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1/*
2 * SWIOTLB-based DMA API implementation
3 *
4 * Copyright (C) 2012 ARM Ltd.
5 * Author: Catalin Marinas <catalin.marinas@arm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/gfp.h>
21#include <linux/acpi.h>
22#include <linux/bootmem.h>
23#include <linux/cache.h>
24#include <linux/export.h>
25#include <linux/slab.h>
26#include <linux/genalloc.h>
27#include <linux/dma-direct.h>
28#include <linux/dma-contiguous.h>
29#include <linux/vmalloc.h>
30#include <linux/swiotlb.h>
31#include <linux/pci.h>
32
33#include <asm/cacheflush.h>
34
35static int swiotlb __ro_after_init;
36
37static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,
38 bool coherent)
39{
40 if (!coherent || (attrs & DMA_ATTR_WRITE_COMBINE))
41 return pgprot_writecombine(prot);
42 return prot;
43}
44
45static struct gen_pool *atomic_pool __ro_after_init;
46
47#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
48static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
49
50static int __init early_coherent_pool(char *p)
51{
52 atomic_pool_size = memparse(p, &p);
53 return 0;
54}
55early_param("coherent_pool", early_coherent_pool);
56
57static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
58{
59 unsigned long val;
60 void *ptr = NULL;
61
62 if (!atomic_pool) {
63 WARN(1, "coherent pool not initialised!\n");
64 return NULL;
65 }
66
67 val = gen_pool_alloc(atomic_pool, size);
68 if (val) {
69 phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
70
71 *ret_page = phys_to_page(phys);
72 ptr = (void *)val;
73 memset(ptr, 0, size);
74 }
75
76 return ptr;
77}
78
79static bool __in_atomic_pool(void *start, size_t size)
80{
81 return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
82}
83
84static int __free_from_pool(void *start, size_t size)
85{
86 if (!__in_atomic_pool(start, size))
87 return 0;
88
89 gen_pool_free(atomic_pool, (unsigned long)start, size);
90
91 return 1;
92}
93
94static void *__dma_alloc(struct device *dev, size_t size,
95 dma_addr_t *dma_handle, gfp_t flags,
96 unsigned long attrs)
97{
98 struct page *page;
99 void *ptr, *coherent_ptr;
100 bool coherent = is_device_dma_coherent(dev);
101 pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, false);
102
103 size = PAGE_ALIGN(size);
104
105 if (!coherent && !gfpflags_allow_blocking(flags)) {
106 struct page *page = NULL;
107 void *addr = __alloc_from_pool(size, &page, flags);
108
109 if (addr)
110 *dma_handle = phys_to_dma(dev, page_to_phys(page));
111
112 return addr;
113 }
114
115 ptr = swiotlb_alloc(dev, size, dma_handle, flags, attrs);
116 if (!ptr)
117 goto no_mem;
118
119 /* no need for non-cacheable mapping if coherent */
120 if (coherent)
121 return ptr;
122
123 /* remove any dirty cache lines on the kernel alias */
124 __dma_flush_area(ptr, size);
125
126 /* create a coherent mapping */
127 page = virt_to_page(ptr);
128 coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
129 prot, __builtin_return_address(0));
130 if (!coherent_ptr)
131 goto no_map;
132
133 return coherent_ptr;
134
135no_map:
136 swiotlb_free(dev, size, ptr, *dma_handle, attrs);
137no_mem:
138 return NULL;
139}
140
141static void __dma_free(struct device *dev, size_t size,
142 void *vaddr, dma_addr_t dma_handle,
143 unsigned long attrs)
144{
145 void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
146
147 size = PAGE_ALIGN(size);
148
149 if (!is_device_dma_coherent(dev)) {
150 if (__free_from_pool(vaddr, size))
151 return;
152 vunmap(vaddr);
153 }
154 swiotlb_free(dev, size, swiotlb_addr, dma_handle, attrs);
155}
156
157static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
158 unsigned long offset, size_t size,
159 enum dma_data_direction dir,
160 unsigned long attrs)
161{
162 dma_addr_t dev_addr;
163
164 dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
165 if (!is_device_dma_coherent(dev) &&
166 (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
167 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
168
169 return dev_addr;
170}
171
172
173static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
174 size_t size, enum dma_data_direction dir,
175 unsigned long attrs)
176{
177 if (!is_device_dma_coherent(dev) &&
178 (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
