Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 | // SPDX-License-Identifier: GPL-2.0-only
/*
* Dynamic DMA mapping support.
*
* This implementation is a fallback for platforms that do not support
* I/O TLBs (aka DMA address translation hardware).
* Copyright (C) 2000 Asit Mallick <Asit.K.Mallick@intel.com>
* Copyright (C) 2000 Goutham Rao <goutham.rao@intel.com>
* Copyright (C) 2000, 2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 03/05/07 davidm Switch from PCI-DMA to generic device DMA API.
* 00/12/13 davidm Rename to swiotlb.c and add mark_clean() to avoid
* unnecessary i-cache flushing.
* 04/07/.. ak Better overflow handling. Assorted fixes.
* 05/09/10 linville Add support for syncing ranges, support syncing for
* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
* 08/12/11 beckyb Add highmem support
*/
#define pr_fmt(fmt) "software IO TLB: " fmt
#include <linux/cache.h>
#include <linux/dma-direct.h>
#include <linux/dma-map-ops.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/swiotlb.h>
#include <linux/pfn.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/scatterlist.h>
#include <linux/mem_encrypt.h>
#include <linux/set_memory.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#endif
#include <asm/io.h>
#include <asm/dma.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/iommu-helper.h>
#define CREATE_TRACE_POINTS
#include <trace/events/swiotlb.h>
#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
/*
* Minimum IO TLB size to bother booting with. Systems with mainly
* 64bit capable cards will only lightly use the swiotlb. If we can't
* allocate a contiguous 1MB, we're probably in trouble anyway.
*/
#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
enum swiotlb_force swiotlb_force;
/*
* Used to do a quick range check in swiotlb_tbl_unmap_single and
* swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
* API.
*/
phys_addr_t io_tlb_start, io_tlb_end;
/*
* The number of IO TLB blocks (in groups of 64) between io_tlb_start and
* io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
*/
static unsigned long io_tlb_nslabs;
/*
* The number of used IO TLB block
*/
static unsigned long io_tlb_used;
/*
* This is a free list describing the number of free entries available from
* each index
*/
static unsigned int *io_tlb_list;
static unsigned int io_tlb_index;
/*
* Max segment that we can provide which (if pages are contingous) will
* not be bounced (unless SWIOTLB_FORCE is set).
*/
static unsigned int max_segment;
/*
* We need to save away the original address corresponding to a mapped entry
* for the sync operations.
*/
#define INVALID_PHYS_ADDR (~(phys_addr_t)0)
static phys_addr_t *io_tlb_orig_addr;
/*
* Protect the above data structures in the map and unmap calls
*/
static DEFINE_SPINLOCK(io_tlb_lock);
static int late_alloc;
static int __init
setup_io_tlb_npages(char *str)
{
if (isdigit(*str)) {
io_tlb_nslabs = simple_strtoul(str, &str, 0);
/* avoid tail segment of size < IO_TLB_SEGSIZE */
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
if (*str == ',')
++str;
if (!strcmp(str, "force")) {
swiotlb_force = SWIOTLB_FORCE;
} else if (!strcmp(str, "noforce")) {
swiotlb_force = SWIOTLB_NO_FORCE;
io_tlb_nslabs = 1;
}
return 0;
}
early_param("swiotlb", setup_io_tlb_npages);
static bool no_iotlb_memory;
unsigned long swiotlb_nr_tbl(void)
{
return unlikely(no_iotlb_memory) ? 0 : io_tlb_nslabs;
}
EXPORT_SYMBOL_GPL(swiotlb_nr_tbl);
unsigned int swiotlb_max_segment(void)
{
return unlikely(no_iotlb_memory) ? 0 : max_segment;
}
EXPORT_SYMBOL_GPL(swiotlb_max_segment);
void swiotlb_set_max_segment(unsigned int val)
{
if (swiotlb_force == SWIOTLB_FORCE)
max_segment = 1;
else
max_segment = rounddown(val, PAGE_SIZE);
}
/* default to 64MB */
#define IO_TLB_DEFAULT_SIZE (64UL<<20)
unsigned long swiotlb_size_or_default(void)
{
unsigned long size;
size = io_tlb_nslabs << IO_TLB_SHIFT;
return size ? size : (IO_TLB_DEFAULT_SIZE);
}
void swiotlb_print_info(void)
{
unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
if (no_iotlb_memory) {
pr_warn("No low mem\n");
return;
}
pr_info("mapped [mem %pa-%pa] (%luMB)\n", &io_tlb_start, &io_tlb_end,
bytes >> 20);
}
static inline unsigned long io_tlb_offset(unsigned long val)
{
return val & (IO_TLB_SEGSIZE - 1);
}
static inline unsigned long nr_slots(u64 val)
{
return DIV_ROUND_UP(val, IO_TLB_SIZE);
}
/*
* Early SWIOTLB allocation may be too early to allow an architecture to
* perform the desired operations. This function allows the architecture to
* call SWIOTLB when the operations are possible. It needs to be called
* before the SWIOTLB memory is used.
