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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 <asm/io.h>
29#include <asm/prom.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
39#define DBG(...)
40
41static int novmerge;
42
43static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);
44
45static int __init setup_iommu(char *str)
46{
47 if (!strcmp(str, "novmerge"))
48 novmerge = 1;
49 else if (!strcmp(str, "vmerge"))
50 novmerge = 0;
51 return 1;
52}
53
54__setup("iommu=", setup_iommu);
55
56static DEFINE_PER_CPU(unsigned int, iommu_pool_hash);
57
58/*
59 * We precalculate the hash to avoid doing it on every allocation.
60 *
61 * The hash is important to spread CPUs across all the pools. For example,
62 * on a POWER7 with 4 way SMT we want interrupts on the primary threads and
63 * with 4 pools all primary threads would map to the same pool.
64 */
65static int __init setup_iommu_pool_hash(void)
66{
67 unsigned int i;
68
69 for_each_possible_cpu(i)
70 per_cpu(iommu_pool_hash, i) = hash_32(i, IOMMU_POOL_HASHBITS);
71
72 return 0;
73}
74subsys_initcall(setup_iommu_pool_hash);
75
76#ifdef CONFIG_FAIL_IOMMU
77
78static DECLARE_FAULT_ATTR(fail_iommu);
79
80static int __init setup_fail_iommu(char *str)
81{
82 return setup_fault_attr(&fail_iommu, str);
83}
84__setup("fail_iommu=", setup_fail_iommu);
85
86static bool should_fail_iommu(struct device *dev)
87{
88 return dev->archdata.fail_iommu && should_fail(&fail_iommu, 1);
89}
90
91static int __init fail_iommu_debugfs(void)
92{
93 struct dentry *dir = fault_create_debugfs_attr("fail_iommu",
94 NULL, &fail_iommu);
95
96 return PTR_ERR_OR_ZERO(dir);
97}
98late_initcall(fail_iommu_debugfs);
99
100static ssize_t fail_iommu_show(struct device *dev,
101 struct device_attribute *attr, char *buf)
102{
103 return sprintf(buf, "%d\n", dev->archdata.fail_iommu);
104}
105
106static ssize_t fail_iommu_store(struct device *dev,
107 struct device_attribute *attr, const char *buf,
108 size_t count)
109{
110 int i;
111
112 if (count > 0 && sscanf(buf, "%d", &i) > 0)
113 dev->archdata.fail_iommu = (i == 0) ? 0 : 1;
114
115 return count;
116}
117
118static DEVICE_ATTR_RW(fail_iommu);
119
120static int fail_iommu_bus_notify(struct notifier_block *nb,
121 unsigned long action, void *data)
122{
123 struct device *dev = data;
124
125 if (action == BUS_NOTIFY_ADD_DEVICE) {
126 if (device_create_file(dev, &dev_attr_fail_iommu))
127 pr_warn("Unable to create IOMMU fault injection sysfs "
128 "entries\n");
129 } else if (action == BUS_NOTIFY_DEL_DEVICE) {
130 device_remove_file(dev, &dev_attr_fail_iommu);
131 }
132
133 return 0;
134}
135
136static struct notifier_block fail_iommu_bus_notifier = {
137 .notifier_call = fail_iommu_bus_notify
138};
139
140static int __init fail_iommu_setup(void)
141{
142#ifdef CONFIG_PCI
143 bus_register_notifier(&pci_bus_type, &fail_iommu_bus_notifier);
144#endif
145#ifdef CONFIG_IBMVIO
146 bus_register_notifier(&vio_bus_type, &fail_iommu_bus_notifier);
147#endif
148
149 return 0;
150}
151/*
152 * Must execute after PCI and VIO subsystem have initialised but before
153 * devices are probed.
154 */
155arch_initcall(fail_iommu_setup);
156#else
157static inline bool should_fail_iommu(struct device *dev)
158{
159 return false;
160}
161#endif
162
163static unsigned long iommu_range_alloc(struct device *dev,
164 struct iommu_table *tbl,
165 unsigned long npages,
166 unsigned long *handle,
167 unsigned long mask,
168 unsigned int align_order)
169{
170 unsigned long n, end, start;
171 unsigned long limit;
172 int largealloc = npages > 15;
173 int pass = 0;
174 unsigned long align_mask;
175 unsigned long boundary_size;
176 unsigned long flags;
177 unsigned int pool_nr;
178 struct iommu_pool *pool;
179
180 align_mask = (1ull << align_order) - 1;
181
182 /* This allocator was derived from x86_64's bit string search */
183
184 /* Sanity check */
185 if (unlikely(npages == 0)) {
186 if (printk_ratelimit())
187 WARN_ON(1);
188 return DMA_MAPPING_ERROR;
189 }
190
191 if (should_fail_iommu(dev))
192 return DMA_MAPPING_ERROR;
193
194 /*
195 * We don't need to disable preemption here because any CPU can
196 * safely use any IOMMU pool.
197 */
198 pool_nr = raw_cpu_read(iommu_pool_hash) & (tbl->nr_pools - 1);
199
200 if (largealloc)
201 pool = &(tbl->large_pool);
202 else
203 pool = &(tbl->pools[pool_nr]);
204
205 spin_lock_irqsave(&(pool->lock), flags);
206
207again:
208 if ((pass == 0) && handle && *handle &&
209 (*handle >= pool->start) && (*handle < pool->end))
210 start = *handle;
211 else
212 start = pool->hint;
213
214 limit = pool->end;
215
216 /* The case below can happen if we have a small segment appended
217 * to a large, or when the previous alloc was at the very end of
218 * the available space. If so, go back to the initial start.
219 */
220 if (start >= limit)
221 start = pool->start;
222
223 if (limit + tbl->it_offset > mask) {
224 limit = mask - tbl->it_offset + 1;
225 /* If we're constrained on address range, first try
226 * at the masked hint to avoid O(n) search complexity,
227 * but on second pass, start at 0 in pool 0.
228 */
229 if ((start & mask) >= limit || pass > 0) {
230 spin_unlock(&(pool->lock));
231 pool = &(tbl->pools[0]);
232 spin_lock(&(pool->lock));
233 start = pool->start;
234 } else {
235 start &= mask;
236 }
237 }
238
239 if (dev)
240 boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
241 1 << tbl->it_page_shift);
242 else
243 boundary_size = ALIGN(1UL << 32, 1 << tbl->it_page_shift);
244 /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */
245
246 n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset,
247 boundary_size >> tbl->it_page_shift, align_mask);
248 if (n == -1) {
249 if (likely(pass == 0)) {
250 /* First try the pool from the start */
251 pool->hint = pool->start;
252 pass++;
253 goto again;
254
255 } else if (pass <= tbl->nr_pools) {
256 /* Now try scanning all the other pools */
257 spin_unlock(&(pool->lock));
258 pool_nr = (pool_nr + 1) & (tbl->nr_pools - 1);
259 pool = &tbl->pools[pool_nr];
260 spin_lock(&(pool->lock));
261 pool->hint = pool->start;
262 pass++;
263 goto again;
264
265 } else {
266 /* Give up */
267 spin_unlock_irqrestore(&(pool->lock), flags);
268 return DMA_MAPPING_ERROR;
269 }
270 }
271
272 end = n + npages;
273
274 /* Bump the hint to a new block for small allocs. */
275 if (largealloc) {
276 /* Don't bump to new block to avoid fragmentation */
277 pool->hint = end;
278 } else {
279 /* Overflow will be taken care of at the next allocation */
280 pool->hint = (end + tbl->it_blocksize - 1) &
281 ~(tbl->it_blocksize - 1);
282 }
283
284 /* Update handle for SG allocations */
285 if (handle)
286 *handle = end;
287
288 spin_unlock_irqrestore(&(pool->lock), flags);
289
290 return n;
291}
292
293static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
294 void *page, unsigned int npages,
295 enum dma_data_direction direction,
296 unsigned long mask, unsigned int align_order,
297 unsigned long attrs)
298{
299 unsigned long entry;
300 dma_addr_t ret = DMA_MAPPING_ERROR;
301 int build_fail;
302
303 entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order);
304
305 if (unlikely(entry == DMA_MAPPING_ERROR))
306 return DMA_MAPPING_ERROR;
307
308 entry += tbl->it_offset; /* Offset into real TCE table */
309 ret = entry << tbl->it_page_shift; /* Set the return dma address */
310
311 /* Put the TCEs in the HW table */
312 build_fail = tbl->it_ops->set(tbl, entry, npages,
313 (unsigned long)page &
314 IOMMU_PAGE_MASK(tbl), direction, attrs);
315
316 /* tbl->it_ops->set() only returns non-zero for transient errors.
