1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/parisc/mm/init.c 4 * 5 * Copyright (C) 1995 Linus Torvalds 6 * Copyright 1999 SuSE GmbH 7 * changed by Philipp Rumpf 8 * Copyright 1999 Philipp Rumpf (prumpf@tux.org) 9 * Copyright 2004 Randolph Chung (tausq@debian.org) 10 * Copyright 2006-2007 Helge Deller (deller@gmx.de) 11 * 12 */ 13 14 15 #include <linux/module.h> 16 #include <linux/mm.h> 17 #include <linux/memblock.h> 18 #include <linux/gfp.h> 19 #include <linux/delay.h> 20 #include <linux/init.h> 21 #include <linux/initrd.h> 22 #include <linux/swap.h> 23 #include <linux/unistd.h> 24 #include <linux/nodemask.h> /* for node_online_map */ 25 #include <linux/pagemap.h> /* for release_pages */ 26 #include <linux/compat.h> 27 28 #include <asm/pgalloc.h> 29 #include <asm/tlb.h> 30 #include <asm/pdc_chassis.h> 31 #include <asm/mmzone.h> 32 #include <asm/sections.h> 33 #include <asm/msgbuf.h> 34 #include <asm/sparsemem.h> 35 36 extern int data_start; 37 extern void parisc_kernel_start(void); /* Kernel entry point in head.S */ 38 39 #if CONFIG_PGTABLE_LEVELS == 3 40 pmd_t pmd0[PTRS_PER_PMD] __section(".data..vm0.pmd") __attribute__ ((aligned(PAGE_SIZE))); 41 #endif 42 43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".data..vm0.pgd") __attribute__ ((aligned(PAGE_SIZE))); 44 pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __section(".data..vm0.pte") __attribute__ ((aligned(PAGE_SIZE))); 45 46 static struct resource data_resource = { 47 .name = "Kernel data", 48 .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, 49 }; 50 51 static struct resource code_resource = { 52 .name = "Kernel code", 53 .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, 54 }; 55 56 static struct resource pdcdata_resource = { 57 .name = "PDC data (Page Zero)", 58 .start = 0, 59 .end = 0x9ff, 60 .flags = IORESOURCE_BUSY | IORESOURCE_MEM, 61 }; 62 63 static struct resource sysram_resources[MAX_PHYSMEM_RANGES] __ro_after_init; 64 65 /* The following array is initialized from the firmware specific 66 * information retrieved in kernel/inventory.c. 67 */ 68 69 physmem_range_t pmem_ranges[MAX_PHYSMEM_RANGES] __initdata; 70 int npmem_ranges __initdata; 71 72 #ifdef CONFIG_64BIT 73 #define MAX_MEM (1UL << MAX_PHYSMEM_BITS) 74 #else /* !CONFIG_64BIT */ 75 #define MAX_MEM (3584U*1024U*1024U) 76 #endif /* !CONFIG_64BIT */ 77 78 static unsigned long mem_limit __read_mostly = MAX_MEM; 79 80 static void __init mem_limit_func(void) 81 { 82 char *cp, *end; 83 unsigned long limit; 84 85 /* We need this before __setup() functions are called */ 86 87 limit = MAX_MEM; 88 for (cp = boot_command_line; *cp; ) { 89 if (memcmp(cp, "mem=", 4) == 0) { 90 cp += 4; 91 limit = memparse(cp, &end); 92 if (end != cp) 93 break; 94 cp = end; 95 } else { 96 while (*cp != ' ' && *cp) 97 ++cp; 98 while (*cp == ' ') 99 ++cp; 100 } 101 } 102 103 if (limit < mem_limit) 104 mem_limit = limit; 105 } 106 107 #define MAX_GAP (0x40000000UL >> PAGE_SHIFT) 108 109 static void __init setup_bootmem(void) 110 { 111 unsigned long mem_max; 112 #ifndef CONFIG_SPARSEMEM 113 physmem_range_t pmem_holes[MAX_PHYSMEM_RANGES - 