2 * Dynamic DMA mapping support.
4 * This implementation is a fallback for platforms that do not support
5 * I/O TLBs (aka DMA address translation hardware).
6 * Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
7 * Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
8 * Copyright (C) 2000, 2003 Hewlett-Packard Co
9 * David Mosberger-Tang <davidm@hpl.hp.com>
11 * 03/05/07 davidm Switch from PCI-DMA to generic device DMA API.
12 * 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid
13 * unnecessary i-cache flushing.
14 * 04/07/.. ak Better overflow handling. Assorted fixes.
15 * 05/09/10 linville Add support for syncing ranges, support syncing for
16 * DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
17 * 08/12/11 beckyb Add highmem support
20 #include <linux/cache.h>
21 #include <linux/dma-mapping.h>
23 #include <linux/module.h>
24 #include <linux/spinlock.h>
25 #include <linux/string.h>
26 #include <linux/swiotlb.h>
27 #include <linux/pfn.h>
28 #include <linux/types.h>
29 #include <linux/ctype.h>
30 #include <linux/highmem.h>
31 #include <linux/gfp.h>
35 #include <asm/scatterlist.h>
37 #include <linux/init.h>
38 #include <linux/bootmem.h>
39 #include <linux/iommu-helper.h>
41 #define OFFSET(val,align) ((unsigned long) \
42 ( (val) & ( (align) - 1)))
44 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
47 * Minimum IO TLB size to bother booting with. Systems with mainly
48 * 64bit capable cards will only lightly use the swiotlb. If we can't
49 * allocate a contiguous 1MB, we're probably in trouble anyway.
51 #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
56 * Used to do a quick range check in swiotlb_tbl_unmap_single and
57 * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
60 static char *io_tlb_start, *io_tlb_end;
63 * The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
64 * io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
66 static unsigned long io_tlb_nslabs;
69 * When the IOMMU overflows we return a fallback buffer. This sets the size.
71 static unsigned long io_tlb_overflow = 32*1024;
73 void *io_tlb_overflow_buffer;
76 * This is a free list describing the number of free entries available from
79 static unsigned int *io_tlb_list;
80 static unsigned int io_tlb_index;
83 * We need to save away the original address corresponding to a mapped entry
84 * for the sync operations.
86 static phys_addr_t *io_tlb_orig_addr;
89 * Protect the above data structures in the map and unmap calls
91 static DEFINE_SPINLOCK(io_tlb_lock);
93 static int late_alloc;
96 setup_io_tlb_npages(char *str)
99 io_tlb_nslabs = simple_strtoul(str, &str, 0);
100 /* avoid tail segment of size < IO_TLB_SEGSIZE */
101 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
105 if (!strcmp(str, "force"))
110 __setup("swiotlb=", setup_io_tlb_npages);
111 /* make io_tlb_overflow tunable too? */
113 /* Note that this doesn't work with highmem page */
114 static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
115 volatile void *address)
117 return phys_to_dma(hwdev, virt_to_phys(address));
120 void swiotlb_print_info(void)
122 unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
123 phys_addr_t pstart, pend;
125 pstart = virt_to_phys(io_tlb_start);
126 pend = virt_to_phys(io_tlb_end);
128 printk(KERN_INFO "Placing %luMB software IO TLB between %p - %p\n",
129 bytes >> 20, io_tlb_start, io_tlb_end);
130 printk(KERN_INFO "software IO TLB at phys %#llx - %#llx\n",
131 (unsigned long long)pstart,
132 (unsigned long long)pend);
135 void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
137 unsigned long i, bytes;
139 bytes = nslabs << IO_TLB_SHIFT;
141 io_tlb_nslabs = nslabs;
143 io_tlb_end = io_tlb_start + bytes;
146 * Allocate and initialize the free list array. This array is used
147 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
148 * between io_tlb_start and io_tlb_end.
150 io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
151 for (i = 0; i < io_tlb_nslabs; i++)
152 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
154 io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));
157 * Get the overflow emergency buffer
159 io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
160 if (!io_tlb_overflow_buffer)
161 panic("Cannot allocate SWIOTLB overflow buffer!\n");
163 swiotlb_print_info();
167 * Statically reserve bounce buffer space and initialize bounce buffer data
168 * structures for the software IO TLB used to implement the DMA API.
