1 /* 2 * Machine specific setup for xen 3 * 4 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 5 */ 6 7 #include <linux/init.h> 8 #include <linux/sched.h> 9 #include <linux/mm.h> 10 #include <linux/pm.h> 11 #include <linux/memblock.h> 12 #include <linux/cpuidle.h> 13 #include <linux/cpufreq.h> 14 15 #include <asm/elf.h> 16 #include <asm/vdso.h> 17 #include <asm/e820/api.h> 18 #include <asm/setup.h> 19 #include <asm/acpi.h> 20 #include <asm/numa.h> 21 #include <asm/xen/hypervisor.h> 22 #include <asm/xen/hypercall.h> 23 24 #include <xen/xen.h> 25 #include <xen/page.h> 26 #include <xen/interface/callback.h> 27 #include <xen/interface/memory.h> 28 #include <xen/interface/physdev.h> 29 #include <xen/features.h> 30 #include <xen/hvc-console.h> 31 #include "xen-ops.h" 32 #include "vdso.h" 33 #include "mmu.h" 34 35 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) 36 37 /* Amount of extra memory space we add to the e820 ranges */ 38 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; 39 40 /* Number of pages released from the initial allocation. */ 41 unsigned long xen_released_pages; 42 43 /* E820 map used during setting up memory. */ 44 static struct e820_table xen_e820_table __initdata; 45 46 /* 47 * Buffer used to remap identity mapped pages. We only need the virtual space. 48 * The physical page behind this address is remapped as needed to different 49 * buffer pages. 50 */ 51 #define REMAP_SIZE (P2M_PER_PAGE - 3) 52 static struct { 53 unsigned long next_area_mfn; 54 unsigned long target_pfn; 55 unsigned long size; 56 unsigned long mfns[REMAP_SIZE]; 57 } xen_remap_buf __initdata __aligned(PAGE_SIZE); 58 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; 59 60 /* 61 * The maximum amount of extra memory compared to the base size. The 62 * main scaling factor is the size of struct page. At extreme ratios 63 * of base:extra, all the base memory can be filled with page 64 * structures for the extra memory, leaving no space for anything 65 * else. 66 * 67 * 10x seems like a reasonable balance between scaling flexibility and 68 * leaving a practically usable system. 69 */ 70 #define EXTRA_MEM_RATIO (10) 71 72 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); 73 74 static void __init xen_parse_512gb(void) 75 { 76 bool val = false; 77 char *arg; 78 79 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); 80 if (!arg) 81 return; 82 83 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); 84 if (!arg) 85 val = true; 86 else if (strtobool(arg + strlen("xen_512gb_limit="), &val)) 87 return; 88 89 xen_512gb_limit = val; 90 } 91 92 static void __init xen_add_extra_mem(unsigned long start_pfn, 93 unsigned long n_pfns) 94 { 95 int i; 96 97 /* 98 * No need to check for zero size, should happen rarely and will only 99 * write a new entry regarded to be unused due to zero size. 100 */ 101 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 102 /* Add new region. */ 103 if (xen_extra_mem[i].n_pfns == 0) { 104 xen_extra_mem[i].start_pfn = start_pfn; 105 xen_extra_mem[i].n_pfns = n_pfns; 106 break; 107 } 108 /* Append to existing region. */ 109 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns == 110 start_pfn) { 111 xen_extra_mem[i].n_pfns += n_pfns; 112 break; 113 } 114 } 115 if (i == XEN_EXTRA_MEM_MAX_REGIONS) 116 printk(KERN_WARNING "Warning: not enough extra memory regions\n"); 117 118 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 119 } 120 121 static void __init xen_del_extra_mem(unsigned long start_pfn, 122 unsigned long n_pfns) 123 { 124 int i; 125 unsigned long start_r, size_r; 126 127 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 128 start_r = xen_extra_mem[i].start_pfn; 129 size_r = xen_extra_mem[i].n_pfns; 130 131 /* Start of region. */ 132 if (start_r == start_pfn) { 133 BUG_ON(n_pfns > size_r); 134 xen_extra_mem[i].start_pfn += n_pfns; 135 xen_extra_mem[i].n_pfns -= n_pfns; 136 break; 137 } 138 /* End of region. */ 139 if (start_r + size_r == start_pfn + n_pfns) { 140 BUG_ON(n_pfns > size_r); 141 xen_extra_mem[i].n_pfns -= n_pfns; 142 break; 143 } 144 /* Mid of region. */ 145 if (start_pfn > start_r && start_pfn < start_r + size_r) { 146 BUG_ON(start_pfn + n_pfns > start_r + size_r); 147 xen_extra_mem[i].n_pfns = start_pfn - start_r; 148 /* Calling memblock_reserve() again is okay. */ 149 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - 150 (start_pfn + n_pfns)); 151 break; 152 } 153 } 154 memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); 155 } 156 157 /* 158 * Called during boot before the p2m list can take entries beyond the 159 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as 160 * invalid. 161 */ 162 unsigned long __ref xen_chk_extra_mem(unsigned long pfn) 163 { 164 int i; 165 166 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 167 if (pfn >= xen_extra_mem[i].start_pfn && 168 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) 169 return INVALID_P2M_ENTRY; 170 } 171 172 return IDENTITY_FRAME(pfn); 173 } 174 175 /* 176 * Mark all pfns of extra mem as invalid in p2m list. 177 */ 178 void __init xen_inv_extra_mem(void) 179 { 180 unsigned long pfn, pfn_s, pfn_e; 181 int i; 182 183 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { 184 if (!xen_extra_mem[i].n_pfns) 185 continue; 186 pfn_s = xen_extra_mem[i].start_pfn; 187 pfn_e = pfn_s + xen_extra_mem[i].n_pfns; 188 for (pfn = pfn_s; pfn < pfn_e; pfn++) 189 set_phys_to_machine(pfn, INVALID_P2M_ENTRY); 190 } 191 } 192 193 /* 194 * Finds the next RAM pfn available in the E820 map after min_pfn. 195 * This function updates min_pfn with the pfn found and returns 196 * the size of that range or zero if not found. 197 */ 198 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn) 199 { 200 const struct e820_entry *entry = xen_e820_table.entries; 201 unsigned int i; 202 unsigned long done = 0; 203 204 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 205 unsigned long s_pfn; 206 unsigned long e_pfn; 207 208 if (entry->type != E820_TYPE_RAM) 209 continue; 210 211 e_pfn = PFN_DOWN(entry->addr + entry->size); 212 213 /* We only care about E820 after this */ 214 if (e_pfn <= *min_pfn) 215 continue; 216 217 s_pfn = PFN_UP(entry->addr); 218 219 /* If min_pfn falls within the E820 entry, we want to start 220 * at the min_pfn PFN. 221 */ 222 if (s_pfn <= *min_pfn) { 223 done = e_pfn - *min_pfn; 224 } else { 225 done = e_pfn - s_pfn; 226 *min_pfn = s_pfn; 227 } 228 break; 229 } 230 231 return done; 232 } 233 234 static int __init xen_free_mfn(unsigned long mfn) 235 { 236 struct xen_memory_reservation reservation = { 237 .address_bits = 0, 238 .extent_order = 0, 239 .domid = DOMID_SELF 240 }; 241 242 set_xen_guest_handle(reservation.extent_start, &mfn); 243 reservation.nr_extents = 1; 244 245 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); 246 } 247 248 /* 249 * This releases a chunk of memory and then does the identity map. It's used 250 * as a fallback if the remapping fails. 251 */ 252 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, 253 unsigned long end_pfn, unsigned long nr_pages) 254 { 255 unsigned long pfn, end; 256 int ret; 257 258 WARN_ON(start_pfn > end_pfn); 259 260 /* Release pages first. */ 261 end = min(end_pfn, nr_pages); 262 for (pfn = start_pfn; pfn < end; pfn++) { 263 unsigned long mfn = pfn_to_mfn(pfn); 264 265 /* Make sure pfn exists to start with */ 266 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) 267 continue; 268 269 ret = xen_free_mfn(mfn); 270 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); 271 272 if (ret == 1) { 273 xen_released_pages++; 274 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) 275 break; 276 } else 277 break; 278 } 279 280 set_phys_range_identity(start_pfn, end_pfn); 281 } 282 283 /* 284 * Helper function to update the p2m and m2p tables and kernel mapping. 