317 * Clean up the table bitmap in this case and return
318 * DMA_MAPPING_ERROR. For all other errors the functionality is
319 * not altered.
320 */
321 if (unlikely(build_fail)) {
322 __iommu_free(tbl, ret, npages);
323 return DMA_MAPPING_ERROR;
324 }
325
326 /* Flush/invalidate TLB caches if necessary */
327 if (tbl->it_ops->flush)
328 tbl->it_ops->flush(tbl);
329
330 /* Make sure updates are seen by hardware */
331 mb();
332
333 return ret;
334}
335
336static bool iommu_free_check(struct iommu_table *tbl, dma_addr_t dma_addr,
337 unsigned int npages)
338{
339 unsigned long entry, free_entry;
340
341 entry = dma_addr >> tbl->it_page_shift;
342 free_entry = entry - tbl->it_offset;
343
344 if (((free_entry + npages) > tbl->it_size) ||
345 (entry < tbl->it_offset)) {
346 if (printk_ratelimit()) {
347 printk(KERN_INFO "iommu_free: invalid entry\n");
348 printk(KERN_INFO "\tentry = 0x%lx\n", entry);
349 printk(KERN_INFO "\tdma_addr = 0x%llx\n", (u64)dma_addr);
350 printk(KERN_INFO "\tTable = 0x%llx\n", (u64)tbl);
351 printk(KERN_INFO "\tbus# = 0x%llx\n", (u64)tbl->it_busno);
352 printk(KERN_INFO "\tsize = 0x%llx\n", (u64)tbl->it_size);
353 printk(KERN_INFO "\tstartOff = 0x%llx\n", (u64)tbl->it_offset);
354 printk(KERN_INFO "\tindex = 0x%llx\n", (u64)tbl->it_index);
355 WARN_ON(1);
356 }
357
358 return false;
359 }
360
361 return true;
362}
363
364static struct iommu_pool *get_pool(struct iommu_table *tbl,
365 unsigned long entry)
366{
367 struct iommu_pool *p;
368 unsigned long largepool_start = tbl->large_pool.start;
369
370 /* The large pool is the last pool at the top of the table */
371 if (entry >= largepool_start) {
372 p = &tbl->large_pool;
373 } else {
374 unsigned int pool_nr = entry / tbl->poolsize;
375
376 BUG_ON(pool_nr > tbl->nr_pools);
377 p = &tbl->pools[pool_nr];
378 }
379
380 return p;
381}
382
383static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
384 unsigned int npages)
385{
386 unsigned long entry, free_entry;
387 unsigned long flags;
388 struct iommu_pool *pool;
389
390 entry = dma_addr >> tbl->it_page_shift;
391 free_entry = entry - tbl->it_offset;
392
393 pool = get_pool(tbl, free_entry);
394
395 if (!iommu_free_check(tbl, dma_addr, npages))
396 return;
397
398 tbl->it_ops->clear(tbl, entry, npages);
399
400 spin_lock_irqsave(&(pool->lock), flags);
401 bitmap_clear(tbl->it_map, free_entry, npages);
402 spin_unlock_irqrestore(&(pool->lock), flags);
403}
404
405static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
406 unsigned int npages)
407{
408 __iommu_free(tbl, dma_addr, npages);
409
410 /* Make sure TLB cache is flushed if the HW needs it. We do
411 * not do an mb() here on purpose, it is not needed on any of
412 * the current platforms.
413 */
414 if (tbl->it_ops->flush)
415 tbl->it_ops->flush(tbl);
416}
417
418int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl,
419 struct scatterlist *sglist, int nelems,
420 unsigned long mask, enum dma_data_direction direction,
421 unsigned long attrs)
422{
423 dma_addr_t dma_next = 0, dma_addr;
424 struct scatterlist *s, *outs, *segstart;
425 int outcount, incount, i, build_fail = 0;
426 unsigned int align;
427 unsigned long handle;
428 unsigned int max_seg_size;
429
430 BUG_ON(direction == DMA_NONE);
431
432 if ((nelems == 0) || !tbl)
433 return 0;
434
435 outs = s = segstart = &sglist[0];
436 outcount = 1;
437 incount = nelems;
438 handle = 0;
439
440 /* Init first segment length for backout at failure */
441 outs->dma_length = 0;
442
443 DBG("sg mapping %d elements:\n", nelems);
444
445 max_seg_size = dma_get_max_seg_size(dev);
446 for_each_sg(sglist, s, nelems, i) {
447 unsigned long vaddr, npages, entry, slen;
448
449 slen = s->length;
450 /* Sanity check */
451 if (slen == 0) {
452 dma_next = 0;
453 continue;
454 }
455 /* Allocate iommu entries for that segment */
456 vaddr = (unsigned long) sg_virt(s);
457 npages = iommu_num_pages(vaddr, slen, IOMMU_PAGE_SIZE(tbl));
458 align = 0;
459 if (tbl->it_page_shift < PAGE_SHIFT && slen >= PAGE_SIZE &&
460 (vaddr & ~PAGE_MASK) == 0)
461 align = PAGE_SHIFT - tbl->it_page_shift;
462 entry = iommu_range_alloc(dev, tbl, npages, &handle,
463 mask >> tbl->it_page_shift, align);
464
465 DBG(" - vaddr: %lx, size: %lx\n", vaddr, slen);
466
467 /* Handle failure */
468 if (unlikely(entry == DMA_MAPPING_ERROR)) {
469 if (!(attrs & DMA_ATTR_NO_WARN) &&
470 printk_ratelimit())
471 dev_info(dev, "iommu_alloc failed, tbl %p "
472 "vaddr %lx npages %lu\n", tbl, vaddr,
473 npages);
474 goto failure;
475 }
476
477 /* Convert entry to a dma_addr_t */
478 entry += tbl->it_offset;
479 dma_addr = entry << tbl->it_page_shift;
480 dma_addr |= (s->offset & ~IOMMU_PAGE_MASK(tbl));
481
482 DBG(" - %lu pages, entry: %lx, dma_addr: %lx\n",
483 npages, entry, dma_addr);
484
485 /* Insert into HW table */
486 build_fail = tbl->it_ops->set(tbl, entry, npages,
487 vaddr & IOMMU_PAGE_MASK(tbl),
488 direction, attrs);
489 if(unlikely(build_fail))
490 goto failure;
491
492 /* If we are in an open segment, try merging */
493 if (segstart != s) {
494 DBG(" - trying merge...\n");
495 /* We cannot merge if:
