1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright IBM Corp. 2012
4 *
5 * Author(s):
6 * Jan Glauber <jang@linux.vnet.ibm.com>
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/export.h>
12 #include <linux/iommu-helper.h>
13 #include <linux/dma-map-ops.h>
14 #include <linux/vmalloc.h>
15 #include <linux/pci.h>
16 #include <asm/pci_dma.h>
17
18 static struct kmem_cache *dma_region_table_cache;
19 static struct kmem_cache *dma_page_table_cache;
20 static int s390_iommu_strict;
21 static u64 s390_iommu_aperture;
22 static u32 s390_iommu_aperture_factor = 1;
23
zpci_refresh_global(struct zpci_dev * zdev)24 static int zpci_refresh_global(struct zpci_dev *zdev)
25 {
26 return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
27 zdev->iommu_pages * PAGE_SIZE);
28 }
29
dma_alloc_cpu_table(gfp_t gfp)30 unsigned long *dma_alloc_cpu_table(gfp_t gfp)
31 {
32 unsigned long *table, *entry;
33
34 table = kmem_cache_alloc(dma_region_table_cache, gfp);
35 if (!table)
36 return NULL;
37
38 for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
39 *entry = ZPCI_TABLE_INVALID;
40 return table;
41 }
42
dma_free_cpu_table(void * table)43 static void dma_free_cpu_table(void *table)
44 {
45 kmem_cache_free(dma_region_table_cache, table);
46 }
47
dma_alloc_page_table(gfp_t gfp)48 static unsigned long *dma_alloc_page_table(gfp_t gfp)
49 {
50 unsigned long *table, *entry;
51
52 table = kmem_cache_alloc(dma_page_table_cache, gfp);
53 if (!table)
54 return NULL;
55
56 for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
57 *entry = ZPCI_PTE_INVALID;
58 return table;
59 }
60
dma_free_page_table(void * table)61 static void dma_free_page_table(void *table)
62 {
63 kmem_cache_free(dma_page_table_cache, table);
64 }
65
dma_get_seg_table_origin(unsigned long * rtep,gfp_t gfp)66 static unsigned long *dma_get_seg_table_origin(unsigned long *rtep, gfp_t gfp)
67 {
68 unsigned long old_rte, rte;
69 unsigned long *sto;
70
71 rte = READ_ONCE(*rtep);
72 if (reg_entry_isvalid(rte)) {
73 sto = get_rt_sto(rte);
74 } else {
75 sto = dma_alloc_cpu_table(gfp);
76 if (!sto)
77 return NULL;
78
79 set_rt_sto(&rte, virt_to_phys(sto));
80 validate_rt_entry(&rte);
81 entry_clr_protected(&rte);
82
83 old_rte = cmpxchg(rtep, ZPCI_TABLE_INVALID, rte);
84 if (old_rte != ZPCI_TABLE_INVALID) {
85 /* Somone else was faster, use theirs */
86 dma_free_cpu_table(sto);
87 sto = get_rt_sto(old_rte);
88 }
89 }
90 return sto;
91 }
92
dma_get_page_table_origin(unsigned long * step,gfp_t gfp)93 static unsigned long *dma_get_page_table_origin(unsigned long *step, gfp_t gfp)
94 {
95 unsigned long old_ste, ste;
96 unsigned long *pto;
97
98 ste = READ_ONCE(*step);
99 if (reg_entry_isvalid(ste)) {
100 pto = get_st_pto(ste);
101 } else {
102 pto = dma_alloc_page_table(gfp);
103 if (!pto)
104 return NULL;
105 set_st_pto(&ste, virt_to_phys(pto));
106 validate_st_entry(&ste);
107 entry_clr_protected(&ste);
108
109 old_ste = cmpxchg(step, ZPCI_TABLE_INVALID, ste);
