x86, AMD IOMMU: add mapping functions for coherent mappings
[h-e-n] / arch / x86 / kernel / amd_iommu.c
1 /*
2  * Copyright (C) 2007-2008 Advanced Micro Devices, Inc.
3  * Author: Joerg Roedel <joerg.roedel@amd.com>
4  *         Leo Duran <leo.duran@amd.com>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published
8  * by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18  */
19
20 #include <linux/pci.h>
21 #include <linux/gfp.h>
22 #include <linux/bitops.h>
23 #include <linux/scatterlist.h>
24 #include <linux/iommu-helper.h>
25 #include <asm/proto.h>
26 #include <asm/gart.h>
27 #include <asm/amd_iommu_types.h>
28
29 #define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
30
31 #define to_pages(addr, size) \
32          (round_up(((addr) & ~PAGE_MASK) + (size), PAGE_SIZE) >> PAGE_SHIFT)
33
34 static DEFINE_RWLOCK(amd_iommu_devtable_lock);
35
36 struct command {
37         u32 data[4];
38 };
39
40 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
41                              struct unity_map_entry *e);
42
43 static int iommu_has_npcache(struct amd_iommu *iommu)
44 {
45         return iommu->cap & IOMMU_CAP_NPCACHE;
46 }
47
48 static int __iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
49 {
50         u32 tail, head;
51         u8 *target;
52
53         tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
54         target = (iommu->cmd_buf + tail);
55         memcpy_toio(target, cmd, sizeof(*cmd));
56         tail = (tail + sizeof(*cmd)) % iommu->cmd_buf_size;
57         head = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
58         if (tail == head)
59                 return -ENOMEM;
60         writel(tail, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
61
62         return 0;
63 }
64
65 static int iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
66 {
67         unsigned long flags;
68         int ret;
69
70         spin_lock_irqsave(&iommu->lock, flags);
71         ret = __iommu_queue_command(iommu, cmd);
72         spin_unlock_irqrestore(&iommu->lock, flags);
73
74         return ret;
75 }
76
77 static int iommu_completion_wait(struct amd_iommu *iommu)
78 {
79         int ret;
80         struct command cmd;
81         volatile u64 ready = 0;
82         unsigned long ready_phys = virt_to_phys(&ready);
83
84         memset(&cmd, 0, sizeof(cmd));
85         cmd.data[0] = LOW_U32(ready_phys) | CMD_COMPL_WAIT_STORE_MASK;
86         cmd.data[1] = HIGH_U32(ready_phys);
87         cmd.data[2] = 1; /* value written to 'ready' */
88         CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
89
90         iommu->need_sync = 0;
91
92         ret = iommu_queue_command(iommu, &cmd);
93
94         if (ret)
95                 return ret;
96
97         while (!ready)
98                 cpu_relax();
99
100         return 0;
101 }
102
103 static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
104 {
105         struct command cmd;
106
107         BUG_ON(iommu == NULL);
108
109         memset(&cmd, 0, sizeof(cmd));
110         CMD_SET_TYPE(&cmd, CMD_INV_DEV_ENTRY);
111         cmd.data[0] = devid;
112
113         iommu->need_sync = 1;
114
115         return iommu_queue_command(iommu, &cmd);
116 }
117
118 static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu,
119                 u64 address, u16 domid, int pde, int s)
120 {
121         struct command cmd;
122
123         memset(&cmd, 0, sizeof(cmd));
124         address &= PAGE_MASK;
125         CMD_SET_TYPE(&cmd, CMD_INV_IOMMU_PAGES);
126         cmd.data[1] |= domid;
127         cmd.data[2] = LOW_U32(address);
128         cmd.data[3] = HIGH_U32(address);
129         if (s)
130                 cmd.data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK;
131         if (pde)
132                 cmd.data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK;
133
134         iommu->need_sync = 1;
135
136         return iommu_queue_command(iommu, &cmd);
137 }
138
139 static int iommu_flush_pages(struct amd_iommu *iommu, u16 domid,
140                 u64 address, size_t size)
141 {
142         int i;
