1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef ASMARM_DMA_MAPPING_H
3 #define ASMARM_DMA_MAPPING_H
4
5 #ifdef __KERNEL__
6
7 #include <linux/mm_types.h>
8 #include <linux/scatterlist.h>
9 #include <linux/dma-debug.h>
10
11 #include <asm/memory.h>
12
13 #include <xen/xen.h>
14 #include <asm/xen/hypervisor.h>
15
16 extern const struct dma_map_ops arm_dma_ops;
17 extern const struct dma_map_ops arm_coherent_dma_ops;
18
get_arch_dma_ops(struct bus_type * bus)19 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
20 {
21 return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops;
22 }
23
24 #ifdef __arch_page_to_dma
25 #error Please update to __arch_pfn_to_dma
26 #endif
27
28 /*
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.
32 */
33 #ifndef __arch_pfn_to_dma
pfn_to_dma(struct device * dev,unsigned long pfn)34 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
35 {
36 if (dev)
37 pfn -= dev->dma_pfn_offset;
38 return (dma_addr_t)__pfn_to_bus(pfn);
39 }
40
dma_to_pfn(struct device * dev,dma_addr_t addr)41 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
42 {
43 unsigned long pfn = __bus_to_pfn(addr);
44
45 if (dev)
46 pfn += dev->dma_pfn_offset;
47
48 return pfn;
49 }
50
dma_to_virt(struct device * dev,dma_addr_t addr)51 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
52 {
53 if (dev) {
54 unsigned long pfn = dma_to_pfn(dev, addr);
55
56 return phys_to_virt(__pfn_to_phys(pfn));
57 }
58
59 return (void *)__bus_to_virt((unsigned long)addr);
60 }
61
virt_to_dma(struct device * dev,void * addr)62 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
63 {
64 if (dev)
65 return pfn_to_dma(dev, virt_to_pfn(addr));
66
67 return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
68 }
69
70 #else
pfn_to_dma(struct device * dev,unsigned long pfn)71 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
72 {
73 return __arch_pfn_to_dma(dev, pfn);
74 }
75
dma_to_pfn(struct device * dev,dma_addr_t addr)76 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
77 {
78 return __arch_dma_to_pfn(dev, addr);
79 }
80
dma_to_virt(struct device * dev,dma_addr_t addr)81 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
82 {
83 return __arch_dma_to_virt(dev, addr);
84 }
85
virt_to_dma(struct device * dev,void * addr)86 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
87 {
88 return __arch_virt_to_dma(dev, addr);
89 }
90 #endif
91
92 /* The ARM override for dma_max_pfn() */
dma_max_pfn(struct device * dev)93 static inline unsigned long dma_max_pfn(struct device *dev)
94 {
95 return dma_to_pfn(dev, *dev->dma_mask);
96 }
97 #define dma_max_pfn(dev) dma_max_pfn(dev)
98
99 #define arch_setup_dma_ops arch_setup_dma_ops
100 extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
101 const struct iommu_ops *iommu, bool coherent);
102
103 #define arch_teardown_dma_ops arch_teardown_dma_ops
104 extern void arch_teardown_dma_ops(struct device *dev);
105
106 /* do not use this function in a driver */
is_device_dma_coherent(struct device * dev)107 static inline bool is_device_dma_coherent(struct device *dev)
108 {
109 return dev->archdata.dma_coherent;
110 }
111
112 /**
113 * arm_dma_alloc - allocate consistent memory for DMA
114 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
115 * @size: required memory size
116 * @handle: bus-specific DMA address
117 * @attrs: optinal attributes that specific mapping properties
118 *
119 * Allocate some memory for a device for performing DMA. This function
120 * allocates pages, and will return the CPU-viewed address, and sets @handle
121 * to be the device-viewed address.
122 */
123 extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
124 gfp_t gfp, unsigned long attrs);
125
126 /**
127 * arm_dma_free - free memory allocated by arm_dma_alloc
128 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
129 * @size: size of memory originally requested in dma_alloc_coherent
130 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
131 * @handle: device-view address returned from dma_alloc_coherent
132 * @attrs: optinal attributes that specific mapping properties
133 *
134 * Free (and unmap) a DMA buffer previously allocated by
135 * arm_dma_alloc().
136 *
137 * References to memory and mappings associated with cpu_addr/handle
138 * during and after this call executing are illegal.
139 */
140 extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
141 dma_addr_t handle, unsigned long attrs);
142
143 /**
144 * arm_dma_mmap - map a coherent DMA allocation into user space
145 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
146 * @vma: vm_area_struct describing requested user mapping
147 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
148 * @handle: device-view address returned from dma_alloc_coherent
149 * @size: size of memory originally requested in dma_alloc_coherent
150 * @attrs: optinal attributes that specific mapping properties
151 *
152 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
153 * into user space. The coherent DMA buffer must not be freed by the
154 * driver until the user space mapping has been released.
155 */
156 extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
157 void *cpu_addr, dma_addr_t dma_addr, size_t size,
158 unsigned long attrs);
159
160 /*
161 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
162 * and utilize bounce buffers as needed to work around limited DMA windows.
163 *
164 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
165 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
166 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
167 *
168 * The following are helper functions used by the dmabounce subystem
169 *
170 */
171
172 /**
173 * dmabounce_register_dev
174 *
175 * @dev: valid struct device pointer
176 * @small_buf_size: size of buffers to use with small buffer pool
177 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
178 * @needs_bounce_fn: called to determine whether buffer needs bouncing
179 *
180 * This function should be called by low-level platform code to register
181 * a device as requireing DMA buffer bouncing. The function will allocate
182 * appropriate DMA pools for the device.
183 */
184 extern int dmabounce_register_dev(struct device *, unsigned long,
185 unsigned long, int (*)(struct device *, dma_addr_t, size_t));
186
187 /**
188 * dmabounce_unregister_dev
189 *
190 * @dev: valid struct device pointer
191 *
192 * This function should be called by low-level platform code when device
193 * that was previously registered with dmabounce_register_dev is removed
194 * from the system.
195 *
196 */
197 extern void dmabounce_unregister_dev(struct device *);
198
199
200
201 /*
202 * The scatter list versions of the above methods.
203 */
204 extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
205 enum dma_data_direction, unsigned long attrs);
206 extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
207 enum dma_data_direction, unsigned long attrs);
208 extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
209 enum dma_data_direction);
210 extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
211 enum dma_data_direction);
212 extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
213 void *cpu_addr, dma_addr_t dma_addr, size_t size,
214 unsigned long attrs);
215
216 #endif /* __KERNEL__ */
217 #endif
218