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1 #ifndef ASMARM_DMA_MAPPING_H
2 #define ASMARM_DMA_MAPPING_H
3 
4 #ifdef __KERNEL__
5 
6 #include <linux/mm_types.h>
7 #include <linux/scatterlist.h>
8 #include <linux/dma-debug.h>
9 
10 #include <asm-generic/dma-coherent.h>
11 #include <asm/memory.h>
12 
13 #ifdef __arch_page_to_dma
14 #error Please update to __arch_pfn_to_dma
15 #endif
16 
17 /*
18  * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
19  * functions used internally by the DMA-mapping API to provide DMA
20  * addresses. They must not be used by drivers.
21  */
22 #ifndef __arch_pfn_to_dma
pfn_to_dma(struct device * dev,unsigned long pfn)23 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
24 {
25 	return (dma_addr_t)__pfn_to_bus(pfn);
26 }
27 
dma_to_pfn(struct device * dev,dma_addr_t addr)28 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
29 {
30 	return __bus_to_pfn(addr);
31 }
32 
dma_to_virt(struct device * dev,dma_addr_t addr)33 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
34 {
35 	return (void *)__bus_to_virt((unsigned long)addr);
36 }
37 
virt_to_dma(struct device * dev,void * addr)38 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
39 {
40 	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
41 }
42 #else
pfn_to_dma(struct device * dev,unsigned long pfn)43 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
44 {
45 	return __arch_pfn_to_dma(dev, pfn);
46 }
47 
dma_to_pfn(struct device * dev,dma_addr_t addr)48 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
49 {
50 	return __arch_dma_to_pfn(dev, addr);
51 }
52 
dma_to_virt(struct device * dev,dma_addr_t addr)53 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
54 {
55 	return __arch_dma_to_virt(dev, addr);
56 }
57 
virt_to_dma(struct device * dev,void * addr)58 static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
59 {
60 	return __arch_virt_to_dma(dev, addr);
61 }
62 #endif
63 
64 /*
65  * The DMA API is built upon the notion of "buffer ownership".  A buffer
66  * is either exclusively owned by the CPU (and therefore may be accessed
67  * by it) or exclusively owned by the DMA device.  These helper functions
68  * represent the transitions between these two ownership states.
69  *
70  * Note, however, that on later ARMs, this notion does not work due to
71  * speculative prefetches.  We model our approach on the assumption that
72  * the CPU does do speculative prefetches, which means we clean caches
73  * before transfers and delay cache invalidation until transfer completion.
74  *
75  * Private support functions: these are not part of the API and are
76  * liable to change.  Drivers must not use these.
77  */
__dma_single_cpu_to_dev(const void * kaddr,size_t size,enum dma_data_direction dir)78 static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
79 	enum dma_data_direction dir)
80 {
81 	extern void ___dma_single_cpu_to_dev(const void *, size_t,
82 		enum dma_data_direction);
83 
84 	if (!arch_is_coherent())
85 		___dma_single_cpu_to_dev(kaddr, size, dir);
86 }
87 
__dma_single_dev_to_cpu(const void * kaddr,size_t size,enum dma_data_direction dir)88 static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
89 	enum dma_data_direction dir)
90 {
91 	extern void ___dma_single_dev_to_cpu(const void *, size_t,
92 		enum dma_data_direction);
93 
94 	if (!arch_is_coherent())
95 		___dma_single_dev_to_cpu(kaddr, size, dir);
96 }
97 
__dma_page_cpu_to_dev(struct page * page,unsigned long off,size_t size,enum dma_data_direction dir)98 static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
99 	size_t size, enum dma_data_direction dir)
100 {
101 	extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
102 		size_t, enum dma_data_direction);
103 
104 	if (!arch_is_coherent())
105 		___dma_page_cpu_to_dev(page, off, size, dir);
106 }
107 
__dma_page_dev_to_cpu(struct page * page,unsigned long off,size_t size,enum dma_data_direction dir)108 static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
109 	size_t size, enum dma_data_direction dir)
110 {
111 	extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
112 		size_t, enum dma_data_direction);
113 
114 	if (!arch_is_coherent())
115 		___dma_page_dev_to_cpu(page, off, size, dir);
116 }
117 
118 extern int dma_supported(struct device *, u64);
119 extern int dma_set_mask(struct device *, u64);
120 
121 /*
122  * DMA errors are defined by all-bits-set in the DMA address.
123  */
dma_mapping_error(struct device * dev,dma_addr_t dma_addr)124 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
125 {
126 	return dma_addr == ~0;
127 }
128 
129 /*
130  * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
131  * function so drivers using this API are highlighted with build warnings.
