blob: 2b0b5a7d2ced165b1e2b83e2df888c237349f23f [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/*
63 * Used to do a quick range check in swiotlb_unmap_single and
64 * swiotlb_sync_single_*, to see if the memory was in fact allocated by this
65 * 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
Roland Dreier79ff56e2008-12-30 20:18:00 -0800117void * __weak __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
Jeremy Fitzhardinge8c5df162008-12-16 12:17:26 -0800118{
119 return alloc_bootmem_low_pages(size);
120}
121
122void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs)
123{
124 return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
125}
126
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800127dma_addr_t __weak swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800128{
129 return paddr;
130}
131
132phys_addr_t __weak swiotlb_bus_to_phys(dma_addr_t baddr)
133{
134 return baddr;
135}
136
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800137static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
138 volatile void *address)
Ian Campbelle08e1f72008-12-16 12:17:30 -0800139{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800140 return swiotlb_phys_to_bus(hwdev, virt_to_phys(address));
Ian Campbelle08e1f72008-12-16 12:17:30 -0800141}
142
143static void *swiotlb_bus_to_virt(dma_addr_t address)
144{
145 return phys_to_virt(swiotlb_bus_to_phys(address));
146}
147
Ian Campbell0b8698a2009-01-09 18:32:09 +0000148int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
Ian Campbellb81ea272008-12-16 12:17:31 -0800149{
150 return 0;
151}
152
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800153static void swiotlb_print_info(unsigned long bytes)
154{
155 phys_addr_t pstart, pend;
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800156
157 pstart = virt_to_phys(io_tlb_start);
158 pend = virt_to_phys(io_tlb_end);
159
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800160 printk(KERN_INFO "Placing %luMB software IO TLB between %p - %p\n",
161 bytes >> 20, io_tlb_start, io_tlb_end);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800162 printk(KERN_INFO "software IO TLB at phys %#llx - %#llx\n",
163 (unsigned long long)pstart,
164 (unsigned long long)pend);
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800165}
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167/*
168 * Statically reserve bounce buffer space and initialize bounce buffer data
Tony Luck17e5ad62005-09-29 15:52:13 -0700169 * structures for the software IO TLB used to implement the DMA API.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800171void __init
172swiotlb_init_with_default_size(size_t default_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
Jan Beulich563aaf02007-02-05 18:51:25 -0800174 unsigned long i, bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 if (!io_tlb_nslabs) {
Alex Williamsone8579e72005-08-04 13:06:00 -0700177 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
179 }
180
Jan Beulich563aaf02007-02-05 18:51:25 -0800181 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 /*
184 * Get IO TLB memory from the low pages
185 */
Jeremy Fitzhardinge8c5df162008-12-16 12:17:26 -0800186 io_tlb_start = swiotlb_alloc_boot(bytes, io_tlb_nslabs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 if (!io_tlb_start)
188 panic("Cannot allocate SWIOTLB buffer");
Jan Beulich563aaf02007-02-05 18:51:25 -0800189 io_tlb_end = io_tlb_start + bytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
191 /*
192 * Allocate and initialize the free list array. This array is used
193 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
194 * between io_tlb_start and io_tlb_end.
195 */
196 io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
Tony Luck25667d62007-03-06 13:31:45 -0800197 for (i = 0; i < io_tlb_nslabs; i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
199 io_tlb_index = 0;
Becky Brucebc40ac62008-12-22 10:26:08 -0800200 io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 /*
203 * Get the overflow emergency buffer
204 */
205 io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
Jan Beulich563aaf02007-02-05 18:51:25 -0800206 if (!io_tlb_overflow_buffer)
207 panic("Cannot allocate SWIOTLB overflow buffer!\n");
208
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800209 swiotlb_print_info(bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210}
211
Jan Beulich563aaf02007-02-05 18:51:25 -0800212void __init
213swiotlb_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214{
Tony Luck25667d62007-03-06 13:31:45 -0800215 swiotlb_init_with_default_size(64 * (1<<20)); /* default to 64MB */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216}
217
Alex Williamson0b9afed2005-09-06 11:20:49 -0600218/*
219 * Systems with larger DMA zones (those that don't support ISA) can
220 * initialize the swiotlb later using the slab allocator if needed.
221 * This should be just like above, but with some error catching.
