129 строки
4.6 KiB
C
129 строки
4.6 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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#ifdef __KERNEL__
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#include <linux/mm_types.h>
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#include <linux/scatterlist.h>
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#include <xen/xen.h>
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#include <asm/xen/hypervisor.h>
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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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static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
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{
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if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
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return &arm_dma_ops;
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return NULL;
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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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* 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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* 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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* 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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* 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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* 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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* 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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#endif /* __KERNEL__ */
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#endif
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