132  */
dma_alloc_noncoherent(struct device * dev,size_t size,dma_addr_t * handle,gfp_t gfp)133 static inline void *dma_alloc_noncoherent(struct device *dev, size_t size,
134 		dma_addr_t *handle, gfp_t gfp)
135 {
136 	return NULL;
137 }
138 
dma_free_noncoherent(struct device * dev,size_t size,void * cpu_addr,dma_addr_t handle)139 static inline void dma_free_noncoherent(struct device *dev, size_t size,
140 		void *cpu_addr, dma_addr_t handle)
141 {
142 }
143 
144 /**
145  * dma_alloc_coherent - allocate consistent memory for DMA
146  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
147  * @size: required memory size
148  * @handle: bus-specific DMA address
149  *
150  * Allocate some uncached, unbuffered memory for a device for
151  * performing DMA.  This function allocates pages, and will
152  * return the CPU-viewed address, and sets @handle to be the
153  * device-viewed address.
154  */
155 extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
156 
157 /**
158  * dma_free_coherent - free memory allocated by dma_alloc_coherent
159  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
160  * @size: size of memory originally requested in dma_alloc_coherent
161  * @cpu_addr: CPU-view address returned from dma_alloc_coherent
162  * @handle: device-view address returned from dma_alloc_coherent
163  *
164  * Free (and unmap) a DMA buffer previously allocated by
165  * dma_alloc_coherent().
166  *
167  * References to memory and mappings associated with cpu_addr/handle
168  * during and after this call executing are illegal.
169  */
170 extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
171 
172 /**
173  * dma_mmap_coherent - map a coherent DMA allocation into user space
174  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
175  * @vma: vm_area_struct describing requested user mapping
176  * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
177  * @handle: device-view address returned from dma_alloc_coherent
178  * @size: size of memory originally requested in dma_alloc_coherent
179  *
180  * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
181  * into user space.  The coherent DMA buffer must not be freed by the
182  * driver until the user space mapping has been released.
183  */
184 int dma_mmap_coherent(struct device *, struct vm_area_struct *,
185 		void *, dma_addr_t, size_t);
186 
187 
188 /**
189  * dma_alloc_writecombine - allocate writecombining memory for DMA
190  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
191  * @size: required memory size
192  * @handle: bus-specific DMA address
193  *
194  * Allocate some uncached, buffered memory for a device for
195  * performing DMA.  This function allocates pages, and will
196  * return the CPU-viewed address, and sets @handle to be the
197  * device-viewed address.
198  */
199 extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
200 		gfp_t);
201 
202 #define dma_free_writecombine(dev,size,cpu_addr,handle) \
203 	dma_free_coherent(dev,size,cpu_addr,handle)
204 
205 int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
206 		void *, dma_addr_t, size_t);
207 
208 /*
209  * This can be called during boot to increase the size of the consistent
210  * DMA region above it's default value of 2MB. It must be called before the
211  * memory allocator is initialised, i.e. before any core_initcall.
212  */
213 extern void __init init_consistent_dma_size(unsigned long size);
214 
215 
216 #ifdef CONFIG_DMABOUNCE
217 /*
218  * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
219  * and utilize bounce buffers as needed to work around limited DMA windows.
220  *
221  * On the SA-1111, a bug limits DMA to only certain regions of RAM.
222  * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
223  * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
224  *
225  * The following are helper functions used by the dmabounce subystem
226  *
227  */
228 
229 /**
230  * dmabounce_register_dev
231  *
232  * @dev: valid struct device pointer
233  * @small_buf_size: size of buffers to use with small buffer pool
234  * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
235  * @needs_bounce_fn: called to determine whether buffer needs bouncing
236  *
237  * This function should be called by low-level platform code to register
238  * a device as requireing DMA buffer bouncing. The function will allocate
239  * appropriate DMA pools for the device.
240  */
241 extern int dmabounce_register_dev(struct device *, unsigned long,
242 		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
243 
244 /**
245  * dmabounce_unregister_dev
246  *
247  * @dev: valid struct device pointer
248  *
249  * This function should be called by low-level platform code when device
250  * that was previously registered with dmabounce_register_dev is removed
251  * from the system.
252  *
253  */
254 extern void dmabounce_unregister_dev(struct device *);
255 
256 /*
257  * The DMA API, implemented by dmabounce.c.  See below for descriptions.
