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iio: ep93xx: remove redundant return value check of platform_get_resource()
[linux-2.6/btrfs-unstable.git] / drivers / vfio / vfio_iommu_spapr_tce.c
blob759a5bdd40e1b37305f4fd850b60a87f1d3aafae
1 /*
2 * VFIO: IOMMU DMA mapping support for TCE on POWER
3 *
4 * Copyright (C) 2013 IBM Corp. All rights reserved.
5 * Author: Alexey Kardashevskiy <aik@ozlabs.ru>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Derived from original vfio_iommu_type1.c:
12 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
13 * Author: Alex Williamson <alex.williamson@redhat.com>
14 */
15
16 #include <linux/module.h>
17 #include <linux/pci.h>
18 #include <linux/slab.h>
19 #include <linux/uaccess.h>
20 #include <linux/err.h>
21 #include <linux/vfio.h>
22 #include <linux/vmalloc.h>
23 #include <linux/sched/mm.h>
24 #include <linux/sched/signal.h>
25
26 #include <asm/iommu.h>
27 #include <asm/tce.h>
28 #include <asm/mmu_context.h>
29
30 #define DRIVER_VERSION "0.1"
31 #define DRIVER_AUTHOR "aik@ozlabs.ru"
32 #define DRIVER_DESC "VFIO IOMMU SPAPR TCE"
33
34 static void tce_iommu_detach_group(void *iommu_data,
35 struct iommu_group *iommu_group);
36
37 static long try_increment_locked_vm(struct mm_struct *mm, long npages)
38 {
39 long ret = 0, locked, lock_limit;
40
41 if (WARN_ON_ONCE(!mm))
42 return -EPERM;
43
44 if (!npages)
45 return 0;
46
47 down_write(&mm->mmap_sem);
48 locked = mm->locked_vm + npages;
49 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
50 if (locked > lock_limit && !capable(CAP_IPC_LOCK))
51 ret = -ENOMEM;
52 else
53 mm->locked_vm += npages;
54
55 pr_debug("[%d] RLIMIT_MEMLOCK +%ld %ld/%ld%s\n", current->pid,
56 npages << PAGE_SHIFT,
57 mm->locked_vm << PAGE_SHIFT,
58 rlimit(RLIMIT_MEMLOCK),
59 ret ? " - exceeded" : "");
60
61 up_write(&mm->mmap_sem);
62
63 return ret;
64 }
65
66 static void decrement_locked_vm(struct mm_struct *mm, long npages)
67 {
68 if (!mm || !npages)
69 return;
70
71 down_write(&mm->mmap_sem);
72 if (WARN_ON_ONCE(npages > mm->locked_vm))
73 npages = mm->locked_vm;
74 mm->locked_vm -= npages;
75 pr_debug("[%d] RLIMIT_MEMLOCK -%ld %ld/%ld\n", current->pid,
76 npages << PAGE_SHIFT,
77 mm->locked_vm << PAGE_SHIFT,
78 rlimit(RLIMIT_MEMLOCK));
79 up_write(&mm->mmap_sem);
80 }
81
82 /*
83 * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
84 *
85 * This code handles mapping and unmapping of user data buffers
86 * into DMA'ble space using the IOMMU
87 */
88
89 struct tce_iommu_group {
90 struct list_head next;
91 struct iommu_group *grp;
92 };
93
94 /*
95 * A container needs to remember which preregistered region it has
96 * referenced to do proper cleanup at the userspace process exit.
97 */
98 struct tce_iommu_prereg {
99 struct list_head next;
100 struct mm_iommu_table_group_mem_t *mem;
101 };
102
103 /*
104 * The container descriptor supports only a single group per container.
105 * Required by the API as the container is not supplied with the IOMMU group
106 * at the moment of initialization.
