aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/pci-dma.c
blob: f581a4b63b43788c2d957cbbdda39f05c57b9e6b (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
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
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
#include <linux/dma-mapping.h>
#include <linux/dmar.h>
#include <linux/bootmem.h>
#include <linux/pci.h>

#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/iommu.h>
#include <asm/calgary.h>
#include <asm/amd_iommu.h>

int forbid_dac __read_mostly;
EXPORT_SYMBOL(forbid_dac);

const struct dma_mapping_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);

static int iommu_sac_force __read_mostly;

#ifdef CONFIG_IOMMU_DEBUG
int panic_on_overflow __read_mostly = 1;
int force_iommu __read_mostly = 1;
#else
int panic_on_overflow __read_mostly = 0;
int force_iommu __read_mostly = 0;
#endif

int iommu_merge __read_mostly = 0;

int no_iommu __read_mostly;
/* Set this to 1 if there is a HW IOMMU in the system */
int iommu_detected __read_mostly = 0;

/* This tells the BIO block layer to assume merging. Default to off
   because we cannot guarantee merging later. */
int iommu_bio_merge __read_mostly = 0;
EXPORT_SYMBOL(iommu_bio_merge);

dma_addr_t bad_dma_address __read_mostly = 0;
EXPORT_SYMBOL(bad_dma_address);

/* Dummy device used for NULL arguments (normally ISA). Better would
   be probably a smaller DMA mask, but this is bug-to-bug compatible
   to older i386. */
struct device fallback_dev = {
	.bus_id = "fallback device",
	.coherent_dma_mask = DMA_32BIT_MASK,
	.dma_mask = &fallback_dev.coherent_dma_mask,
};

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

	*dev->dma_mask = mask;

	return 0;
}
EXPORT_SYMBOL(dma_set_mask);

#ifdef CONFIG_X86_64
static __initdata void *dma32_bootmem_ptr;
static unsigned long dma32_bootmem_size __initdata = (128ULL<<20);

static int __init parse_dma32_size_opt(char *p)
{
	if (!p)
		return -EINVAL;
	dma32_bootmem_size = memparse(p, &p);
	return 0;
}
early_param("dma32_size", parse_dma32_size_opt);

void __init dma32_reserve_bootmem(void)
{
	unsigned long size, align;
	if (max_pfn <= MAX_DMA32_PFN)
		return;

	/*
	 * check aperture_64.c allocate_aperture() for reason about
	 * using 512M as goal
	 */
	align = 64ULL<<20;
	size = round_up(dma32_bootmem_size, align);
	dma32_bootmem_ptr = __alloc_bootmem_nopanic(size, align,
				 512ULL<<20);
	if (dma32_bootmem_ptr)
		dma32_bootmem_size = size;
	else
		dma32_bootmem_size = 0;
}
static void __init dma32_free_bootmem(void)
{

	if (max_pfn <= MAX_DMA32_PFN)
		return;

	if (!dma32_bootmem_ptr)
		return;

	free_bootmem(__pa(dma32_bootmem_ptr), dma32_bootmem_size);

	dma32_bootmem_ptr = NULL;
	dma32_bootmem_size = 0;
}

void __init pci_iommu_alloc(void)
{
	/* free the range so iommu could get some range less than 4G */
	dma32_free_bootmem();
	/*
	 * The order of these functions is important for
	 * fall-back/fail-over reasons
	 */
#ifdef CONFIG_GART_IOMMU
	gart_iommu_hole_init();
#endif

#ifdef CONFIG_CALGARY_IOMMU
	detect_calgary();
#endif

	detect_intel_iommu();

	amd_iommu_detect();

#ifdef CONFIG_SWIOTLB
	pci_swiotlb_init();
#endif
}
#endif

/*
 * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
 * documentation.
 */
static __init int iommu_setup(char *p)
{
	iommu_merge = 1;

	if (!p)
		return -EINVAL;

	while (*p) {
		if (!strncmp(p, "off", 3))
			no_iommu = 1;
		/* gart_parse_options has more force support */
		if (!strncmp(p, "force", 5))
			force_iommu = 1;
		if (!strncmp(p, "noforce", 7)) {
			iommu_merge = 0;
			force_iommu = 0;
		}

		if (!strncmp(p, "biomerge", 8)) {
			iommu_bio_merge = 4096;
			iommu_merge = 1;
			force_iommu = 1;
		}
		if (!strncmp(p, "panic", 5))
			panic_on_overflow = 1;
		if (!strncmp(p, "nopanic", 7))
			panic_on_overflow = 0;
		if (!strncmp(p, "merge", 5)) {
			iommu_merge = 1;
			force_iommu = 1;
		}
		if (!strncmp(p, "nomerge", 7))
			iommu_merge = 0;
		if (!strncmp(p, "forcesac", 8))
			iommu_sac_force = 1;
		if (!strncmp(p, "allowdac", 8))
			forbid_dac = 0;
		if (!strncmp(p, "nodac", 5))
			forbid_dac = -1;
		if (!strncmp(p, "usedac", 6)) {
			forbid_dac = -1;
			return 1;
		}
#ifdef CONFIG_SWIOTLB
		if (!strncmp(p, "soft", 4))
			swiotlb = 1;
#endif

