2 * Dynamic DMA mapping support.
4 * This implementation is for IA-64 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.
17 #include <linux/cache.h>
19 #include <linux/module.h>
20 #include <linux/pci.h>
21 #include <linux/spinlock.h>
22 #include <linux/string.h>
23 #include <linux/types.h>
24 #include <linux/ctype.h>
30 #include <linux/init.h>
31 #include <linux/bootmem.h>
33 #define OFFSET(val,align) ((unsigned long) \
34 ( (val) & ( (align) - 1)))
36 #define SG_ENT_VIRT_ADDRESS(sg) (page_address((sg)->page) + (sg)->offset)
37 #define SG_ENT_PHYS_ADDRESS(SG) virt_to_phys(SG_ENT_VIRT_ADDRESS(SG))
40 * Maximum allowable number of contiguous slabs to map,
41 * must be a power of 2. What is the appropriate value ?
42 * The complexity of {map,unmap}_single is linearly dependent on this value.
44 #define IO_TLB_SEGSIZE 128
47 * log of the size of each IO TLB slab. The number of slabs is command line
50 #define IO_TLB_SHIFT 11
52 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
55 * Minimum IO TLB size to bother booting with. Systems with mainly
56 * 64bit capable cards will only lightly use the swiotlb. If we can't
57 * allocate a contiguous 1MB, we're probably in trouble anyway.
59 #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
64 * Used to do a quick range check in swiotlb_unmap_single and
65 * swiotlb_sync_single_*, to see if the memory was in fact allocated by this
68 static char *io_tlb_start
, *io_tlb_end
;
71 * The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
72 * io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
74 static unsigned long io_tlb_nslabs
;
77 * When the IOMMU overflows we return a fallback buffer. This sets the size.
79 static unsigned long io_tlb_overflow
= 32*1024;
81 void *io_tlb_overflow_buffer
;
84 * This is a free list describing the number of free entries available from
87 static unsigned int *io_tlb_list
;
88 static unsigned int io_tlb_index
;
91 * We need to save away the original address corresponding to a mapped entry
92 * for the sync operations.
94 static unsigned char **io_tlb_orig_addr
;
97 * Protect the above data structures in the map and unmap calls
99 static DEFINE_SPINLOCK(io_tlb_lock
);
102 setup_io_tlb_npages(char *str
)
105 io_tlb_nslabs
= simple_strtoul(str
, &str
, 0);
106 /* avoid tail segment of size < IO_TLB_SEGSIZE */
107 io_tlb_nslabs
= ALIGN(io_tlb_nslabs
, IO_TLB_SEGSIZE
);
111 if (!strcmp(str
, "force"))
115 __setup("swiotlb=", setup_io_tlb_npages
);
116 /* make io_tlb_overflow tunable too? */
119 * Statically reserve bounce buffer space and initialize bounce buffer data
120 * structures for the software IO TLB used to implement the PCI DMA API.
123 swiotlb_init_with_default_size (size_t default_size
)
127 if (!io_tlb_nslabs
) {
128 io_tlb_nslabs
= (default_size
>> IO_TLB_SHIFT
);
129 io_tlb_nslabs
= ALIGN(io_tlb_nslabs
, IO_TLB_SEGSIZE
);
133 * Get IO TLB memory from the low pages
135 io_tlb_start
= alloc_bootmem_low_pages(io_tlb_nslabs
*
136 (1 << IO_TLB_SHIFT
));
138 panic("Cannot allocate SWIOTLB buffer");
139 io_tlb_end
= io_tlb_start
+ io_tlb_nslabs
* (1 << IO_TLB_SHIFT
);
142 * Allocate and initialize the free list array. This array is used
143 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
144 * between io_tlb_start and io_tlb_end.