179 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
180 swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
181}
182
183static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
184 int nelems, enum dma_data_direction dir,
185 unsigned long attrs)
186{
187 struct scatterlist *sg;
188 int i, ret;
189
190 ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
191 if (!is_device_dma_coherent(dev) &&
192 (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
193 for_each_sg(sgl, sg, ret, i)
194 __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
195 sg->length, dir);
196
197 return ret;
198}
199
200static void __swiotlb_unmap_sg_attrs(struct device *dev,
201 struct scatterlist *sgl, int nelems,
202 enum dma_data_direction dir,
203 unsigned long attrs)
204{
205 struct scatterlist *sg;
206 int i;
207
208 if (!is_device_dma_coherent(dev) &&
209 (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
210 for_each_sg(sgl, sg, nelems, i)
211 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
212 sg->length, dir);
213 swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
214}
215
216static void __swiotlb_sync_single_for_cpu(struct device *dev,
217 dma_addr_t dev_addr, size_t size,
218 enum dma_data_direction dir)
219{
220 if (!is_device_dma_coherent(dev))
221 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
222 swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
223}
224
225static void __swiotlb_sync_single_for_device(struct device *dev,
226 dma_addr_t dev_addr, size_t size,
227 enum dma_data_direction dir)
228{
229 swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
230 if (!is_device_dma_coherent(dev))
231 __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
232}
233
234static void __swiotlb_sync_sg_for_cpu(struct device *dev,
235 struct scatterlist *sgl, int nelems,
236 enum dma_data_direction dir)
237{
238 struct scatterlist *sg;
239 int i;
240
241 if (!is_device_dma_coherent(dev))
242 for_each_sg(sgl, sg, nelems, i)
243 __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
244 sg->length, dir);
245 swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
246}
247
248static void __swiotlb_sync_sg_for_device(struct device *dev,
249 struct scatterlist *sgl, int nelems,
250 enum dma_data_direction dir)
251{
252 struct scatterlist *sg;
253 int i;
254
255 swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
256 if (!is_device_dma_coherent(dev))
257 for_each_sg(sgl, sg, nelems, i)
258 __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
259 sg->length, dir);
260}
261
262static int __swiotlb_mmap_pfn(struct vm_area_struct *vma,
263 unsigned long pfn, size_t size)
264{
265 int ret = -ENXIO;
266 unsigned long nr_vma_pages = vma_pages(vma);
267 unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
268 unsigned long off = vma->vm_pgoff;
269
270 if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
271 ret = remap_pfn_range(vma, vma->vm_start,
272 pfn + off,
273 vma->vm_end - vma->vm_start,
274 vma->vm_page_prot);
275 }
276
277 return ret;
278}
279
280static int __swiotlb_mmap(struct device *dev,
281 struct vm_area_struct *vma,
282 void *cpu_addr, dma_addr_t dma_addr, size_t size,
283 unsigned long attrs)
284{
285 int ret;
286 unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
287
288 vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
289 is_device_dma_coherent(dev));
290
291 if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
292 return ret;
293
294 return __swiotlb_mmap_pfn(vma, pfn, size);
295}
296
297static int __swiotlb_get_sgtable_page(struct sg_table *sgt,
298 struct page *page, size_t size)
299{
300 int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
301
302 if (!ret)
303 sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
304
305 return ret;
306}
307
308static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
309 void *cpu_addr, dma_addr_t handle, size_t size,
310 unsigned long attrs)
311{
312 struct page *page = phys_to_page(dma_to_phys(dev, handle));
313
314 return __swiotlb_get_sgtable_page(sgt, page, size);
315}
316
317static int __swiotlb_dma_supported(struct device *hwdev, u64 mask)
318{
319 if (swiotlb)
320 return swiotlb_dma_supported(hwdev, mask);
321 return 1;
322}
323
