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Merge tag 'for-rc-adfs' of git://git.armlinux.org.uk/~rmk/linux-arm
[mirror_ubuntu-hirsute-kernel.git] / drivers / vfio / vfio_iommu_spapr_tce.c
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 long ret;
156
157 if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
158 return -EINVAL;
159
160 mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT);
161 if (!mem)
162 return -ENOENT;
163
164 list_for_each_entry(tcemem, &container->prereg_list, next) {
165 if (tcemem->mem == mem) {
166 found = true;
167 break;
168 }
169 }
170
171 if (!found)
172 ret = -ENOENT;
173 else
174 ret = tce_iommu_prereg_free(container, tcemem);
175
176 mm_iommu_put(container->mm, mem);
177
178 return ret;
179 }
180
181 static long tce_iommu_register_pages(struct tce_container *container,
182 __u64 vaddr, __u64 size)
183 {
184 long ret = 0;
185 struct mm_iommu_table_group_mem_t *mem = NULL;
186 struct tce_iommu_prereg *tcemem;
187 unsigned long entries = size >> PAGE_SHIFT;
188
189 if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
190 ((vaddr + size) < vaddr))
191 return -EINVAL;
192
193 mem = mm_iommu_get(container->mm, vaddr, entries);
194 if (mem) {
195 list_for_each_entry(tcemem, &container->prereg_list, next) {
196 if (tcemem->mem == mem) {
197 ret = -EBUSY;
198 goto put_exit;
199 }
200 }
201 } else {
202 ret = mm_iommu_new(container->mm, vaddr, entries, &mem);
203 if (ret)
204 return ret;
205 }
206
207 tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
208 if (!tcemem) {
209 ret = -ENOMEM;
210 goto put_exit;
211 }
212
213 tcemem->mem = mem;
214 list_add(&tcemem->next, &container->prereg_list);
215
216 container->enabled = true;
217
218 return 0;
219
220 put_exit:
221 mm_iommu_put(container->mm, mem);
222 return ret;
223 }
224
225 static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
226 unsigned int page_shift)
227 {
228 struct page *page;
229 unsigned long size = 0;
230
231 if (mm_iommu_is_devmem(mm, hpa, page_shift, &size))
232 return size == (1UL << page_shift);
233
234 page = pfn_to_page(hpa >> PAGE_SHIFT);
235 /*
236 * Check that the TCE table granularity is not bigger than the size of
237 * a page we just found. Otherwise the hardware can get access to
238 * a bigger memory chunk that it should.
239 */
240 return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
241 }
242
243 static inline bool tce_groups_attached(struct tce_container *container)
244 {
245 return !list_empty(&container->group_list);
246 }
247
248 static long tce_iommu_find_table(struct tce_container *container,
249 phys_addr_t ioba, struct iommu_table **ptbl)
250 {
251 long i;
252
253 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
254 struct iommu_table *tbl = container->tables[i];
255
256 if (tbl) {
257 unsigned long entry = ioba >> tbl->it_page_shift;
258 unsigned long start = tbl->it_offset;
259 unsigned long end = start + tbl->it_size;
260
261 if ((start <= entry) && (entry < end)) {
262 *ptbl = tbl;
263 return i;
264 }
265 }
266 }
267
268 return -1;
269 }
270
271 static int tce_iommu_find_free_table(struct tce_container *container)
272 {
273 int i;
274
275 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
276 if (!container->tables[i])
277 return i;
278 }
279
280 return -ENOSPC;
281 }
282
283 static int tce_iommu_enable(struct tce_container *container)
284 {
285 int ret = 0;
286 unsigned long locked;
287 struct iommu_table_group *table_group;
288 struct tce_iommu_group *tcegrp;
289
290 if (container->enabled)
291 return -EBUSY;
292
293 /*
294 * When userspace pages are mapped into the IOMMU, they are effectively
295 * locked memory, so, theoretically, we need to update the accounting
296 * of locked pages on each map and unmap. For powerpc, the map unmap
297 * paths can be very hot, though, and the accounting would kill
298 * performance, especially since it would be difficult to impossible
299 * to handle the accounting in real mode only.
300 *
301 * To address that, rather than precisely accounting every page, we
302 * instead account for a worst case on locked memory when the iommu is
303 * enabled and disabled. The worst case upper bound on locked memory
304 * is the size of the whole iommu window, which is usually relatively
305 * small (compared to total memory sizes) on POWER hardware.
306 *
307 * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
308 * that would effectively kill the guest at random points, much better
309 * enforcing the limit based on the max that the guest can map.