258  */
259 extern dma_addr_t __dma_map_page(struct device *, struct page *,
260 		unsigned long, size_t, enum dma_data_direction);
261 extern void __dma_unmap_page(struct device *, dma_addr_t, size_t,
262 		enum dma_data_direction);
263 
264 /*
265  * Private functions
266  */
267 int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long,
268 		size_t, enum dma_data_direction);
269 int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long,
270 		size_t, enum dma_data_direction);
271 #else
dmabounce_sync_for_cpu(struct device * d,dma_addr_t addr,unsigned long offset,size_t size,enum dma_data_direction dir)272 static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr,
273 	unsigned long offset, size_t size, enum dma_data_direction dir)
274 {
275 	return 1;
276 }
277 
dmabounce_sync_for_device(struct device * d,dma_addr_t addr,unsigned long offset,size_t size,enum dma_data_direction dir)278 static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr,
279 	unsigned long offset, size_t size, enum dma_data_direction dir)
280 {
281 	return 1;
282 }
283 
284 
__dma_map_page(struct device * dev,struct page * page,unsigned long offset,size_t size,enum dma_data_direction dir)285 static inline dma_addr_t __dma_map_page(struct device *dev, struct page *page,
286 	     unsigned long offset, size_t size, enum dma_data_direction dir)
287 {
288 	__dma_page_cpu_to_dev(page, offset, size, dir);
289 	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
290 }
291 
__dma_unmap_page(struct device * dev,dma_addr_t handle,size_t size,enum dma_data_direction dir)292 static inline void __dma_unmap_page(struct device *dev, dma_addr_t handle,
293 		size_t size, enum dma_data_direction dir)
294 {
295 	__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
296 		handle & ~PAGE_MASK, size, dir);
297 }
298 #endif /* CONFIG_DMABOUNCE */
299 
300 /**
301  * dma_map_single - map a single buffer for streaming DMA
302  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
303  * @cpu_addr: CPU direct mapped address of buffer
304  * @size: size of buffer to map
305  * @dir: DMA transfer direction
306  *
307  * Ensure that any data held in the cache is appropriately discarded
308  * or written back.
309  *
310  * The device owns this memory once this call has completed.  The CPU
311  * can regain ownership by calling dma_unmap_single() or
312  * dma_sync_single_for_cpu().
313  */
dma_map_single(struct device * dev,void * cpu_addr,size_t size,enum dma_data_direction dir)314 static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr,
315 		size_t size, enum dma_data_direction dir)
316 {
317 	unsigned long offset;
318 	struct page *page;
319 	dma_addr_t addr;
320 
321 	BUG_ON(!virt_addr_valid(cpu_addr));
322 	BUG_ON(!virt_addr_valid(cpu_addr + size - 1));
323 	BUG_ON(!valid_dma_direction(dir));
324 
325 	page = virt_to_page(cpu_addr);
326 	offset = (unsigned long)cpu_addr & ~PAGE_MASK;
327 	addr = __dma_map_page(dev, page, offset, size, dir);
328 	debug_dma_map_page(dev, page, offset, size, dir, addr, true);
329 
330 	return addr;
331 }
332 
333 /**
334  * dma_map_page - map a portion of a page for streaming DMA
335  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
336  * @page: page that buffer resides in
337  * @offset: offset into page for start of buffer
338  * @size: size of buffer to map
339  * @dir: DMA transfer direction
340  *
341  * Ensure that any data held in the cache is appropriately discarded
342  * or written back.
343  *
344  * The device owns this memory once this call has completed.  The CPU
345  * can regain ownership by calling dma_unmap_page().
346  */
dma_map_page(struct device * dev,struct page * page,unsigned long offset,size_t size,enum dma_data_direction dir)347 static inline dma_addr_t dma_map_page(struct device *dev, struct page *page,
348 	     unsigned long offset, size_t size, enum dma_data_direction dir)
349 {
350 	dma_addr_t addr;
351 
352 	BUG_ON(!valid_dma_direction(dir));
353 
354 	addr = __dma_map_page(dev, page, offset, size, dir);
355 	debug_dma_map_page(dev, page, offset, size, dir, addr, false);
356 
357 	return addr;
358 }
359 
360 /**
361  * dma_unmap_single - unmap a single buffer previously mapped
362  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
363  * @handle: DMA address of buffer
364  * @size: size of buffer (same as passed to dma_map_single)
365  * @dir: DMA transfer direction (same as passed to dma_map_single)
366  *
367  * Unmap a single streaming mode DMA translation.  The handle and size
368  * must match what was provided in the previous dma_map_single() call.
369  * All other usages are undefined.
370  *
371  * After this call, reads by the CPU to the buffer are guaranteed to see
372  * whatever the device wrote there.