222 */
223int
Jan Beulich563aaf02007-02-05 18:51:25 -0800224swiotlb_late_init_with_default_size(size_t default_size)
Alex Williamson0b9afed2005-09-06 11:20:49 -0600225{
Jan Beulich563aaf02007-02-05 18:51:25 -0800226 unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600227 unsigned int order;
228
229 if (!io_tlb_nslabs) {
230 io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
231 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
232 }
233
234 /*
235 * Get IO TLB memory from the low pages
236 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800237 order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600238 io_tlb_nslabs = SLABS_PER_PAGE << order;
Jan Beulich563aaf02007-02-05 18:51:25 -0800239 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600240
241 while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
Jeremy Fitzhardinge8c5df162008-12-16 12:17:26 -0800242 io_tlb_start = swiotlb_alloc(order, io_tlb_nslabs);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600243 if (io_tlb_start)
244 break;
245 order--;
246 }
247
248 if (!io_tlb_start)
249 goto cleanup1;
250
Jan Beulich563aaf02007-02-05 18:51:25 -0800251 if (order != get_order(bytes)) {
Alex Williamson0b9afed2005-09-06 11:20:49 -0600252 printk(KERN_WARNING "Warning: only able to allocate %ld MB "
253 "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
254 io_tlb_nslabs = SLABS_PER_PAGE << order;
Jan Beulich563aaf02007-02-05 18:51:25 -0800255 bytes = io_tlb_nslabs << IO_TLB_SHIFT;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600256 }
Jan Beulich563aaf02007-02-05 18:51:25 -0800257 io_tlb_end = io_tlb_start + bytes;
258 memset(io_tlb_start, 0, bytes);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600259
260 /*
261 * Allocate and initialize the free list array. This array is used
262 * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
263 * between io_tlb_start and io_tlb_end.
264 */
265 io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
266 get_order(io_tlb_nslabs * sizeof(int)));
267 if (!io_tlb_list)
268 goto cleanup2;
269
270 for (i = 0; i < io_tlb_nslabs; i++)
271 io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
272 io_tlb_index = 0;
273
Becky Brucebc40ac62008-12-22 10:26:08 -0800274 io_tlb_orig_addr = (phys_addr_t *)
275 __get_free_pages(GFP_KERNEL,
276 get_order(io_tlb_nslabs *
277 sizeof(phys_addr_t)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600278 if (!io_tlb_orig_addr)
279 goto cleanup3;
280
Becky Brucebc40ac62008-12-22 10:26:08 -0800281 memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600282
283 /*
284 * Get the overflow emergency buffer
285 */
286 io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
287 get_order(io_tlb_overflow));
288 if (!io_tlb_overflow_buffer)
289 goto cleanup4;
290
Ian Campbell2e5b2b82008-12-16 12:17:34 -0800291 swiotlb_print_info(bytes);
Alex Williamson0b9afed2005-09-06 11:20:49 -0600292
293 return 0;
294
295cleanup4:
Becky Brucebc40ac62008-12-22 10:26:08 -0800296 free_pages((unsigned long)io_tlb_orig_addr,
297 get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600298 io_tlb_orig_addr = NULL;
299cleanup3:
Tony Luck25667d62007-03-06 13:31:45 -0800300 free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
301 sizeof(int)));
Alex Williamson0b9afed2005-09-06 11:20:49 -0600302 io_tlb_list = NULL;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600303cleanup2:
Jan Beulich563aaf02007-02-05 18:51:25 -0800304 io_tlb_end = NULL;
Alex Williamson0b9afed2005-09-06 11:20:49 -0600305 free_pages((unsigned long)io_tlb_start, order);
306 io_tlb_start = NULL;
307cleanup1:
308 io_tlb_nslabs = req_nslabs;
309 return -ENOMEM;
310}
311
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800312static int
FUJITA Tomonori27979822008-09-10 01:06:49 +0900313address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314{
FUJITA Tomonori07a2c012008-09-19 02:02:05 +0900315 return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316}
317
Ian Campbell0b8698a2009-01-09 18:32:09 +0000318static inline int range_needs_mapping(phys_addr_t paddr, size_t size)
Ian Campbellb81ea272008-12-16 12:17:31 -0800319{
Ian Campbell0b8698a2009-01-09 18:32:09 +0000320 return swiotlb_force || swiotlb_arch_range_needs_mapping(paddr, size);
Ian Campbellb81ea272008-12-16 12:17:31 -0800321}
322
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900323static int is_swiotlb_buffer(char *addr)
324{
325 return addr >= io_tlb_start && addr < io_tlb_end;
326}
327
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328/*
