blob: ec61e1507d0ac4f26ed77786546ff481a795cb55 [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090031#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33#include <asm/io.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <asm/dma.h>
Tony Luck17e5ad62005-09-29 15:52:13 -070035#include <asm/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#include <linux/init.h>
38#include <linux/bootmem.h>
FUJITA Tomonoria8522502008-04-29 00:59:36 -070039#include <linux/iommu-helper.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41#define OFFSET(val,align) ((unsigned long) \
42 ( (val) & ( (align) - 1)))
43
Alex Williamson0b9afed2005-09-06 11:20:49 -060044#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
45
46/*
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.
50 */
51#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
52
John W. Linvillede69e0f2005-09-29 14:44:57 -070053/*
54 * Enumeration for sync targets
55 */
56enum dma_sync_target {
57 SYNC_FOR_CPU = 0,
58 SYNC_FOR_DEVICE = 1,
59};
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061int swiotlb_force;
62
63/*
Becky Bruceceb5ac32009-04-08 09:09:15 -050064 * Used to do a quick range check in unmap_single and
65 * sync_single_*, to see if the memory was in fact allocated by this
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 * API.
67 */
68static char *io_tlb_start, *io_tlb_end;
69
70/*
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.
73 */
74static unsigned long io_tlb_nslabs;
75
76/*
77 * When the IOMMU overflows we return a fallback buffer. This sets the size.
78 */
79static unsigned long io_tlb_overflow = 32*1024;
80
81void *io_tlb_overflow_buffer;
82
83/*
84 * This is a free list describing the number of free entries available from
85 * each index
86 */
87static unsigned int *io_tlb_list;
88static unsigned int io_tlb_index;
89
90/*
91 * We need to save away the original address corresponding to a mapped entry
92 * for the sync operations.
93 */
Becky Brucebc40ac62008-12-22 10:26:08 -080094static phys_addr_t *io_tlb_orig_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96/*
97 * Protect the above data structures in the map and unmap calls
98 */
99static DEFINE_SPINLOCK(io_tlb_lock);
100
FUJITA Tomonori5740afd2009-11-10 19:46:18 +0900101static int late_alloc;
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103static int __init
104setup_io_tlb_npages(char *str)
105{
106 if (isdigit(*str)) {
Alex Williamsone8579e72005-08-04 13:06:00 -0700107 io_tlb_nslabs = simple_strtoul(str, &str, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 /* avoid tail segment of size < IO_TLB_SEGSIZE */
109 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
110 }
111 if (*str == ',')
112 ++str;
FUJITA Tomonorib18485e2009-11-12 00:03:28 +0900113 if (!strcmp(str, "force"))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 swiotlb_force = 1;
FUJITA Tomonorib18485e2009-11-12 00:03:28 +0900115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 return 1;
117}
118__setup("swiotlb=", setup_io_tlb_npages);
119/* make io_tlb_overflow tunable too? */
120
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900121/* Note that this doesn't work with highmem page */
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800122static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
123 volatile void *address)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800124{
FUJITA Tomonori862d1962009-07-10 10:05:02 +0900125 return phys_to_dma(hwdev, virt_to_phys(address));
Ian Campbelle08e1f72008-12-16 12:17:30 -0800126}
127
FUJITA Tomonoriad32e8c2009-11-10 19:46:19 +0900128void swiotlb_print_info(void)
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800129{
FUJITA Tomonoriad32e8c2009-11-10 19:46:19 +0900130 unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800131 phys_addr_t pstart, pend;
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800132
133 pstart = virt_to_phys(io_tlb_start);
134 pend = virt_to_phys(io_tlb_end);
135
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800136 printk(KERN_INFO "Placing %luMB software IO TLB between %p - %p\n",
137 bytes >> 20, io_tlb_start, io_tlb_end);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800138 printk(KERN_INFO "software IO TLB at phys %#llx - %#llx\n",
139 (unsigned long long)pstart,
140 (unsigned long long)pend);
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800141}
142
FUJITA Tomonoriabbceff2010-05-10 15:15:12 -0400143void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
Jan Beulich563aaf02007-02-05 18:51:25 -0800145 unsigned long i, bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146
FUJITA Tomonoriabbceff2010-05-10 15:15:12 -0400147 bytes = nslabs << IO_TLB_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
FUJITA Tomonoriabbceff2010-05-10 15:15:12 -0400149 io_tlb_nslabs = nslabs;
150 io_tlb_start = tlb;
Jan Beulich563aaf02007-02-05 18:51:25 -0800151 io_tlb_end = io_tlb_start + bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
153 /*
154 * Allocate and initialize the free list array. This array is used
155 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
156 * between io_tlb_start and io_tlb_end.
