xref: /openbmc/linux/arch/sparc/kernel/iommu.c (revision 7dd65feb)
1 /* iommu.c: Generic sparc64 IOMMU support.
2  *
3  * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
4  * Copyright (C) 1999, 2000 Jakub Jelinek (jakub@redhat.com)
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/delay.h>
10 #include <linux/device.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/errno.h>
13 #include <linux/iommu-helper.h>
14 #include <linux/bitmap.h>
15 
16 #ifdef CONFIG_PCI
17 #include <linux/pci.h>
18 #endif
19 
20 #include <asm/iommu.h>
21 
22 #include "iommu_common.h"
23 
24 #define STC_CTXMATCH_ADDR(STC, CTX)	\
25 	((STC)->strbuf_ctxmatch_base + ((CTX) << 3))
26 #define STC_FLUSHFLAG_INIT(STC) \
27 	(*((STC)->strbuf_flushflag) = 0UL)
28 #define STC_FLUSHFLAG_SET(STC) \
29 	(*((STC)->strbuf_flushflag) != 0UL)
30 
31 #define iommu_read(__reg) \
32 ({	u64 __ret; \
33 	__asm__ __volatile__("ldxa [%1] %2, %0" \
34 			     : "=r" (__ret) \
35 			     : "r" (__reg), "i" (ASI_PHYS_BYPASS_EC_E) \
36 			     : "memory"); \
37 	__ret; \
38 })
39 #define iommu_write(__reg, __val) \
40 	__asm__ __volatile__("stxa %0, [%1] %2" \
41 			     : /* no outputs */ \
42 			     : "r" (__val), "r" (__reg), \
43 			       "i" (ASI_PHYS_BYPASS_EC_E))
44 
45 /* Must be invoked under the IOMMU lock. */
46 static void iommu_flushall(struct iommu *iommu)
47 {
48 	if (iommu->iommu_flushinv) {
49 		iommu_write(iommu->iommu_flushinv, ~(u64)0);
50 	} else {
51 		unsigned long tag;
52 		int entry;
53 
54 		tag = iommu->iommu_tags;
55 		for (entry = 0; entry < 16; entry++) {
56 			iommu_write(tag, 0);
57 			tag += 8;
58 		}
59 
60 		/* Ensure completion of previous PIO writes. */
61 		(void) iommu_read(iommu->write_complete_reg);
62 	}
63 }
64 
65 #define IOPTE_CONSISTENT(CTX) \
66 	(IOPTE_VALID | IOPTE_CACHE | \
67 	 (((CTX) << 47) & IOPTE_CONTEXT))
68 
69 #define IOPTE_STREAMING(CTX) \
70 	(IOPTE_CONSISTENT(CTX) | IOPTE_STBUF)
71 
72 /* Existing mappings are never marked invalid, instead they
73  * are pointed to a dummy page.
74  */
75 #define IOPTE_IS_DUMMY(iommu, iopte)	\
76 	((iopte_val(*iopte) & IOPTE_PAGE) == (iommu)->dummy_page_pa)
77 
78 static inline void iopte_make_dummy(struct iommu *iommu, iopte_t *iopte)
79 {
80 	unsigned long val = iopte_val(*iopte);
81 
82 	val &= ~IOPTE_PAGE;
83 	val |= iommu->dummy_page_pa;
84 
85 	iopte_val(*iopte) = val;
86 }
87 
88 /* Based almost entirely upon the ppc64 iommu allocator.  If you use the 'handle'
89  * facility it must all be done in one pass while under the iommu lock.
90  *
91  * On sun4u platforms, we only flush the IOMMU once every time we've passed
92  * over the entire page table doing allocations.  Therefore we only ever advance
93  * the hint and cannot backtrack it.