146 io_tlb_list
= alloc_bootmem(io_tlb_nslabs
* sizeof(int));
147 for (i
= 0; i
< io_tlb_nslabs
; i
++)
148 io_tlb_list
[i
] = IO_TLB_SEGSIZE
- OFFSET(i
, IO_TLB_SEGSIZE
);
150 io_tlb_orig_addr
= alloc_bootmem(io_tlb_nslabs
* sizeof(char *));
153 * Get the overflow emergency buffer
155 io_tlb_overflow_buffer
= alloc_bootmem_low(io_tlb_overflow
);
156 printk(KERN_INFO
"Placing software IO TLB between 0x%lx - 0x%lx\n",
157 virt_to_phys(io_tlb_start
), virt_to_phys(io_tlb_end
));
163 swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
167 * Systems with larger DMA zones (those that don't support ISA) can
168 * initialize the swiotlb later using the slab allocator if needed.
169 * This should be just like above, but with some error catching.
172 swiotlb_late_init_with_default_size (size_t default_size
)
174 unsigned long i
, req_nslabs
= io_tlb_nslabs
;
177 if (!io_tlb_nslabs
) {
178 io_tlb_nslabs
= (default_size
>> IO_TLB_SHIFT
);
179 io_tlb_nslabs
= ALIGN(io_tlb_nslabs
, IO_TLB_SEGSIZE
);
183 * Get IO TLB memory from the low pages
185 order
= get_order(io_tlb_nslabs
* (1 << IO_TLB_SHIFT
));
186 io_tlb_nslabs
= SLABS_PER_PAGE
<< order
;
188 while ((SLABS_PER_PAGE
<< order
) > IO_TLB_MIN_SLABS
) {
189 io_tlb_start
= (char *)__get_free_pages(GFP_DMA
| __GFP_NOWARN
,
199 if (order
!= get_order(io_tlb_nslabs
* (1 << IO_TLB_SHIFT
))) {
200 printk(KERN_WARNING
"Warning: only able to allocate %ld MB "
201 "for software IO TLB\n", (PAGE_SIZE
<< order
) >> 20);
202 io_tlb_nslabs
= SLABS_PER_PAGE
<< order
;
204 io_tlb_end
= io_tlb_start
+ io_tlb_nslabs
* (1 << IO_TLB_SHIFT
);
205 memset(io_tlb_start
, 0, io_tlb_nslabs
* (1 << IO_TLB_SHIFT
));
208 * Allocate and initialize the free list array. This array is used
209 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
210 * between io_tlb_start and io_tlb_end.
212 io_tlb_list
= (unsigned int *)__get_free_pages(GFP_KERNEL
,
213 get_order(io_tlb_nslabs
* sizeof(int)));
217 for (i
= 0; i
< io_tlb_nslabs
; i
++)
218 io_tlb_list
[i
] = IO_TLB_SEGSIZE
- OFFSET(i
, IO_TLB_SEGSIZE
);
221 io_tlb_orig_addr
= (unsigned char **)__get_free_pages(GFP_KERNEL
,
222 get_order(io_tlb_nslabs
* sizeof(char *)));
223 if (!io_tlb_orig_addr
)
226 memset(io_tlb_orig_addr
, 0, io_tlb_nslabs
* sizeof(char *));
229 * Get the overflow emergency buffer
231 io_tlb_overflow_buffer
= (void *)__get_free_pages(GFP_DMA
,
232 get_order(io_tlb_overflow
));
233 if (!io_tlb_overflow_buffer
)
236 printk(KERN_INFO
"Placing %ldMB software IO TLB between 0x%lx - "
237 "0x%lx\n", (io_tlb_nslabs
* (1 << IO_TLB_SHIFT
)) >> 20,
238 virt_to_phys(io_tlb_start
), virt_to_phys(io_tlb_end
));
243 free_pages((unsigned long)io_tlb_orig_addr
, get_order(io_tlb_nslabs
*
245 io_tlb_orig_addr
= NULL
;
247 free_pages((unsigned long)io_tlb_list
, get_order(io_tlb_nslabs
*
252 free_pages((unsigned long)io_tlb_start
, order
);
255 io_tlb_nslabs
= req_nslabs
;
260 address_needs_mapping(struct device
*hwdev
, dma_addr_t addr
)
262 dma_addr_t mask
= 0xffffffff;
263 /* If the device has a mask, use it, otherwise default to 32 bits */
264 if (hwdev
&& hwdev
->dma_mask
)
265 mask
= *hwdev
->dma_mask
;
266 return (addr
& ~mask
) != 0;
270 * Allocates bounce buffer and returns its kernel virtual address.
