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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 | ||
b8b0f559 | 55 | static u64 start_dma_addr; |
b097186f KRW |
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 | } | |
1cef36a5 KRW |
147 | static unsigned long xen_set_nslabs(unsigned long nr_tbl) |
148 | { | |
149 | if (!nr_tbl) { | |
150 | xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT); | |
151 | xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE); | |
152 | } else | |
153 | xen_io_tlb_nslabs = nr_tbl; | |
b097186f | 154 | |
1cef36a5 KRW |
155 | return xen_io_tlb_nslabs << IO_TLB_SHIFT; |
156 | } | |
b097186f | 157 | |
5bab7864 KRW |
158 | enum xen_swiotlb_err { |
159 | XEN_SWIOTLB_UNKNOWN = 0, | |
160 | XEN_SWIOTLB_ENOMEM, | |
161 | XEN_SWIOTLB_EFIXUP | |
162 | }; | |
163 | ||
164 | static const char *xen_swiotlb_error(enum xen_swiotlb_err err) | |
165 | { | |
166 | switch (err) { | |
167 | case XEN_SWIOTLB_ENOMEM: | |
168 | return "Cannot allocate Xen-SWIOTLB buffer\n"; | |
169 | case XEN_SWIOTLB_EFIXUP: | |
170 | return "Failed to get contiguous memory for DMA from Xen!\n"\ | |
171 | "You either: don't have the permissions, do not have"\ | |
172 | " enough free memory under 4GB, or the hypervisor memory"\ | |
173 | " is too fragmented!"; | |
174 | default: | |
175 | break; | |
176 | } | |
177 | return ""; | |
178 | } | |
b8277600 | 179 | int __ref xen_swiotlb_init(int verbose, bool early) |
b097186f | 180 | { |
b8277600 | 181 | unsigned long bytes, order; |
f4b2f07b | 182 | int rc = -ENOMEM; |
5bab7864 | 183 | enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN; |
f4b2f07b | 184 | unsigned int repeat = 3; |
5f98ecdb | 185 | |
1cef36a5 | 186 | xen_io_tlb_nslabs = swiotlb_nr_tbl(); |
f4b2f07b | 187 | retry: |
1cef36a5 | 188 | bytes = xen_set_nslabs(xen_io_tlb_nslabs); |
b8277600 | 189 | order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT); |
b097186f KRW |
190 | /* |
191 | * Get IO TLB memory from any location. | |
192 | */ | |
b8277600 KRW |
193 | if (early) |
194 | xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes)); | |
195 | else { | |
196 | #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT)) | |
197 | #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) | |
198 | while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { | |
199 | xen_io_tlb_start = (void *)__get_free_pages(__GFP_NOWARN, order); | |
200 | if (xen_io_tlb_start) | |
201 | break; | |
202 | order--; | |
203 | } | |
204 | if (order != get_order(bytes)) { | |
205 | pr_warn("Warning: only able to allocate %ld MB " | |
206 | "for software IO TLB\n", (PAGE_SIZE << order) >> 20); | |
207 | xen_io_tlb_nslabs = SLABS_PER_PAGE << order; | |
208 | bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT; | |
209 | } | |
210 | } | |
f4b2f07b | 211 | if (!xen_io_tlb_start) { |
5bab7864 | 212 | m_ret = XEN_SWIOTLB_ENOMEM; |
f4b2f07b KRW |
213 | goto error; |
214 | } | |
b097186f KRW |
215 | xen_io_tlb_end = xen_io_tlb_start + bytes; |
216 | /* | |
217 | * And replace that memory with pages under 4GB. | |
218 | */ | |
219 | rc = xen_swiotlb_fixup(xen_io_tlb_start, | |
220 | bytes, | |
221 | xen_io_tlb_nslabs); | |
f4b2f07b | 222 | if (rc) { |
b8277600 KRW |
223 | if (early) |
224 | free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes)); | |
225 | else { | |
226 | free_pages((unsigned long)xen_io_tlb_start, order); | |
227 | xen_io_tlb_start = NULL; | |
228 | } | |
5bab7864 | 229 | m_ret = XEN_SWIOTLB_EFIXUP; |
b097186f | 230 | goto error; |
f4b2f07b | 231 | } |
b097186f | 232 | start_dma_addr = xen_virt_to_bus(xen_io_tlb_start); |
c468bdee | 233 | if (early) { |
b8277600 | 234 | swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose); |
c468bdee KRW |
235 | rc = 0; |
236 | } else | |
b8277600 KRW |
237 | rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs); |
238 | return rc; | |
b097186f | 239 | error: |
f4b2f07b KRW |
240 | if (repeat--) { |
241 | xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */ | |
242 | (xen_io_tlb_nslabs >> 1)); | |
243 | printk(KERN_INFO "Xen-SWIOTLB: Lowering to %luMB\n", | |
244 | (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20); | |
245 | goto retry; | |
246 | } | |