94  */
95 unsigned long iommu_range_alloc(struct device *dev,
96 				struct iommu *iommu,
97 				unsigned long npages,
98 				unsigned long *handle)
99 {
100 	unsigned long n, end, start, limit, boundary_size;
101 	struct iommu_arena *arena = &iommu->arena;
102 	int pass = 0;
103 
104 	/* This allocator was derived from x86_64's bit string search */
105 
106 	/* Sanity check */
107 	if (unlikely(npages == 0)) {
108 		if (printk_ratelimit())
109 			WARN_ON(1);
110 		return DMA_ERROR_CODE;
111 	}
112 
113 	if (handle && *handle)
114 		start = *handle;
115 	else
116 		start = arena->hint;
117 
118 	limit = arena->limit;
119 
120 	/* The case below can happen if we have a small segment appended
121 	 * to a large, or when the previous alloc was at the very end of
122 	 * the available space. If so, go back to the beginning and flush.
123 	 */
124 	if (start >= limit) {
125 		start = 0;
126 		if (iommu->flush_all)
127 			iommu->flush_all(iommu);
128 	}
129 
130  again:
131 
132 	if (dev)
133 		boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
134 				      1 << IO_PAGE_SHIFT);
135 	else
136 		boundary_size = ALIGN(1UL << 32, 1 << IO_PAGE_SHIFT);
137 
138 	n = iommu_area_alloc(arena->map, limit, start, npages,
139 			     iommu->page_table_map_base >> IO_PAGE_SHIFT,
140 			     boundary_size >> IO_PAGE_SHIFT, 0);
141 	if (n == -1) {
142 		if (likely(pass < 1)) {
143 			/* First failure, rescan from the beginning.  */
144 			start = 0;
145 			if (iommu->flush_all)
146 				iommu->flush_all(iommu);
147 			pass++;
148 			goto again;
149 		} else {
150 			/* Second failure, give up */
151 			return DMA_ERROR_CODE;
152 		}
153 	}
154 
155 	end = n + npages;
156 
157 	arena->hint = end;
158 
159 	/* Update handle for SG allocations */
160 	if (handle)
161 		*handle = end;
162 
163 	return n;
164 }
165 
166 void iommu_range_free(struct iommu *iommu, dma_addr_t dma_addr, unsigned long npages)
167 {
168 	struct iommu_arena *arena = &iommu->arena;
169 	unsigned long entry;
170 
171 	entry = (dma_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT;
172 
173 	bitmap_clear(arena->map, entry, npages);
174 }
175 
176 int iommu_table_init(struct iommu *iommu, int tsbsize,
177 		     u32 dma_offset, u32 dma_addr_mask,
178 		     int numa_node)
179 {
180 	unsigned long i, order, sz, num_tsb_entries;
181 	struct page *page;
182 
183 	num_tsb_entries = tsbsize / sizeof(iopte_t);
184 
185 	/* Setup initial software IOMMU state. */
186 	spin_lock_init(&iommu->lock);
187 	iommu->ctx_lowest_free = 1;
188 	iommu->page_table_map_base = dma_offset;
189 	iommu->dma_addr_mask = dma_addr_mask;
190 
191 	/* Allocate and initialize the free area map.  */
192 	sz = num_tsb_entries / 8;
193 	sz = (sz + 7UL) & ~7UL;
194 	iommu->arena.map = kmalloc_node(sz, GFP_KERNEL, numa_node);
195 	if (!iommu->arena.map) {
196 		printk(KERN_ERR "IOMMU: Error, kmalloc(arena.map) failed.\n");
197 		return -ENOMEM;
198 	}
199 	memset(iommu->arena.map, 0, sz);
200 	iommu->arena.limit = num_tsb_entries;
201 
202 	if (tlb_type != hypervisor)
203 		iommu->flush_all = iommu_flushall;
204 
205 	/* Allocate and initialize the dummy page which we
206 	 * set inactive IO PTEs to point to.