107 */
108 struct tce_container {
109 struct mutex lock;
110 bool enabled;
111 bool v2;
112 bool def_window_pending;
113 unsigned long locked_pages;
114 struct mm_struct *mm;
115 struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
116 struct list_head group_list;
117 struct list_head prereg_list;
118 };
119
120 static long tce_iommu_mm_set(struct tce_container *container)
121 {
122 if (container->mm) {
123 if (container->mm == current->mm)
124 return 0;
125 return -EPERM;
126 }
127 BUG_ON(!current->mm);
128 container->mm = current->mm;
129 atomic_inc(&container->mm->mm_count);
130
131 return 0;
132 }
133
134 static long tce_iommu_prereg_free(struct tce_container *container,
135 struct tce_iommu_prereg *tcemem)
136 {
137 long ret;
138
139 ret = mm_iommu_put(container->mm, tcemem->mem);
140 if (ret)
141 return ret;
142
143 list_del(&tcemem->next);
144 kfree(tcemem);
145
146 return 0;
147 }
148
149 static long tce_iommu_unregister_pages(struct tce_container *container,
150 __u64 vaddr, __u64 size)
151 {
152 struct mm_iommu_table_group_mem_t *mem;
153 struct tce_iommu_prereg *tcemem;
154 bool found = false;
155
156 if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
157 return -EINVAL;
158
159 mem = mm_iommu_find(container->mm, vaddr, size >> PAGE_SHIFT);
160 if (!mem)
161 return -ENOENT;
162
163 list_for_each_entry(tcemem, &container->prereg_list, next) {
164 if (tcemem->mem == mem) {
165 found = true;
166 break;
167 }
168 }
169
170 if (!found)
171 return -ENOENT;
172
173 return tce_iommu_prereg_free(container, tcemem);
174 }
175
176 static long tce_iommu_register_pages(struct tce_container *container,
177 __u64 vaddr, __u64 size)
178 {
179 long ret = 0;
180 struct mm_iommu_table_group_mem_t *mem = NULL;
181 struct tce_iommu_prereg *tcemem;
182 unsigned long entries = size >> PAGE_SHIFT;
183
184 if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
185 ((vaddr + size) < vaddr))
186 return -EINVAL;
187
188 mem = mm_iommu_find(container->mm, vaddr, entries);
189 if (mem) {
190 list_for_each_entry(tcemem, &container->prereg_list, next) {
191 if (tcemem->mem == mem)
192 return -EBUSY;
193 }
194 }
195
196 ret = mm_iommu_get(container->mm, vaddr, entries, &mem);
197 if (ret)
198 return ret;
199
200 tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
201 if (!tcemem) {
202 mm_iommu_put(container->mm, mem);
203 return -ENOMEM;
204 }
205
206 tcemem->mem = mem;
207 list_add(&tcemem->next, &container->prereg_list);
208
209 container->enabled = true;
210
211 return 0;
212 }
213
214 static long tce_iommu_userspace_view_alloc(struct iommu_table *tbl,
215 struct mm_struct *mm)
216 {
217 unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) *
218 tbl->it_size, PAGE_SIZE);
219 unsigned long *uas;
220 long ret;
221
222 BUG_ON(tbl->it_userspace);
223
224 ret = try_increment_locked_vm(mm, cb >> PAGE_SHIFT);
225 if (ret)
226 return ret;
227
228 uas = vzalloc(cb);
229 if (!uas) {
230 decrement_locked_vm(mm, cb >> PAGE_SHIFT);
231 return -ENOMEM;
232 }
233 tbl->it_userspace = uas;
234
235 return 0;
236 }
237
238 static void tce_iommu_userspace_view_free(struct iommu_table *tbl,
239 struct mm_struct *mm)
240 {
241 unsigned long cb = _ALIGN_UP(sizeof(tbl->it_userspace[0]) *
242 tbl->it_size, PAGE_SIZE);
243
244 if (!tbl->it_userspace)
245 return;
246
247 vfree(tbl->it_userspace);
248 tbl->it_userspace = NULL;
249 decrement_locked_vm(mm, cb >> PAGE_SHIFT);
250 }
251
252 static bool tce_page_is_contained(struct page *page, unsigned page_shift)
253 {
254 /*
255 * Check that the TCE table granularity is not bigger than the size of
256 * a page we just found. Otherwise the hardware can get access to
257 * a bigger memory chunk that it should.
258 */
259 return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
260 }
261
262 static inline bool tce_groups_attached(struct tce_container *container)
263 {
264 return !list_empty(&container->group_list);
265 }
266
267 static long tce_iommu_find_table(struct tce_container *container,
268 phys_addr_t ioba, struct iommu_table **ptbl)
269 {
270 long i;
271
272 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
273 struct iommu_table *tbl = container->tables[i];
274
275 if (tbl) {
276 unsigned long entry = ioba >> tbl->it_page_shift;
277 unsigned long start = tbl->it_offset;
278 unsigned long end = start + tbl->it_size;
279
280 if ((start <= entry) && (entry < end)) {
281 *ptbl = tbl;
282 return i;
283 }
284 }
285 }
286
287 return -1;
288 }
289
290 static int tce_iommu_find_free_table(struct tce_container *container)
291 {
292 int i;
293
294 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
295 if (!container->tables[i])
296 return i;
297 }
298
299 return -ENOSPC;
300 }
301
302 static int tce_iommu_enable(struct tce_container *container)
303 {
304 int ret = 0;
305 unsigned long locked;
306 struct iommu_table_group *table_group;
307 struct tce_iommu_group *tcegrp;
308
309 if (container->enabled)
310 return -EBUSY;
311
312 /*
313 * When userspace pages are mapped into the IOMMU, they are effectively
314 * locked memory, so, theoretically, we need to update the accounting
315 * of locked pages on each map and unmap. For powerpc, the map unmap
316 * paths can be very hot, though, and the accounting would kill
317 * performance, especially since it would be difficult to impossible
318 * to handle the accounting in real mode only.
319 *
320 * To address that, rather than precisely accounting every page, we
321 * instead account for a worst case on locked memory when the iommu is
322 * enabled and disabled. The worst case upper bound on locked memory
323 * is the size of the whole iommu window, which is usually relatively
324 * small (compared to total memory sizes) on POWER hardware.
325 *
326 * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
327 * that would effectively kill the guest at random points, much better
328 * enforcing the limit based on the max that the guest can map.
329 *
330 * Unfortunately at the moment it counts whole tables, no matter how
331 * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
332 * each with 2GB DMA window, 8GB will be counted here. The reason for
333 * this is that we cannot tell here the amount of RAM used by the guest
334 * as this information is only available from KVM and VFIO is
335 * KVM agnostic.
336 *
337 * So we do not allow enabling a container without a group attached
338 * as there is no way to know how much we should increment
339 * the locked_vm counter.
