Commit | Line | Data |
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0db2e5d1 RM |
1 | /* |
2 | * A fairly generic DMA-API to IOMMU-API glue layer. | |
3 | * | |
4 | * Copyright (C) 2014-2015 ARM Ltd. | |
5 | * | |
6 | * based in part on arch/arm/mm/dma-mapping.c: | |
7 | * Copyright (C) 2000-2004 Russell King | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
20 | */ | |
21 | ||
22 | #include <linux/device.h> | |
23 | #include <linux/dma-iommu.h> | |
5b11e9cd | 24 | #include <linux/gfp.h> |
0db2e5d1 RM |
25 | #include <linux/huge_mm.h> |
26 | #include <linux/iommu.h> | |
27 | #include <linux/iova.h> | |
44bb7e24 | 28 | #include <linux/irq.h> |
0db2e5d1 | 29 | #include <linux/mm.h> |
fade1ec0 | 30 | #include <linux/pci.h> |
5b11e9cd RM |
31 | #include <linux/scatterlist.h> |
32 | #include <linux/vmalloc.h> | |
0db2e5d1 | 33 | |
44bb7e24 RM |
34 | struct iommu_dma_msi_page { |
35 | struct list_head list; | |
36 | dma_addr_t iova; | |
37 | phys_addr_t phys; | |
38 | }; | |
39 | ||
fdbe574e RM |
40 | enum iommu_dma_cookie_type { |
41 | IOMMU_DMA_IOVA_COOKIE, | |
42 | IOMMU_DMA_MSI_COOKIE, | |
43 | }; | |
44 | ||
44bb7e24 | 45 | struct iommu_dma_cookie { |
fdbe574e RM |
46 | enum iommu_dma_cookie_type type; |
47 | union { | |
48 | /* Full allocator for IOMMU_DMA_IOVA_COOKIE */ | |
49 | struct iova_domain iovad; | |
50 | /* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */ | |
51 | dma_addr_t msi_iova; | |
52 | }; | |
53 | struct list_head msi_page_list; | |
54 | spinlock_t msi_lock; | |
44bb7e24 RM |
55 | }; |
56 | ||
fdbe574e RM |
57 | static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie) |
58 | { | |
59 | if (cookie->type == IOMMU_DMA_IOVA_COOKIE) | |
60 | return cookie->iovad.granule; | |
61 | return PAGE_SIZE; | |
62 | } | |
63 | ||
fdbe574e RM |
64 | static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type) |
65 | { | |
66 | struct iommu_dma_cookie *cookie; | |
67 | ||
68 | cookie = kzalloc(sizeof(*cookie), GFP_KERNEL); | |
69 | if (cookie) { | |
70 | spin_lock_init(&cookie->msi_lock); | |
71 | INIT_LIST_HEAD(&cookie->msi_page_list); | |
72 | cookie->type = type; | |
73 | } | |
74 | return cookie; | |
44bb7e24 RM |
75 | } |
76 | ||
0db2e5d1 RM |
77 | int iommu_dma_init(void) |
78 | { | |
79 | return iova_cache_get(); | |
80 | } | |
81 | ||
82 | /** | |
83 | * iommu_get_dma_cookie - Acquire DMA-API resources for a domain | |
84 | * @domain: IOMMU domain to prepare for DMA-API usage | |
85 | * | |
86 | * IOMMU drivers should normally call this from their domain_alloc | |
87 | * callback when domain->type == IOMMU_DOMAIN_DMA. | |
88 | */ | |
89 | int iommu_get_dma_cookie(struct iommu_domain *domain) | |
fdbe574e RM |
90 | { |
91 | if (domain->iova_cookie) | |
92 | return -EEXIST; | |
93 | ||
94 | domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE); | |
95 | if (!domain->iova_cookie) | |
96 | return -ENOMEM; | |
97 | ||
98 | return 0; | |
99 | } | |
100 | EXPORT_SYMBOL(iommu_get_dma_cookie); | |
101 | ||
102 | /** | |
103 | * iommu_get_msi_cookie - Acquire just MSI remapping resources | |
104 | * @domain: IOMMU domain to prepare | |
105 | * @base: Start address of IOVA region for MSI mappings | |
106 | * | |
107 | * Users who manage their own IOVA allocation and do not want DMA API support, | |
108 | * but would still like to take advantage of automatic MSI remapping, can use | |
109 | * this to initialise their own domain appropriately. Users should reserve a | |
110 | * contiguous IOVA region, starting at @base, large enough to accommodate the | |
111 | * number of PAGE_SIZE mappings necessary to cover every MSI doorbell address | |
112 | * used by the devices attached to @domain. | |
113 | */ | |
114 | int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base) | |
0db2e5d1 | 115 | { |
44bb7e24 | 116 | struct iommu_dma_cookie *cookie; |
0db2e5d1 | 117 | |
fdbe574e RM |
118 | if (domain->type != IOMMU_DOMAIN_UNMANAGED) |
119 | return -EINVAL; | |
120 | ||
0db2e5d1 RM |
121 | if (domain->iova_cookie) |
122 | return -EEXIST; | |
123 | ||
fdbe574e | 124 | cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE); |
44bb7e24 RM |
125 | if (!cookie) |
126 | return -ENOMEM; | |
0db2e5d1 | 127 | |
fdbe574e | 128 | cookie->msi_iova = base; |
44bb7e24 RM |
129 | domain->iova_cookie = cookie; |
130 | return 0; | |
0db2e5d1 | 131 | } |
fdbe574e | 132 | EXPORT_SYMBOL(iommu_get_msi_cookie); |
0db2e5d1 RM |
133 | |
134 | /** | |
135 | * iommu_put_dma_cookie - Release a domain's DMA mapping resources | |