207 	 */
208 	page = alloc_pages_node(numa_node, GFP_KERNEL, 0);
209 	if (!page) {
210 		printk(KERN_ERR "IOMMU: Error, gfp(dummy_page) failed.\n");
211 		goto out_free_map;
212 	}
213 	iommu->dummy_page = (unsigned long) page_address(page);
214 	memset((void *)iommu->dummy_page, 0, PAGE_SIZE);
215 	iommu->dummy_page_pa = (unsigned long) __pa(iommu->dummy_page);
216 
217 	/* Now allocate and setup the IOMMU page table itself.  */
218 	order = get_order(tsbsize);
219 	page = alloc_pages_node(numa_node, GFP_KERNEL, order);
220 	if (!page) {
221 		printk(KERN_ERR "IOMMU: Error, gfp(tsb) failed.\n");
222 		goto out_free_dummy_page;
223 	}
224 	iommu->page_table = (iopte_t *)page_address(page);
225 
226 	for (i = 0; i < num_tsb_entries; i++)
227 		iopte_make_dummy(iommu, &iommu->page_table[i]);
228 
229 	return 0;
230 
231 out_free_dummy_page:
232 	free_page(iommu->dummy_page);
233 	iommu->dummy_page = 0UL;
234 
235 out_free_map:
236 	kfree(iommu->arena.map);
237 	iommu->arena.map = NULL;
238 
239 	return -ENOMEM;
240 }
241 
242 static inline iopte_t *alloc_npages(struct device *dev, struct iommu *iommu,
243 				    unsigned long npages)
244 {
245 	unsigned long entry;
246 
247 	entry = iommu_range_alloc(dev, iommu, npages, NULL);
248 	if (unlikely(entry == DMA_ERROR_CODE))
249 		return NULL;
250 
251 	return iommu->page_table + entry;
252 }
253 
254 static int iommu_alloc_ctx(struct iommu *iommu)
255 {
256 	int lowest = iommu->ctx_lowest_free;
257 	int sz = IOMMU_NUM_CTXS - lowest;
258 	int n = find_next_zero_bit(iommu->ctx_bitmap, sz, lowest);
259 
260 	if (unlikely(n == sz)) {
261 		n = find_next_zero_bit(iommu->ctx_bitmap, lowest, 1);
262 		if (unlikely(n == lowest)) {
263 			printk(KERN_WARNING "IOMMU: Ran out of contexts.\n");
264 			n = 0;
265 		}
266 	}
267 	if (n)
268 		__set_bit(n, iommu->ctx_bitmap);
269 
270 	return n;
271 }
272 
273 static inline void iommu_free_ctx(struct iommu *iommu, int ctx)
274 {
275 	if (likely(ctx)) {
276 		__clear_bit(ctx, iommu->ctx_bitmap);
277 		if (ctx < iommu->ctx_lowest_free)
278 			iommu->ctx_lowest_free = ctx;
279 	}
280 }
281 
282 static void *dma_4u_alloc_coherent(struct device *dev, size_t size,
283 				   dma_addr_t *dma_addrp, gfp_t gfp)
284 {
285 	unsigned long flags, order, first_page;
286 	struct iommu *iommu;
287 	struct page *page;
288 	int npages, nid;
289 	iopte_t *iopte;
290 	void *ret;
291 
292 	size = IO_PAGE_ALIGN(size);
293 	order = get_order(size);
294 	if (order >= 10)
295 		return NULL;
296 
297 	nid = dev->archdata.numa_node;
298 	page = alloc_pages_node(nid, gfp, order);
299 	if (unlikely(!page))
300 		return NULL;
301 
302 	first_page = (unsigned long) page_address(page);
303 	memset((char *)first_page, 0, PAGE_SIZE << order);
304 
305 	iommu = dev->archdata.iommu;
306 
307 	spin_lock_irqsave(&iommu->lock, flags);
308 	iopte = alloc_npages(dev, iommu, size >> IO_PAGE_SHIFT);
309 	spin_unlock_irqrestore(&iommu->lock, flags);
310 
311 	if (unlikely(iopte == NULL)) {
312 		free_pages(first_page, order);
313 		return NULL;
314 	}
315 
316 	*dma_addrp = (iommu->page_table_map_base +
317 		      ((iopte - iommu->page_table) << IO_PAGE_SHIFT));
318 	ret = (void *) first_page;
319 	npages = size >> IO_PAGE_SHIFT;
320 	first_page = __pa(first_page);
321 	while (npages--) {
322 		iopte_val(*iopte) = (IOPTE_CONSISTENT(0UL) |
323 				     IOPTE_WRITE |
324 				     (first_page & IOPTE_PAGE));
325 		iopte++;
326 		first_page += IO_PAGE_SIZE;
327 	}
328 
329 	return ret;
330 }
331 
332 static void dma_4u_free_coherent(struct device *dev, size_t size,