273 map_single(struct device
*hwdev
, char *buffer
, size_t size
, int dir
)
277 unsigned int nslots
, stride
, index
, wrap
;
281 * For mappings greater than a page, we limit the stride (and
282 * hence alignment) to a page size.
284 nslots
= ALIGN(size
, 1 << IO_TLB_SHIFT
) >> IO_TLB_SHIFT
;
285 if (size
> PAGE_SIZE
)
286 stride
= (1 << (PAGE_SHIFT
- IO_TLB_SHIFT
));
294 * Find suitable number of IO TLB entries size that will fit this
295 * request and allocate a buffer from that IO TLB pool.
297 spin_lock_irqsave(&io_tlb_lock
, flags
);
299 wrap
= index
= ALIGN(io_tlb_index
, stride
);
301 if (index
>= io_tlb_nslabs
)
306 * If we find a slot that indicates we have 'nslots'
307 * number of contiguous buffers, we allocate the
308 * buffers from that slot and mark the entries as '0'
309 * indicating unavailable.
311 if (io_tlb_list
[index
] >= nslots
) {
314 for (i
= index
; i
< (int) (index
+ nslots
); i
++)
316 for (i
= index
- 1; (OFFSET(i
, IO_TLB_SEGSIZE
) != IO_TLB_SEGSIZE
-1) && io_tlb_list
[i
]; i
--)
317 io_tlb_list
[i
] = ++count
;
318 dma_addr
= io_tlb_start
+ (index
<< IO_TLB_SHIFT
);
321 * Update the indices to avoid searching in
324 io_tlb_index
= ((index
+ nslots
) < io_tlb_nslabs
325 ? (index
+ nslots
) : 0);
330 if (index
>= io_tlb_nslabs
)
332 } while (index
!= wrap
);
334 spin_unlock_irqrestore(&io_tlb_lock
, flags
);
338 spin_unlock_irqrestore(&io_tlb_lock
, flags
);
341 * Save away the mapping from the original address to the DMA address.
342 * This is needed when we sync the memory. Then we sync the buffer if
345 io_tlb_orig_addr
[index
] = buffer
;
346 if (dir
== DMA_TO_DEVICE
|| dir
== DMA_BIDIRECTIONAL
)
347 memcpy(dma_addr
, buffer
, size
);
353 * dma_addr is the kernel virtual address of the bounce buffer to unmap.
356 unmap_single(struct device
*hwdev
, char *dma_addr
, size_t size
, int dir
)
359 int i
, count
, nslots
= ALIGN(size
, 1 << IO_TLB_SHIFT
) >> IO_TLB_SHIFT
;
360 int index
= (dma_addr
- io_tlb_start
) >> IO_TLB_SHIFT
;
361 char *buffer
= io_tlb_orig_addr
[index
];
364 * First, sync the memory before unmapping the entry
366 if (buffer
&& ((dir
== DMA_FROM_DEVICE
) || (dir
== DMA_BIDIRECTIONAL
)))
368 * bounce... copy the data back into the original buffer * and
369 * delete the bounce buffer.
371 memcpy(buffer
, dma_addr
, size
);
374 * Return the buffer to the free list by setting the corresponding
375 * entries to indicate the number of contigous entries available.
376 * While returning the entries to the free list, we merge the entries
377 * with slots below and above the pool being returned.
379 spin_lock_irqsave(&io_tlb_lock
, flags
);
381 count
= ((index
+ nslots
) < ALIGN(index
+ 1, IO_TLB_SEGSIZE
) ?
382 io_tlb_list
[index
+ nslots
] : 0);
384 * Step 1: return the slots to the free list, merging the
385 * slots with superceeding slots
387 for (i
= index
+ nslots
- 1; i
>= index
; i
--)
388 io_tlb_list
[i
] = ++count
;
390 * Step 2: merge the returned slots with the preceding slots,
391 * if available (non zero)
393 for (i
= index
- 1; (OFFSET(i
, IO_TLB_SEGSIZE
) != IO_TLB_SEGSIZE
-1) && io_tlb_list
[i
]; i
--)
394 io_tlb_list
[i
] = ++count
;
396 spin_unlock_irqrestore(&io_tlb_lock
, flags
);
400 sync_single(struct device
*hwdev
, char *dma_addr
, size_t size
, int dir
)
402 int index
= (dma_addr
- io_tlb_start
) >> IO_TLB_SHIFT
;
403 char *buffer
= io_tlb_orig_addr
[index
];
406 * bounce... copy the data back into/from the original buffer
407 * XXX How do you handle DMA_BIDIRECTIONAL here ?