496 * - allocated dma_addr isn't contiguous to previous allocation
497 */
498 if (novmerge || (dma_addr != dma_next) ||
499 (outs->dma_length + s->length > max_seg_size)) {
500 /* Can't merge: create a new segment */
501 segstart = s;
502 outcount++;
503 outs = sg_next(outs);
504 DBG(" can't merge, new segment.\n");
505 } else {
506 outs->dma_length += s->length;
507 DBG(" merged, new len: %ux\n", outs->dma_length);
508 }
509 }
510
511 if (segstart == s) {
512 /* This is a new segment, fill entries */
513 DBG(" - filling new segment.\n");
514 outs->dma_address = dma_addr;
515 outs->dma_length = slen;
516 }
517
518 /* Calculate next page pointer for contiguous check */
519 dma_next = dma_addr + slen;
520
521 DBG(" - dma next is: %lx\n", dma_next);
522 }
523
524 /* Flush/invalidate TLB caches if necessary */
525 if (tbl->it_ops->flush)
526 tbl->it_ops->flush(tbl);
527
528 DBG("mapped %d elements:\n", outcount);
529
530 /* For the sake of ppc_iommu_unmap_sg, we clear out the length in the
531 * next entry of the sglist if we didn't fill the list completely
532 */
533 if (outcount < incount) {
534 outs = sg_next(outs);
535 outs->dma_address = DMA_MAPPING_ERROR;
536 outs->dma_length = 0;
537 }
538
539 /* Make sure updates are seen by hardware */
540 mb();
541
542 return outcount;
543
544 failure:
545 for_each_sg(sglist, s, nelems, i) {
546 if (s->dma_length != 0) {
547 unsigned long vaddr, npages;
548
549 vaddr = s->dma_address & IOMMU_PAGE_MASK(tbl);
550 npages = iommu_num_pages(s->dma_address, s->dma_length,
551 IOMMU_PAGE_SIZE(tbl));
552 __iommu_free(tbl, vaddr, npages);
553 s->dma_address = DMA_MAPPING_ERROR;
554 s->dma_length = 0;
555 }
556 if (s == outs)
557 break;
558 }
559 return 0;
560}
561
562
563void ppc_iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
564 int nelems, enum dma_data_direction direction,
565 unsigned long attrs)
566{
567 struct scatterlist *sg;
568
569 BUG_ON(direction == DMA_NONE);
570
571 if (!tbl)
572 return;
573
574 sg = sglist;
575 while (nelems--) {
576 unsigned int npages;
577 dma_addr_t dma_handle = sg->dma_address;
578
579 if (sg->dma_length == 0)
580 break;
581 npages = iommu_num_pages(dma_handle, sg->dma_length,
582 IOMMU_PAGE_SIZE(tbl));
583 __iommu_free(tbl, dma_handle, npages);
584 sg = sg_next(sg);
585 }
586
587 /* Flush/invalidate TLBs if necessary. As for iommu_free(), we
588 * do not do an mb() here, the affected platforms do not need it
589 * when freeing.
590 */
591 if (tbl->it_ops->flush)
592 tbl->it_ops->flush(tbl);
593}
594
595static void iommu_table_clear(struct iommu_table *tbl)
596{
597 /*
598 * In case of firmware assisted dump system goes through clean
599 * reboot process at the time of system crash. Hence it's safe to
600 * clear the TCE entries if firmware assisted dump is active.
601 */
602 if (!is_kdump_kernel() || is_fadump_active()) {
603 /* Clear the table in case firmware left allocations in it */
604 tbl->it_ops->clear(tbl, tbl->it_offset, tbl->it_size);
605 return;
606 }
607
608#ifdef CONFIG_CRASH_DUMP
609 if (tbl->it_ops->get) {
610 unsigned long index, tceval, tcecount = 0;
611
612 /* Reserve the existing mappings left by the first kernel. */
613 for (index = 0; index < tbl->it_size; index++) {
614 tceval = tbl->it_ops->get(tbl, index + tbl->it_offset);
615 /*
616 * Freed TCE entry contains 0x7fffffffffffffff on JS20
617 */
618 if (tceval && (tceval != 0x7fffffffffffffffUL)) {
619 __set_bit(index, tbl->it_map);
620 tcecount++;
621 }
622 }
623
624 if ((tbl->it_size - tcecount) < KDUMP_MIN_TCE_ENTRIES) {
625 printk(KERN_WARNING "TCE table is full; freeing ");
626 printk(KERN_WARNING "%d entries for the kdump boot\n",
627 KDUMP_MIN_TCE_ENTRIES);
628 for (index = tbl->it_size - KDUMP_MIN_TCE_ENTRIES;
629 index < tbl->it_size; index++)
630 __clear_bit(index, tbl->it_map);
631 }
632 }
633#endif
634}
635
636static void iommu_table_reserve_pages(struct iommu_table *tbl,
637 unsigned long res_start, unsigned long res_end)
638{
639 int i;
640
641 WARN_ON_ONCE(res_end < res_start);
642 /*
643 * Reserve page 0 so it will not be used for any mappings.
644 * This avoids buggy drivers that consider page 0 to be invalid
645 * to crash the machine or even lose data.
646 */
647 if (tbl->it_offset == 0)
648 set_bit(0, tbl->it_map);
649
650 tbl->it_reserved_start = res_start;
651 tbl->it_reserved_end = res_end;
652
653 /* Check if res_start..res_end isn't empty and overlaps the table */
654 if (res_start && res_end &&
655 (tbl->it_offset + tbl->it_size < res_start ||
656 res_end < tbl->it_offset))
657 return;
658
659 for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
660 set_bit(i - tbl->it_offset, tbl->it_map);
661}
662
663static void iommu_table_release_pages(struct iommu_table *tbl)
664{
665 int i;
666
667 /*
668 * In case we have reserved the first bit, we should not emit
669 * the warning below.
670 */
671 if (tbl->it_offset == 0)
672 clear_bit(0, tbl->it_map);
673
674 for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
675 clear_bit(i - tbl->it_offset, tbl->it_map);
676}
677
678/*
679 * Build a iommu_table structure. This contains a bit map which
680 * is used to manage allocation of the tce space.
