]>
Commit | Line | Data |
---|---|---|
b097186f KRW |
1 | /* |
2 | * Copyright 2010 | |
3 | * by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | |
4 | * | |
5 | * This code provides a IOMMU for Xen PV guests with PCI passthrough. | |
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 v2.0 as published by | |
9 | * 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 | * PV guests under Xen are running in an non-contiguous memory architecture. | |
17 | * | |
18 | * When PCI pass-through is utilized, this necessitates an IOMMU for | |
19 | * translating bus (DMA) to virtual and vice-versa and also providing a | |
20 | * mechanism to have contiguous pages for device drivers operations (say DMA | |
21 | * operations). | |
22 | * | |
23 | * Specifically, under Xen the Linux idea of pages is an illusion. It | |
24 | * assumes that pages start at zero and go up to the available memory. To | |
25 | * help with that, the Linux Xen MMU provides a lookup mechanism to | |
26 | * translate the page frame numbers (PFN) to machine frame numbers (MFN) | |
27 | * and vice-versa. The MFN are the "real" frame numbers. Furthermore | |
28 | * memory is not contiguous. Xen hypervisor stitches memory for guests | |
29 | * from different pools, which means there is no guarantee that PFN==MFN | |
30 | * and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are | |
31 | * allocated in descending order (high to low), meaning the guest might | |
32 | * never get any MFN's under the 4GB mark. | |
33 | * | |
34 | */ | |
35 | ||
36 | #include <linux/bootmem.h> | |
37 | #include <linux/dma-mapping.h> | |
63c9744b | 38 | #include <linux/export.h> |
b097186f KRW |
39 | #include <xen/swiotlb-xen.h> |
40 | #include <xen/page.h> | |
41 | #include <xen/xen-ops.h> | |
f4b2f07b | 42 | #include <xen/hvc-console.h> |
b097186f KRW |
43 | /* |
44 | * Used to do a quick range check in swiotlb_tbl_unmap_single and | |
45 | * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this | |
46 | * API. | |
47 | */ | |
48 | ||
49 | static char *xen_io_tlb_start, *xen_io_tlb_end; | |
50 | static unsigned long xen_io_tlb_nslabs; | |
51 | /* | |
52 | * Quick lookup value of the bus address of the IOTLB. | |
53 | */ | |
54 | ||
55 | u64 start_dma_addr; | |
56 | ||
57 | static dma_addr_t xen_phys_to_bus(phys_addr_t paddr) | |
58 | { | |
6eab04a8 | 59 | return phys_to_machine(XPADDR(paddr)).maddr; |
b097186f KRW |
60 | } |
61 | ||
62 | static phys_addr_t xen_bus_to_phys(dma_addr_t baddr) | |
63 | { | |
64 | return machine_to_phys(XMADDR(baddr)).paddr; | |
65 | } | |
66 | ||
67 | static dma_addr_t xen_virt_to_bus(void *address) | |
68 | { | |
69 | return xen_phys_to_bus(virt_to_phys(address)); | |
70 | } | |
71 | ||
72 | static int check_pages_physically_contiguous(unsigned long pfn, | |
73 | unsigned int offset, | |
74 | size_t length) | |
75 | { | |
76 | unsigned long next_mfn; | |
77 | int i; | |
78 | int nr_pages; | |
79 | ||
80 | next_mfn = pfn_to_mfn(pfn); | |
81 | nr_pages = (offset + length + PAGE_SIZE-1) >> PAGE_SHIFT; | |
82 | ||
83 | for (i = 1; i < nr_pages; i++) { | |
84 | if (pfn_to_mfn(++pfn) != ++next_mfn) | |
85 | return 0; | |
86 | } | |
87 | return 1; | |
88 | } | |
89 | ||
90 | static int range_straddles_page_boundary(phys_addr_t p, size_t size) | |
91 | { | |
92 | unsigned long pfn = PFN_DOWN(p); | |
93 | unsigned int offset = p & ~PAGE_MASK; | |
94 | ||
95 | if (offset + size <= PAGE_SIZE) | |
96 | return 0; | |
97 | if (check_pages_physically_contiguous(pfn, offset, size)) | |
98 | return 0; | |
99 | return 1; | |
100 | } | |
101 | ||
102 | static int is_xen_swiotlb_buffer(dma_addr_t dma_addr) | |
103 | { | |
104 | unsigned long mfn = PFN_DOWN(dma_addr); | |
105 | unsigned long pfn = mfn_to_local_pfn(mfn); | |
106 | phys_addr_t paddr; | |
107 | ||
108 | /* If the address is outside our domain, it CAN | |
109 | * have the same virtual address as another address | |
110 | * in our domain. Therefore _only_ check address within our domain. | |
111 | */ | |
112 | if (pfn_valid(pfn)) { | |
113 | paddr = PFN_PHYS(pfn); | |