310 *
311 * Unfortunately at the moment it counts whole tables, no matter how
312 * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
313 * each with 2GB DMA window, 8GB will be counted here. The reason for
314 * this is that we cannot tell here the amount of RAM used by the guest
315 * as this information is only available from KVM and VFIO is
316 * KVM agnostic.
317 *
318 * So we do not allow enabling a container without a group attached
319 * as there is no way to know how much we should increment
320 * the locked_vm counter.
321 */
322 if (!tce_groups_attached(container))
323 return -ENODEV;
324
325 tcegrp = list_first_entry(&container->group_list,
326 struct tce_iommu_group, next);
327 table_group = iommu_group_get_iommudata(tcegrp->grp);
328 if (!table_group)
329 return -ENODEV;
330
331 if (!table_group->tce32_size)
332 return -EPERM;
333
334 ret = tce_iommu_mm_set(container);
335 if (ret)
336 return ret;
337
338 locked = table_group->tce32_size >> PAGE_SHIFT;
339 ret = try_increment_locked_vm(container->mm, locked);
340 if (ret)
341 return ret;
342
343 container->locked_pages = locked;
344
345 container->enabled = true;
346
347 return ret;
348 }
349
350 static void tce_iommu_disable(struct tce_container *container)
351 {
352 if (!container->enabled)
353 return;
354
355 container->enabled = false;
356
357 BUG_ON(!container->mm);
358 decrement_locked_vm(container->mm, container->locked_pages);
359 }
360
361 static void *tce_iommu_open(unsigned long arg)
362 {
363 struct tce_container *container;
364
365 if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
366 pr_err("tce_vfio: Wrong IOMMU type\n");
367 return ERR_PTR(-EINVAL);
368 }
369
370 container = kzalloc(sizeof(*container), GFP_KERNEL);
371 if (!container)
372 return ERR_PTR(-ENOMEM);
373
374 mutex_init(&container->lock);
375 INIT_LIST_HEAD_RCU(&container->group_list);
376 INIT_LIST_HEAD_RCU(&container->prereg_list);
377
378 container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
379
380 return container;
381 }
382
383 static int tce_iommu_clear(struct tce_container *container,
384 struct iommu_table *tbl,
385 unsigned long entry, unsigned long pages);
386 static void tce_iommu_free_table(struct tce_container *container,
387 struct iommu_table *tbl);
388
389 static void tce_iommu_release(void *iommu_data)
390 {
391 struct tce_container *container = iommu_data;
392 struct tce_iommu_group *tcegrp;
393 struct tce_iommu_prereg *tcemem, *tmtmp;
394 long i;
395
396 while (tce_groups_attached(container)) {
397 tcegrp = list_first_entry(&container->group_list,
398 struct tce_iommu_group, next);
399 tce_iommu_detach_group(iommu_data, tcegrp->grp);
400 }
401
402 /*
403 * If VFIO created a table, it was not disposed
404 * by tce_iommu_detach_group() so do it now.
405 */
406 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
407 struct iommu_table *tbl = container->tables[i];
408
409 if (!tbl)
410 continue;
411
412 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
413 tce_iommu_free_table(container, tbl);
414 }
415
416 list_for_each_entry_safe(tcemem, tmtmp, &container->prereg_list, next)
417 WARN_ON(tce_iommu_prereg_free(container, tcemem));
418
419 tce_iommu_disable(container);
420 if (container->mm)
421 mmdrop(container->mm);
422 mutex_destroy(&container->lock);
423
424 kfree(container);
425 }
426
427 static void tce_iommu_unuse_page(struct tce_container *container,
428 unsigned long hpa)
429 {
430 struct page *page;
431
432 page = pfn_to_page(hpa >> PAGE_SHIFT);
433 put_page(page);
434 }
435
436 static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
437 unsigned long tce, unsigned long shift,
438 unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
439 {
440 long ret = 0;
441 struct mm_iommu_table_group_mem_t *mem;
442
443 mem = mm_iommu_lookup(container->mm, tce, 1ULL << shift);
444 if (!mem)
445 return -EINVAL;
446
447 ret = mm_iommu_ua_to_hpa(mem, tce, shift, phpa);
448 if (ret)
449 return -EINVAL;
450
451 *pmem = mem;
452
453 return 0;
454 }
455
456 static void tce_iommu_unuse_page_v2(struct tce_container *container,
457 struct iommu_table *tbl, unsigned long entry)
458 {
459 struct mm_iommu_table_group_mem_t *mem = NULL;
460 int ret;
461 unsigned long hpa = 0;
462 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
463
464 if (!pua)
465 return;
466
467 ret = tce_iommu_prereg_ua_to_hpa(container, be64_to_cpu(*pua),
468 tbl->it_page_shift, &hpa, &mem);
469 if (ret)
470 pr_debug("%s: tce %llx at #%lx was not cached, ret=%d\n",
471 __func__, be64_to_cpu(*pua), entry, ret);
472 if (mem)
473 mm_iommu_mapped_dec(mem);
474
475 *pua = cpu_to_be64(0);
476 }
477
478 static int tce_iommu_clear(struct tce_container *container,
479 struct iommu_table *tbl,
480 unsigned long entry, unsigned long pages)
481 {
482 unsigned long oldhpa;
483 long ret;
484 enum dma_data_direction direction;
485 unsigned long lastentry = entry + pages;
486
487 for ( ; entry < lastentry; ++entry) {
488 if (tbl->it_indirect_levels && tbl->it_userspace) {
489 /*
490 * For multilevel tables, we can take a shortcut here
491 * and skip some TCEs as we know that the userspace
492 * addresses cache is a mirror of the real TCE table
493 * and if it is missing some indirect levels, then
494 * the hardware table does not have them allocated
495 * either and therefore does not require updating.