333 				 void *cpu, dma_addr_t dvma)
334 {
335 	struct iommu *iommu;
336 	iopte_t *iopte;
337 	unsigned long flags, order, npages;
338 
339 	npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT;
340 	iommu = dev->archdata.iommu;
341 	iopte = iommu->page_table +
342 		((dvma - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
343 
344 	spin_lock_irqsave(&iommu->lock, flags);
345 
346 	iommu_range_free(iommu, dvma, npages);
347 
348 	spin_unlock_irqrestore(&iommu->lock, flags);
349 
350 	order = get_order(size);
351 	if (order < 10)
352 		free_pages((unsigned long)cpu, order);
353 }
354 
355 static dma_addr_t dma_4u_map_page(struct device *dev, struct page *page,
356 				  unsigned long offset, size_t sz,
357 				  enum dma_data_direction direction,
358 				  struct dma_attrs *attrs)
359 {
360 	struct iommu *iommu;
361 	struct strbuf *strbuf;
362 	iopte_t *base;
363 	unsigned long flags, npages, oaddr;
364 	unsigned long i, base_paddr, ctx;
365 	u32 bus_addr, ret;
366 	unsigned long iopte_protection;
367 
368 	iommu = dev->archdata.iommu;
369 	strbuf = dev->archdata.stc;
370 
371 	if (unlikely(direction == DMA_NONE))
372 		goto bad_no_ctx;
373 
374 	oaddr = (unsigned long)(page_address(page) + offset);
375 	npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK);
376 	npages >>= IO_PAGE_SHIFT;
377 
378 	spin_lock_irqsave(&iommu->lock, flags);
379 	base = alloc_npages(dev, iommu, npages);
380 	ctx = 0;
381 	if (iommu->iommu_ctxflush)
382 		ctx = iommu_alloc_ctx(iommu);
383 	spin_unlock_irqrestore(&iommu->lock, flags);
384 
385 	if (unlikely(!base))
386 		goto bad;
387 
388 	bus_addr = (iommu->page_table_map_base +
389 		    ((base - iommu->page_table) << IO_PAGE_SHIFT));
390 	ret = bus_addr | (oaddr & ~IO_PAGE_MASK);
391 	base_paddr = __pa(oaddr & IO_PAGE_MASK);
392 	if (strbuf->strbuf_enabled)
393 		iopte_protection = IOPTE_STREAMING(ctx);
394 	else
395 		iopte_protection = IOPTE_CONSISTENT(ctx);
396 	if (direction != DMA_TO_DEVICE)
397 		iopte_protection |= IOPTE_WRITE;
398 
399 	for (i = 0; i < npages; i++, base++, base_paddr += IO_PAGE_SIZE)
400 		iopte_val(*base) = iopte_protection | base_paddr;
401 
402 	return ret;
403 
404 bad:
405 	iommu_free_ctx(iommu, ctx);
406 bad_no_ctx:
407 	if (printk_ratelimit())
408 		WARN_ON(1);
409 	return DMA_ERROR_CODE;
410 }
411 
412 static void strbuf_flush(struct strbuf *strbuf, struct iommu *iommu,
413 			 u32 vaddr, unsigned long ctx, unsigned long npages,
414 			 enum dma_data_direction direction)
415 {
416 	int limit;
417 
418 	if (strbuf->strbuf_ctxflush &&
419 	    iommu->iommu_ctxflush) {
420 		unsigned long matchreg, flushreg;
421 		u64 val;
422 
423 		flushreg = strbuf->strbuf_ctxflush;
424 		matchreg = STC_CTXMATCH_ADDR(strbuf, ctx);
425 
426 		iommu_write(flushreg, ctx);
427 		val = iommu_read(matchreg);
428 		val &= 0xffff;
429 		if (!val)
430 			goto do_flush_sync;
431 
432 		while (val) {
433 			if (val & 0x1)
434 				iommu_write(flushreg, ctx);
435 			val >>= 1;
436 		}
437 		val = iommu_read(matchreg);
438 		if (unlikely(val)) {
439 			printk(KERN_WARNING "strbuf_flush: ctx flush "
440 			       "timeout matchreg[%llx] ctx[%lx]\n",
441 			       val, ctx);
442 			goto do_page_flush;
443 		}
444 	} else {
445 		unsigned long i;
446 
447 	do_page_flush:
448 		for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE)
449 			iommu_write(strbuf->strbuf_pflush, vaddr);
450 	}
451 
452 do_flush_sync:
453 	/* If the device could not have possibly put dirty data into
454 	 * the streaming cache, no flush-flag synchronization needs
455 	 * to be performed.