409 if (dir
== DMA_FROM_DEVICE
)
410 memcpy(buffer
, dma_addr
, size
);
411 else if (dir
== DMA_TO_DEVICE
)
412 memcpy(dma_addr
, buffer
, size
);
418 swiotlb_alloc_coherent(struct device
*hwdev
, size_t size
,
419 dma_addr_t
*dma_handle
, int flags
)
421 unsigned long dev_addr
;
423 int order
= get_order(size
);
426 * XXX fix me: the DMA API should pass us an explicit DMA mask
427 * instead, or use ZONE_DMA32 (ia64 overloads ZONE_DMA to be a ~32
428 * bit range instead of a 16MB one).
432 ret
= (void *)__get_free_pages(flags
, order
);
433 if (ret
&& address_needs_mapping(hwdev
, virt_to_phys(ret
))) {
435 * The allocated memory isn't reachable by the device.
436 * Fall back on swiotlb_map_single().
438 free_pages((unsigned long) ret
, order
);
443 * We are either out of memory or the device can't DMA
444 * to GFP_DMA memory; fall back on
445 * swiotlb_map_single(), which will grab memory from
446 * the lowest available address range.
449 handle
= swiotlb_map_single(NULL
, NULL
, size
, DMA_FROM_DEVICE
);
450 if (dma_mapping_error(handle
))
453 ret
= phys_to_virt(handle
);
456 memset(ret
, 0, size
);
457 dev_addr
= virt_to_phys(ret
);
459 /* Confirm address can be DMA'd by device */
460 if (address_needs_mapping(hwdev
, dev_addr
)) {
461 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016lx\n",
462 (unsigned long long)*hwdev
->dma_mask
, dev_addr
);
463 panic("swiotlb_alloc_coherent: allocated memory is out of "
466 *dma_handle
= dev_addr
;
471 swiotlb_free_coherent(struct device
*hwdev
, size_t size
, void *vaddr
,
472 dma_addr_t dma_handle
)
474 if (!(vaddr
>= (void *)io_tlb_start
475 && vaddr
< (void *)io_tlb_end
))
476 free_pages((unsigned long) vaddr
, get_order(size
));
478 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
479 swiotlb_unmap_single (hwdev
, dma_handle
, size
, DMA_TO_DEVICE
);
483 swiotlb_full(struct device
*dev
, size_t size
, int dir
, int do_panic
)
486 * Ran out of IOMMU space for this operation. This is very bad.
487 * Unfortunately the drivers cannot handle this operation properly.
488 * unless they check for pci_dma_mapping_error (most don't)
489 * When the mapping is small enough return a static buffer to limit
490 * the damage, or panic when the transfer is too big.
492 printk(KERN_ERR
"PCI-DMA: Out of SW-IOMMU space for %lu bytes at "
493 "device %s\n", size
, dev
? dev
->bus_id
: "?");
495 if (size
> io_tlb_overflow
&& do_panic
) {
496 if (dir
== PCI_DMA_FROMDEVICE
|| dir
== PCI_DMA_BIDIRECTIONAL
)
497 panic("PCI-DMA: Memory would be corrupted\n");
498 if (dir
== PCI_DMA_TODEVICE
|| dir
== PCI_DMA_BIDIRECTIONAL
)
499 panic("PCI-DMA: Random memory would be DMAed\n");
504 * Map a single buffer of the indicated size for DMA in streaming mode. The
505 * PCI address to use is returned.
507 * Once the device is given the dma address, the device owns this memory until
508 * either swiotlb_unmap_single or swiotlb_dma_sync_single is performed.
