xref: /linux/arch/powerpc/kernel/iommu.c (revision 1e0731c05c985deb68a97fa44c1adcd3305dda90)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
4  *
5  * Rewrite, cleanup, new allocation schemes, virtual merging:
6  * Copyright (C) 2004 Olof Johansson, IBM Corporation
7  *               and  Ben. Herrenschmidt, IBM Corporation
8  *
9  * Dynamic DMA mapping support, bus-independent parts.
10  */
11 
12 
13 #include <linux/init.h>
14 #include <linux/types.h>
15 #include <linux/slab.h>
16 #include <linux/mm.h>
17 #include <linux/spinlock.h>
18 #include <linux/string.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/bitmap.h>
21 #include <linux/iommu-helper.h>
22 #include <linux/crash_dump.h>
23 #include <linux/hash.h>
24 #include <linux/fault-inject.h>
25 #include <linux/pci.h>
26 #include <linux/iommu.h>
27 #include <linux/sched.h>
28 #include <linux/debugfs.h>
29 #include <asm/io.h>
30 #include <asm/iommu.h>
31 #include <asm/pci-bridge.h>
32 #include <asm/machdep.h>
33 #include <asm/kdump.h>
34 #include <asm/fadump.h>
35 #include <asm/vio.h>
36 #include <asm/tce.h>
37 #include <asm/mmu_context.h>
38 #include <asm/ppc-pci.h>
39 
40 #define DBG(...)
41 
42 #ifdef CONFIG_IOMMU_DEBUGFS
43 static int iommu_debugfs_weight_get(void *data, u64 *val)
44 {
45 	struct iommu_table *tbl = data;
46 	*val = bitmap_weight(tbl->it_map, tbl->it_size);
47 	return 0;
48 }
49 DEFINE_DEBUGFS_ATTRIBUTE(iommu_debugfs_fops_weight, iommu_debugfs_weight_get, NULL, "%llu\n");
50 
51 static void iommu_debugfs_add(struct iommu_table *tbl)
52 {
53 	char name[10];
54 	struct dentry *liobn_entry;
55 
56 	sprintf(name, "%08lx", tbl->it_index);
57 	liobn_entry = debugfs_create_dir(name, iommu_debugfs_dir);
58 
59 	debugfs_create_file_unsafe("weight", 0400, liobn_entry, tbl, &iommu_debugfs_fops_weight);
60 	debugfs_create_ulong("it_size", 0400, liobn_entry, &tbl->it_size);
61 	debugfs_create_ulong("it_page_shift", 0400, liobn_entry, &tbl->it_page_shift);
62 	debugfs_create_ulong("it_reserved_start", 0400, liobn_entry, &tbl->it_reserved_start);
63 	debugfs_create_ulong("it_reserved_end", 0400, liobn_entry, &tbl->it_reserved_end);
64 	debugfs_create_ulong("it_indirect_levels", 0400, liobn_entry, &tbl->it_indirect_levels);
65 	debugfs_create_ulong("it_level_size", 0400, liobn_entry, &tbl->it_level_size);
66 }
67 
68 static void iommu_debugfs_del(struct iommu_table *tbl)
69 {
70 	char name[10];
71 
72 	sprintf(name, "%08lx", tbl->it_index);
73 	debugfs_lookup_and_remove(name, iommu_debugfs_dir);
74 }
75 #else
76 static void iommu_debugfs_add(struct iommu_table *tbl){}
77 static void iommu_debugfs_del(struct iommu_table *tbl){}
78 #endif
79 
80 static int novmerge;
81 
82 static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);
83 
84 static int __init setup_iommu(char *str)
85 {
86 	if (!strcmp(str, "novmerge"))
87 		novmerge = 1;
88 	else if (!strcmp(str, "vmerge"))
89 		novmerge = 0;
90 	return 1;
91 }
92 
93 __setup("iommu=", setup_iommu);
94 
95 static DEFINE_PER_CPU(unsigned int, iommu_pool_hash);
96 
97 /*
98  * We precalculate the hash to avoid doing it on every allocation.
99  *
100  * The hash is important to spread CPUs across all the pools. For example,
101  * on a POWER7 with 4 way SMT we want interrupts on the primary threads and
102  * with 4 pools all primary threads would map to the same pool.
103  */
104 static int __init setup_iommu_pool_hash(void)
105 {
106 	unsigned int i;
107 
108 	for_each_possible_cpu(i)
109 		per_cpu(iommu_pool_hash, i) = hash_32(i, IOMMU_POOL_HASHBITS);
110 
111 	return 0;
112 }
113 subsys_initcall(setup_iommu_pool_hash);
114 
115 #ifdef CONFIG_FAIL_IOMMU
116 
117 static DECLARE_FAULT_ATTR(fail_iommu);
118 
119 static int __init setup_fail_iommu(char *str)
120 {
121 	return setup_fault_attr(&fail_iommu, str);
122 }
123 __setup("fail_iommu=", setup_fail_iommu);
124 
125 static bool should_fail_iommu(struct device *dev)
126 {
127 	return dev->archdata.fail_iommu && should_fail(&fail_iommu, 1);
128 }
129 
130 static int __init fail_iommu_debugfs(void)
131 {
132 	struct dentry *dir = fault_create_debugfs_attr("fail_iommu",
133 						       NULL, &fail_iommu);
134 
135 	return PTR_ERR_OR_ZERO(dir);
136 }
137 late_initcall(fail_iommu_debugfs);
138 
139 static ssize_t fail_iommu_show(struct device *dev,
140 			       struct device_attribute *attr, char *buf)
141 {
142 	return sprintf(buf, "%d\n", dev->archdata.fail_iommu);
143 }
144 
145 static ssize_t fail_iommu_store(struct device *dev,
146 				struct device_attribute *attr, const char *buf,
147 				size_t count)
148 {
149 	int i;
150 
151 	if (count > 0 && sscanf(buf, "%d", &i) > 0)
152 		dev->archdata.fail_iommu = (i == 0) ? 0 : 1;
153 
154 	return count;
155 }
156 
157 static DEVICE_ATTR_RW(fail_iommu);
158 
159 static int fail_iommu_bus_notify(struct notifier_block *nb,
160 				 unsigned long action, void *data)
161 {
162 	struct device *dev = data;
163 
164 	if (action == BUS_NOTIFY_ADD_DEVICE) {
165 		if (device_create_file(dev, &dev_attr_fail_iommu))
166 			pr_warn("Unable to create IOMMU fault injection sysfs "
167 				"entries\n");
168 	} else if (action == BUS_NOTIFY_DEL_DEVICE) {
169 		device_remove_file(dev, &dev_attr_fail_iommu);
170 	}
171 
172 	return 0;
173 }
174 
175 /*
176  * PCI and VIO buses need separate notifier_block structs, since they're linked
177  * list nodes.  Sharing a notifier_block would mean that any notifiers later
178  * registered for PCI buses would also get called by VIO buses and vice versa.