324static int __swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t addr)
325{
326 if (swiotlb)
327 return swiotlb_dma_mapping_error(hwdev, addr);
328 return 0;
329}
330
331static const struct dma_map_ops arm64_swiotlb_dma_ops = {
332 .alloc = __dma_alloc,
333 .free = __dma_free,
334 .mmap = __swiotlb_mmap,
335 .get_sgtable = __swiotlb_get_sgtable,
336 .map_page = __swiotlb_map_page,
337 .unmap_page = __swiotlb_unmap_page,
338 .map_sg = __swiotlb_map_sg_attrs,
339 .unmap_sg = __swiotlb_unmap_sg_attrs,
340 .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
341 .sync_single_for_device = __swiotlb_sync_single_for_device,
342 .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
343 .sync_sg_for_device = __swiotlb_sync_sg_for_device,
344 .dma_supported = __swiotlb_dma_supported,
345 .mapping_error = __swiotlb_dma_mapping_error,
346};
347
348static int __init atomic_pool_init(void)
349{
350 pgprot_t prot = __pgprot(PROT_NORMAL_NC);
351 unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
352 struct page *page;
353 void *addr;
354 unsigned int pool_size_order = get_order(atomic_pool_size);
355
356 if (dev_get_cma_area(NULL))
357 page = dma_alloc_from_contiguous(NULL, nr_pages,
358 pool_size_order, GFP_KERNEL);
359 else
360 page = alloc_pages(GFP_DMA32, pool_size_order);
361
362 if (page) {
363 int ret;
364 void *page_addr = page_address(page);
365
366 memset(page_addr, 0, atomic_pool_size);
367 __dma_flush_area(page_addr, atomic_pool_size);
368
369 atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
370 if (!atomic_pool)
371 goto free_page;
372
373 addr = dma_common_contiguous_remap(page, atomic_pool_size,
374 VM_USERMAP, prot, atomic_pool_init);
375
376 if (!addr)
377 goto destroy_genpool;
378
379 ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
380 page_to_phys(page),
381 atomic_pool_size, -1);
382 if (ret)
383 goto remove_mapping;
384
385 gen_pool_set_algo(atomic_pool,
386 gen_pool_first_fit_order_align,
387 NULL);
388
389 pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
390 atomic_pool_size / 1024);
391 return 0;
392 }
393 goto out;
394
395remove_mapping:
396 dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
397destroy_genpool:
398 gen_pool_destroy(atomic_pool);
399 atomic_pool = NULL;
400free_page:
401 if (!dma_release_from_contiguous(NULL, page, nr_pages))
402 __free_pages(page, pool_size_order);
403out:
404 pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
405 atomic_pool_size / 1024);
406 return -ENOMEM;
407}
408
409/********************************************
410 * The following APIs are for dummy DMA ops *
411 ********************************************/
412
413static void *__dummy_alloc(struct device *dev, size_t size,
414 dma_addr_t *dma_handle, gfp_t flags,
415 unsigned long attrs)
416{
417 return NULL;
418}
419
420static void __dummy_free(struct device *dev, size_t size,
421 void *vaddr, dma_addr_t dma_handle,
422 unsigned long attrs)
423{
424}
425
426static int __dummy_mmap(struct device *dev,
427 struct vm_area_struct *vma,
428 void *cpu_addr, dma_addr_t dma_addr, size_t size,
429 unsigned long attrs)
430{
431 return -ENXIO;
432}
433
434static dma_addr_t __dummy_map_page(struct device *dev, struct page *page,
435 unsigned long offset, size_t size,
436 enum dma_data_direction dir,
437 unsigned long attrs)
438{
439 return 0;
440}
441
442static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr,
443 size_t size, enum dma_data_direction dir,
444 unsigned long attrs)
445{
446}
447
448static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl,
449 int nelems, enum dma_data_direction dir,
450 unsigned long attrs)
451{
452 return 0;
453}
454
455static void __dummy_unmap_sg(struct device *dev,
456 struct scatterlist *sgl, int nelems,
457 enum dma_data_direction dir,
458 unsigned long attrs)
459{
460}
461
462static void __dummy_sync_single(struct device *dev,
463 dma_addr_t dev_addr, size_t size,
464 enum dma_data_direction dir)
465{
466}
467
468static void __dummy_sync_sg(struct device *dev,
469 struct scatterlist *sgl, int nelems,
470 enum dma_data_direction dir)
471{
472}
473
474static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
475{
476 return 1;
477}
478
479static int __dummy_dma_supported(struct device *hwdev, u64 mask)
