aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/include/asm/dma-mapping.h
blob: f41335ba63379ad77d5e75599be68b6f010ecc87 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
#ifndef ASMARM_DMA_MAPPING_H
#define ASMARM_DMA_MAPPING_H

#ifdef __KERNEL__

#include <linux/mm.h> /* need struct page */

#include <linux/scatterlist.h>

/*
 * DMA-consistent mapping functions.  These allocate/free a region of
 * uncached, unwrite-buffered mapped memory space for use with DMA
 * devices.  This is the "generic" version.  The PCI specific version
 * is in pci.h
 *
 * Note: Drivers should NOT use this function directly, as it will break
 * platforms with CONFIG_DMABOUNCE.
 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
 */
extern void dma_cache_maint(const void *kaddr, size_t size, int rw);

/*
 * Return whether the given device DMA address mask can be supported
 * properly.  For example, if your device can only drive the low 24-bits
 * during bus mastering, then you would pass 0x00ffffff as the mask
 * to this function.
 *
 * FIXME: This should really be a platform specific issue - we should
 * return false if GFP_DMA allocations may not satisfy the supplied 'mask'.
 */
static inline int dma_supported(struct device *dev, u64 mask)
{
	return dev->dma_mask && *dev->dma_mask != 0;
}

static inline int dma_set_mask(struct device *dev, u64 dma_mask)
{
	if (!dev->dma_mask || !dma_supported(dev, dma_mask))
		return -EIO;

	*dev->dma_mask = dma_mask;

	return 0;
}

static inline int dma_get_cache_alignment(void)
{
	return 32;
}

static inline int dma_is_consistent(struct device *dev, dma_addr_t handle)
{
	return !!arch_is_coherent();
}

/*
 * DMA errors are defined by all-bits-set in the DMA address.
 */
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
	return dma_addr == ~0;
}

/*
 * Dummy noncoherent implementation.  We don't provide a dma_cache_sync
 * function so drivers using this API are highlighted with build warnings.
 */
static inline void *
dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{
	return NULL;
}

static inline void
dma_free_noncoherent(struct device *dev, size_t size, void *cpu_addr,
		     dma_addr_t handle)
{
}

/**
 * dma_alloc_coherent - allocate consistent memory for DMA
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @size: required memory size
 * @handle: bus-specific DMA address
 *
 * Allocate some uncached, unbuffered memory for a device for
 * performing DMA.  This function allocates pages, and will
 * return the CPU-viewed address, and sets @handle to be the
 * device-viewed address.
 */
extern void *
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);

/**
 * dma_free_coherent - free memory allocated by dma_alloc_coherent
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @size: size of memory originally requested in dma_alloc_coherent
 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 * @handle: device-view address returned from dma_alloc_coherent
 *
 * Free (and unmap) a DMA buffer previously allocated by
 * dma_alloc_coherent().
 *
 * References to memory and mappings associated with cpu_addr/handle
 * during and after this call executing are illegal.
 */
extern void
dma_free_coherent(struct device *dev, size_t size, void *cpu_addr,
		  dma_addr_t handle);

/**
 * dma_mmap_coherent - map a coherent DMA allocation into user space
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @vma: vm_area_struct describing requested user mapping
 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 * @handle: device-view address returned from dma_alloc_coherent
 * @size: size of memory originally requested in dma_alloc_coherent
 *
 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 * into user space.  The coherent DMA buffer must not be freed by the
 * driver until the user space mapping has been released.
 */
int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
		      void *cpu_addr, dma_addr_t handle, size_t size);


/**
 * dma_alloc_writecombine - allocate writecombining memory for DMA
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @size: required memory size
 * @handle: bus-specific DMA address
 *
 * Allocate some uncached, buffered memory for a device for
 * performing DMA.  This function allocates pages, and will
 * return the CPU-viewed address, and sets @handle to be the
 * device-viewed address.
 */
extern void *
dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp);

#define dma_free_writecombine(dev,size,cpu_addr,handle) \
	dma_free_coherent(dev,size,cpu_addr,handle)

int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
			  void *cpu_addr, dma_addr_t handle, size_t size);