Becky Brucefb05a372008-12-22 10:26:09 -0800329 * Bounce: copy the swiotlb buffer back to the original dma location
330 */
331static void swiotlb_bounce(phys_addr_t phys, char *dma_addr, size_t size,
332 enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333{
Becky Brucefb05a372008-12-22 10:26:09 -0800334 unsigned long pfn = PFN_DOWN(phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Becky Brucefb05a372008-12-22 10:26:09 -0800336 if (PageHighMem(pfn_to_page(pfn))) {
337 /* The buffer does not have a mapping. Map it in and copy */
338 unsigned int offset = phys & ~PAGE_MASK;
339 char *buffer;
340 unsigned int sz = 0;
341 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
Becky Brucefb05a372008-12-22 10:26:09 -0800343 while (size) {
344 sz = min(PAGE_SIZE - offset, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
Becky Brucefb05a372008-12-22 10:26:09 -0800346 local_irq_save(flags);
347 buffer = kmap_atomic(pfn_to_page(pfn),
348 KM_BOUNCE_READ);
349 if (dir == DMA_TO_DEVICE)
350 memcpy(dma_addr, buffer + offset, sz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 else
Becky Brucefb05a372008-12-22 10:26:09 -0800352 memcpy(buffer + offset, dma_addr, sz);
353 kunmap_atomic(buffer, KM_BOUNCE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 local_irq_restore(flags);
Becky Brucefb05a372008-12-22 10:26:09 -0800355
356 size -= sz;
357 pfn++;
358 dma_addr += sz;
359 offset = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 }
361 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 if (dir == DMA_TO_DEVICE)
Becky Brucefb05a372008-12-22 10:26:09 -0800363 memcpy(dma_addr, phys_to_virt(phys), size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 else
Becky Brucefb05a372008-12-22 10:26:09 -0800365 memcpy(phys_to_virt(phys), dma_addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 }
367}
368
369/*
370 * Allocates bounce buffer and returns its kernel virtual address.
371 */
372static void *
Becky Brucebc40ac62008-12-22 10:26:08 -0800373map_single(struct device *hwdev, phys_addr_t phys, size_t size, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374{
375 unsigned long flags;
376 char *dma_addr;
377 unsigned int nslots, stride, index, wrap;
378 int i;
FUJITA Tomonori681cc5c2008-02-04 22:28:16 -0800379 unsigned long start_dma_addr;
380 unsigned long mask;
381 unsigned long offset_slots;
382 unsigned long max_slots;
383
384 mask = dma_get_seg_boundary(hwdev);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800385 start_dma_addr = swiotlb_virt_to_bus(hwdev, io_tlb_start) & mask;
FUJITA Tomonori681cc5c2008-02-04 22:28:16 -0800386
387 offset_slots = ALIGN(start_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
Ian Campbella5ddde42008-12-16 12:17:29 -0800388
389 /*
390 * Carefully handle integer overflow which can occur when mask == ~0UL.
391 */
Jan Beulichb15a3892008-03-13 09:13:30 +0000392 max_slots = mask + 1
393 ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
394 : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
396 /*
397 * For mappings greater than a page, we limit the stride (and
398 * hence alignment) to a page size.
399 */
400 nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
401 if (size > PAGE_SIZE)
402 stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
403 else
404 stride = 1;
405
Eric Sesterhenn34814542006-03-24 18:47:11 +0100406 BUG_ON(!nslots);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
408 /*
409 * Find suitable number of IO TLB entries size that will fit this
410 * request and allocate a buffer from that IO TLB pool.
411 */
412 spin_lock_irqsave(&io_tlb_lock, flags);
Andrew Mortona7133a12008-04-29 00:59:36 -0700413 index = ALIGN(io_tlb_index, stride);
414 if (index >= io_tlb_nslabs)
415 index = 0;
416 wrap = index;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
Andrew Mortona7133a12008-04-29 00:59:36 -0700418 do {
FUJITA Tomonoria8522502008-04-29 00:59:36 -0700419 while (iommu_is_span_boundary(index, nslots, offset_slots,
420 max_slots)) {
Jan Beulichb15a3892008-03-13 09:13:30 +0000421 index += stride;
422 if (index >= io_tlb_nslabs)
423 index = 0;
Andrew Mortona7133a12008-04-29 00:59:36 -0700424 if (index == wrap)
425 goto not_found;
426 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
Andrew Mortona7133a12008-04-29 00:59:36 -0700428 /*
429 * If we find a slot that indicates we have 'nslots' number of
430 * contiguous buffers, we allocate the buffers from that slot
431 * and mark the entries as '0' indicating unavailable.