114 | return paddr >= virt_to_phys(xen_io_tlb_start) && | |
115 | paddr < virt_to_phys(xen_io_tlb_end); | |
116 | } | |
117 | return 0; | |
118 | } | |
119 | ||
120 | static int max_dma_bits = 32; | |
121 | ||
122 | static int | |
123 | xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) | |
124 | { | |
125 | int i, rc; | |
126 | int dma_bits; | |
127 | ||
128 | dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; | |
129 | ||
130 | i = 0; | |
131 | do { | |
132 | int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE); | |
133 | ||
134 | do { | |
135 | rc = xen_create_contiguous_region( | |
136 | (unsigned long)buf + (i << IO_TLB_SHIFT), | |
137 | get_order(slabs << IO_TLB_SHIFT), | |
138 | dma_bits); | |
139 | } while (rc && dma_bits++ < max_dma_bits); | |
140 | if (rc) | |
141 | return rc; | |
142 | ||
143 | i += slabs; | |
144 | } while (i < nslabs); | |
145 | return 0; | |
146 | } | |
147 | ||
148 | void __init xen_swiotlb_init(int verbose) | |
149 | { | |
150 | unsigned long bytes; | |
f4b2f07b | 151 | int rc = -ENOMEM; |
5f98ecdb | 152 | unsigned long nr_tbl; |
f4b2f07b KRW |
153 | char *m = NULL; |
154 | unsigned int repeat = 3; | |
5f98ecdb | 155 | |
f21ffe9f | 156 | nr_tbl = swiotlb_nr_tbl(); |
5f98ecdb FT |
157 | if (nr_tbl) |
158 | xen_io_tlb_nslabs = nr_tbl; | |
159 | else { | |
160 | xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT); | |
161 | xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE); | |
162 | } | |
f4b2f07b | 163 | retry: |
b097186f KRW |
164 | bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT; |
165 | ||
166 | /* | |
167 | * Get IO TLB memory from any location. | |
168 | */ | |
63a74175 | 169 | xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes)); |
f4b2f07b KRW |
170 | if (!xen_io_tlb_start) { |
171 | m = "Cannot allocate Xen-SWIOTLB buffer!\n"; | |
172 | goto error; | |
173 | } | |
b097186f KRW |
174 | xen_io_tlb_end = xen_io_tlb_start + bytes; |
175 | /* | |
176 | * And replace that memory with pages under 4GB. | |
177 | */ | |
178 | rc = xen_swiotlb_fixup(xen_io_tlb_start, | |
179 | bytes, | |
180 | xen_io_tlb_nslabs); | |
f4b2f07b | 181 | if (rc) { |
63a74175 | 182 | free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes)); |
f4b2f07b KRW |
183 | m = "Failed to get contiguous memory for DMA from Xen!\n"\ |
184 | "You either: don't have the permissions, do not have"\ | |
185 | " enough free memory under 4GB, or the hypervisor memory"\ | |
186 | "is too fragmented!"; | |
b097186f | 187 | goto error; |
f4b2f07b | 188 | } |
b097186f KRW |
189 | start_dma_addr = xen_virt_to_bus(xen_io_tlb_start); |
190 | swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose); | |
191 | ||
192 | return; | |
193 | error: | |
f4b2f07b KRW |
194 | if (repeat--) { |
195 | xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */ | |
196 | (xen_io_tlb_nslabs >> 1)); | |
197 | printk(KERN_INFO "Xen-SWIOTLB: Lowering to %luMB\n", | |
198 | (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20); | |
199 | goto retry; | |
200 | } | |
61ca7983 RD |
201 | xen_raw_printk("%s (rc:%d)", m, rc); |
202 | panic("%s (rc:%d)", m, rc); | |
b097186f KRW |
203 | } |
204 | ||
205 | void * | |
206 | xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, | |
207 | dma_addr_t *dma_handle, gfp_t flags) | |
208 | { | |
209 | void *ret; | |
210 | int order = get_order(size); | |
211 | u64 dma_mask = DMA_BIT_MASK(32); | |
212 | unsigned long vstart; | |
6810df88 KRW |
213 | phys_addr_t phys; |
214 | dma_addr_t dev_addr; | |
b097186f KRW |
215 | |
216 | /* | |
217 | * Ignore region specifiers - the kernel's ideas of | |
218 | * pseudo-phys memory layout has nothing to do with the | |
219 | * machine physical layout. We can't allocate highmem | |
220 | * because we can't return a pointer to it. | |
221 | */ | |
222 | flags &= ~(__GFP_DMA | __GFP_HIGHMEM); | |
223 | ||
224 | if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) | |
225 | return ret; | |
226 | ||
227 | vstart = __get_free_pages(flags, order); | |
228 | ret = (void *)vstart; | |
229 | ||
6810df88 KRW |