1]; 114 int npmem_holes; 115 #endif 116 int i, sysram_resource_count; 117 118 disable_sr_hashing(); /* Turn off space register hashing */ 119 120 /* 121 * Sort the ranges. Since the number of ranges is typically 122 * small, and performance is not an issue here, just do 123 * a simple insertion sort. 124 */ 125 126 for (i = 1; i < npmem_ranges; i++) { 127 int j; 128 129 for (j = i; j > 0; j--) { 130 if (pmem_ranges[j-1].start_pfn < 131 pmem_ranges[j].start_pfn) { 132 133 break; 134 } 135 swap(pmem_ranges[j-1], pmem_ranges[j]); 136 } 137 } 138 139 #ifndef CONFIG_SPARSEMEM 140 /* 141 * Throw out ranges that are too far apart (controlled by 142 * MAX_GAP). 143 */ 144 145 for (i = 1; i < npmem_ranges; i++) { 146 if (pmem_ranges[i].start_pfn - 147 (pmem_ranges[i-1].start_pfn + 148 pmem_ranges[i-1].pages) > MAX_GAP) { 149 npmem_ranges = i; 150 printk("Large gap in memory detected (%ld pages). " 151 "Consider turning on CONFIG_SPARSEMEM\n", 152 pmem_ranges[i].start_pfn - 153 (pmem_ranges[i-1].start_pfn + 154 pmem_ranges[i-1].pages)); 155 break; 156 } 157 } 158 #endif 159 160 /* Print the memory ranges */ 161 pr_info("Memory Ranges:\n"); 162 163 for (i = 0; i < npmem_ranges; i++) { 164 struct resource *res = &sysram_resources[i]; 165 unsigned long start; 166 unsigned long size; 167 168 size = (pmem_ranges[i].pages << PAGE_SHIFT); 169 start = (pmem_ranges[i].start_pfn << PAGE_SHIFT); 170 pr_info("%2d) Start 0x%016lx End 0x%016lx Size %6ld MB\n", 171 i, start, start + (size - 1), size >> 20); 172 173 /* request memory resource */ 174 res->name = "System RAM"; 175 res->start = start; 176 res->end = start + size - 1; 177 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 178 request_resource(&iomem_resource, res); 179 } 180 181 sysram_resource_count = npmem_ranges; 182 183 /* 184 * For 32 bit kernels we limit the amount of memory we can 185 * support, in order to preserve enough kernel address space 186 * for other purposes. For 64 bit kernels we don't normally 187 * limit the memory, but this mechanism can be used to 188 * artificially limit the amount of memory (and it is written 189 * to work with multiple memory ranges). 190 */ 191 192 mem_limit_func(); /* check for "mem=" argument */ 193 194 mem_max = 0; 195 for (i = 0; i < npmem_ranges; i++) { 196 unsigned long rsize; 197 198 rsize = pmem_ranges[i].pages << PAGE_SHIFT; 199 if ((mem_max + rsize) > mem_limit) { 200 printk(KERN_WARNING "Memory truncated to %ld MB\n", mem_limit >> 20); 201 if (mem_max == mem_limit) 202 npmem_ranges = i; 203 else { 204 pmem_ranges[i].pages = (mem_limit >> PAGE_SHIFT) 205 - (mem_max >> PAGE_SHIFT); 206 npmem_ranges = i + 1; 207 mem_max = mem_limit; 208 } 209 break; 210 } 211 mem_max += rsize; 212 } 213 214 printk(KERN_INFO "Total Memory: %ld MB\n",mem_max >> 20); 215 216 #ifndef CONFIG_SPARSEMEM 217 /* Merge the ranges, keeping track of the holes */ 218 { 219 unsigned long end_pfn; 220 unsigned long hole_pages; 221 222 npmem_holes = 0; 223 end_pfn = pmem_ranges[0].start_pfn + pmem_ranges[0].pages; 224 for (i = 1; i < npmem_ranges; i++) { 225 226 hole_pages = pmem_ranges[i].start_pfn - end_pfn; 227 if (hole_pages) { 228 pmem_holes[npmem_holes].start_pfn = end_pfn; 229 pmem_holes[npmem_holes++].pages = hole_pages; 230 end_pfn += hole_pages; 231 } 232 end_pfn += pmem_ranges[i].pages; 233 } 234 235 pmem_ranges[0].pages = end_pfn - pmem_ranges[0].start_pfn; 236 npmem_ranges = 1; 237 } 238 #endif 239 240 /* 241 * Initialize and free the full range of memory in each range. 