340 */
341 if (!tce_groups_attached(container))
342 return -ENODEV;
343
344 tcegrp = list_first_entry(&container->group_list,
345 struct tce_iommu_group, next);
346 table_group = iommu_group_get_iommudata(tcegrp->grp);
347 if (!table_group)
348 return -ENODEV;
349
350 if (!table_group->tce32_size)
351 return -EPERM;
352
353 ret = tce_iommu_mm_set(container);
354 if (ret)
355 return ret;
356
357 locked = table_group->tce32_size >> PAGE_SHIFT;
358 ret = try_increment_locked_vm(container->mm, locked);
359 if (ret)
360 return ret;
361
362 container->locked_pages = locked;
363
364 container->enabled = true;
365
366 return ret;
367 }
368
369 static void tce_iommu_disable(struct tce_container *container)
370 {
371 if (!container->enabled)
372 return;
373
374 container->enabled = false;
375
376 BUG_ON(!container->mm);
377 decrement_locked_vm(container->mm, container->locked_pages);
378 }
379
380 static void *tce_iommu_open(unsigned long arg)
381 {
382 struct tce_container *container;
383
384 if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
385 pr_err("tce_vfio: Wrong IOMMU type\n");
386 return ERR_PTR(-EINVAL);
387 }
388
389 container = kzalloc(sizeof(*container), GFP_KERNEL);
390 if (!container)
391 return ERR_PTR(-ENOMEM);
392
393 mutex_init(&container->lock);
394 INIT_LIST_HEAD_RCU(&container->group_list);
395 INIT_LIST_HEAD_RCU(&container->prereg_list);
396
397 container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
398
399 return container;
400 }
401
402 static int tce_iommu_clear(struct tce_container *container,
403 struct iommu_table *tbl,
404 unsigned long entry, unsigned long pages);
405 static void tce_iommu_free_table(struct tce_container *container,
406 struct iommu_table *tbl);
407
408 static void tce_iommu_release(void *iommu_data)
409 {
410 struct tce_container *container = iommu_data;
411 struct tce_iommu_group *tcegrp;
412 long i;
413
414 while (tce_groups_attached(container)) {
415 tcegrp = list_first_entry(&container->group_list,
416 struct tce_iommu_group, next);
417 tce_iommu_detach_group(iommu_data, tcegrp->grp);
418 }
419
420 /*
421 * If VFIO created a table, it was not disposed
422 * by tce_iommu_detach_group() so do it now.
423 */
424 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
425 struct iommu_table *tbl = container->tables[i];
426
427 if (!tbl)
428 continue;
429
430 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
431 tce_iommu_free_table(container, tbl);
432 }
433
434 while (!list_empty(&container->prereg_list)) {
435 struct tce_iommu_prereg *tcemem;
436
437 tcemem = list_first_entry(&container->prereg_list,
438 struct tce_iommu_prereg, next);
439 WARN_ON_ONCE(tce_iommu_prereg_free(container, tcemem));
440 }
441
442 tce_iommu_disable(container);
443 if (container->mm)
444 mmdrop(container->mm);
445 mutex_destroy(&container->lock);
446
447 kfree(container);
448 }
449
450 static void tce_iommu_unuse_page(struct tce_container *container,
451 unsigned long hpa)
452 {
453 struct page *page;
454
455 page = pfn_to_page(hpa >> PAGE_SHIFT);
456 put_page(page);
457 }
458
459 static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
460 unsigned long tce, unsigned long size,
461 unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
462 {
463 long ret = 0;
464 struct mm_iommu_table_group_mem_t *mem;
465
466 mem = mm_iommu_lookup(container->mm, tce, size);
467 if (!mem)
468 return -EINVAL;
469
470 ret = mm_iommu_ua_to_hpa(mem, tce, phpa);
471 if (ret)
472 return -EINVAL;
473
474 *pmem = mem;
475
476 return 0;
477 }
478
479 static void tce_iommu_unuse_page_v2(struct tce_container *container,
480 struct iommu_table *tbl, unsigned long entry)
481 {
482 struct mm_iommu_table_group_mem_t *mem = NULL;
483 int ret;
484 unsigned long hpa = 0;
485 unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry);
486
487 if (!pua)
488 return;
489
490 ret = tce_iommu_prereg_ua_to_hpa(container, *pua, IOMMU_PAGE_SIZE(tbl),
491 &hpa, &mem);
492 if (ret)
493 pr_debug("%s: tce %lx at #%lx was not cached, ret=%d\n",
494 __func__, *pua, entry, ret);
495 if (mem)
496 mm_iommu_mapped_dec(mem);
497
498 *pua = 0;
499 }
500
501 static int tce_iommu_clear(struct tce_container *container,
502 struct iommu_table *tbl,
503 unsigned long entry, unsigned long pages)
504 {
505 unsigned long oldhpa;
506 long ret;
507 enum dma_data_direction direction;
508
509 for ( ; pages; --pages, ++entry) {
510 cond_resched();
511
512 direction = DMA_NONE;
513 oldhpa = 0;
514 ret = iommu_tce_xchg(tbl, entry, &oldhpa, &direction);
515 if (ret)
516 continue;
517
518 if (direction == DMA_NONE)
519 continue;
520
521 if (container->v2) {
522 tce_iommu_unuse_page_v2(container, tbl, entry);
523 continue;
524 }
525
526 tce_iommu_unuse_page(container, oldhpa);
527 }
528
529 return 0;
530 }
531
532 static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
533 {
534 struct page *page = NULL;
535 enum dma_data_direction direction = iommu_tce_direction(tce);
536
537 if (get_user_pages_fast(tce & PAGE_MASK, 1,
538 direction != DMA_TO_DEVICE, &page) != 1)
539 return -EFAULT;
540