179  */
180 static struct notifier_block fail_iommu_pci_bus_notifier = {
181 	.notifier_call = fail_iommu_bus_notify
182 };
183 
184 #ifdef CONFIG_IBMVIO
185 static struct notifier_block fail_iommu_vio_bus_notifier = {
186 	.notifier_call = fail_iommu_bus_notify
187 };
188 #endif
189 
190 static int __init fail_iommu_setup(void)
191 {
192 #ifdef CONFIG_PCI
193 	bus_register_notifier(&pci_bus_type, &fail_iommu_pci_bus_notifier);
194 #endif
195 #ifdef CONFIG_IBMVIO
196 	bus_register_notifier(&vio_bus_type, &fail_iommu_vio_bus_notifier);
197 #endif
198 
199 	return 0;
200 }
201 /*
202  * Must execute after PCI and VIO subsystem have initialised but before
203  * devices are probed.
204  */
205 arch_initcall(fail_iommu_setup);
206 #else
207 static inline bool should_fail_iommu(struct device *dev)
208 {
209 	return false;
210 }
211 #endif
212 
213 static unsigned long iommu_range_alloc(struct device *dev,
214 				       struct iommu_table *tbl,
215                                        unsigned long npages,
216                                        unsigned long *handle,
217                                        unsigned long mask,
218                                        unsigned int align_order)
219 {
220 	unsigned long n, end, start;
221 	unsigned long limit;
222 	int largealloc = npages > 15;
223 	int pass = 0;
224 	unsigned long align_mask;
225 	unsigned long flags;
226 	unsigned int pool_nr;
227 	struct iommu_pool *pool;
228 
229 	align_mask = (1ull << align_order) - 1;
230 
231 	/* This allocator was derived from x86_64's bit string search */
232 
233 	/* Sanity check */
234 	if (unlikely(npages == 0)) {
235 		if (printk_ratelimit())
236 			WARN_ON(1);
237 		return DMA_MAPPING_ERROR;
238 	}
239 
240 	if (should_fail_iommu(dev))
241 		return DMA_MAPPING_ERROR;
242 
243 	/*
244 	 * We don't need to disable preemption here because any CPU can
245 	 * safely use any IOMMU pool.
246 	 */
247 	pool_nr = raw_cpu_read(iommu_pool_hash) & (tbl->nr_pools - 1);
248 
249 	if (largealloc)
250 		pool = &(tbl->large_pool);
251 	else
252 		pool = &(tbl->pools[pool_nr]);
253 
254 	spin_lock_irqsave(&(pool->lock), flags);
255 
256 again:
257 	if ((pass == 0) && handle && *handle &&
258 	    (*handle >= pool->start) && (*handle < pool->end))
259 		start = *handle;
260 	else
261 		start = pool->hint;
262 
263 	limit = pool->end;
264 
265 	/* The case below can happen if we have a small segment appended
266 	 * to a large, or when the previous alloc was at the very end of
267 	 * the available space. If so, go back to the initial start.
268 	 */
269 	if (start >= limit)
270 		start = pool->start;
271 
272 	if (limit + tbl->it_offset > mask) {
273 		limit = mask - tbl->it_offset + 1;
274 		/* If we're constrained on address range, first try
275 		 * at the masked hint to avoid O(n) search complexity,
276 		 * but on second pass, start at 0 in pool 0.
277 		 */
278 		if ((start & mask) >= limit || pass > 0) {
279 			spin_unlock(&(pool->lock));
280 			pool = &(tbl->pools[0]);
281 			spin_lock(&(pool->lock));
282 			start = pool->start;
283 		} else {
284 			start &= mask;
285 		}
286 	}
287 
288 	n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset,
289 			dma_get_seg_boundary_nr_pages(dev, tbl->it_page_shift),
290 			align_mask);
291 	if (n == -1) {
292 		if (likely(pass == 0)) {
293 			/* First try the pool from the start */
294 			pool->hint = pool->start;
295 			pass++;
296 			goto again;
297 
298 		} else if (pass <= tbl->nr_pools) {
299 			/* Now try scanning all the other pools */
300 			spin_unlock(&(pool->lock));
301 			pool_nr = (pool_nr + 1) & (tbl->nr_pools - 1);
302 			pool = &tbl->pools[pool_nr];
303 			spin_lock(&(pool->lock));
304 			pool->hint = pool->start;
305 			pass++;
306 			goto again;
307 
308 		} else if (pass == tbl->nr_pools + 1) {
309 			/* Last resort: try largepool */
310 			spin_unlock(&pool->lock);
311 			pool = &tbl->large_pool;
312 			spin_lock(&pool->lock);
313 			pool->hint = pool->start;
314 			pass++;
315 			goto again;
316 
317 		} else {
318 			/* Give up */
319 			spin_unlock_irqrestore(&(pool->lock), flags);
320 			return DMA_MAPPING_ERROR;
321 		}
322 	}
323 
324 	end = n + npages;
325 
326 	/* Bump the hint to a new block for small allocs. */
327 	if (largealloc) {
328 		/* Don't bump to new block to avoid fragmentation */
329 		pool->hint = end;
330 	} else {
331 		/* Overflow will be taken care of at the next allocation */
332 		pool->hint = (end + tbl->it_blocksize - 1) &
333 		                ~(tbl->it_blocksize - 1);
334 	}
335 
336 	/* Update handle for SG allocations */
337 	if (handle)
338 		*handle = end;
339 
340 	spin_unlock_irqrestore(&(pool->lock), flags);
341 
342 	return n;
343 }
344 
345 static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
346 			      void *page, unsigned int npages,
347 			      enum dma_data_direction direction,
348 			      unsigned long mask, unsigned int align_order,
349 			      unsigned long attrs)
350 {
351 	unsigned long entry;
352 	dma_addr_t ret = DMA_MAPPING_ERROR;
353 	int build_fail;
354 
355 	entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order);
356 
357 	if (unlikely(entry == DMA_MAPPING_ERROR))
358 		return DMA_MAPPING_ERROR;
359 
360 	entry += tbl->it_offset;	/* Offset into real TCE table */
361 	ret = entry << tbl->it_page_shift;	/* Set the return dma address */
362 
363 	/* Put the TCEs in the HW table */
364 	build_fail = tbl->it_ops->set(tbl, entry, npages,
365 				      (unsigned long)page &
366 				      IOMMU_PAGE_MASK(tbl), direction, attrs);
367 
368 	/* tbl->it_ops->set() only returns non-zero for transient errors.
