Branch data Line data Source code
1 : : /*
2 : : * Dynamic DMA mapping support.
3 : : *
4 : : * This implementation is a fallback for platforms that do not support
5 : : * I/O TLBs (aka DMA address translation hardware).
6 : : * Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
7 : : * Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
8 : : * Copyright (C) 2000, 2003 Hewlett-Packard Co
9 : : * David Mosberger-Tang <davidm@hpl.hp.com>
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.
14 : : * 04/07/.. ak Better overflow handling. Assorted fixes.
15 : : * 05/09/10 linville Add support for syncing ranges, support syncing for
16 : : * DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
17 : : * 08/12/11 beckyb Add highmem support
18 : : */
19 : :
20 : : #include <linux/cache.h>
21 : : #include <linux/dma-mapping.h>
22 : : #include <linux/mm.h>
23 : : #include <linux/export.h>
24 : : #include <linux/spinlock.h>
25 : : #include <linux/string.h>
26 : : #include <linux/swiotlb.h>
27 : : #include <linux/pfn.h>
28 : : #include <linux/types.h>
29 : : #include <linux/ctype.h>
30 : : #include <linux/highmem.h>
31 : : #include <linux/gfp.h>
32 : :
33 : : #include <asm/io.h>
34 : : #include <asm/dma.h>
35 : : #include <asm/scatterlist.h>
36 : :
37 : : #include <linux/init.h>
38 : : #include <linux/bootmem.h>
39 : : #include <linux/iommu-helper.h>
40 : :
41 : : #define CREATE_TRACE_POINTS
42 : : #include <trace/events/swiotlb.h>
43 : :
44 : : #define OFFSET(val,align) ((unsigned long) \
45 : : ( (val) & ( (align) - 1)))
46 : :
47 : : #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
48 : :
49 : : /*
50 : : * Minimum IO TLB size to bother booting with. Systems with mainly
51 : : * 64bit capable cards will only lightly use the swiotlb. If we can't
52 : : * allocate a contiguous 1MB, we're probably in trouble anyway.
53 : : */
54 : : #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
55 : :
56 : : int swiotlb_force;
57 : :
58 : : /*
59 : : * Used to do a quick range check in swiotlb_tbl_unmap_single and
60 : : * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
61 : : * API.
62 : : */
63 : : static phys_addr_t io_tlb_start, io_tlb_end;
64 : :
65 : : /*
66 : : * The number of IO TLB blocks (in groups of 64) between io_tlb_start and
67 : : * io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
68 : : */
69 : : static unsigned long io_tlb_nslabs;
70 : :
71 : : /*
72 : : * When the IOMMU overflows we return a fallback buffer. This sets the size.
73 : : */
74 : : static unsigned long io_tlb_overflow = 32*1024;
75 : :
76 : : static phys_addr_t io_tlb_overflow_buffer;
77 : :
78 : : /*
79 : : * This is a free list describing the number of free entries available from
80 : : * each index
81 : : */
82 : : static unsigned int *io_tlb_list;
83 : : static unsigned int io_tlb_index;
84 : :
85 : : /*
86 : : * We need to save away the original address corresponding to a mapped entry
87 : : * for the sync operations.
88 : : */
89 : : static phys_addr_t *io_tlb_orig_addr;
90 : :
91 : : /*
92 : : * Protect the above data structures in the map and unmap calls
93 : : */
94 : : static DEFINE_SPINLOCK(io_tlb_lock);
95 : :
96 : : static int late_alloc;
97 : :
98 : : static int __init
99 : 0 : setup_io_tlb_npages(char *str)
100 : : {
101 [ # # ]: 0 : if (isdigit(*str)) {
102 : 0 : io_tlb_nslabs = simple_strtoul(str, &str, 0);
103 : : /* avoid tail segment of size < IO_TLB_SEGSIZE */
104 : 0 : io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
105 : : }
106 [ # # ]: 0 : if (*str == ',')
107 : 0 : ++str;
108 [ # # ]: 0 : if (!strcmp(str, "force"))
109 : 0 : swiotlb_force = 1;
110 : :
111 : 0 : return 0;
112 : : }
113 : : early_param("swiotlb", setup_io_tlb_npages);
114 : : /* make io_tlb_overflow tunable too? */
115 : :