541 *hpa = __pa((unsigned long) page_address(page));
542
543 return 0;
544 }
545
546 static long tce_iommu_build(struct tce_container *container,
547 struct iommu_table *tbl,
548 unsigned long entry, unsigned long tce, unsigned long pages,
549 enum dma_data_direction direction)
550 {
551 long i, ret = 0;
552 struct page *page;
553 unsigned long hpa;
554 enum dma_data_direction dirtmp;
555
556 for (i = 0; i < pages; ++i) {
557 unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
558
559 ret = tce_iommu_use_page(tce, &hpa);
560 if (ret)
561 break;
562
563 page = pfn_to_page(hpa >> PAGE_SHIFT);
564 if (!tce_page_is_contained(page, tbl->it_page_shift)) {
565 ret = -EPERM;
566 break;
567 }
568
569 hpa |= offset;
570 dirtmp = direction;
571 ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp);
572 if (ret) {
573 tce_iommu_unuse_page(container, hpa);
574 pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
575 __func__, entry << tbl->it_page_shift,
576 tce, ret);
577 break;
578 }
579
580 if (dirtmp != DMA_NONE)
581 tce_iommu_unuse_page(container, hpa);
582
583 tce += IOMMU_PAGE_SIZE(tbl);
584 }
585
586 if (ret)
587 tce_iommu_clear(container, tbl, entry, i);
588
589 return ret;
590 }
591
592 static long tce_iommu_build_v2(struct tce_container *container,
593 struct iommu_table *tbl,
594 unsigned long entry, unsigned long tce, unsigned long pages,
595 enum dma_data_direction direction)
596 {
597 long i, ret = 0;
598 struct page *page;
599 unsigned long hpa;
600 enum dma_data_direction dirtmp;
601
602 if (!tbl->it_userspace) {
603 ret = tce_iommu_userspace_view_alloc(tbl, container->mm);
604 if (ret)
605 return ret;
606 }
607
608 for (i = 0; i < pages; ++i) {
609 struct mm_iommu_table_group_mem_t *mem = NULL;
610 unsigned long *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl,
611 entry + i);
612
613 ret = tce_iommu_prereg_ua_to_hpa(container,
614 tce, IOMMU_PAGE_SIZE(tbl), &hpa, &mem);
615 if (ret)
616 break;
617
618 page = pfn_to_page(hpa >> PAGE_SHIFT);
619 if (!tce_page_is_contained(page, tbl->it_page_shift)) {
620 ret = -EPERM;
621 break;
622 }
623
624 /* Preserve offset within IOMMU page */
625 hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
626 dirtmp = direction;
627
628 /* The registered region is being unregistered */
629 if (mm_iommu_mapped_inc(mem))
630 break;
631
632 ret = iommu_tce_xchg(tbl, entry + i, &hpa, &dirtmp);
633 if (ret) {
634 /* dirtmp cannot be DMA_NONE here */
635 tce_iommu_unuse_page_v2(container, tbl, entry + i);
636 pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
637 __func__, entry << tbl->it_page_shift,
638 tce, ret);
639 break;
640 }
641
642 if (dirtmp != DMA_NONE)
643 tce_iommu_unuse_page_v2(container, tbl, entry + i);
644
645 *pua = tce;
646
647 tce += IOMMU_PAGE_SIZE(tbl);
648 }
649
650 if (ret)
651 tce_iommu_clear(container, tbl, entry, i);
652
653 return ret;
654 }
655
656 static long tce_iommu_create_table(struct tce_container *container,
657 struct iommu_table_group *table_group,
658 int num,
659 __u32 page_shift,
660 __u64 window_size,
661 __u32 levels,
662 struct iommu_table **ptbl)
663 {
664 long ret, table_size;
665
666 table_size = table_group->ops->get_table_size(page_shift, window_size,
667 levels);
668 if (!table_size)
669 return -EINVAL;
670
671 ret = try_increment_locked_vm(container->mm, table_size >> PAGE_SHIFT);
672 if (ret)
673 return ret;
674
675 ret = table_group->ops->create_table(table_group, num,
676 page_shift, window_size, levels, ptbl);
677
678 WARN_ON(!ret && !(*ptbl)->it_ops->free);
679 WARN_ON(!ret && ((*ptbl)->it_allocated_size != table_size));
680
681 return ret;
682 }
683
684 static void tce_iommu_free_table(struct tce_container *container,
685 struct iommu_table *tbl)
686 {
687 unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
688
689 tce_iommu_userspace_view_free(tbl, container->mm);
690 iommu_tce_table_put(tbl);
691 decrement_locked_vm(container->mm, pages);
692 }
693
694 static long tce_iommu_create_window(struct tce_container *container,
695 __u32 page_shift, __u64 window_size, __u32 levels,
696 __u64 *start_addr)
697 {
698 struct tce_iommu_group *tcegrp;
699 struct iommu_table_group *table_group;
700 struct iommu_table *tbl = NULL;
701 long ret, num;
702
703 num = tce_iommu_find_free_table(container);
704 if (num < 0)
705 return num;
706
707 /* Get the first group for ops::create_table */
708 tcegrp = list_first_entry(&container->group_list,
709 struct tce_iommu_group, next);
710 table_group = iommu_group_get_iommudata(tcegrp->grp);
711 if (!table_group)
712 return -EFAULT;
713
714 if (!(table_group->pgsizes & (1ULL << page_shift)))
715 return -EINVAL;
716
717 if (!table_group->ops->set_window || !table_group->ops->unset_window ||
718 !table_group->ops->get_table_size ||
719 !table_group->ops->create_table)
720 return -EPERM;
721
722 /* Create TCE table */
723 ret = tce_iommu_create_table(container, table_group, num,
724 page_shift, window_size, levels, &tbl);
725 if (ret)
726 return ret;
727
728 BUG_ON(!tbl->it_ops->free);
729
730 /*
731 * Program the table to every group.