456 	 */
457 	if (direction == DMA_TO_DEVICE)
458 		return;
459 
460 	STC_FLUSHFLAG_INIT(strbuf);
461 	iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa);
462 	(void) iommu_read(iommu->write_complete_reg);
463 
464 	limit = 100000;
465 	while (!STC_FLUSHFLAG_SET(strbuf)) {
466 		limit--;
467 		if (!limit)
468 			break;
469 		udelay(1);
470 		rmb();
471 	}
472 	if (!limit)
473 		printk(KERN_WARNING "strbuf_flush: flushflag timeout "
474 		       "vaddr[%08x] ctx[%lx] npages[%ld]\n",
475 		       vaddr, ctx, npages);
476 }
477 
478 static void dma_4u_unmap_page(struct device *dev, dma_addr_t bus_addr,
479 			      size_t sz, enum dma_data_direction direction,
480 			      struct dma_attrs *attrs)
481 {
482 	struct iommu *iommu;
483 	struct strbuf *strbuf;
484 	iopte_t *base;
485 	unsigned long flags, npages, ctx, i;
486 
487 	if (unlikely(direction == DMA_NONE)) {
488 		if (printk_ratelimit())
489 			WARN_ON(1);
490 		return;
491 	}
492 
493 	iommu = dev->archdata.iommu;
494 	strbuf = dev->archdata.stc;
495 
496 	npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
497 	npages >>= IO_PAGE_SHIFT;
498 	base = iommu->page_table +
499 		((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
500 	bus_addr &= IO_PAGE_MASK;
501 
502 	spin_lock_irqsave(&iommu->lock, flags);
503 
504 	/* Record the context, if any. */
505 	ctx = 0;
506 	if (iommu->iommu_ctxflush)
507 		ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
508 
509 	/* Step 1: Kick data out of streaming buffers if necessary. */
510 	if (strbuf->strbuf_enabled)
511 		strbuf_flush(strbuf, iommu, bus_addr, ctx,
512 			     npages, direction);
513 
514 	/* Step 2: Clear out TSB entries. */
515 	for (i = 0; i < npages; i++)
516 		iopte_make_dummy(iommu, base + i);
517 
518 	iommu_range_free(iommu, bus_addr, npages);
519 
520 	iommu_free_ctx(iommu, ctx);
521 
522 	spin_unlock_irqrestore(&iommu->lock, flags);
523 }
524 
525 static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist,
526 			 int nelems, enum dma_data_direction direction,
527 			 struct dma_attrs *attrs)
528 {
529 	struct scatterlist *s, *outs, *segstart;
530 	unsigned long flags, handle, prot, ctx;
531 	dma_addr_t dma_next = 0, dma_addr;
532 	unsigned int max_seg_size;
533 	unsigned long seg_boundary_size;
534 	int outcount, incount, i;
535 	struct strbuf *strbuf;
536 	struct iommu *iommu;
537 	unsigned long base_shift;
538 
539 	BUG_ON(direction == DMA_NONE);
540 
541 	iommu = dev->archdata.iommu;
542 	strbuf = dev->archdata.stc;
543 	if (nelems == 0 || !iommu)
544 		return 0;
545 
546 	spin_lock_irqsave(&iommu->lock, flags);
547 
548 	ctx = 0;
549 	if (iommu->iommu_ctxflush)
550 		ctx = iommu_alloc_ctx(iommu);
551 
552 	if (strbuf->strbuf_enabled)
553 		prot = IOPTE_STREAMING(ctx);
554 	else
555 		prot = IOPTE_CONSISTENT(ctx);
556 	if (direction != DMA_TO_DEVICE)
557 		prot |= IOPTE_WRITE;
558 
559 	outs = s = segstart = &sglist[0];
560 	outcount = 1;
561 	incount = nelems;
562 	handle = 0;
563 
564 	/* Init first segment length for backout at failure */
565 	outs->dma_length = 0;
566 
567 	max_seg_size = dma_get_max_seg_size(dev);
568 	seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
569 				  IO_PAGE_SIZE) >> IO_PAGE_SHIFT;