285 */ 286 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn) 287 { 288 struct mmu_update update = { 289 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE, 290 .val = pfn 291 }; 292 293 /* Update p2m */ 294 if (!set_phys_to_machine(pfn, mfn)) { 295 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", 296 pfn, mfn); 297 BUG(); 298 } 299 300 /* Update m2p */ 301 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) { 302 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n", 303 mfn, pfn); 304 BUG(); 305 } 306 307 /* Update kernel mapping, but not for highmem. */ 308 if (pfn >= PFN_UP(__pa(high_memory - 1))) 309 return; 310 311 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), 312 mfn_pte(mfn, PAGE_KERNEL), 0)) { 313 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", 314 mfn, pfn); 315 BUG(); 316 } 317 } 318 319 /* 320 * This function updates the p2m and m2p tables with an identity map from 321 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the 322 * original allocation at remap_pfn. The information needed for remapping is 323 * saved in the memory itself to avoid the need for allocating buffers. The 324 * complete remap information is contained in a list of MFNs each containing 325 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap. 326 * This enables us to preserve the original mfn sequence while doing the 327 * remapping at a time when the memory management is capable of allocating 328 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and 329 * its callers. 330 */ 331 static void __init xen_do_set_identity_and_remap_chunk( 332 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn) 333 { 334 unsigned long buf = (unsigned long)&xen_remap_buf; 335 unsigned long mfn_save, mfn; 336 unsigned long ident_pfn_iter, remap_pfn_iter; 337 unsigned long ident_end_pfn = start_pfn + size; 338 unsigned long left = size; 339 unsigned int i, chunk; 340 341 WARN_ON(size == 0); 342 343 BUG_ON(xen_feature(XENFEAT_auto_translated_physmap)); 344 345 mfn_save = virt_to_mfn(buf); 346 347 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn; 348 ident_pfn_iter < ident_end_pfn; 349 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) { 350 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE; 351 352 /* Map first pfn to xen_remap_buf */ 353 mfn = pfn_to_mfn(ident_pfn_iter); 354 set_pte_mfn(buf, mfn, PAGE_KERNEL); 355 356 /* Save mapping information in page */ 357 xen_remap_buf.next_area_mfn = xen_remap_mfn; 358 xen_remap_buf.target_pfn = remap_pfn_iter; 359 xen_remap_buf.size = chunk; 360 for (i = 0; i < chunk; i++) 361 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i); 362 363 /* Put remap buf into list. */ 364 xen_remap_mfn = mfn; 365 366 /* Set identity map */ 367 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk); 368 369 left -= chunk; 370 } 371 372 /* Restore old xen_remap_buf mapping */ 373 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 374 } 375 376 /* 377 * This function takes a contiguous pfn range that needs to be identity mapped 378 * and: 379 * 380 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn. 381 * 2) Calls the do_ function to actually do the mapping/remapping work. 382 * 383 * The goal is to not allocate additional memory but to remap the existing 384 * pages. In the case of an error the underlying memory is simply released back 385 * to Xen and not remapped. 