732 * Groups have been tested for compatibility at the attach time.
733 */
734 list_for_each_entry(tcegrp, &container->group_list, next) {
735 table_group = iommu_group_get_iommudata(tcegrp->grp);
736
737 ret = table_group->ops->set_window(table_group, num, tbl);
738 if (ret)
739 goto unset_exit;
740 }
741
742 container->tables[num] = tbl;
743
744 /* Return start address assigned by platform in create_table() */
745 *start_addr = tbl->it_offset << tbl->it_page_shift;
746
747 return 0;
748
749 unset_exit:
750 list_for_each_entry(tcegrp, &container->group_list, next) {
751 table_group = iommu_group_get_iommudata(tcegrp->grp);
752 table_group->ops->unset_window(table_group, num);
753 }
754 tce_iommu_free_table(container, tbl);
755
756 return ret;
757 }
758
759 static long tce_iommu_remove_window(struct tce_container *container,
760 __u64 start_addr)
761 {
762 struct iommu_table_group *table_group = NULL;
763 struct iommu_table *tbl;
764 struct tce_iommu_group *tcegrp;
765 int num;
766
767 num = tce_iommu_find_table(container, start_addr, &tbl);
768 if (num < 0)
769 return -EINVAL;
770
771 BUG_ON(!tbl->it_size);
772
773 /* Detach groups from IOMMUs */
774 list_for_each_entry(tcegrp, &container->group_list, next) {
775 table_group = iommu_group_get_iommudata(tcegrp->grp);
776
777 /*
778 * SPAPR TCE IOMMU exposes the default DMA window to
779 * the guest via dma32_window_start/size of
780 * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
781 * the userspace to remove this window, some do not so
782 * here we check for the platform capability.
783 */
784 if (!table_group->ops || !table_group->ops->unset_window)
785 return -EPERM;
786
787 table_group->ops->unset_window(table_group, num);
788 }
789
790 /* Free table */
791 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
792 tce_iommu_free_table(container, tbl);
793 container->tables[num] = NULL;
794
795 return 0;
796 }
797
798 static long tce_iommu_create_default_window(struct tce_container *container)
799 {
800 long ret;
801 __u64 start_addr = 0;
802 struct tce_iommu_group *tcegrp;
803 struct iommu_table_group *table_group;
804
805 if (!container->def_window_pending)
806 return 0;
807
808 if (!tce_groups_attached(container))
809 return -ENODEV;
810
811 tcegrp = list_first_entry(&container->group_list,
812 struct tce_iommu_group, next);
813 table_group = iommu_group_get_iommudata(tcegrp->grp);
814 if (!table_group)
815 return -ENODEV;
816
817 ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
818 table_group->tce32_size, 1, &start_addr);
819 WARN_ON_ONCE(!ret && start_addr);
820
821 if (!ret)
822 container->def_window_pending = false;
823
824 return ret;
825 }
826
827 static long tce_iommu_ioctl(void *iommu_data,
828 unsigned int cmd, unsigned long arg)
829 {
830 struct tce_container *container = iommu_data;
831 unsigned long minsz, ddwsz;
832 long ret;
833
834 switch (cmd) {
835 case VFIO_CHECK_EXTENSION:
836 switch (arg) {
837 case VFIO_SPAPR_TCE_IOMMU:
838 case VFIO_SPAPR_TCE_v2_IOMMU:
839 ret = 1;
840 break;
841 default:
842 ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
843 break;
844 }
845
846 return (ret < 0) ? 0 : ret;
847 }
848
849 /*
850 * Sanity check to prevent one userspace from manipulating
851 * another userspace mm.