242 */ 243 244 max_pfn = 0; 245 for (i = 0; i < npmem_ranges; i++) { 246 unsigned long start_pfn; 247 unsigned long npages; 248 unsigned long start; 249 unsigned long size; 250 251 start_pfn = pmem_ranges[i].start_pfn; 252 npages = pmem_ranges[i].pages; 253 254 start = start_pfn << PAGE_SHIFT; 255 size = npages << PAGE_SHIFT; 256 257 /* add system RAM memblock */ 258 memblock_add(start, size); 259 260 if ((start_pfn + npages) > max_pfn) 261 max_pfn = start_pfn + npages; 262 } 263 264 /* 265 * We can't use memblock top-down allocations because we only 266 * created the initial mapping up to KERNEL_INITIAL_SIZE in 267 * the assembly bootup code. 268 */ 269 memblock_set_bottom_up(true); 270 271 /* IOMMU is always used to access "high mem" on those boxes 272 * that can support enough mem that a PCI device couldn't 273 * directly DMA to any physical addresses. 274 * ISA DMA support will need to revisit this. 275 */ 276 max_low_pfn = max_pfn; 277 278 /* reserve PAGE0 pdc memory, kernel text/data/bss & bootmap */ 279 280 #define PDC_CONSOLE_IO_IODC_SIZE 32768 281 282 memblock_reserve(0UL, (unsigned long)(PAGE0->mem_free + 283 PDC_CONSOLE_IO_IODC_SIZE)); 284 memblock_reserve(__pa(KERNEL_BINARY_TEXT_START), 285 (unsigned long)(_end - KERNEL_BINARY_TEXT_START)); 286 287 #ifndef CONFIG_SPARSEMEM 288 289 /* reserve the holes */ 290 291 for (i = 0; i < npmem_holes; i++) { 292 memblock_reserve((pmem_holes[i].start_pfn << PAGE_SHIFT), 293 (pmem_holes[i].pages << PAGE_SHIFT)); 294 } 295 #endif 296 297 #ifdef CONFIG_BLK_DEV_INITRD 298 if (initrd_start) { 299 printk(KERN_INFO "initrd: %08lx-%08lx\n", initrd_start, initrd_end); 300 if (__pa(initrd_start) < mem_max) { 301 unsigned long initrd_reserve; 302 303 if (__pa(initrd_end) > mem_max) { 304 initrd_reserve = mem_max - __pa(initrd_start); 305 } else { 306 initrd_reserve = initrd_end - initrd_start; 307 } 308 initrd_below_start_ok = 1; 309 printk(KERN_INFO "initrd: reserving %08lx-%08lx (mem_max %08lx)\n", __pa(initrd_start), __pa(initrd_start) + initrd_reserve, mem_max); 310 311 memblock_reserve(__pa(initrd_start), initrd_reserve); 312 } 313 } 314 #endif 315 316 data_resource.start = virt_to_phys(&data_start); 317 data_resource.end = virt_to_phys(_end) - 1; 318 code_resource.start = virt_to_phys(_text); 319 code_resource.end = virt_to_phys(&data_start)-1; 320 321 /* We don't know which region the kernel will be in, so try 322 * all of them. 323 */ 324 for (i = 0; i < sysram_resource_count; i++) { 325 struct resource *res = &sysram_resources[i]; 326 request_resource(res, &code_resource); 327 request_resource(res, &data_resource); 328 } 329 request_resource(&sysram_resources[0], &pdcdata_resource); 330 331 /* Initialize Page Deallocation