230 | if (!ret) |
231 | return ret; | |
232 | ||
b097186f | 233 | if (hwdev && hwdev->coherent_dma_mask) |
6810df88 | 234 | dma_mask = hwdev->coherent_dma_mask; |
b097186f | 235 | |
6810df88 KRW |
236 | phys = virt_to_phys(ret); |
237 | dev_addr = xen_phys_to_bus(phys); | |
238 | if (((dev_addr + size - 1 <= dma_mask)) && | |
239 | !range_straddles_page_boundary(phys, size)) | |
240 | *dma_handle = dev_addr; | |
241 | else { | |
b097186f KRW |
242 | if (xen_create_contiguous_region(vstart, order, |
243 | fls64(dma_mask)) != 0) { | |
244 | free_pages(vstart, order); | |
245 | return NULL; | |
246 | } | |
b097186f KRW |
247 | *dma_handle = virt_to_machine(ret).maddr; |
248 | } | |
6810df88 | 249 | memset(ret, 0, size); |
b097186f KRW |
250 | return ret; |
251 | } | |
252 | EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent); | |
253 | ||
254 | void | |
255 | xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, | |
256 | dma_addr_t dev_addr) | |
257 | { | |
258 | int order = get_order(size); | |
6810df88 KRW |
259 | phys_addr_t phys; |
260 | u64 dma_mask = DMA_BIT_MASK(32); | |
b097186f KRW |
261 | |
262 | if (dma_release_from_coherent(hwdev, order, vaddr)) | |
263 | return; | |
264 | ||
6810df88 KRW |
265 | if (hwdev && hwdev->coherent_dma_mask) |
266 | dma_mask = hwdev->coherent_dma_mask; | |
267 | ||
268 | phys = virt_to_phys(vaddr); | |
269 | ||
270 | if (((dev_addr + size - 1 > dma_mask)) || | |
271 | range_straddles_page_boundary(phys, size)) | |
272 | xen_destroy_contiguous_region((unsigned long)vaddr, order); | |
273 | ||
b097186f KRW |
274 | free_pages((unsigned long)vaddr, order); |
275 | } | |
276 | EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); | |
277 | ||
278 | ||
279 | /* | |
280 | * Map a single buffer of the indicated size for DMA in streaming mode. The | |
281 | * physical address to use is returned. | |
282 | * | |
283 | * Once the device is given the dma address, the device owns this memory until | |
284 | * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed. | |
285 | */ | |
286 | dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, | |
287 | unsigned long offset, size_t size, | |
288 | enum dma_data_direction dir, | |
289 | struct dma_attrs *attrs) | |
290 | { | |
291 | phys_addr_t phys = page_to_phys(page) + offset; | |
292 | dma_addr_t dev_addr = xen_phys_to_bus(phys); | |
293 | void *map; | |
294 | ||
295 | BUG_ON(dir == DMA_NONE); | |
296 | /* | |
297 | * If the address happens to be in the device's DMA window, | |
298 | * we can safely return the device addr and not worry about bounce | |
299 | * buffering it. | |
300 | */ | |
301 | if (dma_capable(dev, dev_addr, size) && | |
302 | !range_straddles_page_boundary(phys, size) && !swiotlb_force) | |
303 | return dev_addr; | |
304 | ||
305 | /* | |
306 | * Oh well, have to allocate and map a bounce buffer. | |
307 | */ | |
308 | map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir); | |
309 | if (!map) | |
310 | return DMA_ERROR_CODE; | |
311 | ||
312 | dev_addr = xen_virt_to_bus(map); | |
313 | ||
314 | /* | |
315 | * Ensure that the address returned is DMA'ble | |
316 | */ | |
ab2a47bd KRW |
317 | if (!dma_capable(dev, dev_addr, size)) { |
318 | swiotlb_tbl_unmap_single(dev, map, size, dir); | |
319 | dev_addr = 0; | |
320 | } | |
b097186f KRW |
321 | return dev_addr; |
322 | } | |
323 | EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); | |
324 | ||
325 | /* | |
326 | * Unmap a single streaming mode DMA translation. The dma_addr and size must | |
327 | * match what was provided for in a previous xen_swiotlb_map_page call. All | |
328 | * other usages are undefined. | |
329 | * | |
330 | * After this call, reads by the cpu to the buffer are guaranteed to see | |
331 | * whatever the device wrote there. | |
332 | */ | |
333 | static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, | |
334 | size_t size, enum dma_data_direction dir) | |
335 | { | |
336 | phys_addr_t paddr = xen_bus_to_phys(dev_addr); | |
337 | ||
338 | BUG_ON(dir == DMA_NONE); | |
339 | ||
340 | /* NOTE: We use dev_addr here, not paddr! */ | |