496 */
497 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl,
498 entry);
499 if (!pua) {
500 /* align to level_size which is power of two */
501 entry |= tbl->it_level_size - 1;
502 continue;
503 }
504 }
505
506 cond_resched();
507
508 direction = DMA_NONE;
509 oldhpa = 0;
510 ret = iommu_tce_xchg(container->mm, tbl, entry, &oldhpa,
511 &direction);
512 if (ret)
513 continue;
514
515 if (direction == DMA_NONE)
516 continue;
517
518 if (container->v2) {
519 tce_iommu_unuse_page_v2(container, tbl, entry);
520 continue;
521 }
522
523 tce_iommu_unuse_page(container, oldhpa);
524 }
525
526 return 0;
527 }
528
529 static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
530 {
531 struct page *page = NULL;
532 enum dma_data_direction direction = iommu_tce_direction(tce);
533
534 if (get_user_pages_fast(tce & PAGE_MASK, 1,
535 direction != DMA_TO_DEVICE ? FOLL_WRITE : 0,
536 &page) != 1)
537 return -EFAULT;
538
539 *hpa = __pa((unsigned long) page_address(page));
540
541 return 0;
542 }
543
544 static long tce_iommu_build(struct tce_container *container,
545 struct iommu_table *tbl,
546 unsigned long entry, unsigned long tce, unsigned long pages,
547 enum dma_data_direction direction)
548 {
549 long i, ret = 0;
550 unsigned long hpa;
551 enum dma_data_direction dirtmp;
552
553 for (i = 0; i < pages; ++i) {
554 unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
555
556 ret = tce_iommu_use_page(tce, &hpa);
557 if (ret)
558 break;
559
560 if (!tce_page_is_contained(container->mm, hpa,
561 tbl->it_page_shift)) {
562 ret = -EPERM;
563 break;
564 }
565
566 hpa |= offset;
567 dirtmp = direction;
568 ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa,
569 &dirtmp);
570 if (ret) {
571 tce_iommu_unuse_page(container, hpa);
572 pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
573 __func__, entry << tbl->it_page_shift,
574 tce, ret);
575 break;
576 }
577
578 if (dirtmp != DMA_NONE)
579 tce_iommu_unuse_page(container, hpa);
580
581 tce += IOMMU_PAGE_SIZE(tbl);
582 }
583
584 if (ret)
585 tce_iommu_clear(container, tbl, entry, i);
586
587 return ret;
588 }
589
590 static long tce_iommu_build_v2(struct tce_container *container,
591 struct iommu_table *tbl,
592 unsigned long entry, unsigned long tce, unsigned long pages,
593 enum dma_data_direction direction)
594 {
595 long i, ret = 0;
596 unsigned long hpa;
597 enum dma_data_direction dirtmp;
598
599 for (i = 0; i < pages; ++i) {
600 struct mm_iommu_table_group_mem_t *mem = NULL;
601 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i);
602
603 ret = tce_iommu_prereg_ua_to_hpa(container,
604 tce, tbl->it_page_shift, &hpa, &mem);
605 if (ret)
606 break;
607
608 if (!tce_page_is_contained(container->mm, hpa,
609 tbl->it_page_shift)) {
610 ret = -EPERM;
611 break;
612 }
613
614 /* Preserve offset within IOMMU page */
615 hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
616 dirtmp = direction;
617
618 /* The registered region is being unregistered */
619 if (mm_iommu_mapped_inc(mem))
620 break;
621
622 ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa,
623 &dirtmp);
624 if (ret) {
625 /* dirtmp cannot be DMA_NONE here */
626 tce_iommu_unuse_page_v2(container, tbl, entry + i);
627 pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
628 __func__, entry << tbl->it_page_shift,
629 tce, ret);
630 break;
631 }
632
633 if (dirtmp != DMA_NONE)
634 tce_iommu_unuse_page_v2(container, tbl, entry + i);
635
636 *pua = cpu_to_be64(tce);
637
638 tce += IOMMU_PAGE_SIZE(tbl);
639 }
640
641 if (ret)
642 tce_iommu_clear(container, tbl, entry, i);
643
644 return ret;
645 }
646
647 static long tce_iommu_create_table(struct tce_container *container,
