2 * Initialize MMU support.
4 * Copyright (C) 1998-2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
7 #include <linux/kernel.h>
8 #include <linux/init.h>
10 #include <linux/bootmem.h>
11 #include <linux/efi.h>
12 #include <linux/elf.h>
14 #include <linux/mmzone.h>
15 #include <linux/module.h>
16 #include <linux/personality.h>
17 #include <linux/reboot.h>
18 #include <linux/slab.h>
19 #include <linux/swap.h>
20 #include <linux/proc_fs.h>
21 #include <linux/bitops.h>
22 #include <linux/kexec.h>
24 #include <asm/a.out.h>
28 #include <asm/machvec.h>
30 #include <asm/patch.h>
31 #include <asm/pgalloc.h>
33 #include <asm/sections.h>
34 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/unistd.h>
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
42 extern void ia64_tlb_init (void);
44 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
46 #ifdef CONFIG_VIRTUAL_MEM_MAP
47 unsigned long vmalloc_end = VMALLOC_END_INIT;
48 EXPORT_SYMBOL(vmalloc_end);
49 struct page *vmem_map;
50 EXPORT_SYMBOL(vmem_map);
53 struct page *zero_page_memmap_ptr; /* map entry for zero page */
54 EXPORT_SYMBOL(zero_page_memmap_ptr);
57 __ia64_sync_icache_dcache (pte_t pte)
63 addr = (unsigned long) page_address(page);
65 if (test_bit(PG_arch_1, &page->flags))
66 return; /* i-cache is already coherent with d-cache */
68 flush_icache_range(addr, addr + (PAGE_SIZE << compound_order(page)));
69 set_bit(PG_arch_1, &page->flags); /* mark page as clean */
73 * Since DMA is i-cache coherent, any (complete) pages that were written via
74 * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
75 * flush them when they get mapped into an executable vm-area.
78 dma_mark_clean(void *addr, size_t size)
80 unsigned long pg_addr, end;
82 pg_addr = PAGE_ALIGN((unsigned long) addr);
83 end = (unsigned long) addr + size;
84 while (pg_addr + PAGE_SIZE <= end) {
85 struct page *page = virt_to_page(pg_addr);
86 set_bit(PG_arch_1, &page->flags);
92 ia64_set_rbs_bot (void)
94 unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
96 if (stack_size > MAX_USER_STACK_SIZE)
97 stack_size = MAX_USER_STACK_SIZE;
98 current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
102 * This performs some platform-dependent address space initialization.
103 * On IA-64, we want to setup the VM area for the register backing
104 * store (which grows upwards) and install the gateway page which is
105 * used for signal trampolines, etc.
108 ia64_init_addr_space (void)
110 struct vm_area_struct *vma;
115 * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
116 * the problem. When the process attempts to write to the register backing store
117 * for the first time, it will get a SEGFAULT in this case.
119 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
121 vma->vm_mm = current->mm;
122 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
123 vma->vm_end = vma->vm_start + PAGE_SIZE;
124 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
125 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
126 down_write(¤t->mm->mmap_sem);
127 if (insert_vm_struct(current->mm, vma)) {
128 up_write(¤t->mm->mmap_sem);
129 kmem_cache_free(vm_area_cachep, vma);
132 up_write(¤t->mm->mmap_sem);
135 /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
136 if (!(current->personality & MMAP_PAGE_ZERO)) {
137 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
139 vma->vm_mm = current->mm;
140 vma->vm_end = PAGE_SIZE;
141 vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
142 vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
143 down_write(¤t->mm->mmap_sem);
144 if (insert_vm_struct(current->mm, vma)) {
145 up_write(¤t->mm->mmap_sem);
146 kmem_cache_free(vm_area_cachep, vma);
149 up_write(¤t->mm->mmap_sem);
157 unsigned long addr, eaddr;
159 addr = (unsigned long) ia64_imva(__init_begin);
160 eaddr = (unsigned long) ia64_imva(__init_end);
161 while (addr < eaddr) {
162 ClearPageReserved(virt_to_page(addr));
163 init_page_count(virt_to_page(addr));
168 printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
169 (__init_end - __init_begin) >> 10);
173 free_initrd_mem (unsigned long start, unsigned long end)
177 * EFI uses 4KB pages while the kernel can use 4KB or bigger.