852 */
853 BUG_ON(!container);
854 if (container->mm && container->mm != current->mm)
855 return -EPERM;
856
857 switch (cmd) {
858 case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
859 struct vfio_iommu_spapr_tce_info info;
860 struct tce_iommu_group *tcegrp;
861 struct iommu_table_group *table_group;
862
863 if (!tce_groups_attached(container))
864 return -ENXIO;
865
866 tcegrp = list_first_entry(&container->group_list,
867 struct tce_iommu_group, next);
868 table_group = iommu_group_get_iommudata(tcegrp->grp);
869
870 if (!table_group)
871 return -ENXIO;
872
873 minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
874 dma32_window_size);
875
876 if (copy_from_user(&info, (void __user *)arg, minsz))
877 return -EFAULT;
878
879 if (info.argsz < minsz)
880 return -EINVAL;
881
882 info.dma32_window_start = table_group->tce32_start;
883 info.dma32_window_size = table_group->tce32_size;
884 info.flags = 0;
885 memset(&info.ddw, 0, sizeof(info.ddw));
886
887 if (table_group->max_dynamic_windows_supported &&
888 container->v2) {
889 info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
890 info.ddw.pgsizes = table_group->pgsizes;
891 info.ddw.max_dynamic_windows_supported =
892 table_group->max_dynamic_windows_supported;
893 info.ddw.levels = table_group->max_levels;
894 }
895
896 ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
897
898 if (info.argsz >= ddwsz)
899 minsz = ddwsz;
900
901 if (copy_to_user((void __user *)arg, &info, minsz))
902 return -EFAULT;
903
904 return 0;
905 }
906 case VFIO_IOMMU_MAP_DMA: {
907 struct vfio_iommu_type1_dma_map param;
908 struct iommu_table *tbl = NULL;
909 long num;
910 enum dma_data_direction direction;
911
912 if (!container->enabled)
913 return -EPERM;
914
915 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
916
917 if (copy_from_user(&param, (void __user *)arg, minsz))
918 return -EFAULT;
919
920 if (param.argsz < minsz)
921 return -EINVAL;
922
923 if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
924 VFIO_DMA_MAP_FLAG_WRITE))
925 return -EINVAL;
926
927 ret = tce_iommu_create_default_window(container);
928 if (ret)
929 return ret;
930
931 num = tce_iommu_find_table(container, param.iova, &tbl);
932 if (num < 0)
933 return -ENXIO;
934
935 if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
936 (param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
937 return -EINVAL;
938
939 /* iova is checked by the IOMMU API */
940 if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
941 if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
942 direction = DMA_BIDIRECTIONAL;
943 else
944 direction = DMA_TO_DEVICE;
945 } else {
946 if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
947 direction = DMA_FROM_DEVICE;
948 else
949 return -EINVAL;
950 }
951
952 ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
953 if (ret)
954 return ret;
955
956 if (container->v2)
957 ret = tce_iommu_build_v2(container, tbl,
958 param.iova >> tbl->it_page_shift,
959 param.vaddr,
960 param.size >> tbl->it_page_shift,
961 direction);
962 else
963 ret = tce_iommu_build(container, tbl,
964 param.iova >> tbl->it_page_shift,
965 param.vaddr,
966 param.size >> tbl->it_page_shift,
967 direction);
968
969 iommu_flush_tce(tbl);
970
971 return ret;
972 }
973 case VFIO_IOMMU_UNMAP_DMA: {
974 struct vfio_iommu_type1_dma_unmap param;
975 struct iommu_table *tbl = NULL;
976 long num;
977
978 if (!container->enabled)
979 return -EPERM;
980
981 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
982 size);
983
984 if (copy_from_user(&param, (void __user *)arg, minsz))
985 return -EFAULT;
986
987 if (param.argsz < minsz)
988 return -EINVAL;
989
990 /* No flag is supported now */
991 if (param.flags)
992 return -EINVAL;
993
994 ret = tce_iommu_create_default_window(container);
995 if (ret)
996 return ret;
997
998 num = tce_iommu_find_table(container, param.iova, &tbl);
999 if (num < 0)
1000 return -ENXIO;
1001
1002 if (param.size & ~IOMMU_PAGE_MASK(tbl))
1003 return -EINVAL;
1004
1005 ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
1006 param.size >> tbl->it_page_shift);
1007 if (ret)
1008 return ret;
1009
1010 ret = tce_iommu_clear(container, tbl,
1011 param.iova >> tbl->it_page_shift,
1012 param.size >> tbl->it_page_shift);
1013 iommu_flush_tce(tbl);
1014
1015 return ret;
1016 }
1017 case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
1018 struct vfio_iommu_spapr_register_memory param;
1019
1020 if (!container->v2)
1021 break;
1022
1023 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1024 size);
1025
1026 ret = tce_iommu_mm_set(container);
1027 if (ret)
1028 return ret;
1029
1030 if (copy_from_user(&param, (void __user *)arg, minsz))
1031 return -EFAULT;
1032
1033 if (param.argsz < minsz)
1034 return -EINVAL;
1035
1036 /* No flag is supported now */
1037 if (param.flags)
1038 return -EINVAL;
1039
1040 mutex_lock(&container->lock);
1041 ret = tce_iommu_register_pages(container, param.vaddr,
1042 param.size);
1043 mutex_unlock(&container->lock);
1044
1045 return ret;
1046 }