143         unsigned pages = to_pages(address, size);
144
145         address &= PAGE_MASK;
146
147         for (i = 0; i < pages; ++i) {
148                 iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 0);
149                 address += PAGE_SIZE;
150         }
151
152         return 0;
153 }
154
155 static int iommu_map(struct protection_domain *dom,
156                      unsigned long bus_addr,
157                      unsigned long phys_addr,
158                      int prot)
159 {
160         u64 __pte, *pte, *page;
161
162         bus_addr  = PAGE_ALIGN(bus_addr);
163         phys_addr = PAGE_ALIGN(bus_addr);
164
165         /* only support 512GB address spaces for now */
166         if (bus_addr > IOMMU_MAP_SIZE_L3 || !(prot & IOMMU_PROT_MASK))
167                 return -EINVAL;
168
169         pte = &dom->pt_root[IOMMU_PTE_L2_INDEX(bus_addr)];
170
171         if (!IOMMU_PTE_PRESENT(*pte)) {
172                 page = (u64 *)get_zeroed_page(GFP_KERNEL);
173                 if (!page)
174                         return -ENOMEM;
175                 *pte = IOMMU_L2_PDE(virt_to_phys(page));
176         }
177
178         pte = IOMMU_PTE_PAGE(*pte);
179         pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)];
180
181         if (!IOMMU_PTE_PRESENT(*pte)) {
182                 page = (u64 *)get_zeroed_page(GFP_KERNEL);
183                 if (!page)
184                         return -ENOMEM;
185                 *pte = IOMMU_L1_PDE(virt_to_phys(page));
186         }
187
188         pte = IOMMU_PTE_PAGE(*pte);
189         pte = &pte[IOMMU_PTE_L0_INDEX(bus_addr)];
190
191         if (IOMMU_PTE_PRESENT(*pte))
192                 return -EBUSY;
193
194         __pte = phys_addr | IOMMU_PTE_P;
195         if (prot & IOMMU_PROT_IR)
196                 __pte |= IOMMU_PTE_IR;
197         if (prot & IOMMU_PROT_IW)
198                 __pte |= IOMMU_PTE_IW;
199
200         *pte = __pte;
201
202         return 0;
203 }
204
205 static int iommu_for_unity_map(struct amd_iommu *iommu,
206                                struct unity_map_entry *entry)
207 {
208         u16 bdf, i;
209
210         for (i = entry->devid_start; i <= entry->devid_end; ++i) {
211                 bdf = amd_iommu_alias_table[i];
212                 if (amd_iommu_rlookup_table[bdf] == iommu)
213                         return 1;
214         }
215
216         return 0;
217 }
218
219 static int iommu_init_unity_mappings(struct amd_iommu *iommu)
220 {
221         struct unity_map_entry *entry;
222         int ret;
223
224         list_for_each_entry(entry, &amd_iommu_unity_map, list) {
225                 if (!iommu_for_unity_map(iommu, entry))
226                         continue;
227                 ret = dma_ops_unity_map(iommu->default_dom, entry);
228                 if (ret)
229                         return ret;
230         }
231
232         return 0;
233 }
234
235 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
236                              struct unity_map_entry *e)
237 {
238         u64 addr;
239         int ret;
240
241         for (addr = e->address_start; addr < e->address_end;
242              addr += PAGE_SIZE) {
243                 ret = iommu_map(&dma_dom->domain, addr, addr, e->prot);
244                 if (ret)
245                         return ret;
246                 /*
247                  * if unity mapping is in aperture range mark the page
248                  * as allocated in the aperture
249                  */
250                 if (addr < dma_dom->aperture_size)
251                         __set_bit(addr >> PAGE_SHIFT, dma_dom->bitmap);
252         }
253
254         return 0;
255 }
256
257 static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
258                                           u16 devid)
259 {
260         struct unity_map_entry *e;
261         int ret;
262
263         list_for_each_entry(e, &amd_iommu_unity_map, list) {
264                 if (!(devid >= e->devid_start && devid <= e->devid_end))
265                         continue;
266                 ret = dma_ops_unity_map(dma_dom, e);