*/
void __init swiotlb_update_mem_attributes(void)
{
void *vaddr;
unsigned long bytes;
if (no_iotlb_memory || late_alloc)
return;
vaddr = phys_to_virt(io_tlb_start);
bytes = PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT);
set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
memset(vaddr, 0, bytes);
}
int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
{
unsigned long i, bytes;
size_t alloc_size;
bytes = nslabs << IO_TLB_SHIFT;
io_tlb_nslabs = nslabs;
io_tlb_start = __pa(tlb);
io_tlb_end = io_tlb_start + bytes;
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
* between io_tlb_start and io_tlb_end.
*/
alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int));
io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE);
if (!io_tlb_list)
panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
__func__, alloc_size, PAGE_SIZE);
alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t));
io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE);
if (!io_tlb_orig_addr)
panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
__func__, alloc_size, PAGE_SIZE);
for (i = 0; i < io_tlb_nslabs; i++) {
io_tlb_list[i] = IO_TLB_SEGSIZE - io_tlb_offset(i);
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
}
io_tlb_index = 0;
no_iotlb_memory = false;
if (verbose)
swiotlb_print_info();
swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT);
return 0;
}
/*
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
*/
void __init
swiotlb_init(int verbose)
{
size_t default_size = IO_TLB_DEFAULT_SIZE;
unsigned char *vstart;
unsigned long bytes;
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
/* Get IO TLB memory from the low pages */
vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE);
if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
return;
if (io_tlb_start) {
memblock_free_early(io_tlb_start,
PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
io_tlb_start = 0;
}
pr_warn("Cannot allocate buffer");
no_iotlb_memory = true;
}
/*
* Systems with larger DMA zones (those that don't support ISA) can
* initialize the swiotlb later using the slab allocator if needed.
* This should be just like above, but with some error catching.
*/
int
swiotlb_late_init_with_default_size(size_t default_size)
{
unsigned long bytes, req_nslabs = io_tlb_nslabs;
unsigned char *vstart = NULL;
unsigned int order;
int rc = 0;
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
}
/*
* Get IO TLB memory from the low pages
*/
order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
io_tlb_nslabs = SLABS_PER_PAGE << order;
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
vstart = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
order);
if (vstart)
break;
order--;
}
if (!vstart) {
io_tlb_nslabs = req_nslabs;
return -ENOMEM;
}
if (order != get_order(bytes)) {
pr_warn("only able to allocate %ld MB\n",
(PAGE_SIZE << order) >> 20);
io_tlb_nslabs = SLABS_PER_PAGE << order;
}
rc = swiotlb_late_init_with_tbl(vstart, io_tlb_nslabs);
if (rc)
free_pages((unsigned long)vstart, order);
return rc;
}
static void swiotlb_cleanup(void)
{
io_tlb_end = 0;
io_tlb_start = 0;
io_tlb_nslabs = 0;
max_segment = 0;
}
int
swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
{
unsigned long i, bytes;
bytes = nslabs << IO_TLB_SHIFT;
io_tlb_nslabs = nslabs;
io_tlb_start = virt_to_phys(tlb);
io_tlb_end = io_tlb_start + bytes;
set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
memset(tlb, 0, bytes);
/*
* Allocate and initialize the free list array. This array is used
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs * sizeof(int)));
if (!io_tlb_list)
goto cleanup3;
io_tlb_orig_addr = (phys_addr_t *)
__get_free_pages(GFP_KERNEL,
get_order(io_tlb_nslabs *
sizeof(phys_addr_t)));
if (!io_tlb_orig_addr)
goto cleanup4;
for (i = 0; i < io_tlb_nslabs; i++) {
io_tlb_list[i] = IO_TLB_SEGSIZE - io_tlb_offset(i);
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
}
io_tlb_index = 0;
no_iotlb_memory = false;
swiotlb_print_info();
late_alloc = 1;
swiotlb_set_max_segment(io_tlb_nslabs << IO_TLB_SHIFT);
return 0;
cleanup4:
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
sizeof(int)));
io_tlb_list = NULL;
cleanup3:
swiotlb_cleanup();
return -ENOMEM;
}
void __init swiotlb_exit(void)
{
if (!io_tlb_orig_addr)
return;
if (late_alloc) {
free_pages((unsigned long)io_tlb_orig_addr,
get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
sizeof(int)));
free_pages((unsigned long)phys_to_virt(io_tlb_start),
get_order(io_tlb_nslabs << IO_TLB_SHIFT));
} else {
memblock_free_late(__pa(io_tlb_orig_addr),
PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));
memblock_free_late(__pa(io_tlb_list),
PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
memblock_free_late(io_tlb_start,
PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
}
swiotlb_cleanup();
}
/*
* Bounce: copy the swiotlb buffer from or back to the original dma location
*/
static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir)
{
unsigned long pfn = PFN_DOWN(orig_addr);
unsigned char *vaddr = phys_to_virt(tlb_addr);
if (PageHighMem(pfn_to_page(pfn))) {
/* The buffer does not have a mapping. Map it in and copy */
unsigned int offset = orig_addr & ~PAGE_MASK;
char *buffer;
unsigned int sz = 0;
unsigned long flags;
while (size) {
sz = min_t(size_t, PAGE_SIZE - offset, size);
local_irq_save(flags);
buffer = kmap_atomic(pfn_to_page(pfn));
if (dir == DMA_TO_DEVICE)
memcpy(vaddr, buffer + offset, sz);
else
memcpy(buffer + offset, vaddr, sz);
kunmap_atomic(buffer);
local_irq_restore(flags);
size -= sz;
pfn++;
vaddr += sz;
offset = 0;
}
} else if (dir == DMA_TO_DEVICE) {
memcpy(vaddr, phys_to_virt(orig_addr), size);
} else {
memcpy(phys_to_virt(orig_addr), vaddr, size);
}
}
static inline phys_addr_t slot_addr(phys_addr_t start, phys_addr_t idx)
{
return start + (idx << IO_TLB_SHIFT);
}
/*
* Return the offset into a iotlb slot required to keep the device happy.
*/
static unsigned int swiotlb_align_offset(struct device *dev, u64 addr)
{
return addr & dma_get_min_align_mask(dev) & (IO_TLB_SIZE - 1);
}
/*
* Carefully handle integer overflow which can occur when boundary_mask == ~0UL.
*/
static inline unsigned long get_max_slots(unsigned long boundary_mask)
{
if (boundary_mask == ~0UL)
return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
return nr_slots(boundary_mask + 1);
}
static unsigned int wrap_index(unsigned int index)
{
if (index >= io_tlb_nslabs)
return 0;
return index;
}
/*
* Find a suitable number of IO TLB entries size that will fit this request and
* allocate a buffer from that IO TLB pool.
*/
static int find_slots(struct device *dev, phys_addr_t orig_addr,
size_t alloc_size)
{
unsigned long boundary_mask = dma_get_seg_boundary(dev);
dma_addr_t tbl_dma_addr =
phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask;
unsigned long max_slots = get_max_slots(boundary_mask);
unsigned int iotlb_align_mask =
dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
unsigned int nslots = nr_slots(alloc_size), stride;
unsigned int index, wrap, count = 0, i;
unsigned long flags;
BUG_ON(!nslots);
/*
* For mappings with an alignment requirement don't bother looping to
* unaligned slots once we found an aligned one. For allocations of
* PAGE_SIZE or larger only look for page aligned allocations.
*/
stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
if (alloc_size >= PAGE_SIZE)
stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT));
spin_lock_irqsave(&io_tlb_lock, flags);
if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
goto not_found;
index = wrap = wrap_index(ALIGN(io_tlb_index, stride));
do {
if ((slot_addr(tbl_dma_addr, index) & iotlb_align_mask) !=
(orig_addr & iotlb_align_mask)) {
index = wrap_index(index + 1);
continue;
}
/*
* If we find a slot that indicates we have 'nslots' number of
* contiguous buffers, we allocate the buffers from that slot
* and mark the entries as '0' indicating unavailable.
*/
if (!iommu_is_span_boundary(index, nslots,
nr_slots(tbl_dma_addr),
max_slots)) {
if (io_tlb_list[index] >= nslots)
goto found;
}
index = wrap_index(index + stride);
} while (index != wrap);
not_found:
spin_unlock_irqrestore(&io_tlb_lock, flags);
return -1;
found:
for (i = index; i < index + nslots; i++)
io_tlb_list[i] = 0;
for (i = index - 1;
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 &&
io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
/*
* Update the indices to avoid searching in the next round.
*/
if (index + nslots < io_tlb_nslabs)
io_tlb_index = index + nslots;
else
io_tlb_index = 0;
io_tlb_used += nslots;
spin_unlock_irqrestore(&io_tlb_lock, flags);
return index;
}
phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr,
size_t mapping_size, size_t alloc_size,
enum dma_data_direction dir, unsigned long attrs)
{
unsigned int offset = swiotlb_align_offset(dev, orig_addr);
unsigned int i;
int index;
phys_addr_t tlb_addr;
if (no_iotlb_memory)
panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
if (mem_encrypt_active())
pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n");
if (mapping_size > alloc_size) {
dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)",
mapping_size, alloc_size);
return (phys_addr_t)DMA_MAPPING_ERROR;
}
index = find_slots(dev, orig_addr, alloc_size + offset);
if (index == -1) {
if (!(attrs & DMA_ATTR_NO_WARN))
dev_warn_ratelimited(dev,
"swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
alloc_size, io_tlb_nslabs, io_tlb_used);
return (phys_addr_t)DMA_MAPPING_ERROR;
}
/*
* Save away the mapping from the original address to the DMA address.