157 */
158 io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
Tony Luck25667d62007-03-06 13:31:45 -0800159 for (i = 0; i < io_tlb_nslabs; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
161 io_tlb_index = 0;
Becky Brucebc40ac62008-12-22 10:26:08 -0800162 io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164 /*
165 * Get the overflow emergency buffer
166 */
167 io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
Jan Beulich563aaf02007-02-05 18:51:25 -0800168 if (!io_tlb_overflow_buffer)
169 panic("Cannot allocate SWIOTLB overflow buffer!\n");
FUJITA Tomonoriad32e8c2009-11-10 19:46:19 +0900170 if (verbose)
171 swiotlb_print_info();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172}
173
FUJITA Tomonoriabbceff2010-05-10 15:15:12 -0400174/*
175 * Statically reserve bounce buffer space and initialize bounce buffer data
176 * structures for the software IO TLB used to implement the DMA API.
177 */
178void __init
179swiotlb_init_with_default_size(size_t default_size, int verbose)
180{
181 unsigned long bytes;
182
183 if (!io_tlb_nslabs) {
184 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
185 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
186 }
187
188 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
189
190 /*
191 * Get IO TLB memory from the low pages
192 */
193 io_tlb_start = alloc_bootmem_low_pages(bytes);
194 if (!io_tlb_start)
195 panic("Cannot allocate SWIOTLB buffer");
196
197 swiotlb_init_with_tbl(io_tlb_start, io_tlb_nslabs, verbose);
198}
199
Jan Beulich563aaf02007-02-05 18:51:25 -0800200void __init
FUJITA Tomonoriad32e8c2009-11-10 19:46:19 +0900201swiotlb_init(int verbose)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202{
FUJITA Tomonoriad32e8c2009-11-10 19:46:19 +0900203 swiotlb_init_with_default_size(64 * (1<<20), verbose); /* default to 64MB */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204}
205
Alex Williamson0b9afed2005-09-06 11:20:49 -0600206/*
207 * Systems with larger DMA zones (those that don't support ISA) can
208 * initialize the swiotlb later using the slab allocator if needed.
209 * This should be just like above, but with some error catching.
210 */
211int
Jan Beulich563aaf02007-02-05 18:51:25 -0800212swiotlb_late_init_with_default_size(size_t default_size)
Alex Williamson0b9afed2005-09-06 11:20:49 -0600213{
Jan Beulich563aaf02007-02-05 18:51:25 -0800214 unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600215 unsigned int order;
216
217 if (!io_tlb_nslabs) {
218 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
219 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
220 }
221
222 /*
223 * Get IO TLB memory from the low pages
224 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800225 order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600226 io_tlb_nslabs = SLABS_PER_PAGE << order;
Jan Beulich563aaf02007-02-05 18:51:25 -0800227 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600228
229 while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
FUJITA Tomonoribb521962009-07-10 10:04:51 +0900230 io_tlb_start = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
231 order);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600232 if (io_tlb_start)
233 break;
234 order--;
235 }
236
237 if (!io_tlb_start)
238 goto cleanup1;
239
Jan Beulich563aaf02007-02-05 18:51:25 -0800240 if (order != get_order(bytes)) {
Alex Williamson0b9afed2005-09-06 11:20:49 -0600241 printk(KERN_WARNING "Warning: only able to allocate %ld MB "
242 "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
243 io_tlb_nslabs = SLABS_PER_PAGE << order;
Jan Beulich563aaf02007-02-05 18:51:25 -0800244 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600245 }
Jan Beulich563aaf02007-02-05 18:51:25 -0800246 io_tlb_end = io_tlb_start + bytes;
247 memset(io_tlb_start, 0, bytes);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600248
249 /*
250 * Allocate and initialize the free list array. This array is used
251 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
252 * between io_tlb_start and io_tlb_end.