373  */
dma_unmap_single(struct device * dev,dma_addr_t handle,size_t size,enum dma_data_direction dir)374 static inline void dma_unmap_single(struct device *dev, dma_addr_t handle,
375 		size_t size, enum dma_data_direction dir)
376 {
377 	debug_dma_unmap_page(dev, handle, size, dir, true);
378 	__dma_unmap_page(dev, handle, size, dir);
379 }
380 
381 /**
382  * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
383  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
384  * @handle: DMA address of buffer
385  * @size: size of buffer (same as passed to dma_map_page)
386  * @dir: DMA transfer direction (same as passed to dma_map_page)
387  *
388  * Unmap a page streaming mode DMA translation.  The handle and size
389  * must match what was provided in the previous dma_map_page() call.
390  * All other usages are undefined.
391  *
392  * After this call, reads by the CPU to the buffer are guaranteed to see
393  * whatever the device wrote there.
394  */
dma_unmap_page(struct device * dev,dma_addr_t handle,size_t size,enum dma_data_direction dir)395 static inline void dma_unmap_page(struct device *dev, dma_addr_t handle,
396 		size_t size, enum dma_data_direction dir)
397 {
398 	debug_dma_unmap_page(dev, handle, size, dir, false);
399 	__dma_unmap_page(dev, handle, size, dir);
400 }
401 
402 /**
403  * dma_sync_single_range_for_cpu
404  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
405  * @handle: DMA address of buffer
406  * @offset: offset of region to start sync
407  * @size: size of region to sync
408  * @dir: DMA transfer direction (same as passed to dma_map_single)
409  *
410  * Make physical memory consistent for a single streaming mode DMA
411  * translation after a transfer.
412  *
413  * If you perform a dma_map_single() but wish to interrogate the
414  * buffer using the cpu, yet do not wish to teardown the PCI dma
415  * mapping, you must call this function before doing so.  At the
416  * next point you give the PCI dma address back to the card, you
417  * must first the perform a dma_sync_for_device, and then the
418  * device again owns the buffer.
419  */
dma_sync_single_range_for_cpu(struct device * dev,dma_addr_t handle,unsigned long offset,size_t size,enum dma_data_direction dir)420 static inline void dma_sync_single_range_for_cpu(struct device *dev,
421 		dma_addr_t handle, unsigned long offset, size_t size,
422 		enum dma_data_direction dir)
423 {
424 	BUG_ON(!valid_dma_direction(dir));
425 
426 	debug_dma_sync_single_for_cpu(dev, handle + offset, size, dir);
427 
428 	if (!dmabounce_sync_for_cpu(dev, handle, offset, size, dir))
429 		return;
430 
431 	__dma_single_dev_to_cpu(dma_to_virt(dev, handle) + offset, size, dir);
432 }
433 
dma_sync_single_range_for_device(struct device * dev,dma_addr_t handle,unsigned long offset,size_t size,enum dma_data_direction dir)434 static inline void dma_sync_single_range_for_device(struct device *dev,
435 		dma_addr_t handle, unsigned long offset, size_t size,
436 		enum dma_data_direction dir)
437 {
438 	BUG_ON(!valid_dma_direction(dir));
439 
440 	debug_dma_sync_single_for_device(dev, handle + offset, size, dir);
441 
442 	if (!dmabounce_sync_for_device(dev, handle, offset, size, dir))
443 		return;
444 
445 	__dma_single_cpu_to_dev(dma_to_virt(dev, handle) + offset, size, dir);
446 }
447 
dma_sync_single_for_cpu(struct device * dev,dma_addr_t handle,size_t size,enum dma_data_direction dir)448 static inline void dma_sync_single_for_cpu(struct device *dev,
449 		dma_addr_t handle, size_t size, enum dma_data_direction dir)
450 {
451 	dma_sync_single_range_for_cpu(dev, handle, 0, size, dir);
452 }
453 
dma_sync_single_for_device(struct device * dev,dma_addr_t handle,size_t size,enum dma_data_direction dir)454 static inline void dma_sync_single_for_device(struct device *dev,
455 		dma_addr_t handle, size_t size, enum dma_data_direction dir)
456 {
457 	dma_sync_single_range_for_device(dev, handle, 0, size, dir);
458 }
459 
460 /*
461  * The scatter list versions of the above methods.
462  */
463 extern int dma_map_sg(struct device *, struct scatterlist *, int,
464 		enum dma_data_direction);
465 extern void dma_unmap_sg(struct device *, struct scatterlist *, int,
466 		enum dma_data_direction);
467 extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
468 		enum dma_data_direction);
469 extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
470 		enum dma_data_direction);
471 
472 
473 #endif /* __KERNEL__ */
474 #endif
475