Table (PDT) and check for bad memory. */ 332 pdc_pdt_init(); 333 334 memblock_allow_resize(); 335 memblock_dump_all(); 336 } 337 338 static bool kernel_set_to_readonly; 339 340 static void __ref map_pages(unsigned long start_vaddr, 341 unsigned long start_paddr, unsigned long size, 342 pgprot_t pgprot, int force) 343 { 344 pmd_t *pmd; 345 pte_t *pg_table; 346 unsigned long end_paddr; 347 unsigned long start_pmd; 348 unsigned long start_pte; 349 unsigned long tmp1; 350 unsigned long tmp2; 351 unsigned long address; 352 unsigned long vaddr; 353 unsigned long ro_start; 354 unsigned long ro_end; 355 unsigned long kernel_start, kernel_end; 356 357 ro_start = __pa((unsigned long)_text); 358 ro_end = __pa((unsigned long)&data_start); 359 kernel_start = __pa((unsigned long)&__init_begin); 360 kernel_end = __pa((unsigned long)&_end); 361 362 end_paddr = start_paddr + size; 363 364 /* for 2-level configuration PTRS_PER_PMD is 0 so start_pmd will be 0 */ 365 start_pmd = ((start_vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1)); 366 start_pte = ((start_vaddr >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)); 367 368 address = start_paddr; 369 vaddr = start_vaddr; 370 while (address < end_paddr) { 371 pgd_t *pgd = pgd_offset_k(vaddr); 372 p4d_t *p4d = p4d_offset(pgd, vaddr); 373 pud_t *pud = pud_offset(p4d, vaddr); 374 375 #if CONFIG_PGTABLE_LEVELS == 3 376 if (pud_none(*pud)) { 377 pmd = memblock_alloc(PAGE_SIZE << PMD_TABLE_ORDER, 378 PAGE_SIZE << PMD_TABLE_ORDER); 379 if (!pmd) 380 panic("pmd allocation failed.\n"); 381 pud_populate(NULL, pud, pmd); 382 } 383 #endif 384 385 pmd = pmd_offset(pud, vaddr); 386 for (tmp1 = start_pmd; tmp1 < PTRS_PER_PMD; tmp1++, pmd++) { 387 if (pmd_none(*pmd)) { 388 pg_table = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 389 if (!pg_table) 390 panic("page table allocation failed\n"); 391 pmd_populate_kernel(NULL, pmd, pg_table); 392 } 393 394 pg_table = pte_offset_kernel(pmd, vaddr); 395 for (tmp2 = start_pte; tmp2 < PTRS_PER_PTE; tmp2++, pg_table++) { 396 pte_t pte; 397 pgprot_t prot; 398 bool huge = false; 399 400 if (force) { 401 prot = pgprot; 402 } else if (address < kernel_start || address >= kernel_end) { 403 /* outside kernel memory */ 404 prot = PAGE_KERNEL; 405 } else if (!kernel_set_to_readonly) { 406 /* still initializing, allow writing to RO memory */ 407 prot = PAGE_KERNEL_RWX; 408 huge = true; 409 } else if (address >= ro_start) { 410 /* Code (ro) and Data areas */ 411 prot = (address < ro_end) ? 412 PAGE_KERNEL_EXEC : PAGE_KERNEL; 413 huge = true; 414 } else { 415 prot = PAGE_KERNEL; 416 } 417 418 pte = __mk_pte(address, prot); 419 if (huge) 420 pte = pte_mkhuge(pte); 421 422 if (address >= end_paddr) 423 break; 424 425 set_pte(pg_table, pte); 426 427 address += PAGE_SIZE; 428 vaddr += PAGE_SIZE; 429 } 430 start_pte = 0; 431 432 if (address >= end_paddr) 433 break; 434 } 435 start_pmd = 0; 436 } 437 } 438 439 void __init set_kernel_text_rw(int enable_read_write) 440 { 441 unsigned long start = (unsigned long) __init_begin; 442 unsigned long end = (unsigned long) &data_start; 443 444 map_pages(start, __pa(start), end-start, 445 PAGE_KERNEL_RWX, enable_read_write ? 