253 */
254 io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
255 get_order(io_tlb_nslabs * sizeof(int)));
256 if (!io_tlb_list)
257 goto cleanup2;
258
259 for (i = 0; i < io_tlb_nslabs; i++)
260 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
261 io_tlb_index = 0;
262
Becky Brucebc40ac62008-12-22 10:26:08 -0800263 io_tlb_orig_addr = (phys_addr_t *)
264 __get_free_pages(GFP_KERNEL,
265 get_order(io_tlb_nslabs *
266 sizeof(phys_addr_t)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600267 if (!io_tlb_orig_addr)
268 goto cleanup3;
269
Becky Brucebc40ac62008-12-22 10:26:08 -0800270 memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600271
272 /*
273 * Get the overflow emergency buffer
274 */
275 io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
276 get_order(io_tlb_overflow));
277 if (!io_tlb_overflow_buffer)
278 goto cleanup4;
279
FUJITA Tomonoriad32e8c2009-11-10 19:46:19 +0900280 swiotlb_print_info();
Alex Williamson0b9afed2005-09-06 11:20:49 -0600281
FUJITA Tomonori5740afd2009-11-10 19:46:18 +0900282 late_alloc = 1;
283
Alex Williamson0b9afed2005-09-06 11:20:49 -0600284 return 0;
285
286cleanup4:
Becky Brucebc40ac62008-12-22 10:26:08 -0800287 free_pages((unsigned long)io_tlb_orig_addr,
288 get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600289 io_tlb_orig_addr = NULL;
290cleanup3:
Tony Luck25667d62007-03-06 13:31:45 -0800291 free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
292 sizeof(int)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600293 io_tlb_list = NULL;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600294cleanup2:
Jan Beulich563aaf02007-02-05 18:51:25 -0800295 io_tlb_end = NULL;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600296 free_pages((unsigned long)io_tlb_start, order);
297 io_tlb_start = NULL;
298cleanup1:
299 io_tlb_nslabs = req_nslabs;
300 return -ENOMEM;
301}
302
FUJITA Tomonori5740afd2009-11-10 19:46:18 +0900303void __init swiotlb_free(void)
304{
305 if (!io_tlb_overflow_buffer)
306 return;
307
308 if (late_alloc) {
309 free_pages((unsigned long)io_tlb_overflow_buffer,
310 get_order(io_tlb_overflow));
311 free_pages((unsigned long)io_tlb_orig_addr,
312 get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
313 free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
314 sizeof(int)));
315 free_pages((unsigned long)io_tlb_start,
316 get_order(io_tlb_nslabs << IO_TLB_SHIFT));
317 } else {
318 free_bootmem_late(__pa(io_tlb_overflow_buffer),
319 io_tlb_overflow);
320 free_bootmem_late(__pa(io_tlb_orig_addr),
321 io_tlb_nslabs * sizeof(phys_addr_t));
322 free_bootmem_late(__pa(io_tlb_list),
323 io_tlb_nslabs * sizeof(int));
324 free_bootmem_late(__pa(io_tlb_start),
325 io_tlb_nslabs << IO_TLB_SHIFT);
326 }
327}
328
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900329static int is_swiotlb_buffer(phys_addr_t paddr)
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900330{
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900331 return paddr >= virt_to_phys(io_tlb_start) &&
332 paddr < virt_to_phys(io_tlb_end);
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900333}
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335/*
Becky Brucefb05a372008-12-22 10:26:09 -0800336 * Bounce: copy the swiotlb buffer back to the original dma location
337 */
338static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
339 enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340{
Becky Brucefb05a372008-12-22 10:26:09 -0800341 unsigned long pfn = PFN_DOWN(phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
Becky Brucefb05a372008-12-22 10:26:09 -0800343 if (PageHighMem(pfn_to_page(pfn))) {
344 /* The buffer does not have a mapping. Map it in and copy */
345 unsigned int offset = phys & ~PAGE_MASK;
346 char *buffer;
347 unsigned int sz = 0;
348 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349
Becky Brucefb05a372008-12-22 10:26:09 -0800350 while (size) {
Becky Bruce67131ad2009-04-08 09:09:16 -0500351 sz = min_t(size_t, PAGE_SIZE - offset, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Becky Brucefb05a372008-12-22 10:26:09 -0800353 local_irq_save(flags);
354 buffer = kmap_atomic(pfn_to_page(pfn),
355 KM_BOUNCE_READ);
356 if (dir == DMA_TO_DEVICE)
357 memcpy(dma_addr, buffer + offset, sz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 else
Becky Brucefb05a372008-12-22 10:26:09 -0800359 memcpy(buffer + offset, dma_addr, sz);
