", iommu_setup);



int x86_dma_supported(struct device *dev, u64 mask)

int arch_dma_supported(struct device *dev, u64 mask)

{

#ifdef CONFIG_PCI

	if (mask > 0xffffffff && forbid_dac > 0) {
@@ -224,12 +224,6 @@ int x86_dma_supported(struct device *dev, u64 mask) 
	}

#endif



	/* Copied from i386. Doesn't make much sense, because it will

	   only work for pci_alloc_coherent.

	   The caller just has to use GFP_DMA in this case. */

	if (mask < DMA_BIT_MASK(24))

		return 0;



	/* Tell the device to use SAC when IOMMU force is on.  This

	   allows the driver to use cheaper accesses in some cases.
@@ -249,6 +243,17 @@ int x86_dma_supported(struct device *dev, u64 mask) 


	return 1;

}

EXPORT_SYMBOL(arch_dma_supported);



int x86_dma_supported(struct device *dev, u64 mask)

{

	/* Copied from i386. Doesn't make much sense, because it will

	   only work for pci_alloc_coherent.

	   The caller just has to use GFP_DMA in this case. */

	if (mask < DMA_BIT_MASK(24))

		return 0;

	return 1;

}



static int __init pci_iommu_init(void)

{

include/linux/dma-mapping.h

+11 −0
Original line number Diff line number Diff line
@@ -576,6 +576,14 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) 
	return 0;

}



/*

 * This is a hack for the legacy x86 forbid_dac and iommu_sac_force. Please

 * don't use this is new code.

 */

#ifndef arch_dma_supported

#define arch_dma_supported(dev, mask)	(1)

#endif



static inline void dma_check_mask(struct device *dev, u64 mask)

{

	if (sme_active() && (mask < (((u64)sme_get_me_mask() << 1) - 1)))
@@ -588,6 +596,9 @@ static inline int dma_supported(struct device *dev, u64 mask) 


	if (!ops)

		return 0;

	if (!arch_dma_supported(dev, mask))

		return 0;



	if (!ops->dma_supported)

		return 1;

	return ops->dma_supported(dev, mask);