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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ASMARM_DMA_MAPPING_H
#define ASMARM_DMA_MAPPING_H
#ifdef __KERNEL__
#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <xen/xen.h>
#include <asm/xen/hypervisor.h>
extern const struct dma_map_ops arm_dma_ops;
extern const struct dma_map_ops arm_coherent_dma_ops;
static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
return &arm_dma_ops;
return NULL;
}
/**
* arm_dma_alloc - allocate consistent memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
* @attrs: optinal attributes that specific mapping properties
*
* Allocate some memory for a device for performing DMA. This function
* allocates pages, and will return the CPU-viewed address, and sets @handle
* to be the device-viewed address.
*/
extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t gfp, unsigned long attrs);
/**
* arm_dma_free - free memory allocated by arm_dma_alloc
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: size of memory originally requested in dma_alloc_coherent
* @cpu_addr: CPU-view address returned from dma_alloc_coherent
* @handle: device-view address returned from dma_alloc_coherent
* @attrs: optinal attributes that specific mapping properties
*
* Free (and unmap) a DMA buffer previously allocated by
* arm_dma_alloc().
*
* References to memory and mappings associated with cpu_addr/handle
* during and after this call executing are illegal.
*/
extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, unsigned long attrs);
/**
* arm_dma_mmap - map a coherent DMA allocation into user space
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @vma: vm_area_struct describing requested user mapping
* @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
* @handle: device-view address returned from dma_alloc_coherent
* @size: size of memory originally requested in dma_alloc_coherent
* @attrs: optinal attributes that specific mapping properties
*
* Map a coherent DMA buffer previously allocated by dma_alloc_coherent
* into user space. The coherent DMA buffer must not be freed by the
* driver until the user space mapping has been released.
*/
extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs);
/*
* For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
* and utilize bounce buffers as needed to work around limited DMA windows.
*
* On the SA-1111, a bug limits DMA to only certain regions of RAM.
* On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
* On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
*
* The following are helper functions used by the dmabounce subystem
*
*/
/**
* dmabounce_register_dev
*
* @dev: valid struct device pointer
* @small_buf_size: size of buffers to use with small buffer pool
* @large_buf_size: size of buffers to use with large buffer pool (can be 0)
* @needs_bounce_fn: called to determine whether buffer needs bouncing
*
* This function should be called by low-level platform code to register
* a device as requireing DMA buffer bouncing. The function will allocate
* appropriate DMA pools for the device.
*/
extern int dmabounce_register_dev(struct device *, unsigned long,
unsigned long, int (*)(struct device *, dma_addr_t, size_t));
/**
* dmabounce_unregister_dev
*
* @dev: valid struct device pointer
*
* This function should be called by low-level platform code when device
* that was previously registered with dmabounce_register_dev is removed
* from the system.
*
*/
extern void dmabounce_unregister_dev(struct device *);
/*
* The scatter list versions of the above methods.
*/
extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
enum dma_data_direction, unsigned long attrs);
extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
enum dma_data_direction, unsigned long attrs);
extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
enum dma_data_direction);
extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs);
#endif /* __KERNEL__ */
#endif
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