360 kunmap_atomic(buffer, KM_BOUNCE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 local_irq_restore(flags);
Becky Brucefb05a372008-12-22 10:26:09 -0800362
363 size -= sz;
364 pfn++;
365 dma_addr += sz;
366 offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 }
368 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 if (dir == DMA_TO_DEVICE)
Becky Brucefb05a372008-12-22 10:26:09 -0800370 memcpy(dma_addr, phys_to_virt(phys), size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 else
Becky Brucefb05a372008-12-22 10:26:09 -0800372 memcpy(phys_to_virt(phys), dma_addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 }
374}
375
FUJITA Tomonorieb605a52010-05-10 15:14:54 -0400376void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
377 phys_addr_t phys, size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378{
379 unsigned long flags;
380 char *dma_addr;
381 unsigned int nslots, stride, index, wrap;
382 int i;
FUJITA Tomonori681cc5c2008-02-04 22:28:16 -0800383 unsigned long mask;
384 unsigned long offset_slots;
385 unsigned long max_slots;
386
387 mask = dma_get_seg_boundary(hwdev);
FUJITA Tomonori681cc5c2008-02-04 22:28:16 -0800388
FUJITA Tomonorieb605a52010-05-10 15:14:54 -0400389 tbl_dma_addr &= mask;
390
391 offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
Ian Campbella5ddde4a2008-12-16 12:17:29 -0800392
393 /*
394 * Carefully handle integer overflow which can occur when mask == ~0UL.
395 */
Jan Beulichb15a38912008-03-13 09:13:30 +0000396 max_slots = mask + 1
397 ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
398 : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400 /*
401 * For mappings greater than a page, we limit the stride (and
402 * hence alignment) to a page size.
403 */
404 nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
405 if (size > PAGE_SIZE)
406 stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
407 else
408 stride = 1;
409
Eric Sesterhenn34814542006-03-24 18:47:11 +0100410 BUG_ON(!nslots);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
412 /*
413 * Find suitable number of IO TLB entries size that will fit this
414 * request and allocate a buffer from that IO TLB pool.
415 */
416 spin_lock_irqsave(&io_tlb_lock, flags);
Andrew Mortona7133a12008-04-29 00:59:36 -0700417 index = ALIGN(io_tlb_index, stride);
418 if (index >= io_tlb_nslabs)
419 index = 0;
420 wrap = index;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421
Andrew Mortona7133a12008-04-29 00:59:36 -0700422 do {
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700423 while (iommu_is_span_boundary(index, nslots, offset_slots,
424 max_slots)) {
Jan Beulichb15a38912008-03-13 09:13:30 +0000425 index += stride;
426 if (index >= io_tlb_nslabs)
427 index = 0;
Andrew Mortona7133a12008-04-29 00:59:36 -0700428 if (index == wrap)
429 goto not_found;
430 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
Andrew Mortona7133a12008-04-29 00:59:36 -0700432 /*
433 * If we find a slot that indicates we have 'nslots' number of
434 * contiguous buffers, we allocate the buffers from that slot
435 * and mark the entries as '0' indicating unavailable.
436 */
437 if (io_tlb_list[index] >= nslots) {
438 int count = 0;
439
440 for (i = index; i < (int) (index + nslots); i++)
441 io_tlb_list[i] = 0;
442 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
443 io_tlb_list[i] = ++count;
444 dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
445
446 /*
447 * Update the indices to avoid searching in the next
448 * round.
449 */
450 io_tlb_index = ((index + nslots) < io_tlb_nslabs
451 ? (index + nslots) : 0);
452
453 goto found;
454 }
455 index += stride;
456 if (index >= io_tlb_nslabs)
457 index = 0;
458 } while (index != wrap);
459
460not_found:
461 spin_unlock_irqrestore(&io_tlb_lock, flags);
462 return NULL;
463found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 spin_unlock_irqrestore(&io_tlb_lock, flags);
465
466 /*
467 * Save away the mapping from the original address to the DMA address.
468 * This is needed when we sync the memory. Then we sync the buffer if
469 * needed.
470 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800471 for (i = 0; i < nslots; i++)
472 io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
Becky Brucefb05a372008-12-22 10:26:09 -0800474 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
476 return dma_addr;
477}
478
479/*
FUJITA Tomonorieb605a52010-05-10 15:14:54 -0400480 * Allocates bounce buffer and returns its kernel virtual address.
