blob: dc1cd1f5369e3fb0e3e089140bfd49ff9096a7bd [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Dynamic DMA mapping support.
3 *
Jan Beulich563aaf02007-02-05 18:51:25 -08004 * This implementation is a fallback for platforms that do not support
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * 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>
10 *
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.
John W. Linville569c8bf2005-09-29 14:45:24 -070014 * 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.
Becky Brucefb05a372008-12-22 10:26:09 -080017 * 08/12/11 beckyb Add highmem support
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 */
19
20#include <linux/cache.h>
Tony Luck17e5ad62005-09-29 15:52:13 -070021#include <linux/dma-mapping.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/mm.h>
23#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/spinlock.h>
25#include <linux/string.h>
Ian Campbell0016fde2008-12-16 12:17:27 -080026#include <linux/swiotlb.h>
Becky Brucefb05a372008-12-22 10:26:09 -080027#include <linux/pfn.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/types.h>
29#include <linux/ctype.h>
Jeremy Fitzhardingeef9b1892008-12-16 12:17:33 -080030#include <linux/highmem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <asm/dma.h>
Tony Luck17e5ad62005-09-29 15:52:13 -070034#include <asm/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36#include <linux/init.h>
37#include <linux/bootmem.h>
FUJITA Tomonoria8522502008-04-29 00:59:36 -070038#include <linux/iommu-helper.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#define OFFSET(val,align) ((unsigned long) \
41 ( (val) & ( (align) - 1)))
42
Alex Williamson0b9afed2005-09-06 11:20:49 -060043#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
44
45/*
46 * Minimum IO TLB size to bother booting with. Systems with mainly
47 * 64bit capable cards will only lightly use the swiotlb. If we can't
48 * allocate a contiguous 1MB, we're probably in trouble anyway.
49 */
50#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
51
John W. Linvillede69e0f2005-09-29 14:44:57 -070052/*
53 * Enumeration for sync targets
54 */
55enum dma_sync_target {
56 SYNC_FOR_CPU = 0,
57 SYNC_FOR_DEVICE = 1,
58};
59
Linus Torvalds1da177e2005-04-16 15:20:36 -070060int swiotlb_force;
61
62/*
Becky Bruceceb5ac32009-04-08 09:09:15 -050063 * Used to do a quick range check in unmap_single and
64 * sync_single_*, to see if the memory was in fact allocated by this
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 * API.
66 */
67static char *io_tlb_start, *io_tlb_end;
68
69/*
70 * The number of IO TLB blocks (in groups of 64) betweeen io_tlb_start and
71 * io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
72 */
73static unsigned long io_tlb_nslabs;
74
75/*
76 * When the IOMMU overflows we return a fallback buffer. This sets the size.
77 */
78static unsigned long io_tlb_overflow = 32*1024;
79
80void *io_tlb_overflow_buffer;
81
82/*
83 * This is a free list describing the number of free entries available from
84 * each index
85 */
86static unsigned int *io_tlb_list;
87static unsigned int io_tlb_index;
88
89/*
90 * We need to save away the original address corresponding to a mapped entry
91 * for the sync operations.