171 swiotlb_init_with_default_size(size_t default_size, int verbose)
175 if (!io_tlb_nslabs) {
176 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
177 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
180 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
183 * Get IO TLB memory from the low pages
185 io_tlb_start = alloc_bootmem_low_pages(bytes);
187 panic("Cannot allocate SWIOTLB buffer");
189 swiotlb_init_with_tbl(io_tlb_start, io_tlb_nslabs, verbose);
193 swiotlb_init(int verbose)
195 swiotlb_init_with_default_size(64 * (1<<20), verbose); /* default to 64MB */
199 * Systems with larger DMA zones (those that don't support ISA) can
200 * initialize the swiotlb later using the slab allocator if needed.
201 * This should be just like above, but with some error catching.
204 swiotlb_late_init_with_default_size(size_t default_size)
206 unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
209 if (!io_tlb_nslabs) {
210 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
211 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
215 * Get IO TLB memory from the low pages
217 order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
218 io_tlb_nslabs = SLABS_PER_PAGE << order;
219 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
221 while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
222 io_tlb_start = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
232 if (order != get_order(bytes)) {
233 printk(KERN_WARNING "Warning: only able to allocate %ld MB "
234 "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
235 io_tlb_nslabs = SLABS_PER_PAGE << order;
236 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
238 io_tlb_end = io_tlb_start + bytes;
239 memset(io_tlb_start, 0, bytes);
242 * Allocate and initialize the free list array. This array is used
243 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
244 * between io_tlb_start and io_tlb_end.
246 io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
247 get_order(io_tlb_nslabs * sizeof(int)));
251 for (i = 0; i < io_tlb_nslabs; i++)
252 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
255 io_tlb_orig_addr = (phys_addr_t *)
256 __get_free_pages(GFP_KERNEL,
257 get_order(io_tlb_nslabs *
258 sizeof(phys_addr_t)));
259 if (!io_tlb_orig_addr)
262 memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
265 * Get the overflow emergency buffer
267 io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
268 get_order(io_tlb_overflow));
269 if (!io_tlb_overflow_buffer)
272 swiotlb_print_info();
279 free_pages((unsigned long)io_tlb_orig_addr,
280 get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
281 io_tlb_orig_addr = NULL;
283 free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
288 free_pages((unsigned long)io_tlb_start, order);
291 io_tlb_nslabs = req_nslabs;
295 void __init swiotlb_free(void)
297 if (!io_tlb_overflow_buffer)
301 free_pages((unsigned long)io_tlb_overflow_buffer,
302 get_order(io_tlb_overflow));
303 free_pages((unsigned long)io_tlb_orig_addr,
304 get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
305 free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
307 free_pages((unsigned long)io_tlb_start,
308 get_order(io_tlb_nslabs << IO_TLB_SHIFT));
310 free_bootmem_late(__pa(io_tlb_overflow_buffer),
312 free_bootmem_late(__pa(io_tlb_orig_addr),
313 io_tlb_nslabs * sizeof(phys_addr_t));
314 free_bootmem_late(__pa(io_tlb_list),
315 io_tlb_nslabs * sizeof(int));
316 free_bootmem_late(__pa(io_tlb_start),
317 io_tlb_nslabs << IO_TLB_SHIFT);
321 static int is_swiotlb_buffer(phys_addr_t paddr)
323 return paddr >= virt_to_phys(io_tlb_start) &&
324 paddr < virt_to_phys(io_tlb_end);
328 * Bounce: copy the swiotlb buffer back to the original dma location
330 void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
331 enum dma_data_direction dir)
333 unsigned long pfn = PFN_DOWN(phys);
335 if (PageHighMem(pfn_to_page(pfn))) {
336 /* The buffer does not have a mapping. Map it in and copy */
337 unsigned int offset = phys & ~PAGE_MASK;
343 sz = min_t(size_t, PAGE_SIZE - offset, size);
345 local_irq_save(flags);
346 buffer = kmap_atomic(pfn_to_page(pfn),
348 if (dir == DMA_TO_DEVICE)
349 memcpy(dma_addr, buffer + offset, sz);
351 memcpy(buffer + offset, dma_addr, sz);
352 kunmap_atomic(buffer, KM_BOUNCE_READ);
353 local_irq_restore(flags);
361 if (dir == DMA_TO_DEVICE)
362 memcpy(dma_addr, phys_to_virt(phys), size);
364 memcpy(phys_to_virt(phys), dma_addr, size);
367 EXPORT_SYMBOL_GPL(swiotlb_bounce);
369 void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
370 phys_addr_t phys, size_t size,
371 enum dma_data_direction dir)
375 unsigned int nslots, stride, index, wrap;
378 unsigned long offset_slots;
379 unsigned long max_slots;
381 mask = dma_get_seg_boundary(hwdev);
383 tbl_dma_addr &= mask;
385 offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
388 * Carefully handle integer overflow which can occur when mask == ~0UL.