b8277600 KRW |
247 | pr_err("%s (rc:%d)", xen_swiotlb_error(m_ret), rc); |
248 | if (early) | |
249 | panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc); | |
250 | else | |
251 | free_pages((unsigned long)xen_io_tlb_start, order); | |
252 | return rc; | |
b097186f | 253 | } |
b097186f KRW |
254 | void * |
255 | xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, | |
baa676fc AP |
256 | dma_addr_t *dma_handle, gfp_t flags, |
257 | struct dma_attrs *attrs) | |
b097186f KRW |
258 | { |
259 | void *ret; | |
260 | int order = get_order(size); | |
261 | u64 dma_mask = DMA_BIT_MASK(32); | |
262 | unsigned long vstart; | |
6810df88 KRW |
263 | phys_addr_t phys; |
264 | dma_addr_t dev_addr; | |
b097186f KRW |
265 | |
266 | /* | |
267 | * Ignore region specifiers - the kernel's ideas of | |
268 | * pseudo-phys memory layout has nothing to do with the | |
269 | * machine physical layout. We can't allocate highmem | |
270 | * because we can't return a pointer to it. | |
271 | */ | |
272 | flags &= ~(__GFP_DMA | __GFP_HIGHMEM); | |
273 | ||
274 | if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) | |
275 | return ret; | |
276 | ||
277 | vstart = __get_free_pages(flags, order); | |
278 | ret = (void *)vstart; | |
279 | ||
6810df88 KRW |
280 | if (!ret) |
281 | return ret; | |
282 | ||
b097186f | 283 | if (hwdev && hwdev->coherent_dma_mask) |
b5031ed1 | 284 | dma_mask = dma_alloc_coherent_mask(hwdev, flags); |
b097186f | 285 | |
6810df88 KRW |
286 | phys = virt_to_phys(ret); |
287 | dev_addr = xen_phys_to_bus(phys); | |
288 | if (((dev_addr + size - 1 <= dma_mask)) && | |
289 | !range_straddles_page_boundary(phys, size)) | |
290 | *dma_handle = dev_addr; | |
291 | else { | |
b097186f KRW |
292 | if (xen_create_contiguous_region(vstart, order, |
293 | fls64(dma_mask)) != 0) { | |
294 | free_pages(vstart, order); | |
295 | return NULL; | |
296 | } | |
b097186f KRW |
297 | *dma_handle = virt_to_machine(ret).maddr; |
298 | } | |
6810df88 | 299 | memset(ret, 0, size); |
b097186f KRW |
300 | return ret; |
301 | } | |
302 | EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent); | |
303 | ||
304 | void | |
305 | xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, | |
baa676fc | 306 | dma_addr_t dev_addr, struct dma_attrs *attrs) |
b097186f KRW |
307 | { |
308 | int order = get_order(size); | |
6810df88 KRW |
309 | phys_addr_t phys; |
310 | u64 dma_mask = DMA_BIT_MASK(32); | |
b097186f KRW |
311 | |
312 | if (dma_release_from_coherent(hwdev, order, vaddr)) | |
313 | return; | |
314 | ||
6810df88 KRW |
315 | if (hwdev && hwdev->coherent_dma_mask) |
316 | dma_mask = hwdev->coherent_dma_mask; | |
317 | ||
318 | phys = virt_to_phys(vaddr); | |
319 | ||
320 | if (((dev_addr + size - 1 > dma_mask)) || | |
321 | range_straddles_page_boundary(phys, size)) | |
322 | xen_destroy_contiguous_region((unsigned long)vaddr, order); | |
323 | ||
b097186f KRW |
324 | free_pages((unsigned long)vaddr, order); |
325 | } | |
326 | EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); | |
327 | ||
328 | ||
329 | /* | |
330 | * Map a single buffer of the indicated size for DMA in streaming mode. The | |
331 | * physical address to use is returned. | |
332 | * | |
333 | * Once the device is given the dma address, the device owns this memory until | |
334 | * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed. | |
335 | */ | |
336 | dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, | |
337 | unsigned long offset, size_t size, | |
338 | enum dma_data_direction dir, | |
339 | struct dma_attrs *attrs) | |
340 | { | |
341 | phys_addr_t phys = page_to_phys(page) + offset; | |
342 | dma_addr_t dev_addr = xen_phys_to_bus(phys); | |
343 | void *map; | |
344 | ||
345 | BUG_ON(dir == DMA_NONE); | |
346 | /* | |
347 | * If the address happens to be in the device's DMA window, | |
348 | * we can safely return the device addr and not worry about bounce | |
349 | * buffering it. | |
350 | */ | |
351 | if (dma_capable(dev, dev_addr, size) && | |
352 | !range_straddles_page_boundary(phys, size) && !swiotlb_force) | |
353 | return dev_addr; | |
354 | ||
355 | /* | |
356 | * Oh well, have to allocate and map a bounce buffer. | |
357 | */ | |
