summaryrefslogtreecommitdiff
path: root/arch/mips/mm/dma-default.c
blob: 237532e899194a029ccc7278a8e744fefcbadff5 (plain)
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
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2000  Ani Joshi <ajoshi@unixbox.com>
 * Copyright (C) 2000, 2001, 06	 Ralf Baechle <ralf@linux-mips.org>
 * swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
 */

#include <linux/types.h>
#include <linux/dma-mapping.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/scatterlist.h>
#include <linux/string.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/dma-contiguous.h>

#include <asm/cache.h>
#include <asm/cpu-type.h>
#include <asm/io.h>

#include <dma-coherence.h>

#if defined(CONFIG_DMA_MAYBE_COHERENT) && !defined(CONFIG_DMA_PERDEV_COHERENT)
/* User defined DMA coherency from command line. */
enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
EXPORT_SYMBOL_GPL(coherentio);
int hw_coherentio = 0;	/* Actual hardware supported DMA coherency setting. */

static int __init setcoherentio(char *str)
{
	coherentio = IO_COHERENCE_ENABLED;
	pr_info("Hardware DMA cache coherency (command line)\n");
	return 0;
}
early_param("coherentio", setcoherentio);

static int __init setnocoherentio(char *str)
{
	coherentio = IO_COHERENCE_DISABLED;
	pr_info("Software DMA cache coherency (command line)\n");
	return 0;
}
early_param("nocoherentio", setnocoherentio);
#endif

static inline struct page *dma_addr_to_page(struct device *dev,
	dma_addr_t dma_addr)
{
	return pfn_to_page(
		plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
}

/*
 * The affected CPUs below in 'cpu_needs_post_dma_flush()' can
 * speculatively fill random cachelines with stale data at any time,
 * requiring an extra flush post-DMA.
 *
 * Warning on the terminology - Linux calls an uncached area coherent;
 * MIPS terminology calls memory areas with hardware maintained coherency
 * coherent.
 *
 * Note that the R14000 and R16000 should also be checked for in this
 * condition.  However this function is only called on non-I/O-coherent
 * systems and only the R10000 and R12000 are used in such systems, the
 * SGI IP28 Indigo² rsp. SGI IP32 aka O2.
 */
static inline bool cpu_needs_post_dma_flush(struct device *dev)
{
	if (plat_device_is_coherent(dev))
		return false;

	switch (boot_cpu_type()) {
	case CPU_R10000:
	case CPU_R12000:
	case CPU_BMIPS5000:
		return true;

	default:
		/*
		 * Presence of MAARs suggests that the CPU supports
		 * speculatively prefetching data, and therefore requires
		 * the post-DMA flush/invalidate.
		 */
		return cpu_has_maar;
	}
}

static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
{
	gfp_t dma_flag;

#ifdef CONFIG_ISA
	if (dev == NULL)
		dma_flag = __GFP_DMA;
	else
#endif
#if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
	     if (dev == NULL || dev->coherent_dma_mask < DMA_BIT_MASK(32))
			dma_flag = __GFP_DMA;
	else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
			dma_flag = __GFP_DMA32;
	else
#endif
#if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
	     if (dev == NULL || dev->coherent_dma_mask < DMA_BIT_MASK(64))
		dma_flag = __GFP_DMA32;
	else
#endif
#if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
	     if (dev == NULL ||
		 dev->coherent_dma_mask < DMA_BIT_MASK(sizeof(phys_addr_t) * 8))
		dma_flag = __GFP_DMA;
	else
#endif
		dma_flag = 0;

