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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * IOMMU API for s390 PCI devices
4 *
5 * Copyright IBM Corp. 2015
6 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
7 */
8
9#include <linux/pci.h>
10#include <linux/iommu.h>
11#include <linux/iommu-helper.h>
12#include <linux/sizes.h>
13#include <linux/rculist.h>
14#include <linux/rcupdate.h>
15#include <asm/pci_dma.h>
16
17#include "dma-iommu.h"
18
19static const struct iommu_ops s390_iommu_ops;
20
21static struct kmem_cache *dma_region_table_cache;
22static struct kmem_cache *dma_page_table_cache;
23
24static u64 s390_iommu_aperture;
25static u32 s390_iommu_aperture_factor = 1;
26
27struct s390_domain {
28 struct iommu_domain domain;
29 struct list_head devices;
30 struct zpci_iommu_ctrs ctrs;
31 unsigned long *dma_table;
32 spinlock_t list_lock;
33 struct rcu_head rcu;
34};
35
36static inline unsigned int calc_rtx(dma_addr_t ptr)
37{
38 return ((unsigned long)ptr >> ZPCI_RT_SHIFT) & ZPCI_INDEX_MASK;
39}
40
41static inline unsigned int calc_sx(dma_addr_t ptr)
42{
43 return ((unsigned long)ptr >> ZPCI_ST_SHIFT) & ZPCI_INDEX_MASK;
44}
45
46static inline unsigned int calc_px(dma_addr_t ptr)
47{
48 return ((unsigned long)ptr >> PAGE_SHIFT) & ZPCI_PT_MASK;
49}
50
51static inline void set_pt_pfaa(unsigned long *entry, phys_addr_t pfaa)
52{
53 *entry &= ZPCI_PTE_FLAG_MASK;
54 *entry |= (pfaa & ZPCI_PTE_ADDR_MASK);
55}
56
57static inline void set_rt_sto(unsigned long *entry, phys_addr_t sto)
58{
59 *entry &= ZPCI_RTE_FLAG_MASK;
60 *entry |= (sto & ZPCI_RTE_ADDR_MASK);
61 *entry |= ZPCI_TABLE_TYPE_RTX;
62}
63
64static inline void set_st_pto(unsigned long *entry, phys_addr_t pto)
65{
66 *entry &= ZPCI_STE_FLAG_MASK;
67 *entry |= (pto & ZPCI_STE_ADDR_MASK);
68 *entry |= ZPCI_TABLE_TYPE_SX;
69}
70
71static inline void validate_rt_entry(unsigned long *entry)
72{
73 *entry &= ~ZPCI_TABLE_VALID_MASK;
74 *entry &= ~ZPCI_TABLE_OFFSET_MASK;
75 *entry |= ZPCI_TABLE_VALID;
76 *entry |= ZPCI_TABLE_LEN_RTX;
77}
78
79static inline void validate_st_entry(unsigned long *entry)
80{
81 *entry &= ~ZPCI_TABLE_VALID_MASK;
82 *entry |= ZPCI_TABLE_VALID;
83}
84
85static inline void invalidate_pt_entry(unsigned long *entry)
86{
87 WARN_ON_ONCE((*entry & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_INVALID);
88 *entry &= ~ZPCI_PTE_VALID_MASK;
89 *entry |= ZPCI_PTE_INVALID;
90}
91
92static inline void validate_pt_entry(unsigned long *entry)
93{
94 WARN_ON_ONCE((*entry & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID);
95 *entry &= ~ZPCI_PTE_VALID_MASK;
96 *entry |= ZPCI_PTE_VALID;
97}
98
99static inline void entry_set_protected(unsigned long *entry)
100{
101 *entry &= ~ZPCI_TABLE_PROT_MASK;
102 *entry |= ZPCI_TABLE_PROTECTED;
103}
104
105static inline void entry_clr_protected(unsigned long *entry)
106{
107 *entry &= ~ZPCI_TABLE_PROT_MASK;
108 *entry |= ZPCI_TABLE_UNPROTECTED;
109}
110
111static inline int reg_entry_isvalid(unsigned long entry)
112{
113 return (entry & ZPCI_TABLE_VALID_MASK) == ZPCI_TABLE_VALID;
114}
115
116static inline int pt_entry_isvalid(unsigned long entry)
117{
118 return (entry & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID;
119}
120
121static inline unsigned long *get_rt_sto(unsigned long entry)
122{
123 if ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_RTX)
124 return phys_to_virt(entry & ZPCI_RTE_ADDR_MASK);
125 else
126 return NULL;
127}
128
129static inline unsigned long *get_st_pto(unsigned long entry)
130{
131 if ((entry & ZPCI_TABLE_TYPE_MASK) == ZPCI_TABLE_TYPE_SX)