178 * Thus EFI and the kernel may have different page sizes. It is
179 * therefore possible to have the initrd share the same page as
180 * the end of the kernel (given current setup).
182 * To avoid freeing/using the wrong page (kernel sized) we:
183 * - align up the beginning of initrd
184 * - align down the end of initrd
187 * |=============| a000
193 * |=============| 8000
196 * |/////////////| 7000
199 * |=============| 6000
202 * K=kernel using 8KB pages
204 * In this example, we must free page 8000 ONLY. So we must align up
205 * initrd_start and keep initrd_end as is.
207 start = PAGE_ALIGN(start);
208 end = end & PAGE_MASK;
211 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
213 for (; start < end; start += PAGE_SIZE) {
214 if (!virt_addr_valid(start))
216 page = virt_to_page(start);
217 ClearPageReserved(page);
218 init_page_count(page);
225 * This installs a clean page in the kernel's page table.
227 static struct page * __init
228 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
235 if (!PageReserved(page))
236 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
239 pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */
242 pud = pud_alloc(&init_mm, pgd, address);
245 pmd = pmd_alloc(&init_mm, pud, address);
248 pte = pte_alloc_kernel(pmd, address);
253 set_pte(pte, mk_pte(page, pgprot));
256 /* no need for flush_tlb */
266 * Map the gate page twice: once read-only to export the ELF
267 * headers etc. and once execute-only page to enable
268 * privilege-promotion via "epc":
270 page = virt_to_page(ia64_imva(__start_gate_section));
271 put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
272 #ifdef HAVE_BUGGY_SEGREL
273 page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
274 put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
276 put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
277 /* Fill in the holes (if any) with read-only zero pages: */
281 for (addr = GATE_ADDR + PAGE_SIZE;
282 addr < GATE_ADDR + PERCPU_PAGE_SIZE;
285 put_kernel_page(ZERO_PAGE(0), addr,
287 put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
296 ia64_mmu_init (void *my_cpu_data)
298 unsigned long pta, impl_va_bits;
299 extern void __devinit tlb_init (void);
301 #ifdef CONFIG_DISABLE_VHPT
302 # define VHPT_ENABLE_BIT 0
304 # define VHPT_ENABLE_BIT 1
308 * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
309 * address space. The IA-64 architecture guarantees that at least 50 bits of
310 * virtual address space are implemented but if we pick a large enough page size
311 * (e.g., 64KB), the mapped address space is big enough that it will overlap with
312 * VMLPT. I assume that once we run on machines big enough to warrant 64KB pages,
313 * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
314 * problem in practice. Alternatively, we could truncate the top of the mapped
315 * address space to not permit mappings that would overlap with the VMLPT.
319 # define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
321 * The virtual page table has to cover the entire implemented address space within
322 * a region even though not all of this space may be mappable. The reason for
323 * this is that the Access bit and Dirty bit fault handlers perform
324 * non-speculative accesses to the virtual page table, so the address range of the
325 * virtual page table itself needs to be covered by virtual page table.
327 # define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits)
328 # define POW2(n) (1ULL << (n))
330 impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
332 if (impl_va_bits < 51 || impl_va_bits > 61)
333 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
335 * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
336 * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
337 * the test makes sure that our mapped space doesn't overlap the
338 * unimplemented hole in the middle of the region.