432 */
433 if (io_tlb_list[index] >= nslots) {
434 int count = 0;
435
436 for (i = index; i < (int) (index + nslots); i++)
437 io_tlb_list[i] = 0;
438 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
439 io_tlb_list[i] = ++count;
440 dma_addr = io_tlb_start + (index << IO_TLB_SHIFT);
441
442 /*
443 * Update the indices to avoid searching in the next
444 * round.
445 */
446 io_tlb_index = ((index + nslots) < io_tlb_nslabs
447 ? (index + nslots) : 0);
448
449 goto found;
450 }
451 index += stride;
452 if (index >= io_tlb_nslabs)
453 index = 0;
454 } while (index != wrap);
455
456not_found:
457 spin_unlock_irqrestore(&io_tlb_lock, flags);
458 return NULL;
459found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 spin_unlock_irqrestore(&io_tlb_lock, flags);
461
462 /*
463 * Save away the mapping from the original address to the DMA address.
464 * This is needed when we sync the memory. Then we sync the buffer if
465 * needed.
466 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800467 for (i = 0; i < nslots; i++)
468 io_tlb_orig_addr[index+i] = phys + (i << IO_TLB_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
Becky Brucefb05a372008-12-22 10:26:09 -0800470 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472 return dma_addr;
473}
474
475/*
476 * dma_addr is the kernel virtual address of the bounce buffer to unmap.
477 */
478static void
479unmap_single(struct device *hwdev, char *dma_addr, size_t size, int dir)
480{
481 unsigned long flags;
482 int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
483 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
Becky Brucebc40ac62008-12-22 10:26:08 -0800484 phys_addr_t phys = io_tlb_orig_addr[index];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
486 /*
487 * First, sync the memory before unmapping the entry
488 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800489 if (phys && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
Becky Brucefb05a372008-12-22 10:26:09 -0800490 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
492 /*
493 * Return the buffer to the free list by setting the corresponding
494 * entries to indicate the number of contigous entries available.
495 * While returning the entries to the free list, we merge the entries
496 * with slots below and above the pool being returned.
497 */
498 spin_lock_irqsave(&io_tlb_lock, flags);
499 {
500 count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
501 io_tlb_list[index + nslots] : 0);
502 /*
503 * Step 1: return the slots to the free list, merging the
504 * slots with superceeding slots
505 */
506 for (i = index + nslots - 1; i >= index; i--)
507 io_tlb_list[i] = ++count;
508 /*
509 * Step 2: merge the returned slots with the preceding slots,
510 * if available (non zero)
511 */
512 for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
513 io_tlb_list[i] = ++count;
514 }
515 spin_unlock_irqrestore(&io_tlb_lock, flags);
516}
517
518static void
John W. Linvillede69e0f2005-09-29 14:44:57 -0700519sync_single(struct device *hwdev, char *dma_addr, size_t size,
520 int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521{
Becky Brucebc40ac62008-12-22 10:26:08 -0800522 int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
523 phys_addr_t phys = io_tlb_orig_addr[index];
524
525 phys += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
Keir Fraserdf336d12007-07-21 04:37:24 -0700526
John W. Linvillede69e0f2005-09-29 14:44:57 -0700527 switch (target) {
528 case SYNC_FOR_CPU:
529 if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
Becky Brucefb05a372008-12-22 10:26:09 -0800530 swiotlb_bounce(phys, dma_addr, size, DMA_FROM_DEVICE);
Eric Sesterhenn34814542006-03-24 18:47:11 +0100531 else
532 BUG_ON(dir != DMA_TO_DEVICE);
John W. Linvillede69e0f2005-09-29 14:44:57 -0700533 break;
534 case SYNC_FOR_DEVICE:
535 if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
Becky Brucefb05a372008-12-22 10:26:09 -0800536 swiotlb_bounce(phys, dma_addr, size, DMA_TO_DEVICE);
Eric Sesterhenn34814542006-03-24 18:47:11 +0100537 else
538 BUG_ON(dir != DMA_FROM_DEVICE);
John W. Linvillede69e0f2005-09-29 14:44:57 -0700539 break;
540 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 BUG();
John W. Linvillede69e0f2005-09-29 14:44:57 -0700542 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543}
544
545void *
546swiotlb_alloc_coherent(struct device *hwdev, size_t size,
Al Viro06a54492005-10-21 03:21:03 -0400547 dma_addr_t *dma_handle, gfp_t flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548{
Jan Beulich563aaf02007-02-05 18:51:25 -0800549 dma_addr_t dev_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 void *ret;
551 int order = get_order(size);
Yang Hongyang284901a2009-04-06 19:01:15 -0700552 u64 dma_mask = DMA_BIT_MASK(32);
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900553
554 if (hwdev && hwdev->coherent_dma_mask)
555 dma_mask = hwdev->coherent_dma_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
Tony Luck25667d62007-03-06 13:31:45 -0800557 ret = (void *)__get_free_pages(flags, order);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800558 if (ret &&
559 !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev, ret),
560 size)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 /*
562 * The allocated memory isn't reachable by the device.