681 */
682struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid,
683 unsigned long res_start, unsigned long res_end)
684{
685 unsigned long sz;
686 static int welcomed = 0;
687 struct page *page;
688 unsigned int i;
689 struct iommu_pool *p;
690
691 BUG_ON(!tbl->it_ops);
692
693 /* number of bytes needed for the bitmap */
694 sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long);
695
696 page = alloc_pages_node(nid, GFP_KERNEL, get_order(sz));
697 if (!page)
698 panic("iommu_init_table: Can't allocate %ld bytes\n", sz);
699 tbl->it_map = page_address(page);
700 memset(tbl->it_map, 0, sz);
701
702 iommu_table_reserve_pages(tbl, res_start, res_end);
703
704 /* We only split the IOMMU table if we have 1GB or more of space */
705 if ((tbl->it_size << tbl->it_page_shift) >= (1UL * 1024 * 1024 * 1024))
706 tbl->nr_pools = IOMMU_NR_POOLS;
707 else
708 tbl->nr_pools = 1;
709
710 /* We reserve the top 1/4 of the table for large allocations */
711 tbl->poolsize = (tbl->it_size * 3 / 4) / tbl->nr_pools;
712
713 for (i = 0; i < tbl->nr_pools; i++) {
714 p = &tbl->pools[i];
715 spin_lock_init(&(p->lock));
716 p->start = tbl->poolsize * i;
717 p->hint = p->start;
718 p->end = p->start + tbl->poolsize;
719 }
720
721 p = &tbl->large_pool;
722 spin_lock_init(&(p->lock));
723 p->start = tbl->poolsize * i;
724 p->hint = p->start;
725 p->end = tbl->it_size;
726
727 iommu_table_clear(tbl);
728
729 if (!welcomed) {
730 printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
731 novmerge ? "disabled" : "enabled");
732 welcomed = 1;
733 }
734
735 return tbl;
736}
737
738static void iommu_table_free(struct kref *kref)
739{
740 unsigned long bitmap_sz;
741 unsigned int order;
742 struct iommu_table *tbl;
743
744 tbl = container_of(kref, struct iommu_table, it_kref);
745
746 if (tbl->it_ops->free)
747 tbl->it_ops->free(tbl);
748
749 if (!tbl->it_map) {
750 kfree(tbl);
751 return;
752 }
753
754 iommu_table_release_pages(tbl);
755
756 /* verify that table contains no entries */
757 if (!bitmap_empty(tbl->it_map, tbl->it_size))
758 pr_warn("%s: Unexpected TCEs\n", __func__);
759
760 /* calculate bitmap size in bytes */
761 bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long);
762
763 /* free bitmap */
764 order = get_order(bitmap_sz);
765 free_pages((unsigned long) tbl->it_map, order);
766
767 /* free table */
768 kfree(tbl);
769}
770
771struct iommu_table *iommu_tce_table_get(struct iommu_table *tbl)
772{
773 if (kref_get_unless_zero(&tbl->it_kref))
774 return tbl;
775
776 return NULL;
777}
778EXPORT_SYMBOL_GPL(iommu_tce_table_get);
779
780int iommu_tce_table_put(struct iommu_table *tbl)
781{
782 if (WARN_ON(!tbl))
783 return 0;
784
785 return kref_put(&tbl->it_kref, iommu_table_free);
786}
787EXPORT_SYMBOL_GPL(iommu_tce_table_put);
788
789/* Creates TCEs for a user provided buffer. The user buffer must be
790 * contiguous real kernel storage (not vmalloc). The address passed here
791 * comprises a page address and offset into that page. The dma_addr_t
792 * returned will point to the same byte within the page as was passed in.
793 */
794dma_addr_t iommu_map_page(struct device *dev, struct iommu_table *tbl,
795 struct page *page, unsigned long offset, size_t size,
796 unsigned long mask, enum dma_data_direction direction,
797 unsigned long attrs)
798{
799 dma_addr_t dma_handle = DMA_MAPPING_ERROR;
800 void *vaddr;
801 unsigned long uaddr;
802 unsigned int npages, align;
803
804 BUG_ON(direction == DMA_NONE);
805
806 vaddr = page_address(page) + offset;
807 uaddr = (unsigned long)vaddr;
808
809 if (tbl) {
810 npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl));
811 align = 0;
812 if (tbl->it_page_shift < PAGE_SHIFT && size >= PAGE_SIZE &&
813 ((unsigned long)vaddr & ~PAGE_MASK) == 0)
814 align = PAGE_SHIFT - tbl->it_page_shift;
815
816 dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction,
817 mask >> tbl->it_page_shift, align,
818 attrs);
819 if (dma_handle == DMA_MAPPING_ERROR) {
820 if (!(attrs & DMA_ATTR_NO_WARN) &&
821 printk_ratelimit()) {
822 dev_info(dev, "iommu_alloc failed, tbl %p "
823 "vaddr %p npages %d\n", tbl, vaddr,
824 npages);
825 }
826 } else
827 dma_handle |= (uaddr & ~IOMMU_PAGE_MASK(tbl));
828 }
829
830 return dma_handle;
831}
832
833void iommu_unmap_page(struct iommu_table *tbl, dma_addr_t dma_handle,
834 size_t size, enum dma_data_direction direction,
835 unsigned long attrs)
836{
837 unsigned int npages;
838
839 BUG_ON(direction == DMA_NONE);
840
841 if (tbl) {
842 npages = iommu_num_pages(dma_handle, size,
843 IOMMU_PAGE_SIZE(tbl));
844 iommu_free(tbl, dma_handle, npages);
845 }
846}
847
848/* Allocates a contiguous real buffer and creates mappings over it.
849 * Returns the virtual address of the buffer and sets dma_handle
850 * to the dma address (mapping) of the first page.
851 */
852void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
853 size_t size, dma_addr_t *dma_handle,
854 unsigned long mask, gfp_t flag, int node)
855{
856 void *ret = NULL;
857 dma_addr_t mapping;
858 unsigned int order;
859 unsigned int nio_pages, io_order;
860 struct page *page;
861
862 size = PAGE_ALIGN(size);
863 order = get_order(size);
864
865 /*
866 * Client asked for way too much space. This is checked later
867 * anyway. It is easier to debug here for the drivers than in
868 * the tce tables.
869 */
870 if (order >= IOMAP_MAX_ORDER) {
871 dev_info(dev, "iommu_alloc_consistent size too large: 0x%lx\n",
872 size);
873 return NULL;
874 }
875
876 if (!tbl)
877 return NULL;
878
879 /* Alloc enough pages (and possibly more) */
880 page = alloc_pages_node(node, flag, order);
881 if (!page)
882 return NULL;
883 ret = page_address(page);
884 memset(ret, 0, size);
885
886 /* Set up tces to cover the allocated range */
887 nio_pages = size >> tbl->it_page_shift;
888 io_order = get_iommu_order(size, tbl);
889 mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
890 mask >> tbl->it_page_shift, io_order, 0);
891 if (mapping == DMA_MAPPING_ERROR) {
892 free_pages((unsigned long)ret, order);
893 return NULL;
894 }
895 *dma_handle = mapping;
896 return ret;
897}
898
899void iommu_free_coherent(struct iommu_table *tbl, size_t size,
900 void *vaddr, dma_addr_t dma_handle)
901{
902 if (tbl) {
903 unsigned int nio_pages;
904
905 size = PAGE_ALIGN(size);
906 nio_pages = size >> tbl->it_page_shift;
907 iommu_free(tbl, dma_handle, nio_pages);
908 size = PAGE_ALIGN(size);
909 free_pages((unsigned long)vaddr, get_order(size));
910 }
911}
912
913unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir)
914{
915 switch (dir) {
916 case DMA_BIDIRECTIONAL:
917 return TCE_PCI_READ | TCE_PCI_WRITE;
918 case DMA_FROM_DEVICE:
919 return TCE_PCI_WRITE;
920 case DMA_TO_DEVICE:
921 return TCE_PCI_READ;
922 default:
923 return 0;
924 }
925}
926EXPORT_SYMBOL_GPL(iommu_direction_to_tce_perm);
927
928#ifdef CONFIG_IOMMU_API
929/*
930 * SPAPR TCE API