	/* Don't invoke OOM killer */
	gfp |= __GFP_NORETRY;

	return gfp | dma_flag;
}

static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
	dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
	void *ret;
	struct page *page = NULL;
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	gfp = massage_gfp_flags(dev, gfp);

	if (IS_ENABLED(CONFIG_DMA_CMA) && gfpflags_allow_blocking(gfp))
		page = dma_alloc_from_contiguous(dev, count, get_order(size),
						 gfp);
	if (!page)
		page = alloc_pages(gfp, get_order(size));

	if (!page)
		return NULL;

	ret = page_address(page);
	memset(ret, 0, size);
	*dma_handle = plat_map_dma_mem(dev, ret, size);
	if (!(attrs & DMA_ATTR_NON_CONSISTENT) &&
	    !plat_device_is_coherent(dev)) {
		dma_cache_wback_inv((unsigned long) ret, size);
		ret = UNCAC_ADDR(ret);
	}

	return ret;
}

static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
	dma_addr_t dma_handle, unsigned long attrs)
{
	unsigned long addr = (unsigned long) vaddr;
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
	struct page *page = NULL;

	plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);

	if (!(attrs & DMA_ATTR_NON_CONSISTENT) && !plat_device_is_coherent(dev))
		addr = CAC_ADDR(addr);

	page = virt_to_page((void *) addr);

	if (!dma_release_from_contiguous(dev, page, count))
		__free_pages(page, get_order(size));
}

static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
	void *cpu_addr, dma_addr_t dma_addr, size_t size,
	unsigned long attrs)
{
	unsigned long user_count = vma_pages(vma);
	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
	unsigned long addr = (unsigned long)cpu_addr;
	unsigned long off = vma->vm_pgoff;
	unsigned long pfn;
	int ret = -ENXIO;

	if (!plat_device_is_coherent(dev))
		addr = CAC_ADDR(addr);

	pfn = page_to_pfn(virt_to_page((void *)addr));

	if (attrs & DMA_ATTR_WRITE_COMBINE)
		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
	else
		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
		return ret;

	if (off < count && user_count <= (count - off)) {
		ret = remap_pfn_range(vma, vma->vm_start,
				      pfn + off,
				      user_count << PAGE_SHIFT,
				      vma->vm_page_prot);
	}

	return ret;
}

static inline void __dma_sync_virtual(void *addr, size_t size,
	enum dma_data_direction direction)
{
	switch (direction) {
	case DMA_TO_DEVICE:
		dma_cache_wback((unsigned long)addr, size);
		break;

	case DMA_FROM_DEVICE:
		dma_cache_inv((unsigned long)addr, size);
		break;

	case DMA_BIDIRECTIONAL:
		dma_cache_wback_inv((unsigned long)addr, size);
		break;

	default:
		BUG();
	}
}

/*
 * A single sg entry may refer to multiple physically contiguous
 * pages. But we still need to process highmem pages individually.
 * If highmem is not configured then the bulk of this loop gets
 * optimized out.
 */
static inline void __dma_sync(struct page *page,
	unsigned long offset, size_t size, enum dma_data_direction direction)
{
	size_t left = size;

	do {
		size_t len = left;

		if (PageHighMem(page)) {
			void *addr;

			if (offset + len > PAGE_SIZE) {
				if (offset >= PAGE_SIZE) {
					page += offset >> PAGE_SHIFT;
					offset &= ~PAGE_MASK;
				}
				len = PAGE_SIZE - offset;
			}

			addr = kmap_atomic(page);
			__dma_sync_virtual(addr + offset, len, direction);
			kunmap_atomic(addr);
		} else
			__dma_sync_virtual(page_address(page) + offset,
					   size, direction);
		offset = 0;
		page++;
		left -= len;
	} while (left);
}

static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr,
	size_t size, enum dma_data_direction direction, unsigned long attrs)
{
	if (cpu_needs_post_dma_flush(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
		__dma_sync(dma_addr_to_page(dev, dma_addr),
			   dma_addr & ~PAGE_MASK, size, direction);
	plat_post_dma_flush(dev);
	plat_unmap_dma_mem(dev, dma_addr, size, direction);
}

static int mips_dma_map_sg(struct device *dev, struct scatterlist *sglist,
	int nents, enum dma_data_direction direction, unsigned long attrs)
{
	int i;
	struct scatterlist *sg;