480{
481 return 0;
482}
483
484const struct dma_map_ops dummy_dma_ops = {
485 .alloc = __dummy_alloc,
486 .free = __dummy_free,
487 .mmap = __dummy_mmap,
488 .map_page = __dummy_map_page,
489 .unmap_page = __dummy_unmap_page,
490 .map_sg = __dummy_map_sg,
491 .unmap_sg = __dummy_unmap_sg,
492 .sync_single_for_cpu = __dummy_sync_single,
493 .sync_single_for_device = __dummy_sync_single,
494 .sync_sg_for_cpu = __dummy_sync_sg,
495 .sync_sg_for_device = __dummy_sync_sg,
496 .mapping_error = __dummy_mapping_error,
497 .dma_supported = __dummy_dma_supported,
498};
499EXPORT_SYMBOL(dummy_dma_ops);
500
501static int __init arm64_dma_init(void)
502{
503 if (swiotlb_force == SWIOTLB_FORCE ||
504 max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT))
505 swiotlb = 1;
506
507 return atomic_pool_init();
508}
509arch_initcall(arm64_dma_init);
510
511#define PREALLOC_DMA_DEBUG_ENTRIES 4096
512
513static int __init dma_debug_do_init(void)
514{
515 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
516 return 0;
517}
518fs_initcall(dma_debug_do_init);
519
520
521#ifdef CONFIG_IOMMU_DMA
522#include <linux/dma-iommu.h>
523#include <linux/platform_device.h>
524#include <linux/amba/bus.h>
525
526/* Thankfully, all cache ops are by VA so we can ignore phys here */
527static void flush_page(struct device *dev, const void *virt, phys_addr_t phys)
528{
529 __dma_flush_area(virt, PAGE_SIZE);
530}
531
532static void *__iommu_alloc_attrs(struct device *dev, size_t size,
533 dma_addr_t *handle, gfp_t gfp,
534 unsigned long attrs)
535{
536 bool coherent = is_device_dma_coherent(dev);
537 int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
538 size_t iosize = size;
539 void *addr;
540
541 if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n"))
542 return NULL;
543
544 size = PAGE_ALIGN(size);
545
546 /*
547 * Some drivers rely on this, and we probably don't want the
548 * possibility of stale kernel data being read by devices anyway.
549 */
550 gfp |= __GFP_ZERO;
551
552 if (!gfpflags_allow_blocking(gfp)) {
553 struct page *page;
554 /*
555 * In atomic context we can't remap anything, so we'll only
556 * get the virtually contiguous buffer we need by way of a
557 * physically contiguous allocation.
558 */
559 if (coherent) {
560 page = alloc_pages(gfp, get_order(size));
561 addr = page ? page_address(page) : NULL;
562 } else {
563 addr = __alloc_from_pool(size, &page, gfp);
564 }
565 if (!addr)
566 return NULL;
567
568 *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
569 if (iommu_dma_mapping_error(dev, *handle)) {
570 if (coherent)
571 __free_pages(page, get_order(size));
572 else
573 __free_from_pool(addr, size);
574 addr = NULL;
575 }
576 } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
577 pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent);
578 struct page *page;
579
580 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
581 get_order(size), gfp);
582 if (!page)
583 return NULL;
584
585 *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
586 if (iommu_dma_mapping_error(dev, *handle)) {
587 dma_release_from_contiguous(dev, page,
588 size >> PAGE_SHIFT);
589 return NULL;
590 }
591 if (!coherent)
592 __dma_flush_area(page_to_virt(page), iosize);
593
594 addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
595 prot,
596 __builtin_return_address(0));
597 if (!addr) {
598 iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs);
599 dma_release_from_contiguous(dev, page,
600 size >> PAGE_SHIFT);
601 }
602 } else {
603 pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent);
604 struct page **pages;
605
606 pages = iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
607 handle, flush_page);
608 if (!pages)
609 return NULL;
610
611 addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
612 __builtin_return_address(0));
613 if (!addr)
614 iommu_dma_free(dev, pages, iosize, handle);
615 }
616 return addr;
617}
618
619static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
620 dma_addr_t handle, unsigned long attrs)
621{
622 size_t iosize = size;
623
624 size = PAGE_ALIGN(size);
625 /*
626 * @cpu_addr will be one of 4 things depending on how it was allocated:
627 * - A remapped array of pages for contiguous allocations.