1047 case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
1048 struct vfio_iommu_spapr_register_memory param;
1049
1050 if (!container->v2)
1051 break;
1052
1053 if (!container->mm)
1054 return -EPERM;
1055
1056 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1057 size);
1058
1059 if (copy_from_user(&param, (void __user *)arg, minsz))
1060 return -EFAULT;
1061
1062 if (param.argsz < minsz)
1063 return -EINVAL;
1064
1065 /* No flag is supported now */
1066 if (param.flags)
1067 return -EINVAL;
1068
1069 mutex_lock(&container->lock);
1070 ret = tce_iommu_unregister_pages(container, param.vaddr,
1071 param.size);
1072 mutex_unlock(&container->lock);
1073
1074 return ret;
1075 }
1076 case VFIO_IOMMU_ENABLE:
1077 if (container->v2)
1078 break;
1079
1080 mutex_lock(&container->lock);
1081 ret = tce_iommu_enable(container);
1082 mutex_unlock(&container->lock);
1083 return ret;
1084
1085
1086 case VFIO_IOMMU_DISABLE:
1087 if (container->v2)
1088 break;
1089
1090 mutex_lock(&container->lock);
1091 tce_iommu_disable(container);
1092 mutex_unlock(&container->lock);
1093 return 0;
1094
1095 case VFIO_EEH_PE_OP: {
1096 struct tce_iommu_group *tcegrp;
1097
1098 ret = 0;
1099 list_for_each_entry(tcegrp, &container->group_list, next) {
1100 ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
1101 cmd, arg);
1102 if (ret)
1103 return ret;
1104 }
1105 return ret;
1106 }
1107
1108 case VFIO_IOMMU_SPAPR_TCE_CREATE: {
1109 struct vfio_iommu_spapr_tce_create create;
1110
1111 if (!container->v2)
1112 break;
1113
1114 ret = tce_iommu_mm_set(container);
1115 if (ret)
1116 return ret;
1117
1118 if (!tce_groups_attached(container))
1119 return -ENXIO;
1120
1121 minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
1122 start_addr);
1123
1124 if (copy_from_user(&create, (void __user *)arg, minsz))
1125 return -EFAULT;
1126
1127 if (create.argsz < minsz)
1128 return -EINVAL;
1129
1130 if (create.flags)
1131 return -EINVAL;
1132
1133 mutex_lock(&container->lock);
1134
1135 ret = tce_iommu_create_default_window(container);
1136 if (!ret)
1137 ret = tce_iommu_create_window(container,
1138 create.page_shift,
1139 create.window_size, create.levels,
1140 &create.start_addr);
1141
1142 mutex_unlock(&container->lock);
1143
1144 if (!ret && copy_to_user((void __user *)arg, &create, minsz))
1145 ret = -EFAULT;
1146
1147 return ret;
1148 }
1149 case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
1150 struct vfio_iommu_spapr_tce_remove remove;
1151
1152 if (!container->v2)
1153 break;
1154
1155 ret = tce_iommu_mm_set(container);
1156 if (ret)
1157 return ret;
1158
1159 if (!tce_groups_attached(container))
1160 return -ENXIO;
1161
1162 minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
1163 start_addr);
1164
1165 if (copy_from_user(&remove, (void __user *)arg, minsz))
1166 return -EFAULT;
1167
1168 if (remove.argsz < minsz)
1169 return -EINVAL;
1170
1171 if (remove.flags)
1172 return -EINVAL;
1173
1174 if (container->def_window_pending && !remove.start_addr) {
1175 container->def_window_pending = false;
1176 return 0;
1177 }
1178
1179 mutex_lock(&container->lock);
1180
1181 ret = tce_iommu_remove_window(container, remove.start_addr);
1182
1183 mutex_unlock(&container->lock);
1184
1185 return ret;
1186 }
1187 }
1188
1189 return -ENOTTY;
1190 }
1191
1192 static void tce_iommu_release_ownership(struct tce_container *container,
1193 struct iommu_table_group *table_group)
1194 {
1195 int i;
1196
1197 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1198 struct iommu_table *tbl = container->tables[i];
1199
1200 if (!tbl)
1201 continue;
1202
1203 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
1204 tce_iommu_userspace_view_free(tbl, container->mm);
1205 if (tbl->it_map)
1206 iommu_release_ownership(tbl);
1207
1208 container->tables[i] = NULL;
1209 }
1210 }
1211
1212 static int tce_iommu_take_ownership(struct tce_container *container,
1213 struct iommu_table_group *table_group)
1214 {
1215 int i, j, rc = 0;
1216
1217 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1218 struct iommu_table *tbl = table_group->tables[i];
1219
1220 if (!tbl || !tbl->it_map)
1221 continue;
1222
1223 rc = iommu_take_ownership(tbl);
1224 if (rc) {
1225 for (j = 0; j < i; ++j)
1226 iommu_release_ownership(
1227 table_group->tables[j]);
1228
1229 return rc;
1230 }
1231 }
1232
1233 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1234 container->tables[i] = table_group->tables[i];
1235
1236 return 0;
1237 }
1238
1239 static void tce_iommu_release_ownership_ddw(struct tce_container *container,
1240 struct iommu_table_group *table_group)
1241 {
1242 long i;
1243
1244 if (!table_group->ops->unset_window) {
1245 WARN_ON_ONCE(1);
1246 return;
1247 }
1248
1249 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1250 table_group->ops->unset_window(table_group, i);
1251
1252 table_group->ops->release_ownership(table_group);
1253 }
1254
1255 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
1256 struct iommu_table_group *table_group)
1257 {
1258 long i, ret = 0;
1259