386 */ 387 static unsigned long __init xen_set_identity_and_remap_chunk( 388 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, 389 unsigned long remap_pfn) 390 { 391 unsigned long pfn; 392 unsigned long i = 0; 393 unsigned long n = end_pfn - start_pfn; 394 395 if (remap_pfn == 0) 396 remap_pfn = nr_pages; 397 398 while (i < n) { 399 unsigned long cur_pfn = start_pfn + i; 400 unsigned long left = n - i; 401 unsigned long size = left; 402 unsigned long remap_range_size; 403 404 /* Do not remap pages beyond the current allocation */ 405 if (cur_pfn >= nr_pages) { 406 /* Identity map remaining pages */ 407 set_phys_range_identity(cur_pfn, cur_pfn + size); 408 break; 409 } 410 if (cur_pfn + size > nr_pages) 411 size = nr_pages - cur_pfn; 412 413 remap_range_size = xen_find_pfn_range(&remap_pfn); 414 if (!remap_range_size) { 415 pr_warning("Unable to find available pfn range, not remapping identity pages\n"); 416 xen_set_identity_and_release_chunk(cur_pfn, 417 cur_pfn + left, nr_pages); 418 break; 419 } 420 /* Adjust size to fit in current e820 RAM region */ 421 if (size > remap_range_size) 422 size = remap_range_size; 423 424 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn); 425 426 /* Update variables to reflect new mappings. */ 427 i += size; 428 remap_pfn += size; 429 } 430 431 /* 432 * If the PFNs are currently mapped, the VA mapping also needs 433 * to be updated to be 1:1. 434 */ 435 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) 436 (void)HYPERVISOR_update_va_mapping( 437 (unsigned long)__va(pfn << PAGE_SHIFT), 438 mfn_pte(pfn, PAGE_KERNEL_IO), 0); 439 440 return remap_pfn; 441 } 442 443 static unsigned long __init xen_count_remap_pages( 444 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, 445 unsigned long remap_pages) 446 { 447 if (start_pfn >= nr_pages) 448 return remap_pages; 449 450 return remap_pages + min(end_pfn, nr_pages) - start_pfn; 451 } 452 453 static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, 454 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, 455 unsigned long nr_pages, unsigned long last_val)) 456 { 457 phys_addr_t start = 0; 458 unsigned long ret_val = 0; 459 const struct e820_entry *entry = xen_e820_table.entries; 460 int i; 461 462 /* 463 * Combine non-RAM regions and gaps until a RAM region (or the 464 * end of the map) is reached, then call the provided function 465 * to perform its duty on the non-RAM region. 466 * 467 * The combined non-RAM regions are rounded to a whole number 468 * of pages so any partial pages are accessible via the 1:1 469 * mapping. This is needed for some BIOSes that put (for 470 * example) the DMI tables in a reserved region that begins on 471 * a non-page boundary. 472 */ 473 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 474 phys_addr_t end = entry->addr + entry->size; 475 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) { 476 unsigned long start_pfn = PFN_DOWN(start); 477 unsigned long end_pfn = PFN_UP(end); 478 479 if (entry->type == E820_TYPE_RAM) 480 end_pfn = PFN_UP(entry->addr); 481 482 if (start_pfn < end_pfn) 483 ret_val = func(start_pfn, end_pfn, nr_pages, 484 ret_val); 485 start = end; 486 } 487 } 488 489 return ret_val; 490 } 491 492 /* 493 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk(). 494 * The remap information (which mfn remap to which pfn) is contained in the 495 * to be remapped memory itself in a linked list anchored at xen_remap_mfn. 496 * This scheme allows to remap the different chunks in arbitrary order while 497 * the resulting mapping will be independant from the order. 