391 ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
392 : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
395 * For mappings greater than a page, we limit the stride (and
396 * hence alignment) to a page size.
398 nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
399 if (size > PAGE_SIZE)
400 stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
407 * Find suitable number of IO TLB entries size that will fit this
408 * request and allocate a buffer from that IO TLB pool.
410 spin_lock_irqsave(&io_tlb_lock, flags);
411 index = ALIGN(io_tlb_index, stride);
412 if (index >= io_tlb_nslabs)
417 while (iommu_is_span_boundary(index, nslots, offset_slots,
420 if (index >= io_tlb_nslabs)
427 * If we find a slot that indicates we have 'nslots' number of
428 * contiguous buffers, we allocate the buffers from that slot
429 * and mark the entries as '0' indicating unavailable.
431 if (io_tlb_list[index] >= nslots) {
434 for (i = index; i < (int) (index + nslots); i++)
436 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
437 io_tlb_list[i] = ++count;
438 dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
441 * Update the indices to avoid searching in the next
444 io_tlb_index = ((index + nslots) < io_tlb_nslabs
445 ? (index + nslots) : 0);
450 if (index >= io_tlb_nslabs)
452 } while (index != wrap);
455 spin_unlock_irqrestore(&io_tlb_lock, flags);
458 spin_unlock_irqrestore(&io_tlb_lock, flags);
461 * Save away the mapping from the original address to the DMA address.
462 * This is needed when we sync the memory. Then we sync the buffer if
465 for (i = 0; i < nslots; i++)
466 io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT);
467 if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
468 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
472 EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single);
475 * Allocates bounce buffer and returns its kernel virtual address.
479 map_single(struct device *hwdev, phys_addr_t phys, size_t size,
480 enum dma_data_direction dir)
482 dma_addr_t start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start);
484 return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir);
488 * dma_addr is the kernel virtual address of the bounce buffer to unmap.
491 swiotlb_tbl_unmap_single(struct device *hwdev, char *dma_addr, size_t size,
492 enum dma_data_direction dir)
495 int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
496 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
497 phys_addr_t phys = io_tlb_orig_addr[index];
500 * First, sync the memory before unmapping the entry
502 if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
503 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
506 * Return the buffer to the free list by setting the corresponding
507 * entries to indicate the number of contiguous entries available.
508 * While returning the entries to the free list, we merge the entries
509 * with slots below and above the pool being returned.
511 spin_lock_irqsave(&io_tlb_lock, flags);
513 count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
514 io_tlb_list[index + nslots] : 0);
516 * Step 1: return the slots to the free list, merging the
517 * slots with superceeding slots
519 for (i = index + nslots - 1; i >= index; i--)
520 io_tlb_list[i] = ++count;
522 * Step 2: merge the returned slots with the preceding slots,
523 * if available (non zero)
525 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
526 io_tlb_list[i] = ++count;
528 spin_unlock_irqrestore(&io_tlb_lock, flags);
530 EXPORT_SYMBOL_GPL(swiotlb_tbl_unmap_single);
533 swiotlb_tbl_sync_single(struct device *hwdev, char *dma_addr, size_t size,
534 enum dma_data_direction dir,
535 enum dma_sync_target target)
537 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
538 phys_addr_t phys = io_tlb_orig_addr[index];
540 phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
544 if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
545 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
547 BUG_ON(dir != DMA_TO_DEVICE);
549 case SYNC_FOR_DEVICE:
550 if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
551 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
553 BUG_ON(dir != DMA_FROM_DEVICE);
559 EXPORT_SYMBOL_GPL(swiotlb_tbl_sync_single);
562 swiotlb_alloc_coherent(struct device *hwdev, size_t size,
563 dma_addr_t *dma_handle, gfp_t flags)
567 int order = get_order(size);
568 u64 dma_mask = DMA_BIT_MASK(32);
570 if (hwdev && hwdev->coherent_dma_mask)
571 dma_mask = hwdev->coherent_dma_mask;
573 ret = (void *)__get_free_pages(flags, order);
574 if (ret && swiotlb_virt_to_bus(hwdev, ret) + size - 1 > dma_mask) {
576 * The allocated memory isn't reachable by the device.