481 */
482
483static void *
484map_single(struct device *hwdev, phys_addr_t phys, size_t size, int dir)
485{
486 dma_addr_t start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start);
487
488 return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir);
489}
490
491/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 * dma_addr is the kernel virtual address of the bounce buffer to unmap.
493 */
494static void
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500495do_unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496{
497 unsigned long flags;
498 int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
499 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
Becky Brucebc40ac62008-12-22 10:26:08 -0800500 phys_addr_t phys = io_tlb_orig_addr[index];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
502 /*
503 * First, sync the memory before unmapping the entry
504 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800505 if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
Becky Brucefb05a372008-12-22 10:26:09 -0800506 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507
508 /*
509 * Return the buffer to the free list by setting the corresponding
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200510 * entries to indicate the number of contiguous entries available.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 * While returning the entries to the free list, we merge the entries
512 * with slots below and above the pool being returned.
513 */
514 spin_lock_irqsave(&io_tlb_lock, flags);
515 {
516 count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
517 io_tlb_list[index + nslots] : 0);
518 /*
519 * Step 1: return the slots to the free list, merging the
520 * slots with superceeding slots
521 */
522 for (i = index + nslots - 1; i >= index; i--)
523 io_tlb_list[i] = ++count;
524 /*
525 * Step 2: merge the returned slots with the preceding slots,
526 * if available (non zero)
527 */
528 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
529 io_tlb_list[i] = ++count;
530 }
531 spin_unlock_irqrestore(&io_tlb_lock, flags);
532}
533
534static void
John W. Linvillede69e0f2005-09-29 14:44:57 -0700535sync_single(struct device *hwdev, char *dma_addr, size_t size,
536 int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537{
Becky Brucebc40ac62008-12-22 10:26:08 -0800538 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
539 phys_addr_t phys = io_tlb_orig_addr[index];
540
541 phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
Keir Fraserdf336d12007-07-21 04:37:24 -0700542
John W. Linvillede69e0f2005-09-29 14:44:57 -0700543 switch (target) {
544 case SYNC_FOR_CPU:
545 if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
Becky Brucefb05a372008-12-22 10:26:09 -0800546 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
Eric Sesterhenn34814542006-03-24 18:47:11 +0100547 else
548 BUG_ON(dir != DMA_TO_DEVICE);
John W. Linvillede69e0f2005-09-29 14:44:57 -0700549 break;
550 case SYNC_FOR_DEVICE:
551 if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
Becky Brucefb05a372008-12-22 10:26:09 -0800552 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
Eric Sesterhenn34814542006-03-24 18:47:11 +0100553 else
554 BUG_ON(dir != DMA_FROM_DEVICE);
John W. Linvillede69e0f2005-09-29 14:44:57 -0700555 break;
556 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 BUG();
John W. Linvillede69e0f2005-09-29 14:44:57 -0700558 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559}
560
561void *
562swiotlb_alloc_coherent(struct device *hwdev, size_t size,
Al Viro06a54492005-10-21 03:21:03 -0400563 dma_addr_t *dma_handle, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564{
Jan Beulich563aaf02007-02-05 18:51:25 -0800565 dma_addr_t dev_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 void *ret;
567 int order = get_order(size);
Yang Hongyang284901a2009-04-06 19:01:15 -0700568 u64 dma_mask = DMA_BIT_MASK(32);
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900569
570 if (hwdev && hwdev->coherent_dma_mask)
571 dma_mask = hwdev->coherent_dma_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572
Tony Luck25667d62007-03-06 13:31:45 -0800573 ret = (void *)__get_free_pages(flags, order);
Jan Beulichac2b3e62009-12-15 16:47:43 -0800574 if (ret && swiotlb_virt_to_bus(hwdev, ret) + size - 1 > dma_mask) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 /*
576 * The allocated memory isn't reachable by the device.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 */
578 free_pages((unsigned long) ret, order);
579 ret = NULL;
580 }
581 if (!ret) {
582 /*
583 * We are either out of memory or the device can't DMA
Becky Bruceceb5ac32009-04-08 09:09:15 -0500584 * to GFP_DMA memory; fall back on map_single(), which
585 * will grab memory from the lowest available address range.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800587 ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
FUJITA Tomonori9dfda122008-09-08 18:53:48 +0900588 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 }
591
592 memset(ret, 0, size);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800593 dev_addr = swiotlb_virt_to_bus(hwdev, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
595 /* Confirm address can be DMA'd by device */
Jan Beulichac2b3e62009-12-15 16:47:43 -0800596 if (dev_addr + size - 1 > dma_mask) {