570 	base_shift = iommu->page_table_map_base >> IO_PAGE_SHIFT;
571 	for_each_sg(sglist, s, nelems, i) {
572 		unsigned long paddr, npages, entry, out_entry = 0, slen;
573 		iopte_t *base;
574 
575 		slen = s->length;
576 		/* Sanity check */
577 		if (slen == 0) {
578 			dma_next = 0;
579 			continue;
580 		}
581 		/* Allocate iommu entries for that segment */
582 		paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s);
583 		npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE);
584 		entry = iommu_range_alloc(dev, iommu, npages, &handle);
585 
586 		/* Handle failure */
587 		if (unlikely(entry == DMA_ERROR_CODE)) {
588 			if (printk_ratelimit())
589 				printk(KERN_INFO "iommu_alloc failed, iommu %p paddr %lx"
590 				       " npages %lx\n", iommu, paddr, npages);
591 			goto iommu_map_failed;
592 		}
593 
594 		base = iommu->page_table + entry;
595 
596 		/* Convert entry to a dma_addr_t */
597 		dma_addr = iommu->page_table_map_base +
598 			(entry << IO_PAGE_SHIFT);
599 		dma_addr |= (s->offset & ~IO_PAGE_MASK);
600 
601 		/* Insert into HW table */
602 		paddr &= IO_PAGE_MASK;
603 		while (npages--) {
604 			iopte_val(*base) = prot | paddr;
605 			base++;
606 			paddr += IO_PAGE_SIZE;
607 		}
608 
609 		/* If we are in an open segment, try merging */
610 		if (segstart != s) {
611 			/* We cannot merge if:
612 			 * - allocated dma_addr isn't contiguous to previous allocation
613 			 */
614 			if ((dma_addr != dma_next) ||
615 			    (outs->dma_length + s->length > max_seg_size) ||
616 			    (is_span_boundary(out_entry, base_shift,
617 					      seg_boundary_size, outs, s))) {
618 				/* Can't merge: create a new segment */
619 				segstart = s;
620 				outcount++;
621 				outs = sg_next(outs);
622 			} else {
623 				outs->dma_length += s->length;
624 			}
625 		}
626 
627 		if (segstart == s) {
628 			/* This is a new segment, fill entries */
629 			outs->dma_address = dma_addr;
630 			outs->dma_length = slen;
631 			out_entry = entry;
632 		}
633 
634 		/* Calculate next page pointer for contiguous check */
635 		dma_next = dma_addr + slen;
636 	}
637 
638 	spin_unlock_irqrestore(&iommu->lock, flags);
639 
640 	if (outcount < incount) {
641 		outs = sg_next(outs);
642 		outs->dma_address = DMA_ERROR_CODE;
643 		outs->dma_length = 0;
644 	}
645 
646 	return outcount;
647 
648 iommu_map_failed:
649 	for_each_sg(sglist, s, nelems, i) {
650 		if (s->dma_length != 0) {
651 			unsigned long vaddr, npages, entry, j;
652 			iopte_t *base;
653 
654 			vaddr = s->dma_address & IO_PAGE_MASK;
655 			npages = iommu_num_pages(s->dma_address, s->dma_length,
656 						 IO_PAGE_SIZE);
657 			iommu_range_free(iommu, vaddr, npages);
658 
659 			entry = (vaddr - iommu->page_table_map_base)
660 				>> IO_PAGE_SHIFT;
661 			base = iommu->page_table + entry;
662 
663 			for (j = 0; j < npages; j++)
664 				iopte_make_dummy(iommu, base + j);
665 
666 			s->dma_address = DMA_ERROR_CODE;
667 			s->dma_length = 0;
668 		}
669 		if (s == outs)
670 			break;
671 	}
672 	spin_unlock_irqrestore(&iommu->lock, flags);
673 
674 	return 0;
675 }
676 
677 /* If contexts are being used, they are the same in all of the mappings
678  * we make for a particular SG.