fdbe574e RM |
136 | * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() or |
137 | * iommu_get_msi_cookie() | |
0db2e5d1 RM |
138 | * |
139 | * IOMMU drivers should normally call this from their domain_free callback. | |
140 | */ | |
141 | void iommu_put_dma_cookie(struct iommu_domain *domain) | |
142 | { | |
44bb7e24 RM |
143 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
144 | struct iommu_dma_msi_page *msi, *tmp; | |
0db2e5d1 | 145 | |
44bb7e24 | 146 | if (!cookie) |
0db2e5d1 RM |
147 | return; |
148 | ||
fdbe574e | 149 | if (cookie->type == IOMMU_DMA_IOVA_COOKIE && cookie->iovad.granule) |
44bb7e24 RM |
150 | put_iova_domain(&cookie->iovad); |
151 | ||
152 | list_for_each_entry_safe(msi, tmp, &cookie->msi_page_list, list) { | |
153 | list_del(&msi->list); | |
154 | kfree(msi); | |
155 | } | |
156 | kfree(cookie); | |
0db2e5d1 RM |
157 | domain->iova_cookie = NULL; |
158 | } | |
159 | EXPORT_SYMBOL(iommu_put_dma_cookie); | |
160 | ||
273df963 RM |
161 | /** |
162 | * iommu_dma_get_resv_regions - Reserved region driver helper | |
163 | * @dev: Device from iommu_get_resv_regions() | |
164 | * @list: Reserved region list from iommu_get_resv_regions() | |
165 | * | |
166 | * IOMMU drivers can use this to implement their .get_resv_regions callback | |
167 | * for general non-IOMMU-specific reservations. Currently, this covers host | |
168 | * bridge windows for PCI devices. | |
169 | */ | |
170 | void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list) | |
fade1ec0 | 171 | { |
273df963 | 172 | struct pci_host_bridge *bridge; |
fade1ec0 | 173 | struct resource_entry *window; |
fade1ec0 | 174 | |
273df963 RM |
175 | if (!dev_is_pci(dev)) |
176 | return; | |
177 | ||
178 | bridge = pci_find_host_bridge(to_pci_dev(dev)->bus); | |
fade1ec0 | 179 | resource_list_for_each_entry(window, &bridge->windows) { |
273df963 RM |
180 | struct iommu_resv_region *region; |
181 | phys_addr_t start; | |
182 | size_t length; | |
183 | ||
938f1bbe | 184 | if (resource_type(window->res) != IORESOURCE_MEM) |
fade1ec0 RM |
185 | continue; |
186 | ||
273df963 RM |
187 | start = window->res->start - window->offset; |
188 | length = window->res->end - window->res->start + 1; | |
189 | region = iommu_alloc_resv_region(start, length, 0, | |
190 | IOMMU_RESV_RESERVED); | |
191 | if (!region) | |
192 | return; | |
193 | ||
194 | list_add_tail(®ion->list, list); | |
fade1ec0 RM |
195 | } |
196 | } | |
273df963 | 197 | EXPORT_SYMBOL(iommu_dma_get_resv_regions); |
fade1ec0 | 198 | |
7c1b058c RM |
199 | static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie, |
200 | phys_addr_t start, phys_addr_t end) | |
201 | { | |
202 | struct iova_domain *iovad = &cookie->iovad; | |
203 | struct iommu_dma_msi_page *msi_page; | |
204 | int i, num_pages; | |
205 | ||
206 | start -= iova_offset(iovad, start); | |
207 | num_pages = iova_align(iovad, end - start) >> iova_shift(iovad); | |
208 | ||
209 | msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL); | |
210 | if (!msi_page) | |
211 | return -ENOMEM; | |
212 | ||
213 | for (i = 0; i < num_pages; i++) { | |
214 | msi_page[i].phys = start; | |
215 | msi_page[i].iova = start; | |
216 | INIT_LIST_HEAD(&msi_page[i].list); | |
217 | list_add(&msi_page[i].list, &cookie->msi_page_list); | |
218 | start += iovad->granule; | |
219 | } | |
220 | ||
221 | return 0; | |
222 | } | |
223 | ||
224 | static int iova_reserve_iommu_regions(struct device *dev, | |
225 | struct iommu_domain *domain) | |
226 | { | |
227 | struct iommu_dma_cookie *cookie = domain->iova_cookie; | |
228 | struct iova_domain *iovad = &cookie->iovad; | |
229 | struct iommu_resv_region *region; | |
230 | LIST_HEAD(resv_regions); | |
231 | int ret = 0; | |
232 | ||
7c1b058c RM |
233 | iommu_get_resv_regions(dev, &resv_regions); |
234 | list_for_each_entry(region, &resv_regions, list) { | |
235 | unsigned long lo, hi; | |
236 | ||
237 | /* We ARE the software that manages these! */ | |
238 | if (region->type == IOMMU_RESV_SW_MSI) | |
239 | continue; | |
240 | ||
241 | lo = iova_pfn(iovad, region->start); | |
242 | hi = iova_pfn(iovad, region->start + region->length - 1); | |
243 | reserve_iova(iovad, lo, hi); | |
244 | ||
245 | if (region->type == IOMMU_RESV_MSI) | |
246 | ret = cookie_init_hw_msi_region(cookie, region->start, | |
247 | region->start + region->length); | |
248 | if (ret) | |
249 | break; | |
250 | } | |
251 | iommu_put_resv_regions(dev, &resv_regions); | |
252 | ||
253 | return ret; | |
254 | } | |
255 | ||
0db2e5d1 RM |
256 | /** |