#ifdef CONFIG_GART_IOMMU
		gart_parse_options(p);
#endif

#ifdef CONFIG_CALGARY_IOMMU
		if (!strncmp(p, "calgary", 7))
			use_calgary = 1;
#endif /* CONFIG_CALGARY_IOMMU */

		p += strcspn(p, ",");
		if (*p == ',')
			++p;
	}
	return 0;
}
early_param("iommu", iommu_setup);

#ifdef CONFIG_X86_32
int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
				dma_addr_t device_addr, size_t size, int flags)
{
	void __iomem *mem_base = NULL;
	int pages = size >> PAGE_SHIFT;
	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);

	if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
		goto out;
	if (!size)
		goto out;
	if (dev->dma_mem)
		goto out;

	/* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */

	mem_base = ioremap(bus_addr, size);
	if (!mem_base)
		goto out;

	dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
	if (!dev->dma_mem)
		goto out;
	dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
	if (!dev->dma_mem->bitmap)
		goto free1_out;

	dev->dma_mem->virt_base = mem_base;
	dev->dma_mem->device_base = device_addr;
	dev->dma_mem->size = pages;
	dev->dma_mem->flags = flags;

	if (flags & DMA_MEMORY_MAP)
		return DMA_MEMORY_MAP;

	return DMA_MEMORY_IO;

 free1_out:
	kfree(dev->dma_mem);
 out:
	if (mem_base)
		iounmap(mem_base);
	return 0;
}
EXPORT_SYMBOL(dma_declare_coherent_memory);

void dma_release_declared_memory(struct device *dev)
{
	struct dma_coherent_mem *mem = dev->dma_mem;

	if (!mem)
		return;
	dev->dma_mem = NULL;
	iounmap(mem->virt_base);
	kfree(mem->bitmap);
	kfree(mem);
}
EXPORT_SYMBOL(dma_release_declared_memory);

void *dma_mark_declared_memory_occupied(struct device *dev,
					dma_addr_t device_addr, size_t size)
{
	struct dma_coherent_mem *mem = dev->dma_mem;
	int pos, err;
	int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);

	pages >>= PAGE_SHIFT;

	if (!mem)
		return ERR_PTR(-EINVAL);

	pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
	err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
	if (err != 0)
		return ERR_PTR(err);
	return mem->virt_base + (pos << PAGE_SHIFT);
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);

static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size,
				       dma_addr_t *dma_handle, void **ret)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
	int order = get_order(size);

	if (mem) {
		int page = bitmap_find_free_region(mem->bitmap, mem->size,
						     order);
		if (page >= 0) {
			*dma_handle = mem->device_base + (page << PAGE_SHIFT);
			*ret = mem->virt_base + (page << PAGE_SHIFT);
			memset(*ret, 0, size);
		}
		if (mem->flags & DMA_MEMORY_EXCLUSIVE)
			*ret = NULL;
	}
	return (mem != NULL);
}

static int dma_release_coherent(struct device *dev, int order, void *vaddr)
{
	struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;

	if (mem && vaddr >= mem->virt_base && vaddr <
		   (mem->virt_base + (mem->size << PAGE_SHIFT))) {
		int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;

		bitmap_release_region(mem->bitmap, page, order);
		return 1;
	}
	return 0;
}
#else
#define dma_alloc_from_coherent_mem(dev, size, handle, ret) (0)
#define dma_release_coherent(dev, order, vaddr) (0)
#endif /* CONFIG_X86_32 */

int dma_supported(struct device *dev, u64 mask)
{
#ifdef CONFIG_PCI
	if (mask > 0xffffffff && forbid_dac > 0) {
		printk(KERN_INFO "PCI: Disallowing DAC for device %s\n",
				 dev->bus_id);
		return 0;
	}
#endif

	if (dma_ops->dma_supported)
		return dma_ops->dma_supported(dev, mask);

	/* Copied from i386. Doesn't make much sense, because it will
	   only work for pci_alloc_coherent.
	   The caller just has to use GFP_DMA in this case. */
	if (mask < DMA_24BIT_MASK)
		return 0;

	/* Tell the device to use SAC when IOMMU force is on.  This
	   allows the driver to use cheaper accesses in some cases.

	   Problem with this is that if we overflow the IOMMU area and
	   return DAC as fallback address the device may not handle it
	   correctly.