628 * - A remapped array of pages from iommu_dma_alloc(), for all
629 * non-atomic allocations.
630 * - A non-cacheable alias from the atomic pool, for atomic
631 * allocations by non-coherent devices.
632 * - A normal lowmem address, for atomic allocations by
633 * coherent devices.
634 * Hence how dodgy the below logic looks...
635 */
636 if (__in_atomic_pool(cpu_addr, size)) {
637 iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
638 __free_from_pool(cpu_addr, size);
639 } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
640 struct page *page = vmalloc_to_page(cpu_addr);
641
642 iommu_dma_unmap_page(dev, handle, iosize, 0, attrs);
643 dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
644 dma_common_free_remap(cpu_addr, size, VM_USERMAP);
645 } else if (is_vmalloc_addr(cpu_addr)){
646 struct vm_struct *area = find_vm_area(cpu_addr);
647
648 if (WARN_ON(!area || !area->pages))
649 return;
650 iommu_dma_free(dev, area->pages, iosize, &handle);
651 dma_common_free_remap(cpu_addr, size, VM_USERMAP);
652 } else {
653 iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
654 __free_pages(virt_to_page(cpu_addr), get_order(size));
655 }
656}
657
658static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
659 void *cpu_addr, dma_addr_t dma_addr, size_t size,
660 unsigned long attrs)
661{
662 struct vm_struct *area;
663 int ret;
664
665 vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
666 is_device_dma_coherent(dev));
667
668 if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
669 return ret;
670
671 if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
672 /*
673 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
674 * hence in the vmalloc space.
675 */
676 unsigned long pfn = vmalloc_to_pfn(cpu_addr);
677 return __swiotlb_mmap_pfn(vma, pfn, size);
678 }
679
680 area = find_vm_area(cpu_addr);
681 if (WARN_ON(!area || !area->pages))
682 return -ENXIO;
683
684 return iommu_dma_mmap(area->pages, size, vma);
685}
686
687static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
688 void *cpu_addr, dma_addr_t dma_addr,
689 size_t size, unsigned long attrs)
690{
691 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
692 struct vm_struct *area = find_vm_area(cpu_addr);
693
694 if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
695 /*
696 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
697 * hence in the vmalloc space.
698 */
699 struct page *page = vmalloc_to_page(cpu_addr);
700 return __swiotlb_get_sgtable_page(sgt, page, size);
701 }
702
703 if (WARN_ON(!area || !area->pages))
704 return -ENXIO;
705
706 return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size,
707 GFP_KERNEL);
708}
709
710static void __iommu_sync_single_for_cpu(struct device *dev,
711 dma_addr_t dev_addr, size_t size,
712 enum dma_data_direction dir)
713{
714 phys_addr_t phys;
715
716 if (is_device_dma_coherent(dev))
717 return;
718
719 phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr);
720 __dma_unmap_area(phys_to_virt(phys), size, dir);
721}
722
723static void __iommu_sync_single_for_device(struct device *dev,
724 dma_addr_t dev_addr, size_t size,
725 enum dma_data_direction dir)
726{
727 phys_addr_t phys;
728
729 if (is_device_dma_coherent(dev))
730 return;
731
732 phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr);
733 __dma_map_area(phys_to_virt(phys), size, dir);
734}
735
736static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
737 unsigned long offset, size_t size,
738 enum dma_data_direction dir,
739 unsigned long attrs)
740{
741 bool coherent = is_device_dma_coherent(dev);
742 int prot = dma_info_to_prot(dir, coherent, attrs);
743 dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
744
745 if (!iommu_dma_mapping_error(dev, dev_addr) &&
746 (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
747 __iommu_sync_single_for_device(dev, dev_addr, size, dir);
748
749 return dev_addr;
750}
751
752static void __iommu_unmap_page(struct device *dev, dma_addr_t dev_addr,