92 */
Becky Brucebc40ac62008-12-22 10:26:08 -080093static phys_addr_t *io_tlb_orig_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
95/*
96 * Protect the above data structures in the map and unmap calls
97 */
98static DEFINE_SPINLOCK(io_tlb_lock);
99
100static int __init
101setup_io_tlb_npages(char *str)
102{
103 if (isdigit(*str)) {
Alex Williamsone8579e72005-08-04 13:06:00 -0700104 io_tlb_nslabs = simple_strtoul(str, &str, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 /* avoid tail segment of size < IO_TLB_SEGSIZE */
106 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
107 }
108 if (*str == ',')
109 ++str;
110 if (!strcmp(str, "force"))
111 swiotlb_force = 1;
112 return 1;
113}
114__setup("swiotlb=", setup_io_tlb_npages);
115/* make io_tlb_overflow tunable too? */
116
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800117dma_addr_t __weak swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800118{
119 return paddr;
120}
121
Becky Bruce42d7c5e2009-04-08 09:09:21 -0500122phys_addr_t __weak swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800123{
124 return baddr;
125}
126
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800127static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
128 volatile void *address)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800129{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800130 return swiotlb_phys_to_bus(hwdev, virt_to_phys(address));
Ian Campbelle08e1f72008-12-16 12:17:30 -0800131}
132
Becky Bruce42d7c5e2009-04-08 09:09:21 -0500133void * __weak swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t address)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800134{
Becky Bruce42d7c5e2009-04-08 09:09:21 -0500135 return phys_to_virt(swiotlb_bus_to_phys(hwdev, address));
Ian Campbelle08e1f72008-12-16 12:17:30 -0800136}
137
Becky Bruceef5722f2009-04-08 09:09:18 -0500138int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
139 dma_addr_t addr, size_t size)
140{
141 return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
142}
143
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800144static void swiotlb_print_info(unsigned long bytes)
145{
146 phys_addr_t pstart, pend;
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800147
148 pstart = virt_to_phys(io_tlb_start);
149 pend = virt_to_phys(io_tlb_end);
150
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800151 printk(KERN_INFO "Placing %luMB software IO TLB between %p - %p\n",
152 bytes >> 20, io_tlb_start, io_tlb_end);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800153 printk(KERN_INFO "software IO TLB at phys %#llx - %#llx\n",
154 (unsigned long long)pstart,
155 (unsigned long long)pend);
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800156}
157
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158/*
159 * Statically reserve bounce buffer space and initialize bounce buffer data
Tony Luck17e5ad62005-09-29 15:52:13 -0700160 * structures for the software IO TLB used to implement the DMA API.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800162void __init
163swiotlb_init_with_default_size(size_t default_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164{
Jan Beulich563aaf02007-02-05 18:51:25 -0800165 unsigned long i, bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
167 if (!io_tlb_nslabs) {
Alex Williamsone8579e72005-08-04 13:06:00 -0700168 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
170 }
171
Jan Beulich563aaf02007-02-05 18:51:25 -0800172 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
173
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 /*
175 * Get IO TLB memory from the low pages
176 */
FUJITA Tomonori38851232009-07-10 10:04:50 +0900177 io_tlb_start = alloc_bootmem_low_pages(bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 if (!io_tlb_start)
179 panic("Cannot allocate SWIOTLB buffer");
Jan Beulich563aaf02007-02-05 18:51:25 -0800180 io_tlb_end = io_tlb_start + bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 /*
183 * Allocate and initialize the free list array. This array is used
184 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
185 * between io_tlb_start and io_tlb_end.
186 */
187 io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
Tony Luck25667d62007-03-06 13:31:45 -0800188 for (i = 0; i < io_tlb_nslabs; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
190 io_tlb_index = 0;
Becky Brucebc40ac62008-12-22 10:26:08 -0800191 io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
193 /*
194 * Get the overflow emergency buffer
195 */
196 io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
Jan Beulich563aaf02007-02-05 18:51:25 -0800197 if (!io_tlb_overflow_buffer)
198 panic("Cannot allocate SWIOTLB overflow buffer!\n");
199
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800200 swiotlb_print_info(bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201}
202
Jan Beulich563aaf02007-02-05 18:51:25 -0800203void __init
204swiotlb_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205{
Tony Luck25667d62007-03-06 13:31:45 -0800206 swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207}
208
Alex Williamson0b9afed2005-09-06 11:20:49 -0600209/*
210 * Systems with larger DMA zones (those that don't support ISA) can
211 * initialize the swiotlb later using the slab allocator if needed.
212 * This should be just like above, but with some error catching.
213 */
214int
Jan Beulich563aaf02007-02-05 18:51:25 -0800215swiotlb_late_init_with_default_size(size_t default_size)
Alex Williamson0b9afed2005-09-06 11:20:49 -0600216{
Jan Beulich563aaf02007-02-05 18:51:25 -0800217 unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600218 unsigned int order;
219
220 if (!io_tlb_nslabs) {
221 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
222 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
223 }
224
225 /*
226 * Get IO TLB memory from the low pages
227 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800228 order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600229 io_tlb_nslabs = SLABS_PER_PAGE << order;
Jan Beulich563aaf02007-02-05 18:51:25 -0800230 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600231
232 while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
FUJITA Tomonoribb521962009-07-10 10:04:51 +0900233 io_tlb_start = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
234 order);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600235 if (io_tlb_start)
236 break;
237 order--;
238 }
239
240 if (!io_tlb_start)
241 goto cleanup1;
242
Jan Beulich563aaf02007-02-05 18:51:25 -0800243 if (order != get_order(bytes)) {
Alex Williamson0b9afed2005-09-06 11:20:49 -0600244 printk(KERN_WARNING "Warning: only able to allocate %ld MB "
245 "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
246 io_tlb_nslabs = SLABS_PER_PAGE << order;
Jan Beulich563aaf02007-02-05 18:51:25 -0800247 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600248 }
Jan Beulich563aaf02007-02-05 18:51:25 -0800249 io_tlb_end = io_tlb_start + bytes;
250 memset(io_tlb_start, 0, bytes);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600251
252 /*
253 * Allocate and initialize the free list array. This array is used
254 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
255 * between io_tlb_start and io_tlb_end.