116 : 0 : unsigned long swiotlb_nr_tbl(void)
117 : : {
118 : 0 : return io_tlb_nslabs;
119 : : }
120 : : EXPORT_SYMBOL_GPL(swiotlb_nr_tbl);
121 : :
122 : : /* default to 64MB */
123 : : #define IO_TLB_DEFAULT_SIZE (64UL<<20)
124 : 0 : unsigned long swiotlb_size_or_default(void)
125 : : {
126 : : unsigned long size;
127 : :
128 : 0 : size = io_tlb_nslabs << IO_TLB_SHIFT;
129 : :
130 [ # # ]: 0 : return size ? size : (IO_TLB_DEFAULT_SIZE);
131 : : }
132 : :
133 : : /* Note that this doesn't work with highmem page */
134 : : static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
135 : : volatile void *address)
136 : : {
137 : : return phys_to_dma(hwdev, virt_to_phys(address));
138 : : }
139 : :
140 : : static bool no_iotlb_memory;
141 : :
142 : 0 : void swiotlb_print_info(void)
143 : : {
144 : 0 : unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
145 : : unsigned char *vstart, *vend;
146 : :
147 [ # # ]: 0 : if (no_iotlb_memory) {
148 : 0 : pr_warn("software IO TLB: No low mem\n");
149 : 0 : return;
150 : : }
151 : :
152 : 0 : vstart = phys_to_virt(io_tlb_start);
153 : 0 : vend = phys_to_virt(io_tlb_end);
154 : :
155 : 0 : printk(KERN_INFO "software IO TLB [mem %#010llx-%#010llx] (%luMB) mapped at [%p-%p]\n",
156 : : (unsigned long long)io_tlb_start,
157 : : (unsigned long long)io_tlb_end,
158 : : bytes >> 20, vstart, vend - 1);
159 : : }
160 : :
161 : 0 : int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
162 : : {
163 : : void *v_overflow_buffer;
164 : : unsigned long i, bytes;
165 : :
166 : 0 : bytes = nslabs << IO_TLB_SHIFT;
167 : :
168 : 0 : io_tlb_nslabs = nslabs;
169 : 0 : io_tlb_start = __pa(tlb);
170 : 0 : io_tlb_end = io_tlb_start + bytes;
171 : :
172 : : /*
173 : : * Get the overflow emergency buffer
174 : : */
175 : 0 : v_overflow_buffer = alloc_bootmem_low_pages_nopanic(
176 : : PAGE_ALIGN(io_tlb_overflow));
177 [ # # ]: 0 : if (!v_overflow_buffer)
178 : : return -ENOMEM;
179 : :
180 : 0 : io_tlb_overflow_buffer = __pa(v_overflow_buffer);
181 : :
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 : 0 : io_tlb_list = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
188 [ # # ]: 0 : for (i = 0; i < io_tlb_nslabs; i++)
189 : 0 : io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
190 : 0 : io_tlb_index = 0;
191 : 0 : io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));
192 : :
193 [ # # ]: 0 : if (verbose)
194 : 0 : swiotlb_print_info();
195 : :
196 : : return 0;
197 : : }
198 : :
199 : : /*
200 : : * Statically reserve bounce buffer space and initialize bounce buffer data
201 : : * structures for the software IO TLB used to implement the DMA API.
202 : : */
203 : : void __init
204 : 0 : swiotlb_init(int verbose)
205 : : {
206 : : size_t default_size = IO_TLB_DEFAULT_SIZE;
207 : : unsigned char *vstart;
208 : : unsigned long bytes;
209 : :
210 [ # # ]: 0 : if (!io_tlb_nslabs) {
211 : 0 : io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
212 : : io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
213 : : }
214 : :
215 : 0 : bytes = io_tlb_nslabs << IO_TLB_SHIFT;
216 : :
217 : : /* Get IO TLB memory from the low pages */
218 : 0 : vstart = alloc_bootmem_low_pages_nopanic(PAGE_ALIGN(bytes));
219 [ # # ][ # # ]: 0 : if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
220 : 0 : return;
221 : :
222 [ # # ]: 0 : if (io_tlb_start)
223 : 0 : free_bootmem(io_tlb_start,
224 : 0 : PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
225 : 0 : pr_warn("Cannot allocate SWIOTLB buffer");
226 : 0 : no_iotlb_memory = true;
227 : : }
228 : :
229 : : /*
230 : : * Systems with larger DMA zones (those that don't support ISA) can
231 : : * initialize the swiotlb later using the slab allocator if needed.
232 : : * This should be just like above, but with some error catching.