563 * Fall back on swiotlb_map_single().
564 */
565 free_pages((unsigned long) ret, order);
566 ret = NULL;
567 }
568 if (!ret) {
569 /*
570 * We are either out of memory or the device can't DMA
571 * to GFP_DMA memory; fall back on
572 * swiotlb_map_single(), which will grab memory from
573 * the lowest available address range.
574 */
Becky Brucebc40ac62008-12-22 10:26:08 -0800575 ret = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
FUJITA Tomonori9dfda122008-09-08 18:53:48 +0900576 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 }
579
580 memset(ret, 0, size);
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800581 dev_addr = swiotlb_virt_to_bus(hwdev, ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
583 /* Confirm address can be DMA'd by device */
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900584 if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
Jan Beulich563aaf02007-02-05 18:51:25 -0800585 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
FUJITA Tomonori1e74f302008-11-17 16:24:34 +0900586 (unsigned long long)dma_mask,
Jan Beulich563aaf02007-02-05 18:51:25 -0800587 (unsigned long long)dev_addr);
FUJITA Tomonoria2b89b52008-10-23 18:42:03 +0900588
589 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
590 unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
591 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 }
593 *dma_handle = dev_addr;
594 return ret;
595}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900596EXPORT_SYMBOL(swiotlb_alloc_coherent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
598void
599swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
600 dma_addr_t dma_handle)
601{
David Brownellaa248862007-08-10 13:10:27 -0700602 WARN_ON(irqs_disabled());
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900603 if (!is_swiotlb_buffer(vaddr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 free_pages((unsigned long) vaddr, get_order(size));
605 else
606 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
FUJITA Tomonori21f6c4d2008-09-08 18:53:49 +0900607 unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900609EXPORT_SYMBOL(swiotlb_free_coherent);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
611static void
612swiotlb_full(struct device *dev, size_t size, int dir, int do_panic)
613{
614 /*
615 * Ran out of IOMMU space for this operation. This is very bad.
616 * Unfortunately the drivers cannot handle this operation properly.
Tony Luck17e5ad62005-09-29 15:52:13 -0700617 * unless they check for dma_mapping_error (most don't)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 * When the mapping is small enough return a static buffer to limit
619 * the damage, or panic when the transfer is too big.
620 */
Jan Beulich563aaf02007-02-05 18:51:25 -0800621 printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
Kay Sievers94b32482009-01-06 10:44:37 -0800622 "device %s\n", size, dev ? dev_name(dev) : "?");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
624 if (size > io_tlb_overflow && do_panic) {
Tony Luck17e5ad62005-09-29 15:52:13 -0700625 if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)
626 panic("DMA: Memory would be corrupted\n");
627 if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
628 panic("DMA: Random memory would be DMAed\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 }
630}
631
632/*
633 * Map a single buffer of the indicated size for DMA in streaming mode. The
Tony Luck17e5ad62005-09-29 15:52:13 -0700634 * physical address to use is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 *
636 * Once the device is given the dma address, the device owns this memory until
637 * either swiotlb_unmap_single or swiotlb_dma_sync_single is performed.
638 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900639dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
640 unsigned long offset, size_t size,
641 enum dma_data_direction dir,
642 struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643{
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900644 phys_addr_t phys = page_to_phys(page) + offset;
645 void *ptr = page_address(page) + offset;
646 dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 void *map;
648
Eric Sesterhenn34814542006-03-24 18:47:11 +0100649 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 /*
651 * If the pointer passed in happens to be in the device's DMA window,
652 * we can safely return the device addr and not worry about bounce
653 * buffering it.