648 struct iommu_table_group *table_group,
649 int num,
650 __u32 page_shift,
651 __u64 window_size,
652 __u32 levels,
653 struct iommu_table **ptbl)
654 {
655 long ret, table_size;
656
657 table_size = table_group->ops->get_table_size(page_shift, window_size,
658 levels);
659 if (!table_size)
660 return -EINVAL;
661
662 ret = try_increment_locked_vm(container->mm, table_size >> PAGE_SHIFT);
663 if (ret)
664 return ret;
665
666 ret = table_group->ops->create_table(table_group, num,
667 page_shift, window_size, levels, ptbl);
668
669 WARN_ON(!ret && !(*ptbl)->it_ops->free);
670 WARN_ON(!ret && ((*ptbl)->it_allocated_size > table_size));
671
672 return ret;
673 }
674
675 static void tce_iommu_free_table(struct tce_container *container,
676 struct iommu_table *tbl)
677 {
678 unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
679
680 iommu_tce_table_put(tbl);
681 decrement_locked_vm(container->mm, pages);
682 }
683
684 static long tce_iommu_create_window(struct tce_container *container,
685 __u32 page_shift, __u64 window_size, __u32 levels,
686 __u64 *start_addr)
687 {
688 struct tce_iommu_group *tcegrp;
689 struct iommu_table_group *table_group;
690 struct iommu_table *tbl = NULL;
691 long ret, num;
692
693 num = tce_iommu_find_free_table(container);
694 if (num < 0)
695 return num;
696
697 /* Get the first group for ops::create_table */
698 tcegrp = list_first_entry(&container->group_list,
699 struct tce_iommu_group, next);
700 table_group = iommu_group_get_iommudata(tcegrp->grp);
701 if (!table_group)
702 return -EFAULT;
703
704 if (!(table_group->pgsizes & (1ULL << page_shift)))
705 return -EINVAL;
706
707 if (!table_group->ops->set_window || !table_group->ops->unset_window ||
708 !table_group->ops->get_table_size ||
709 !table_group->ops->create_table)
710 return -EPERM;
711
712 /* Create TCE table */
713 ret = tce_iommu_create_table(container, table_group, num,
714 page_shift, window_size, levels, &tbl);
715 if (ret)
716 return ret;
717
718 BUG_ON(!tbl->it_ops->free);
719
720 /*
721 * Program the table to every group.
722 * Groups have been tested for compatibility at the attach time.
723 */
724 list_for_each_entry(tcegrp, &container->group_list, next) {
725 table_group = iommu_group_get_iommudata(tcegrp->grp);
726
727 ret = table_group->ops->set_window(table_group, num, tbl);
728 if (ret)
729 goto unset_exit;
730 }
731
732 container->tables[num] = tbl;
733
734 /* Return start address assigned by platform in create_table() */
735 *start_addr = tbl->it_offset << tbl->it_page_shift;
736
737 return 0;
738
739 unset_exit:
740 list_for_each_entry(tcegrp, &container->group_list, next) {
741 table_group = iommu_group_get_iommudata(tcegrp->grp);
742 table_group->ops->unset_window(table_group, num);
743 }
744 tce_iommu_free_table(container, tbl);
745
746 return ret;
747 }
748
749 static long tce_iommu_remove_window(struct tce_container *container,
750 __u64 start_addr)
751 {
752 struct iommu_table_group *table_group = NULL;
753 struct iommu_table *tbl;
754 struct tce_iommu_group *tcegrp;
755 int num;
756
757 num = tce_iommu_find_table(container, start_addr, &tbl);
758 if (num < 0)
759 return -EINVAL;
760
761 BUG_ON(!tbl->it_size);
762
763 /* Detach groups from IOMMUs */
764 list_for_each_entry(tcegrp, &container->group_list, next) {
765 table_group = iommu_group_get_iommudata(tcegrp->grp);
766
767 /*
768 * SPAPR TCE IOMMU exposes the default DMA window to
769 * the guest via dma32_window_start/size of
770 * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
771 * the userspace to remove this window, some do not so
772 * here we check for the platform capability.
