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