369 	 * Clean up the table bitmap in this case and return
370 	 * DMA_MAPPING_ERROR. For all other errors the functionality is
371 	 * not altered.
372 	 */
373 	if (unlikely(build_fail)) {
374 		__iommu_free(tbl, ret, npages);
375 		return DMA_MAPPING_ERROR;
376 	}
377 
378 	/* Flush/invalidate TLB caches if necessary */
379 	if (tbl->it_ops->flush)
380 		tbl->it_ops->flush(tbl);
381 
382 	/* Make sure updates are seen by hardware */
383 	mb();
384 
385 	return ret;
386 }
387 
388 static bool iommu_free_check(struct iommu_table *tbl, dma_addr_t dma_addr,
389 			     unsigned int npages)
390 {
391 	unsigned long entry, free_entry;
392 
393 	entry = dma_addr >> tbl->it_page_shift;
394 	free_entry = entry - tbl->it_offset;
395 
396 	if (((free_entry + npages) > tbl->it_size) ||
397 	    (entry < tbl->it_offset)) {
398 		if (printk_ratelimit()) {
399 			printk(KERN_INFO "iommu_free: invalid entry\n");
400 			printk(KERN_INFO "\tentry     = 0x%lx\n", entry);
401 			printk(KERN_INFO "\tdma_addr  = 0x%llx\n", (u64)dma_addr);
402 			printk(KERN_INFO "\tTable     = 0x%llx\n", (u64)tbl);
403 			printk(KERN_INFO "\tbus#      = 0x%llx\n", (u64)tbl->it_busno);
404 			printk(KERN_INFO "\tsize      = 0x%llx\n", (u64)tbl->it_size);
405 			printk(KERN_INFO "\tstartOff  = 0x%llx\n", (u64)tbl->it_offset);
406 			printk(KERN_INFO "\tindex     = 0x%llx\n", (u64)tbl->it_index);
407 			WARN_ON(1);
408 		}
409 
410 		return false;
411 	}
412 
413 	return true;
414 }
415 
416 static struct iommu_pool *get_pool(struct iommu_table *tbl,
417 				   unsigned long entry)
418 {
419 	struct iommu_pool *p;
420 	unsigned long largepool_start = tbl->large_pool.start;
421 
422 	/* The large pool is the last pool at the top of the table */
423 	if (entry >= largepool_start) {
424 		p = &tbl->large_pool;
425 	} else {
426 		unsigned int pool_nr = entry / tbl->poolsize;
427 
428 		BUG_ON(pool_nr > tbl->nr_pools);
429 		p = &tbl->pools[pool_nr];
430 	}
431 
432 	return p;
433 }
434 
435 static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
436 			 unsigned int npages)
437 {
438 	unsigned long entry, free_entry;
439 	unsigned long flags;
440 	struct iommu_pool *pool;
441 
442 	entry = dma_addr >> tbl->it_page_shift;
443 	free_entry = entry - tbl->it_offset;
444 
445 	pool = get_pool(tbl, free_entry);
446 
447 	if (!iommu_free_check(tbl, dma_addr, npages))
448 		return;
449 
450 	tbl->it_ops->clear(tbl, entry, npages);
451 
452 	spin_lock_irqsave(&(pool->lock), flags);
453 	bitmap_clear(tbl->it_map, free_entry, npages);
454 	spin_unlock_irqrestore(&(pool->lock), flags);
455 }
456 
457 static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
458 		unsigned int npages)
459 {
460 	__iommu_free(tbl, dma_addr, npages);
461 
462 	/* Make sure TLB cache is flushed if the HW needs it. We do
463 	 * not do an mb() here on purpose, it is not needed on any of
464 	 * the current platforms.
465 	 */
466 	if (tbl->it_ops->flush)
467 		tbl->it_ops->flush(tbl);
468 }
469 
470 int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl,
471 		     struct scatterlist *sglist, int nelems,
472 		     unsigned long mask, enum dma_data_direction direction,
473 		     unsigned long attrs)
474 {
475 	dma_addr_t dma_next = 0, dma_addr;
476 	struct scatterlist *s, *outs, *segstart;
477 	int outcount, incount, i, build_fail = 0;
478 	unsigned int align;
479 	unsigned long handle;
480 	unsigned int max_seg_size;
481 
482 	BUG_ON(direction == DMA_NONE);
483 
484 	if ((nelems == 0) || !tbl)
485 		return -EINVAL;
486 
487 	outs = s = segstart = &sglist[0];
488 	outcount = 1;
489 	incount = nelems;
490 	handle = 0;
491 
492 	/* Init first segment length for backout at failure */
493 	outs->dma_length = 0;
494 
495 	DBG("sg mapping %d elements:\n", nelems);
496 
497 	max_seg_size = dma_get_max_seg_size(dev);
498 	for_each_sg(sglist, s, nelems, i) {
499 		unsigned long vaddr, npages, entry, slen;
500 
501 		slen = s->length;
502 		/* Sanity check */
503 		if (slen == 0) {
504 			dma_next = 0;
505 			continue;
506 		}
507 		/* Allocate iommu entries for that segment */
508 		vaddr = (unsigned long) sg_virt(s);
509 		npages = iommu_num_pages(vaddr, slen, IOMMU_PAGE_SIZE(tbl));
510 		align = 0;
511 		if (tbl->it_page_shift < PAGE_SHIFT && slen >= PAGE_SIZE &&
512 		    (vaddr & ~PAGE_MASK) == 0)
513 			align = PAGE_SHIFT - tbl->it_page_shift;
514 		entry = iommu_range_alloc(dev, tbl, npages, &handle,
515 					  mask >> tbl->it_page_shift, align);
516 
517 		DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
518 
519 		/* Handle failure */
520 		if (unlikely(entry == DMA_MAPPING_ERROR)) {
521 			if (!(attrs & DMA_ATTR_NO_WARN) &&
522 			    printk_ratelimit())
523 				dev_info(dev, "iommu_alloc failed, tbl %p "
524 					 "vaddr %lx npages %lu\n", tbl, vaddr,
525 					 npages);
526 			goto failure;
527 		}
528 
529 		/* Convert entry to a dma_addr_t */
530 		entry += tbl->it_offset;
531 		dma_addr = entry << tbl->it_page_shift;