257 | * iommu_dma_init_domain - Initialise a DMA mapping domain | |
258 | * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() | |
259 | * @base: IOVA at which the mappable address space starts | |
260 | * @size: Size of IOVA space | |
fade1ec0 | 261 | * @dev: Device the domain is being initialised for |
0db2e5d1 RM |
262 | * |
263 | * @base and @size should be exact multiples of IOMMU page granularity to | |
264 | * avoid rounding surprises. If necessary, we reserve the page at address 0 | |
265 | * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but | |
266 | * any change which could make prior IOVAs invalid will fail. | |
267 | */ | |
fade1ec0 RM |
268 | int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, |
269 | u64 size, struct device *dev) | |
0db2e5d1 | 270 | { |
fdbe574e RM |
271 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
272 | struct iova_domain *iovad = &cookie->iovad; | |
0db2e5d1 RM |
273 | unsigned long order, base_pfn, end_pfn; |
274 | ||
fdbe574e RM |
275 | if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE) |
276 | return -EINVAL; | |
0db2e5d1 RM |
277 | |
278 | /* Use the smallest supported page size for IOVA granularity */ | |
d16e0faa | 279 | order = __ffs(domain->pgsize_bitmap); |
0db2e5d1 RM |
280 | base_pfn = max_t(unsigned long, 1, base >> order); |
281 | end_pfn = (base + size - 1) >> order; | |
282 | ||
283 | /* Check the domain allows at least some access to the device... */ | |
284 | if (domain->geometry.force_aperture) { | |
285 | if (base > domain->geometry.aperture_end || | |
286 | base + size <= domain->geometry.aperture_start) { | |
287 | pr_warn("specified DMA range outside IOMMU capability\n"); | |
288 | return -EFAULT; | |
289 | } | |
290 | /* ...then finally give it a kicking to make sure it fits */ | |
291 | base_pfn = max_t(unsigned long, base_pfn, | |
292 | domain->geometry.aperture_start >> order); | |
293 | end_pfn = min_t(unsigned long, end_pfn, | |
294 | domain->geometry.aperture_end >> order); | |
295 | } | |
f51d7bb7 RM |
296 | /* |
297 | * PCI devices may have larger DMA masks, but still prefer allocating | |
298 | * within a 32-bit mask to avoid DAC addressing. Such limitations don't | |
299 | * apply to the typical platform device, so for those we may as well | |
300 | * leave the cache limit at the top of their range to save an rb_last() | |
301 | * traversal on every allocation. | |
302 | */ | |
7c1b058c | 303 | if (dev && dev_is_pci(dev)) |
f51d7bb7 | 304 | end_pfn &= DMA_BIT_MASK(32) >> order; |
0db2e5d1 | 305 | |
f51d7bb7 | 306 | /* start_pfn is always nonzero for an already-initialised domain */ |
0db2e5d1 RM |
307 | if (iovad->start_pfn) { |
308 | if (1UL << order != iovad->granule || | |
f51d7bb7 | 309 | base_pfn != iovad->start_pfn) { |
0db2e5d1 RM |
310 | pr_warn("Incompatible range for DMA domain\n"); |
311 | return -EFAULT; | |
312 | } | |
f51d7bb7 RM |
313 | /* |
314 | * If we have devices with different DMA masks, move the free | |
315 | * area cache limit down for the benefit of the smaller one. | |
316 | */ | |
317 | iovad->dma_32bit_pfn = min(end_pfn, iovad->dma_32bit_pfn); | |
7c1b058c RM |
318 | |
319 | return 0; | |
0db2e5d1 | 320 | } |
7c1b058c RM |
321 | |
322 | init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn); | |
323 | if (!dev) | |
324 | return 0; | |
325 | ||
326 | return iova_reserve_iommu_regions(dev, domain); | |
0db2e5d1 RM |
327 | } |
328 | EXPORT_SYMBOL(iommu_dma_init_domain); | |
329 | ||
330 | /** | |
737c85ca MH |
331 | * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API |
332 | * page flags. | |
0db2e5d1 RM |
333 | * @dir: Direction of DMA transfer |
334 | * @coherent: Is the DMA master cache-coherent? | |
737c85ca | 335 | * @attrs: DMA attributes for the mapping |
0db2e5d1 RM |
336 | * |
337 | * Return: corresponding IOMMU API page protection flags | |
338 | */ | |
737c85ca MH |
339 | int dma_info_to_prot(enum dma_data_direction dir, bool coherent, |
340 | unsigned long attrs) | |
0db2e5d1 RM |
341 | { |
342 | int prot = coherent ? IOMMU_CACHE : 0; | |
343 | ||
737c85ca MH |
344 | if (attrs & DMA_ATTR_PRIVILEGED) |
345 | prot |= IOMMU_PRIV; | |
346 | ||
0db2e5d1 RM |
347 | switch (dir) { |
348 | case DMA_BIDIRECTIONAL: | |
349 | return prot | IOMMU_READ | IOMMU_WRITE; | |
350 | case DMA_TO_DEVICE: | |
351 | return prot | IOMMU_READ; | |
352 | case DMA_FROM_DEVICE: | |
353 | return prot | IOMMU_WRITE; | |
354 | default: | |
355 | return 0; | |
356 | } | |
357 | } | |
358 | ||
842fe519 RM |