654 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900655 if (!address_needs_mapping(dev, dev_addr, size) &&
Ian Campbell0b8698a2009-01-09 18:32:09 +0000656 !range_needs_mapping(virt_to_phys(ptr), size))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 return dev_addr;
658
659 /*
660 * Oh well, have to allocate and map a bounce buffer.
661 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900662 map = map_single(dev, phys, size, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 if (!map) {
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900664 swiotlb_full(dev, size, dir, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 map = io_tlb_overflow_buffer;
666 }
667
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900668 dev_addr = swiotlb_virt_to_bus(dev, map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669
670 /*
671 * Ensure that the address returned is DMA'ble
672 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900673 if (address_needs_mapping(dev, dev_addr, size))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 panic("map_single: bounce buffer is not DMA'ble");
675
676 return dev_addr;
677}
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900678EXPORT_SYMBOL_GPL(swiotlb_map_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679
680/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 * Unmap a single streaming mode DMA translation. The dma_addr and size must
682 * match what was provided for in a previous swiotlb_map_single call. All
683 * other usages are undefined.
684 *
685 * After this call, reads by the cpu to the buffer are guaranteed to see
686 * whatever the device wrote there.
687 */
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900688void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
689 size_t size, enum dma_data_direction dir,
690 struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691{
Ian Campbelle08e1f72008-12-16 12:17:30 -0800692 char *dma_addr = swiotlb_bus_to_virt(dev_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
Eric Sesterhenn34814542006-03-24 18:47:11 +0100694 BUG_ON(dir == DMA_NONE);
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900695 if (is_swiotlb_buffer(dma_addr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 unmap_single(hwdev, dma_addr, size, dir);
697 else if (dir == DMA_FROM_DEVICE)
Jan Beulichcde14bb2007-02-05 18:46:40 -0800698 dma_mark_clean(dma_addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699}
FUJITA Tomonorif98eee82009-01-05 23:59:03 +0900700EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702/*
703 * Make physical memory consistent for a single streaming mode DMA translation
704 * after a transfer.
705 *
706 * If you perform a swiotlb_map_single() but wish to interrogate the buffer
Tony Luck17e5ad62005-09-29 15:52:13 -0700707 * using the cpu, yet do not wish to teardown the dma mapping, you must
708 * call this function before doing so. At the next point you give the dma
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 * address back to the card, you must first perform a
710 * swiotlb_dma_sync_for_device, and then the device again owns the buffer
711 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800712static void
John W. Linville8270f3f2005-09-29 14:43:32 -0700713swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700714 size_t size, int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715{
Ian Campbelle08e1f72008-12-16 12:17:30 -0800716 char *dma_addr = swiotlb_bus_to_virt(dev_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
Eric Sesterhenn34814542006-03-24 18:47:11 +0100718 BUG_ON(dir == DMA_NONE);
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900719 if (is_swiotlb_buffer(dma_addr))
John W. Linvillede69e0f2005-09-29 14:44:57 -0700720 sync_single(hwdev, dma_addr, size, dir, target);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 else if (dir == DMA_FROM_DEVICE)
Jan Beulichcde14bb2007-02-05 18:46:40 -0800722 dma_mark_clean(dma_addr, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723}
724
725void
John W. Linville8270f3f2005-09-29 14:43:32 -0700726swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900727 size_t size, enum dma_data_direction dir)
John W. Linville8270f3f2005-09-29 14:43:32 -0700728{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700729 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
John W. Linville8270f3f2005-09-29 14:43:32 -0700730}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900731EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
John W. Linville8270f3f2005-09-29 14:43:32 -0700732
733void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900735 size_t size, enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700737 swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900739EXPORT_SYMBOL(swiotlb_sync_single_for_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
741/*
John W. Linville878a97c2005-09-29 14:44:23 -0700742 * Same as above, but for a sub-range of the mapping.