/**
 * dma_map_single - map a single buffer for streaming DMA
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @cpu_addr: CPU direct mapped address of buffer
 * @size: size of buffer to map
 * @dir: DMA transfer direction
 *
 * Ensure that any data held in the cache is appropriately discarded
 * or written back.
 *
 * The device owns this memory once this call has completed.  The CPU
 * can regain ownership by calling dma_unmap_single() or
 * dma_sync_single_for_cpu().
 */
#ifndef CONFIG_DMABOUNCE
static inline dma_addr_t
dma_map_single(struct device *dev, void *cpu_addr, size_t size,
	       enum dma_data_direction dir)
{
	if (!arch_is_coherent())
		dma_cache_maint(cpu_addr, size, dir);

	return virt_to_dma(dev, (unsigned long)cpu_addr);
}
#else
extern dma_addr_t dma_map_single(struct device *,void *, size_t, enum dma_data_direction);
#endif

/**
 * dma_map_page - map a portion of a page for streaming DMA
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @page: page that buffer resides in
 * @offset: offset into page for start of buffer
 * @size: size of buffer to map
 * @dir: DMA transfer direction
 *
 * Ensure that any data held in the cache is appropriately discarded
 * or written back.
 *
 * The device owns this memory once this call has completed.  The CPU
 * can regain ownership by calling dma_unmap_page() or
 * dma_sync_single_for_cpu().
 */
static inline dma_addr_t
dma_map_page(struct device *dev, struct page *page,
	     unsigned long offset, size_t size,
	     enum dma_data_direction dir)
{
	return dma_map_single(dev, page_address(page) + offset, size, (int)dir);
}

/**
 * dma_unmap_single - unmap a single buffer previously mapped
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @handle: DMA address of buffer
 * @size: size of buffer to map
 * @dir: DMA transfer direction
 *
 * Unmap a single streaming mode DMA translation.  The handle and size
 * must match what was provided in the previous dma_map_single() call.
 * All other usages are undefined.
 *
 * After this call, reads by the CPU to the buffer are guaranteed to see
 * whatever the device wrote there.
 */
#ifndef CONFIG_DMABOUNCE
static inline void
dma_unmap_single(struct device *dev, dma_addr_t handle, size_t size,
		 enum dma_data_direction dir)
{
	/* nothing to do */
}
#else
extern void dma_unmap_single(struct device *, dma_addr_t, size_t, enum dma_data_direction);
#endif

/**
 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @handle: DMA address of buffer
 * @size: size of buffer to map
 * @dir: DMA transfer direction
 *
 * Unmap a single streaming mode DMA translation.  The handle and size
 * must match what was provided in the previous dma_map_single() call.
 * All other usages are undefined.
 *
 * After this call, reads by the CPU to the buffer are guaranteed to see
 * whatever the device wrote there.
 */
static inline void
dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
	       enum dma_data_direction dir)
{
	dma_unmap_single(dev, handle, size, (int)dir);
}

/**
 * dma_map_sg - map a set of SG buffers for streaming mode DMA
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @sg: list of buffers
 * @nents: number of buffers to map
 * @dir: DMA transfer direction
 *
 * Map a set of buffers described by scatterlist in streaming
 * mode for DMA.  This is the scatter-gather version of the
 * above dma_map_single interface.  Here the scatter gather list
 * elements are each tagged with the appropriate dma address
 * and length.  They are obtained via sg_dma_{address,length}(SG).
 *
 * NOTE: An implementation may be able to use a smaller number of
 *       DMA address/length pairs than there are SG table elements.
 *       (for example via virtual mapping capabilities)
 *       The routine returns the number of addr/length pairs actually
 *       used, at most nents.
 *
 * Device ownership issues as mentioned above for dma_map_single are
 * the same here.
 */
#ifndef CONFIG_DMABOUNCE
static inline int
dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
	   enum dma_data_direction dir)
{
	int i;

	for (i = 0; i < nents; i++, sg++) {
		char *virt;

		sg->dma_address = page_to_dma(dev, sg_page(sg)) + sg->offset;
		virt = sg_virt(sg);

		if (!arch_is_coherent())
			dma_cache_maint(virt, sg->length, dir);
	}

	return nents;
}
#else
extern int dma_map_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
#endif

/**
 * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @sg: list of buffers
 * @nents: number of buffers to map
 * @dir: DMA transfer direction
 *
 * Unmap a set of streaming mode DMA translations.
 * Again, CPU read rules concerning calls here are the same as for
 * dma_unmap_single() above.
 */
#ifndef CONFIG_DMABOUNCE
static inline void
dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
	     enum dma_data_direction dir)
{