132 return phys_to_virt(entry & ZPCI_STE_ADDR_MASK);
133 else
134 return NULL;
135}
136
137static int __init dma_alloc_cpu_table_caches(void)
138{
139 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
140 ZPCI_TABLE_SIZE,
141 ZPCI_TABLE_ALIGN,
142 0, NULL);
143 if (!dma_region_table_cache)
144 return -ENOMEM;
145
146 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
147 ZPCI_PT_SIZE,
148 ZPCI_PT_ALIGN,
149 0, NULL);
150 if (!dma_page_table_cache) {
151 kmem_cache_destroy(dma_region_table_cache);
152 return -ENOMEM;
153 }
154 return 0;
155}
156
157static unsigned long *dma_alloc_cpu_table(gfp_t gfp)
158{
159 unsigned long *table, *entry;
160
161 table = kmem_cache_alloc(dma_region_table_cache, gfp);
162 if (!table)
163 return NULL;
164
165 for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
166 *entry = ZPCI_TABLE_INVALID;
167 return table;
168}
169
170static void dma_free_cpu_table(void *table)
171{
172 kmem_cache_free(dma_region_table_cache, table);
173}
174
175static void dma_free_page_table(void *table)
176{
177 kmem_cache_free(dma_page_table_cache, table);
178}
179
180static void dma_free_seg_table(unsigned long entry)
181{
182 unsigned long *sto = get_rt_sto(entry);
183 int sx;
184
185 for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
186 if (reg_entry_isvalid(sto[sx]))
187 dma_free_page_table(get_st_pto(sto[sx]));
188
189 dma_free_cpu_table(sto);
190}
191
192static void dma_cleanup_tables(unsigned long *table)
193{
194 int rtx;
195
196 if (!table)
197 return;
198
199 for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
200 if (reg_entry_isvalid(table[rtx]))
201 dma_free_seg_table(table[rtx]);
202
203 dma_free_cpu_table(table);
204}
205
206static unsigned long *dma_alloc_page_table(gfp_t gfp)
207{
208 unsigned long *table, *entry;
209
210 table = kmem_cache_alloc(dma_page_table_cache, gfp);
211 if (!table)
212 return NULL;
213
214 for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
215 *entry = ZPCI_PTE_INVALID;
216 return table;
217}
218
219static unsigned long *dma_get_seg_table_origin(unsigned long *rtep, gfp_t gfp)
220{
221 unsigned long old_rte, rte;
222 unsigned long *sto;
223
224 rte = READ_ONCE(*rtep);
225 if (reg_entry_isvalid(rte)) {
226 sto = get_rt_sto(rte);
227 } else {
228 sto = dma_alloc_cpu_table(gfp);
229 if (!sto)
230 return NULL;
231
232 set_rt_sto(&rte, virt_to_phys(sto));
233 validate_rt_entry(&rte);
234 entry_clr_protected(&rte);
235
236 old_rte = cmpxchg(rtep, ZPCI_TABLE_INVALID, rte);
237 if (old_rte != ZPCI_TABLE_INVALID) {
238 /* Somone else was faster, use theirs */
239 dma_free_cpu_table(sto);
240 sto = get_rt_sto(old_rte);
241 }
242 }
243 return sto;
244}
245
246static unsigned long *dma_get_page_table_origin(unsigned long *step, gfp_t gfp)
247{
248 unsigned long old_ste, ste;
249 unsigned long *pto;
250
251 ste = READ_ONCE(*step);
252 if (reg_entry_isvalid(ste)) {
253 pto = get_st_pto(ste);
254 } else {
255 pto = dma_alloc_page_table(gfp);
256 if (!pto)
257 return NULL;
258 set_st_pto(&ste, virt_to_phys(pto));
259 validate_st_entry(&ste);
260 entry_clr_protected(&ste);
261
262 old_ste = cmpxchg(step, ZPCI_TABLE_INVALID, ste);
263 if (old_ste != ZPCI_TABLE_INVALID) {
264 /* Somone else was faster, use theirs */
265 dma_free_page_table(pto);
266 pto = get_st_pto(old_ste);
267 }
268 }
269 return pto;
270}
271
272static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr, gfp_t gfp)
273{
274 unsigned long *sto, *pto;
275 unsigned int rtx, sx, px;
276
277 rtx = calc_rtx(dma_addr);
278 sto = dma_get_seg_table_origin(&rto[rtx], gfp);
279 if (!sto)