743 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800744static void
John W. Linville878a97c2005-09-29 14:44:23 -0700745swiotlb_sync_single_range(struct device *hwdev, dma_addr_t dev_addr,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700746 unsigned long offset, size_t size,
747 int dir, int target)
John W. Linville878a97c2005-09-29 14:44:23 -0700748{
Ian Campbelle08e1f72008-12-16 12:17:30 -0800749 char *dma_addr = swiotlb_bus_to_virt(dev_addr) + offset;
John W. Linville878a97c2005-09-29 14:44:23 -0700750
Eric Sesterhenn34814542006-03-24 18:47:11 +0100751 BUG_ON(dir == DMA_NONE);
FUJITA Tomonori640aebf2008-09-08 18:53:50 +0900752 if (is_swiotlb_buffer(dma_addr))
John W. Linvillede69e0f2005-09-29 14:44:57 -0700753 sync_single(hwdev, dma_addr, size, dir, target);
John W. Linville878a97c2005-09-29 14:44:23 -0700754 else if (dir == DMA_FROM_DEVICE)
Jan Beulichcde14bb2007-02-05 18:46:40 -0800755 dma_mark_clean(dma_addr, size);
John W. Linville878a97c2005-09-29 14:44:23 -0700756}
757
758void
759swiotlb_sync_single_range_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900760 unsigned long offset, size_t size,
761 enum dma_data_direction dir)
John W. Linville878a97c2005-09-29 14:44:23 -0700762{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700763 swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
764 SYNC_FOR_CPU);
John W. Linville878a97c2005-09-29 14:44:23 -0700765}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900766EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_cpu);
John W. Linville878a97c2005-09-29 14:44:23 -0700767
768void
769swiotlb_sync_single_range_for_device(struct device *hwdev, dma_addr_t dev_addr,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900770 unsigned long offset, size_t size,
771 enum dma_data_direction dir)
John W. Linville878a97c2005-09-29 14:44:23 -0700772{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700773 swiotlb_sync_single_range(hwdev, dev_addr, offset, size, dir,
774 SYNC_FOR_DEVICE);
John W. Linville878a97c2005-09-29 14:44:23 -0700775}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900776EXPORT_SYMBOL_GPL(swiotlb_sync_single_range_for_device);
John W. Linville878a97c2005-09-29 14:44:23 -0700777
778/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 * Map a set of buffers described by scatterlist in streaming mode for DMA.
780 * This is the scatter-gather version of the above swiotlb_map_single
781 * interface. Here the scatter gather list elements are each tagged with the
782 * appropriate dma address and length. They are obtained via
783 * sg_dma_{address,length}(SG).
784 *
785 * NOTE: An implementation may be able to use a smaller number of
786 * DMA address/length pairs than there are SG table elements.
787 * (for example via virtual mapping capabilities)
788 * The routine returns the number of addr/length pairs actually
789 * used, at most nents.
790 *
791 * Device ownership issues as mentioned above for swiotlb_map_single are the
792 * same here.
793 */
794int
Arthur Kepner309df0c2008-04-29 01:00:32 -0700795swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900796 enum dma_data_direction dir, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200798 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 int i;
800
Eric Sesterhenn34814542006-03-24 18:47:11 +0100801 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802
Jens Axboedbfd49f2007-05-11 14:56:18 +0200803 for_each_sg(sgl, sg, nelems, i) {
Ian Campbell961d7d02009-01-09 18:32:10 +0000804 phys_addr_t paddr = sg_phys(sg);
805 dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
Becky Brucebc40ac62008-12-22 10:26:08 -0800806
Ian Campbell961d7d02009-01-09 18:32:10 +0000807 if (range_needs_mapping(paddr, sg->length) ||
FUJITA Tomonori27979822008-09-10 01:06:49 +0900808 address_needs_mapping(hwdev, dev_addr, sg->length)) {
Becky Brucebc40ac62008-12-22 10:26:08 -0800809 void *map = map_single(hwdev, sg_phys(sg),
810 sg->length, dir);
Andi Kleen7e870232005-12-20 14:45:19 +0100811 if (!map) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 /* Don't panic here, we expect map_sg users
813 to do proper error handling. */
814 swiotlb_full(hwdev, sg->length, dir, 0);
Arthur Kepner309df0c2008-04-29 01:00:32 -0700815 swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
816 attrs);
Jens Axboedbfd49f2007-05-11 14:56:18 +0200817 sgl[0].dma_length = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 return 0;
819 }
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800820 sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821 } else
822 sg->dma_address = dev_addr;
823 sg->dma_length = sg->length;
824 }
825 return nelems;
826}
Arthur Kepner309df0c2008-04-29 01:00:32 -0700827EXPORT_SYMBOL(swiotlb_map_sg_attrs);
828
829int
830swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
831 int dir)
832{
833 return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
834}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900835EXPORT_SYMBOL(swiotlb_map_sg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
837/*
838 * Unmap a set of streaming mode DMA translations. Again, cpu read rules
839 * concerning calls here are the same as for swiotlb_unmap_single() above.