	/* nothing to do */
}
#else
extern void dma_unmap_sg(struct device *, struct scatterlist *, int, enum dma_data_direction);
#endif


/**
 * dma_sync_single_for_cpu
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @handle: DMA address of buffer
 * @size: size of buffer to map
 * @dir: DMA transfer direction
 *
 * Make physical memory consistent for a single streaming mode DMA
 * translation after a transfer.
 *
 * If you perform a dma_map_single() but wish to interrogate the
 * buffer using the cpu, yet do not wish to teardown the PCI dma
 * mapping, you must call this function before doing so.  At the
 * next point you give the PCI dma address back to the card, you
 * must first the perform a dma_sync_for_device, and then the
 * device again owns the buffer.
 */
#ifndef CONFIG_DMABOUNCE
static inline void
dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size,
			enum dma_data_direction dir)
{
	if (!arch_is_coherent())
		dma_cache_maint((void *)dma_to_virt(dev, handle), size, dir);
}

static inline void
dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size,
			   enum dma_data_direction dir)
{
	if (!arch_is_coherent())
		dma_cache_maint((void *)dma_to_virt(dev, handle), size, dir);
}
#else
extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction);
extern void dma_sync_single_for_device(struct device*, dma_addr_t, size_t, enum dma_data_direction);
#endif


/**
 * dma_sync_sg_for_cpu
 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 * @sg: list of buffers
 * @nents: number of buffers to map
 * @dir: DMA transfer direction
 *
 * Make physical memory consistent for a set of streaming
 * mode DMA translations after a transfer.
 *
 * The same as dma_sync_single_for_* but for a scatter-gather list,
 * same rules and usage.
 */
#ifndef CONFIG_DMABOUNCE
static inline void
dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
		    enum dma_data_direction dir)
{
	int i;

	for (i = 0; i < nents; i++, sg++) {
		char *virt = sg_virt(sg);
		if (!arch_is_coherent())
			dma_cache_maint(virt, sg->length, dir);
	}
}

static inline void
dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents,
		       enum dma_data_direction dir)
{
	int i;

	for (i = 0; i < nents; i++, sg++) {
		char *virt = sg_virt(sg);
		if (!arch_is_coherent())
			dma_cache_maint(virt, sg->length, dir);
	}
}
#else
extern void dma_sync_sg_for_cpu(struct device*, struct scatterlist*, int, enum dma_data_direction);
extern void dma_sync_sg_for_device(struct device*, struct scatterlist*, int, enum dma_data_direction);
#endif

#ifdef CONFIG_DMABOUNCE
/*
 * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 * and utilize bounce buffers as needed to work around limited DMA windows.
 *
 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 *
 * The following are helper functions used by the dmabounce subystem
 *
 */

/**
 * dmabounce_register_dev
 *
 * @dev: valid struct device pointer
 * @small_buf_size: size of buffers to use with small buffer pool
 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 *
 * This function should be called by low-level platform code to register
 * a device as requireing DMA buffer bouncing. The function will allocate
 * appropriate DMA pools for the device.
 *
 */
extern int dmabounce_register_dev(struct device *, unsigned long, unsigned long);

/**
 * dmabounce_unregister_dev
 *
 * @dev: valid struct device pointer
 *
 * This function should be called by low-level platform code when device
 * that was previously registered with dmabounce_register_dev is removed
 * from the system.
 *
 */
extern void dmabounce_unregister_dev(struct device *);

/**
 * dma_needs_bounce
 *
 * @dev: valid struct device pointer
 * @dma_handle: dma_handle of unbounced buffer
 * @size: size of region being mapped
 *
 * Platforms that utilize the dmabounce mechanism must implement
 * this function.
 *
 * The dmabounce routines call this function whenever a dma-mapping
 * is requested to determine whether a given buffer needs to be bounced
 * or not. The function must return 0 if the buffer is OK for
 * DMA access and 1 if the buffer needs to be bounced.
 *
 */
extern int dma_needs_bounce(struct device*, dma_addr_t, size_t);
#endif /* CONFIG_DMABOUNCE */

#endif /* __KERNEL__ */
#endif