280 return NULL;
281
282 sx = calc_sx(dma_addr);
283 pto = dma_get_page_table_origin(&sto[sx], gfp);
284 if (!pto)
285 return NULL;
286
287 px = calc_px(dma_addr);
288 return &pto[px];
289}
290
291static void dma_update_cpu_trans(unsigned long *ptep, phys_addr_t page_addr, int flags)
292{
293 unsigned long pte;
294
295 pte = READ_ONCE(*ptep);
296 if (flags & ZPCI_PTE_INVALID) {
297 invalidate_pt_entry(&pte);
298 } else {
299 set_pt_pfaa(&pte, page_addr);
300 validate_pt_entry(&pte);
301 }
302
303 if (flags & ZPCI_TABLE_PROTECTED)
304 entry_set_protected(&pte);
305 else
306 entry_clr_protected(&pte);
307
308 xchg(ptep, pte);
309}
310
311static struct s390_domain *to_s390_domain(struct iommu_domain *dom)
312{
313 return container_of(dom, struct s390_domain, domain);
314}
315
316static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap)
317{
318 struct zpci_dev *zdev = to_zpci_dev(dev);
319
320 switch (cap) {
321 case IOMMU_CAP_CACHE_COHERENCY:
322 return true;
323 case IOMMU_CAP_DEFERRED_FLUSH:
324 return zdev->pft != PCI_FUNC_TYPE_ISM;
325 default:
326 return false;
327 }
328}
329
330static struct iommu_domain *s390_domain_alloc_paging(struct device *dev)
331{
332 struct s390_domain *s390_domain;
333
334 s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL);
335 if (!s390_domain)
336 return NULL;
337
338 s390_domain->dma_table = dma_alloc_cpu_table(GFP_KERNEL);
339 if (!s390_domain->dma_table) {
340 kfree(s390_domain);
341 return NULL;
342 }
343 s390_domain->domain.geometry.force_aperture = true;
344 s390_domain->domain.geometry.aperture_start = 0;
345 s390_domain->domain.geometry.aperture_end = ZPCI_TABLE_SIZE_RT - 1;
346
347 spin_lock_init(&s390_domain->list_lock);
348 INIT_LIST_HEAD_RCU(&s390_domain->devices);
349
350 return &s390_domain->domain;
351}
352
353static void s390_iommu_rcu_free_domain(struct rcu_head *head)
354{
355 struct s390_domain *s390_domain = container_of(head, struct s390_domain, rcu);
356
357 dma_cleanup_tables(s390_domain->dma_table);
358 kfree(s390_domain);
359}
360
361static void s390_domain_free(struct iommu_domain *domain)
362{
363 struct s390_domain *s390_domain = to_s390_domain(domain);
364
365 rcu_read_lock();
366 WARN_ON(!list_empty(&s390_domain->devices));
367 rcu_read_unlock();
368
369 call_rcu(&s390_domain->rcu, s390_iommu_rcu_free_domain);
370}
371
372static void s390_iommu_detach_device(struct iommu_domain *domain,
373 struct device *dev)
374{
375 struct s390_domain *s390_domain = to_s390_domain(domain);
376 struct zpci_dev *zdev = to_zpci_dev(dev);
377 unsigned long flags;
378
379 spin_lock_irqsave(&s390_domain->list_lock, flags);
380 list_del_rcu(&zdev->iommu_list);
381 spin_unlock_irqrestore(&s390_domain->list_lock, flags);
382
383 zpci_unregister_ioat(zdev, 0);
384 zdev->s390_domain = NULL;
385 zdev->dma_table = NULL;
386}
387
388static int s390_iommu_attach_device(struct iommu_domain *domain,
389 struct device *dev)
390{
391 struct s390_domain *s390_domain = to_s390_domain(domain);
392 struct zpci_dev *zdev = to_zpci_dev(dev);
393 unsigned long flags;
394 u8 status;
395 int cc;
396
397 if (!zdev)
398 return -ENODEV;
399
400 if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma ||
401 domain->geometry.aperture_end < zdev->start_dma))
402 return -EINVAL;
403
404 if (zdev->s390_domain)
405 s390_iommu_detach_device(&zdev->s390_domain->domain, dev);
406
407 cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
408 virt_to_phys(s390_domain->dma_table), &status);
409 /*
410 * If the device is undergoing error recovery the reset code
411 * will re-establish the new domain.