931 */
932static void group_release(void *iommu_data)
933{
934 struct iommu_table_group *table_group = iommu_data;
935
936 table_group->group = NULL;
937}
938
939void iommu_register_group(struct iommu_table_group *table_group,
940 int pci_domain_number, unsigned long pe_num)
941{
942 struct iommu_group *grp;
943 char *name;
944
945 grp = iommu_group_alloc();
946 if (IS_ERR(grp)) {
947 pr_warn("powerpc iommu api: cannot create new group, err=%ld\n",
948 PTR_ERR(grp));
949 return;
950 }
951 table_group->group = grp;
952 iommu_group_set_iommudata(grp, table_group, group_release);
953 name = kasprintf(GFP_KERNEL, "domain%d-pe%lx",
954 pci_domain_number, pe_num);
955 if (!name)
956 return;
957 iommu_group_set_name(grp, name);
958 kfree(name);
959}
960
961enum dma_data_direction iommu_tce_direction(unsigned long tce)
962{
963 if ((tce & TCE_PCI_READ) && (tce & TCE_PCI_WRITE))
964 return DMA_BIDIRECTIONAL;
965 else if (tce & TCE_PCI_READ)
966 return DMA_TO_DEVICE;
967 else if (tce & TCE_PCI_WRITE)
968 return DMA_FROM_DEVICE;
969 else
970 return DMA_NONE;
971}
972EXPORT_SYMBOL_GPL(iommu_tce_direction);
973
974void iommu_flush_tce(struct iommu_table *tbl)
975{
976 /* Flush/invalidate TLB caches if necessary */
977 if (tbl->it_ops->flush)
978 tbl->it_ops->flush(tbl);
979
980 /* Make sure updates are seen by hardware */
981 mb();
982}
983EXPORT_SYMBOL_GPL(iommu_flush_tce);
984
985int iommu_tce_check_ioba(unsigned long page_shift,
986 unsigned long offset, unsigned long size,
987 unsigned long ioba, unsigned long npages)
988{
989 unsigned long mask = (1UL << page_shift) - 1;
990
991 if (ioba & mask)
992 return -EINVAL;
993
994 ioba >>= page_shift;
995 if (ioba < offset)
996 return -EINVAL;
997
998 if ((ioba + 1) > (offset + size))
999 return -EINVAL;
1000
1001 return 0;
1002}
1003EXPORT_SYMBOL_GPL(iommu_tce_check_ioba);
1004
1005int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa)
1006{
1007 unsigned long mask = (1UL << page_shift) - 1;
1008
1009 if (gpa & mask)
1010 return -EINVAL;
1011
1012 return 0;
1013}
1014EXPORT_SYMBOL_GPL(iommu_tce_check_gpa);
1015
1016extern long iommu_tce_xchg_no_kill(struct mm_struct *mm,
1017 struct iommu_table *tbl,
1018 unsigned long entry, unsigned long *hpa,
1019 enum dma_data_direction *direction)
1020{
1021 long ret;
1022 unsigned long size = 0;
1023
1024 ret = tbl->it_ops->xchg_no_kill(tbl, entry, hpa, direction, false);
1025 if (!ret && ((*direction == DMA_FROM_DEVICE) ||
1026 (*direction == DMA_BIDIRECTIONAL)) &&
1027 !mm_iommu_is_devmem(mm, *hpa, tbl->it_page_shift,
1028 &size))
1029 SetPageDirty(pfn_to_page(*hpa >> PAGE_SHIFT));
1030
1031 return ret;
1032}
1033EXPORT_SYMBOL_GPL(iommu_tce_xchg_no_kill);
1034
1035void iommu_tce_kill(struct iommu_table *tbl,
1036 unsigned long entry, unsigned long pages)
1037{
1038 if (tbl->it_ops->tce_kill)
1039 tbl->it_ops->tce_kill(tbl, entry, pages, false);
1040}
1041EXPORT_SYMBOL_GPL(iommu_tce_kill);
1042
1043int iommu_take_ownership(struct iommu_table *tbl)
1044{
1045 unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
1046 int ret = 0;
1047
1048 /*
1049 * VFIO does not control TCE entries allocation and the guest
1050 * can write new TCEs on top of existing ones so iommu_tce_build()
1051 * must be able to release old pages. This functionality
1052 * requires exchange() callback defined so if it is not
1053 * implemented, we disallow taking ownership over the table.
1054 */
1055 if (!tbl->it_ops->xchg_no_kill)
1056 return -EINVAL;
1057
1058 spin_lock_irqsave(&tbl->large_pool.lock, flags);
1059 for (i = 0; i < tbl->nr_pools; i++)
1060 spin_lock(&tbl->pools[i].lock);
1061
1062 iommu_table_release_pages(tbl);
1063
1064 if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
1065 pr_err("iommu_tce: it_map is not empty");
1066 ret = -EBUSY;
1067 /* Undo iommu_table_release_pages, i.e. restore bit#0, etc */
1068 iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
1069 tbl->it_reserved_end);
1070 } else {
1071 memset(tbl->it_map, 0xff, sz);
1072 }
1073
1074 for (i = 0; i < tbl->nr_pools; i++)
1075 spin_unlock(&tbl->pools[i].lock);
1076 spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
1077
1078 return ret;
1079}
1080EXPORT_SYMBOL_GPL(iommu_take_ownership);
1081
1082void iommu_release_ownership(struct iommu_table *tbl)
1083{
1084 unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
1085
1086 spin_lock_irqsave(&tbl->large_pool.lock, flags);
1087 for (i = 0; i < tbl->nr_pools; i++)
1088 spin_lock(&tbl->pools[i].lock);
1089
1090 memset(tbl->it_map, 0, sz);
1091
1092 iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
1093 tbl->it_reserved_end);
1094
1095 for (i = 0; i < tbl->nr_pools; i++)
1096 spin_unlock(&tbl->pools[i].lock);
1097 spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
1098}
1099EXPORT_SYMBOL_GPL(iommu_release_ownership);
1100
1101int iommu_add_device(struct iommu_table_group *table_group, struct device *dev)
1102{
1103 /*
1104 * The sysfs entries should be populated before
1105 * binding IOMMU group. If sysfs entries isn't
1106 * ready, we simply bail.
1107 */
1108 if (!device_is_registered(dev))
1109 return -ENOENT;
1110
1111 if (device_iommu_mapped(dev)) {
1112 pr_debug("%s: Skipping device %s with iommu group %d\n",
1113 __func__, dev_name(dev),
1114 iommu_group_id(dev->iommu_group));
1115 return -EBUSY;
1116 }
1117
1118 pr_debug("%s: Adding %s to iommu group %d\n",
1119 __func__, dev_name(dev), iommu_group_id(table_group->group));
1120
1121 return iommu_group_add_device(table_group->group, dev);
1122}
1123EXPORT_SYMBOL_GPL(iommu_add_device);
1124
1125void iommu_del_device(struct device *dev)
1126{
1127 /*
1128 * Some devices might not have IOMMU table and group
1129 * and we needn't detach them from the associated
1130 * IOMMU groups
1131 */
1132 if (!device_iommu_mapped(dev)) {
1133 pr_debug("iommu_tce: skipping device %s with no tbl\n",
1134 dev_name(dev));
1135 return;
1136 }
1137
1138 iommu_group_remove_device(dev);
1139}
1140EXPORT_SYMBOL_GPL(iommu_del_device);
1141#endif /* CONFIG_IOMMU_API */
1/*
2 * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
3 *
4 * Rewrite, cleanup, new allocation schemes, virtual merging:
5 * Copyright (C) 2004 Olof Johansson, IBM Corporation
6 * and Ben. Herrenschmidt, IBM Corporation
7 *
8 * Dynamic DMA mapping support, bus-independent parts.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25
26#include <linux/init.h>
27#include <linux/types.h>
28#include <linux/slab.h>
29#include <linux/mm.h>
30#include <linux/spinlock.h>
31#include <linux/string.h>
32#include <linux/dma-mapping.h>
33#include <linux/bitmap.h>
34#include <linux/iommu-helper.h>
35#include <linux/crash_dump.h>
36#include <asm/io.h>
37#include <asm/prom.h>
38#include <asm/iommu.h>
39#include <asm/pci-bridge.h>
40#include <asm/machdep.h>
41#include <asm/kdump.h>
42#include <asm/fadump.h>
43
44#define DBG(...)