233 : : */
234 : : int
235 : 0 : swiotlb_late_init_with_default_size(size_t default_size)
236 : : {
237 : 0 : unsigned long bytes, req_nslabs = io_tlb_nslabs;
238 : : unsigned char *vstart = NULL;
239 : : unsigned int order;
240 : : int rc = 0;
241 : :
242 [ # # ]: 0 : if (!io_tlb_nslabs) {
243 : 0 : io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
244 : 0 : io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
245 : : }
246 : :
247 : : /*
248 : : * Get IO TLB memory from the low pages
249 : : */
250 [ # # ][ # # ]: 0 : order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
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251 : 0 : io_tlb_nslabs = SLABS_PER_PAGE << order;
252 : 0 : bytes = io_tlb_nslabs << IO_TLB_SHIFT;
253 : :
254 [ # # ]: 0 : while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
255 : 0 : vstart = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
256 : : order);
257 [ # # ]: 0 : if (vstart)
258 : : break;
259 : 0 : order--;
260 : : }
261 : :
262 [ # # ]: 0 : if (!vstart) {
263 : 0 : io_tlb_nslabs = req_nslabs;
264 : 0 : return -ENOMEM;
265 : : }
266 [ # # ][ # # ]: 0 : if (order != get_order(bytes)) {
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267 : 0 : printk(KERN_WARNING "Warning: only able to allocate %ld MB "
268 : 0 : "for software IO TLB\n", (PAGE_SIZE << order) >> 20);
269 : 0 : io_tlb_nslabs = SLABS_PER_PAGE << order;
270 : : }
271 : 0 : rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs);
272 [ # # ]: 0 : if (rc)
273 : 0 : free_pages((unsigned long)vstart, order);
274 : 0 : return rc;
275 : : }
276 : :
277 : : int
278 : 0 : swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
279 : : {
280 : : unsigned long i, bytes;
281 : : unsigned char *v_overflow_buffer;
282 : :
283 : 0 : bytes = nslabs << IO_TLB_SHIFT;
284 : :
285 : 0 : io_tlb_nslabs = nslabs;
286 : 0 : io_tlb_start = virt_to_phys(tlb);
287 : 0 : io_tlb_end = io_tlb_start + bytes;
288 : :
289 [ # # ]: 0 : memset(tlb, 0, bytes);
290 : :
291 : : /*
292 : : * Get the overflow emergency buffer
293 : : */
294 [ # # ][ # # ]: 0 : v_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
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295 : 0 : get_order(io_tlb_overflow));
296 [ # # ]: 0 : if (!v_overflow_buffer)
297 : : goto cleanup2;
298 : :
299 : 0 : io_tlb_overflow_buffer = virt_to_phys(v_overflow_buffer);
300 : :
301 : : /*
302 : : * Allocate and initialize the free list array. This array is used
303 : : * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
304 : : * between io_tlb_start and io_tlb_end.
305 : : */
306 [ # # ][ # # ]: 0 : io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
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307 : 0 : get_order(io_tlb_nslabs * sizeof(int)));
308 [ # # ]: 0 : if (!io_tlb_list)
309 : : goto cleanup3;
310 : :
311 [ # # ]: 0 : for (i = 0; i < io_tlb_nslabs; i++)
312 : 0 : io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
313 : 0 : io_tlb_index = 0;
314 : :
315 : 0 : io_tlb_orig_addr = (phys_addr_t *)
316 [ # # ][ # # ]: 0 : __get_free_pages(GFP_KERNEL,
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317 : 0 : get_order(io_tlb_nslabs *
318 : : sizeof(phys_addr_t)));
319 [ # # ]: 0 : if (!io_tlb_orig_addr)
320 : : goto cleanup4;
321 : :
322 [ # # ]: 0 : memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
323 : :
324 : 0 : swiotlb_print_info();
325 : :
326 : 0 : late_alloc = 1;
327 : :
328 : 0 : return 0;
329 : :
330 : : cleanup4:
331 [ # # ][ # # ]: 0 : free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
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332 : : sizeof(int)));
333 : 0 : io_tlb_list = NULL;
334 : : cleanup3:
335 [ # # ][ # # ]: 0 : free_pages((unsigned long)v_overflow_buffer,
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336 : 0 : get_order(io_tlb_overflow));
337 : 0 : io_tlb_overflow_buffer = 0;
338 : : cleanup2:
339 : 0 : io_tlb_end = 0;
340 : 0 : io_tlb_start = 0;
341 : 0 : io_tlb_nslabs = 0;
342 : 0 : return -ENOMEM;
343 : : }
344 : :
345 : 0 : void __init swiotlb_free(void)
346 : : {
347 [ # # ]: 0 : if (!io_tlb_orig_addr)
348 : 0 : return;
349 : :
350 [ # # ]: 0 : if (late_alloc) {
351 [ # # ][ # # ]: 0 : free_pages((unsigned long)phys_to_virt(io_tlb_overflow_buffer),
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352 : 0 : get_order(io_tlb_overflow));
353 [ # # ][ # # ]: 0 : free_pages((unsigned long)io_tlb_orig_addr,
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354 : 0 : get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
355 [ # # ][ # # ]: 0 : free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
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356 : : sizeof(int)));
357 [ # # ][ # # ]: 0 : free_pages((unsigned long)phys_to_virt(io_tlb_start),