679  */
680 static unsigned long fetch_sg_ctx(struct iommu *iommu, struct scatterlist *sg)
681 {
682 	unsigned long ctx = 0;
683 
684 	if (iommu->iommu_ctxflush) {
685 		iopte_t *base;
686 		u32 bus_addr;
687 
688 		bus_addr = sg->dma_address & IO_PAGE_MASK;
689 		base = iommu->page_table +
690 			((bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
691 
692 		ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL;
693 	}
694 	return ctx;
695 }
696 
697 static void dma_4u_unmap_sg(struct device *dev, struct scatterlist *sglist,
698 			    int nelems, enum dma_data_direction direction,
699 			    struct dma_attrs *attrs)
700 {
701 	unsigned long flags, ctx;
702 	struct scatterlist *sg;
703 	struct strbuf *strbuf;
704 	struct iommu *iommu;
705 
706 	BUG_ON(direction == DMA_NONE);
707 
708 	iommu = dev->archdata.iommu;
709 	strbuf = dev->archdata.stc;
710 
711 	ctx = fetch_sg_ctx(iommu, sglist);
712 
713 	spin_lock_irqsave(&iommu->lock, flags);
714 
715 	sg = sglist;
716 	while (nelems--) {
717 		dma_addr_t dma_handle = sg->dma_address;
718 		unsigned int len = sg->dma_length;
719 		unsigned long npages, entry;
720 		iopte_t *base;
721 		int i;
722 
723 		if (!len)
724 			break;
725 		npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE);
726 		iommu_range_free(iommu, dma_handle, npages);
727 
728 		entry = ((dma_handle - iommu->page_table_map_base)
729 			 >> IO_PAGE_SHIFT);
730 		base = iommu->page_table + entry;
731 
732 		dma_handle &= IO_PAGE_MASK;
733 		if (strbuf->strbuf_enabled)
734 			strbuf_flush(strbuf, iommu, dma_handle, ctx,
735 				     npages, direction);
736 
737 		for (i = 0; i < npages; i++)
738 			iopte_make_dummy(iommu, base + i);
739 
740 		sg = sg_next(sg);
741 	}
742 
743 	iommu_free_ctx(iommu, ctx);
744 
745 	spin_unlock_irqrestore(&iommu->lock, flags);
746 }
747 
748 static void dma_4u_sync_single_for_cpu(struct device *dev,
749 				       dma_addr_t bus_addr, size_t sz,
750 				       enum dma_data_direction direction)
751 {
752 	struct iommu *iommu;
753 	struct strbuf *strbuf;
754 	unsigned long flags, ctx, npages;
755 
756 	iommu = dev->archdata.iommu;
757 	strbuf = dev->archdata.stc;
758 
759 	if (!strbuf->strbuf_enabled)
760 		return;
761 
762 	spin_lock_irqsave(&iommu->lock, flags);
763 
764 	npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK);
765 	npages >>= IO_PAGE_SHIFT;
766 	bus_addr &= IO_PAGE_MASK;
767 
768 	/* Step 1: Record the context, if any. */
769 	ctx = 0;
770 	if (iommu->iommu_ctxflush &&
771 	    strbuf->strbuf_ctxflush) {
772 		iopte_t *iopte;
773 
774 		iopte = iommu->page_table +
775 			((bus_addr - iommu->page_table_map_base)>>IO_PAGE_SHIFT);
776 		ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
777 	}
778 
779 	/* Step 2: Kick data out of streaming buffers. */