340 if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
341 (mapped_space_bits > impl_va_bits - 1))
342 panic("Cannot build a big enough virtual-linear page table"
343 " to cover mapped address space.\n"
344 " Try using a smaller page size.\n");
347 /* place the VMLPT at the end of each page-table mapped region: */
348 pta = POW2(61) - POW2(vmlpt_bits);
351 * Set the (virtually mapped linear) page table address. Bit
352 * 8 selects between the short and long format, bits 2-7 the
353 * size of the table, and bit 0 whether the VHPT walker is
356 ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
360 #ifdef CONFIG_HUGETLB_PAGE
361 ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
366 #ifdef CONFIG_VIRTUAL_MEM_MAP
367 int vmemmap_find_next_valid_pfn(int node, int i)
369 unsigned long end_address, hole_next_pfn;
370 unsigned long stop_address;
371 pg_data_t *pgdat = NODE_DATA(node);
373 end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
374 end_address = PAGE_ALIGN(end_address);
376 stop_address = (unsigned long) &vmem_map[
377 pgdat->node_start_pfn + pgdat->node_spanned_pages];
385 pgd = pgd_offset_k(end_address);
386 if (pgd_none(*pgd)) {
387 end_address += PGDIR_SIZE;
391 pud = pud_offset(pgd, end_address);
392 if (pud_none(*pud)) {
393 end_address += PUD_SIZE;
397 pmd = pmd_offset(pud, end_address);
398 if (pmd_none(*pmd)) {
399 end_address += PMD_SIZE;
403 pte = pte_offset_kernel(pmd, end_address);
405 if (pte_none(*pte)) {
406 end_address += PAGE_SIZE;
408 if ((end_address < stop_address) &&
409 (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
413 /* Found next valid vmem_map page */
415 } while (end_address < stop_address);
417 end_address = min(end_address, stop_address);
418 end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
419 hole_next_pfn = end_address / sizeof(struct page);
420 return hole_next_pfn - pgdat->node_start_pfn;
424 create_mem_map_page_table (u64 start, u64 end, void *arg)
426 unsigned long address, start_page, end_page;
427 struct page *map_start, *map_end;
434 map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
435 map_end = vmem_map + (__pa(end) >> PAGE_SHIFT);
437 start_page = (unsigned long) map_start & PAGE_MASK;
438 end_page = PAGE_ALIGN((unsigned long) map_end);
439 node = paddr_to_nid(__pa(start));
441 for (address = start_page; address < end_page; address += PAGE_SIZE) {
442 pgd = pgd_offset_k(address);
444 pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
445 pud = pud_offset(pgd, address);
448 pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
449 pmd = pmd_offset(pud, address);
452 pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
453 pte = pte_offset_kernel(pmd, address);
456 set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
462 struct memmap_init_callback_data {
470 virtual_memmap_init (u64 start, u64 end, void *arg)
472 struct memmap_init_callback_data *args;
473 struct page *map_start, *map_end;
475 args = (struct memmap_init_callback_data *) arg;
476 map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
477 map_end = vmem_map + (__pa(end) >> PAGE_SHIFT);
479 if (map_start < args->start)
480 map_start = args->start;
481 if (map_end > args->end)
485 * We have to initialize "out of bounds" struct page elements that fit completely
486 * on the same pages that were allocated for the "in bounds" elements because they
487 * may be referenced later (and found to be "reserved").
489 map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
490 map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
491 / sizeof(struct page));
493 if (map_start < map_end)
494 memmap_init_zone((unsigned long)(map_end - map_start),
495 args->nid, args->zone, page_to_pfn(map_start),
501 memmap_init (unsigned long size, int nid, unsigned long zone,
502 unsigned long start_pfn)
505 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
508 struct memmap_init_callback_data args;
510 start = pfn_to_page(start_pfn);
512 args.end = start + size;
516 efi_memmap_walk(virtual_memmap_init, &args);
521 ia64_pfn_valid (unsigned long pfn)
524 struct page *pg = pfn_to_page(pfn);
526 return (__get_user(byte, (char __user *) pg) == 0)
527 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
528 || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
530 EXPORT_SYMBOL(ia64_pfn_valid);
533 find_largest_hole (u64 start, u64 end, void *arg)
537 static u64 last_end = PAGE_OFFSET;
539 /* NOTE: this algorithm assumes efi memmap table is ordered */
541 if (*max_gap < (start - last_end))
542 *max_gap = start - last_end;
547 #endif /* CONFIG_VIRTUAL_MEM_MAP */
550 register_active_ranges(u64 start, u64 len, int nid)
552 u64 end = start + len;