498 */ 499 void __init xen_remap_memory(void) 500 { 501 unsigned long buf = (unsigned long)&xen_remap_buf; 502 unsigned long mfn_save, mfn, pfn; 503 unsigned long remapped = 0; 504 unsigned int i; 505 unsigned long pfn_s = ~0UL; 506 unsigned long len = 0; 507 508 mfn_save = virt_to_mfn(buf); 509 510 while (xen_remap_mfn != INVALID_P2M_ENTRY) { 511 /* Map the remap information */ 512 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL); 513 514 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]); 515 516 pfn = xen_remap_buf.target_pfn; 517 for (i = 0; i < xen_remap_buf.size; i++) { 518 mfn = xen_remap_buf.mfns[i]; 519 xen_update_mem_tables(pfn, mfn); 520 remapped++; 521 pfn++; 522 } 523 if (pfn_s == ~0UL || pfn == pfn_s) { 524 pfn_s = xen_remap_buf.target_pfn; 525 len += xen_remap_buf.size; 526 } else if (pfn_s + len == xen_remap_buf.target_pfn) { 527 len += xen_remap_buf.size; 528 } else { 529 xen_del_extra_mem(pfn_s, len); 530 pfn_s = xen_remap_buf.target_pfn; 531 len = xen_remap_buf.size; 532 } 533 534 mfn = xen_remap_mfn; 535 xen_remap_mfn = xen_remap_buf.next_area_mfn; 536 } 537 538 if (pfn_s != ~0UL && len) 539 xen_del_extra_mem(pfn_s, len); 540 541 set_pte_mfn(buf, mfn_save, PAGE_KERNEL); 542 543 pr_info("Remapped %ld page(s)\n", remapped); 544 } 545 546 static unsigned long __init xen_get_pages_limit(void) 547 { 548 unsigned long limit; 549 550 #ifdef CONFIG_X86_32 551 limit = GB(64) / PAGE_SIZE; 552 #else 553 limit = MAXMEM / PAGE_SIZE; 554 if (!xen_initial_domain() && xen_512gb_limit) 555 limit = GB(512) / PAGE_SIZE; 556 #endif 557 return limit; 558 } 559 560 static unsigned long __init xen_get_max_pages(void) 561 { 562 unsigned long max_pages, limit; 563 domid_t domid = DOMID_SELF; 564 long ret; 565 566 limit = xen_get_pages_limit(); 567 max_pages = limit; 568 569 /* 570 * For the initial domain we use the maximum reservation as 571 * the maximum page. 572 * 573 * For guest domains the current maximum reservation reflects 574 * the current maximum rather than the static maximum. In this 575 * case the e820 map provided to us will cover the static 576 * maximum region. 577 */ 578 if (xen_initial_domain()) { 579 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); 580 if (ret > 0) 581 max_pages = ret; 582 } 583 584 return min(max_pages, limit); 585 } 586 587 static void __init xen_align_and_add_e820_region(phys_addr_t start, 588 phys_addr_t size, int type) 589 { 590 phys_addr_t end = start + size; 591 592 /* Align RAM regions to page boundaries. */ 593 if (type == E820_TYPE_RAM) { 594 start = PAGE_ALIGN(start); 595 end &= ~((phys_addr_t)PAGE_SIZE - 1); 596 } 597 598 e820__range_add(start, end - start, type); 599 } 600 601 static void __init xen_ignore_unusable(void) 602 { 603 struct e820_entry *entry = xen_e820_table.entries; 604 unsigned int i; 605 606 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { 607 if (entry->type == E820_TYPE_UNUSABLE) 608 entry->type = E820_TYPE_RAM; 609 } 610 } 611 612 bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) 613 { 614 struct e820_entry *entry; 615 unsigned mapcnt; 616 phys_addr_t end; 617 618 if (!size) 619 return false; 620 621 end = start + size; 622 entry = xen_e820_table.entries; 623 624 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { 625 if (entry->type == E820_TYPE_RAM && entry->addr <= start && 626 (entry->addr + entry->size) >= end) 627 return false; 628 629 entry++; 630 } 631 632 return true; 633 } 634 635 /* 636 * Find a free area in physical memory not yet reserved and compliant with 637 * E820 map. 638 * Used to relocate pre-allocated areas like initrd or p2m list which are in 639 * conflict with the to be used E820 map. 640 * In case no area is found, return 0. Otherwise return the physical address 641 * of the area which is already reserved for convenience. 642 */ 643 phys_addr_t __init xen_find_free_area(phys_addr_t size) 644 { 645 unsigned mapcnt; 646 phys_addr_t addr, start; 647 struct e820_entry *entry = xen_e820_table.entries; 648 649 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) { 650 if (entry->type != E820_TYPE_RAM || entry->size < size) 651 continue; 652 start = entry->addr; 653 for (addr = start; addr < start + size; addr += PAGE_SIZE) { 654 if (!memblock_is_reserved(addr)) 655 continue; 656 start = addr + PAGE_SIZE; 657 if (start + size > entry->addr + entry->size) 658 break; 659 } 660 if (addr >= start + size) { 661 