532 		dma_addr |= (vaddr & ~IOMMU_PAGE_MASK(tbl));
533 
534 		DBG("  - %lu pages, entry: %lx, dma_addr: %lx\n",
535 			    npages, entry, dma_addr);
536 
537 		/* Insert into HW table */
538 		build_fail = tbl->it_ops->set(tbl, entry, npages,
539 					      vaddr & IOMMU_PAGE_MASK(tbl),
540 					      direction, attrs);
541 		if(unlikely(build_fail))
542 			goto failure;
543 
544 		/* If we are in an open segment, try merging */
545 		if (segstart != s) {
546 			DBG("  - trying merge...\n");
547 			/* We cannot merge if:
548 			 * - allocated dma_addr isn't contiguous to previous allocation
549 			 */
550 			if (novmerge || (dma_addr != dma_next) ||
551 			    (outs->dma_length + s->length > max_seg_size)) {
552 				/* Can't merge: create a new segment */
553 				segstart = s;
554 				outcount++;
555 				outs = sg_next(outs);
556 				DBG("    can't merge, new segment.\n");
557 			} else {
558 				outs->dma_length += s->length;
559 				DBG("    merged, new len: %ux\n", outs->dma_length);
560 			}
561 		}
562 
563 		if (segstart == s) {
564 			/* This is a new segment, fill entries */
565 			DBG("  - filling new segment.\n");
566 			outs->dma_address = dma_addr;
567 			outs->dma_length = slen;
568 		}
569 
570 		/* Calculate next page pointer for contiguous check */
571 		dma_next = dma_addr + slen;
572 
573 		DBG("  - dma next is: %lx\n", dma_next);
574 	}
575 
576 	/* Flush/invalidate TLB caches if necessary */
577 	if (tbl->it_ops->flush)
578 		tbl->it_ops->flush(tbl);
579 
580 	DBG("mapped %d elements:\n", outcount);
581 
582 	/* For the sake of ppc_iommu_unmap_sg, we clear out the length in the
583 	 * next entry of the sglist if we didn't fill the list completely
584 	 */
585 	if (outcount < incount) {
586 		outs = sg_next(outs);
587 		outs->dma_length = 0;
588 	}
589 
590 	/* Make sure updates are seen by hardware */
591 	mb();
592 
593 	return outcount;
594 
595  failure:
596 	for_each_sg(sglist, s, nelems, i) {
597 		if (s->dma_length != 0) {
598 			unsigned long vaddr, npages;
599 
600 			vaddr = s->dma_address & IOMMU_PAGE_MASK(tbl);
601 			npages = iommu_num_pages(s->dma_address, s->dma_length,
602 						 IOMMU_PAGE_SIZE(tbl));
603 			__iommu_free(tbl, vaddr, npages);
604 			s->dma_length = 0;
605 		}
606 		if (s == outs)
607 			break;
608 	}
609 	return -EIO;
610 }
611 
612 
613 void ppc_iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
614 			int nelems, enum dma_data_direction direction,
615 			unsigned long attrs)
616 {
617 	struct scatterlist *sg;
618 
619 	BUG_ON(direction == DMA_NONE);
620 
621 	if (!tbl)
622 		return;
623 
624 	sg = sglist;
625 	while (nelems--) {
626 		unsigned int npages;
627 		dma_addr_t dma_handle = sg->dma_address;
628 
629 		if (sg->dma_length == 0)
630 			break;
631 		npages = iommu_num_pages(dma_handle, sg->dma_length,
632 					 IOMMU_PAGE_SIZE(tbl));
633 		__iommu_free(tbl, dma_handle, npages);
634 		sg = sg_next(sg);
635 	}
636 
637 	/* Flush/invalidate TLBs if necessary. As for iommu_free(), we
638 	 * do not do an mb() here, the affected platforms do not need it
639 	 * when freeing.
640 	 */
641 	if (tbl->it_ops->flush)
642 		tbl->it_ops->flush(tbl);
643 }
644 
645 static void iommu_table_clear(struct iommu_table *tbl)
646 {
647 	/*
648 	 * In case of firmware assisted dump system goes through clean
649 	 * reboot process at the time of system crash. Hence it's safe to
650 	 * clear the TCE entries if firmware assisted dump is active.
651 	 */
652 	if (!is_kdump_kernel() || is_fadump_active()) {
653 		/* Clear the table in case firmware left allocations in it */
654 		tbl->it_ops->clear(tbl, tbl->it_offset, tbl->it_size);
655 		return;
656 	}
657 
658 #ifdef CONFIG_CRASH_DUMP
659 	if (tbl->it_ops->get) {
660 		unsigned long index, tceval, tcecount = 0;
661 
662 		/* Reserve the existing mappings left by the first kernel. */
663 		for (index = 0; index < tbl->it_size; index++) {
664 			tceval = tbl->it_ops->get(tbl, index + tbl->it_offset);
665 			/*
666 			 * Freed TCE entry contains 0x7fffffffffffffff on JS20
667 			 */
668 			if (tceval && (tceval != 0x7fffffffffffffffUL)) {
669 				__set_bit(index, tbl->it_map);
670 				tcecount++;
671 			}
672 		}
673 
674 		if ((tbl->it_size - tcecount) < KDUMP_MIN_TCE_ENTRIES) {
675 			printk(KERN_WARNING "TCE table is full; freeing ");
676 			printk(KERN_WARNING "%d entries for the kdump boot\n",
677 				KDUMP_MIN_TCE_ENTRIES);
678 			for (index = tbl->it_size - KDUMP_MIN_TCE_ENTRIES;
679 				index < tbl->it_size; index++)
680 				__clear_bit(index, tbl->it_map);
681 		}
682 	}
683 #endif
684 }
685 
686 static void iommu_table_reserve_pages(struct iommu_table *tbl,
687 		unsigned long res_start, unsigned long res_end)
688 {
689 	int i;
690 
691 	WARN_ON_ONCE(res_end < res_start);
692 	/*
693 	 * Reserve page 0 so it will not be used for any mappings.
694 	 * This avoids buggy drivers that consider page 0 to be invalid
695 	 * to crash the machine or even lose data.