110 if (old_ste != ZPCI_TABLE_INVALID) {
111 /* Somone else was faster, use theirs */
112 dma_free_page_table(pto);
113 pto = get_st_pto(old_ste);
114 }
115 }
116 return pto;
117 }
118
dma_walk_cpu_trans(unsigned long * rto,dma_addr_t dma_addr,gfp_t gfp)119 unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr,
120 gfp_t gfp)
121 {
122 unsigned long *sto, *pto;
123 unsigned int rtx, sx, px;
124
125 rtx = calc_rtx(dma_addr);
126 sto = dma_get_seg_table_origin(&rto[rtx], gfp);
127 if (!sto)
128 return NULL;
129
130 sx = calc_sx(dma_addr);
131 pto = dma_get_page_table_origin(&sto[sx], gfp);
132 if (!pto)
133 return NULL;
134
135 px = calc_px(dma_addr);
136 return &pto[px];
137 }
138
dma_update_cpu_trans(unsigned long * ptep,phys_addr_t page_addr,int flags)139 void dma_update_cpu_trans(unsigned long *ptep, phys_addr_t page_addr, int flags)
140 {
141 unsigned long pte;
142
143 pte = READ_ONCE(*ptep);
144 if (flags & ZPCI_PTE_INVALID) {
145 invalidate_pt_entry(&pte);
146 } else {
147 set_pt_pfaa(&pte, page_addr);
148 validate_pt_entry(&pte);
149 }
150
151 if (flags & ZPCI_TABLE_PROTECTED)
152 entry_set_protected(&pte);
153 else
154 entry_clr_protected(&pte);
155
156 xchg(ptep, pte);
157 }
158
__dma_update_trans(struct zpci_dev * zdev,phys_addr_t pa,dma_addr_t dma_addr,size_t size,int flags)159 static int __dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa,
160 dma_addr_t dma_addr, size_t size, int flags)
161 {
162 unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
163 phys_addr_t page_addr = (pa & PAGE_MASK);
164 unsigned long *entry;
165 int i, rc = 0;
166
167 if (!nr_pages)
168 return -EINVAL;
169
170 if (!zdev->dma_table)
171 return -EINVAL;
172
173 for (i = 0; i < nr_pages; i++) {
174 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr,
175 GFP_ATOMIC);
176 if (!entry) {
177 rc = -ENOMEM;
178 goto undo_cpu_trans;
179 }
180 dma_update_cpu_trans(entry, page_addr, flags);
181 page_addr += PAGE_SIZE;
182 dma_addr += PAGE_SIZE;
183 }
184
185 undo_cpu_trans:
186 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
187 flags = ZPCI_PTE_INVALID;
188 while (i-- > 0) {
189 page_addr -= PAGE_SIZE;
190 dma_addr -= PAGE_SIZE;
191 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr,
192 GFP_ATOMIC);
193 if (!entry)
194 break;
195 dma_update_cpu_trans(entry, page_addr, flags);
196 }
197 }
198 return rc;
199 }
200
__dma_purge_tlb(struct zpci_dev * zdev,dma_addr_t dma_addr,size_t size,int flags)201 static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
202 size_t size, int flags)
203 {
204 unsigned long irqflags;
205 int ret;
206
207 /*
208 * With zdev->tlb_refresh == 0, rpcit is not required to establish new
209 * translations when previously invalid translation-table entries are
210 * validated. With lazy unmap, rpcit is skipped for previously valid
211 * entries, but a global rpcit is then required before any address can
212 * be re-used, i.e. after each iommu bitmap wrap-around.