memblock_reserve(start, size); 662 return start; 663 } 664 } 665 666 return 0; 667 } 668 669 /* 670 * Like memcpy, but with physical addresses for dest and src. 671 */ 672 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src, 673 phys_addr_t n) 674 { 675 phys_addr_t dest_off, src_off, dest_len, src_len, len; 676 void *from, *to; 677 678 while (n) { 679 dest_off = dest & ~PAGE_MASK; 680 src_off = src & ~PAGE_MASK; 681 dest_len = n; 682 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off) 683 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off; 684 src_len = n; 685 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off) 686 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off; 687 len = min(dest_len, src_len); 688 to = early_memremap(dest - dest_off, dest_len + dest_off); 689 from = early_memremap(src - src_off, src_len + src_off); 690 memcpy(to, from, len); 691 early_memunmap(to, dest_len + dest_off); 692 early_memunmap(from, src_len + src_off); 693 n -= len; 694 dest += len; 695 src += len; 696 } 697 } 698 699 /* 700 * Reserve Xen mfn_list. 701 */ 702 static void __init xen_reserve_xen_mfnlist(void) 703 { 704 phys_addr_t start, size; 705 706 if (xen_start_info->mfn_list >= __START_KERNEL_map) { 707 start = __pa(xen_start_info->mfn_list); 708 size = PFN_ALIGN(xen_start_info->nr_pages * 709 sizeof(unsigned long)); 710 } else { 711 start = PFN_PHYS(xen_start_info->first_p2m_pfn); 712 size = PFN_PHYS(xen_start_info->nr_p2m_frames); 713 } 714 715 memblock_reserve(start, size); 716 if (!xen_is_e820_reserved(start, size)) 717 return; 718 719 #ifdef CONFIG_X86_32 720 /* 721 * Relocating the p2m on 32 bit system to an arbitrary virtual address 722 * is not supported, so just give up. 723 */ 724 xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n"); 725 BUG(); 726 #else 727 xen_relocate_p2m(); 728 memblock_free(start, size); 729 #endif 730 } 731 732 /** 733 * machine_specific_memory_setup - Hook for machine specific memory setup. 734 **/ 735 char * __init xen_memory_setup(void) 736 { 737 unsigned long max_pfn, pfn_s, n_pfns; 738 phys_addr_t mem_end, addr, size, chunk_size; 739 u32 type; 740 int rc; 741 struct xen_memory_map memmap; 742 unsigned long max_pages; 743 unsigned long extra_pages = 0; 744 int i; 745 int op; 746 747 xen_parse_512gb(); 748 max_pfn = xen_get_pages_limit(); 749 max_pfn = min(max_pfn, xen_start_info->nr_pages); 750 mem_end = PFN_PHYS(max_pfn); 751 752 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); 753 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); 754 755 op = xen_initial_domain() ? 756 XENMEM_machine_memory_map : 757 XENMEM_memory_map; 758 rc = HYPERVISOR_memory_op(op, &memmap); 759 if (rc == -ENOSYS) { 760 BUG_ON(xen_initial_domain()); 761 memmap.nr_entries = 1; 762 xen_e820_table.entries[0].addr = 0ULL; 763 xen_e820_table.entries[0].size = mem_end; 764 /* 8MB slack (to balance backend allocations). */ 765 xen_e820_table.entries[0].size += 8ULL << 20; 766 xen_e820_table.entries[0].type = E820_TYPE_RAM; 767 rc = 0; 768 } 769 BUG_ON(rc); 770 BUG_ON(memmap.nr_entries == 0); 771 xen_e820_table.nr_entries = memmap.nr_entries; 772 773 /* 774 * Xen won't allow a 1:1 mapping to be created to UNUSABLE 775 * regions, so if we're using the machine memory map leave the 776 * region as RAM as it is in the pseudo-physical map. 777 * 778 * UNUSABLE regions in domUs are not handled and will need 779 * a patch in the future. 780 */ 781 if (xen_initial_domain()) 782 xen_ignore_unusable(); 783 784 /* Make sure the Xen-supplied memory map is well-ordered. */ 785 e820__update_table(&xen_e820_table); 786 787 max_pages = xen_get_max_pages(); 788 789 /* How many extra pages do we need due to remapping? */ 790 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); 791 792 if (max_pages > max_pfn) 793 extra_pages += max_pages - max_pfn; 794 795 /* 796 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO 797 * factor the base size. On non-highmem systems, the base 798 * size is the full initial memory allocation; on highmem it 799 * is limited to the max size of lowmem, so that it doesn't 800 * get completely filled. 