1:0); 446 447 /* force the kernel to see the new page table entries */ 448 flush_cache_all(); 449 flush_tlb_all(); 450 } 451 452 void free_initmem(void) 453 { 454 unsigned long init_begin = (unsigned long)__init_begin; 455 unsigned long init_end = (unsigned long)__init_end; 456 unsigned long kernel_end = (unsigned long)&_end; 457 458 /* Remap kernel text and data, but do not touch init section yet. */ 459 kernel_set_to_readonly = true; 460 map_pages(init_end, __pa(init_end), kernel_end - init_end, 461 PAGE_KERNEL, 0); 462 463 /* The init text pages are marked R-X. We have to 464 * flush the icache and mark them RW- 465 * 466 * Do a dummy remap of the data section first (the data 467 * section is already PAGE_KERNEL) to pull in the TLB entries 468 * for map_kernel */ 469 map_pages(init_begin, __pa(init_begin), init_end - init_begin, 470 PAGE_KERNEL_RWX, 1); 471 /* now remap at PAGE_KERNEL since the TLB is pre-primed to execute 472 * map_pages */ 473 map_pages(init_begin, __pa(init_begin), init_end - init_begin, 474 PAGE_KERNEL, 1); 475 476 /* force the kernel to see the new TLB entries */ 477 __flush_tlb_range(0, init_begin, kernel_end); 478 479 /* finally dump all the instructions which were cached, since the 480 * pages are no-longer executable */ 481 flush_icache_range(init_begin, init_end); 482 483 free_initmem_default(POISON_FREE_INITMEM); 484 485 /* set up a new led state on systems shipped LED State panel */ 486 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_BCOMPLETE); 487 } 488 489 490 #ifdef CONFIG_STRICT_KERNEL_RWX 491 void mark_rodata_ro(void) 492 { 493 /* rodata memory was already mapped with KERNEL_RO access rights by 494 pagetable_init() and map_pages(). No need to do additional stuff here */ 495 unsigned long roai_size = __end_ro_after_init - __start_ro_after_init; 496 497 pr_info("Write protected read-only-after-init data: %luk\n", roai_size >> 10); 498 } 499 #endif 500 501 502 /* 503 * Just an arbitrary offset to serve as a "hole" between mapping areas 504 * (between top of physical memory and a potential pcxl dma mapping 505 * area, and below the vmalloc mapping area). 506 * 507 * The current 32K value just means that there will be a 32K "hole" 508 * between mapping areas. That means that any out-of-bounds memory 509 * accesses will hopefully be caught. The vmalloc() routines leaves 510 * a hole of 4kB between each vmalloced area for the same reason. 511 */ 512 513 /* Leave room for gateway page expansion */ 514 #if KERNEL_MAP_START < GATEWAY_PAGE_SIZE 515 #error KERNEL_MAP_START is in gateway reserved region 516 #endif 517 #define MAP_START (KERNEL_MAP_START) 518 519 #define VM_MAP_OFFSET (32*1024) 520 #define SET_MAP_OFFSET(x) ((void *)(((unsigned long)(x) + VM_MAP_OFFSET) \ 521 & ~(VM_MAP_OFFSET-1))) 522 523 void *parisc_vmalloc_start __ro_after_init; 524 EXPORT_SYMBOL(parisc_vmalloc_start); 525 526 #ifdef CONFIG_PA11 527 unsigned long pcxl_dma_start __ro_after_init; 528 #endif 529 530 void __init mem_init(void) 531 { 532 /* Do sanity checks on IPC (compat) structures */ 533 BUILD_BUG_ON(sizeof(struct ipc64_perm) != 48); 534 #ifndef CONFIG_64BIT 535 BUILD_BUG_ON(sizeof(struct semid64_ds) != 80); 536 BUILD_BUG_ON(sizeof(struct msqid64_ds) != 104); 537 BUILD_BUG_ON(sizeof(struct shmid64_ds) != 104); 538 #endif 539 #ifdef CONFIG_COMPAT 540 BUILD_BUG_ON(sizeof(struct compat_ipc64_perm) != sizeof(struct ipc64_perm)); 541 BUILD_BUG_ON(sizeof(struct compat_semid64_ds) != 80); 542 BUILD_BUG_ON(sizeof(struct compat_msqid64_ds) != 104); 543 BUILD_BUG_ON(sizeof(struct compat_shmid64_ds) != 104); 544 #endif 545 546 /* Do sanity checks on page table constants */ 547 BUILD_BUG_ON(PTE_ENTRY_SIZE != sizeof(pte_t)); 548 BUILD_BUG_ON(PMD_ENTRY_SIZE != sizeof(pmd_t)); 549 BUILD_BUG_ON(PGD_ENTRY_SIZE != sizeof(pgd_t)); 550 BUILD_BUG_ON(PAGE_SHIFT + BITS_PER_PTE + BITS_PER_PMD + BITS_PER_PGD 551 > BITS_PER_LONG); 552 #if CONFIG_PGTABLE_LEVELS == 3 553 BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PMD); 554 #else 555 BUILD_BUG_ON(PT_INITIAL > PTRS_PER_PGD); 556 #endif 557 558 high_memory = __va((max_pfn << PAGE_SHIFT)); 559 set_max_mapnr(max_low_pfn); 560 memblock_free_all(); 561 562 #ifdef CONFIG_PA11 563 if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) { 564 pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START); 565 parisc_vmalloc_start = SET_MAP_OFFSET(pcxl_dma_start 566 + PCXL_DMA_MAP_SIZE); 567 } else 568 #endif 569 parisc_vmalloc_start = SET_MAP_OFFSET(MAP_START); 570 571 #if 0 572 /* 573 * Do not expose the virtual kernel memory layout to userspace. 574 * But keep code for debugging purposes. 575 */ 576 printk("virtual kernel memory layout:\n" 577 " vmalloc : 0x%px - 0x%px (%4ld MB)\n" 578 " fixmap : 0x%px - 0x%px (%4ld kB)\n" 579 " memory : 0x%px - 0x%px (%4ld MB)\n" 580 " .init : 0x%px - 0x%px (%4ld kB)\n" 581 " .data : 0x%px - 0x%px (%4ld kB)\n" 582 " .text : 0x%px - 0x%px (%4ld kB)\n", 583 584 (void*)VMALLOC_START, (void*)VMALLOC_END, 585 (VMALLOC_END - VMALLOC_START) >> 20, 586 587 (void *)FIXMAP_START, (void *)(FIXMAP_START + FIXMAP_SIZE), 588 (unsigned long)(FIXMAP_SIZE / 1024), 589 590 __va(0), high_memory, 591 ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, 592 593 __init_begin, __init_end, 594 ((unsigned long)__init_end - (unsigned long)__init_begin) >> 10, 595 596 _etext, _edata, 597 ((unsigned long)_edata - (unsigned long)_etext) >> 10, 598 599 _text, _etext, 600 ((unsigned long)_etext - (unsigned long)_text) >> 10); 601 #endif 602 } 603 604 unsigned long *empty_zero_page __ro_after_init; 605 EXPORT_SYMBOL(empty_zero_page); 606 607 /* 608 * pagetable_init() sets up the page tables 609 * 610 * Note that gateway_init() places the Linux gateway page at page 0. 611 * Since gateway pages cannot be dereferenced this has the desirable 612 * side effect of trapping those pesky NULL-reference errors in the 613 * kernel. 