696 	 */
697 	if (tbl->it_offset == 0)
698 		set_bit(0, tbl->it_map);
699 
700 	if (res_start < tbl->it_offset)
701 		res_start = tbl->it_offset;
702 
703 	if (res_end > (tbl->it_offset + tbl->it_size))
704 		res_end = tbl->it_offset + tbl->it_size;
705 
706 	/* Check if res_start..res_end is a valid range in the table */
707 	if (res_start >= res_end) {
708 		tbl->it_reserved_start = tbl->it_offset;
709 		tbl->it_reserved_end = tbl->it_offset;
710 		return;
711 	}
712 
713 	tbl->it_reserved_start = res_start;
714 	tbl->it_reserved_end = res_end;
715 
716 	for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
717 		set_bit(i - tbl->it_offset, tbl->it_map);
718 }
719 
720 /*
721  * Build a iommu_table structure.  This contains a bit map which
722  * is used to manage allocation of the tce space.
723  */
724 struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid,
725 		unsigned long res_start, unsigned long res_end)
726 {
727 	unsigned long sz;
728 	static int welcomed = 0;
729 	unsigned int i;
730 	struct iommu_pool *p;
731 
732 	BUG_ON(!tbl->it_ops);
733 
734 	/* number of bytes needed for the bitmap */
735 	sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long);
736 
737 	tbl->it_map = vzalloc_node(sz, nid);
738 	if (!tbl->it_map) {
739 		pr_err("%s: Can't allocate %ld bytes\n", __func__, sz);
740 		return NULL;
741 	}
742 
743 	iommu_table_reserve_pages(tbl, res_start, res_end);
744 
745 	/* We only split the IOMMU table if we have 1GB or more of space */
746 	if ((tbl->it_size << tbl->it_page_shift) >= (1UL * 1024 * 1024 * 1024))
747 		tbl->nr_pools = IOMMU_NR_POOLS;
748 	else
749 		tbl->nr_pools = 1;
750 
751 	/* We reserve the top 1/4 of the table for large allocations */
752 	tbl->poolsize = (tbl->it_size * 3 / 4) / tbl->nr_pools;
753 
754 	for (i = 0; i < tbl->nr_pools; i++) {
755 		p = &tbl->pools[i];
756 		spin_lock_init(&(p->lock));
757 		p->start = tbl->poolsize * i;
758 		p->hint = p->start;
759 		p->end = p->start + tbl->poolsize;
760 	}
761 
762 	p = &tbl->large_pool;
763 	spin_lock_init(&(p->lock));
764 	p->start = tbl->poolsize * i;
765 	p->hint = p->start;
766 	p->end = tbl->it_size;
767 
768 	iommu_table_clear(tbl);
769 
770 	if (!welcomed) {
771 		printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
772 		       novmerge ? "disabled" : "enabled");
773 		welcomed = 1;
774 	}
775 
776 	iommu_debugfs_add(tbl);
777 
778 	return tbl;
779 }
780 
781 bool iommu_table_in_use(struct iommu_table *tbl)
782 {
783 	unsigned long start = 0, end;
784 
785 	/* ignore reserved bit0 */
786 	if (tbl->it_offset == 0)
787 		start = 1;
788 
789 	/* Simple case with no reserved MMIO32 region */
790 	if (!tbl->it_reserved_start && !tbl->it_reserved_end)
791 		return find_next_bit(tbl->it_map, tbl->it_size, start) != tbl->it_size;
792 
793 	end = tbl->it_reserved_start - tbl->it_offset;
794 	if (find_next_bit(tbl->it_map, end, start) != end)
795 		return true;
796 
797 	start = tbl->it_reserved_end - tbl->it_offset;
798 	end = tbl->it_size;
799 	return find_next_bit(tbl->it_map, end, start) != end;
800 }
801 
802 static void iommu_table_free(struct kref *kref)
803 {
804 	struct iommu_table *tbl;
805 
806 	tbl = container_of(kref, struct iommu_table, it_kref);
807 
808 	if (tbl->it_ops->free)
809 		tbl->it_ops->free(tbl);
810 
811 	if (!tbl->it_map) {
812 		kfree(tbl);
813 		return;
814 	}
815 
816 	iommu_debugfs_del(tbl);
817 
818 	/* verify that table contains no entries */
819 	if (iommu_table_in_use(tbl))
820 		pr_warn("%s: Unexpected TCEs\n", __func__);
821 
822 	/* free bitmap */
823 	vfree(tbl->it_map);
824 
825 	/* free table */
826 	kfree(tbl);
827 }
828 
829 struct iommu_table *iommu_tce_table_get(struct iommu_table *tbl)
830 {
831 	if (kref_get_unless_zero(&tbl->it_kref))
832 		return tbl;
833 
834 	return NULL;
835 }
836 EXPORT_SYMBOL_GPL(iommu_tce_table_get);
837 
838 int iommu_tce_table_put(struct iommu_table *tbl)
839 {
840 	if (WARN_ON(!tbl))
841 		return 0;
842 
843 	return kref_put(&tbl->it_kref, iommu_table_free);
844 }
845 EXPORT_SYMBOL_GPL(iommu_tce_table_put);
846 
847 /* Creates TCEs for a user provided buffer.  The user buffer must be
848  * contiguous real kernel storage (not vmalloc).  The address passed here
849  * comprises a page address and offset into that page. The dma_addr_t
850  * returned will point to the same byte within the page as was passed in.
851  */
852 dma_addr_t iommu_map_page(struct device *dev, struct iommu_table *tbl,
853 			  struct page *page, unsigned long offset, size_t size,
854 			  unsigned long mask, enum dma_data_direction direction,
855 			  unsigned long attrs)
856 {
857 	dma_addr_t dma_handle = DMA_MAPPING_ERROR;
858 	void *vaddr;
859 	unsigned long uaddr;
860 	unsigned int npages, align;
861 
862 	BUG_ON(direction == DMA_NONE);
863 
864 	vaddr = page_address(page) + offset;
865 	uaddr = (unsigned long)vaddr;
866 
867 	if (tbl) {
868 		npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl));
869 		align = 0;
870 		if (tbl->it_page_shift < PAGE_SHIFT && size >= PAGE_SIZE &&
871 		    ((unsigned long)vaddr & ~PAGE_MASK) == 0)
872 			align = PAGE_SHIFT - tbl->it_page_shift;
873 
874 		dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction,
875 					 mask >> tbl->it_page_shift, align,
876 					 attrs);
877 		if (dma_handle == DMA_MAPPING_ERROR) {
878 			if (!(attrs & DMA_ATTR_NO_WARN) &&
879 			    printk_ratelimit())  {
880 				dev_info(dev, "iommu_alloc failed, tbl %p "
881 					 "vaddr %p npages %d\n", tbl, vaddr,
882 					 npages);
883 			}
884 		} else
885 			dma_handle |= (uaddr & ~IOMMU_PAGE_MASK(tbl));
886 	}
887 
888 	return dma_handle;
889 }
890 
891 void iommu_unmap_page(struct iommu_table *tbl, dma_addr_t dma_handle,
892 		      size_t size, enum dma_data_direction direction,
893 		      unsigned long attrs)
894 {
895 	unsigned int npages;
896 
897 	BUG_ON(direction == DMA_NONE);
898 
899 	if (tbl) {
900 		npages = iommu_num_pages(dma_handle, size,
901 					 IOMMU_PAGE_SIZE(tbl));
902 		iommu_free(tbl, dma_handle, npages);
903 	}
904 }
905 
906 /* Allocates a contiguous real buffer and creates mappings over it.