578 free_pages((unsigned long) ret, order);
583 * We are either out of memory or the device can't DMA to
584 * GFP_DMA memory; fall back on map_single(), which
585 * will grab memory from the lowest available address range.
587 ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
592 memset(ret, 0, size);
593 dev_addr = swiotlb_virt_to_bus(hwdev, ret);
595 /* Confirm address can be DMA'd by device */
596 if (dev_addr + size - 1 > dma_mask) {
597 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
598 (unsigned long long)dma_mask,
599 (unsigned long long)dev_addr);
601 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
602 swiotlb_tbl_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
605 *dma_handle = dev_addr;
608 EXPORT_SYMBOL(swiotlb_alloc_coherent);
611 swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
614 phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
616 WARN_ON(irqs_disabled());
617 if (!is_swiotlb_buffer(paddr))
618 free_pages((unsigned long)vaddr, get_order(size));
620 /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */
621 swiotlb_tbl_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
623 EXPORT_SYMBOL(swiotlb_free_coherent);
626 swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir,
630 * Ran out of IOMMU space for this operation. This is very bad.
631 * Unfortunately the drivers cannot handle this operation properly.
632 * unless they check for dma_mapping_error (most don't)
633 * When the mapping is small enough return a static buffer to limit
634 * the damage, or panic when the transfer is too big.
636 printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
637 "device %s\n", size, dev ? dev_name(dev) : "?");
639 if (size <= io_tlb_overflow || !do_panic)
642 if (dir == DMA_BIDIRECTIONAL)
643 panic("DMA: Random memory could be DMA accessed\n");
644 if (dir == DMA_FROM_DEVICE)
645 panic("DMA: Random memory could be DMA written\n");
646 if (dir == DMA_TO_DEVICE)
647 panic("DMA: Random memory could be DMA read\n");
651 * Map a single buffer of the indicated size for DMA in streaming mode. The
652 * physical address to use is returned.
654 * Once the device is given the dma address, the device owns this memory until
655 * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed.
657 dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
658 unsigned long offset, size_t size,
659 enum dma_data_direction dir,
660 struct dma_attrs *attrs)
662 phys_addr_t phys = page_to_phys(page) + offset;
663 dma_addr_t dev_addr = phys_to_dma(dev, phys);
666 BUG_ON(dir == DMA_NONE);
668 * If the address happens to be in the device's DMA window,
669 * we can safely return the device addr and not worry about bounce
672 if (dma_capable(dev, dev_addr, size) && !swiotlb_force)
676 * Oh well, have to allocate and map a bounce buffer.
678 map = map_single(dev, phys, size, dir);
680 swiotlb_full(dev, size, dir, 1);
681 map = io_tlb_overflow_buffer;
684 dev_addr = swiotlb_virt_to_bus(dev, map);
687 * Ensure that the address returned is DMA'ble
689 if (!dma_capable(dev, dev_addr, size))
690 panic("map_single: bounce buffer is not DMA'ble");
694 EXPORT_SYMBOL_GPL(swiotlb_map_page);
697 * Unmap a single streaming mode DMA translation. The dma_addr and size must
698 * match what was provided for in a previous swiotlb_map_page call. All
699 * other usages are undefined.
701 * After this call, reads by the cpu to the buffer are guaranteed to see
702 * whatever the device wrote there.
704 static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
705 size_t size, enum dma_data_direction dir)
707 phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
709 BUG_ON(dir == DMA_NONE);
711 if (is_swiotlb_buffer(paddr)) {
712 swiotlb_tbl_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
716 if (dir != DMA_FROM_DEVICE)
720 * phys_to_virt doesn't work with hihgmem page but we could
721 * call dma_mark_clean() with hihgmem page here. However, we
722 * are fine since dma_mark_clean() is null on POWERPC. We can
723 * make dma_mark_clean() take a physical address if necessary.