753 size_t size, enum dma_data_direction dir,
754 unsigned long attrs)
755{
756 if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
757 __iommu_sync_single_for_cpu(dev, dev_addr, size, dir);
758
759 iommu_dma_unmap_page(dev, dev_addr, size, dir, attrs);
760}
761
762static void __iommu_sync_sg_for_cpu(struct device *dev,
763 struct scatterlist *sgl, int nelems,
764 enum dma_data_direction dir)
765{
766 struct scatterlist *sg;
767 int i;
768
769 if (is_device_dma_coherent(dev))
770 return;
771
772 for_each_sg(sgl, sg, nelems, i)
773 __dma_unmap_area(sg_virt(sg), sg->length, dir);
774}
775
776static void __iommu_sync_sg_for_device(struct device *dev,
777 struct scatterlist *sgl, int nelems,
778 enum dma_data_direction dir)
779{
780 struct scatterlist *sg;
781 int i;
782
783 if (is_device_dma_coherent(dev))
784 return;
785
786 for_each_sg(sgl, sg, nelems, i)
787 __dma_map_area(sg_virt(sg), sg->length, dir);
788}
789
790static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
791 int nelems, enum dma_data_direction dir,
792 unsigned long attrs)
793{
794 bool coherent = is_device_dma_coherent(dev);
795
796 if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
797 __iommu_sync_sg_for_device(dev, sgl, nelems, dir);
798
799 return iommu_dma_map_sg(dev, sgl, nelems,
800 dma_info_to_prot(dir, coherent, attrs));
801}
802
803static void __iommu_unmap_sg_attrs(struct device *dev,
804 struct scatterlist *sgl, int nelems,
805 enum dma_data_direction dir,
806 unsigned long attrs)
807{
808 if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
809 __iommu_sync_sg_for_cpu(dev, sgl, nelems, dir);
810
811 iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs);
812}
813
814static const struct dma_map_ops iommu_dma_ops = {
815 .alloc = __iommu_alloc_attrs,
816 .free = __iommu_free_attrs,
817 .mmap = __iommu_mmap_attrs,
818 .get_sgtable = __iommu_get_sgtable,
819 .map_page = __iommu_map_page,
820 .unmap_page = __iommu_unmap_page,
821 .map_sg = __iommu_map_sg_attrs,
822 .unmap_sg = __iommu_unmap_sg_attrs,
823 .sync_single_for_cpu = __iommu_sync_single_for_cpu,
824 .sync_single_for_device = __iommu_sync_single_for_device,
825 .sync_sg_for_cpu = __iommu_sync_sg_for_cpu,
826 .sync_sg_for_device = __iommu_sync_sg_for_device,
827 .map_resource = iommu_dma_map_resource,
828 .unmap_resource = iommu_dma_unmap_resource,
829 .mapping_error = iommu_dma_mapping_error,
830};
831
832static int __init __iommu_dma_init(void)
833{
834 return iommu_dma_init();
835}
836arch_initcall(__iommu_dma_init);
837
838static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
839 const struct iommu_ops *ops)
840{
841 struct iommu_domain *domain;
842
843 if (!ops)
844 return;
845
846 /*
847 * The IOMMU core code allocates the default DMA domain, which the
848 * underlying IOMMU driver needs to support via the dma-iommu layer.
849 */
850 domain = iommu_get_domain_for_dev(dev);
851
852 if (!domain)
853 goto out_err;
854
855 if (domain->type == IOMMU_DOMAIN_DMA) {
856 if (iommu_dma_init_domain(domain, dma_base, size, dev))
857 goto out_err;
858
859 dev->dma_ops = &iommu_dma_ops;
860 }
861
862 return;
863
864out_err:
865 pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
866 dev_name(dev));
867}
868
869void arch_teardown_dma_ops(struct device *dev)
870{
871 dev->dma_ops = NULL;
872}
873
874#else
875
876static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
877 const struct iommu_ops *iommu)
878{ }
879
880#endif /* CONFIG_IOMMU_DMA */
881
882void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
883 const struct iommu_ops *iommu, bool coherent)
884{
885 if (!dev->dma_ops)
886 dev->dma_ops = &arm64_swiotlb_dma_ops;
887
888 dev->archdata.dma_coherent = coherent;
889 __iommu_setup_dma_ops(dev, dma_base, size, iommu);
890
891#ifdef CONFIG_XEN
892 if (xen_initial_domain()) {
893 dev->archdata.dev_dma_ops = dev->dma_ops;
894 dev->dma_ops = xen_dma_ops;
895 }
896#endif
897}