412 */
413 if (cc && status != ZPCI_PCI_ST_FUNC_NOT_AVAIL)
414 return -EIO;
415
416 zdev->dma_table = s390_domain->dma_table;
417 zdev->s390_domain = s390_domain;
418
419 spin_lock_irqsave(&s390_domain->list_lock, flags);
420 list_add_rcu(&zdev->iommu_list, &s390_domain->devices);
421 spin_unlock_irqrestore(&s390_domain->list_lock, flags);
422
423 return 0;
424}
425
426static void s390_iommu_get_resv_regions(struct device *dev,
427 struct list_head *list)
428{
429 struct zpci_dev *zdev = to_zpci_dev(dev);
430 struct iommu_resv_region *region;
431
432 if (zdev->start_dma) {
433 region = iommu_alloc_resv_region(0, zdev->start_dma, 0,
434 IOMMU_RESV_RESERVED, GFP_KERNEL);
435 if (!region)
436 return;
437 list_add_tail(®ion->list, list);
438 }
439
440 if (zdev->end_dma < ZPCI_TABLE_SIZE_RT - 1) {
441 region = iommu_alloc_resv_region(zdev->end_dma + 1,
442 ZPCI_TABLE_SIZE_RT - zdev->end_dma - 1,
443 0, IOMMU_RESV_RESERVED, GFP_KERNEL);
444 if (!region)
445 return;
446 list_add_tail(®ion->list, list);
447 }
448}
449
450static struct iommu_device *s390_iommu_probe_device(struct device *dev)
451{
452 struct zpci_dev *zdev;
453
454 if (!dev_is_pci(dev))
455 return ERR_PTR(-ENODEV);
456
457 zdev = to_zpci_dev(dev);
458
459 if (zdev->start_dma > zdev->end_dma ||
460 zdev->start_dma > ZPCI_TABLE_SIZE_RT - 1)
461 return ERR_PTR(-EINVAL);
462
463 if (zdev->end_dma > ZPCI_TABLE_SIZE_RT - 1)
464 zdev->end_dma = ZPCI_TABLE_SIZE_RT - 1;
465
466 if (zdev->tlb_refresh)
467 dev->iommu->shadow_on_flush = 1;
468
469 return &zdev->iommu_dev;
470}
471
472static void s390_iommu_release_device(struct device *dev)
473{
474 struct zpci_dev *zdev = to_zpci_dev(dev);
475
476 /*
477 * release_device is expected to detach any domain currently attached
478 * to the device, but keep it attached to other devices in the group.
479 */
480 if (zdev)
481 s390_iommu_detach_device(&zdev->s390_domain->domain, dev);
482}
483
484static int zpci_refresh_all(struct zpci_dev *zdev)
485{
486 return zpci_refresh_trans((u64)zdev->fh << 32, zdev->start_dma,
487 zdev->end_dma - zdev->start_dma + 1);
488}
489
490static void s390_iommu_flush_iotlb_all(struct iommu_domain *domain)
491{
492 struct s390_domain *s390_domain = to_s390_domain(domain);
493 struct zpci_dev *zdev;
494
495 rcu_read_lock();
496 list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) {
497 atomic64_inc(&s390_domain->ctrs.global_rpcits);
498 zpci_refresh_all(zdev);
499 }
500 rcu_read_unlock();
501}
502
503static void s390_iommu_iotlb_sync(struct iommu_domain *domain,
504 struct iommu_iotlb_gather *gather)
505{
506 struct s390_domain *s390_domain = to_s390_domain(domain);
507 size_t size = gather->end - gather->start + 1;
508 struct zpci_dev *zdev;
509
510 /* If gather was never added to there is nothing to flush */
511 if (!gather->end)
512 return;
513
514 rcu_read_lock();
515 list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) {
516 atomic64_inc(&s390_domain->ctrs.sync_rpcits);
517 zpci_refresh_trans((u64)zdev->fh << 32, gather->start,
518 size);
519 }
520 rcu_read_unlock();
521}
522
523static int s390_iommu_iotlb_sync_map(struct iommu_domain *domain,
524 unsigned long iova, size_t size)
525{
526 struct s390_domain *s390_domain = to_s390_domain(domain);
527 struct zpci_dev *zdev;
528 int ret = 0;
529
530 rcu_read_lock();
531 list_for_each_entry_rcu(zdev, &s390_domain->devices, iommu_list) {
532 if (!zdev->tlb_refresh)
533 continue;
534 atomic64_inc(&s390_domain->ctrs.sync_map_rpcits);
535 ret = zpci_refresh_trans((u64)zdev->fh << 32,
536 iova, size);
537 /*
538 * let the hypervisor discover invalidated entries
539 * allowing it to free IOVAs and unpin pages
540 */
541 if (ret == -ENOMEM) {
542 ret = zpci_refresh_all(zdev);
543 if (ret)
544 break;
545 }
546 }
547 rcu_read_unlock();
548
549 return ret;
550}
551
552static int s390_iommu_validate_trans(struct s390_domain *s390_domain,
553 phys_addr_t pa, dma_addr_t dma_addr,
554 unsigned long nr_pages, int flags,