267                 if (ret)
268                         return ret;
269         }
270
271         return 0;
272 }
273
274 static unsigned long dma_mask_to_pages(unsigned long mask)
275 {
276         return (mask >> PAGE_SHIFT) +
277                 (PAGE_ALIGN(mask & ~PAGE_MASK) >> PAGE_SHIFT);
278 }
279
280 static unsigned long dma_ops_alloc_addresses(struct device *dev,
281                                              struct dma_ops_domain *dom,
282                                              unsigned int pages)
283 {
284         unsigned long limit = dma_mask_to_pages(*dev->dma_mask);
285         unsigned long address;
286         unsigned long size = dom->aperture_size >> PAGE_SHIFT;
287         unsigned long boundary_size;
288
289         boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
290                         PAGE_SIZE) >> PAGE_SHIFT;
291         limit = limit < size ? limit : size;
292
293         if (dom->next_bit >= limit)
294                 dom->next_bit = 0;
295
296         address = iommu_area_alloc(dom->bitmap, limit, dom->next_bit, pages,
297                         0 , boundary_size, 0);
298         if (address == -1)
299                 address = iommu_area_alloc(dom->bitmap, limit, 0, pages,
300                                 0, boundary_size, 0);
301
302         if (likely(address != -1)) {
303                 set_bit_string(dom->bitmap, address, pages);
304                 dom->next_bit = address + pages;
305                 address <<= PAGE_SHIFT;
306         } else
307                 address = bad_dma_address;
308
309         WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size);
310
311         return address;
312 }
313
314 static void dma_ops_free_addresses(struct dma_ops_domain *dom,
315                                    unsigned long address,
316                                    unsigned int pages)
317 {
318         address >>= PAGE_SHIFT;
319         iommu_area_free(dom->bitmap, address, pages);
320 }
321
322 static u16 domain_id_alloc(void)
323 {
324         unsigned long flags;
325         int id;
326
327         write_lock_irqsave(&amd_iommu_devtable_lock, flags);
328         id = find_first_zero_bit(amd_iommu_pd_alloc_bitmap, MAX_DOMAIN_ID);
329         BUG_ON(id == 0);
330         if (id > 0 && id < MAX_DOMAIN_ID)
331                 __set_bit(id, amd_iommu_pd_alloc_bitmap);
332         else
333                 id = 0;
334         write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
335
336         return id;
337 }
338
339 static void dma_ops_reserve_addresses(struct dma_ops_domain *dom,
340                                       unsigned long start_page,
341                                       unsigned int pages)
342 {
343         unsigned int last_page = dom->aperture_size >> PAGE_SHIFT;
344
345         if (start_page + pages > last_page)
346                 pages = last_page - start_page;
347
348         set_bit_string(dom->bitmap, start_page, pages);
349 }
350
351 static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom)
352 {
353         int i, j;
354         u64 *p1, *p2, *p3;
355
356         p1 = dma_dom->domain.pt_root;
357
358         if (!p1)
359                 return;
360
361         for (i = 0; i < 512; ++i) {
362                 if (!IOMMU_PTE_PRESENT(p1[i]))
363                         continue;
364
365                 p2 = IOMMU_PTE_PAGE(p1[i]);
366                 for (j = 0; j < 512; ++i) {
367                         if (!IOMMU_PTE_PRESENT(p2[j]))
368                                 continue;
369                         p3 = IOMMU_PTE_PAGE(p2[j]);
370                         free_page((unsigned long)p3);
371                 }
372
373                 free_page((unsigned long)p2);
374         }
375
376         free_page((unsigned long)p1);
377 }
378
379 static void dma_ops_domain_free(struct dma_ops_domain *dom)
380 {
381         if (!dom)
382                 return;
383
384         dma_ops_free_pagetable(dom);
385
386         kfree(dom->pte_pages);
387
388         kfree(dom->bitmap);
389
390         kfree(dom);
391 }
392