773 */
774 if (!table_group->ops || !table_group->ops->unset_window)
775 return -EPERM;
776
777 table_group->ops->unset_window(table_group, num);
778 }
779
780 /* Free table */
781 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
782 tce_iommu_free_table(container, tbl);
783 container->tables[num] = NULL;
784
785 return 0;
786 }
787
788 static long tce_iommu_create_default_window(struct tce_container *container)
789 {
790 long ret;
791 __u64 start_addr = 0;
792 struct tce_iommu_group *tcegrp;
793 struct iommu_table_group *table_group;
794
795 if (!container->def_window_pending)
796 return 0;
797
798 if (!tce_groups_attached(container))
799 return -ENODEV;
800
801 tcegrp = list_first_entry(&container->group_list,
802 struct tce_iommu_group, next);
803 table_group = iommu_group_get_iommudata(tcegrp->grp);
804 if (!table_group)
805 return -ENODEV;
806
807 ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
808 table_group->tce32_size, 1, &start_addr);
809 WARN_ON_ONCE(!ret && start_addr);
810
811 if (!ret)
812 container->def_window_pending = false;
813
814 return ret;
815 }
816
817 static long tce_iommu_ioctl(void *iommu_data,
818 unsigned int cmd, unsigned long arg)
819 {
820 struct tce_container *container = iommu_data;
821 unsigned long minsz, ddwsz;
822 long ret;
823
824 switch (cmd) {
825 case VFIO_CHECK_EXTENSION:
826 switch (arg) {
827 case VFIO_SPAPR_TCE_IOMMU:
828 case VFIO_SPAPR_TCE_v2_IOMMU:
829 ret = 1;
830 break;
831 default:
832 ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
833 break;
834 }
835
836 return (ret < 0) ? 0 : ret;
837 }
838
839 /*
840 * Sanity check to prevent one userspace from manipulating
841 * another userspace mm.
842 */
843 BUG_ON(!container);
844 if (container->mm && container->mm != current->mm)
845 return -EPERM;
846
847 switch (cmd) {
848 case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
849 struct vfio_iommu_spapr_tce_info info;
850 struct tce_iommu_group *tcegrp;
851 struct iommu_table_group *table_group;
852
853 if (!tce_groups_attached(container))
854 return -ENXIO;
855
856 tcegrp = list_first_entry(&container->group_list,
857 struct tce_iommu_group, next);
858 table_group = iommu_group_get_iommudata(tcegrp->grp);
859
860 if (!table_group)
861 return -ENXIO;
862
863 minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
864 dma32_window_size);
865
866 if (copy_from_user(&info, (void __user *)arg, minsz))
867 return -EFAULT;
868
869 if (info.argsz < minsz)
870 return -EINVAL;
871
872 info.dma32_window_start = table_group->tce32_start;
873 info.dma32_window_size = table_group->tce32_size;
874 info.flags = 0;
875 memset(&info.ddw, 0, sizeof(info.ddw));
876
877 if (table_group->max_dynamic_windows_supported &&
878 container->v2) {
879 info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
880 info.ddw.pgsizes = table_group->pgsizes;
881 info.ddw.max_dynamic_windows_supported =
882 table_group->max_dynamic_windows_supported;
883 info.ddw.levels = table_group->max_levels;
884 }
885
886 ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
887
888 if (info.argsz >= ddwsz)
889 minsz = ddwsz;
890
891 if (copy_to_user((void __user *)arg, &info, minsz))
892 return -EFAULT;
893
894 return 0;
895 }
896 case VFIO_IOMMU_MAP_DMA: {
897 struct vfio_iommu_type1_dma_map param;
898 struct iommu_table *tbl = NULL;
899 long num;
900 enum dma_data_direction direction;
901
902 if (!container->enabled)
903 return -EPERM;
904
905 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
906
907 if (copy_from_user(&param, (void __user *)arg, minsz))
908 return -EFAULT;
909
910 if (param.argsz < minsz)
911 return -EINVAL;
912
913 if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
914 VFIO_DMA_MAP_FLAG_WRITE))
915 return -EINVAL;
916
917 ret = tce_iommu_create_default_window(container);
918 if (ret)
919 return ret;
920
921 num = tce_iommu_find_table(container, param.iova, &tbl);
922 if (num < 0)
923 return -ENXIO;
924
925 if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
926 (param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
927 return -EINVAL;
928
929 /* iova is checked by the IOMMU API */
930 if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