256 */
257 io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
258 get_order(io_tlb_nslabs * sizeof(int)));
259 if (!io_tlb_list)
260 goto cleanup2;
261
262 for (i = 0; i < io_tlb_nslabs; i++)
263 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
264 io_tlb_index = 0;
265
Becky Brucebc40ac62008-12-22 10:26:08 -0800266 io_tlb_orig_addr = (phys_addr_t *)
267 __get_free_pages(GFP_KERNEL,
268 get_order(io_tlb_nslabs *
269 sizeof(phys_addr_t)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600270 if (!io_tlb_orig_addr)
271 goto cleanup3;
272
Becky Brucebc40ac62008-12-22 10:26:08 -0800273 memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600274
275 /*
276 * Get the overflow emergency buffer
277 */
278 io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
279 get_order(io_tlb_overflow));
280 if (!io_tlb_overflow_buffer)
281 goto cleanup4;
282
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800283 swiotlb_print_info(bytes);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600284
285 return 0;
286
287cleanup4:
Becky Brucebc40ac62008-12-22 10:26:08 -0800288 free_pages((unsigned long)io_tlb_orig_addr,
289 get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600290 io_tlb_orig_addr = NULL;
291cleanup3:
Tony Luck25667d62007-03-06 13:31:45 -0800292 free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
293 sizeof(int)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600294 io_tlb_list = NULL;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600295cleanup2:
Jan Beulich563aaf02007-02-05 18:51:25 -0800296 io_tlb_end = NULL;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600297 free_pages((unsigned long)io_tlb_start, order);
298 io_tlb_start = NULL;
299cleanup1:
300 io_tlb_nslabs = req_nslabs;
301 return -ENOMEM;
302}
303
Becky Bruceef5722f2009-04-08 09:09:18 -0500304static inline int
FUJITA Tomonori27979822008-09-10 01:06:49 +0900305address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306{
Becky Bruceef5722f2009-04-08 09:09:18 -0500307 return swiotlb_arch_address_needs_mapping(hwdev, addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308}
309
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900310static int is_swiotlb_buffer(char *addr)
311{
312 return addr >= io_tlb_start && addr < io_tlb_end;
313}
314
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315/*
Becky Brucefb05a372008-12-22 10:26:09 -0800316 * Bounce: copy the swiotlb buffer back to the original dma location
317 */
318static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
319 enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
Becky Brucefb05a372008-12-22 10:26:09 -0800321 unsigned long pfn = PFN_DOWN(phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322
Becky Brucefb05a372008-12-22 10:26:09 -0800323 if (PageHighMem(pfn_to_page(pfn))) {
324 /* The buffer does not have a mapping. Map it in and copy */
325 unsigned int offset = phys & ~PAGE_MASK;
326 char *buffer;
327 unsigned int sz = 0;
328 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Becky Brucefb05a372008-12-22 10:26:09 -0800330 while (size) {
Becky Bruce67131ad2009-04-08 09:09:16 -0500331 sz = min_t(size_t, PAGE_SIZE - offset, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332
Becky Brucefb05a372008-12-22 10:26:09 -0800333 local_irq_save(flags);
334 buffer = kmap_atomic(pfn_to_page(pfn),
335 KM_BOUNCE_READ);
336 if (dir == DMA_TO_DEVICE)
337 memcpy(dma_addr, buffer + offset, sz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 else
Becky Brucefb05a372008-12-22 10:26:09 -0800339 memcpy(buffer + offset, dma_addr, sz);
340 kunmap_atomic(buffer, KM_BOUNCE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 local_irq_restore(flags);
Becky Brucefb05a372008-12-22 10:26:09 -0800342
343 size -= sz;
344 pfn++;
345 dma_addr += sz;
346 offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 }
348 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 if (dir == DMA_TO_DEVICE)
Becky Brucefb05a372008-12-22 10:26:09 -0800350 memcpy(dma_addr, phys_to_virt(phys), size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 else
Becky Brucefb05a372008-12-22 10:26:09 -0800352 memcpy(phys_to_virt(phys), dma_addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 }
354}
355
356/*
357 * Allocates bounce buffer and returns its kernel virtual address.