555 gfp_t gfp)
556{
557 phys_addr_t page_addr = pa & PAGE_MASK;
558 unsigned long *entry;
559 unsigned long i;
560 int rc;
561
562 for (i = 0; i < nr_pages; i++) {
563 entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr,
564 gfp);
565 if (unlikely(!entry)) {
566 rc = -ENOMEM;
567 goto undo_cpu_trans;
568 }
569 dma_update_cpu_trans(entry, page_addr, flags);
570 page_addr += PAGE_SIZE;
571 dma_addr += PAGE_SIZE;
572 }
573
574 return 0;
575
576undo_cpu_trans:
577 while (i-- > 0) {
578 dma_addr -= PAGE_SIZE;
579 entry = dma_walk_cpu_trans(s390_domain->dma_table,
580 dma_addr, gfp);
581 if (!entry)
582 break;
583 dma_update_cpu_trans(entry, 0, ZPCI_PTE_INVALID);
584 }
585
586 return rc;
587}
588
589static int s390_iommu_invalidate_trans(struct s390_domain *s390_domain,
590 dma_addr_t dma_addr, unsigned long nr_pages)
591{
592 unsigned long *entry;
593 unsigned long i;
594 int rc = 0;
595
596 for (i = 0; i < nr_pages; i++) {
597 entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr,
598 GFP_ATOMIC);
599 if (unlikely(!entry)) {
600 rc = -EINVAL;
601 break;
602 }
603 dma_update_cpu_trans(entry, 0, ZPCI_PTE_INVALID);
604 dma_addr += PAGE_SIZE;
605 }
606
607 return rc;
608}
609
610static int s390_iommu_map_pages(struct iommu_domain *domain,
611 unsigned long iova, phys_addr_t paddr,
612 size_t pgsize, size_t pgcount,
613 int prot, gfp_t gfp, size_t *mapped)
614{
615 struct s390_domain *s390_domain = to_s390_domain(domain);
616 size_t size = pgcount << __ffs(pgsize);
617 int flags = ZPCI_PTE_VALID, rc = 0;
618
619 if (pgsize != SZ_4K)
620 return -EINVAL;
621
622 if (iova < s390_domain->domain.geometry.aperture_start ||
623 (iova + size - 1) > s390_domain->domain.geometry.aperture_end)
624 return -EINVAL;
625
626 if (!IS_ALIGNED(iova | paddr, pgsize))
627 return -EINVAL;
628
629 if (!(prot & IOMMU_WRITE))
630 flags |= ZPCI_TABLE_PROTECTED;
631
632 rc = s390_iommu_validate_trans(s390_domain, paddr, iova,
633 pgcount, flags, gfp);
634 if (!rc) {
635 *mapped = size;
636 atomic64_add(pgcount, &s390_domain->ctrs.mapped_pages);
637 }
638
639 return rc;
640}
641
642static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
643 dma_addr_t iova)
644{
645 struct s390_domain *s390_domain = to_s390_domain(domain);
646 unsigned long *rto, *sto, *pto;
647 unsigned long ste, pte, rte;
648 unsigned int rtx, sx, px;
649 phys_addr_t phys = 0;
650
651 if (iova < domain->geometry.aperture_start ||
652 iova > domain->geometry.aperture_end)
653 return 0;
654
655 rtx = calc_rtx(iova);
656 sx = calc_sx(iova);
657 px = calc_px(iova);
658 rto = s390_domain->dma_table;
659
660 rte = READ_ONCE(rto[rtx]);
661 if (reg_entry_isvalid(rte)) {
662 sto = get_rt_sto(rte);
663 ste = READ_ONCE(sto[sx]);
664 if (reg_entry_isvalid(ste)) {
665 pto = get_st_pto(ste);
666 pte = READ_ONCE(pto[px]);
667 if (pt_entry_isvalid(pte))
668 phys = pte & ZPCI_PTE_ADDR_MASK;
669 }
670 }
671
672 return phys;
673}
674
675static size_t s390_iommu_unmap_pages(struct iommu_domain *domain,
676 unsigned long iova,
677 size_t pgsize, size_t pgcount,
678 struct iommu_iotlb_gather *gather)
679{
680 struct s390_domain *s390_domain = to_s390_domain(domain);
681 size_t size = pgcount << __ffs(pgsize);
682 int rc;
683
684 if (WARN_ON(iova < s390_domain->domain.geometry.aperture_start ||
685 (iova + size - 1) > s390_domain->domain.geometry.aperture_end))
686 return 0;
687
688 rc = s390_iommu_invalidate_trans(s390_domain, iova, pgcount);
689 if (rc)
690 return 0;
691
692 iommu_iotlb_gather_add_range(gather, iova, size);
693 atomic64_add(pgcount, &s390_domain->ctrs.unmapped_pages);
694
695 return size;
696}
697
698static void s390_iommu_probe_finalize(struct device *dev)
699{
700 iommu_setup_dma_ops(dev, 0, U64_MAX);
701}
702
703struct zpci_iommu_ctrs *zpci_get_iommu_ctrs(struct zpci_dev *zdev)
704{
705 if (!zdev || !zdev->s390_domain)
706 return NULL;
707 return &zdev->s390_domain->ctrs;
708}
709
710int zpci_init_iommu(struct zpci_dev *zdev)
711{
712 u64 aperture_size;