359 | static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain, |
360 | size_t size, dma_addr_t dma_limit, struct device *dev) | |
0db2e5d1 | 361 | { |
a44e6657 RM |
362 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
363 | struct iova_domain *iovad = &cookie->iovad; | |
364 | unsigned long shift, iova_len; | |
122fac03 | 365 | struct iova *iova = NULL; |
0db2e5d1 | 366 | |
a44e6657 RM |
367 | if (cookie->type == IOMMU_DMA_MSI_COOKIE) { |
368 | cookie->msi_iova += size; | |
369 | return cookie->msi_iova - size; | |
370 | } | |
371 | ||
372 | shift = iova_shift(iovad); | |
373 | iova_len = size >> shift; | |
374 | ||
c987ff0d RM |
375 | if (domain->geometry.force_aperture) |
376 | dma_limit = min(dma_limit, domain->geometry.aperture_end); | |
122fac03 RM |
377 | |
378 | /* Try to get PCI devices a SAC address */ | |
379 | if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev)) | |
842fe519 | 380 | iova = alloc_iova(iovad, iova_len, DMA_BIT_MASK(32) >> shift, |
122fac03 | 381 | true); |
0db2e5d1 RM |
382 | /* |
383 | * Enforce size-alignment to be safe - there could perhaps be an | |
384 | * attribute to control this per-device, or at least per-domain... | |
385 | */ | |
122fac03 | 386 | if (!iova) |
842fe519 | 387 | iova = alloc_iova(iovad, iova_len, dma_limit >> shift, true); |
122fac03 | 388 | |
842fe519 | 389 | return (dma_addr_t)iova->pfn_lo << shift; |
0db2e5d1 RM |
390 | } |
391 | ||
842fe519 RM |
392 | static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie, |
393 | dma_addr_t iova, size_t size) | |
0db2e5d1 | 394 | { |
842fe519 RM |
395 | struct iova_domain *iovad = &cookie->iovad; |
396 | struct iova *iova_rbnode; | |
0db2e5d1 | 397 | |
a44e6657 RM |
398 | /* The MSI case is only ever cleaning up its most recent allocation */ |
399 | if (cookie->type == IOMMU_DMA_MSI_COOKIE) { | |
400 | cookie->msi_iova -= size; | |
401 | return; | |
402 | } | |
403 | ||
842fe519 RM |
404 | iova_rbnode = find_iova(iovad, iova_pfn(iovad, iova)); |
405 | if (WARN_ON(!iova_rbnode)) | |
0db2e5d1 RM |
406 | return; |
407 | ||
842fe519 RM |
408 | __free_iova(iovad, iova_rbnode); |
409 | } | |
410 | ||
411 | static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr, | |
412 | size_t size) | |
413 | { | |
a44e6657 RM |
414 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
415 | struct iova_domain *iovad = &cookie->iovad; | |
842fe519 RM |
416 | size_t iova_off = iova_offset(iovad, dma_addr); |
417 | ||
418 | dma_addr -= iova_off; | |
419 | size = iova_align(iovad, size + iova_off); | |
420 | ||
421 | WARN_ON(iommu_unmap(domain, dma_addr, size) != size); | |
a44e6657 | 422 | iommu_dma_free_iova(cookie, dma_addr, size); |
0db2e5d1 RM |
423 | } |
424 | ||
425 | static void __iommu_dma_free_pages(struct page **pages, int count) | |
426 | { | |
427 | while (count--) | |
428 | __free_page(pages[count]); | |
429 | kvfree(pages); | |
430 | } | |
431 | ||
3b6b7e19 RM |
432 | static struct page **__iommu_dma_alloc_pages(unsigned int count, |
433 | unsigned long order_mask, gfp_t gfp) | |
0db2e5d1 RM |
434 | { |
435 | struct page **pages; | |
436 | unsigned int i = 0, array_size = count * sizeof(*pages); | |
3b6b7e19 RM |
437 | |
438 | order_mask &= (2U << MAX_ORDER) - 1; | |
439 | if (!order_mask) | |
440 | return NULL; | |
0db2e5d1 RM |
441 | |
442 | if (array_size <= PAGE_SIZE) | |
443 | pages = kzalloc(array_size, GFP_KERNEL); | |
444 | else | |
445 | pages = vzalloc(array_size); | |
446 | if (!pages) | |
447 | return NULL; | |
448 | ||
449 | /* IOMMU can map any pages, so himem can also be used here */ | |
450 | gfp |= __GFP_NOWARN | __GFP_HIGHMEM; | |
451 | ||
452 | while (count) { | |
453 | struct page *page = NULL; | |
3b6b7e19 | 454 | unsigned int order_size; |
0db2e5d1 RM |
455 | |
456 | /* | |
457 | * Higher-order allocations are a convenience rather | |
458 | * than a necessity, hence using __GFP_NORETRY until | |
3b6b7e19 | 459 | * falling back to minimum-order allocations. |
0db2e5d1 | 460 | */ |
3b6b7e19 RM |
461 | for (order_mask &= (2U << __fls(count)) - 1; |
462 | order_mask; order_mask &= ~order_size) { | |
463 | unsigned int order = __fls(order_mask); | |
464 | ||
465 | order_size = 1U << order; | |
466 | page = alloc_pages((order_mask - order_size) ? | |
467 | gfp | __GFP_NORETRY : gfp, order); | |
0db2e5d1 RM |
468 | if (!page) |
469 | continue; | |
3b6b7e19 RM |
470 | if (!order) |
471 | break; | |
472 | if (!PageCompound(page)) { | |
0db2e5d1 RM |
473 | split_page(page, order); |
474 | break; | |
3b6b7e19 RM |