	for_each_sg(sglist, sg, nents, i) {
		if (!plat_device_is_coherent(dev) &&
		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
			__dma_sync(sg_page(sg), sg->offset, sg->length,
				   direction);
#ifdef CONFIG_NEED_SG_DMA_LENGTH
		sg->dma_length = sg->length;
#endif
		sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) +
				  sg->offset;
	}

	return nents;
}

static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
	unsigned long offset, size_t size, enum dma_data_direction direction,
	unsigned long attrs)
{
	if (!plat_device_is_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
		__dma_sync(page, offset, size, direction);

	return plat_map_dma_mem_page(dev, page) + offset;
}

static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
	int nhwentries, enum dma_data_direction direction,
	unsigned long attrs)
{
	int i;
	struct scatterlist *sg;

	for_each_sg(sglist, sg, nhwentries, i) {
		if (!plat_device_is_coherent(dev) &&
		    !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
		    direction != DMA_TO_DEVICE)
			__dma_sync(sg_page(sg), sg->offset, sg->length,
				   direction);
		plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
	}
}

static void mips_dma_sync_single_for_cpu(struct device *dev,
	dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
{
	if (cpu_needs_post_dma_flush(dev))
		__dma_sync(dma_addr_to_page(dev, dma_handle),
			   dma_handle & ~PAGE_MASK, size, direction);
	plat_post_dma_flush(dev);
}

static void mips_dma_sync_single_for_device(struct device *dev,
	dma_addr_t dma_handle, size_t size, enum dma_data_direction direction)
{
	if (!plat_device_is_coherent(dev))
		__dma_sync(dma_addr_to_page(dev, dma_handle),
			   dma_handle & ~PAGE_MASK, size, direction);
}

static void mips_dma_sync_sg_for_cpu(struct device *dev,
	struct scatterlist *sglist, int nelems,
	enum dma_data_direction direction)
{
	int i;
	struct scatterlist *sg;

	if (cpu_needs_post_dma_flush(dev)) {
		for_each_sg(sglist, sg, nelems, i) {
			__dma_sync(sg_page(sg), sg->offset, sg->length,
				   direction);
		}
	}
	plat_post_dma_flush(dev);
}

static void mips_dma_sync_sg_for_device(struct device *dev,
	struct scatterlist *sglist, int nelems,
	enum dma_data_direction direction)
{
	int i;
	struct scatterlist *sg;

	if (!plat_device_is_coherent(dev)) {
		for_each_sg(sglist, sg, nelems, i) {
			__dma_sync(sg_page(sg), sg->offset, sg->length,
				   direction);
		}
	}
}

static int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
	return 0;
}

static int mips_dma_supported(struct device *dev, u64 mask)
{
	return plat_dma_supported(dev, mask);
}

static void mips_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
			 enum dma_data_direction direction)
{
	BUG_ON(direction == DMA_NONE);

	if (!plat_device_is_coherent(dev))
		__dma_sync_virtual(vaddr, size, direction);
}

static const struct dma_map_ops mips_default_dma_map_ops = {
	.alloc = mips_dma_alloc_coherent,
	.free = mips_dma_free_coherent,
	.mmap = mips_dma_mmap,
	.map_page = mips_dma_map_page,
	.unmap_page = mips_dma_unmap_page,
	.map_sg = mips_dma_map_sg,
	.unmap_sg = mips_dma_unmap_sg,
	.sync_single_for_cpu = mips_dma_sync_single_for_cpu,
	.sync_single_for_device = mips_dma_sync_single_for_device,
	.sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
	.sync_sg_for_device = mips_dma_sync_sg_for_device,
	.mapping_error = mips_dma_mapping_error,
	.dma_supported = mips_dma_supported,
	.cache_sync = mips_dma_cache_sync,
};

const struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
EXPORT_SYMBOL(mips_dma_map_ops);

#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)

static int __init mips_dma_init(void)
{
	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);

	return 0;
}
fs_initcall(mips_dma_init);