341 | if (is_xen_swiotlb_buffer(dev_addr)) { | |
342 | swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir); | |
343 | return; | |
344 | } | |
345 | ||
346 | if (dir != DMA_FROM_DEVICE) | |
347 | return; | |
348 | ||
349 | /* | |
350 | * phys_to_virt doesn't work with hihgmem page but we could | |
351 | * call dma_mark_clean() with hihgmem page here. However, we | |
352 | * are fine since dma_mark_clean() is null on POWERPC. We can | |
353 | * make dma_mark_clean() take a physical address if necessary. | |
354 | */ | |
355 | dma_mark_clean(phys_to_virt(paddr), size); | |
356 | } | |
357 | ||
358 | void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, | |
359 | size_t size, enum dma_data_direction dir, | |
360 | struct dma_attrs *attrs) | |
361 | { | |
362 | xen_unmap_single(hwdev, dev_addr, size, dir); | |
363 | } | |
364 | EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page); | |
365 | ||
366 | /* | |
367 | * Make physical memory consistent for a single streaming mode DMA translation | |
368 | * after a transfer. | |
369 | * | |
370 | * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer | |
371 | * using the cpu, yet do not wish to teardown the dma mapping, you must | |
372 | * call this function before doing so. At the next point you give the dma | |
373 | * address back to the card, you must first perform a | |
374 | * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer | |
375 | */ | |
376 | static void | |
377 | xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, | |
378 | size_t size, enum dma_data_direction dir, | |
379 | enum dma_sync_target target) | |
380 | { | |
381 | phys_addr_t paddr = xen_bus_to_phys(dev_addr); | |
382 | ||
383 | BUG_ON(dir == DMA_NONE); | |
384 | ||
385 | /* NOTE: We use dev_addr here, not paddr! */ | |
386 | if (is_xen_swiotlb_buffer(dev_addr)) { | |
387 | swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir, | |
388 | target); | |
389 | return; | |
390 | } | |
391 | ||
392 | if (dir != DMA_FROM_DEVICE) | |
393 | return; | |
394 | ||
395 | dma_mark_clean(phys_to_virt(paddr), size); | |
396 | } | |
397 | ||
398 | void | |
399 | xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, | |
400 | size_t size, enum dma_data_direction dir) | |
401 | { | |
402 | xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); | |
403 | } | |
404 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_cpu); | |
405 | ||
406 | void | |
407 | xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, | |
408 | size_t size, enum dma_data_direction dir) | |
409 | { | |
410 | xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); | |
411 | } | |
412 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device); | |
413 | ||
414 | /* | |
415 | * Map a set of buffers described by scatterlist in streaming mode for DMA. | |
416 | * This is the scatter-gather version of the above xen_swiotlb_map_page | |
417 | * interface. Here the scatter gather list elements are each tagged with the | |
418 | * appropriate dma address and length. They are obtained via | |
419 | * sg_dma_{address,length}(SG). | |
420 | * | |
421 | * NOTE: An implementation may be able to use a smaller number of | |
422 | * DMA address/length pairs than there are SG table elements. | |
423 | * (for example via virtual mapping capabilities) | |
424 | * The routine returns the number of addr/length pairs actually | |
425 | * used, at most nents. | |
426 | * | |
427 | * Device ownership issues as mentioned above for xen_swiotlb_map_page are the | |
428 | * same here. | |
429 | */ | |
430 | int | |
431 | xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, | |
432 | int nelems, enum dma_data_direction dir, | |
433 | struct dma_attrs *attrs) | |
434 | { | |
435 | struct scatterlist *sg; | |
436 | int i; | |
437 | ||
438 | BUG_ON(dir == DMA_NONE); | |
439 | ||
440 | for_each_sg(sgl, sg, nelems, i) { | |
441 | phys_addr_t paddr = sg_phys(sg); | |
442 | dma_addr_t dev_addr = xen_phys_to_bus(paddr); | |
443 | ||
444 | if (swiotlb_force || | |
445 | !dma_capable(hwdev, dev_addr, sg->length) || | |