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358 : 0 : get_order(io_tlb_nslabs << IO_TLB_SHIFT));
359 : : } else {
360 : 0 : free_bootmem_late(io_tlb_overflow_buffer,
361 : 0 : PAGE_ALIGN(io_tlb_overflow));
362 : 0 : free_bootmem_late(__pa(io_tlb_orig_addr),
363 : 0 : PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));
364 : 0 : free_bootmem_late(__pa(io_tlb_list),
365 : 0 : PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
366 : 0 : free_bootmem_late(io_tlb_start,
367 : 0 : PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
368 : : }
369 : 0 : io_tlb_nslabs = 0;
370 : : }
371 : :
372 : : static int is_swiotlb_buffer(phys_addr_t paddr)
373 : : {
374 [ # # ][ # # ]: 0 : return paddr >= io_tlb_start && paddr < io_tlb_end;
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375 : : }
376 : :
377 : : /*
378 : : * Bounce: copy the swiotlb buffer back to the original dma location
379 : : */
380 : 0 : static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr,
381 : : size_t size, enum dma_data_direction dir)
382 : : {
383 : 0 : unsigned long pfn = PFN_DOWN(orig_addr);
384 : : unsigned char *vaddr = phys_to_virt(tlb_addr);
385 : :
386 [ # # ]: 0 : if (PageHighMem(pfn_to_page(pfn))) {
387 : : /* The buffer does not have a mapping. Map it in and copy */
388 : 0 : unsigned int offset = orig_addr & ~PAGE_MASK;
389 : : char *buffer;
390 : : unsigned int sz = 0;
391 : : unsigned long flags;
392 : :
393 [ # # ]: 0 : while (size) {
394 : 0 : sz = min_t(size_t, PAGE_SIZE - offset, size);
395 : :
396 : : local_irq_save(flags);
397 : 0 : buffer = kmap_atomic(pfn_to_page(pfn));
398 [ # # ]: 0 : if (dir == DMA_TO_DEVICE)
399 : 0 : memcpy(vaddr, buffer + offset, sz);
400 : : else
401 : 0 : memcpy(buffer + offset, vaddr, sz);
402 : 0 : kunmap_atomic(buffer);
403 [ # # ]: 0 : local_irq_restore(flags);
404 : :
405 : 0 : size -= sz;
406 : 0 : pfn++;
407 : 0 : vaddr += sz;
408 : : offset = 0;
409 : : }
410 [ # # ]: 0 : } else if (dir == DMA_TO_DEVICE) {
411 : 0 : memcpy(vaddr, phys_to_virt(orig_addr), size);
412 : : } else {
413 : 0 : memcpy(phys_to_virt(orig_addr), vaddr, size);
414 : : }
415 : 0 : }
416 : :
417 : 0 : phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
418 : : dma_addr_t tbl_dma_addr,
419 : : phys_addr_t orig_addr, size_t size,
420 : : enum dma_data_direction dir)
421 : : {
422 : : unsigned long flags;
423 : : phys_addr_t tlb_addr;
424 : : unsigned int nslots, stride, index, wrap;
425 : : int i;
426 : : unsigned long mask;
427 : : unsigned long offset_slots;
428 : : unsigned long max_slots;
429 : :
430 [ # # ]: 0 : if (no_iotlb_memory)
431 : 0 : panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
432 : :
433 : : mask = dma_get_seg_boundary(hwdev);
434 : :
435 : 0 : tbl_dma_addr &= mask;
436 : :
437 : 0 : offset_slots = ALIGN(tbl_dma_addr, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
438 : :
439 : : /*
440 : : * Carefully handle integer overflow which can occur when mask == ~0UL.
441 : : */
442 : : max_slots = mask + 1
443 : 0 : ? ALIGN(mask + 1, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT
444 [ # # ]: 0 : : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
445 : :
446 : : /*
447 : : * For mappings greater than a page, we limit the stride (and
448 : : * hence alignment) to a page size.
449 : : */
450 : 0 : nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
451 [ # # ]: 0 : if (size > PAGE_SIZE)
452 : : stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
453 : : else
454 : : stride = 1;
455 : :
456 [ # # ]: 0 : BUG_ON(!nslots);
457 : :
458 : : /*
459 : : * Find suitable number of IO TLB entries size that will fit this
460 : : * request and allocate a buffer from that IO TLB pool.
461 : : */
462 : 0 : spin_lock_irqsave(&io_tlb_lock, flags);
463 : 0 : index = ALIGN(io_tlb_index, stride);
464 [ # # ]: 0 : if (index >= io_tlb_nslabs)
465 : : index = 0;
466 : : wrap = index;
467 : :
468 : : do {
469 [ # # ]: 0 : while (iommu_is_span_boundary(index, nslots, offset_slots,
470 : : max_slots)) {
471 : 0 : index += stride;
472 [ # # ]: 0 : if (index >= io_tlb_nslabs)
473 : : index = 0;
474 [ # # ]: 0 : if (index == wrap)
475 : : goto not_found;
476 : : }
477 : :
478 : : /*
479 : : * If we find a slot that indicates we have 'nslots' number of
480 : : * contiguous buffers, we allocate the buffers from that slot
481 : : * and mark the entries as '0' indicating unavailable.
482 : : */
483 [ # # ]: 0 : if (io_tlb_list[index] >= nslots) {
484 : : int count = 0;
485 : :
486 [ # # ]: 0 : for (i = index; i < (int) (index + nslots); i++)
487 : 0 : io_tlb_list[i] = 0;
488 [ # # ][ # # ]: 0 : for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
489 : 0 : io_tlb_list[i] = ++count;
490 : 0 : tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT);
491 : :
492 : : /*
493 : : * Update the indices to avoid searching in the next
494 : : * round.