931 if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
932 direction = DMA_BIDIRECTIONAL;
933 else
934 direction = DMA_TO_DEVICE;
935 } else {
936 if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
937 direction = DMA_FROM_DEVICE;
938 else
939 return -EINVAL;
940 }
941
942 ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
943 if (ret)
944 return ret;
945
946 if (container->v2)
947 ret = tce_iommu_build_v2(container, tbl,
948 param.iova >> tbl->it_page_shift,
949 param.vaddr,
950 param.size >> tbl->it_page_shift,
951 direction);
952 else
953 ret = tce_iommu_build(container, tbl,
954 param.iova >> tbl->it_page_shift,
955 param.vaddr,
956 param.size >> tbl->it_page_shift,
957 direction);
958
959 iommu_flush_tce(tbl);
960
961 return ret;
962 }
963 case VFIO_IOMMU_UNMAP_DMA: {
964 struct vfio_iommu_type1_dma_unmap param;
965 struct iommu_table *tbl = NULL;
966 long num;
967
968 if (!container->enabled)
969 return -EPERM;
970
971 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
972 size);
973
974 if (copy_from_user(&param, (void __user *)arg, minsz))
975 return -EFAULT;
976
977 if (param.argsz < minsz)
978 return -EINVAL;
979
980 /* No flag is supported now */
981 if (param.flags)
982 return -EINVAL;
983
984 ret = tce_iommu_create_default_window(container);
985 if (ret)
986 return ret;
987
988 num = tce_iommu_find_table(container, param.iova, &tbl);
989 if (num < 0)
990 return -ENXIO;
991
992 if (param.size & ~IOMMU_PAGE_MASK(tbl))
993 return -EINVAL;
994
995 ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
996 param.size >> tbl->it_page_shift);
997 if (ret)
998 return ret;
999
1000 ret = tce_iommu_clear(container, tbl,
1001 param.iova >> tbl->it_page_shift,
1002 param.size >> tbl->it_page_shift);
1003 iommu_flush_tce(tbl);
1004
1005 return ret;
1006 }
1007 case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
1008 struct vfio_iommu_spapr_register_memory param;
1009
1010 if (!container->v2)
1011 break;
1012
1013 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1014 size);
1015
1016 ret = tce_iommu_mm_set(container);
1017 if (ret)
1018 return ret;
1019
1020 if (copy_from_user(&param, (void __user *)arg, minsz))
1021 return -EFAULT;
1022
1023 if (param.argsz < minsz)
1024 return -EINVAL;
1025
1026 /* No flag is supported now */
1027 if (param.flags)
1028 return -EINVAL;
1029
1030 mutex_lock(&container->lock);
1031 ret = tce_iommu_register_pages(container, param.vaddr,
1032 param.size);
1033 mutex_unlock(&container->lock);
1034
1035 return ret;
1036 }
1037 case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
1038 struct vfio_iommu_spapr_register_memory param;
1039
1040 if (!container->v2)
1041 break;
1042
1043 if (!container->mm)
1044 return -EPERM;
1045
1046 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1047 size);
1048
1049 if (copy_from_user(&param, (void __user *)arg, minsz))
1050 return -EFAULT;
1051
1052 if (param.argsz < minsz)
1053 return -EINVAL;
1054
1055 /* No flag is supported now */
1056 if (param.flags)
1057 return -EINVAL;
1058
1059 mutex_lock(&container->lock);
1060 ret = tce_iommu_unregister_pages(container, param.vaddr,
1061 param.size);
1062 mutex_unlock(&container->lock);
1063
1064 return ret;
1065 }
1066 case VFIO_IOMMU_ENABLE:
1067 if (container->v2)
1068 break;
1069
1070 mutex_lock(&container->lock);
1071 ret = tce_iommu_enable(container);
1072 mutex_unlock(&container->lock);
1073 return ret;
1074
1075
1076 case VFIO_IOMMU_DISABLE:
1077 if (container->v2)
1078 break;
1079
1080 mutex_lock(&container->lock);
1081 tce_iommu_disable(container);
1082 mutex_unlock(&container->lock);
1083 return 0;
1084
1085 case VFIO_EEH_PE_OP: {
1086 struct tce_iommu_group *tcegrp;
1087
1088 ret = 0;
1089 list_for_each_entry(tcegrp, &container->group_list, next) {
1090 ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
1091 cmd, arg);
1092 if (ret)
1093 return ret;
1094 }
1095 return ret;
1096 }
1097
1098 case VFIO_IOMMU_SPAPR_TCE_CREATE: {
1099 struct vfio_iommu_spapr_tce_create create;
1100
1101 if (!container->v2)
1102 break;
1103
1104 ret = tce_iommu_mm_set(container);
1105 if (ret)
1106 return ret;
1107
1108 if (!tce_groups_attached(container))
1109 return -ENXIO;
1110