358 | map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir); | |
359 | if (!map) | |
360 | return DMA_ERROR_CODE; | |
361 | ||
362 | dev_addr = xen_virt_to_bus(map); | |
363 | ||
364 | /* | |
365 | * Ensure that the address returned is DMA'ble | |
366 | */ | |
ab2a47bd KRW |
367 | if (!dma_capable(dev, dev_addr, size)) { |
368 | swiotlb_tbl_unmap_single(dev, map, size, dir); | |
369 | dev_addr = 0; | |
370 | } | |
b097186f KRW |
371 | return dev_addr; |
372 | } | |
373 | EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); | |
374 | ||
375 | /* | |
376 | * Unmap a single streaming mode DMA translation. The dma_addr and size must | |
377 | * match what was provided for in a previous xen_swiotlb_map_page call. All | |
378 | * other usages are undefined. | |
379 | * | |
380 | * After this call, reads by the cpu to the buffer are guaranteed to see | |
381 | * whatever the device wrote there. | |
382 | */ | |
383 | static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, | |
384 | size_t size, enum dma_data_direction dir) | |
385 | { | |
386 | phys_addr_t paddr = xen_bus_to_phys(dev_addr); | |
387 | ||
388 | BUG_ON(dir == DMA_NONE); | |
389 | ||
390 | /* NOTE: We use dev_addr here, not paddr! */ | |
391 | if (is_xen_swiotlb_buffer(dev_addr)) { | |
392 | swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir); | |
393 | return; | |
394 | } | |
395 | ||
396 | if (dir != DMA_FROM_DEVICE) | |
397 | return; | |
398 | ||
399 | /* | |
400 | * phys_to_virt doesn't work with hihgmem page but we could | |
401 | * call dma_mark_clean() with hihgmem page here. However, we | |
402 | * are fine since dma_mark_clean() is null on POWERPC. We can | |
403 | * make dma_mark_clean() take a physical address if necessary. | |
404 | */ | |
405 | dma_mark_clean(phys_to_virt(paddr), size); | |
406 | } | |
407 | ||
408 | void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, | |
409 | size_t size, enum dma_data_direction dir, | |
410 | struct dma_attrs *attrs) | |
411 | { | |
412 | xen_unmap_single(hwdev, dev_addr, size, dir); | |
413 | } | |
414 | EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page); | |
415 | ||
416 | /* | |
417 | * Make physical memory consistent for a single streaming mode DMA translation | |
418 | * after a transfer. | |
419 | * | |
420 | * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer | |
421 | * using the cpu, yet do not wish to teardown the dma mapping, you must | |
422 | * call this function before doing so. At the next point you give the dma | |
423 | * address back to the card, you must first perform a | |
424 | * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer | |
425 | */ | |
426 | static void | |
427 | xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, | |
428 | size_t size, enum dma_data_direction dir, | |
429 | enum dma_sync_target target) | |
430 | { | |
431 | phys_addr_t paddr = xen_bus_to_phys(dev_addr); | |
432 | ||
433 | BUG_ON(dir == DMA_NONE); | |
434 | ||
435 | /* NOTE: We use dev_addr here, not paddr! */ | |
436 | if (is_xen_swiotlb_buffer(dev_addr)) { | |
437 | swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir, | |
438 | target); | |
439 | return; | |
440 | } | |
441 | ||
442 | if (dir != DMA_FROM_DEVICE) | |
443 | return; | |
444 | ||
445 | dma_mark_clean(phys_to_virt(paddr), size); | |
446 | } | |
447 | ||
448 | void | |
449 | xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, | |
450 | size_t size, enum dma_data_direction dir) | |
451 | { | |
452 | xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); | |
453 | } | |
454 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_cpu); | |
455 | ||
456 | void | |
457 | xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, | |
458 | size_t size, enum dma_data_direction dir) | |
459 | { | |
460 | xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_single_for_device); | |
463 | ||
464 | /* | |
465 | * Map a set of buffers described by scatterlist in streaming mode for DMA. | |
466 | * This is the scatter-gather version of the above xen_swiotlb_map_page | |
467 | * interface. Here the scatter gather list elements are each tagged with the | |
468 | * appropriate dma address and length. They are obtained via | |
469 | * sg_dma_{address,length}(SG). | |