358 */
359static void *
Becky Brucebc40ac62008-12-22 10:26:08 -0800360map_single(struct device *hwdev, phys_addr_t phys, size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361{
362 unsigned long flags;
363 char *dma_addr;
364 unsigned int nslots, stride, index, wrap;
365 int i;
FUJITA Tomonori681cc5c2008-02-04 22:28:16 -0800366 unsigned long start_dma_addr;
367 unsigned long mask;
368 unsigned long offset_slots;
369 unsigned long max_slots;
370
371 mask = dma_get_seg_boundary(hwdev);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800372 start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start) & mask;
FUJITA Tomonori681cc5c2008-02-04 22:28:16 -0800373
374 offset_slots = ALIGN(start_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
Ian Campbella5ddde4a2008-12-16 12:17:29 -0800375
376 /*
377 * Carefully handle integer overflow which can occur when mask == ~0UL.
378 */
Jan Beulichb15a38912008-03-13 09:13:30 +0000379 max_slots = mask + 1
380 ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
381 : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
383 /*
384 * For mappings greater than a page, we limit the stride (and
385 * hence alignment) to a page size.
386 */
387 nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
388 if (size > PAGE_SIZE)
389 stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
390 else
391 stride = 1;
392
Eric Sesterhenn34814542006-03-24 18:47:11 +0100393 BUG_ON(!nslots);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 /*
396 * Find suitable number of IO TLB entries size that will fit this
397 * request and allocate a buffer from that IO TLB pool.
398 */
399 spin_lock_irqsave(&io_tlb_lock, flags);
Andrew Mortona7133a12008-04-29 00:59:36 -0700400 index = ALIGN(io_tlb_index, stride);
401 if (index >= io_tlb_nslabs)
402 index = 0;
403 wrap = index;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
Andrew Mortona7133a12008-04-29 00:59:36 -0700405 do {
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700406 while (iommu_is_span_boundary(index, nslots, offset_slots,
407 max_slots)) {
Jan Beulichb15a38912008-03-13 09:13:30 +0000408 index += stride;
409 if (index >= io_tlb_nslabs)
410 index = 0;
Andrew Mortona7133a12008-04-29 00:59:36 -0700411 if (index == wrap)
412 goto not_found;
413 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Andrew Mortona7133a12008-04-29 00:59:36 -0700415 /*
416 * If we find a slot that indicates we have 'nslots' number of
417 * contiguous buffers, we allocate the buffers from that slot
418 * and mark the entries as '0' indicating unavailable.
419 */
420 if (io_tlb_list[index] >= nslots) {
421 int count = 0;
422
423 for (i = index; i < (int) (index + nslots); i++)
424 io_tlb_list[i] = 0;
425 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
426 io_tlb_list[i] = ++count;
427 dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
428
429 /*
430 * Update the indices to avoid searching in the next
431 * round.
432 */
433 io_tlb_index = ((index + nslots) < io_tlb_nslabs
434 ? (index + nslots) : 0);
435
436 goto found;
437 }
438 index += stride;
439 if (index >= io_tlb_nslabs)
440 index = 0;
441 } while (index != wrap);
442
443not_found:
444 spin_unlock_irqrestore(&io_tlb_lock, flags);
445 return NULL;
446found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 spin_unlock_irqrestore(&io_tlb_lock, flags);
448
449 /*
450 * Save away the mapping from the original address to the DMA address.
451 * This is needed when we sync the memory. Then we sync the buffer if
452 * needed.
453 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800454 for (i = 0; i < nslots; i++)
455 io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
Becky Brucefb05a372008-12-22 10:26:09 -0800457 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458
459 return dma_addr;
460}
461
462/*
463 * dma_addr is the kernel virtual address of the bounce buffer to unmap.