801 * 802 * Make sure we have no memory above max_pages, as this area 803 * isn't handled by the p2m management. 804 * 805 * In principle there could be a problem in lowmem systems if 806 * the initial memory is also very large with respect to 807 * lowmem, but we won't try to deal with that here. 808 */ 809 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), 810 extra_pages, max_pages - max_pfn); 811 i = 0; 812 addr = xen_e820_table.entries[0].addr; 813 size = xen_e820_table.entries[0].size; 814 while (i < xen_e820_table.nr_entries) { 815 bool discard = false; 816 817 chunk_size = size; 818 type = xen_e820_table.entries[i].type; 819 820 if (type == E820_TYPE_RAM) { 821 if (addr < mem_end) { 822 chunk_size = min(size, mem_end - addr); 823 } else if (extra_pages) { 824 chunk_size = min(size, PFN_PHYS(extra_pages)); 825 pfn_s = PFN_UP(addr); 826 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s; 827 extra_pages -= n_pfns; 828 xen_add_extra_mem(pfn_s, n_pfns); 829 xen_max_p2m_pfn = pfn_s + n_pfns; 830 } else 831 discard = true; 832 } 833 834 if (!discard) 835 xen_align_and_add_e820_region(addr, chunk_size, type); 836 837 addr += chunk_size; 838 size -= chunk_size; 839 if (size == 0) { 840 i++; 841 if (i < xen_e820_table.nr_entries) { 842 addr = xen_e820_table.entries[i].addr; 843 size = xen_e820_table.entries[i].size; 844 } 845 } 846 } 847 848 /* 849 * Set the rest as identity mapped, in case PCI BARs are 850 * located here. 851 */ 852 set_phys_range_identity(addr / PAGE_SIZE, ~0ul); 853 854 /* 855 * In domU, the ISA region is normal, usable memory, but we 856 * reserve ISA memory anyway because too many things poke 857 * about in there. 858 */ 859 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED); 860 861 e820__update_table(e820_table); 862 863 /* 864 * Check whether the kernel itself conflicts with the target E820 map. 865 * Failing now is better than running into weird problems later due 866 * to relocating (and even reusing) pages with kernel text or data. 867 */ 868 if (xen_is_e820_reserved(__pa_symbol(_text), 869 __pa_symbol(__bss_stop) - __pa_symbol(_text))) { 870 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); 871 BUG(); 872 } 873 874 /* 875 * Check for a conflict of the hypervisor supplied page tables with 876 * the target E820 map. 877 */ 878 xen_pt_check_e820(); 879 880 xen_reserve_xen_mfnlist(); 881 882 /* Check for a conflict of the initrd with the target E820 map. */ 883 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image, 884 boot_params.hdr.ramdisk_size)) { 885 phys_addr_t new_area, start, size; 886 887 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size); 888 if (!new_area) { 889 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n"); 890 BUG(); 891 } 892 893 start = boot_params.hdr.ramdisk_image; 894 size = boot_params.hdr.ramdisk_size; 895 xen_phys_memcpy(new_area, start, size); 896 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n", 897 start, start + size, new_area, new_area + size); 898 memblock_free(start, size); 899 boot_params.hdr.ramdisk_image = new_area; 900 boot_params.ext_ramdisk_image = new_area >> 32; 901 } 902 903 /* 904 * Set identity map on non-RAM pages and prepare remapping the 905 * underlying RAM. 906 */ 907 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk); 908 909 pr_info("Released %ld page(s)\n", xen_released_pages); 910 911 return "Xen"; 912 } 913 914 /* 915 * Machine specific memory setup for auto-translated guests. 