470 | * | |
471 | * NOTE: An implementation may be able to use a smaller number of | |
472 | * DMA address/length pairs than there are SG table elements. | |
473 | * (for example via virtual mapping capabilities) | |
474 | * The routine returns the number of addr/length pairs actually | |
475 | * used, at most nents. | |
476 | * | |
477 | * Device ownership issues as mentioned above for xen_swiotlb_map_page are the | |
478 | * same here. | |
479 | */ | |
480 | int | |
481 | xen_swiotlb_map_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 | phys_addr_t paddr = sg_phys(sg); | |
492 | dma_addr_t dev_addr = xen_phys_to_bus(paddr); | |
493 | ||
494 | if (swiotlb_force || | |
495 | !dma_capable(hwdev, dev_addr, sg->length) || | |
496 | range_straddles_page_boundary(paddr, sg->length)) { | |
497 | void *map = swiotlb_tbl_map_single(hwdev, | |
498 | start_dma_addr, | |
499 | sg_phys(sg), | |
500 | sg->length, dir); | |
501 | if (!map) { | |
502 | /* Don't panic here, we expect map_sg users | |
503 | to do proper error handling. */ | |
504 | xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, | |
505 | attrs); | |
506 | sgl[0].dma_length = 0; | |
507 | return DMA_ERROR_CODE; | |
508 | } | |
509 | sg->dma_address = xen_virt_to_bus(map); | |
510 | } else | |
511 | sg->dma_address = dev_addr; | |
512 | sg->dma_length = sg->length; | |
513 | } | |
514 | return nelems; | |
515 | } | |
516 | EXPORT_SYMBOL_GPL(xen_swiotlb_map_sg_attrs); | |
517 | ||
b097186f KRW |
518 | /* |
519 | * Unmap a set of streaming mode DMA translations. Again, cpu read rules | |
520 | * concerning calls here are the same as for swiotlb_unmap_page() above. | |
521 | */ | |
522 | void | |
523 | xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, | |
524 | int nelems, enum dma_data_direction dir, | |
525 | struct dma_attrs *attrs) | |
526 | { | |
527 | struct scatterlist *sg; | |
528 | int i; | |
529 | ||
530 | BUG_ON(dir == DMA_NONE); | |
531 | ||
532 | for_each_sg(sgl, sg, nelems, i) | |
533 | xen_unmap_single(hwdev, sg->dma_address, sg->dma_length, dir); | |
534 | ||
535 | } | |
536 | EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs); | |
537 | ||
b097186f KRW |
538 | /* |
539 | * Make physical memory consistent for a set of streaming mode DMA translations | |
540 | * after a transfer. | |
541 | * | |
542 | * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules | |
543 | * and usage. | |
544 | */ | |
545 | static void | |
546 | xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, | |
547 | int nelems, enum dma_data_direction dir, | |
548 | enum dma_sync_target target) | |
549 | { | |
550 | struct scatterlist *sg; | |
551 | int i; | |
552 | ||
553 | for_each_sg(sgl, sg, nelems, i) | |
554 | xen_swiotlb_sync_single(hwdev, sg->dma_address, | |
555 | sg->dma_length, dir, target); | |
556 | } | |
557 | ||
558 | void | |
559 | xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, | |
560 | int nelems, enum dma_data_direction dir) | |
561 | { | |
562 | xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); | |
563 | } | |
564 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_cpu); | |
565 | ||
566 | void | |
567 | xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, | |
568 | int nelems, enum dma_data_direction dir) | |
569 | { | |
570 | xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); | |
571 | } | |
572 | EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device); | |
573 | ||
574 | int | |
575 | xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr) | |
576 | { | |
577 | return !dma_addr; | |
578 | } | |
579 | EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error); | |
580 | ||
581 | /* | |
582 | * Return whether the given device DMA address mask can be supported | |
583 | * properly. For example, if your device can only drive the low 24-bits | |
584 | * during bus mastering, then you would pass 0x00ffffff as the mask to | |
585 | * this function. | |
586 | */ | |
587 | int | |
588 | xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) | |
589 | { | |
590 | return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask; | |
591 | } | |
592 | EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported); |