713 int rc = 0;
714
715 rc = iommu_device_sysfs_add(&zdev->iommu_dev, NULL, NULL,
716 "s390-iommu.%08x", zdev->fid);
717 if (rc)
718 goto out_err;
719
720 rc = iommu_device_register(&zdev->iommu_dev, &s390_iommu_ops, NULL);
721 if (rc)
722 goto out_sysfs;
723
724 zdev->start_dma = PAGE_ALIGN(zdev->start_dma);
725 aperture_size = min3(s390_iommu_aperture,
726 ZPCI_TABLE_SIZE_RT - zdev->start_dma,
727 zdev->end_dma - zdev->start_dma + 1);
728 zdev->end_dma = zdev->start_dma + aperture_size - 1;
729
730 return 0;
731
732out_sysfs:
733 iommu_device_sysfs_remove(&zdev->iommu_dev);
734
735out_err:
736 return rc;
737}
738
739void zpci_destroy_iommu(struct zpci_dev *zdev)
740{
741 iommu_device_unregister(&zdev->iommu_dev);
742 iommu_device_sysfs_remove(&zdev->iommu_dev);
743}
744
745static int __init s390_iommu_setup(char *str)
746{
747 if (!strcmp(str, "strict")) {
748 pr_warn("s390_iommu=strict deprecated; use iommu.strict=1 instead\n");
749 iommu_set_dma_strict();
750 }
751 return 1;
752}
753
754__setup("s390_iommu=", s390_iommu_setup);
755
756static int __init s390_iommu_aperture_setup(char *str)
757{
758 if (kstrtou32(str, 10, &s390_iommu_aperture_factor))
759 s390_iommu_aperture_factor = 1;
760 return 1;
761}
762
763__setup("s390_iommu_aperture=", s390_iommu_aperture_setup);
764
765static int __init s390_iommu_init(void)
766{
767 int rc;
768
769 iommu_dma_forcedac = true;
770 s390_iommu_aperture = (u64)virt_to_phys(high_memory);
771 if (!s390_iommu_aperture_factor)
772 s390_iommu_aperture = ULONG_MAX;
773 else
774 s390_iommu_aperture *= s390_iommu_aperture_factor;
775
776 rc = dma_alloc_cpu_table_caches();
777 if (rc)
778 return rc;
779
780 return rc;
781}
782subsys_initcall(s390_iommu_init);
783
784static const struct iommu_ops s390_iommu_ops = {
785 .capable = s390_iommu_capable,
786 .domain_alloc_paging = s390_domain_alloc_paging,
787 .probe_device = s390_iommu_probe_device,
788 .probe_finalize = s390_iommu_probe_finalize,
789 .release_device = s390_iommu_release_device,
790 .device_group = generic_device_group,
791 .pgsize_bitmap = SZ_4K,
792 .get_resv_regions = s390_iommu_get_resv_regions,
793 .default_domain_ops = &(const struct iommu_domain_ops) {
794 .attach_dev = s390_iommu_attach_device,
795 .map_pages = s390_iommu_map_pages,
796 .unmap_pages = s390_iommu_unmap_pages,
797 .flush_iotlb_all = s390_iommu_flush_iotlb_all,
798 .iotlb_sync = s390_iommu_iotlb_sync,
799 .iotlb_sync_map = s390_iommu_iotlb_sync_map,
800 .iova_to_phys = s390_iommu_iova_to_phys,
801 .free = s390_domain_free,
802 }
803};
1/*
2 * IOMMU API for s390 PCI devices
3 *
4 * Copyright IBM Corp. 2015
5 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#include <linux/pci.h>
9#include <linux/iommu.h>
10#include <linux/iommu-helper.h>
11#include <linux/pci.h>
12#include <linux/sizes.h>
13#include <asm/pci_dma.h>
14
15/*
16 * Physically contiguous memory regions can be mapped with 4 KiB alignment,
17 * we allow all page sizes that are an order of 4KiB (no special large page
18 * support so far).
19 */
20#define S390_IOMMU_PGSIZES (~0xFFFUL)
21
22struct s390_domain {
23 struct iommu_domain domain;
24 struct list_head devices;
25 unsigned long *dma_table;
26 spinlock_t dma_table_lock;
27 spinlock_t list_lock;
28};
29
30struct s390_domain_device {
31 struct list_head list;
32 struct zpci_dev *zdev;
33};
34
35static struct s390_domain *to_s390_domain(struct iommu_domain *dom)
36{
37 return container_of(dom, struct s390_domain, domain);
38}
39
40static bool s390_iommu_capable(enum iommu_cap cap)
41{
42 switch (cap) {
43 case IOMMU_CAP_CACHE_COHERENCY:
44 return true;
45 case IOMMU_CAP_INTR_REMAP:
46 return true;
47 default:
48 return false;
49 }
50}
51
52static struct iommu_domain *s390_domain_alloc(unsigned domain_type)
53{
54 struct s390_domain *s390_domain;
55
56 if (domain_type != IOMMU_DOMAIN_UNMANAGED)
57 return NULL;
58
59 s390_domain = kzalloc(sizeof(*s390_domain), GFP_KERNEL);
60 if (!s390_domain)
61 return NULL;
62