495 : : */
496 : 0 : io_tlb_index = ((index + nslots) < io_tlb_nslabs
497 [ # # ]: 0 : ? (index + nslots) : 0);
498 : :
499 : : goto found;
500 : : }
501 : 0 : index += stride;
502 [ # # ]: 0 : if (index >= io_tlb_nslabs)
503 : : index = 0;
504 [ # # ]: 0 : } while (index != wrap);
505 : :
506 : : not_found:
507 : : spin_unlock_irqrestore(&io_tlb_lock, flags);
508 : 0 : dev_warn(hwdev, "swiotlb buffer is full\n");
509 : 0 : return SWIOTLB_MAP_ERROR;
510 : : found:
511 : : spin_unlock_irqrestore(&io_tlb_lock, flags);
512 : :
513 : : /*
514 : : * Save away the mapping from the original address to the DMA address.
515 : : * This is needed when we sync the memory. Then we sync the buffer if
516 : : * needed.
517 : : */
518 [ # # ]: 0 : for (i = 0; i < nslots; i++)
519 : 0 : io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT);
520 [ # # ]: 0 : if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
521 : 0 : swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE);
522 : :
523 : 0 : return tlb_addr;
524 : : }
525 : : EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single);
526 : :
527 : : /*
528 : : * Allocates bounce buffer and returns its kernel virtual address.
529 : : */
530 : :
531 : 0 : phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size,
532 : : enum dma_data_direction dir)
533 : : {
534 : 0 : dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start);
535 : :
536 : 0 : return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir);
537 : : }
538 : :
539 : : /*
540 : : * dma_addr is the kernel virtual address of the bounce buffer to unmap.
541 : : */
542 : 0 : void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
543 : : size_t size, enum dma_data_direction dir)
544 : : {
545 : : unsigned long flags;
546 : 0 : int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
547 : 0 : int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
548 : 0 : phys_addr_t orig_addr = io_tlb_orig_addr[index];
549 : :
550 : : /*
551 : : * First, sync the memory before unmapping the entry
552 : : */
553 [ # # ][ # # ]: 0 : if (orig_addr && ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
554 : 0 : swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE);
555 : :
556 : : /*
557 : : * Return the buffer to the free list by setting the corresponding
558 : : * entries to indicate the number of contiguous entries available.
559 : : * While returning the entries to the free list, we merge the entries
560 : : * with slots below and above the pool being returned.
561 : : */
562 : 0 : spin_lock_irqsave(&io_tlb_lock, flags);
563 : : {
564 [ # # ]: 0 : count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
565 : 0 : io_tlb_list[index + nslots] : 0);
566 : : /*
567 : : * Step 1: return the slots to the free list, merging the
568 : : * slots with superceeding slots
569 : : */
570 [ # # ]: 0 : for (i = index + nslots - 1; i >= index; i--)
571 : 0 : io_tlb_list[i] = ++count;
572 : : /*
573 : : * Step 2: merge the returned slots with the preceding slots,
574 : : * if available (non zero)
575 : : */
576 [ # # ][ # # ]: 0 : for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
577 : 0 : io_tlb_list[i] = ++count;
578 : : }
579 : : spin_unlock_irqrestore(&io_tlb_lock, flags);
580 : 0 : }
581 : : EXPORT_SYMBOL_GPL(swiotlb_tbl_unmap_single);
582 : :
583 : 0 : void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
584 : : size_t size, enum dma_data_direction dir,
585 : : enum dma_sync_target target)
586 : : {
587 : 0 : int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
588 : 0 : phys_addr_t orig_addr = io_tlb_orig_addr[index];
589 : :
590 : 0 : orig_addr += (unsigned long)tlb_addr & ((1 << IO_TLB_SHIFT) - 1);
591 : :
592 [ # # # ]: 0 : switch (target) {
593 : : case SYNC_FOR_CPU:
594 [ # # ]: 0 : if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
595 : 0 : swiotlb_bounce(orig_addr, tlb_addr,
596 : : size, DMA_FROM_DEVICE);
597 : : else
598 [ # # ]: 0 : BUG_ON(dir != DMA_TO_DEVICE);
599 : : break;
600 : : case SYNC_FOR_DEVICE:
601 [ # # ]: 0 : if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
602 : 0 : swiotlb_bounce(orig_addr, tlb_addr,
603 : : size, DMA_TO_DEVICE);
604 : : else
605 [ # # ]: 0 : BUG_ON(dir != DMA_FROM_DEVICE);
606 : : break;
607 : : default:
608 : 0 : BUG();
609 : : }
610 : 0 : }
611 : : EXPORT_SYMBOL_GPL(swiotlb_tbl_sync_single);
612 : :
613 : : void *
614 : 0 : swiotlb_alloc_coherent(struct device *hwdev, size_t size,
615 : : dma_addr_t *dma_handle, gfp_t flags)
616 : : {
617 : : dma_addr_t dev_addr;
618 : : void *ret;
619 [ # # ][ # # ]: 0 : int order = get_order(size);
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620 : : u64 dma_mask = DMA_BIT_MASK(32);
621 : :
622 [ # # ][ # # ]: 0 : if (hwdev && hwdev->coherent_dma_mask)
623 : : dma_mask = hwdev->coherent_dma_mask;
624 : :
625 : 0 : ret = (void *)__get_free_pages(flags, order);
626 [ # # ]: 0 : if (ret) {
627 : : dev_addr = swiotlb_virt_to_bus(hwdev, ret);
628 [ # # ]: 0 : if (dev_addr + size - 1 > dma_mask) {
629 : : /*
630 : : * The allocated memory isn't reachable by the device.