Jan Beulich563aaf02007-02-05 18:51:25 -0800597 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900598 (unsigned long long)dma_mask,
Jan Beulich563aaf02007-02-05 18:51:25 -0800599 (unsigned long long)dev_addr);
FUJITA Tomonoria2b89b52008-10-23 18:42:03 +0900600
601 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500602 do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
FUJITA Tomonoria2b89b52008-10-23 18:42:03 +0900603 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 }
605 *dma_handle = dev_addr;
606 return ret;
607}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900608EXPORT_SYMBOL(swiotlb_alloc_coherent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
610void
611swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900612 dma_addr_t dev_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613{
FUJITA Tomonori862d1962009-07-10 10:05:02 +0900614 phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900615
David Brownellaa248862007-08-10 13:10:27 -0700616 WARN_ON(irqs_disabled());
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900617 if (!is_swiotlb_buffer(paddr))
618 free_pages((unsigned long)vaddr, get_order(size));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 else
620 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500621 do_unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900623EXPORT_SYMBOL(swiotlb_free_coherent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
625static void
626swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
627{
628 /*
629 * Ran out of IOMMU space for this operation. This is very bad.
630 * Unfortunately the drivers cannot handle this operation properly.
Tony Luck17e5ad62005-09-29 15:52:13 -0700631 * unless they check for dma_mapping_error (most don't)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 * When the mapping is small enough return a static buffer to limit
633 * the damage, or panic when the transfer is too big.
634 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800635 printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
Kay Sievers94b32482009-01-06 10:44:37 -0800636 "device %s\n", size, dev ? dev_name(dev) : "?");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637
Casey Dahlinc7084b32009-08-20 16:27:56 -0700638 if (size <= io_tlb_overflow || !do_panic)
639 return;
640
641 if (dir == DMA_BIDIRECTIONAL)
642 panic("DMA: Random memory could be DMA accessed\n");
643 if (dir == DMA_FROM_DEVICE)
644 panic("DMA: Random memory could be DMA written\n");
645 if (dir == DMA_TO_DEVICE)
646 panic("DMA: Random memory could be DMA read\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647}
648
649/*
650 * Map a single buffer of the indicated size for DMA in streaming mode. The
Tony Luck17e5ad62005-09-29 15:52:13 -0700651 * physical address to use is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 *
653 * Once the device is given the dma address, the device owns this memory until
Becky Bruceceb5ac32009-04-08 09:09:15 -0500654 * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900656dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
657 unsigned long offset, size_t size,
658 enum dma_data_direction dir,
659 struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660{
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900661 phys_addr_t phys = page_to_phys(page) + offset;
FUJITA Tomonori862d1962009-07-10 10:05:02 +0900662 dma_addr_t dev_addr = phys_to_dma(dev, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 void *map;
664
Eric Sesterhenn34814542006-03-24 18:47:11 +0100665 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 /*
Becky Bruceceb5ac32009-04-08 09:09:15 -0500667 * If the address happens to be in the device's DMA window,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 * we can safely return the device addr and not worry about bounce
669 * buffering it.
670 */
FUJITA Tomonorib9394642009-07-10 10:04:58 +0900671 if (dma_capable(dev, dev_addr, size) && !swiotlb_force)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 return dev_addr;
673
674 /*
675 * Oh well, have to allocate and map a bounce buffer.
676 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900677 map = map_single(dev, phys, size, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 if (!map) {
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900679 swiotlb_full(dev, size, dir, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 map = io_tlb_overflow_buffer;
681 }
682
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900683 dev_addr = swiotlb_virt_to_bus(dev, map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
685 /*
686 * Ensure that the address returned is DMA'ble
687 */
FUJITA Tomonorib9394642009-07-10 10:04:58 +0900688 if (!dma_capable(dev, dev_addr, size))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 panic("map_single: bounce buffer is not DMA'ble");
690
691 return dev_addr;
692}
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900693EXPORT_SYMBOL_GPL(swiotlb_map_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
695/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 * Unmap a single streaming mode DMA translation. The dma_addr and size must
Becky Bruceceb5ac32009-04-08 09:09:15 -0500697 * match what was provided for in a previous swiotlb_map_page call. All
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 * other usages are undefined.