464 */
465static void
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500466do_unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467{
468 unsigned long flags;
469 int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
470 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
Becky Brucebc40ac62008-12-22 10:26:08 -0800471 phys_addr_t phys = io_tlb_orig_addr[index];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
473 /*
474 * First, sync the memory before unmapping the entry
475 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800476 if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
Becky Brucefb05a372008-12-22 10:26:09 -0800477 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
479 /*
480 * Return the buffer to the free list by setting the corresponding
481 * entries to indicate the number of contigous entries available.
482 * While returning the entries to the free list, we merge the entries
483 * with slots below and above the pool being returned.
484 */
485 spin_lock_irqsave(&io_tlb_lock, flags);
486 {
487 count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
488 io_tlb_list[index + nslots] : 0);
489 /*
490 * Step 1: return the slots to the free list, merging the
491 * slots with superceeding slots
492 */
493 for (i = index + nslots - 1; i >= index; i--)
494 io_tlb_list[i] = ++count;
495 /*
496 * Step 2: merge the returned slots with the preceding slots,
497 * if available (non zero)
498 */
499 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
500 io_tlb_list[i] = ++count;
501 }
502 spin_unlock_irqrestore(&io_tlb_lock, flags);
503}
504
505static void
John W. Linvillede69e0f2005-09-29 14:44:57 -0700506sync_single(struct device *hwdev, char *dma_addr, size_t size,
507 int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508{
Becky Brucebc40ac62008-12-22 10:26:08 -0800509 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
510 phys_addr_t phys = io_tlb_orig_addr[index];
511
512 phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
Keir Fraserdf336d12007-07-21 04:37:24 -0700513
John W. Linvillede69e0f2005-09-29 14:44:57 -0700514 switch (target) {
515 case SYNC_FOR_CPU:
516 if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
Becky Brucefb05a372008-12-22 10:26:09 -0800517 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
Eric Sesterhenn34814542006-03-24 18:47:11 +0100518 else
519 BUG_ON(dir != DMA_TO_DEVICE);
John W. Linvillede69e0f2005-09-29 14:44:57 -0700520 break;
521 case SYNC_FOR_DEVICE:
522 if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
Becky Brucefb05a372008-12-22 10:26:09 -0800523 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
Eric Sesterhenn34814542006-03-24 18:47:11 +0100524 else
525 BUG_ON(dir != DMA_FROM_DEVICE);
John W. Linvillede69e0f2005-09-29 14:44:57 -0700526 break;
527 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 BUG();
John W. Linvillede69e0f2005-09-29 14:44:57 -0700529 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530}
531
532void *
533swiotlb_alloc_coherent(struct device *hwdev, size_t size,
Al Viro06a54492005-10-21 03:21:03 -0400534 dma_addr_t *dma_handle, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535{
Jan Beulich563aaf02007-02-05 18:51:25 -0800536 dma_addr_t dev_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 void *ret;
538 int order = get_order(size);
Yang Hongyang284901a2009-04-06 19:01:15 -0700539 u64 dma_mask = DMA_BIT_MASK(32);
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900540
541 if (hwdev && hwdev->coherent_dma_mask)
542 dma_mask = hwdev->coherent_dma_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
Tony Luck25667d62007-03-06 13:31:45 -0800544 ret = (void *)__get_free_pages(flags, order);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800545 if (ret &&
546 !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev, ret),
547 size)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 /*
549 * The allocated memory isn't reachable by the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 */
551 free_pages((unsigned long) ret, order);
552 ret = NULL;
553 }
554 if (!ret) {
555 /*
556 * We are either out of memory or the device can't DMA
Becky Bruceceb5ac32009-04-08 09:09:15 -0500557 * to GFP_DMA memory; fall back on map_single(), which
558 * will grab memory from the lowest available address range.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800560 ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
FUJITA Tomonori9dfda122008-09-08 18:53:48 +0900561 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 }
564
565 memset(ret, 0, size);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800566 dev_addr = swiotlb_virt_to_bus(hwdev, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 /* Confirm address can be DMA'd by device */
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900569 if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
Jan Beulich563aaf02007-02-05 18:51:25 -0800570 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900571 (unsigned long long)dma_mask,
Jan Beulich563aaf02007-02-05 18:51:25 -0800572 (unsigned long long)dev_addr);
FUJITA Tomonoria2b89b52008-10-23 18:42:03 +0900573
574 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500575 do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
FUJITA Tomonoria2b89b52008-10-23 18:42:03 +0900576 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 }
578 *dma_handle = dev_addr;
579 return ret;
580}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900581EXPORT_SYMBOL(swiotlb_alloc_coherent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
583void
584swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
585 dma_addr_t dma_handle)
586{
David Brownellaa248862007-08-10 13:10:27 -0700587 WARN_ON(irqs_disabled());
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900588 if (!is_swiotlb_buffer(vaddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 free_pages((unsigned long) vaddr, get_order(size));
590 else
591 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500592 do_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900594EXPORT_SYMBOL(swiotlb_free_coherent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
596static void
597swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
598{
599 /*
600 * Ran out of IOMMU space for this operation. This is very bad.
