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 if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
26 #ifdef __arch_page_to_dma
27 #error Please update to __arch_pfn_to_dma
31 * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
32 * functions used internally by the DMA-mapping API to provide DMA
33 * addresses. They must not be used by drivers.
35 #ifndef __arch_pfn_to_dma
36 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
39 pfn -= dev->dma_pfn_offset;
40 return (dma_addr_t)__pfn_to_bus(pfn);
43 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
45 unsigned long pfn = __bus_to_pfn(addr);
48 pfn += dev->dma_pfn_offset;
53 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
56 unsigned long pfn = dma_to_pfn(dev, addr);
58 return phys_to_virt(__pfn_to_phys(pfn));
61 return (void *)__bus_to_virt((unsigned long)addr);
64 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
67 return pfn_to_dma(dev, virt_to_pfn(addr));
69 return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
73 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
75 return __arch_pfn_to_dma(dev, pfn);
78 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
80 return __arch_dma_to_pfn(dev, addr);
83 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
85 return __arch_dma_to_virt(dev, addr);
88 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
90 return __arch_virt_to_dma(dev, addr);
94 /* do not use this function in a driver */
95 static inline bool is_device_dma_coherent(struct device *dev)
97 return dev->archdata.dma_coherent;
101 * arm_dma_alloc - allocate consistent memory for DMA
102 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
103 * @size: required memory size
104 * @handle: bus-specific DMA address
105 * @attrs: optinal attributes that specific mapping properties
107 * Allocate some memory for a device for performing DMA. This function
108 * allocates pages, and will return the CPU-viewed address, and sets @handle
109 * to be the device-viewed address.
111 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
112 gfp_t gfp, unsigned long attrs);
115 * arm_dma_free - free memory allocated by arm_dma_alloc
116 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
117 * @size: size of memory originally requested in dma_alloc_coherent
118 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
119 * @handle: device-view address returned from dma_alloc_coherent
120 * @attrs: optinal attributes that specific mapping properties
122 * Free (and unmap) a DMA buffer previously allocated by
125 * References to memory and mappings associated with cpu_addr/handle
126 * during and after this call executing are illegal.
128 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
129 dma_addr_t handle, unsigned long attrs);
132 * arm_dma_mmap - map a coherent DMA allocation into user space
133 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
134 * @vma: vm_area_struct describing requested user mapping
135 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
136 * @handle: device-view address returned from dma_alloc_coherent
137 * @size: size of memory originally requested in dma_alloc_coherent
138 * @attrs: optinal attributes that specific mapping properties
140 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
141 * into user space. The coherent DMA buffer must not be freed by the
142 * driver until the user space mapping has been released.
144 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
145 void *cpu_addr, dma_addr_t dma_addr, size_t size,
146 unsigned long attrs);
149 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
150 * and utilize bounce buffers as needed to work around limited DMA windows.
152 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
153 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
154 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
156 * The following are helper functions used by the dmabounce subystem
161 * dmabounce_register_dev
163 * @dev: valid struct device pointer
164 * @small_buf_size: size of buffers to use with small buffer pool
165 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
166 * @needs_bounce_fn: called to determine whether buffer needs bouncing
168 * This function should be called by low-level platform code to register
169 * a device as requireing DMA buffer bouncing. The function will allocate
170 * appropriate DMA pools for the device.
172 extern int dmabounce_register_dev(struct device *, unsigned long,
173 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
176 * dmabounce_unregister_dev
178 * @dev: valid struct device pointer
180 * This function should be called by low-level platform code when device
181 * that was previously registered with dmabounce_register_dev is removed
185 extern void dmabounce_unregister_dev(struct device *);
190 * The scatter list versions of the above methods.
192 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
193 enum dma_data_direction, unsigned long attrs);
194 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
195 enum dma_data_direction, unsigned long attrs);
196 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
197 enum dma_data_direction);
198 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
199 enum dma_data_direction);
200 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
201 void *cpu_addr, dma_addr_t dma_addr, size_t size,
202 unsigned long attrs);
204 #endif /* __KERNEL__ */