475 | } else if (!split_huge_page(page)) { |
476 | break; | |
0db2e5d1 | 477 | } |
3b6b7e19 | 478 | __free_pages(page, order); |
0db2e5d1 | 479 | } |
0db2e5d1 RM |
480 | if (!page) { |
481 | __iommu_dma_free_pages(pages, i); | |
482 | return NULL; | |
483 | } | |
3b6b7e19 RM |
484 | count -= order_size; |
485 | while (order_size--) | |
0db2e5d1 RM |
486 | pages[i++] = page++; |
487 | } | |
488 | return pages; | |
489 | } | |
490 | ||
491 | /** | |
492 | * iommu_dma_free - Free a buffer allocated by iommu_dma_alloc() | |
493 | * @dev: Device which owns this buffer | |
494 | * @pages: Array of buffer pages as returned by iommu_dma_alloc() | |
495 | * @size: Size of buffer in bytes | |
496 | * @handle: DMA address of buffer | |
497 | * | |
498 | * Frees both the pages associated with the buffer, and the array | |
499 | * describing them | |
500 | */ | |
501 | void iommu_dma_free(struct device *dev, struct page **pages, size_t size, | |
502 | dma_addr_t *handle) | |
503 | { | |
842fe519 | 504 | __iommu_dma_unmap(iommu_get_domain_for_dev(dev), *handle, size); |
0db2e5d1 RM |
505 | __iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT); |
506 | *handle = DMA_ERROR_CODE; | |
507 | } | |
508 | ||
509 | /** | |
510 | * iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space | |
511 | * @dev: Device to allocate memory for. Must be a real device | |
512 | * attached to an iommu_dma_domain | |
513 | * @size: Size of buffer in bytes | |
514 | * @gfp: Allocation flags | |
3b6b7e19 | 515 | * @attrs: DMA attributes for this allocation |
0db2e5d1 RM |
516 | * @prot: IOMMU mapping flags |
517 | * @handle: Out argument for allocated DMA handle | |
518 | * @flush_page: Arch callback which must ensure PAGE_SIZE bytes from the | |
519 | * given VA/PA are visible to the given non-coherent device. | |
520 | * | |
521 | * If @size is less than PAGE_SIZE, then a full CPU page will be allocated, | |
522 | * but an IOMMU which supports smaller pages might not map the whole thing. | |
523 | * | |
524 | * Return: Array of struct page pointers describing the buffer, | |
525 | * or NULL on failure. | |
526 | */ | |
3b6b7e19 | 527 | struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp, |
00085f1e | 528 | unsigned long attrs, int prot, dma_addr_t *handle, |
0db2e5d1 RM |
529 | void (*flush_page)(struct device *, const void *, phys_addr_t)) |
530 | { | |
531 | struct iommu_domain *domain = iommu_get_domain_for_dev(dev); | |
842fe519 RM |
532 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
533 | struct iova_domain *iovad = &cookie->iovad; | |
0db2e5d1 RM |
534 | struct page **pages; |
535 | struct sg_table sgt; | |
842fe519 | 536 | dma_addr_t iova; |
3b6b7e19 | 537 | unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap; |
0db2e5d1 RM |
538 | |
539 | *handle = DMA_ERROR_CODE; | |
540 | ||
3b6b7e19 RM |
541 | min_size = alloc_sizes & -alloc_sizes; |
542 | if (min_size < PAGE_SIZE) { | |
543 | min_size = PAGE_SIZE; | |
544 | alloc_sizes |= PAGE_SIZE; | |
545 | } else { | |
546 | size = ALIGN(size, min_size); | |
547 | } | |
00085f1e | 548 | if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES) |
3b6b7e19 RM |
549 | alloc_sizes = min_size; |
550 | ||
551 | count = PAGE_ALIGN(size) >> PAGE_SHIFT; | |
552 | pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp); | |
0db2e5d1 RM |
553 | if (!pages) |
554 | return NULL; | |
555 | ||
842fe519 RM |
556 | size = iova_align(iovad, size); |
557 | iova = iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev); | |
0db2e5d1 RM |
558 | if (!iova) |
559 | goto out_free_pages; | |
560 | ||
0db2e5d1 RM |
561 | if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL)) |
562 | goto out_free_iova; | |
563 | ||
564 | if (!(prot & IOMMU_CACHE)) { | |
565 | struct sg_mapping_iter miter; | |
566 | /* | |
567 | * The CPU-centric flushing implied by SG_MITER_TO_SG isn't | |
568 | * sufficient here, so skip it by using the "wrong" direction. | |
569 | */ | |
570 | sg_miter_start(&miter, sgt.sgl, sgt.orig_nents, SG_MITER_FROM_SG); | |
571 | while (sg_miter_next(&miter)) | |
572 | flush_page(dev, miter.addr, page_to_phys(miter.page)); | |
573 | sg_miter_stop(&miter); | |
574 | } | |
575 | ||
842fe519 | 576 | if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot) |
0db2e5d1 RM |
577 | < size) |
578 | goto out_free_sg; | |
579 | ||
842fe519 | 580 | *handle = iova; |
0db2e5d1 RM |
581 | sg_free_table(&sgt); |
582 | return pages; | |
583 | ||
584 | out_free_sg: | |
585 | sg_free_table(&sgt); | |
586 | out_free_iova: | |