699 *
700 * After this call, reads by the cpu to the buffer are guaranteed to see
701 * whatever the device wrote there.
702 */
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500703static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
704 size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705{
FUJITA Tomonori862d1962009-07-10 10:05:02 +0900706 phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707
Eric Sesterhenn34814542006-03-24 18:47:11 +0100708 BUG_ON(dir == DMA_NONE);
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500709
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900710 if (is_swiotlb_buffer(paddr)) {
711 do_unmap_single(hwdev, phys_to_virt(paddr), size, dir);
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500712 return;
713 }
714
715 if (dir != DMA_FROM_DEVICE)
716 return;
717
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900718 /*
719 * phys_to_virt doesn't work with hihgmem page but we could
720 * call dma_mark_clean() with hihgmem page here. However, we
721 * are fine since dma_mark_clean() is null on POWERPC. We can
722 * make dma_mark_clean() take a physical address if necessary.
723 */
724 dma_mark_clean(phys_to_virt(paddr), size);
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500725}
726
727void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
728 size_t size, enum dma_data_direction dir,
729 struct dma_attrs *attrs)
730{
731 unmap_single(hwdev, dev_addr, size, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732}
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900733EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735/*
736 * Make physical memory consistent for a single streaming mode DMA translation
737 * after a transfer.
738 *
Becky Bruceceb5ac32009-04-08 09:09:15 -0500739 * If you perform a swiotlb_map_page() but wish to interrogate the buffer
Tony Luck17e5ad62005-09-29 15:52:13 -0700740 * using the cpu, yet do not wish to teardown the dma mapping, you must
741 * call this function before doing so. At the next point you give the dma
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 * address back to the card, you must first perform a
743 * swiotlb_dma_sync_for_device, and then the device again owns the buffer
744 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800745static void
John W. Linville8270f3f2005-09-29 14:43:32 -0700746swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700747 size_t size, int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748{
FUJITA Tomonori862d1962009-07-10 10:05:02 +0900749 phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750
Eric Sesterhenn34814542006-03-24 18:47:11 +0100751 BUG_ON(dir == DMA_NONE);
Becky Bruce380d6872009-04-08 09:09:20 -0500752
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900753 if (is_swiotlb_buffer(paddr)) {
754 sync_single(hwdev, phys_to_virt(paddr), size, dir, target);
Becky Bruce380d6872009-04-08 09:09:20 -0500755 return;
756 }
757
758 if (dir != DMA_FROM_DEVICE)
759 return;
760
FUJITA Tomonori02ca6462009-07-23 11:18:49 +0900761 dma_mark_clean(phys_to_virt(paddr), size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762}
763
764void
John W. Linville8270f3f2005-09-29 14:43:32 -0700765swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900766 size_t size, enum dma_data_direction dir)
John W. Linville8270f3f2005-09-29 14:43:32 -0700767{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700768 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
John W. Linville8270f3f2005-09-29 14:43:32 -0700769}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900770EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
John W. Linville8270f3f2005-09-29 14:43:32 -0700771
772void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900774 size_t size, enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700776 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900778EXPORT_SYMBOL(swiotlb_sync_single_for_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
780/*
781 * Map a set of buffers described by scatterlist in streaming mode for DMA.
Becky Bruceceb5ac32009-04-08 09:09:15 -0500782 * This is the scatter-gather version of the above swiotlb_map_page
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 * interface. Here the scatter gather list elements are each tagged with the
784 * appropriate dma address and length. They are obtained via
785 * sg_dma_{address,length}(SG).
786 *
787 * NOTE: An implementation may be able to use a smaller number of
788 * DMA address/length pairs than there are SG table elements.
789 * (for example via virtual mapping capabilities)
790 * The routine returns the number of addr/length pairs actually
791 * used, at most nents.
792 *
Becky Bruceceb5ac32009-04-08 09:09:15 -0500793 * Device ownership issues as mentioned above for swiotlb_map_page are the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794 * same here.
