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 /* The ARM override for dma_max_pfn() */
93 static inline unsigned long dma_max_pfn(struct device *dev)
95 return dma_to_pfn(dev, *dev->dma_mask);
97 #define dma_max_pfn(dev) dma_max_pfn(dev)
100 #define arch_teardown_dma_ops arch_teardown_dma_ops
101 extern void arch_teardown_dma_ops(struct device *dev);
104 /* do not use this function in a driver */
105 static inline bool is_device_dma_coherent(struct device *dev)
107 return dev->archdata.dma_coherent;
111 * arm_dma_alloc - allocate consistent memory for DMA
112 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
113 * @size: required memory size
114 * @handle: bus-specific DMA address
115 * @attrs: optinal attributes that specific mapping properties
117 * Allocate some memory for a device for performing DMA. This function
118 * allocates pages, and will return the CPU-viewed address, and sets @handle
119 * to be the device-viewed address.
121 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
122 gfp_t gfp, unsigned long attrs);
125 * arm_dma_free - free memory allocated by arm_dma_alloc
126 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
127 * @size: size of memory originally requested in dma_alloc_coherent
128 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
129 * @handle: device-view address returned from dma_alloc_coherent
130 * @attrs: optinal attributes that specific mapping properties
132 * Free (and unmap) a DMA buffer previously allocated by
135 * References to memory and mappings associated with cpu_addr/handle
136 * during and after this call executing are illegal.
138 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
139 dma_addr_t handle, unsigned long attrs);
142 * arm_dma_mmap - map a coherent DMA allocation into user space
143 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
144 * @vma: vm_area_struct describing requested user mapping
145 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
146 * @handle: device-view address returned from dma_alloc_coherent
147 * @size: size of memory originally requested in dma_alloc_coherent
148 * @attrs: optinal attributes that specific mapping properties
150 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
151 * into user space. The coherent DMA buffer must not be freed by the
152 * driver until the user space mapping has been released.
154 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
155 void *cpu_addr, dma_addr_t dma_addr, size_t size,
156 unsigned long attrs);
159 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
160 * and utilize bounce buffers as needed to work around limited DMA windows.
162 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
163 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
164 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
166 * The following are helper functions used by the dmabounce subystem
171 * dmabounce_register_dev
173 * @dev: valid struct device pointer
174 * @small_buf_size: size of buffers to use with small buffer pool
175 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
176 * @needs_bounce_fn: called to determine whether buffer needs bouncing
178 * This function should be called by low-level platform code to register
179 * a device as requireing DMA buffer bouncing. The function will allocate
180 * appropriate DMA pools for the device.
182 extern int dmabounce_register_dev(struct device *, unsigned long,
183 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
186 * dmabounce_unregister_dev
188 * @dev: valid struct device pointer
190 * This function should be called by low-level platform code when device
191 * that was previously registered with dmabounce_register_dev is removed
195 extern void dmabounce_unregister_dev(struct device *);
200 * The scatter list versions of the above methods.
202 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
203 enum dma_data_direction, unsigned long attrs);
204 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
205 enum dma_data_direction, unsigned long attrs);
206 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
207 enum dma_data_direction);
208 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
209 enum dma_data_direction);
210 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
211 void *cpu_addr, dma_addr_t dma_addr, size_t size,
212 unsigned long attrs);
214 #endif /* __KERNEL__ */