842fe519 | 587 | iommu_dma_free_iova(cookie, iova, size); |
0db2e5d1 RM |
588 | out_free_pages: |
589 | __iommu_dma_free_pages(pages, count); | |
590 | return NULL; | |
591 | } | |
592 | ||
593 | /** | |
594 | * iommu_dma_mmap - Map a buffer into provided user VMA | |
595 | * @pages: Array representing buffer from iommu_dma_alloc() | |
596 | * @size: Size of buffer in bytes | |
597 | * @vma: VMA describing requested userspace mapping | |
598 | * | |
599 | * Maps the pages of the buffer in @pages into @vma. The caller is responsible | |
600 | * for verifying the correct size and protection of @vma beforehand. | |
601 | */ | |
602 | ||
603 | int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma) | |
604 | { | |
605 | unsigned long uaddr = vma->vm_start; | |
606 | unsigned int i, count = PAGE_ALIGN(size) >> PAGE_SHIFT; | |
607 | int ret = -ENXIO; | |
608 | ||
609 | for (i = vma->vm_pgoff; i < count && uaddr < vma->vm_end; i++) { | |
610 | ret = vm_insert_page(vma, uaddr, pages[i]); | |
611 | if (ret) | |
612 | break; | |
613 | uaddr += PAGE_SIZE; | |
614 | } | |
615 | return ret; | |
616 | } | |
617 | ||
51f8cc9e RM |
618 | static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys, |
619 | size_t size, int prot) | |
0db2e5d1 | 620 | { |
0db2e5d1 | 621 | struct iommu_domain *domain = iommu_get_domain_for_dev(dev); |
842fe519 RM |
622 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
623 | struct iova_domain *iovad = &cookie->iovad; | |
0db2e5d1 | 624 | size_t iova_off = iova_offset(iovad, phys); |
842fe519 | 625 | dma_addr_t iova; |
0db2e5d1 | 626 | |
842fe519 RM |
627 | size = iova_align(iovad, size + iova_off); |
628 | iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev); | |
0db2e5d1 RM |
629 | if (!iova) |
630 | return DMA_ERROR_CODE; | |
631 | ||
842fe519 RM |
632 | if (iommu_map(domain, iova, phys - iova_off, size, prot)) { |
633 | iommu_dma_free_iova(cookie, iova, size); | |
0db2e5d1 RM |
634 | return DMA_ERROR_CODE; |
635 | } | |
842fe519 | 636 | return iova + iova_off; |
0db2e5d1 RM |
637 | } |
638 | ||
51f8cc9e RM |
639 | dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, |
640 | unsigned long offset, size_t size, int prot) | |
641 | { | |
642 | return __iommu_dma_map(dev, page_to_phys(page) + offset, size, prot); | |
643 | } | |
644 | ||
0db2e5d1 | 645 | void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size, |
00085f1e | 646 | enum dma_data_direction dir, unsigned long attrs) |
0db2e5d1 | 647 | { |
842fe519 | 648 | __iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle, size); |
0db2e5d1 RM |
649 | } |
650 | ||
651 | /* | |
652 | * Prepare a successfully-mapped scatterlist to give back to the caller. | |
809eac54 RM |
653 | * |
654 | * At this point the segments are already laid out by iommu_dma_map_sg() to | |
655 | * avoid individually crossing any boundaries, so we merely need to check a | |
656 | * segment's start address to avoid concatenating across one. | |
0db2e5d1 RM |
657 | */ |
658 | static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents, | |
659 | dma_addr_t dma_addr) | |
660 | { | |
809eac54 RM |
661 | struct scatterlist *s, *cur = sg; |
662 | unsigned long seg_mask = dma_get_seg_boundary(dev); | |
663 | unsigned int cur_len = 0, max_len = dma_get_max_seg_size(dev); | |
664 | int i, count = 0; | |
0db2e5d1 RM |
665 | |
666 | for_each_sg(sg, s, nents, i) { | |
809eac54 RM |
667 | /* Restore this segment's original unaligned fields first */ |
668 | unsigned int s_iova_off = sg_dma_address(s); | |
0db2e5d1 | 669 | unsigned int s_length = sg_dma_len(s); |
809eac54 | 670 | unsigned int s_iova_len = s->length; |
0db2e5d1 | 671 | |
809eac54 | 672 | s->offset += s_iova_off; |
0db2e5d1 | 673 | s->length = s_length; |
809eac54 RM |
674 | sg_dma_address(s) = DMA_ERROR_CODE; |
675 | sg_dma_len(s) = 0; | |
676 | ||
677 | /* | |
678 | * Now fill in the real DMA data. If... | |
679 | * - there is a valid output segment to append to | |
680 | * - and this segment starts on an IOVA page boundary | |
681 | * - but doesn't fall at a segment boundary | |
682 | * - and wouldn't make the resulting output segment too long | |
683 | */ | |
684 | if (cur_len && !s_iova_off && (dma_addr & seg_mask) && | |
685 | (cur_len + s_length <= max_len)) { | |
686 | /* ...then concatenate it with the previous one */ | |
687 | cur_len += s_length; | |
688 | } else { | |
689 | /* Otherwise start the next output segment */ | |
690 | if (i > 0) | |
691 | cur = sg_next(cur); | |
692 | cur_len = s_length; | |