213 */
214 if ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID) {
215 if (!zdev->tlb_refresh)
216 return 0;
217 } else {
218 if (!s390_iommu_strict)
219 return 0;
220 }
221
222 ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
223 PAGE_ALIGN(size));
224 if (ret == -ENOMEM && !s390_iommu_strict) {
225 /* enable the hypervisor to free some resources */
226 if (zpci_refresh_global(zdev))
227 goto out;
228
229 spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags);
230 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
231 zdev->lazy_bitmap, zdev->iommu_pages);
232 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
233 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags);
234 ret = 0;
235 }
236 out:
237 return ret;
238 }
239
dma_update_trans(struct zpci_dev * zdev,phys_addr_t pa,dma_addr_t dma_addr,size_t size,int flags)240 static int dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa,
241 dma_addr_t dma_addr, size_t size, int flags)
242 {
243 int rc;
244
245 rc = __dma_update_trans(zdev, pa, dma_addr, size, flags);
246 if (rc)
247 return rc;
248
249 rc = __dma_purge_tlb(zdev, dma_addr, size, flags);
250 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
251 __dma_update_trans(zdev, pa, dma_addr, size, ZPCI_PTE_INVALID);
252
253 return rc;
254 }
255
dma_free_seg_table(unsigned long entry)256 void dma_free_seg_table(unsigned long entry)
257 {
258 unsigned long *sto = get_rt_sto(entry);
259 int sx;
260
261 for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
262 if (reg_entry_isvalid(sto[sx]))
263 dma_free_page_table(get_st_pto(sto[sx]));
264
265 dma_free_cpu_table(sto);
266 }
267
dma_cleanup_tables(unsigned long * table)268 void dma_cleanup_tables(unsigned long *table)
269 {
270 int rtx;
271
272 if (!table)
273 return;
274
275 for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
276 if (reg_entry_isvalid(table[rtx]))
277 dma_free_seg_table(table[rtx]);
278
279 dma_free_cpu_table(table);
280 }
281
__dma_alloc_iommu(struct device * dev,unsigned long start,int size)282 static unsigned long __dma_alloc_iommu(struct device *dev,
283 unsigned long start, int size)
284 {
285 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
286
287 return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
288 start, size, zdev->start_dma >> PAGE_SHIFT,
289 dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT),
290 0);
291 }
292
dma_alloc_address(struct device * dev,int size)293 static dma_addr_t dma_alloc_address(struct device *dev, int size)
294 {
295 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
296 unsigned long offset, flags;
297
298 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
299 offset = __dma_alloc_iommu(dev, zdev->next_bit, size);
300 if (offset == -1) {
301 if (!s390_iommu_strict) {
302 /* global flush before DMA addresses are reused */
303 if (zpci_refresh_global(zdev))
304 goto out_error;
305
306 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
307 zdev->lazy_bitmap, zdev->iommu_pages);
308 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
309 }
310 /* wrap-around */
311 offset = __dma_alloc_iommu(dev, 0, size);
312 if (offset == -1)
313 goto out_error;
314 }
315 zdev->next_bit = offset + size;
316 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
317
318 return zdev->start_dma + offset * PAGE_SIZE;
319
320 out_error:
321 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
322 return DMA_MAPPING_ERROR;
323 }
324
dma_free_address(struct device * dev,dma_addr_t dma_addr,int size)325 static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size)
326 {
327 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
328 unsigned long flags, offset;
329
330 offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
331
332 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
333 if (!zdev->iommu_bitmap)
334 goto out;
335
336 if (s390_iommu_strict)
337 bitmap_clear(zdev->iommu_bitmap, offset, size);
338 else
339 bitmap_set(zdev->lazy_bitmap, offset, size);
340
341 out:
342 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
343 }
344
zpci_err_dma(unsigned long rc,unsigned long addr)345 static inline void zpci_err_dma(unsigned long rc, unsigned long addr)