601 * Unfortunately the drivers cannot handle this operation properly.
Tony Luck17e5ad62005-09-29 15:52:13 -0700602 * unless they check for dma_mapping_error (most don't)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 * When the mapping is small enough return a static buffer to limit
604 * the damage, or panic when the transfer is too big.
605 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800606 printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
Kay Sievers94b32482009-01-06 10:44:37 -0800607 "device %s\n", size, dev ? dev_name(dev) : "?");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
609 if (size > io_tlb_overflow && do_panic) {
Tony Luck17e5ad62005-09-29 15:52:13 -0700610 if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
611 panic("DMA: Memory would be corrupted\n");
612 if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
613 panic("DMA: Random memory would be DMAed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 }
615}
616
617/*
618 * Map a single buffer of the indicated size for DMA in streaming mode. The
Tony Luck17e5ad62005-09-29 15:52:13 -0700619 * physical address to use is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 *
621 * Once the device is given the dma address, the device owns this memory until
Becky Bruceceb5ac32009-04-08 09:09:15 -0500622 * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900624dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
625 unsigned long offset, size_t size,
626 enum dma_data_direction dir,
627 struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628{
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900629 phys_addr_t phys = page_to_phys(page) + offset;
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900630 dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 void *map;
632
Eric Sesterhenn34814542006-03-24 18:47:11 +0100633 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 /*
Becky Bruceceb5ac32009-04-08 09:09:15 -0500635 * If the address happens to be in the device's DMA window,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 * we can safely return the device addr and not worry about bounce
637 * buffering it.
638 */
FUJITA Tomonoricf56e3f2009-07-10 10:04:52 +0900639 if (!address_needs_mapping(dev, dev_addr, size) && !swiotlb_force)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 return dev_addr;
641
642 /*
643 * Oh well, have to allocate and map a bounce buffer.
644 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900645 map = map_single(dev, phys, size, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 if (!map) {
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900647 swiotlb_full(dev, size, dir, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 map = io_tlb_overflow_buffer;
649 }
650
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900651 dev_addr = swiotlb_virt_to_bus(dev, map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
653 /*
654 * Ensure that the address returned is DMA'ble
655 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900656 if (address_needs_mapping(dev, dev_addr, size))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 panic("map_single: bounce buffer is not DMA'ble");
658
659 return dev_addr;
660}
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900661EXPORT_SYMBOL_GPL(swiotlb_map_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
663/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 * Unmap a single streaming mode DMA translation. The dma_addr and size must
Becky Bruceceb5ac32009-04-08 09:09:15 -0500665 * match what was provided for in a previous swiotlb_map_page call. All
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 * other usages are undefined.
667 *
668 * After this call, reads by the cpu to the buffer are guaranteed to see
669 * whatever the device wrote there.
670 */
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500671static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
672 size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673{
Becky Bruce42d7c5e2009-04-08 09:09:21 -0500674 char *dma_addr = swiotlb_bus_to_virt(hwdev, dev_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Eric Sesterhenn34814542006-03-24 18:47:11 +0100676 BUG_ON(dir == DMA_NONE);
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500677
678 if (is_swiotlb_buffer(dma_addr)) {
679 do_unmap_single(hwdev, dma_addr, size, dir);
680 return;
681 }
682
683 if (dir != DMA_FROM_DEVICE)
684 return;
685
686 dma_mark_clean(dma_addr, size);
687}
688
689void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
690 size_t size, enum dma_data_direction dir,
691 struct dma_attrs *attrs)
692{
693 unmap_single(hwdev, dev_addr, size, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694}
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900695EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900696
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697/*
698 * Make physical memory consistent for a single streaming mode DMA translation
699 * after a transfer.