* This is needed when we sync the memory. Then we sync the buffer if
* needed.
*/
for (i = 0; i < nr_slots(alloc_size + offset); i++)
io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i);
tlb_addr = slot_addr(io_tlb_start, index) + offset;
/*
* When dir == DMA_FROM_DEVICE we could omit the copy from the orig
* to the tlb buffer, if we knew for sure the device will
* overwirte the entire current content. But we don't. Thus
* unconditional bounce may prevent leaking swiotlb content (i.e.
* kernel memory) to user-space.
*/
swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE);
return tlb_addr;
}
/*
* tlb_addr is the physical address of the bounce buffer to unmap.
*/
void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
size_t mapping_size, size_t alloc_size,
enum dma_data_direction dir, unsigned long attrs)
{
unsigned long flags;
unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr);
int i, count, nslots = nr_slots(alloc_size + offset);
int index = (tlb_addr - offset - io_tlb_start) >> IO_TLB_SHIFT;
phys_addr_t orig_addr = io_tlb_orig_addr[index];
/*
* First, sync the memory before unmapping the entry
*/
if (orig_addr != INVALID_PHYS_ADDR &&
!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_FROM_DEVICE);
/*
* Return the buffer to the free list by setting the corresponding
* entries to indicate the number of contiguous entries available.
* While returning the entries to the free list, we merge the entries
* with slots below and above the pool being returned.
*/
spin_lock_irqsave(&io_tlb_lock, flags);
if (index + nslots < ALIGN(index + 1, IO_TLB_SEGSIZE))
count = io_tlb_list[index + nslots];
else
count = 0;
/*
* Step 1: return the slots to the free list, merging the slots with
* superceeding slots
*/
for (i = index + nslots - 1; i >= index; i--) {
io_tlb_list[i] = ++count;
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
}
/*
* Step 2: merge the returned slots with the preceding slots, if
* available (non zero)
*/
for (i = index - 1;
io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && io_tlb_list[i];
i--)
io_tlb_list[i] = ++count;
io_tlb_used -= nslots;
spin_unlock_irqrestore(&io_tlb_lock, flags);
}
void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
size_t size, enum dma_data_direction dir,
enum dma_sync_target target)
{
int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
phys_addr_t orig_addr = io_tlb_orig_addr[index];
if (orig_addr == INVALID_PHYS_ADDR)
return;
orig_addr += (tlb_addr & (IO_TLB_SIZE - 1)) -
swiotlb_align_offset(hwdev, orig_addr);
switch (target) {
case SYNC_FOR_CPU:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
swiotlb_bounce(orig_addr, tlb_addr,
size, DMA_FROM_DEVICE);
else
BUG_ON(dir != DMA_TO_DEVICE);
break;
case SYNC_FOR_DEVICE:
if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
swiotlb_bounce(orig_addr, tlb_addr,
size, DMA_TO_DEVICE);
else
BUG_ON(dir != DMA_FROM_DEVICE);
break;
default:
BUG();
}
}
/*
* Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing
* to the device copy the data into it as well.
*/
dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
phys_addr_t swiotlb_addr;
dma_addr_t dma_addr;
trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,
swiotlb_force);
swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, dir,
attrs);
if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
/* Ensure that the address returned is DMA'ble */
dma_addr = phys_to_dma_unencrypted(dev, swiotlb_addr);
if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, size, dir,
attrs | DMA_ATTR_SKIP_CPU_SYNC);
dev_WARN_ONCE(dev, 1,
"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
return DMA_MAPPING_ERROR;
}
if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))
arch_sync_dma_for_device(swiotlb_addr, size, dir);
return dma_addr;
}
size_t swiotlb_max_mapping_size(struct device *dev)
{
return ((size_t)IO_TLB_SIZE) * IO_TLB_SEGSIZE;
}
bool is_swiotlb_active(void)
{
/*
* When SWIOTLB is initialized, even if io_tlb_start points to physical
* address zero, io_tlb_end surely doesn't.
*/
return io_tlb_end != 0;
}
#ifdef CONFIG_DEBUG_FS
static int __init swiotlb_create_debugfs(void)
{
struct dentry *root;
root = debugfs_create_dir("swiotlb", NULL);
debugfs_create_ulong("io_tlb_nslabs", 0400, root, &io_tlb_nslabs);
debugfs_create_ulong("io_tlb_used", 0400, root, &io_tlb_used);
return 0;
}
late_initcall(swiotlb_create_debugfs);
#endif
|