346 {
347 struct {
348 unsigned long rc;
349 unsigned long addr;
350 } __packed data = {rc, addr};
351
352 zpci_err_hex(&data, sizeof(data));
353 }
354
s390_dma_map_pages(struct device * dev,struct page * page,unsigned long offset,size_t size,enum dma_data_direction direction,unsigned long attrs)355 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
356 unsigned long offset, size_t size,
357 enum dma_data_direction direction,
358 unsigned long attrs)
359 {
360 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
361 unsigned long pa = page_to_phys(page) + offset;
362 int flags = ZPCI_PTE_VALID;
363 unsigned long nr_pages;
364 dma_addr_t dma_addr;
365 int ret;
366
367 /* This rounds up number of pages based on size and offset */
368 nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
369 dma_addr = dma_alloc_address(dev, nr_pages);
370 if (dma_addr == DMA_MAPPING_ERROR) {
371 ret = -ENOSPC;
372 goto out_err;
373 }
374
375 /* Use rounded up size */
376 size = nr_pages * PAGE_SIZE;
377
378 if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
379 flags |= ZPCI_TABLE_PROTECTED;
380
381 ret = dma_update_trans(zdev, pa, dma_addr, size, flags);
382 if (ret)
383 goto out_free;
384
385 atomic64_add(nr_pages, &zdev->mapped_pages);
386 return dma_addr + (offset & ~PAGE_MASK);
387
388 out_free:
389 dma_free_address(dev, dma_addr, nr_pages);
390 out_err:
391 zpci_err("map error:\n");
392 zpci_err_dma(ret, pa);
393 return DMA_MAPPING_ERROR;
394 }
395
s390_dma_unmap_pages(struct device * dev,dma_addr_t dma_addr,size_t size,enum dma_data_direction direction,unsigned long attrs)396 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
397 size_t size, enum dma_data_direction direction,
398 unsigned long attrs)
399 {
400 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
401 int npages, ret;
402
403 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
404 dma_addr = dma_addr & PAGE_MASK;
405 ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
406 ZPCI_PTE_INVALID);
407 if (ret) {
408 zpci_err("unmap error:\n");
409 zpci_err_dma(ret, dma_addr);
410 return;
411 }
412
413 atomic64_add(npages, &zdev->unmapped_pages);
414 dma_free_address(dev, dma_addr, npages);
415 }
416
s390_dma_alloc(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t flag,unsigned long attrs)417 static void *s390_dma_alloc(struct device *dev, size_t size,
418 dma_addr_t *dma_handle, gfp_t flag,
419 unsigned long attrs)
420 {
421 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
422 struct page *page;
423 phys_addr_t pa;
424 dma_addr_t map;
425
426 size = PAGE_ALIGN(size);
427 page = alloc_pages(flag | __GFP_ZERO, get_order(size));
428 if (!page)
429 return NULL;
430
431 pa = page_to_phys(page);
432 map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0);
433 if (dma_mapping_error(dev, map)) {
434 __free_pages(page, get_order(size));
435 return NULL;
436 }
437
438 atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
439 if (dma_handle)
440 *dma_handle = map;
441 return phys_to_virt(pa);
442 }
443
s390_dma_free(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle,unsigned long attrs)444 static void s390_dma_free(struct device *dev, size_t size,
445 void *vaddr, dma_addr_t dma_handle,
446 unsigned long attrs)
447 {
448 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
449
450 size = PAGE_ALIGN(size);
451 atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
452 s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0);
453 free_pages((unsigned long)vaddr, get_order(size));
454 }
455
456 /* Map a segment into a contiguous dma address area */
__s390_dma_map_sg(struct device * dev,struct scatterlist * sg,size_t size,dma_addr_t * handle,enum dma_data_direction dir)457 static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
458 size_t size, dma_addr_t *handle,
459 enum dma_data_direction dir)
460 {
461 unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
462 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
463 dma_addr_t dma_addr_base, dma_addr;
464 int flags = ZPCI_PTE_VALID;
465 struct scatterlist *s;
466 phys_addr_t pa = 0;
467 int ret;
468
469 dma_addr_base = dma_alloc_address(dev, nr_pages);