63 s390_domain->dma_table = dma_alloc_cpu_table();
64 if (!s390_domain->dma_table) {
65 kfree(s390_domain);
66 return NULL;
67 }
68
69 spin_lock_init(&s390_domain->dma_table_lock);
70 spin_lock_init(&s390_domain->list_lock);
71 INIT_LIST_HEAD(&s390_domain->devices);
72
73 return &s390_domain->domain;
74}
75
76static void s390_domain_free(struct iommu_domain *domain)
77{
78 struct s390_domain *s390_domain = to_s390_domain(domain);
79
80 dma_cleanup_tables(s390_domain->dma_table);
81 kfree(s390_domain);
82}
83
84static int s390_iommu_attach_device(struct iommu_domain *domain,
85 struct device *dev)
86{
87 struct s390_domain *s390_domain = to_s390_domain(domain);
88 struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
89 struct s390_domain_device *domain_device;
90 unsigned long flags;
91 int rc;
92
93 if (!zdev)
94 return -ENODEV;
95
96 domain_device = kzalloc(sizeof(*domain_device), GFP_KERNEL);
97 if (!domain_device)
98 return -ENOMEM;
99
100 if (zdev->dma_table)
101 zpci_dma_exit_device(zdev);
102
103 zdev->dma_table = s390_domain->dma_table;
104 rc = zpci_register_ioat(zdev, 0, zdev->start_dma + PAGE_OFFSET,
105 zdev->start_dma + zdev->iommu_size - 1,
106 (u64) zdev->dma_table);
107 if (rc)
108 goto out_restore;
109
110 spin_lock_irqsave(&s390_domain->list_lock, flags);
111 /* First device defines the DMA range limits */
112 if (list_empty(&s390_domain->devices)) {
113 domain->geometry.aperture_start = zdev->start_dma;
114 domain->geometry.aperture_end = zdev->end_dma;
115 domain->geometry.force_aperture = true;
116 /* Allow only devices with identical DMA range limits */
117 } else if (domain->geometry.aperture_start != zdev->start_dma ||
118 domain->geometry.aperture_end != zdev->end_dma) {
119 rc = -EINVAL;
120 spin_unlock_irqrestore(&s390_domain->list_lock, flags);
121 goto out_restore;
122 }
123 domain_device->zdev = zdev;
124 zdev->s390_domain = s390_domain;
125 list_add(&domain_device->list, &s390_domain->devices);
126 spin_unlock_irqrestore(&s390_domain->list_lock, flags);
127
128 return 0;
129
130out_restore:
131 zpci_dma_init_device(zdev);
132 kfree(domain_device);
133
134 return rc;
135}
136
137static void s390_iommu_detach_device(struct iommu_domain *domain,
138 struct device *dev)
139{
140 struct s390_domain *s390_domain = to_s390_domain(domain);
141 struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
142 struct s390_domain_device *domain_device, *tmp;
143 unsigned long flags;
144 int found = 0;
145
146 if (!zdev)
147 return;
148
149 spin_lock_irqsave(&s390_domain->list_lock, flags);
150 list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
151 list) {
152 if (domain_device->zdev == zdev) {
153 list_del(&domain_device->list);
154 kfree(domain_device);
155 found = 1;
156 break;
157 }
158 }
159 spin_unlock_irqrestore(&s390_domain->list_lock, flags);
160
161 if (found) {
162 zdev->s390_domain = NULL;
163 zpci_unregister_ioat(zdev, 0);
164 zpci_dma_init_device(zdev);
165 }
166}
167
168static int s390_iommu_add_device(struct device *dev)
169{
170 struct iommu_group *group;
171 int rc;
172
173 group = iommu_group_get(dev);
174 if (!group) {
175 group = iommu_group_alloc();
176 if (IS_ERR(group))
177 return PTR_ERR(group);
178 }
179
180 rc = iommu_group_add_device(group, dev);
181 iommu_group_put(group);
182
183 return rc;
184}
185
186static void s390_iommu_remove_device(struct device *dev)
187{
188 struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;
189 struct iommu_domain *domain;
190
191 /*
192 * This is a workaround for a scenario where the IOMMU API common code
193 * "forgets" to call the detach_dev callback: After binding a device
194 * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers
195 * the attach_dev), removing the device via
196 * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev,
197 * only remove_device will be called via the BUS_NOTIFY_REMOVED_DEVICE
198 * notifier.
199 *
200 * So let's call detach_dev from here if it hasn't been called before.