393 static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu,
394                                                    unsigned order)
395 {
396         struct dma_ops_domain *dma_dom;
397         unsigned i, num_pte_pages;
398         u64 *l2_pde;
399         u64 address;
400
401         /*
402          * Currently the DMA aperture must be between 32 MB and 1GB in size
403          */
404         if ((order < 25) || (order > 30))
405                 return NULL;
406
407         dma_dom = kzalloc(sizeof(struct dma_ops_domain), GFP_KERNEL);
408         if (!dma_dom)
409                 return NULL;
410
411         spin_lock_init(&dma_dom->domain.lock);
412
413         dma_dom->domain.id = domain_id_alloc();
414         if (dma_dom->domain.id == 0)
415                 goto free_dma_dom;
416         dma_dom->domain.mode = PAGE_MODE_3_LEVEL;
417         dma_dom->domain.pt_root = (void *)get_zeroed_page(GFP_KERNEL);
418         dma_dom->domain.priv = dma_dom;
419         if (!dma_dom->domain.pt_root)
420                 goto free_dma_dom;
421         dma_dom->aperture_size = (1ULL << order);
422         dma_dom->bitmap = kzalloc(dma_dom->aperture_size / (PAGE_SIZE * 8),
423                                   GFP_KERNEL);
424         if (!dma_dom->bitmap)
425                 goto free_dma_dom;
426         /*
427          * mark the first page as allocated so we never return 0 as
428          * a valid dma-address. So we can use 0 as error value
429          */
430         dma_dom->bitmap[0] = 1;
431         dma_dom->next_bit = 0;
432
433         if (iommu->exclusion_start &&
434             iommu->exclusion_start < dma_dom->aperture_size) {
435                 unsigned long startpage = iommu->exclusion_start >> PAGE_SHIFT;
436                 int pages = to_pages(iommu->exclusion_start,
437                                 iommu->exclusion_length);
438                 dma_ops_reserve_addresses(dma_dom, startpage, pages);
439         }
440
441         num_pte_pages = dma_dom->aperture_size / (PAGE_SIZE * 512);
442         dma_dom->pte_pages = kzalloc(num_pte_pages * sizeof(void *),
443                         GFP_KERNEL);
444         if (!dma_dom->pte_pages)
445                 goto free_dma_dom;
446
447         l2_pde = (u64 *)get_zeroed_page(GFP_KERNEL);
448         if (l2_pde == NULL)
449                 goto free_dma_dom;
450
451         dma_dom->domain.pt_root[0] = IOMMU_L2_PDE(virt_to_phys(l2_pde));
452
453         for (i = 0; i < num_pte_pages; ++i) {
454                 dma_dom->pte_pages[i] = (u64 *)get_zeroed_page(GFP_KERNEL);
455                 if (!dma_dom->pte_pages[i])
456                         goto free_dma_dom;
457                 address = virt_to_phys(dma_dom->pte_pages[i]);
458                 l2_pde[i] = IOMMU_L1_PDE(address);
459         }
460
461         return dma_dom;
462
463 free_dma_dom:
464         dma_ops_domain_free(dma_dom);
465
466         return NULL;
467 }
468
469 static struct protection_domain *domain_for_device(u16 devid)
470 {
471         struct protection_domain *dom;
472         unsigned long flags;
473
474         read_lock_irqsave(&amd_iommu_devtable_lock, flags);
475         dom = amd_iommu_pd_table[devid];
476         read_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
477
478         return dom;
479 }
480
481 static void set_device_domain(struct amd_iommu *iommu,
482                               struct protection_domain *domain,
483                               u16 devid)
484 {
485         unsigned long flags;
486
487         u64 pte_root = virt_to_phys(domain->pt_root);
488
489         pte_root |= (domain->mode & 0x07) << 9;
490         pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | 2;
491
492         write_lock_irqsave(&amd_iommu_devtable_lock, flags);
493         amd_iommu_dev_table[devid].data[0] = pte_root;
494         amd_iommu_dev_table[devid].data[1] = pte_root >> 32;
495         amd_iommu_dev_table[devid].data[2] = domain->id;
496
497         amd_iommu_pd_table[devid] = domain;
498         write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
499