725 dma_mark_clean(phys_to_virt(paddr), size);
728 void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
729 size_t size, enum dma_data_direction dir,
730 struct dma_attrs *attrs)
732 unmap_single(hwdev, dev_addr, size, dir);
734 EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
737 * Make physical memory consistent for a single streaming mode DMA translation
740 * If you perform a swiotlb_map_page() but wish to interrogate the buffer
741 * using the cpu, yet do not wish to teardown the dma mapping, you must
742 * call this function before doing so. At the next point you give the dma
743 * address back to the card, you must first perform a
744 * swiotlb_dma_sync_for_device, and then the device again owns the buffer
747 swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
748 size_t size, enum dma_data_direction dir,
749 enum dma_sync_target target)
751 phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
753 BUG_ON(dir == DMA_NONE);
755 if (is_swiotlb_buffer(paddr)) {
756 swiotlb_tbl_sync_single(hwdev, phys_to_virt(paddr), size, dir,
761 if (dir != DMA_FROM_DEVICE)
764 dma_mark_clean(phys_to_virt(paddr), size);
768 swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
769 size_t size, enum dma_data_direction dir)
771 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
773 EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
776 swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
777 size_t size, enum dma_data_direction dir)
779 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
781 EXPORT_SYMBOL(swiotlb_sync_single_for_device);
784 * Map a set of buffers described by scatterlist in streaming mode for DMA.
785 * This is the scatter-gather version of the above swiotlb_map_page
786 * interface. Here the scatter gather list elements are each tagged with the
787 * appropriate dma address and length. They are obtained via
788 * sg_dma_{address,length}(SG).
790 * NOTE: An implementation may be able to use a smaller number of
791 * DMA address/length pairs than there are SG table elements.
792 * (for example via virtual mapping capabilities)
793 * The routine returns the number of addr/length pairs actually
794 * used, at most nents.
796 * Device ownership issues as mentioned above for swiotlb_map_page are the
800 swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
801 enum dma_data_direction dir, struct dma_attrs *attrs)
803 struct scatterlist *sg;
806 BUG_ON(dir == DMA_NONE);
808 for_each_sg(sgl, sg, nelems, i) {
809 phys_addr_t paddr = sg_phys(sg);
810 dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
813 !dma_capable(hwdev, dev_addr, sg->length)) {
814 void *map = map_single(hwdev, sg_phys(sg),
817 /* Don't panic here, we expect map_sg users
818 to do proper error handling. */
819 swiotlb_full(hwdev, sg->length, dir, 0);
820 swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
822 sgl[0].dma_length = 0;
825 sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
827 sg->dma_address = dev_addr;
828 sg->dma_length = sg->length;
832 EXPORT_SYMBOL(swiotlb_map_sg_attrs);
835 swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
836 enum dma_data_direction dir)
838 return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
840 EXPORT_SYMBOL(swiotlb_map_sg);
843 * Unmap a set of streaming mode DMA translations. Again, cpu read rules
844 * concerning calls here are the same as for swiotlb_unmap_page() above.
847 swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
848 int nelems, enum dma_data_direction dir, struct dma_attrs *attrs)
850 struct scatterlist *sg;
853 BUG_ON(dir == DMA_NONE);
855 for_each_sg(sgl, sg, nelems, i)
856 unmap_single(hwdev, sg->dma_address, sg->dma_length, dir);
859 EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
862 swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
863 enum dma_data_direction dir)
865 return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
867 EXPORT_SYMBOL(swiotlb_unmap_sg);
870 * Make physical memory consistent for a set of streaming mode DMA translations
873 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
877 swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
878 int nelems, enum dma_data_direction dir,
879 enum dma_sync_target target)
881 struct scatterlist *sg;
884 for_each_sg(sgl, sg, nelems, i)
885 swiotlb_sync_single(hwdev, sg->dma_address,
886 sg->dma_length, dir, target);
890 swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
891 int nelems, enum dma_data_direction dir)
893 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
895 EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
898 swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
899 int nelems, enum dma_data_direction dir)
901 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
903 EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
906 swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
908 return (dma_addr == swiotlb_virt_to_bus(hwdev, io_tlb_overflow_buffer));
910 EXPORT_SYMBOL(swiotlb_dma_mapping_error);
913 * Return whether the given device DMA address mask can be supported
914 * properly. For example, if your device can only drive the low 24-bits
915 * during bus mastering, then you would pass 0x00ffffff as the mask to
919 swiotlb_dma_supported(struct device *hwdev, u64 mask)
921 return swiotlb_virt_to_bus(hwdev, io_tlb_end - 1) <= mask;
923 EXPORT_SYMBOL(swiotlb_dma_supported);