693 | count++; | |
694 | ||
695 | sg_dma_address(cur) = dma_addr + s_iova_off; | |
696 | } | |
697 | ||
698 | sg_dma_len(cur) = cur_len; | |
699 | dma_addr += s_iova_len; | |
700 | ||
701 | if (s_length + s_iova_off < s_iova_len) | |
702 | cur_len = 0; | |
0db2e5d1 | 703 | } |
809eac54 | 704 | return count; |
0db2e5d1 RM |
705 | } |
706 | ||
707 | /* | |
708 | * If mapping failed, then just restore the original list, | |
709 | * but making sure the DMA fields are invalidated. | |
710 | */ | |
711 | static void __invalidate_sg(struct scatterlist *sg, int nents) | |
712 | { | |
713 | struct scatterlist *s; | |
714 | int i; | |
715 | ||
716 | for_each_sg(sg, s, nents, i) { | |
717 | if (sg_dma_address(s) != DMA_ERROR_CODE) | |
07b48ac4 | 718 | s->offset += sg_dma_address(s); |
0db2e5d1 RM |
719 | if (sg_dma_len(s)) |
720 | s->length = sg_dma_len(s); | |
721 | sg_dma_address(s) = DMA_ERROR_CODE; | |
722 | sg_dma_len(s) = 0; | |
723 | } | |
724 | } | |
725 | ||
726 | /* | |
727 | * The DMA API client is passing in a scatterlist which could describe | |
728 | * any old buffer layout, but the IOMMU API requires everything to be | |
729 | * aligned to IOMMU pages. Hence the need for this complicated bit of | |
730 | * impedance-matching, to be able to hand off a suitably-aligned list, | |
731 | * but still preserve the original offsets and sizes for the caller. | |
732 | */ | |
733 | int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, | |
734 | int nents, int prot) | |
735 | { | |
736 | struct iommu_domain *domain = iommu_get_domain_for_dev(dev); | |
842fe519 RM |
737 | struct iommu_dma_cookie *cookie = domain->iova_cookie; |
738 | struct iova_domain *iovad = &cookie->iovad; | |
0db2e5d1 | 739 | struct scatterlist *s, *prev = NULL; |
842fe519 | 740 | dma_addr_t iova; |
0db2e5d1 | 741 | size_t iova_len = 0; |
809eac54 | 742 | unsigned long mask = dma_get_seg_boundary(dev); |
0db2e5d1 RM |
743 | int i; |
744 | ||
745 | /* | |
746 | * Work out how much IOVA space we need, and align the segments to | |
747 | * IOVA granules for the IOMMU driver to handle. With some clever | |
748 | * trickery we can modify the list in-place, but reversibly, by | |
809eac54 | 749 | * stashing the unaligned parts in the as-yet-unused DMA fields. |
0db2e5d1 RM |
750 | */ |
751 | for_each_sg(sg, s, nents, i) { | |
809eac54 | 752 | size_t s_iova_off = iova_offset(iovad, s->offset); |
0db2e5d1 | 753 | size_t s_length = s->length; |
809eac54 | 754 | size_t pad_len = (mask - iova_len + 1) & mask; |
0db2e5d1 | 755 | |
809eac54 | 756 | sg_dma_address(s) = s_iova_off; |
0db2e5d1 | 757 | sg_dma_len(s) = s_length; |
809eac54 RM |
758 | s->offset -= s_iova_off; |
759 | s_length = iova_align(iovad, s_length + s_iova_off); | |
0db2e5d1 RM |
760 | s->length = s_length; |
761 | ||
762 | /* | |
809eac54 RM |
763 | * Due to the alignment of our single IOVA allocation, we can |
764 | * depend on these assumptions about the segment boundary mask: | |
765 | * - If mask size >= IOVA size, then the IOVA range cannot | |
766 | * possibly fall across a boundary, so we don't care. | |
767 | * - If mask size < IOVA size, then the IOVA range must start | |
768 | * exactly on a boundary, therefore we can lay things out | |
769 | * based purely on segment lengths without needing to know | |
770 | * the actual addresses beforehand. | |
771 | * - The mask must be a power of 2, so pad_len == 0 if | |
772 | * iova_len == 0, thus we cannot dereference prev the first | |
773 | * time through here (i.e. before it has a meaningful value). | |
0db2e5d1 | 774 | */ |
809eac54 | 775 | if (pad_len && pad_len < s_length - 1) { |
0db2e5d1 RM |
776 | prev->length += pad_len; |
777 | iova_len += pad_len; | |
778 | } | |
779 | ||
780 | iova_len += s_length; | |
781 | prev = s; | |
782 | } | |
783 | ||
842fe519 | 784 | iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev); |
0db2e5d1 RM |
785 | if (!iova) |
786 | goto out_restore_sg; | |
787 | ||
788 | /* | |
789 | * We'll leave any physical concatenation to the IOMMU driver's | |
790 | * implementation - it knows better than we do. | |
791 | */ | |
842fe519 | 792 | if (iommu_map_sg(domain, iova, sg, nents, prot) < iova_len) |
0db2e5d1 RM |
793 | goto out_free_iova; |
794 | ||
842fe519 | 795 | return __finalise_sg(dev, sg, nents, iova); |
0db2e5d1 RM |
796 | |
797 | out_free_iova: | |
842fe519 | 798 | iommu_dma_free_iova(cookie, iova, iova_len); |
0db2e5d1 RM |
799 | out_restore_sg: |
800 | __invalidate_sg(sg, nents); | |
801 | return 0; | |