1111 minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
1112 start_addr);
1113
1114 if (copy_from_user(&create, (void __user *)arg, minsz))
1115 return -EFAULT;
1116
1117 if (create.argsz < minsz)
1118 return -EINVAL;
1119
1120 if (create.flags)
1121 return -EINVAL;
1122
1123 mutex_lock(&container->lock);
1124
1125 ret = tce_iommu_create_default_window(container);
1126 if (!ret)
1127 ret = tce_iommu_create_window(container,
1128 create.page_shift,
1129 create.window_size, create.levels,
1130 &create.start_addr);
1131
1132 mutex_unlock(&container->lock);
1133
1134 if (!ret && copy_to_user((void __user *)arg, &create, minsz))
1135 ret = -EFAULT;
1136
1137 return ret;
1138 }
1139 case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
1140 struct vfio_iommu_spapr_tce_remove remove;
1141
1142 if (!container->v2)
1143 break;
1144
1145 ret = tce_iommu_mm_set(container);
1146 if (ret)
1147 return ret;
1148
1149 if (!tce_groups_attached(container))
1150 return -ENXIO;
1151
1152 minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
1153 start_addr);
1154
1155 if (copy_from_user(&remove, (void __user *)arg, minsz))
1156 return -EFAULT;
1157
1158 if (remove.argsz < minsz)
1159 return -EINVAL;
1160
1161 if (remove.flags)
1162 return -EINVAL;
1163
1164 if (container->def_window_pending && !remove.start_addr) {
1165 container->def_window_pending = false;
1166 return 0;
1167 }
1168
1169 mutex_lock(&container->lock);
1170
1171 ret = tce_iommu_remove_window(container, remove.start_addr);
1172
1173 mutex_unlock(&container->lock);
1174
1175 return ret;
1176 }
1177 }
1178
1179 return -ENOTTY;
1180 }
1181
1182 static void tce_iommu_release_ownership(struct tce_container *container,
1183 struct iommu_table_group *table_group)
1184 {
1185 int i;
1186
1187 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1188 struct iommu_table *tbl = container->tables[i];
1189
1190 if (!tbl)
1191 continue;
1192
1193 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
1194 if (tbl->it_map)
1195 iommu_release_ownership(tbl);
1196
1197 container->tables[i] = NULL;
1198 }
1199 }
1200
1201 static int tce_iommu_take_ownership(struct tce_container *container,
1202 struct iommu_table_group *table_group)
1203 {
1204 int i, j, rc = 0;
1205
1206 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1207 struct iommu_table *tbl = table_group->tables[i];
1208
1209 if (!tbl || !tbl->it_map)
1210 continue;
1211
1212 rc = iommu_take_ownership(tbl);
1213 if (rc) {
1214 for (j = 0; j < i; ++j)
1215 iommu_release_ownership(
1216 table_group->tables[j]);
1217
1218 return rc;
1219 }
1220 }
1221
1222 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1223 container->tables[i] = table_group->tables[i];
1224
1225 return 0;
1226 }
1227
1228 static void tce_iommu_release_ownership_ddw(struct tce_container *container,
1229 struct iommu_table_group *table_group)
1230 {
1231 long i;
1232
1233 if (!table_group->ops->unset_window) {
1234 WARN_ON_ONCE(1);
1235 return;
1236 }
1237
1238 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1239 if (container->tables[i])
1240 table_group->ops->unset_window(table_group, i);
1241
1242 table_group->ops->release_ownership(table_group);
1243 }
1244
1245 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
1246 struct iommu_table_group *table_group)
1247 {
1248 long i, ret = 0;
1249
1250 if (!table_group->ops->create_table || !table_group->ops->set_window ||
1251 !table_group->ops->release_ownership) {
1252 WARN_ON_ONCE(1);
1253 return -EFAULT;
1254 }
1255
1256 table_group->ops->take_ownership(table_group);
1257
1258 /* Set all windows to the new group */
1259 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1260 struct iommu_table *tbl = container->tables[i];
1261
1262 if (!tbl)
1263 continue;
1264
1265 ret = table_group->ops->set_window(table_group, i, tbl);
1266 if (ret)
1267 goto release_exit;
1268 }
1269
1270 return 0;
1271
1272 release_exit:
1273 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1274 table_group->ops->unset_window(table_group, i);
1275
1276 table_group->ops->release_ownership(table_group);
1277
1278 return ret;
1279 }
1280
1281 static int tce_iommu_attach_group(void *iommu_data,