631 : : */
632 : 0 : free_pages((unsigned long) ret, order);
633 : : ret = NULL;
634 : : }
635 : : }
636 [ # # ]: 0 : if (!ret) {
637 : : /*
638 : : * We are either out of memory or the device can't DMA to
639 : : * GFP_DMA memory; fall back on map_single(), which
640 : : * will grab memory from the lowest available address range.
641 : : */
642 : 0 : phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
643 [ # # ]: 0 : if (paddr == SWIOTLB_MAP_ERROR)
644 : : return NULL;
645 : :
646 : : ret = phys_to_virt(paddr);
647 : : dev_addr = phys_to_dma(hwdev, paddr);
648 : :
649 : : /* Confirm address can be DMA'd by device */
650 [ # # ]: 0 : if (dev_addr + size - 1 > dma_mask) {
651 : 0 : printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
652 : : (unsigned long long)dma_mask,
653 : : (unsigned long long)dev_addr);
654 : :
655 : : /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
656 : 0 : swiotlb_tbl_unmap_single(hwdev, paddr,
657 : : size, DMA_TO_DEVICE);
658 : 0 : return NULL;
659 : : }
660 : : }
661 : :
662 : 0 : *dma_handle = dev_addr;
663 [ # # ]: 0 : memset(ret, 0, size);
664 : :
665 : 0 : return ret;
666 : : }
667 : : EXPORT_SYMBOL(swiotlb_alloc_coherent);
668 : :
669 : : void
670 : 0 : swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
671 : : dma_addr_t dev_addr)
672 : : {
673 : : phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
674 : :
675 [ # # ]: 0 : WARN_ON(irqs_disabled());
676 [ # # ]: 0 : if (!is_swiotlb_buffer(paddr))
677 [ # # ][ # # ]: 0 : free_pages((unsigned long)vaddr, get_order(size));
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678 : : else
679 : : /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */
680 : 0 : swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE);
681 : 0 : }
682 : : EXPORT_SYMBOL(swiotlb_free_coherent);
683 : :
684 : : static void
685 : 0 : swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir,
686 : : int do_panic)
687 : : {
688 : : /*
689 : : * Ran out of IOMMU space for this operation. This is very bad.
690 : : * Unfortunately the drivers cannot handle this operation properly.
691 : : * unless they check for dma_mapping_error (most don't)
692 : : * When the mapping is small enough return a static buffer to limit
693 : : * the damage, or panic when the transfer is too big.
694 : : */
695 [ # # ]: 0 : printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
696 : : "device %s\n", size, dev ? dev_name(dev) : "?");
697 : :
698 [ # # ][ # # ]: 0 : if (size <= io_tlb_overflow || !do_panic)
699 : 0 : return;
700 : :
701 [ # # ]: 0 : if (dir == DMA_BIDIRECTIONAL)
702 : 0 : panic("DMA: Random memory could be DMA accessed\n");
703 [ # # ]: 0 : if (dir == DMA_FROM_DEVICE)
704 : 0 : panic("DMA: Random memory could be DMA written\n");
705 [ # # ]: 0 : if (dir == DMA_TO_DEVICE)
706 : 0 : panic("DMA: Random memory could be DMA read\n");
707 : : }
708 : :
709 : : /*
710 : : * Map a single buffer of the indicated size for DMA in streaming mode. The
711 : : * physical address to use is returned.
712 : : *
713 : : * Once the device is given the dma address, the device owns this memory until
714 : : * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed.
715 : : */
716 : 0 : dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
717 : : unsigned long offset, size_t size,
718 : : enum dma_data_direction dir,
719 : : struct dma_attrs *attrs)
720 : : {
721 : 0 : phys_addr_t map, phys = page_to_phys(page) + offset;
722 : : dma_addr_t dev_addr = phys_to_dma(dev, phys);
723 : :
724 [ # # ]: 0 : BUG_ON(dir == DMA_NONE);
725 : : /*
726 : : * If the address happens to be in the device's DMA window,
727 : : * we can safely return the device addr and not worry about bounce
728 : : * buffering it.