45
46static int novmerge;
47
48static void __iommu_free(struct iommu_table *, dma_addr_t, unsigned int);
49
50static int __init setup_iommu(char *str)
51{
52 if (!strcmp(str, "novmerge"))
53 novmerge = 1;
54 else if (!strcmp(str, "vmerge"))
55 novmerge = 0;
56 return 1;
57}
58
59__setup("iommu=", setup_iommu);
60
61static unsigned long iommu_range_alloc(struct device *dev,
62 struct iommu_table *tbl,
63 unsigned long npages,
64 unsigned long *handle,
65 unsigned long mask,
66 unsigned int align_order)
67{
68 unsigned long n, end, start;
69 unsigned long limit;
70 int largealloc = npages > 15;
71 int pass = 0;
72 unsigned long align_mask;
73 unsigned long boundary_size;
74
75 align_mask = 0xffffffffffffffffl >> (64 - align_order);
76
77 /* This allocator was derived from x86_64's bit string search */
78
79 /* Sanity check */
80 if (unlikely(npages == 0)) {
81 if (printk_ratelimit())
82 WARN_ON(1);
83 return DMA_ERROR_CODE;
84 }
85
86 if (handle && *handle)
87 start = *handle;
88 else
89 start = largealloc ? tbl->it_largehint : tbl->it_hint;
90
91 /* Use only half of the table for small allocs (15 pages or less) */
92 limit = largealloc ? tbl->it_size : tbl->it_halfpoint;
93
94 if (largealloc && start < tbl->it_halfpoint)
95 start = tbl->it_halfpoint;
96
97 /* The case below can happen if we have a small segment appended
98 * to a large, or when the previous alloc was at the very end of
99 * the available space. If so, go back to the initial start.
100 */
101 if (start >= limit)
102 start = largealloc ? tbl->it_largehint : tbl->it_hint;
103
104 again:
105
106 if (limit + tbl->it_offset > mask) {
107 limit = mask - tbl->it_offset + 1;
108 /* If we're constrained on address range, first try
109 * at the masked hint to avoid O(n) search complexity,
110 * but on second pass, start at 0.
111 */
112 if ((start & mask) >= limit || pass > 0)
113 start = 0;
114 else
115 start &= mask;
116 }
117
118 if (dev)
119 boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
120 1 << IOMMU_PAGE_SHIFT);
121 else
122 boundary_size = ALIGN(1UL << 32, 1 << IOMMU_PAGE_SHIFT);
123 /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */
124
125 n = iommu_area_alloc(tbl->it_map, limit, start, npages,
126 tbl->it_offset, boundary_size >> IOMMU_PAGE_SHIFT,
127 align_mask);
128 if (n == -1) {
129 if (likely(pass < 2)) {
130 /* First failure, just rescan the half of the table.
131 * Second failure, rescan the other half of the table.
132 */
133 start = (largealloc ^ pass) ? tbl->it_halfpoint : 0;
134 limit = pass ? tbl->it_size : limit;
135 pass++;
136 goto again;
137 } else {
138 /* Third failure, give up */
139 return DMA_ERROR_CODE;
140 }
141 }
142
143 end = n + npages;
144
145 /* Bump the hint to a new block for small allocs. */
146 if (largealloc) {
147 /* Don't bump to new block to avoid fragmentation */
148 tbl->it_largehint = end;
149 } else {
150 /* Overflow will be taken care of at the next allocation */
151 tbl->it_hint = (end + tbl->it_blocksize - 1) &
152 ~(tbl->it_blocksize - 1);
153 }
154
155 /* Update handle for SG allocations */
156 if (handle)
157 *handle = end;
158
159 return n;
160}
161
162static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
163 void *page, unsigned int npages,
164 enum dma_data_direction direction,
165 unsigned long mask, unsigned int align_order,
166 struct dma_attrs *attrs)
167{
168 unsigned long entry, flags;
169 dma_addr_t ret = DMA_ERROR_CODE;
170 int build_fail;
171
172 spin_lock_irqsave(&(tbl->it_lock), flags);
173
174 entry = iommu_range_alloc(dev, tbl, npages, NULL, mask, align_order);
175
176 if (unlikely(entry == DMA_ERROR_CODE)) {
177 spin_unlock_irqrestore(&(tbl->it_lock), flags);
178 return DMA_ERROR_CODE;
179 }
180
181 entry += tbl->it_offset; /* Offset into real TCE table */
182 ret = entry << IOMMU_PAGE_SHIFT; /* Set the return dma address */
183
184 /* Put the TCEs in the HW table */
185 build_fail = ppc_md.tce_build(tbl, entry, npages,
186 (unsigned long)page & IOMMU_PAGE_MASK,
187 direction, attrs);
188
189 /* ppc_md.tce_build() only returns non-zero for transient errors.
190 * Clean up the table bitmap in this case and return
191 * DMA_ERROR_CODE. For all other errors the functionality is
192 * not altered.
193 */
194 if (unlikely(build_fail)) {
195 __iommu_free(tbl, ret, npages);
196
197 spin_unlock_irqrestore(&(tbl->it_lock), flags);
198 return DMA_ERROR_CODE;
199 }
200
201 /* Flush/invalidate TLB caches if necessary */
202 if (ppc_md.tce_flush)
203 ppc_md.tce_flush(tbl);
204
205 spin_unlock_irqrestore(&(tbl->it_lock), flags);
206
207 /* Make sure updates are seen by hardware */
208 mb();
209
210 return ret;
211}
212
213static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
214 unsigned int npages)
215{
216 unsigned long entry, free_entry;
217
218 entry = dma_addr >> IOMMU_PAGE_SHIFT;
219 free_entry = entry - tbl->it_offset;
220
221 if (((free_entry + npages) > tbl->it_size) ||
222 (entry < tbl->it_offset)) {
223 if (printk_ratelimit()) {
224 printk(KERN_INFO "iommu_free: invalid entry\n");
225 printk(KERN_INFO "\tentry = 0x%lx\n", entry);
226 printk(KERN_INFO "\tdma_addr = 0x%llx\n", (u64)dma_addr);
227 printk(KERN_INFO "\tTable = 0x%llx\n", (u64)tbl);
228 printk(KERN_INFO "\tbus# = 0x%llx\n", (u64)tbl->it_busno);
229 printk(KERN_INFO "\tsize = 0x%llx\n", (u64)tbl->it_size);
230 printk(KERN_INFO "\tstartOff = 0x%llx\n", (u64)tbl->it_offset);
231 printk(KERN_INFO "\tindex = 0x%llx\n", (u64)tbl->it_index);
232 WARN_ON(1);
233 }
234 return;
235 }
236
237 ppc_md.tce_free(tbl, entry, npages);
238 bitmap_clear(tbl->it_map, free_entry, npages);
239}
240
241static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
242 unsigned int npages)
243{
244 unsigned long flags;
245
246 spin_lock_irqsave(&(tbl->it_lock), flags);
247
248 __iommu_free(tbl, dma_addr, npages);
249
250 /* Make sure TLB cache is flushed if the HW needs it. We do
251 * not do an mb() here on purpose, it is not needed on any of
252 * the current platforms.