700 *
Becky Bruceceb5ac32009-04-08 09:09:15 -0500701 * If you perform a swiotlb_map_page() but wish to interrogate the buffer
Tony Luck17e5ad62005-09-29 15:52:13 -0700702 * using the cpu, yet do not wish to teardown the dma mapping, you must
703 * call this function before doing so. At the next point you give the dma
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 * address back to the card, you must first perform a
705 * swiotlb_dma_sync_for_device, and then the device again owns the buffer
706 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800707static void
John W. Linville8270f3f2005-09-29 14:43:32 -0700708swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700709 size_t size, int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710{
Becky Bruce42d7c5e2009-04-08 09:09:21 -0500711 char *dma_addr = swiotlb_bus_to_virt(hwdev, dev_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712
Eric Sesterhenn34814542006-03-24 18:47:11 +0100713 BUG_ON(dir == DMA_NONE);
Becky Bruce380d6872009-04-08 09:09:20 -0500714
715 if (is_swiotlb_buffer(dma_addr)) {
John W. Linvillede69e0f2005-09-29 14:44:57 -0700716 sync_single(hwdev, dma_addr, size, dir, target);
Becky Bruce380d6872009-04-08 09:09:20 -0500717 return;
718 }
719
720 if (dir != DMA_FROM_DEVICE)
721 return;
722
723 dma_mark_clean(dma_addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724}
725
726void
John W. Linville8270f3f2005-09-29 14:43:32 -0700727swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900728 size_t size, enum dma_data_direction dir)
John W. Linville8270f3f2005-09-29 14:43:32 -0700729{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700730 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
John W. Linville8270f3f2005-09-29 14:43:32 -0700731}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900732EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
John W. Linville8270f3f2005-09-29 14:43:32 -0700733
734void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900736 size_t size, enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700738 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900740EXPORT_SYMBOL(swiotlb_sync_single_for_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
742/*
John W. Linville878a97c2005-09-29 14:44:23 -0700743 * Same as above, but for a sub-range of the mapping.
744 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800745static void
John W. Linville878a97c2005-09-29 14:44:23 -0700746swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700747 unsigned long offset, size_t size,
748 int dir, int target)
John W. Linville878a97c2005-09-29 14:44:23 -0700749{
Becky Bruce380d6872009-04-08 09:09:20 -0500750 swiotlb_sync_single(hwdev, dev_addr + offset, size, dir, target);
John W. Linville878a97c2005-09-29 14:44:23 -0700751}
752
753void
754swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900755 unsigned long offset, size_t size,
756 enum dma_data_direction dir)
John W. Linville878a97c2005-09-29 14:44:23 -0700757{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700758 swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
759 SYNC_FOR_CPU);
John W. Linville878a97c2005-09-29 14:44:23 -0700760}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900761EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu);
John W. Linville878a97c2005-09-29 14:44:23 -0700762
763void
764swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900765 unsigned long offset, size_t size,
766 enum dma_data_direction dir)
John W. Linville878a97c2005-09-29 14:44:23 -0700767{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700768 swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
769 SYNC_FOR_DEVICE);
John W. Linville878a97c2005-09-29 14:44:23 -0700770}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900771EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device);
John W. Linville878a97c2005-09-29 14:44:23 -0700772
773/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 * Map a set of buffers described by scatterlist in streaming mode for DMA.
Becky Bruceceb5ac32009-04-08 09:09:15 -0500775 * This is the scatter-gather version of the above swiotlb_map_page
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 * interface. Here the scatter gather list elements are each tagged with the
777 * appropriate dma address and length. They are obtained via
778 * sg_dma_{address,length}(SG).
779 *
780 * NOTE: An implementation may be able to use a smaller number of
781 * DMA address/length pairs than there are SG table elements.
782 * (for example via virtual mapping capabilities)
783 * The routine returns the number of addr/length pairs actually
784 * used, at most nents.
785 *
Becky Bruceceb5ac32009-04-08 09:09:15 -0500786 * Device ownership issues as mentioned above for swiotlb_map_page are the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 * same here.