500         iommu_queue_inv_dev_entry(iommu, devid);
501
502         iommu->need_sync = 1;
503 }
504
505 static int get_device_resources(struct device *dev,
506                                 struct amd_iommu **iommu,
507                                 struct protection_domain **domain,
508                                 u16 *bdf)
509 {
510         struct dma_ops_domain *dma_dom;
511         struct pci_dev *pcidev;
512         u16 _bdf;
513
514         BUG_ON(!dev || dev->bus != &pci_bus_type || !dev->dma_mask);
515
516         pcidev = to_pci_dev(dev);
517         _bdf = (pcidev->bus->number << 8) | pcidev->devfn;
518
519         if (_bdf >= amd_iommu_last_bdf) {
520                 *iommu = NULL;
521                 *domain = NULL;
522                 *bdf = 0xffff;
523                 return 0;
524         }
525
526         *bdf = amd_iommu_alias_table[_bdf];
527
528         *iommu = amd_iommu_rlookup_table[*bdf];
529         if (*iommu == NULL)
530                 return 0;
531         dma_dom = (*iommu)->default_dom;
532         *domain = domain_for_device(*bdf);
533         if (*domain == NULL) {
534                 *domain = &dma_dom->domain;
535                 set_device_domain(*iommu, *domain, *bdf);
536                 printk(KERN_INFO "AMD IOMMU: Using protection domain %d for "
537                                 "device ", (*domain)->id);
538                 print_devid(_bdf, 1);
539         }
540
541         return 1;
542 }
543
544 static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
545                                      struct dma_ops_domain *dom,
546                                      unsigned long address,
547                                      phys_addr_t paddr,
548                                      int direction)
549 {
550         u64 *pte, __pte;
551
552         WARN_ON(address > dom->aperture_size);
553
554         paddr &= PAGE_MASK;
555
556         pte  = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)];
557         pte += IOMMU_PTE_L0_INDEX(address);
558
559         __pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC;
560
561         if (direction == DMA_TO_DEVICE)
562                 __pte |= IOMMU_PTE_IR;
563         else if (direction == DMA_FROM_DEVICE)
564                 __pte |= IOMMU_PTE_IW;
565         else if (direction == DMA_BIDIRECTIONAL)
566                 __pte |= IOMMU_PTE_IR | IOMMU_PTE_IW;
567
568         WARN_ON(*pte);
569
570         *pte = __pte;
571
572         return (dma_addr_t)address;
573 }
574
575 static void dma_ops_domain_unmap(struct amd_iommu *iommu,
576                                  struct dma_ops_domain *dom,
577                                  unsigned long address)
578 {
579         u64 *pte;
580
581         if (address >= dom->aperture_size)
582                 return;
583
584         WARN_ON(address & 0xfffULL || address > dom->aperture_size);
585
586         pte  = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)];
587         pte += IOMMU_PTE_L0_INDEX(address);
588
589         WARN_ON(!*pte);
590
591         *pte = 0ULL;
592 }
593
594 static dma_addr_t __map_single(struct device *dev,
595                                struct amd_iommu *iommu,
596                                struct dma_ops_domain *dma_dom,
597                                phys_addr_t paddr,
598                                size_t size,
599                                int dir)
600 {
601         dma_addr_t offset = paddr & ~PAGE_MASK;
602         dma_addr_t address, start;
603         unsigned int pages;
604         int i;
605
606         pages = to_pages(paddr, size);
607         paddr &= PAGE_MASK;
608
609         address = dma_ops_alloc_addresses(dev, dma_dom, pages);
610         if (unlikely(address == bad_dma_address))
611                 goto out;
612
613         start = address;
614         for (i = 0; i < pages; ++i) {
615                 dma_ops_domain_map(iommu, dma_dom, start, paddr, dir);
616                 paddr += PAGE_SIZE;
617                 start += PAGE_SIZE;
618         }
619         address += offset;
620
621 out:
622         return address;
623 }
624
625 static void __unmap_single(struct amd_iommu *iommu,
626                            struct dma_ops_domain *dma_dom,
627                            dma_addr_t dma_addr,
628                            size_t size,
629                            int dir)
630 {
631         dma_addr_t i, start;
632         unsigned int pages;
633
634         if ((dma_addr == 0) || (dma_addr + size > dma_dom->aperture_size))
635                 return;
636
637         pages = to_pages(dma_addr, size);
638         dma_addr &= PAGE_MASK;
639         start = dma_addr;
640
641         for (i = 0; i < pages; ++i) {
642                 dma_ops_domain_unmap(iommu, dma_dom, start);
643                 start += PAGE_SIZE;
644         }
645
646         dma_ops_free_addresses(dma_dom, dma_addr, pages);
647 }
648
649 static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
650                              size_t size, int dir)
651 {
652         unsigned long flags;
653         struct amd_iommu *iommu;
654         struct protection_domain *domain;
655         u16 devid;
656         dma_addr_t addr;
657
658         get_device_resources(dev, &iommu, &domain, &devid);
659
660         if (iommu == NULL || domain == NULL)
661                 return (dma_addr_t)paddr;
662
663         spin_lock_irqsave(&domain->lock, flags);
664         addr = __map_single(dev, iommu, domain->priv, paddr, size, dir);
665         if (addr == bad_dma_address)
666                 goto out;
667
668         if (iommu_has_npcache(iommu))
669                 iommu_flush_pages(iommu, domain->id, addr, size);
670
671         if (iommu->need_sync)
672                 iommu_completion_wait(iommu);
673
674 out:
675         spin_unlock_irqrestore(&domain->lock, flags);
676
677         return addr;
678 }
679
680 static void unmap_single(struct device *dev, dma_addr_t dma_addr,
681                          size_t size, int dir)
682 {
683         unsigned long flags;
684         struct amd_iommu *iommu;
685         struct protection_domain *domain;
686         u16 devid;
687
688         if (!get_device_resources(dev, &iommu, &domain, &devid))
689                 return;
690
691         spin_lock_irqsave(&domain->lock, flags);
692
693         __unmap_single(iommu, domain->priv, dma_addr, size, dir);
694
695         iommu_flush_pages(iommu, domain->id, dma_addr, size);
696
697         if (iommu->need_sync)
698                 iommu_completion_wait(iommu);
699
700         spin_unlock_irqrestore(&domain->lock, flags);
701 }
702
703 static int map_sg_no_iommu(struct device *dev, struct scatterlist *sglist,
704                            int nelems, int dir)
705 {
706         struct scatterlist *s;
707         int i;
708
709         for_each_sg(sglist, s, nelems, i) {
710                 s->dma_address = (dma_addr_t)sg_phys(s);
711                 s->dma_length  = s->length;
712         }
713
714         return nelems;
715 }
716
717 static int map_sg(struct device *dev, struct scatterlist *sglist,
718                   int nelems, int dir)
719 {
720         unsigned long flags;
721         struct amd_iommu *iommu;
722         struct protection_domain *domain;
723         u16 devid;
724         int i;
725         struct scatterlist *s;
726         phys_addr_t paddr;
727         int mapped_elems = 0;
728
729         get_device_resources(dev, &iommu, &domain, &devid);
730
731         if (!iommu || !domain)
732                 return map_sg_no_iommu(dev, sglist, nelems, dir);
733
734         spin_lock_irqsave(&domain->lock, flags);
735
736         for_each_sg(sglist, s, nelems, i) {
737                 paddr = sg_phys(s);
738
739                 s->dma_address = __map_single(dev, iommu, domain->priv,
740                                               paddr, s->length, dir);
741
742                 if (s->dma_address) {
743                         s->dma_length = s->length;
744                         mapped_elems++;
745                 } else
746                         goto unmap;
747                 if (iommu_has_npcache(iommu))
