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		002e67454f
		
	
	
	
	
		
			
			The trivial direct mapping implementation already does a virtual to physical translation which isn't strictly a noop, and will soon learn to do non-direct but linear physical to dma translations through the device offset and a few small tricks. Rename it to a better fitting name. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
		
			
				
	
	
		
			218 lines
		
	
	
		
			6.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			218 lines
		
	
	
		
			6.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef ASMARM_DMA_MAPPING_H
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| #define ASMARM_DMA_MAPPING_H
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| 
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| #ifdef __KERNEL__
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| 
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| #include <linux/mm_types.h>
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| #include <linux/scatterlist.h>
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| #include <linux/dma-debug.h>
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| 
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| #include <asm/memory.h>
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| 
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| #include <xen/xen.h>
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| #include <asm/xen/hypervisor.h>
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| 
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| extern const struct dma_map_ops arm_dma_ops;
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| extern const struct dma_map_ops arm_coherent_dma_ops;
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| 
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| static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
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| {
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| 	return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops;
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| }
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| 
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| #ifdef __arch_page_to_dma
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| #error Please update to __arch_pfn_to_dma
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| #endif
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| 
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| /*
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|  * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
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|  * functions used internally by the DMA-mapping API to provide DMA
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|  * addresses. They must not be used by drivers.
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|  */
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| #ifndef __arch_pfn_to_dma
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| static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
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| {
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| 	if (dev)
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| 		pfn -= dev->dma_pfn_offset;
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| 	return (dma_addr_t)__pfn_to_bus(pfn);
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| }
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| 
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| static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
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| {
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| 	unsigned long pfn = __bus_to_pfn(addr);
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| 
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| 	if (dev)
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| 		pfn += dev->dma_pfn_offset;
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| 
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| 	return pfn;
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| }
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| 
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| static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
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| {
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| 	if (dev) {
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| 		unsigned long pfn = dma_to_pfn(dev, addr);
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| 
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| 		return phys_to_virt(__pfn_to_phys(pfn));
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| 	}
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| 
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| 	return (void *)__bus_to_virt((unsigned long)addr);
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| }
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| 
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| static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
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| {
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| 	if (dev)
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| 		return pfn_to_dma(dev, virt_to_pfn(addr));
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| 
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| 	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
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| }
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| 
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| #else
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| static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
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| {
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| 	return __arch_pfn_to_dma(dev, pfn);
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| }
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| 
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| static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
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| {
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| 	return __arch_dma_to_pfn(dev, addr);
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| }
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| 
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| static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
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| {
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| 	return __arch_dma_to_virt(dev, addr);
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| }
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| 
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| static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
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| {
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| 	return __arch_virt_to_dma(dev, addr);
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| }
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| #endif
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| 
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| /* The ARM override for dma_max_pfn() */
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| static inline unsigned long dma_max_pfn(struct device *dev)
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| {
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| 	return dma_to_pfn(dev, *dev->dma_mask);
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| }
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| #define dma_max_pfn(dev) dma_max_pfn(dev)
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| 
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| #define arch_setup_dma_ops arch_setup_dma_ops
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| extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
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| 			       const struct iommu_ops *iommu, bool coherent);
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| 
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| #define arch_teardown_dma_ops arch_teardown_dma_ops
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| extern void arch_teardown_dma_ops(struct device *dev);
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| 
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| /* do not use this function in a driver */
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| static inline bool is_device_dma_coherent(struct device *dev)
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| {
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| 	return dev->archdata.dma_coherent;
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| }
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| 
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| /**
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|  * arm_dma_alloc - allocate consistent memory for DMA
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|  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
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|  * @size: required memory size
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|  * @handle: bus-specific DMA address
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|  * @attrs: optinal attributes that specific mapping properties
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|  *
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|  * Allocate some memory for a device for performing DMA.  This function
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|  * allocates pages, and will return the CPU-viewed address, and sets @handle
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|  * to be the device-viewed address.
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|  */
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| extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
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| 			   gfp_t gfp, unsigned long attrs);
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| 
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| /**
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|  * arm_dma_free - free memory allocated by arm_dma_alloc
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|  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
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|  * @size: size of memory originally requested in dma_alloc_coherent
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|  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
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|  * @handle: device-view address returned from dma_alloc_coherent
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|  * @attrs: optinal attributes that specific mapping properties
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|  *
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|  * Free (and unmap) a DMA buffer previously allocated by
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|  * arm_dma_alloc().
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|  *
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|  * References to memory and mappings associated with cpu_addr/handle
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|  * during and after this call executing are illegal.
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|  */
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| extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
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| 			 dma_addr_t handle, unsigned long attrs);
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| 
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| /**
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|  * arm_dma_mmap - map a coherent DMA allocation into user space
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|  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
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|  * @vma: vm_area_struct describing requested user mapping
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|  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
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|  * @handle: device-view address returned from dma_alloc_coherent
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|  * @size: size of memory originally requested in dma_alloc_coherent
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|  * @attrs: optinal attributes that specific mapping properties
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|  *
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|  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
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|  * into user space.  The coherent DMA buffer must not be freed by the
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|  * driver until the user space mapping has been released.
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|  */
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| extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
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| 			void *cpu_addr, dma_addr_t dma_addr, size_t size,
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| 			unsigned long attrs);
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| 
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| /*
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|  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
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|  * and utilize bounce buffers as needed to work around limited DMA windows.
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|  *
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|  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
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|  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
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|  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
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|  *
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|  * The following are helper functions used by the dmabounce subystem
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|  *
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|  */
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| 
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| /**
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|  * dmabounce_register_dev
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|  *
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|  * @dev: valid struct device pointer
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|  * @small_buf_size: size of buffers to use with small buffer pool
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|  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
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|  * @needs_bounce_fn: called to determine whether buffer needs bouncing
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|  *
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|  * This function should be called by low-level platform code to register
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|  * a device as requireing DMA buffer bouncing. The function will allocate
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|  * appropriate DMA pools for the device.
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|  */
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| extern int dmabounce_register_dev(struct device *, unsigned long,
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| 		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
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| 
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| /**
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|  * dmabounce_unregister_dev
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|  *
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|  * @dev: valid struct device pointer
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|  *
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|  * This function should be called by low-level platform code when device
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|  * that was previously registered with dmabounce_register_dev is removed
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|  * from the system.
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|  *
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|  */
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| extern void dmabounce_unregister_dev(struct device *);
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| 
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| 
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| 
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| /*
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|  * The scatter list versions of the above methods.
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|  */
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| extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
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| 		enum dma_data_direction, unsigned long attrs);
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| extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
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| 		enum dma_data_direction, unsigned long attrs);
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| extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
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| 		enum dma_data_direction);
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| extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
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| 		enum dma_data_direction);
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| extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
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| 		void *cpu_addr, dma_addr_t dma_addr, size_t size,
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| 		unsigned long attrs);
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| 
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| #endif /* __KERNEL__ */
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| #endif
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