788 */
789int
Arthur Kepner309df0c2008-04-29 01:00:32 -0700790swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900791 enum dma_data_direction dir, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200793 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 int i;
795
Eric Sesterhenn34814542006-03-24 18:47:11 +0100796 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797
Jens Axboedbfd49f2007-05-11 14:56:18 +0200798 for_each_sg(sgl, sg, nelems, i) {
Ian Campbell961d7d02009-01-09 18:32:10 +0000799 phys_addr_t paddr = sg_phys(sg);
800 dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
Becky Brucebc40ac62008-12-22 10:26:08 -0800801
FUJITA Tomonoricf56e3f2009-07-10 10:04:52 +0900802 if (swiotlb_force ||
FUJITA Tomonori27979822008-09-10 01:06:49 +0900803 address_needs_mapping(hwdev, dev_addr, sg->length)) {
Becky Brucebc40ac62008-12-22 10:26:08 -0800804 void *map = map_single(hwdev, sg_phys(sg),
805 sg->length, dir);
Andi Kleen7e870232005-12-20 14:45:19 +0100806 if (!map) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 /* Don't panic here, we expect map_sg users
808 to do proper error handling. */
809 swiotlb_full(hwdev, sg->length, dir, 0);
Arthur Kepner309df0c2008-04-29 01:00:32 -0700810 swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
811 attrs);
Jens Axboedbfd49f2007-05-11 14:56:18 +0200812 sgl[0].dma_length = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 return 0;
814 }
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800815 sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 } else
817 sg->dma_address = dev_addr;
818 sg->dma_length = sg->length;
819 }
820 return nelems;
821}
Arthur Kepner309df0c2008-04-29 01:00:32 -0700822EXPORT_SYMBOL(swiotlb_map_sg_attrs);
823
824int
825swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
826 int dir)
827{
828 return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
829}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900830EXPORT_SYMBOL(swiotlb_map_sg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
832/*
833 * Unmap a set of streaming mode DMA translations. Again, cpu read rules
Becky Bruceceb5ac32009-04-08 09:09:15 -0500834 * concerning calls here are the same as for swiotlb_unmap_page() above.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 */
836void
Arthur Kepner309df0c2008-04-29 01:00:32 -0700837swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900838 int nelems, enum dma_data_direction dir, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200840 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 int i;
842
Eric Sesterhenn34814542006-03-24 18:47:11 +0100843 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500845 for_each_sg(sgl, sg, nelems, i)
846 unmap_single(hwdev, sg->dma_address, sg->dma_length, dir);
847
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848}
Arthur Kepner309df0c2008-04-29 01:00:32 -0700849EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
850
851void
852swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
853 int dir)
854{
855 return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
856}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900857EXPORT_SYMBOL(swiotlb_unmap_sg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858
859/*
860 * Make physical memory consistent for a set of streaming mode DMA translations
861 * after a transfer.
862 *
863 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
864 * and usage.
865 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800866static void
Jens Axboedbfd49f2007-05-11 14:56:18 +0200867swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700868 int nelems, int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200870 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 int i;
872
Becky Bruce380d6872009-04-08 09:09:20 -0500873 for_each_sg(sgl, sg, nelems, i)
874 swiotlb_sync_single(hwdev, sg->dma_address,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700875 sg->dma_length, dir, target);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876}
877
878void
John W. Linville8270f3f2005-09-29 14:43:32 -0700879swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900880 int nelems, enum dma_data_direction dir)
John W. Linville8270f3f2005-09-29 14:43:32 -0700881{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700882 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
John W. Linville8270f3f2005-09-29 14:43:32 -0700883}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900884EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
John W. Linville8270f3f2005-09-29 14:43:32 -0700885
886void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900888 int nelems, enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700890 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900892EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893
894int
FUJITA Tomonori8d8bb392008-07-25 19:44:49 -0700895swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800897 return (dma_addr == swiotlb_virt_to_bus(hwdev, io_tlb_overflow_buffer));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900899EXPORT_SYMBOL(swiotlb_dma_mapping_error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
901/*
Tony Luck17e5ad62005-09-29 15:52:13 -0700902 * Return whether the given device DMA address mask can be supported
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 * properly. For example, if your device can only drive the low 24-bits
Tony Luck17e5ad62005-09-29 15:52:13 -0700904 * during bus mastering, then you would pass 0x00ffffff as the mask to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 * this function.
906 */
907int
Jan Beulich563aaf02007-02-05 18:51:25 -0800908swiotlb_dma_supported(struct device *hwdev, u64 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800910 return swiotlb_virt_to_bus(hwdev, io_tlb_end - 1) <= mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912EXPORT_SYMBOL(swiotlb_dma_supported);