555 if (start > crashk_res.start && start < crashk_res.end)
556 start = crashk_res.end;
557 if (end > crashk_res.start && end < crashk_res.end)
558 end = crashk_res.start;
562 add_active_range(nid, __pa(start) >> PAGE_SHIFT,
563 __pa(end) >> PAGE_SHIFT);
568 count_reserved_pages (u64 start, u64 end, void *arg)
570 unsigned long num_reserved = 0;
571 unsigned long *count = arg;
573 for (; start < end; start += PAGE_SIZE)
574 if (PageReserved(virt_to_page(start)))
576 *count += num_reserved;
581 find_max_min_low_pfn (unsigned long start, unsigned long end, void *arg)
583 unsigned long pfn_start, pfn_end;
584 #ifdef CONFIG_FLATMEM
585 pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
586 pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
588 pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
589 pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
591 min_low_pfn = min(min_low_pfn, pfn_start);
592 max_low_pfn = max(max_low_pfn, pfn_end);
597 * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
598 * system call handler. When this option is in effect, all fsyscalls will end up bubbling
599 * down into the kernel and calling the normal (heavy-weight) syscall handler. This is
600 * useful for performance testing, but conceivably could also come in handy for debugging
604 static int nolwsys __initdata;
607 nolwsys_setup (char *s)
613 __setup("nolwsys", nolwsys_setup);
618 long reserved_pages, codesize, datasize, initsize;
621 static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel;
623 BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
624 BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
625 BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
629 * This needs to be called _after_ the command line has been parsed but _before_
630 * any drivers that may need the PCI DMA interface are initialized or bootmem has
636 #ifdef CONFIG_FLATMEM
639 max_mapnr = max_low_pfn;
642 high_memory = __va(max_low_pfn * PAGE_SIZE);
644 kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE);
645 kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START);
646 kclist_add(&kcore_kernel, _stext, _end - _stext);
648 for_each_online_pgdat(pgdat)
649 if (pgdat->bdata->node_bootmem_map)
650 totalram_pages += free_all_bootmem_node(pgdat);
653 efi_memmap_walk(count_reserved_pages, &reserved_pages);
655 codesize = (unsigned long) _etext - (unsigned long) _stext;
656 datasize = (unsigned long) _edata - (unsigned long) _etext;
657 initsize = (unsigned long) __init_end - (unsigned long) __init_begin;
659 printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
660 "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
661 num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
662 reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
666 * For fsyscall entrpoints with no light-weight handler, use the ordinary
667 * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
668 * code can tell them apart.
670 for (i = 0; i < NR_syscalls; ++i) {
671 extern unsigned long fsyscall_table[NR_syscalls];
672 extern unsigned long sys_call_table[NR_syscalls];
674 if (!fsyscall_table[i] || nolwsys)
675 fsyscall_table[i] = sys_call_table[i] | 1;
679 #ifdef CONFIG_IA32_SUPPORT
684 #ifdef CONFIG_MEMORY_HOTPLUG
685 int arch_add_memory(int nid, u64 start, u64 size)
689 unsigned long start_pfn = start >> PAGE_SHIFT;
690 unsigned long nr_pages = size >> PAGE_SHIFT;
693 pgdat = NODE_DATA(nid);
695 zone = pgdat->node_zones + ZONE_NORMAL;
696 ret = __add_pages(zone, start_pfn, nr_pages);
699 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
704 #ifdef CONFIG_MEMORY_HOTREMOVE
705 int remove_memory(u64 start, u64 size)
707 unsigned long start_pfn, end_pfn;
708 unsigned long timeout = 120 * HZ;
710 start_pfn = start >> PAGE_SHIFT;
711 end_pfn = start_pfn + (size >> PAGE_SHIFT);
712 ret = offline_pages(start_pfn, end_pfn, timeout);
715 /* we can free mem_map at this point */
719 EXPORT_SYMBOL_GPL(remove_memory);
720 #endif /* CONFIG_MEMORY_HOTREMOVE */
724 * Even when CONFIG_IA32_SUPPORT is not enabled it is
725 * useful to have the Linux/x86 domain registered to
726 * avoid an attempted module load when emulators call
727 * personality(PER_LINUX32). This saves several milliseconds
730 static struct exec_domain ia32_exec_domain;
733 per_linux32_init(void)
735 ia32_exec_domain.name = "Linux/x86";
736 ia32_exec_domain.handler = NULL;
737 ia32_exec_domain.pers_low = PER_LINUX32;
738 ia32_exec_domain.pers_high = PER_LINUX32;
739 ia32_exec_domain.signal_map = default_exec_domain.signal_map;
740 ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
741 register_exec_domain(&ia32_exec_domain);
746 __initcall(per_linux32_init);