907  * Returns the virtual address of the buffer and sets dma_handle
908  * to the dma address (mapping) of the first page.
909  */
910 void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
911 			   size_t size,	dma_addr_t *dma_handle,
912 			   unsigned long mask, gfp_t flag, int node)
913 {
914 	void *ret = NULL;
915 	dma_addr_t mapping;
916 	unsigned int order;
917 	unsigned int nio_pages, io_order;
918 	struct page *page;
919 	int tcesize = (1 << tbl->it_page_shift);
920 
921 	size = PAGE_ALIGN(size);
922 	order = get_order(size);
923 
924  	/*
925 	 * Client asked for way too much space.  This is checked later
926 	 * anyway.  It is easier to debug here for the drivers than in
927 	 * the tce tables.
928 	 */
929 	if (order >= IOMAP_MAX_ORDER) {
930 		dev_info(dev, "iommu_alloc_consistent size too large: 0x%lx\n",
931 			 size);
932 		return NULL;
933 	}
934 
935 	if (!tbl)
936 		return NULL;
937 
938 	/* Alloc enough pages (and possibly more) */
939 	page = alloc_pages_node(node, flag, order);
940 	if (!page)
941 		return NULL;
942 	ret = page_address(page);
943 	memset(ret, 0, size);
944 
945 	/* Set up tces to cover the allocated range */
946 	nio_pages = IOMMU_PAGE_ALIGN(size, tbl) >> tbl->it_page_shift;
947 
948 	io_order = get_iommu_order(size, tbl);
949 	mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
950 			      mask >> tbl->it_page_shift, io_order, 0);
951 	if (mapping == DMA_MAPPING_ERROR) {
952 		free_pages((unsigned long)ret, order);
953 		return NULL;
954 	}
955 
956 	*dma_handle = mapping | ((u64)ret & (tcesize - 1));
957 	return ret;
958 }
959 
960 void iommu_free_coherent(struct iommu_table *tbl, size_t size,
961 			 void *vaddr, dma_addr_t dma_handle)
962 {
963 	if (tbl) {
964 		unsigned int nio_pages;
965 
966 		size = PAGE_ALIGN(size);
967 		nio_pages = IOMMU_PAGE_ALIGN(size, tbl) >> tbl->it_page_shift;
968 		iommu_free(tbl, dma_handle, nio_pages);
969 		size = PAGE_ALIGN(size);
970 		free_pages((unsigned long)vaddr, get_order(size));
971 	}
972 }
973 
974 unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir)
975 {
976 	switch (dir) {
977 	case DMA_BIDIRECTIONAL:
978 		return TCE_PCI_READ | TCE_PCI_WRITE;
979 	case DMA_FROM_DEVICE:
980 		return TCE_PCI_WRITE;
981 	case DMA_TO_DEVICE:
982 		return TCE_PCI_READ;
983 	default:
984 		return 0;
985 	}
986 }
987 EXPORT_SYMBOL_GPL(iommu_direction_to_tce_perm);
988 
989 #ifdef CONFIG_IOMMU_API
990 /*
991  * SPAPR TCE API
992  */
993 static void group_release(void *iommu_data)
994 {
995 	struct iommu_table_group *table_group = iommu_data;
996 
997 	table_group->group = NULL;
998 }
999 
1000 void iommu_register_group(struct iommu_table_group *table_group,
1001 		int pci_domain_number, unsigned long pe_num)
1002 {
1003 	struct iommu_group *grp;
1004 	char *name;
1005 
1006 	grp = iommu_group_alloc();
1007 	if (IS_ERR(grp)) {
1008 		pr_warn("powerpc iommu api: cannot create new group, err=%ld\n",
1009 				PTR_ERR(grp));
1010 		return;
1011 	}
1012 	table_group->group = grp;
1013 	iommu_group_set_iommudata(grp, table_group, group_release);
1014 	name = kasprintf(GFP_KERNEL, "domain%d-pe%lx",
1015 			pci_domain_number, pe_num);
1016 	if (!name)
1017 		return;
1018 	iommu_group_set_name(grp, name);
1019 	kfree(name);
1020 }
1021 
1022 enum dma_data_direction iommu_tce_direction(unsigned long tce)
1023 {
1024 	if ((tce & TCE_PCI_READ) && (tce & TCE_PCI_WRITE))
1025 		return DMA_BIDIRECTIONAL;
1026 	else if (tce & TCE_PCI_READ)
1027 		return DMA_TO_DEVICE;
1028 	else if (tce & TCE_PCI_WRITE)
1029 		return DMA_FROM_DEVICE;
1030 	else
1031 		return DMA_NONE;
1032 }
1033 EXPORT_SYMBOL_GPL(iommu_tce_direction);
1034 
1035 void iommu_flush_tce(struct iommu_table *tbl)
1036 {
1037 	/* Flush/invalidate TLB caches if necessary */
1038 	if (tbl->it_ops->flush)
1039 		tbl->it_ops->flush(tbl);
1040 
1041 	/* Make sure updates are seen by hardware */
1042 	mb();
1043 }
1044 EXPORT_SYMBOL_GPL(iommu_flush_tce);
1045 
1046 int iommu_tce_check_ioba(unsigned long page_shift,
1047 		unsigned long offset, unsigned long size,
1048 		unsigned long ioba, unsigned long npages)
1049 {
1050 	unsigned long mask = (1UL << page_shift) - 1;
1051 
1052 	if (ioba & mask)
1053 		return -EINVAL;
1054 
1055 	ioba >>= page_shift;
1056 	if (ioba < offset)
1057 		return -EINVAL;
1058 
1059 	if ((ioba + 1) > (offset + size))
1060 		return -EINVAL;
1061 
1062 	return 0;
1063 }
1064 EXPORT_SYMBOL_GPL(iommu_tce_check_ioba);
1065 
1066 int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa)
1067 {
1068 	unsigned long mask = (1UL << page_shift) - 1;
1069 
1070 	if (gpa & mask)
1071 		return -EINVAL;
1072 
1073 	return 0;
1074 }
1075 EXPORT_SYMBOL_GPL(iommu_tce_check_gpa);
1076 
1077 extern long iommu_tce_xchg_no_kill(struct mm_struct *mm,
1078 		struct iommu_table *tbl,
1079 		unsigned long entry, unsigned long *hpa,
1080 		enum dma_data_direction *direction)
1081 {
1082 	long ret;
1083 	unsigned long size = 0;
1084 
1085 	ret = tbl->it_ops->xchg_no_kill(tbl, entry, hpa, direction);
1086 	if (!ret && ((*direction == DMA_FROM_DEVICE) ||
1087 			(*direction == DMA_BIDIRECTIONAL)) &&
1088 			!mm_iommu_is_devmem(mm, *hpa, tbl->it_page_shift,
1089 					&size))
1090 		SetPageDirty(pfn_to_page(*hpa >> PAGE_SHIFT));
1091 
1092 	return ret;
1093 }
1094 EXPORT_SYMBOL_GPL(iommu_tce_xchg_no_kill);
1095 
1096 void iommu_tce_kill(struct iommu_table *tbl,
1097 		unsigned long entry, unsigned long pages)
1098 {
1099 	if (tbl->it_ops->tce_kill)
1100 		tbl->it_ops->tce_kill(tbl, entry, pages);
1101 }
1102 EXPORT_SYMBOL_GPL(iommu_tce_kill);
1103 
1104 #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
1105 static int iommu_take_ownership(struct iommu_table *tbl)
1106 {
1107 	unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
1108 	int ret = 0;
1109 
1110 	/*
1111 	 * VFIO does not control TCE entries allocation and the guest
1112 	 * can write new TCEs on top of existing ones so iommu_tce_build()
1113 	 * must be able to release old pages. This functionality
1114 	 * requires exchange() callback defined so if it is not
1115 	 * implemented, we disallow taking ownership over the table.