253 */
254 if (ppc_md.tce_flush)
255 ppc_md.tce_flush(tbl);
256
257 spin_unlock_irqrestore(&(tbl->it_lock), flags);
258}
259
260int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
261 struct scatterlist *sglist, int nelems,
262 unsigned long mask, enum dma_data_direction direction,
263 struct dma_attrs *attrs)
264{
265 dma_addr_t dma_next = 0, dma_addr;
266 unsigned long flags;
267 struct scatterlist *s, *outs, *segstart;
268 int outcount, incount, i, build_fail = 0;
269 unsigned int align;
270 unsigned long handle;
271 unsigned int max_seg_size;
272
273 BUG_ON(direction == DMA_NONE);
274
275 if ((nelems == 0) || !tbl)
276 return 0;
277
278 outs = s = segstart = &sglist[0];
279 outcount = 1;
280 incount = nelems;
281 handle = 0;
282
283 /* Init first segment length for backout at failure */
284 outs->dma_length = 0;
285
286 DBG("sg mapping %d elements:\n", nelems);
287
288 spin_lock_irqsave(&(tbl->it_lock), flags);
289
290 max_seg_size = dma_get_max_seg_size(dev);
291 for_each_sg(sglist, s, nelems, i) {
292 unsigned long vaddr, npages, entry, slen;
293
294 slen = s->length;
295 /* Sanity check */
296 if (slen == 0) {
297 dma_next = 0;
298 continue;
299 }
300 /* Allocate iommu entries for that segment */
301 vaddr = (unsigned long) sg_virt(s);
302 npages = iommu_num_pages(vaddr, slen, IOMMU_PAGE_SIZE);
303 align = 0;
304 if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && slen >= PAGE_SIZE &&
305 (vaddr & ~PAGE_MASK) == 0)
306 align = PAGE_SHIFT - IOMMU_PAGE_SHIFT;
307 entry = iommu_range_alloc(dev, tbl, npages, &handle,
308 mask >> IOMMU_PAGE_SHIFT, align);
309
310 DBG(" - vaddr: %lx, size: %lx\n", vaddr, slen);
311
312 /* Handle failure */
313 if (unlikely(entry == DMA_ERROR_CODE)) {
314 if (printk_ratelimit())
315 dev_info(dev, "iommu_alloc failed, tbl %p "
316 "vaddr %lx npages %lu\n", tbl, vaddr,
317 npages);
318 goto failure;
319 }
320
321 /* Convert entry to a dma_addr_t */
322 entry += tbl->it_offset;
323 dma_addr = entry << IOMMU_PAGE_SHIFT;
324 dma_addr |= (s->offset & ~IOMMU_PAGE_MASK);
325
326 DBG(" - %lu pages, entry: %lx, dma_addr: %lx\n",
327 npages, entry, dma_addr);
328
329 /* Insert into HW table */
330 build_fail = ppc_md.tce_build(tbl, entry, npages,
331 vaddr & IOMMU_PAGE_MASK,
332 direction, attrs);
333 if(unlikely(build_fail))
334 goto failure;
335
336 /* If we are in an open segment, try merging */
337 if (segstart != s) {
338 DBG(" - trying merge...\n");
339 /* We cannot merge if:
340 * - allocated dma_addr isn't contiguous to previous allocation
341 */
342 if (novmerge || (dma_addr != dma_next) ||
343 (outs->dma_length + s->length > max_seg_size)) {
344 /* Can't merge: create a new segment */
345 segstart = s;
346 outcount++;
347 outs = sg_next(outs);
348 DBG(" can't merge, new segment.\n");
349 } else {
350 outs->dma_length += s->length;
351 DBG(" merged, new len: %ux\n", outs->dma_length);
352 }
353 }
354
355 if (segstart == s) {
356 /* This is a new segment, fill entries */
357 DBG(" - filling new segment.\n");
358 outs->dma_address = dma_addr;
359 outs->dma_length = slen;
360 }
361
362 /* Calculate next page pointer for contiguous check */
363 dma_next = dma_addr + slen;
364
365 DBG(" - dma next is: %lx\n", dma_next);
366 }
367
368 /* Flush/invalidate TLB caches if necessary */
369 if (ppc_md.tce_flush)
370 ppc_md.tce_flush(tbl);
371
372 spin_unlock_irqrestore(&(tbl->it_lock), flags);
373
374 DBG("mapped %d elements:\n", outcount);
375
376 /* For the sake of iommu_unmap_sg, we clear out the length in the
377 * next entry of the sglist if we didn't fill the list completely
378 */
379 if (outcount < incount) {
380 outs = sg_next(outs);
381 outs->dma_address = DMA_ERROR_CODE;
382 outs->dma_length = 0;
383 }
384
385 /* Make sure updates are seen by hardware */
386 mb();
387
388 return outcount;
389
390 failure:
391 for_each_sg(sglist, s, nelems, i) {
392 if (s->dma_length != 0) {
393 unsigned long vaddr, npages;
394
395 vaddr = s->dma_address & IOMMU_PAGE_MASK;
396 npages = iommu_num_pages(s->dma_address, s->dma_length,
397 IOMMU_PAGE_SIZE);
398 __iommu_free(tbl, vaddr, npages);
399 s->dma_address = DMA_ERROR_CODE;
400 s->dma_length = 0;
401 }
402 if (s == outs)
403 break;
404 }
405 spin_unlock_irqrestore(&(tbl->it_lock), flags);
406 return 0;
407}
408
409
410void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,
411 int nelems, enum dma_data_direction direction,
412 struct dma_attrs *attrs)
413{
414 struct scatterlist *sg;
415 unsigned long flags;
416
417 BUG_ON(direction == DMA_NONE);
418
419 if (!tbl)
420 return;
421
422 spin_lock_irqsave(&(tbl->it_lock), flags);
423
424 sg = sglist;
425 while (nelems--) {
426 unsigned int npages;
427 dma_addr_t dma_handle = sg->dma_address;
428
429 if (sg->dma_length == 0)
430 break;
431 npages = iommu_num_pages(dma_handle, sg->dma_length,
432 IOMMU_PAGE_SIZE);
433 __iommu_free(tbl, dma_handle, npages);
434 sg = sg_next(sg);
435 }
436
437 /* Flush/invalidate TLBs if necessary. As for iommu_free(), we
438 * do not do an mb() here, the affected platforms do not need it
439 * when freeing.
440 */
441 if (ppc_md.tce_flush)
442 ppc_md.tce_flush(tbl);
443
444 spin_unlock_irqrestore(&(tbl->it_lock), flags);
445}
446
447static void iommu_table_clear(struct iommu_table *tbl)
448{
449 /*
450 * In case of firmware assisted dump system goes through clean
451 * reboot process at the time of system crash. Hence it's safe to
452 * clear the TCE entries if firmware assisted dump is active.