1260 if (!table_group->ops->create_table || !table_group->ops->set_window ||
1261 !table_group->ops->release_ownership) {
1262 WARN_ON_ONCE(1);
1263 return -EFAULT;
1264 }
1265
1266 table_group->ops->take_ownership(table_group);
1267
1268 /* Set all windows to the new group */
1269 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1270 struct iommu_table *tbl = container->tables[i];
1271
1272 if (!tbl)
1273 continue;
1274
1275 ret = table_group->ops->set_window(table_group, i, tbl);
1276 if (ret)
1277 goto release_exit;
1278 }
1279
1280 return 0;
1281
1282 release_exit:
1283 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1284 table_group->ops->unset_window(table_group, i);
1285
1286 table_group->ops->release_ownership(table_group);
1287
1288 return ret;
1289 }
1290
1291 static int tce_iommu_attach_group(void *iommu_data,
1292 struct iommu_group *iommu_group)
1293 {
1294 int ret;
1295 struct tce_container *container = iommu_data;
1296 struct iommu_table_group *table_group;
1297 struct tce_iommu_group *tcegrp = NULL;
1298
1299 mutex_lock(&container->lock);
1300
1301 /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
1302 iommu_group_id(iommu_group), iommu_group); */
1303 table_group = iommu_group_get_iommudata(iommu_group);
1304 if (!table_group) {
1305 ret = -ENODEV;
1306 goto unlock_exit;
1307 }
1308
1309 if (tce_groups_attached(container) && (!table_group->ops ||
1310 !table_group->ops->take_ownership ||
1311 !table_group->ops->release_ownership)) {
1312 ret = -EBUSY;
1313 goto unlock_exit;
1314 }
1315
1316 /* Check if new group has the same iommu_ops (i.e. compatible) */
1317 list_for_each_entry(tcegrp, &container->group_list, next) {
1318 struct iommu_table_group *table_group_tmp;
1319
1320 if (tcegrp->grp == iommu_group) {
1321 pr_warn("tce_vfio: Group %d is already attached\n",
1322 iommu_group_id(iommu_group));
1323 ret = -EBUSY;
1324 goto unlock_exit;
1325 }
1326 table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
1327 if (table_group_tmp->ops->create_table !=
1328 table_group->ops->create_table) {
1329 pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
1330 iommu_group_id(iommu_group),
1331 iommu_group_id(tcegrp->grp));
1332 ret = -EPERM;
1333 goto unlock_exit;
1334 }
1335 }
1336
1337 tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
1338 if (!tcegrp) {
1339 ret = -ENOMEM;
1340 goto unlock_exit;
1341 }
1342
1343 if (!table_group->ops || !table_group->ops->take_ownership ||
1344 !table_group->ops->release_ownership) {
1345 if (container->v2) {
1346 ret = -EPERM;
1347 goto unlock_exit;
1348 }
1349 ret = tce_iommu_take_ownership(container, table_group);
1350 } else {
1351 if (!container->v2) {
1352 ret = -EPERM;
1353 goto unlock_exit;
1354 }
1355 ret = tce_iommu_take_ownership_ddw(container, table_group);
1356 if (!tce_groups_attached(container) && !container->tables[0])
1357 container->def_window_pending = true;
1358 }
1359
1360 if (!ret) {
1361 tcegrp->grp = iommu_group;
1362 list_add(&tcegrp->next, &container->group_list);
1363 }
1364
1365 unlock_exit:
1366 if (ret && tcegrp)
1367 kfree(tcegrp);
1368
1369 mutex_unlock(&container->lock);
1370
1371 return ret;
1372 }
1373
1374 static void tce_iommu_detach_group(void *iommu_data,
1375 struct iommu_group *iommu_group)
1376 {
1377 struct tce_container *container = iommu_data;
1378 struct iommu_table_group *table_group;
1379 bool found = false;
1380 struct tce_iommu_group *tcegrp;
1381
1382 mutex_lock(&container->lock);
1383
1384 list_for_each_entry(tcegrp, &container->group_list, next) {
1385 if (tcegrp->grp == iommu_group) {
1386 found = true;
1387 break;
1388 }
1389 }
1390
1391 if (!found) {
1392 pr_warn("tce_vfio: detaching unattached group #%u\n",
1393 iommu_group_id(iommu_group));
1394 goto unlock_exit;
1395 }
1396
1397 list_del(&tcegrp->next);
1398 kfree(tcegrp);
1399
1400 table_group = iommu_group_get_iommudata(iommu_group);
1401 BUG_ON(!table_group);
1402
1403 if (!table_group->ops || !table_group->ops->release_ownership)
1404 tce_iommu_release_ownership(container, table_group);
1405 else
1406 tce_iommu_release_ownership_ddw(container, table_group);
1407
1408 unlock_exit:
1409 mutex_unlock(&container->lock);
1410 }
1411
1412 const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
1413 .name = "iommu-vfio-powerpc",
1414 .owner = THIS_MODULE,
1415 .open = tce_iommu_open,
1416 .release = tce_iommu_release,
1417 .ioctl = tce_iommu_ioctl,
1418 .attach_group = tce_iommu_attach_group,
1419 .detach_group = tce_iommu_detach_group,
1420 };
1421
1422 static int __init tce_iommu_init(void)
1423 {
1424 return vfio_register_iommu_driver(&tce_iommu_driver_ops);
1425 }
1426
1427 static void __exit tce_iommu_cleanup(void)
1428 {
1429 vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
1430 }
1431
1432 module_init(tce_iommu_init);
1433 module_exit(tce_iommu_cleanup);
1434
1435 MODULE_VERSION(DRIVER_VERSION);
1436 MODULE_LICENSE("GPL v2");
1437 MODULE_AUTHOR(DRIVER_AUTHOR);
1438 MODULE_DESCRIPTION(DRIVER_DESC);
1439
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