795 */
796int
Arthur Kepner309df0c2008-04-29 01:00:32 -0700797swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900798 enum dma_data_direction dir, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200800 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 int i;
802
Eric Sesterhenn34814542006-03-24 18:47:11 +0100803 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804
Jens Axboedbfd49f2007-05-11 14:56:18 +0200805 for_each_sg(sgl, sg, nelems, i) {
Ian Campbell961d7d02009-01-09 18:32:10 +0000806 phys_addr_t paddr = sg_phys(sg);
FUJITA Tomonori862d1962009-07-10 10:05:02 +0900807 dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
Becky Brucebc40ac62008-12-22 10:26:08 -0800808
FUJITA Tomonoricf56e3f2009-07-10 10:04:52 +0900809 if (swiotlb_force ||
FUJITA Tomonorib9394642009-07-10 10:04:58 +0900810 !dma_capable(hwdev, dev_addr, sg->length)) {
Becky Brucebc40ac62008-12-22 10:26:08 -0800811 void *map = map_single(hwdev, sg_phys(sg),
812 sg->length, dir);
Andi Kleen7e870232005-12-20 14:45:19 +0100813 if (!map) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 /* Don't panic here, we expect map_sg users
815 to do proper error handling. */
816 swiotlb_full(hwdev, sg->length, dir, 0);
Arthur Kepner309df0c2008-04-29 01:00:32 -0700817 swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
818 attrs);
Jens Axboedbfd49f2007-05-11 14:56:18 +0200819 sgl[0].dma_length = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820 return 0;
821 }
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800822 sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 } else
824 sg->dma_address = dev_addr;
825 sg->dma_length = sg->length;
826 }
827 return nelems;
828}
Arthur Kepner309df0c2008-04-29 01:00:32 -0700829EXPORT_SYMBOL(swiotlb_map_sg_attrs);
830
831int
832swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
833 int dir)
834{
835 return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
836}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900837EXPORT_SYMBOL(swiotlb_map_sg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838
839/*
840 * Unmap a set of streaming mode DMA translations. Again, cpu read rules
Becky Bruceceb5ac32009-04-08 09:09:15 -0500841 * concerning calls here are the same as for swiotlb_unmap_page() above.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 */
843void
Arthur Kepner309df0c2008-04-29 01:00:32 -0700844swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900845 int nelems, enum dma_data_direction dir, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200847 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 int i;
849
Eric Sesterhenn34814542006-03-24 18:47:11 +0100850 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
Becky Bruce7fcebbd2009-04-08 09:09:19 -0500852 for_each_sg(sgl, sg, nelems, i)
853 unmap_single(hwdev, sg->dma_address, sg->dma_length, dir);
854
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855}
Arthur Kepner309df0c2008-04-29 01:00:32 -0700856EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
857
858void
859swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
860 int dir)
861{
862 return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
863}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900864EXPORT_SYMBOL(swiotlb_unmap_sg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
866/*
867 * Make physical memory consistent for a set of streaming mode DMA translations
868 * after a transfer.
869 *
870 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
871 * and usage.
872 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800873static void
Jens Axboedbfd49f2007-05-11 14:56:18 +0200874swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700875 int nelems, int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200877 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 int i;
879
Becky Bruce380d6872009-04-08 09:09:20 -0500880 for_each_sg(sgl, sg, nelems, i)
881 swiotlb_sync_single(hwdev, sg->dma_address,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700882 sg->dma_length, dir, target);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883}
884
885void
John W. Linville8270f3f2005-09-29 14:43:32 -0700886swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900887 int nelems, enum dma_data_direction dir)
John W. Linville8270f3f2005-09-29 14:43:32 -0700888{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700889 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
John W. Linville8270f3f2005-09-29 14:43:32 -0700890}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900891EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
John W. Linville8270f3f2005-09-29 14:43:32 -0700892
893void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900895 int nelems, enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700897 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900899EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
901int
FUJITA Tomonori8d8bb392008-07-25 19:44:49 -0700902swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800904 return (dma_addr == swiotlb_virt_to_bus(hwdev, io_tlb_overflow_buffer));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900906EXPORT_SYMBOL(swiotlb_dma_mapping_error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907
908/*
Tony Luck17e5ad62005-09-29 15:52:13 -0700909 * Return whether the given device DMA address mask can be supported
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 * properly. For example, if your device can only drive the low 24-bits
Tony Luck17e5ad62005-09-29 15:52:13 -0700911 * during bus mastering, then you would pass 0x00ffffff as the mask to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 * this function.
913 */
914int
Jan Beulich563aaf02007-02-05 18:51:25 -0800915swiotlb_dma_supported(struct device *hwdev, u64 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800917 return swiotlb_virt_to_bus(hwdev, io_tlb_end - 1) <= mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919EXPORT_SYMBOL(swiotlb_dma_supported);