470 if (dma_addr_base == DMA_MAPPING_ERROR)
471 return -ENOMEM;
472
473 dma_addr = dma_addr_base;
474 if (dir == DMA_NONE || dir == DMA_TO_DEVICE)
475 flags |= ZPCI_TABLE_PROTECTED;
476
477 for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) {
478 pa = page_to_phys(sg_page(s));
479 ret = __dma_update_trans(zdev, pa, dma_addr,
480 s->offset + s->length, flags);
481 if (ret)
482 goto unmap;
483
484 dma_addr += s->offset + s->length;
485 }
486 ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags);
487 if (ret)
488 goto unmap;
489
490 *handle = dma_addr_base;
491 atomic64_add(nr_pages, &zdev->mapped_pages);
492
493 return ret;
494
495 unmap:
496 dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base,
497 ZPCI_PTE_INVALID);
498 dma_free_address(dev, dma_addr_base, nr_pages);
499 zpci_err("map error:\n");
500 zpci_err_dma(ret, pa);
501 return ret;
502 }
503
s390_dma_map_sg(struct device * dev,struct scatterlist * sg,int nr_elements,enum dma_data_direction dir,unsigned long attrs)504 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
505 int nr_elements, enum dma_data_direction dir,
506 unsigned long attrs)
507 {
508 struct scatterlist *s = sg, *start = sg, *dma = sg;
509 unsigned int max = dma_get_max_seg_size(dev);
510 unsigned int size = s->offset + s->length;
511 unsigned int offset = s->offset;
512 int count = 0, i, ret;
513
514 for (i = 1; i < nr_elements; i++) {
515 s = sg_next(s);
516
517 s->dma_length = 0;
518
519 if (s->offset || (size & ~PAGE_MASK) ||
520 size + s->length > max) {
521 ret = __s390_dma_map_sg(dev, start, size,
522 &dma->dma_address, dir);
523 if (ret)
524 goto unmap;
525
526 dma->dma_address += offset;
527 dma->dma_length = size - offset;
528
529 size = offset = s->offset;
530 start = s;
531 dma = sg_next(dma);
532 count++;
533 }
534 size += s->length;
535 }
536 ret = __s390_dma_map_sg(dev, start, size, &dma->dma_address, dir);
537 if (ret)
538 goto unmap;
539
540 dma->dma_address += offset;
541 dma->dma_length = size - offset;
542
543 return count + 1;
544 unmap:
545 for_each_sg(sg, s, count, i)
546 s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
547 dir, attrs);
548
549 return ret;
550 }
551
s390_dma_unmap_sg(struct device * dev,struct scatterlist * sg,int nr_elements,enum dma_data_direction dir,unsigned long attrs)552 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
553 int nr_elements, enum dma_data_direction dir,
554 unsigned long attrs)
555 {
556 struct scatterlist *s;
557 int i;
558
559 for_each_sg(sg, s, nr_elements, i) {
560 if (s->dma_length)
561 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
562 dir, attrs);
563 s->dma_address = 0;
564 s->dma_length = 0;
565 }
566 }
567
bitmap_vzalloc(size_t bits,gfp_t flags)568 static unsigned long *bitmap_vzalloc(size_t bits, gfp_t flags)
569 {
570 size_t n = BITS_TO_LONGS(bits);
571 size_t bytes;
572
573 if (unlikely(check_mul_overflow(n, sizeof(unsigned long), &bytes)))
574 return NULL;
575
576 return vzalloc(bytes);
577 }
578
zpci_dma_init_device(struct zpci_dev * zdev)579 int zpci_dma_init_device(struct zpci_dev *zdev)
580 {
581 u8 status;
582 int rc;
583
584 /*
585 * At this point, if the device is part of an IOMMU domain, this would
586 * be a strong hint towards a bug in the IOMMU API (common) code and/or
587 * simultaneous access via IOMMU and DMA API. So let's issue a warning.
588 */
589 WARN_ON(zdev->s390_domain);
590
591 spin_lock_init(&zdev->iommu_bitmap_lock);
592
593 zdev->dma_table = dma_alloc_cpu_table(GFP_KERNEL);
594 if (!zdev->dma_table) {
595 rc = -ENOMEM;
596 goto out;
597 }
598
599 /*
600 * Restrict the iommu bitmap size to the minimum of the following:
601 * - s390_iommu_aperture which defaults to high_memory
602 * - 3-level pagetable address limit minus start_dma offset
603 * - DMA address range allowed by the hardware (clp query pci fn)
604 *
605 * Also set zdev->end_dma to the actual end address of the usable
606 * range, instead of the theoretical maximum as reported by hardware.
607 *
608 * This limits the number of concurrently usable DMA mappings since
609 * for each DMA mapped memory address we need a DMA address including
610 * extra DMA addresses for multiple mappings of the same memory address.