780 	strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
781 
782 	spin_unlock_irqrestore(&iommu->lock, flags);
783 }
784 
785 static void dma_4u_sync_sg_for_cpu(struct device *dev,
786 				   struct scatterlist *sglist, int nelems,
787 				   enum dma_data_direction direction)
788 {
789 	struct iommu *iommu;
790 	struct strbuf *strbuf;
791 	unsigned long flags, ctx, npages, i;
792 	struct scatterlist *sg, *sgprv;
793 	u32 bus_addr;
794 
795 	iommu = dev->archdata.iommu;
796 	strbuf = dev->archdata.stc;
797 
798 	if (!strbuf->strbuf_enabled)
799 		return;
800 
801 	spin_lock_irqsave(&iommu->lock, flags);
802 
803 	/* Step 1: Record the context, if any. */
804 	ctx = 0;
805 	if (iommu->iommu_ctxflush &&
806 	    strbuf->strbuf_ctxflush) {
807 		iopte_t *iopte;
808 
809 		iopte = iommu->page_table +
810 			((sglist[0].dma_address - iommu->page_table_map_base) >> IO_PAGE_SHIFT);
811 		ctx = (iopte_val(*iopte) & IOPTE_CONTEXT) >> 47UL;
812 	}
813 
814 	/* Step 2: Kick data out of streaming buffers. */
815 	bus_addr = sglist[0].dma_address & IO_PAGE_MASK;
816 	sgprv = NULL;
817 	for_each_sg(sglist, sg, nelems, i) {
818 		if (sg->dma_length == 0)
819 			break;
820 		sgprv = sg;
821 	}
822 
823 	npages = (IO_PAGE_ALIGN(sgprv->dma_address + sgprv->dma_length)
824 		  - bus_addr) >> IO_PAGE_SHIFT;
825 	strbuf_flush(strbuf, iommu, bus_addr, ctx, npages, direction);
826 
827 	spin_unlock_irqrestore(&iommu->lock, flags);
828 }
829 
830 static struct dma_map_ops sun4u_dma_ops = {
831 	.alloc_coherent		= dma_4u_alloc_coherent,
832 	.free_coherent		= dma_4u_free_coherent,
833 	.map_page		= dma_4u_map_page,
834 	.unmap_page		= dma_4u_unmap_page,
835 	.map_sg			= dma_4u_map_sg,
836 	.unmap_sg		= dma_4u_unmap_sg,
837 	.sync_single_for_cpu	= dma_4u_sync_single_for_cpu,
838 	.sync_sg_for_cpu	= dma_4u_sync_sg_for_cpu,
839 };
840 
841 struct dma_map_ops *dma_ops = &sun4u_dma_ops;
842 EXPORT_SYMBOL(dma_ops);
843 
844 extern int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask);
845 
846 int dma_supported(struct device *dev, u64 device_mask)
847 {
848 	struct iommu *iommu = dev->archdata.iommu;
849 	u64 dma_addr_mask = iommu->dma_addr_mask;
850 
851 	if (device_mask >= (1UL << 32UL))
852 		return 0;
853 
854 	if ((device_mask & dma_addr_mask) == dma_addr_mask)
855 		return 1;
856 
857 #ifdef CONFIG_PCI
858 	if (dev->bus == &pci_bus_type)
859 		return pci64_dma_supported(to_pci_dev(dev), device_mask);
860 #endif
861 
862 	return 0;
863 }
864 EXPORT_SYMBOL(dma_supported);
865 
866 int dma_set_mask(struct device *dev, u64 dma_mask)
867 {
868 #ifdef CONFIG_PCI
869 	if (dev->bus == &pci_bus_type)
870 		return pci_set_dma_mask(to_pci_dev(dev), dma_mask);
871 #endif
872 	return -EINVAL;
873 }
874 EXPORT_SYMBOL(dma_set_mask);
875