1282 struct iommu_group *iommu_group)
1283 {
1284 int ret;
1285 struct tce_container *container = iommu_data;
1286 struct iommu_table_group *table_group;
1287 struct tce_iommu_group *tcegrp = NULL;
1288
1289 mutex_lock(&container->lock);
1290
1291 /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
1292 iommu_group_id(iommu_group), iommu_group); */
1293 table_group = iommu_group_get_iommudata(iommu_group);
1294 if (!table_group) {
1295 ret = -ENODEV;
1296 goto unlock_exit;
1297 }
1298
1299 if (tce_groups_attached(container) && (!table_group->ops ||
1300 !table_group->ops->take_ownership ||
1301 !table_group->ops->release_ownership)) {
1302 ret = -EBUSY;
1303 goto unlock_exit;
1304 }
1305
1306 /* Check if new group has the same iommu_ops (i.e. compatible) */
1307 list_for_each_entry(tcegrp, &container->group_list, next) {
1308 struct iommu_table_group *table_group_tmp;
1309
1310 if (tcegrp->grp == iommu_group) {
1311 pr_warn("tce_vfio: Group %d is already attached\n",
1312 iommu_group_id(iommu_group));
1313 ret = -EBUSY;
1314 goto unlock_exit;
1315 }
1316 table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
1317 if (table_group_tmp->ops->create_table !=
1318 table_group->ops->create_table) {
1319 pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
1320 iommu_group_id(iommu_group),
1321 iommu_group_id(tcegrp->grp));
1322 ret = -EPERM;
1323 goto unlock_exit;
1324 }
1325 }
1326
1327 tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
1328 if (!tcegrp) {
1329 ret = -ENOMEM;
1330 goto unlock_exit;
1331 }
1332
1333 if (!table_group->ops || !table_group->ops->take_ownership ||
1334 !table_group->ops->release_ownership) {
1335 if (container->v2) {
1336 ret = -EPERM;
1337 goto unlock_exit;
1338 }
1339 ret = tce_iommu_take_ownership(container, table_group);
1340 } else {
1341 if (!container->v2) {
1342 ret = -EPERM;
1343 goto unlock_exit;
1344 }
1345 ret = tce_iommu_take_ownership_ddw(container, table_group);
1346 if (!tce_groups_attached(container) && !container->tables[0])
1347 container->def_window_pending = true;
1348 }
1349
1350 if (!ret) {
1351 tcegrp->grp = iommu_group;
1352 list_add(&tcegrp->next, &container->group_list);
1353 }
1354
1355 unlock_exit:
1356 if (ret && tcegrp)
1357 kfree(tcegrp);
1358
1359 mutex_unlock(&container->lock);
1360
1361 return ret;
1362 }
1363
1364 static void tce_iommu_detach_group(void *iommu_data,
1365 struct iommu_group *iommu_group)
1366 {
1367 struct tce_container *container = iommu_data;
1368 struct iommu_table_group *table_group;
1369 bool found = false;
1370 struct tce_iommu_group *tcegrp;
1371
1372 mutex_lock(&container->lock);
1373
1374 list_for_each_entry(tcegrp, &container->group_list, next) {
1375 if (tcegrp->grp == iommu_group) {
1376 found = true;
1377 break;
1378 }
1379 }
1380
1381 if (!found) {
1382 pr_warn("tce_vfio: detaching unattached group #%u\n",
1383 iommu_group_id(iommu_group));
1384 goto unlock_exit;
1385 }
1386
1387 list_del(&tcegrp->next);
1388 kfree(tcegrp);
1389
1390 table_group = iommu_group_get_iommudata(iommu_group);
1391 BUG_ON(!table_group);
1392
1393 if (!table_group->ops || !table_group->ops->release_ownership)
1394 tce_iommu_release_ownership(container, table_group);
1395 else
1396 tce_iommu_release_ownership_ddw(container, table_group);
1397
1398 unlock_exit:
1399 mutex_unlock(&container->lock);
1400 }
1401
1402 static const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
1403 .name = "iommu-vfio-powerpc",
1404 .owner = THIS_MODULE,
1405 .open = tce_iommu_open,
1406 .release = tce_iommu_release,
1407 .ioctl = tce_iommu_ioctl,
1408 .attach_group = tce_iommu_attach_group,
1409 .detach_group = tce_iommu_detach_group,
1410 };
1411
1412 static int __init tce_iommu_init(void)
1413 {
1414 return vfio_register_iommu_driver(&tce_iommu_driver_ops);
1415 }
1416
1417 static void __exit tce_iommu_cleanup(void)
1418 {
1419 vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
1420 }
1421
1422 module_init(tce_iommu_init);
1423 module_exit(tce_iommu_cleanup);
1424
1425 MODULE_VERSION(DRIVER_VERSION);
1426 MODULE_LICENSE("GPL v2");
1427 MODULE_AUTHOR(DRIVER_AUTHOR);
1428 MODULE_DESCRIPTION(DRIVER_DESC);
1429
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