614 */ 615 static void __init pagetable_init(void) 616 { 617 int range; 618 619 /* Map each physical memory range to its kernel vaddr */ 620 621 for (range = 0; range < npmem_ranges; range++) { 622 unsigned long start_paddr; 623 unsigned long end_paddr; 624 unsigned long size; 625 626 start_paddr = pmem_ranges[range].start_pfn << PAGE_SHIFT; 627 size = pmem_ranges[range].pages << PAGE_SHIFT; 628 end_paddr = start_paddr + size; 629 630 map_pages((unsigned long)__va(start_paddr), start_paddr, 631 size, PAGE_KERNEL, 0); 632 } 633 634 #ifdef CONFIG_BLK_DEV_INITRD 635 if (initrd_end && initrd_end > mem_limit) { 636 printk(KERN_INFO "initrd: mapping %08lx-%08lx\n", initrd_start, initrd_end); 637 map_pages(initrd_start, __pa(initrd_start), 638 initrd_end - initrd_start, PAGE_KERNEL, 0); 639 } 640 #endif 641 642 empty_zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 643 if (!empty_zero_page) 644 panic("zero page allocation failed.\n"); 645 646 } 647 648 static void __init gateway_init(void) 649 { 650 unsigned long linux_gateway_page_addr; 651 /* FIXME: This is 'const' in order to trick the compiler 652 into not treating it as DP-relative data. */ 653 extern void * const linux_gateway_page; 654 655 linux_gateway_page_addr = LINUX_GATEWAY_ADDR & PAGE_MASK; 656 657 /* 658 * Setup Linux Gateway page. 659 * 660 * The Linux gateway page will reside in kernel space (on virtual 661 * page 0), so it doesn't need to be aliased into user space. 662 */ 663 664 map_pages(linux_gateway_page_addr, __pa(&linux_gateway_page), 665 PAGE_SIZE, PAGE_GATEWAY, 1); 666 } 667 668 static void __init parisc_bootmem_free(void) 669 { 670 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0, }; 671 672 max_zone_pfn[0] = memblock_end_of_DRAM(); 673 674 free_area_init(max_zone_pfn); 675 } 676 677 void __init paging_init(void) 678 { 679 setup_bootmem(); 680 pagetable_init(); 681 gateway_init(); 682 flush_cache_all_local(); /* start with known state */ 683 flush_tlb_all_local(NULL); 684 685 sparse_init(); 686 parisc_bootmem_free(); 687 } 688 689 #ifdef CONFIG_PA20 690 691 /* 692 * Currently, all PA20 chips have 18 bit protection IDs, which is the 693 * limiting factor (space ids are 32 bits). 694 */ 695 696 #define NR_SPACE_IDS 262144 697 698 #else 699 700 /* 701 * Currently we have a one-to-one relationship between space IDs and 702 * protection IDs. Older parisc chips (PCXS, PCXT, PCXL, PCXL2) only 703 * support 15 bit protection IDs, so that is the limiting factor. 704 * PCXT' has 18 bit protection IDs, but only 16 bit spaceids, so it's 705 * probably not worth the effort for a special case here. 706 */ 707 708 #define NR_SPACE_IDS 32768 709 710 #endif /* !CONFIG_PA20 */ 711 712 #define RECYCLE_THRESHOLD (NR_SPACE_IDS / 2) 713 #define SID_ARRAY_SIZE (NR_SPACE_IDS / (8 * sizeof(long))) 714 715 static unsigned long space_id[SID_ARRAY_SIZE] = { 1 }; /* disallow space 0 */ 716 static unsigned long dirty_space_id[SID_ARRAY_SIZE]; 717 static unsigned long space_id_index; 718 static unsigned long free_space_ids = NR_SPACE_IDS - 1; 719 static unsigned long dirty_space_ids = 0; 720 721 static DEFINE_SPINLOCK(sid_lock); 722 723 unsigned long alloc_sid(void) 724 { 725 unsigned long index; 726 727 spin_lock(&sid_lock); 728 729 if (free_space_ids == 0) { 730 if (dirty_space_ids != 0) { 731 spin_unlock(&sid_lock); 732 flush_tlb_all(); /* flush_tlb_all() calls recycle_sids() */ 733 