1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef ASMARM_DMA_MAPPING_H
3 #define ASMARM_DMA_MAPPING_H
7 #include <linux/mm_types.h>
8 #include <linux/scatterlist.h>
9 #include <linux/dma-debug.h>
11 #include <asm/memory.h>
14 #include <asm/xen/hypervisor.h>
16 extern const struct dma_map_ops arm_dma_ops;
17 extern const struct dma_map_ops arm_coherent_dma_ops;
19 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
21 return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : NULL;
24 #ifdef __arch_page_to_dma
25 #error Please update to __arch_pfn_to_dma
29 * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
30 * functions used internally by the DMA-mapping API to provide DMA
31 * addresses. They must not be used by drivers.
33 #ifndef __arch_pfn_to_dma
34 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
37 pfn -= dev->dma_pfn_offset;
38 return (dma_addr_t)__pfn_to_bus(pfn);
41 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
43 unsigned long pfn = __bus_to_pfn(addr);
46 pfn += dev->dma_pfn_offset;
51 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
54 unsigned long pfn = dma_to_pfn(dev, addr);
56 return phys_to_virt(__pfn_to_phys(pfn));
59 return (void *)__bus_to_virt((unsigned long)addr);
62 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
65 return pfn_to_dma(dev, virt_to_pfn(addr));
67 return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
71 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
73 return __arch_pfn_to_dma(dev, pfn);
76 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
78 return __arch_dma_to_pfn(dev, addr);
81 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
83 return __arch_dma_to_virt(dev, addr);
86 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
88 return __arch_virt_to_dma(dev, addr);
92 /* do not use this function in a driver */
93 static inline bool is_device_dma_coherent(struct device *dev)
95 return dev->archdata.dma_coherent;
99 * arm_dma_alloc - allocate consistent memory for DMA
100 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
101 * @size: required memory size
102 * @handle: bus-specific DMA address
103 * @attrs: optinal attributes that specific mapping properties
105 * Allocate some memory for a device for performing DMA. This function
106 * allocates pages, and will return the CPU-viewed address, and sets @handle
107 * to be the device-viewed address.
109 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
110 gfp_t gfp, unsigned long attrs);
113 * arm_dma_free - free memory allocated by arm_dma_alloc
114 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
115 * @size: size of memory originally requested in dma_alloc_coherent
116 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
117 * @handle: device-view address returned from dma_alloc_coherent
118 * @attrs: optinal attributes that specific mapping properties
120 * Free (and unmap) a DMA buffer previously allocated by
123 * References to memory and mappings associated with cpu_addr/handle
124 * during and after this call executing are illegal.
126 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
127 dma_addr_t handle, unsigned long attrs);
130 * arm_dma_mmap - map a coherent DMA allocation into user space
131 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
132 * @vma: vm_area_struct describing requested user mapping
133 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
134 * @handle: device-view address returned from dma_alloc_coherent
135 * @size: size of memory originally requested in dma_alloc_coherent
136 * @attrs: optinal attributes that specific mapping properties
138 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
139 * into user space. The coherent DMA buffer must not be freed by the
140 * driver until the user space mapping has been released.
142 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
143 void *cpu_addr, dma_addr_t dma_addr, size_t size,
144 unsigned long attrs);
147 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
148 * and utilize bounce buffers as needed to work around limited DMA windows.
150 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
151 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
152 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
154 * The following are helper functions used by the dmabounce subystem
159 * dmabounce_register_dev
161 * @dev: valid struct device pointer
162 * @small_buf_size: size of buffers to use with small buffer pool
163 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
164 * @needs_bounce_fn: called to determine whether buffer needs bouncing
166 * This function should be called by low-level platform code to register
167 * a device as requireing DMA buffer bouncing. The function will allocate
168 * appropriate DMA pools for the device.
170 extern int dmabounce_register_dev(struct device *, unsigned long,
171 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
174 * dmabounce_unregister_dev
176 * @dev: valid struct device pointer
178 * This function should be called by low-level platform code when device
179 * that was previously registered with dmabounce_register_dev is removed
183 extern void dmabounce_unregister_dev(struct device *);
188 * The scatter list versions of the above methods.
190 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
191 enum dma_data_direction, unsigned long attrs);
192 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
193 enum dma_data_direction, unsigned long attrs);
194 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
195 enum dma_data_direction);
196 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
197 enum dma_data_direction);
198 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
199 void *cpu_addr, dma_addr_t dma_addr, size_t size,
200 unsigned long attrs);
202 #endif /* __KERNEL__ */