453 */
454 if (!is_kdump_kernel() || is_fadump_active()) {
455 /* Clear the table in case firmware left allocations in it */
456 ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size);
457 return;
458 }
459
460#ifdef CONFIG_CRASH_DUMP
461 if (ppc_md.tce_get) {
462 unsigned long index, tceval, tcecount = 0;
463
464 /* Reserve the existing mappings left by the first kernel. */
465 for (index = 0; index < tbl->it_size; index++) {
466 tceval = ppc_md.tce_get(tbl, index + tbl->it_offset);
467 /*
468 * Freed TCE entry contains 0x7fffffffffffffff on JS20
469 */
470 if (tceval && (tceval != 0x7fffffffffffffffUL)) {
471 __set_bit(index, tbl->it_map);
472 tcecount++;
473 }
474 }
475
476 if ((tbl->it_size - tcecount) < KDUMP_MIN_TCE_ENTRIES) {
477 printk(KERN_WARNING "TCE table is full; freeing ");
478 printk(KERN_WARNING "%d entries for the kdump boot\n",
479 KDUMP_MIN_TCE_ENTRIES);
480 for (index = tbl->it_size - KDUMP_MIN_TCE_ENTRIES;
481 index < tbl->it_size; index++)
482 __clear_bit(index, tbl->it_map);
483 }
484 }
485#endif
486}
487
488/*
489 * Build a iommu_table structure. This contains a bit map which
490 * is used to manage allocation of the tce space.
491 */
492struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
493{
494 unsigned long sz;
495 static int welcomed = 0;
496 struct page *page;
497
498 /* Set aside 1/4 of the table for large allocations. */
499 tbl->it_halfpoint = tbl->it_size * 3 / 4;
500
501 /* number of bytes needed for the bitmap */
502 sz = (tbl->it_size + 7) >> 3;
503
504 page = alloc_pages_node(nid, GFP_ATOMIC, get_order(sz));
505 if (!page)
506 panic("iommu_init_table: Can't allocate %ld bytes\n", sz);
507 tbl->it_map = page_address(page);
508 memset(tbl->it_map, 0, sz);
509
510 /*
511 * Reserve page 0 so it will not be used for any mappings.
512 * This avoids buggy drivers that consider page 0 to be invalid
513 * to crash the machine or even lose data.
514 */
515 if (tbl->it_offset == 0)
516 set_bit(0, tbl->it_map);
517
518 tbl->it_hint = 0;
519 tbl->it_largehint = tbl->it_halfpoint;
520 spin_lock_init(&tbl->it_lock);
521
522 iommu_table_clear(tbl);
523
524 if (!welcomed) {
525 printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n",
526 novmerge ? "disabled" : "enabled");
527 welcomed = 1;
528 }
529
530 return tbl;
531}
532
533void iommu_free_table(struct iommu_table *tbl, const char *node_name)
534{
535 unsigned long bitmap_sz, i;
536 unsigned int order;
537
538 if (!tbl || !tbl->it_map) {
539 printk(KERN_ERR "%s: expected TCE map for %s\n", __func__,
540 node_name);
541 return;
542 }
543
544 /* verify that table contains no entries */
545 /* it_size is in entries, and we're examining 64 at a time */
546 for (i = 0; i < (tbl->it_size/64); i++) {
547 if (tbl->it_map[i] != 0) {
548 printk(KERN_WARNING "%s: Unexpected TCEs for %s\n",
549 __func__, node_name);
550 break;
551 }
552 }
553
554 /* calculate bitmap size in bytes */
555 bitmap_sz = (tbl->it_size + 7) / 8;
556
557 /* free bitmap */
558 order = get_order(bitmap_sz);
559 free_pages((unsigned long) tbl->it_map, order);
560
561 /* free table */
562 kfree(tbl);
563}
564
565/* Creates TCEs for a user provided buffer. The user buffer must be
566 * contiguous real kernel storage (not vmalloc). The address passed here
567 * comprises a page address and offset into that page. The dma_addr_t
568 * returned will point to the same byte within the page as was passed in.
569 */
570dma_addr_t iommu_map_page(struct device *dev, struct iommu_table *tbl,
571 struct page *page, unsigned long offset, size_t size,
572 unsigned long mask, enum dma_data_direction direction,
573 struct dma_attrs *attrs)
574{
575 dma_addr_t dma_handle = DMA_ERROR_CODE;
576 void *vaddr;
577 unsigned long uaddr;
578 unsigned int npages, align;
579
580 BUG_ON(direction == DMA_NONE);
581
582 vaddr = page_address(page) + offset;
583 uaddr = (unsigned long)vaddr;
584 npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE);
585
586 if (tbl) {
587 align = 0;
588 if (IOMMU_PAGE_SHIFT < PAGE_SHIFT && size >= PAGE_SIZE &&
589 ((unsigned long)vaddr & ~PAGE_MASK) == 0)
590 align = PAGE_SHIFT - IOMMU_PAGE_SHIFT;
591
592 dma_handle = iommu_alloc(dev, tbl, vaddr, npages, direction,
593 mask >> IOMMU_PAGE_SHIFT, align,
594 attrs);
595 if (dma_handle == DMA_ERROR_CODE) {
596 if (printk_ratelimit()) {
597 dev_info(dev, "iommu_alloc failed, tbl %p "
598 "vaddr %p npages %d\n", tbl, vaddr,
599 npages);
600 }
601 } else
602 dma_handle |= (uaddr & ~IOMMU_PAGE_MASK);
603 }
604
605 return dma_handle;
606}
607
608void iommu_unmap_page(struct iommu_table *tbl, dma_addr_t dma_handle,
609 size_t size, enum dma_data_direction direction,
610 struct dma_attrs *attrs)
611{
612 unsigned int npages;
613
614 BUG_ON(direction == DMA_NONE);
615
616 if (tbl) {
617 npages = iommu_num_pages(dma_handle, size, IOMMU_PAGE_SIZE);
618 iommu_free(tbl, dma_handle, npages);
619 }
620}
621
622/* Allocates a contiguous real buffer and creates mappings over it.
623 * Returns the virtual address of the buffer and sets dma_handle
624 * to the dma address (mapping) of the first page.
625 */
626void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
627 size_t size, dma_addr_t *dma_handle,
628 unsigned long mask, gfp_t flag, int node)
629{
630 void *ret = NULL;
631 dma_addr_t mapping;
632 unsigned int order;
633 unsigned int nio_pages, io_order;
634 struct page *page;
635
636 size = PAGE_ALIGN(size);
637 order = get_order(size);
638
639 /*
640 * Client asked for way too much space. This is checked later
641 * anyway. It is easier to debug here for the drivers than in
642 * the tce tables.
643 */
644 if (order >= IOMAP_MAX_ORDER) {
645 dev_info(dev, "iommu_alloc_consistent size too large: 0x%lx\n",
646 size);
647 return NULL;
648 }
649
650 if (!tbl)
651 return NULL;
652
653 /* Alloc enough pages (and possibly more) */
654 page = alloc_pages_node(node, flag, order);
655 if (!page)
656 return NULL;
657 ret = page_address(page);
658 memset(ret, 0, size);
659
660 /* Set up tces to cover the allocated range */
661 nio_pages = size >> IOMMU_PAGE_SHIFT;
662 io_order = get_iommu_order(size);
663 mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
664 mask >> IOMMU_PAGE_SHIFT, io_order, NULL);
665 if (mapping == DMA_ERROR_CODE) {
666 free_pages((unsigned long)ret, order);
667 return NULL;
668 }
669 *dma_handle = mapping;
670 return ret;
671}
672
673void iommu_free_coherent(struct iommu_table *tbl, size_t size,
674 void *vaddr, dma_addr_t dma_handle)
675{
676 if (tbl) {
677 unsigned int nio_pages;
678
679 size = PAGE_ALIGN(size);
680 nio_pages = size >> IOMMU_PAGE_SHIFT;
681 iommu_free(tbl, dma_handle, nio_pages);
682 size = PAGE_ALIGN(size);
683 free_pages((unsigned long)vaddr, get_order(size));
684 }
685}