201 */
202 if (zdev && zdev->s390_domain) {
203 domain = iommu_get_domain_for_dev(dev);
204 if (domain)
205 s390_iommu_detach_device(domain, dev);
206 }
207
208 iommu_group_remove_device(dev);
209}
210
211static int s390_iommu_update_trans(struct s390_domain *s390_domain,
212 unsigned long pa, dma_addr_t dma_addr,
213 size_t size, int flags)
214{
215 struct s390_domain_device *domain_device;
216 u8 *page_addr = (u8 *) (pa & PAGE_MASK);
217 dma_addr_t start_dma_addr = dma_addr;
218 unsigned long irq_flags, nr_pages, i;
219 unsigned long *entry;
220 int rc = 0;
221
222 if (dma_addr < s390_domain->domain.geometry.aperture_start ||
223 dma_addr + size > s390_domain->domain.geometry.aperture_end)
224 return -EINVAL;
225
226 nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
227 if (!nr_pages)
228 return 0;
229
230 spin_lock_irqsave(&s390_domain->dma_table_lock, irq_flags);
231 for (i = 0; i < nr_pages; i++) {
232 entry = dma_walk_cpu_trans(s390_domain->dma_table, dma_addr);
233 if (!entry) {
234 rc = -ENOMEM;
235 goto undo_cpu_trans;
236 }
237 dma_update_cpu_trans(entry, page_addr, flags);
238 page_addr += PAGE_SIZE;
239 dma_addr += PAGE_SIZE;
240 }
241
242 spin_lock(&s390_domain->list_lock);
243 list_for_each_entry(domain_device, &s390_domain->devices, list) {
244 rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32,
245 start_dma_addr, nr_pages * PAGE_SIZE);
246 if (rc)
247 break;
248 }
249 spin_unlock(&s390_domain->list_lock);
250
251undo_cpu_trans:
252 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
253 flags = ZPCI_PTE_INVALID;
254 while (i-- > 0) {
255 page_addr -= PAGE_SIZE;
256 dma_addr -= PAGE_SIZE;
257 entry = dma_walk_cpu_trans(s390_domain->dma_table,
258 dma_addr);
259 if (!entry)
260 break;
261 dma_update_cpu_trans(entry, page_addr, flags);
262 }
263 }
264 spin_unlock_irqrestore(&s390_domain->dma_table_lock, irq_flags);
265
266 return rc;
267}
268
269static int s390_iommu_map(struct iommu_domain *domain, unsigned long iova,
270 phys_addr_t paddr, size_t size, int prot)
271{
272 struct s390_domain *s390_domain = to_s390_domain(domain);
273 int flags = ZPCI_PTE_VALID, rc = 0;
274
275 if (!(prot & IOMMU_READ))
276 return -EINVAL;
277
278 if (!(prot & IOMMU_WRITE))
279 flags |= ZPCI_TABLE_PROTECTED;
280
281 rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
282 size, flags);
283
284 return rc;
285}
286
287static phys_addr_t s390_iommu_iova_to_phys(struct iommu_domain *domain,
288 dma_addr_t iova)
289{
290 struct s390_domain *s390_domain = to_s390_domain(domain);
291 unsigned long *sto, *pto, *rto, flags;
292 unsigned int rtx, sx, px;
293 phys_addr_t phys = 0;
294
295 if (iova < domain->geometry.aperture_start ||
296 iova > domain->geometry.aperture_end)
297 return 0;
298
299 rtx = calc_rtx(iova);
300 sx = calc_sx(iova);
301 px = calc_px(iova);
302 rto = s390_domain->dma_table;
303
304 spin_lock_irqsave(&s390_domain->dma_table_lock, flags);
305 if (rto && reg_entry_isvalid(rto[rtx])) {
306 sto = get_rt_sto(rto[rtx]);
307 if (sto && reg_entry_isvalid(sto[sx])) {
308 pto = get_st_pto(sto[sx]);
309 if (pto && pt_entry_isvalid(pto[px]))
310 phys = pto[px] & ZPCI_PTE_ADDR_MASK;
311 }
312 }
313 spin_unlock_irqrestore(&s390_domain->dma_table_lock, flags);
314
315 return phys;
316}
317
318static size_t s390_iommu_unmap(struct iommu_domain *domain,
319 unsigned long iova, size_t size)
320{
321 struct s390_domain *s390_domain = to_s390_domain(domain);
322 int flags = ZPCI_PTE_INVALID;
323 phys_addr_t paddr;
324 int rc;
325
326 paddr = s390_iommu_iova_to_phys(domain, iova);
327 if (!paddr)
328 return 0;
329
330 rc = s390_iommu_update_trans(s390_domain, (unsigned long) paddr, iova,
331 size, flags);
332 if (rc)
333 return 0;
334
335 return size;
336}
337
338static struct iommu_ops s390_iommu_ops = {
339 .capable = s390_iommu_capable,
340 .domain_alloc = s390_domain_alloc,
341 .domain_free = s390_domain_free,
342 .attach_dev = s390_iommu_attach_device,
343 .detach_dev = s390_iommu_detach_device,
344 .map = s390_iommu_map,
345 .unmap = s390_iommu_unmap,
346 .iova_to_phys = s390_iommu_iova_to_phys,
347 .add_device = s390_iommu_add_device,
348 .remove_device = s390_iommu_remove_device,
349 .pgsize_bitmap = S390_IOMMU_PGSIZES,
350};
351
352static int __init s390_iommu_init(void)
353{
354 return bus_set_iommu(&pci_bus_type, &s390_iommu_ops);
355}
356subsys_initcall(s390_iommu_init);