1116 	 */
1117 	if (!tbl->it_ops->xchg_no_kill)
1118 		return -EINVAL;
1119 
1120 	spin_lock_irqsave(&tbl->large_pool.lock, flags);
1121 	for (i = 0; i < tbl->nr_pools; i++)
1122 		spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock);
1123 
1124 	if (iommu_table_in_use(tbl)) {
1125 		pr_err("iommu_tce: it_map is not empty");
1126 		ret = -EBUSY;
1127 	} else {
1128 		memset(tbl->it_map, 0xff, sz);
1129 	}
1130 
1131 	for (i = 0; i < tbl->nr_pools; i++)
1132 		spin_unlock(&tbl->pools[i].lock);
1133 	spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
1134 
1135 	return ret;
1136 }
1137 
1138 static void iommu_release_ownership(struct iommu_table *tbl)
1139 {
1140 	unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
1141 
1142 	spin_lock_irqsave(&tbl->large_pool.lock, flags);
1143 	for (i = 0; i < tbl->nr_pools; i++)
1144 		spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock);
1145 
1146 	memset(tbl->it_map, 0, sz);
1147 
1148 	iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
1149 			tbl->it_reserved_end);
1150 
1151 	for (i = 0; i < tbl->nr_pools; i++)
1152 		spin_unlock(&tbl->pools[i].lock);
1153 	spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
1154 }
1155 #endif
1156 
1157 int iommu_add_device(struct iommu_table_group *table_group, struct device *dev)
1158 {
1159 	/*
1160 	 * The sysfs entries should be populated before
1161 	 * binding IOMMU group. If sysfs entries isn't
1162 	 * ready, we simply bail.
1163 	 */
1164 	if (!device_is_registered(dev))
1165 		return -ENOENT;
1166 
1167 	if (device_iommu_mapped(dev)) {
1168 		pr_debug("%s: Skipping device %s with iommu group %d\n",
1169 			 __func__, dev_name(dev),
1170 			 iommu_group_id(dev->iommu_group));
1171 		return -EBUSY;
1172 	}
1173 
1174 	pr_debug("%s: Adding %s to iommu group %d\n",
1175 		 __func__, dev_name(dev),  iommu_group_id(table_group->group));
1176 	/*
1177 	 * This is still not adding devices via the IOMMU bus notifier because
1178 	 * of pcibios_init() from arch/powerpc/kernel/pci_64.c which calls
1179 	 * pcibios_scan_phb() first (and this guy adds devices and triggers
1180 	 * the notifier) and only then it calls pci_bus_add_devices() which
1181 	 * configures DMA for buses which also creates PEs and IOMMU groups.
1182 	 */
1183 	return iommu_probe_device(dev);
1184 }
1185 EXPORT_SYMBOL_GPL(iommu_add_device);
1186 
1187 #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
1188 /*
1189  * A simple iommu_table_group_ops which only allows reusing the existing
1190  * iommu_table. This handles VFIO for POWER7 or the nested KVM.
1191  * The ops does not allow creating windows and only allows reusing the existing
1192  * one if it matches table_group->tce32_start/tce32_size/page_shift.
1193  */
1194 static unsigned long spapr_tce_get_table_size(__u32 page_shift,
1195 					      __u64 window_size, __u32 levels)
1196 {
1197 	unsigned long size;
1198 
1199 	if (levels > 1)
1200 		return ~0U;
1201 	size = window_size >> (page_shift - 3);
1202 	return size;
1203 }
1204 
1205 static long spapr_tce_create_table(struct iommu_table_group *table_group, int num,
1206 				   __u32 page_shift, __u64 window_size, __u32 levels,
1207 				   struct iommu_table **ptbl)
1208 {
1209 	struct iommu_table *tbl = table_group->tables[0];
1210 
1211 	if (num > 0)
1212 		return -EPERM;
1213 
1214 	if (tbl->it_page_shift != page_shift ||
1215 	    tbl->it_size != (window_size >> page_shift) ||
1216 	    tbl->it_indirect_levels != levels - 1)
1217 		return -EINVAL;
1218 
1219 	*ptbl = iommu_tce_table_get(tbl);
1220 	return 0;
1221 }
1222 
1223 static long spapr_tce_set_window(struct iommu_table_group *table_group,
1224 				 int num, struct iommu_table *tbl)
1225 {
1226 	return tbl == table_group->tables[num] ? 0 : -EPERM;
1227 }
1228 
1229 static long spapr_tce_unset_window(struct iommu_table_group *table_group, int num)
1230 {
1231 	return 0;
1232 }
1233 
1234 static long spapr_tce_take_ownership(struct iommu_table_group *table_group)
1235 {
1236 	int i, j, rc = 0;
1237 
1238 	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1239 		struct iommu_table *tbl = table_group->tables[i];
1240 
1241 		if (!tbl || !tbl->it_map)
1242 			continue;
1243 
1244 		rc = iommu_take_ownership(tbl);
1245 		if (!rc)
1246 			continue;
1247 
1248 		for (j = 0; j < i; ++j)
1249 			iommu_release_ownership(table_group->tables[j]);
1250 		return rc;
1251 	}
1252 	return 0;
1253 }
1254 
1255 static void spapr_tce_release_ownership(struct iommu_table_group *table_group)
1256 {
1257 	int i;
1258 
1259 	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1260 		struct iommu_table *tbl = table_group->tables[i];
1261 
1262 		if (!tbl)
1263 			continue;
1264 
1265 		iommu_table_clear(tbl);
1266 		if (tbl->it_map)
1267 			iommu_release_ownership(tbl);
1268 	}
1269 }
1270 
1271 struct iommu_table_group_ops spapr_tce_table_group_ops = {
1272 	.get_table_size = spapr_tce_get_table_size,
1273 	.create_table = spapr_tce_create_table,
1274 	.set_window = spapr_tce_set_window,
1275 	.unset_window = spapr_tce_unset_window,
1276 	.take_ownership = spapr_tce_take_ownership,
1277 	.release_ownership = spapr_tce_release_ownership,
1278 };
1279 
1280 /*
1281  * A simple iommu_ops to allow less cruft in generic VFIO code.