511 swiotlb_map_single(struct device
*hwdev
, void *ptr
, size_t size
, int dir
)
513 unsigned long dev_addr
= virt_to_phys(ptr
);
519 * If the pointer passed in happens to be in the device's DMA window,
520 * we can safely return the device addr and not worry about bounce
523 if (!address_needs_mapping(hwdev
, dev_addr
) && !swiotlb_force
)
527 * Oh well, have to allocate and map a bounce buffer.
529 map
= map_single(hwdev
, ptr
, size
, dir
);
531 swiotlb_full(hwdev
, size
, dir
, 1);
532 map
= io_tlb_overflow_buffer
;
535 dev_addr
= virt_to_phys(map
);
538 * Ensure that the address returned is DMA'ble
540 if (address_needs_mapping(hwdev
, dev_addr
))
541 panic("map_single: bounce buffer is not DMA'ble");
547 * Since DMA is i-cache coherent, any (complete) pages that were written via
548 * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
549 * flush them when they get mapped into an executable vm-area.
552 mark_clean(void *addr
, size_t size
)
554 unsigned long pg_addr
, end
;
556 pg_addr
= PAGE_ALIGN((unsigned long) addr
);
557 end
= (unsigned long) addr
+ size
;
558 while (pg_addr
+ PAGE_SIZE
<= end
) {
559 struct page
*page
= virt_to_page(pg_addr
);
560 set_bit(PG_arch_1
, &page
->flags
);
561 pg_addr
+= PAGE_SIZE
;
566 * Unmap a single streaming mode DMA translation. The dma_addr and size must
567 * match what was provided for in a previous swiotlb_map_single call. All
568 * other usages are undefined.
570 * After this call, reads by the cpu to the buffer are guaranteed to see
571 * whatever the device wrote there.
574 swiotlb_unmap_single(struct device
*hwdev
, dma_addr_t dev_addr
, size_t size
,
577 char *dma_addr
= phys_to_virt(dev_addr
);
581 if (dma_addr
>= io_tlb_start
&& dma_addr
< io_tlb_end
)
582 unmap_single(hwdev
, dma_addr
, size
, dir
);
583 else if (dir
== DMA_FROM_DEVICE
)
584 mark_clean(dma_addr
, size
);
588 * Make physical memory consistent for a single streaming mode DMA translation
591 * If you perform a swiotlb_map_single() but wish to interrogate the buffer
592 * using the cpu, yet do not wish to teardown the PCI dma mapping, you must
593 * call this function before doing so. At the next point you give the PCI dma
594 * address back to the card, you must first perform a
595 * swiotlb_dma_sync_for_device, and then the device again owns the buffer
598 swiotlb_sync_single_for_cpu(struct device
*hwdev
, dma_addr_t dev_addr
,
599 size_t size
, int dir
)
601 char *dma_addr
= phys_to_virt(dev_addr
);
605 if (dma_addr
>= io_tlb_start
&& dma_addr
< io_tlb_end
)
606 sync_single(hwdev
, dma_addr
, size
, dir
);
607 else if (dir
== DMA_FROM_DEVICE
)
608 mark_clean(dma_addr
, size
);
612 swiotlb_sync_single_for_device(struct device
*hwdev
, dma_addr_t dev_addr
,
613 size_t size
, int dir
)
615 char *dma_addr
= phys_to_virt(dev_addr
);
619 if (dma_addr
>= io_tlb_start
&& dma_addr
< io_tlb_end
)
620 sync_single(hwdev
, dma_addr
, size
, dir
);
621 else if (dir
== DMA_FROM_DEVICE
)
622 mark_clean(dma_addr
, size
);
626 * Map a set of buffers described by scatterlist in streaming mode for DMA.
627 * This is the scatter-gather version of the above swiotlb_map_single
628 * interface. Here the scatter gather list elements are each tagged with the
629 * appropriate dma address and length. They are obtained via
630 * sg_dma_{address,length}(SG).
632 * NOTE: An implementation may be able to use a smaller number of
633 * DMA address/length pairs than there are SG table elements.
634 * (for example via virtual mapping capabilities)
635 * The routine returns the number of addr/length pairs actually
636 * used, at most nents.