748                         iommu_flush_pages(iommu, domain->id, s->dma_address,
749                                           s->dma_length);
750         }
751
752         if (iommu->need_sync)
753                 iommu_completion_wait(iommu);
754
755 out:
756         spin_unlock_irqrestore(&domain->lock, flags);
757
758         return mapped_elems;
759 unmap:
760         for_each_sg(sglist, s, mapped_elems, i) {
761                 if (s->dma_address)
762                         __unmap_single(iommu, domain->priv, s->dma_address,
763                                        s->dma_length, dir);
764                 s->dma_address = s->dma_length = 0;
765         }
766
767         mapped_elems = 0;
768
769         goto out;
770 }
771
772 static void unmap_sg(struct device *dev, struct scatterlist *sglist,
773                      int nelems, int dir)
774 {
775         unsigned long flags;
776         struct amd_iommu *iommu;
777         struct protection_domain *domain;
778         struct scatterlist *s;
779         u16 devid;
780         int i;
781
782         if (!get_device_resources(dev, &iommu, &domain, &devid))
783                 return;
784
785         spin_lock_irqsave(&domain->lock, flags);
786
787         for_each_sg(sglist, s, nelems, i) {
788                 __unmap_single(iommu, domain->priv, s->dma_address,
789                                s->dma_length, dir);
790                 iommu_flush_pages(iommu, domain->id, s->dma_address,
791                                   s->dma_length);
792                 s->dma_address = s->dma_length = 0;
793         }
794
795         if (iommu->need_sync)
796                 iommu_completion_wait(iommu);
797
798         spin_unlock_irqrestore(&domain->lock, flags);
799 }
800
801 static void *alloc_coherent(struct device *dev, size_t size,
802                             dma_addr_t *dma_addr, gfp_t flag)
803 {
804         unsigned long flags;
805         void *virt_addr;
806         struct amd_iommu *iommu;
807         struct protection_domain *domain;
808         u16 devid;
809         phys_addr_t paddr;
810
811         virt_addr = (void *)__get_free_pages(flag, get_order(size));
812         if (!virt_addr)
813                 return 0;
814
815         memset(virt_addr, 0, size);
816         paddr = virt_to_phys(virt_addr);
817
818         get_device_resources(dev, &iommu, &domain, &devid);
819
820         if (!iommu || !domain) {
821                 *dma_addr = (dma_addr_t)paddr;
822                 return virt_addr;
823         }
824
825         spin_lock_irqsave(&domain->lock, flags);
826
827         *dma_addr = __map_single(dev, iommu, domain->priv, paddr,
828                                  size, DMA_BIDIRECTIONAL);
829
830         if (*dma_addr == bad_dma_address) {
831                 free_pages((unsigned long)virt_addr, get_order(size));
832                 virt_addr = NULL;
833                 goto out;
834         }
835
836         if (iommu_has_npcache(iommu))
837                 iommu_flush_pages(iommu, domain->id, *dma_addr, size);
838
839         if (iommu->need_sync)
840                 iommu_completion_wait(iommu);
841
842 out:
843         spin_unlock_irqrestore(&domain->lock, flags);
844
845         return virt_addr;
846 }
847
848 static void free_coherent(struct device *dev, size_t size,
849                           void *virt_addr, dma_addr_t dma_addr)
850 {
851         unsigned long flags;
852         struct amd_iommu *iommu;
853         struct protection_domain *domain;
854         u16 devid;
855
856         get_device_resources(dev, &iommu, &domain, &devid);
857
858         if (!iommu || !domain)
859                 goto free_mem;
860
861         spin_lock_irqsave(&domain->lock, flags);
862
863         __unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL);
864         iommu_flush_pages(iommu, domain->id, dma_addr, size);
865
866         if (iommu->need_sync)
867                 iommu_completion_wait(iommu);
868
869         spin_unlock_irqrestore(&domain->lock, flags);
870
871 free_mem:
872         free_pages((unsigned long)virt_addr, get_order(size));
873 }
874