1282  */
1283 static int spapr_tce_blocking_iommu_attach_dev(struct iommu_domain *dom,
1284 					       struct device *dev)
1285 {
1286 	struct iommu_group *grp = iommu_group_get(dev);
1287 	struct iommu_table_group *table_group;
1288 	int ret = -EINVAL;
1289 
1290 	if (!grp)
1291 		return -ENODEV;
1292 
1293 	table_group = iommu_group_get_iommudata(grp);
1294 	ret = table_group->ops->take_ownership(table_group);
1295 	iommu_group_put(grp);
1296 
1297 	return ret;
1298 }
1299 
1300 static void spapr_tce_blocking_iommu_set_platform_dma(struct device *dev)
1301 {
1302 	struct iommu_group *grp = iommu_group_get(dev);
1303 	struct iommu_table_group *table_group;
1304 
1305 	table_group = iommu_group_get_iommudata(grp);
1306 	table_group->ops->release_ownership(table_group);
1307 }
1308 
1309 static const struct iommu_domain_ops spapr_tce_blocking_domain_ops = {
1310 	.attach_dev = spapr_tce_blocking_iommu_attach_dev,
1311 };
1312 
1313 static bool spapr_tce_iommu_capable(struct device *dev, enum iommu_cap cap)
1314 {
1315 	switch (cap) {
1316 	case IOMMU_CAP_CACHE_COHERENCY:
1317 		return true;
1318 	default:
1319 		break;
1320 	}
1321 
1322 	return false;
1323 }
1324 
1325 static struct iommu_domain *spapr_tce_iommu_domain_alloc(unsigned int type)
1326 {
1327 	struct iommu_domain *dom;
1328 
1329 	if (type != IOMMU_DOMAIN_BLOCKED)
1330 		return NULL;
1331 
1332 	dom = kzalloc(sizeof(*dom), GFP_KERNEL);
1333 	if (!dom)
1334 		return NULL;
1335 
1336 	dom->ops = &spapr_tce_blocking_domain_ops;
1337 
1338 	return dom;
1339 }
1340 
1341 static struct iommu_device *spapr_tce_iommu_probe_device(struct device *dev)
1342 {
1343 	struct pci_dev *pdev;
1344 	struct pci_controller *hose;
1345 
1346 	if (!dev_is_pci(dev))
1347 		return ERR_PTR(-EPERM);
1348 
1349 	pdev = to_pci_dev(dev);
1350 	hose = pdev->bus->sysdata;
1351 
1352 	return &hose->iommu;
1353 }
1354 
1355 static void spapr_tce_iommu_release_device(struct device *dev)
1356 {
1357 }
1358 
1359 static struct iommu_group *spapr_tce_iommu_device_group(struct device *dev)
1360 {
1361 	struct pci_controller *hose;
1362 	struct pci_dev *pdev;
1363 
1364 	pdev = to_pci_dev(dev);
1365 	hose = pdev->bus->sysdata;
1366 
1367 	if (!hose->controller_ops.device_group)
1368 		return ERR_PTR(-ENOENT);
1369 
1370 	return hose->controller_ops.device_group(hose, pdev);
1371 }
1372 
1373 static const struct iommu_ops spapr_tce_iommu_ops = {
1374 	.capable = spapr_tce_iommu_capable,
1375 	.domain_alloc = spapr_tce_iommu_domain_alloc,
1376 	.probe_device = spapr_tce_iommu_probe_device,
1377 	.release_device = spapr_tce_iommu_release_device,
1378 	.device_group = spapr_tce_iommu_device_group,
1379 	.set_platform_dma_ops = spapr_tce_blocking_iommu_set_platform_dma,
1380 };
1381 
1382 static struct attribute *spapr_tce_iommu_attrs[] = {
1383 	NULL,
1384 };
1385 
1386 static struct attribute_group spapr_tce_iommu_group = {
1387 	.name = "spapr-tce-iommu",
1388 	.attrs = spapr_tce_iommu_attrs,
1389 };
1390 
1391 static const struct attribute_group *spapr_tce_iommu_groups[] = {
1392 	&spapr_tce_iommu_group,
1393 	NULL,
1394 };
1395 
1396 /*
1397  * This registers IOMMU devices of PHBs. This needs to happen
1398  * after core_initcall(iommu_init) + postcore_initcall(pci_driver_init) and
1399  * before subsys_initcall(iommu_subsys_init).
1400  */
1401 static int __init spapr_tce_setup_phb_iommus_initcall(void)
1402 {
1403 	struct pci_controller *hose;
1404 
1405 	list_for_each_entry(hose, &hose_list, list_node) {
1406 		iommu_device_sysfs_add(&hose->iommu, hose->parent,
1407 				       spapr_tce_iommu_groups, "iommu-phb%04x",
1408 				       hose->global_number);
1409 		iommu_device_register(&hose->iommu, &spapr_tce_iommu_ops,
1410 				      hose->parent);
1411 	}
1412 	return 0;
1413 }
1414 postcore_initcall_sync(spapr_tce_setup_phb_iommus_initcall);
1415 #endif
1416 
1417 #endif /* CONFIG_IOMMU_API */
1418