840 */
841void
Arthur Kepner309df0c2008-04-29 01:00:32 -0700842swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900843 int nelems, enum dma_data_direction dir, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200845 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 int i;
847
Eric Sesterhenn34814542006-03-24 18:47:11 +0100848 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849
Jens Axboedbfd49f2007-05-11 14:56:18 +0200850 for_each_sg(sgl, sg, nelems, i) {
Ian Campbell961d7d02009-01-09 18:32:10 +0000851 if (sg->dma_address != swiotlb_phys_to_bus(hwdev, sg_phys(sg)))
Ian Campbelle08e1f72008-12-16 12:17:30 -0800852 unmap_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
Jan Beulich93fbff62007-02-05 18:49:45 -0800853 sg->dma_length, dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 else if (dir == DMA_FROM_DEVICE)
Ian Campbell961d7d02009-01-09 18:32:10 +0000855 dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
Jens Axboedbfd49f2007-05-11 14:56:18 +0200856 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857}
Arthur Kepner309df0c2008-04-29 01:00:32 -0700858EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
859
860void
861swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
862 int dir)
863{
864 return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
865}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900866EXPORT_SYMBOL(swiotlb_unmap_sg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867
868/*
869 * Make physical memory consistent for a set of streaming mode DMA translations
870 * after a transfer.
871 *
872 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
873 * and usage.
874 */
Andrew Mortonbe6b0262007-02-12 00:52:17 -0800875static void
Jens Axboedbfd49f2007-05-11 14:56:18 +0200876swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
John W. Linvillede69e0f2005-09-29 14:44:57 -0700877 int nelems, int dir, int target)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878{
Jens Axboedbfd49f2007-05-11 14:56:18 +0200879 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 int i;
881
Eric Sesterhenn34814542006-03-24 18:47:11 +0100882 BUG_ON(dir == DMA_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Jens Axboedbfd49f2007-05-11 14:56:18 +0200884 for_each_sg(sgl, sg, nelems, i) {
Ian Campbell961d7d02009-01-09 18:32:10 +0000885 if (sg->dma_address != swiotlb_phys_to_bus(hwdev, sg_phys(sg)))
Ian Campbelle08e1f72008-12-16 12:17:30 -0800886 sync_single(hwdev, swiotlb_bus_to_virt(sg->dma_address),
John W. Linvillede69e0f2005-09-29 14:44:57 -0700887 sg->dma_length, dir, target);
Jan Beulichcde14bb2007-02-05 18:46:40 -0800888 else if (dir == DMA_FROM_DEVICE)
Ian Campbell961d7d02009-01-09 18:32:10 +0000889 dma_mark_clean(swiotlb_bus_to_virt(sg->dma_address), sg->dma_length);
Jens Axboedbfd49f2007-05-11 14:56:18 +0200890 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891}
892
893void
John W. Linville8270f3f2005-09-29 14:43:32 -0700894swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900895 int nelems, enum dma_data_direction dir)
John W. Linville8270f3f2005-09-29 14:43:32 -0700896{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700897 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
John W. Linville8270f3f2005-09-29 14:43:32 -0700898}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900899EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
John W. Linville8270f3f2005-09-29 14:43:32 -0700900
901void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
FUJITA Tomonori160c1d82009-01-05 23:59:02 +0900903 int nelems, enum dma_data_direction dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904{
John W. Linvillede69e0f2005-09-29 14:44:57 -0700905 swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900907EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
909int
FUJITA Tomonori8d8bb392008-07-25 19:44:49 -0700910swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800912 return (dma_addr == swiotlb_virt_to_bus(hwdev, io_tlb_overflow_buffer));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913}
FUJITA Tomonori874d6a92008-12-28 15:02:07 +0900914EXPORT_SYMBOL(swiotlb_dma_mapping_error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915
916/*
Tony Luck17e5ad62005-09-29 15:52:13 -0700917 * Return whether the given device DMA address mask can be supported
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 * properly. For example, if your device can only drive the low 24-bits
Tony Luck17e5ad62005-09-29 15:52:13 -0700919 * during bus mastering, then you would pass 0x00ffffff as the mask to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 * this function.
921 */
922int
Jan Beulich563aaf02007-02-05 18:51:25 -0800923swiotlb_dma_supported(struct device *hwdev, u64 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924{
Jeremy Fitzhardinge70a7d3c2008-12-22 10:26:05 -0800925 return swiotlb_virt_to_bus(hwdev, io_tlb_end - 1) <= mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927EXPORT_SYMBOL(swiotlb_dma_supported);