638 * Device ownership issues as mentioned above for swiotlb_map_single are the
642 swiotlb_map_sg(struct device
*hwdev
, struct scatterlist
*sg
, int nelems
,
646 unsigned long dev_addr
;
652 for (i
= 0; i
< nelems
; i
++, sg
++) {
653 addr
= SG_ENT_VIRT_ADDRESS(sg
);
654 dev_addr
= virt_to_phys(addr
);
655 if (swiotlb_force
|| address_needs_mapping(hwdev
, dev_addr
)) {
656 sg
->dma_address
= (dma_addr_t
) virt_to_phys(map_single(hwdev
, addr
, sg
->length
, dir
));
657 if (!sg
->dma_address
) {
658 /* Don't panic here, we expect map_sg users
659 to do proper error handling. */
660 swiotlb_full(hwdev
, sg
->length
, dir
, 0);
661 swiotlb_unmap_sg(hwdev
, sg
- i
, i
, dir
);
662 sg
[0].dma_length
= 0;
666 sg
->dma_address
= dev_addr
;
667 sg
->dma_length
= sg
->length
;
673 * Unmap a set of streaming mode DMA translations. Again, cpu read rules
674 * concerning calls here are the same as for swiotlb_unmap_single() above.
677 swiotlb_unmap_sg(struct device
*hwdev
, struct scatterlist
*sg
, int nelems
,
685 for (i
= 0; i
< nelems
; i
++, sg
++)
686 if (sg
->dma_address
!= SG_ENT_PHYS_ADDRESS(sg
))
687 unmap_single(hwdev
, (void *) phys_to_virt(sg
->dma_address
), sg
->dma_length
, dir
);
688 else if (dir
== DMA_FROM_DEVICE
)
689 mark_clean(SG_ENT_VIRT_ADDRESS(sg
), sg
->dma_length
);
693 * Make physical memory consistent for a set of streaming mode DMA translations
696 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
700 swiotlb_sync_sg_for_cpu(struct device
*hwdev
, struct scatterlist
*sg
,
708 for (i
= 0; i
< nelems
; i
++, sg
++)
709 if (sg
->dma_address
!= SG_ENT_PHYS_ADDRESS(sg
))
710 sync_single(hwdev
, (void *) sg
->dma_address
,
711 sg
->dma_length
, dir
);
715 swiotlb_sync_sg_for_device(struct device
*hwdev
, struct scatterlist
*sg
,
723 for (i
= 0; i
< nelems
; i
++, sg
++)
724 if (sg
->dma_address
!= SG_ENT_PHYS_ADDRESS(sg
))
725 sync_single(hwdev
, (void *) sg
->dma_address
,
726 sg
->dma_length
, dir
);
730 swiotlb_dma_mapping_error(dma_addr_t dma_addr
)
732 return (dma_addr
== virt_to_phys(io_tlb_overflow_buffer
));
736 * Return whether the given PCI device DMA address mask can be supported
737 * properly. For example, if your device can only drive the low 24-bits
738 * during PCI bus mastering, then you would pass 0x00ffffff as the mask to
742 swiotlb_dma_supported (struct device
*hwdev
, u64 mask
)
744 return (virt_to_phys (io_tlb_end
) - 1) <= mask
;
747 EXPORT_SYMBOL(swiotlb_init
);
748 EXPORT_SYMBOL(swiotlb_map_single
);
749 EXPORT_SYMBOL(swiotlb_unmap_single
);
750 EXPORT_SYMBOL(swiotlb_map_sg
);
751 EXPORT_SYMBOL(swiotlb_unmap_sg
);
752 EXPORT_SYMBOL(swiotlb_sync_single_for_cpu
);
753 EXPORT_SYMBOL(swiotlb_sync_single_for_device
);
754 EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu
);
755 EXPORT_SYMBOL(swiotlb_sync_sg_for_device
);
756 EXPORT_SYMBOL(swiotlb_dma_mapping_error
);
757 EXPORT_SYMBOL(swiotlb_alloc_coherent
);
758 EXPORT_SYMBOL(swiotlb_free_coherent
);
759 EXPORT_SYMBOL(swiotlb_dma_supported
);