729 : : */
730 [ # # ][ # # ]: 0 : if (dma_capable(dev, dev_addr, size) && !swiotlb_force)
731 : : return dev_addr;
732 : :
733 : 0 : trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
734 : :
735 : : /* Oh well, have to allocate and map a bounce buffer. */
736 : 0 : map = map_single(dev, phys, size, dir);
737 [ # # ]: 0 : if (map == SWIOTLB_MAP_ERROR) {
738 : 0 : swiotlb_full(dev, size, dir, 1);
739 : 0 : return phys_to_dma(dev, io_tlb_overflow_buffer);
740 : : }
741 : :
742 : : dev_addr = phys_to_dma(dev, map);
743 : :
744 : : /* Ensure that the address returned is DMA'ble */
745 [ # # ]: 0 : if (!dma_capable(dev, dev_addr, size)) {
746 : 0 : swiotlb_tbl_unmap_single(dev, map, size, dir);
747 : 0 : return phys_to_dma(dev, io_tlb_overflow_buffer);
748 : : }
749 : :
750 : : return dev_addr;
751 : : }
752 : : EXPORT_SYMBOL_GPL(swiotlb_map_page);
753 : :
754 : : /*
755 : : * Unmap a single streaming mode DMA translation. The dma_addr and size must
756 : : * match what was provided for in a previous swiotlb_map_page call. All
757 : : * other usages are undefined.
758 : : *
759 : : * After this call, reads by the cpu to the buffer are guaranteed to see
760 : : * whatever the device wrote there.
761 : : */
762 : 0 : static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
763 : : size_t size, enum dma_data_direction dir)
764 : : {
765 : : phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
766 : :
767 [ # # ]: 0 : BUG_ON(dir == DMA_NONE);
768 : :
769 [ # # ]: 0 : if (is_swiotlb_buffer(paddr)) {
770 : 0 : swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
771 : 0 : return;
772 : : }
773 : :
774 [ # # ]: 0 : if (dir != DMA_FROM_DEVICE)
775 : : return;
776 : :
777 : : /*
778 : : * phys_to_virt doesn't work with hihgmem page but we could
779 : : * call dma_mark_clean() with hihgmem page here. However, we
780 : : * are fine since dma_mark_clean() is null on POWERPC. We can
781 : : * make dma_mark_clean() take a physical address if necessary.
782 : : */
783 : : dma_mark_clean(phys_to_virt(paddr), size);
784 : : }
785 : :
786 : 0 : void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
787 : : size_t size, enum dma_data_direction dir,
788 : : struct dma_attrs *attrs)
789 : : {
790 : 0 : unmap_single(hwdev, dev_addr, size, dir);
791 : 0 : }
792 : : EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
793 : :
794 : : /*
795 : : * Make physical memory consistent for a single streaming mode DMA translation
796 : : * after a transfer.
797 : : *
798 : : * If you perform a swiotlb_map_page() but wish to interrogate the buffer
799 : : * using the cpu, yet do not wish to teardown the dma mapping, you must
800 : : * call this function before doing so. At the next point you give the dma
801 : : * address back to the card, you must first perform a
802 : : * swiotlb_dma_sync_for_device, and then the device again owns the buffer
803 : : */
804 : : static void
805 : 0 : swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
806 : : size_t size, enum dma_data_direction dir,
807 : : enum dma_sync_target target)
808 : : {
809 : : phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
810 : :
811 [ # # ]: 0 : BUG_ON(dir == DMA_NONE);
812 : :
813 [ # # ]: 0 : if (is_swiotlb_buffer(paddr)) {
814 : 0 : swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
815 : 0 : return;
816 : : }
817 : :
818 [ # # ]: 0 : if (dir != DMA_FROM_DEVICE)
819 : : return;
820 : :
821 : : dma_mark_clean(phys_to_virt(paddr), size);
822 : : }
823 : :
824 : : void
825 : 0 : swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
826 : : size_t size, enum dma_data_direction dir)
827 : : {
828 : 0 : swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
829 : 0 : }
830 : : EXPORT_SYMBOL(swiotlb_sync_single_for_cpu);
831 : :
832 : : void
833 : 0 : swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
834 : : size_t size, enum dma_data_direction dir)
835 : : {
836 : 0 : swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
837 : 0 : }
838 : : EXPORT_SYMBOL(swiotlb_sync_single_for_device);
839 : :
840 : : /*
841 : : * Map a set of buffers described by scatterlist in streaming mode for DMA.
842 : : * This is the scatter-gather version of the above swiotlb_map_page
843 : : * interface. Here the scatter gather list elements are each tagged with the
844 : : * appropriate dma address and length. They are obtained via
845 : : * sg_dma_{address,length}(SG).
846 : : *
847 : : * NOTE: An implementation may be able to use a smaller number of
848 : : * DMA address/length pairs than there are SG table elements.
849 : : * (for example via virtual mapping capabilities)
850 : : * The routine returns the number of addr/length pairs actually
851 : : * used, at most nents.
852 : : *
853 : : * Device ownership issues as mentioned above for swiotlb_map_page are the
854 : : * same here.