611 */
612 zdev->start_dma = PAGE_ALIGN(zdev->start_dma);
613 zdev->iommu_size = min3(s390_iommu_aperture,
614 ZPCI_TABLE_SIZE_RT - zdev->start_dma,
615 zdev->end_dma - zdev->start_dma + 1);
616 zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
617 zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
618 zdev->iommu_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL);
619 if (!zdev->iommu_bitmap) {
620 rc = -ENOMEM;
621 goto free_dma_table;
622 }
623 if (!s390_iommu_strict) {
624 zdev->lazy_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL);
625 if (!zdev->lazy_bitmap) {
626 rc = -ENOMEM;
627 goto free_bitmap;
628 }
629
630 }
631 if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
632 virt_to_phys(zdev->dma_table), &status)) {
633 rc = -EIO;
634 goto free_bitmap;
635 }
636
637 return 0;
638 free_bitmap:
639 vfree(zdev->iommu_bitmap);
640 zdev->iommu_bitmap = NULL;
641 vfree(zdev->lazy_bitmap);
642 zdev->lazy_bitmap = NULL;
643 free_dma_table:
644 dma_free_cpu_table(zdev->dma_table);
645 zdev->dma_table = NULL;
646 out:
647 return rc;
648 }
649
zpci_dma_exit_device(struct zpci_dev * zdev)650 int zpci_dma_exit_device(struct zpci_dev *zdev)
651 {
652 int cc = 0;
653
654 /*
655 * At this point, if the device is part of an IOMMU domain, this would
656 * be a strong hint towards a bug in the IOMMU API (common) code and/or
657 * simultaneous access via IOMMU and DMA API. So let's issue a warning.
658 */
659 WARN_ON(zdev->s390_domain);
660 if (zdev_enabled(zdev))
661 cc = zpci_unregister_ioat(zdev, 0);
662 /*
663 * cc == 3 indicates the function is gone already. This can happen
664 * if the function was deconfigured/disabled suddenly and we have not
665 * received a new handle yet.
666 */
667 if (cc && cc != 3)
668 return -EIO;
669
670 dma_cleanup_tables(zdev->dma_table);
671 zdev->dma_table = NULL;
672 vfree(zdev->iommu_bitmap);
673 zdev->iommu_bitmap = NULL;
674 vfree(zdev->lazy_bitmap);
675 zdev->lazy_bitmap = NULL;
676 zdev->next_bit = 0;
677 return 0;
678 }
679
dma_alloc_cpu_table_caches(void)680 static int __init dma_alloc_cpu_table_caches(void)
681 {
682 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
683 ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
684 0, NULL);
685 if (!dma_region_table_cache)
686 return -ENOMEM;
687
688 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
689 ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
690 0, NULL);
691 if (!dma_page_table_cache) {
692 kmem_cache_destroy(dma_region_table_cache);
693 return -ENOMEM;
694 }
695 return 0;
696 }
697
zpci_dma_init(void)698 int __init zpci_dma_init(void)
699 {
700 s390_iommu_aperture = (u64)virt_to_phys(high_memory);
701 if (!s390_iommu_aperture_factor)
702 s390_iommu_aperture = ULONG_MAX;
703 else
704 s390_iommu_aperture *= s390_iommu_aperture_factor;
705
706 return dma_alloc_cpu_table_caches();
707 }
708
zpci_dma_exit(void)709 void zpci_dma_exit(void)
710 {
711 kmem_cache_destroy(dma_page_table_cache);
712 kmem_cache_destroy(dma_region_table_cache);
713 }
714
715 const struct dma_map_ops s390_pci_dma_ops = {
716 .alloc = s390_dma_alloc,
717 .free = s390_dma_free,
718 .map_sg = s390_dma_map_sg,
719 .unmap_sg = s390_dma_unmap_sg,
720 .map_page = s390_dma_map_pages,
721 .unmap_page = s390_dma_unmap_pages,
722 .mmap = dma_common_mmap,
723 .get_sgtable = dma_common_get_sgtable,
724 .alloc_pages = dma_common_alloc_pages,
725 .free_pages = dma_common_free_pages,
726 /* dma_supported is unconditionally true without a callback */
727 };
728 EXPORT_SYMBOL_GPL(s390_pci_dma_ops);
729
s390_iommu_setup(char * str)730 static int __init s390_iommu_setup(char *str)
731 {
732 if (!strcmp(str, "strict"))
733 s390_iommu_strict = 1;
734 return 1;
735 }
736
737 __setup("s390_iommu=", s390_iommu_setup);
738
s390_iommu_aperture_setup(char * str)739 static int __init s390_iommu_aperture_setup(char *str)
740 {
741 if (kstrtou32(str, 10, &s390_iommu_aperture_factor))
742 s390_iommu_aperture_factor = 1;
743 return 1;
744 }
745
746 __setup("s390_iommu_aperture=", s390_iommu_aperture_setup);
747