	   As a special case some controllers have a 39bit address
	   mode that is as efficient as 32bit (aic79xx). Don't force
	   SAC for these.  Assume all masks <= 40 bits are of this
	   type. Normally this doesn't make any difference, but gives
	   more gentle handling of IOMMU overflow. */
	if (iommu_sac_force && (mask >= DMA_40BIT_MASK)) {
		printk(KERN_INFO "%s: Force SAC with mask %Lx\n",
				 dev->bus_id, mask);
		return 0;
	}

	return 1;
}
EXPORT_SYMBOL(dma_supported);

/* Allocate DMA memory on node near device */
static noinline struct page *
dma_alloc_pages(struct device *dev, gfp_t gfp, unsigned order)
{
	int node;

	node = dev_to_node(dev);

	return alloc_pages_node(node, gfp, order);
}

/*
 * Allocate memory for a coherent mapping.
 */
void *
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
		   gfp_t gfp)
{
	void *memory = NULL;
	struct page *page;
	unsigned long dma_mask = 0;
	dma_addr_t bus;
	int noretry = 0;

	/* ignore region specifiers */
	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);

	if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &memory))
		return memory;

	if (!dev) {
		dev = &fallback_dev;
		gfp |= GFP_DMA;
	}
	dma_mask = dev->coherent_dma_mask;
	if (dma_mask == 0)
		dma_mask = (gfp & GFP_DMA) ? DMA_24BIT_MASK : DMA_32BIT_MASK;

	/* Device not DMA able */
	if (dev->dma_mask == NULL)
		return NULL;

	/* Don't invoke OOM killer or retry in lower 16MB DMA zone */
	if (gfp & __GFP_DMA)
		noretry = 1;

#ifdef CONFIG_X86_64
	/* Why <=? Even when the mask is smaller than 4GB it is often
	   larger than 16MB and in this case we have a chance of
	   finding fitting memory in the next higher zone first. If
	   not retry with true GFP_DMA. -AK */
	if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
		gfp |= GFP_DMA32;
		if (dma_mask < DMA_32BIT_MASK)
			noretry = 1;
	}
#endif

 again:
	page = dma_alloc_pages(dev,
		noretry ? gfp | __GFP_NORETRY : gfp, get_order(size));
	if (page == NULL)
		return NULL;

	{
		int high, mmu;
		bus = page_to_phys(page);
		memory = page_address(page);
		high = (bus + size) >= dma_mask;
		mmu = high;
		if (force_iommu && !(gfp & GFP_DMA))
			mmu = 1;
		else if (high) {
			free_pages((unsigned long)memory,
				   get_order(size));

			/* Don't use the 16MB ZONE_DMA unless absolutely
			   needed. It's better to use remapping first. */
			if (dma_mask < DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
				gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
				goto again;
			}

			/* Let low level make its own zone decisions */
			gfp &= ~(GFP_DMA32|GFP_DMA);

			if (dma_ops->alloc_coherent)
				return dma_ops->alloc_coherent(dev, size,
							   dma_handle, gfp);
			return NULL;
		}

		memset(memory, 0, size);
		if (!mmu) {
			*dma_handle = bus;
			return memory;
		}
	}

	if (dma_ops->alloc_coherent) {
		free_pages((unsigned long)memory, get_order(size));
		gfp &= ~(GFP_DMA|GFP_DMA32);
		return dma_ops->alloc_coherent(dev, size, dma_handle, gfp);
	}

	if (dma_ops->map_simple) {
		*dma_handle = dma_ops->map_simple(dev, virt_to_phys(memory),
					      size,
					      PCI_DMA_BIDIRECTIONAL);
		if (*dma_handle != bad_dma_address)
			return memory;
	}

	if (panic_on_overflow)
		panic("dma_alloc_coherent: IOMMU overflow by %lu bytes\n",
		      (unsigned long)size);
	free_pages((unsigned long)memory, get_order(size));
	return NULL;
}
EXPORT_SYMBOL(dma_alloc_coherent);

/*
 * Unmap coherent memory.
 * The caller must ensure that the device has finished accessing the mapping.
 */
void dma_free_coherent(struct device *dev, size_t size,
			 void *vaddr, dma_addr_t bus)
{
	int order = get_order(size);
	WARN_ON(irqs_disabled());	/* for portability */
	if (dma_release_coherent(dev, order, vaddr))
		return;
	if (dma_ops->unmap_single)
		dma_ops->unmap_single(dev, bus, size, 0);
	free_pages((unsigned long)vaddr, order);
}
EXPORT_SYMBOL(dma_free_coherent);

static int __init pci_iommu_init(void)
{
#ifdef CONFIG_CALGARY_IOMMU
	calgary_iommu_init();
#endif

	intel_iommu_init();

	amd_iommu_init();

#ifdef CONFIG_GART_IOMMU
	gart_iommu_init();
#endif

	no_iommu_init();
	return 0;
}

void pci_iommu_shutdown(void)
{
	gart_iommu_shutdown();
}
/* Must execute after PCI subsystem */
fs_initcall(pci_iommu_init);

#ifdef CONFIG_PCI
/* Many VIA bridges seem to corrupt data for DAC. Disable it here */

static __devinit void via_no_dac(struct pci_dev *dev)
{
	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && forbid_dac == 0) {
		printk(KERN_INFO "PCI: VIA PCI bridge detected."
				 "Disabling DAC.\n");
		forbid_dac = 1;
	}
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac);
#endif