446 | range_straddles_page_boundary(paddr, sg->length)) { | |
447 | void *map = swiotlb_tbl_map_single(hwdev, | |
448 | start_dma_addr, | |
449 | sg_phys(sg), | |
450 | sg->length, dir); | |
451 | if (!map) { | |
452 | /* Don't panic here, we expect map_sg users | |
453 | to do proper error handling. */ | |
454 | xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, | |
455 | attrs); | |
456 | sgl[0].dma_length = 0; | |
457 | return DMA_ERROR_CODE; | |
458 | } | |
459 | sg->dma_address = xen_virt_to_bus(map); | |
460 | } else | |
461 | sg->dma_address = dev_addr; | |
462 | sg->dma_length = sg->length; | |
463 | } | |
464 | return nelems; | |
465 | } | |
466 | EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs); | |
467 | ||
468 | int | |
469 | xen_swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, | |
470 | enum dma_data_direction dir) | |
471 | { | |
472 | return xen_swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL); | |
473 | } | |
474 | EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg); | |
475 | ||
476 | /* | |
477 | * Unmap a set of streaming mode DMA translations. Again, cpu read rules | |
478 | * concerning calls here are the same as for swiotlb_unmap_page() above. | |
479 | */ | |
480 | void | |
481 | xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, | |
482 | int nelems, enum dma_data_direction dir, | |
483 | struct dma_attrs *attrs) | |
484 | { | |
485 | struct scatterlist *sg; | |
486 | int i; | |
487 | ||
488 | BUG_ON(dir == DMA_NONE); | |
489 | ||
490 | for_each_sg(sgl, sg, nelems, i) | |
491 | xen_unmap_single(hwdev, sg->dma_address, sg->dma_length, dir); | |
492 | ||
493 | } | |
494 | EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs); | |
495 | ||
496 | void | |
497 | xen_swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems, | |
498 | enum dma_data_direction dir) | |
499 | { | |
500 | return xen_swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL); | |
501 | } | |
502 | EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg); | |
503 | ||
504 | /* | |
505 | * Make physical memory consistent for a set of streaming mode DMA translations | |
506 | * after a transfer. | |
507 | * | |
508 | * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules | |
509 | * and usage. | |
510 | */ | |
511 | static void | |
512 | xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, | |
513 | int nelems, enum dma_data_direction dir, | |
514 | enum dma_sync_target target) | |
515 | { | |
516 | struct scatterlist *sg; | |
517 | int i; | |
518 | ||
519 | for_each_sg(sgl, sg, nelems, i) | |
520 | xen_swiotlb_sync_single(hwdev, sg->dma_address, | |
521 | sg->dma_length, dir, target); | |
522 | } | |
523 | ||
524 | void | |
525 | xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, | |
526 | int nelems, enum dma_data_direction dir) | |
527 | { | |
528 | xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); | |
529 | } | |
530 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_cpu); | |
531 | ||
532 | void | |
533 | xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, | |
534 | int nelems, enum dma_data_direction dir) | |
535 | { | |
536 | xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); | |
537 | } | |
538 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device); | |
539 | ||
540 | int | |
541 | xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) | |
542 | { | |
543 | return !dma_addr; | |
544 | } | |
545 | EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error); | |
546 | ||
547 | /* | |
548 | * Return whether the given device DMA address mask can be supported | |
549 | * properly. For example, if your device can only drive the low 24-bits | |
550 | * during bus mastering, then you would pass 0x00ffffff as the mask to | |
551 | * this function. | |
552 | */ | |
553 | int | |
554 | xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) | |
555 | { | |
556 | return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask; | |
557 | } | |
558 | EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported); |