802 | } | |
803 | ||
804 | void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, | |
00085f1e | 805 | enum dma_data_direction dir, unsigned long attrs) |
0db2e5d1 | 806 | { |
842fe519 RM |
807 | dma_addr_t start, end; |
808 | struct scatterlist *tmp; | |
809 | int i; | |
0db2e5d1 RM |
810 | /* |
811 | * The scatterlist segments are mapped into a single | |
812 | * contiguous IOVA allocation, so this is incredibly easy. | |
813 | */ | |
842fe519 RM |
814 | start = sg_dma_address(sg); |
815 | for_each_sg(sg_next(sg), tmp, nents - 1, i) { | |
816 | if (sg_dma_len(tmp) == 0) | |
817 | break; | |
818 | sg = tmp; | |
819 | } | |
820 | end = sg_dma_address(sg) + sg_dma_len(sg); | |
821 | __iommu_dma_unmap(iommu_get_domain_for_dev(dev), start, end - start); | |
0db2e5d1 RM |
822 | } |
823 | ||
51f8cc9e RM |
824 | dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys, |
825 | size_t size, enum dma_data_direction dir, unsigned long attrs) | |
826 | { | |
827 | return __iommu_dma_map(dev, phys, size, | |
737c85ca | 828 | dma_info_to_prot(dir, false, attrs) | IOMMU_MMIO); |
51f8cc9e RM |
829 | } |
830 | ||
831 | void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle, | |
832 | size_t size, enum dma_data_direction dir, unsigned long attrs) | |
833 | { | |
842fe519 | 834 | __iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle, size); |
51f8cc9e RM |
835 | } |
836 | ||
0db2e5d1 RM |
837 | int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) |
838 | { | |
839 | return dma_addr == DMA_ERROR_CODE; | |
840 | } | |
44bb7e24 RM |
841 | |
842 | static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev, | |
843 | phys_addr_t msi_addr, struct iommu_domain *domain) | |
844 | { | |
845 | struct iommu_dma_cookie *cookie = domain->iova_cookie; | |
846 | struct iommu_dma_msi_page *msi_page; | |
842fe519 | 847 | dma_addr_t iova; |
44bb7e24 | 848 | int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO; |
fdbe574e | 849 | size_t size = cookie_msi_granule(cookie); |
44bb7e24 | 850 | |
fdbe574e | 851 | msi_addr &= ~(phys_addr_t)(size - 1); |
44bb7e24 RM |
852 | list_for_each_entry(msi_page, &cookie->msi_page_list, list) |
853 | if (msi_page->phys == msi_addr) | |
854 | return msi_page; | |
855 | ||
856 | msi_page = kzalloc(sizeof(*msi_page), GFP_ATOMIC); | |
857 | if (!msi_page) | |
858 | return NULL; | |
859 | ||
a44e6657 RM |
860 | iova = __iommu_dma_map(dev, msi_addr, size, prot); |
861 | if (iommu_dma_mapping_error(dev, iova)) | |
862 | goto out_free_page; | |
44bb7e24 RM |
863 | |
864 | INIT_LIST_HEAD(&msi_page->list); | |
a44e6657 RM |
865 | msi_page->phys = msi_addr; |
866 | msi_page->iova = iova; | |
44bb7e24 RM |
867 | list_add(&msi_page->list, &cookie->msi_page_list); |
868 | return msi_page; | |
869 | ||
44bb7e24 RM |
870 | out_free_page: |
871 | kfree(msi_page); | |
872 | return NULL; | |
873 | } | |
874 | ||
875 | void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg) | |
876 | { | |
877 | struct device *dev = msi_desc_to_dev(irq_get_msi_desc(irq)); | |
878 | struct iommu_domain *domain = iommu_get_domain_for_dev(dev); | |
879 | struct iommu_dma_cookie *cookie; | |
880 | struct iommu_dma_msi_page *msi_page; | |
881 | phys_addr_t msi_addr = (u64)msg->address_hi << 32 | msg->address_lo; | |
882 | unsigned long flags; | |
883 | ||
884 | if (!domain || !domain->iova_cookie) | |
885 | return; | |
886 | ||
887 | cookie = domain->iova_cookie; | |
888 | ||
889 | /* | |
890 | * We disable IRQs to rule out a possible inversion against | |
891 | * irq_desc_lock if, say, someone tries to retarget the affinity | |
892 | * of an MSI from within an IPI handler. | |
893 | */ | |
894 | spin_lock_irqsave(&cookie->msi_lock, flags); | |
895 | msi_page = iommu_dma_get_msi_page(dev, msi_addr, domain); | |
896 | spin_unlock_irqrestore(&cookie->msi_lock, flags); | |
897 | ||
898 | if (WARN_ON(!msi_page)) { | |
899 | /* | |
900 | * We're called from a void callback, so the best we can do is | |
901 | * 'fail' by filling the message with obviously bogus values. | |
902 | * Since we got this far due to an IOMMU being present, it's | |
903 | * not like the existing address would have worked anyway... | |
904 | */ | |
905 | msg->address_hi = ~0U; | |
906 | msg->address_lo = ~0U; | |
907 | msg->data = ~0U; | |
908 | } else { | |
909 | msg->address_hi = upper_32_bits(msi_page->iova); | |
fdbe574e | 910 | msg->address_lo &= cookie_msi_granule(cookie) - 1; |
44bb7e24 RM |
911 | msg->address_lo += lower_32_bits(msi_page->iova); |
912 | } | |
913 | } |