855 : : */
856 : : int
857 : 0 : swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
858 : : enum dma_data_direction dir, struct dma_attrs *attrs)
859 : : {
860 : : struct scatterlist *sg;
861 : : int i;
862 : :
863 [ # # ]: 0 : BUG_ON(dir == DMA_NONE);
864 : :
865 [ # # ]: 0 : for_each_sg(sgl, sg, nelems, i) {
866 : : phys_addr_t paddr = sg_phys(sg);
867 : : dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
868 : :
869 [ # # ][ # # ]: 0 : if (swiotlb_force ||
870 : 0 : !dma_capable(hwdev, dev_addr, sg->length)) {
871 : 0 : phys_addr_t map = map_single(hwdev, sg_phys(sg),
872 : : sg->length, dir);
873 [ # # ]: 0 : if (map == SWIOTLB_MAP_ERROR) {
874 : : /* Don't panic here, we expect map_sg users
875 : : to do proper error handling. */
876 : 0 : swiotlb_full(hwdev, sg->length, dir, 0);
877 : 0 : swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
878 : : attrs);
879 : 0 : sg_dma_len(sgl) = 0;
880 : 0 : return 0;
881 : : }
882 : 0 : sg->dma_address = phys_to_dma(hwdev, map);
883 : : } else
884 : 0 : sg->dma_address = dev_addr;
885 : : sg_dma_len(sg) = sg->length;
886 : : }
887 : : return nelems;
888 : : }
889 : : EXPORT_SYMBOL(swiotlb_map_sg_attrs);
890 : :
891 : : int
892 : 0 : swiotlb_map_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
893 : : enum dma_data_direction dir)
894 : : {
895 : 0 : return swiotlb_map_sg_attrs(hwdev, sgl, nelems, dir, NULL);
896 : : }
897 : : EXPORT_SYMBOL(swiotlb_map_sg);
898 : :
899 : : /*
900 : : * Unmap a set of streaming mode DMA translations. Again, cpu read rules
901 : : * concerning calls here are the same as for swiotlb_unmap_page() above.
902 : : */
903 : : void
904 : 0 : swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
905 : : int nelems, enum dma_data_direction dir, struct dma_attrs *attrs)
906 : : {
907 : : struct scatterlist *sg;
908 : : int i;
909 : :
910 [ # # ]: 0 : BUG_ON(dir == DMA_NONE);
911 : :
912 [ # # ]: 0 : for_each_sg(sgl, sg, nelems, i)
913 : 0 : unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir);
914 : :
915 : 0 : }
916 : : EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
917 : :
918 : : void
919 : 0 : swiotlb_unmap_sg(struct device *hwdev, struct scatterlist *sgl, int nelems,
920 : : enum dma_data_direction dir)
921 : : {
922 : 0 : return swiotlb_unmap_sg_attrs(hwdev, sgl, nelems, dir, NULL);
923 : : }
924 : : EXPORT_SYMBOL(swiotlb_unmap_sg);
925 : :
926 : : /*
927 : : * Make physical memory consistent for a set of streaming mode DMA translations
928 : : * after a transfer.
929 : : *
930 : : * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
931 : : * and usage.
932 : : */
933 : : static void
934 : 0 : swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
935 : : int nelems, enum dma_data_direction dir,
936 : : enum dma_sync_target target)
937 : : {
938 : : struct scatterlist *sg;
939 : : int i;
940 : :
941 [ # # ]: 0 : for_each_sg(sgl, sg, nelems, i)
942 : 0 : swiotlb_sync_single(hwdev, sg->dma_address,
943 : : sg_dma_len(sg), dir, target);
944 : 0 : }
945 : :
946 : : void
947 : 0 : swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
948 : : int nelems, enum dma_data_direction dir)
949 : : {
950 : 0 : swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
951 : 0 : }
952 : : EXPORT_SYMBOL(swiotlb_sync_sg_for_cpu);
953 : :
954 : : void
955 : 0 : swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
956 : : int nelems, enum dma_data_direction dir)
957 : : {
958 : 0 : swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
959 : 0 : }
960 : : EXPORT_SYMBOL(swiotlb_sync_sg_for_device);
961 : :
962 : : int
963 : 0 : swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
964 : : {
965 : 0 : return (dma_addr == phys_to_dma(hwdev, io_tlb_overflow_buffer));
966 : : }
967 : : EXPORT_SYMBOL(swiotlb_dma_mapping_error);
968 : :
969 : : /*
970 : : * Return whether the given device DMA address mask can be supported
971 : : * properly. For example, if your device can only drive the low 24-bits
972 : : * during bus mastering, then you would pass 0x00ffffff as the mask to
973 : : * this function.
974 : : */
975 : : int
976 : 0 : swiotlb_dma_supported(struct device *hwdev, u64 mask)
977 : : {
978 : 0 : return phys_to_dma(hwdev, io_tlb_end - 1) <= mask;
979 : : }
980 : : EXPORT_SYMBOL(swiotlb_dma_supported);
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