916 */ 917 char * __init xen_auto_xlated_memory_setup(void) 918 { 919 struct xen_memory_map memmap; 920 int i; 921 int rc; 922 923 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); 924 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); 925 926 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap); 927 if (rc < 0) 928 panic("No memory map (%d)\n", rc); 929 930 xen_e820_table.nr_entries = memmap.nr_entries; 931 932 e820__update_table(&xen_e820_table); 933 934 for (i = 0; i < xen_e820_table.nr_entries; i++) 935 e820__range_add(xen_e820_table.entries[i].addr, xen_e820_table.entries[i].size, xen_e820_table.entries[i].type); 936 937 /* Remove p2m info, it is not needed. */ 938 xen_start_info->mfn_list = 0; 939 xen_start_info->first_p2m_pfn = 0; 940 xen_start_info->nr_p2m_frames = 0; 941 942 return "Xen"; 943 } 944 945 /* 946 * Set the bit indicating "nosegneg" library variants should be used. 947 * We only need to bother in pure 32-bit mode; compat 32-bit processes 948 * can have un-truncated segments, so wrapping around is allowed. 949 */ 950 static void __init fiddle_vdso(void) 951 { 952 #ifdef CONFIG_X86_32 953 u32 *mask = vdso_image_32.data + 954 vdso_image_32.sym_VDSO32_NOTE_MASK; 955 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT; 956 #endif 957 } 958 959 static int register_callback(unsigned type, const void *func) 960 { 961 struct callback_register callback = { 962 .type = type, 963 .address = XEN_CALLBACK(__KERNEL_CS, func), 964 .flags = CALLBACKF_mask_events, 965 }; 966 967 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); 968 } 969 970 void xen_enable_sysenter(void) 971 { 972 int ret; 973 unsigned sysenter_feature; 974 975 #ifdef CONFIG_X86_32 976 sysenter_feature = X86_FEATURE_SEP; 977 #else 978 sysenter_feature = X86_FEATURE_SYSENTER32; 979 #endif 980 981 if (!boot_cpu_has(sysenter_feature)) 982 return; 983 984 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target); 985 if(ret != 0) 986 setup_clear_cpu_cap(sysenter_feature); 987 } 988 989 void xen_enable_syscall(void) 990 { 991 #ifdef CONFIG_X86_64 992 int ret; 993 994 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target); 995 if (ret != 0) { 996 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); 997 /* Pretty fatal; 64-bit userspace has no other 998 mechanism for syscalls. */ 999 } 1000 1001 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) { 1002 ret = register_callback(CALLBACKTYPE_syscall32, 1003 xen_syscall32_target); 1004 if (ret != 0) 1005 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); 1006 } 1007 #endif /* CONFIG_X86_64 */ 1008 } 1009 1010 void __init xen_pvmmu_arch_setup(void) 1011 { 1012 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); 1013 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); 1014 1015 HYPERVISOR_vm_assist(VMASST_CMD_enable, 1016 VMASST_TYPE_pae_extended_cr3); 1017 1018 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) || 1019 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) 1020 BUG(); 1021 1022 xen_enable_sysenter(); 1023 xen_enable_syscall(); 1024 } 1025 1026 /* This function is not called for HVM domains */ 1027 void __init xen_arch_setup(void) 1028 { 1029 xen_panic_handler_init(); 1030 if (!xen_feature(XENFEAT_auto_translated_physmap)) 1031 xen_pvmmu_arch_setup(); 1032 1033 #ifdef CONFIG_ACPI 1034 if (!(xen_start_info->flags & SIF_INITDOMAIN)) { 1035 printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); 1036 disable_acpi(); 1037 } 1038 #endif 1039 1040 memcpy(boot_command_line, xen_start_info->cmd_line, 1041 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? 1042 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); 1043 1044 /* Set up idle, making sure it calls safe_halt() pvop */ 1045 disable_cpuidle(); 1046 disable_cpufreq(); 1047 WARN_ON(xen_set_default_idle()); 1048 fiddle_vdso(); 1049 #ifdef CONFIG_NUMA 1050 numa_off = 1; 1051 #endif 1052 } 1053