spin_lock(&sid_lock); 734 } 735 BUG_ON(free_space_ids == 0); 736 } 737 738 free_space_ids--; 739 740 index = find_next_zero_bit(space_id, NR_SPACE_IDS, space_id_index); 741 space_id[BIT_WORD(index)] |= BIT_MASK(index); 742 space_id_index = index; 743 744 spin_unlock(&sid_lock); 745 746 return index << SPACEID_SHIFT; 747 } 748 749 void free_sid(unsigned long spaceid) 750 { 751 unsigned long index = spaceid >> SPACEID_SHIFT; 752 unsigned long *dirty_space_offset, mask; 753 754 dirty_space_offset = &dirty_space_id[BIT_WORD(index)]; 755 mask = BIT_MASK(index); 756 757 spin_lock(&sid_lock); 758 759 BUG_ON(*dirty_space_offset & mask); /* attempt to free space id twice */ 760 761 *dirty_space_offset |= mask; 762 dirty_space_ids++; 763 764 spin_unlock(&sid_lock); 765 } 766 767 768 #ifdef CONFIG_SMP 769 static void get_dirty_sids(unsigned long *ndirtyptr,unsigned long *dirty_array) 770 { 771 int i; 772 773 /* NOTE: sid_lock must be held upon entry */ 774 775 *ndirtyptr = dirty_space_ids; 776 if (dirty_space_ids != 0) { 777 for (i = 0; i < SID_ARRAY_SIZE; i++) { 778 dirty_array[i] = dirty_space_id[i]; 779 dirty_space_id[i] = 0; 780 } 781 dirty_space_ids = 0; 782 } 783 784 return; 785 } 786 787 static void recycle_sids(unsigned long ndirty,unsigned long *dirty_array) 788 { 789 int i; 790 791 /* NOTE: sid_lock must be held upon entry */ 792 793 if (ndirty != 0) { 794 for (i = 0; i < SID_ARRAY_SIZE; i++) { 795 space_id[i] ^= dirty_array[i]; 796 } 797 798 free_space_ids += ndirty; 799 space_id_index = 0; 800 } 801 } 802 803 #else /* CONFIG_SMP */ 804 805 static void recycle_sids(void) 806 { 807 int i; 808 809 /* NOTE: sid_lock must be held upon entry */ 810 811 if (dirty_space_ids != 0) { 812 for (i = 0; i < SID_ARRAY_SIZE; i++) { 813 space_id[i] ^= dirty_space_id[i]; 814 dirty_space_id[i] = 0; 815 } 816 817 free_space_ids += dirty_space_ids; 818 dirty_space_ids = 0; 819 space_id_index = 0; 820 } 821 } 822 #endif 823 824 /* 825 * flush_tlb_all() calls recycle_sids(), since whenever the entire tlb is 826 * purged, we can safely reuse the space ids that were released but 827 * not flushed from the tlb. 828 */ 829 830 #ifdef CONFIG_SMP 831 832 static unsigned long recycle_ndirty; 833 static unsigned long recycle_dirty_array[SID_ARRAY_SIZE]; 834 static unsigned int recycle_inuse; 835 836 void flush_tlb_all(void) 837 { 838 int do_recycle; 839 840 do_recycle = 0; 841 spin_lock(&sid_lock); 842 __inc_irq_stat(irq_tlb_count); 843 if (dirty_space_ids > RECYCLE_THRESHOLD) { 844 BUG_ON(recycle_inuse); /* FIXME: Use a semaphore/wait queue here */ 845 get_dirty_sids(&recycle_ndirty,recycle_dirty_array); 846 recycle_inuse++; 847 do_recycle++; 848 } 849 spin_unlock(&sid_lock); 850 on_each_cpu(flush_tlb_all_local, NULL, 1); 851 if (do_recycle) { 852 spin_lock(&sid_lock); 853 recycle_sids(recycle_ndirty,recycle_dirty_array); 854 recycle_inuse = 0; 855 spin_unlock(&sid_lock); 856 } 857 } 858 #else 859 void flush_tlb_all(void) 860 { 861 spin_lock(&sid_lock); 862 __inc_irq_stat(irq_tlb_count); 863 flush_tlb_all_local(NULL); 864 recycle_sids(); 865 spin_unlock(&sid_lock); 866 } 867 #endif 868