2 * linux/arch/x86_64/mm/init.c
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
6 * Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
9 #include <linux/module.h>
10 #include <linux/signal.h>
11 #include <linux/sched.h>
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/types.h>
16 #include <linux/ptrace.h>
17 #include <linux/mman.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/init.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/proc_fs.h>
25 #include <linux/pci.h>
26 #include <linux/poison.h>
27 #include <linux/dma-mapping.h>
28 #include <linux/module.h>
29 #include <linux/memory_hotplug.h>
31 #include <asm/processor.h>
32 #include <asm/system.h>
33 #include <asm/uaccess.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
37 #include <asm/fixmap.h>
41 #include <asm/mmu_context.h>
42 #include <asm/proto.h>
44 #include <asm/sections.h>
50 struct dma_mapping_ops* dma_ops;
51 EXPORT_SYMBOL(dma_ops);
53 static unsigned long dma_reserve __initdata;
55 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
58 * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
59 * physical space so we can cache the place of the first one and move
60 * around without checking the pgd every time.
65 long i, total = 0, reserved = 0;
66 long shared = 0, cached = 0;
70 printk(KERN_INFO "Mem-info:\n");
72 printk(KERN_INFO "Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
74 for_each_online_pgdat(pgdat) {
75 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
76 page = pfn_to_page(pgdat->node_start_pfn + i);
78 if (PageReserved(page))
80 else if (PageSwapCache(page))
82 else if (page_count(page))
83 shared += page_count(page) - 1;
86 printk(KERN_INFO "%lu pages of RAM\n", total);
87 printk(KERN_INFO "%lu reserved pages\n",reserved);
88 printk(KERN_INFO "%lu pages shared\n",shared);
89 printk(KERN_INFO "%lu pages swap cached\n",cached);
94 static __init void *spp_getpage(void)
98 ptr = (void *) get_zeroed_page(GFP_ATOMIC);
100 ptr = alloc_bootmem_pages(PAGE_SIZE);
101 if (!ptr || ((unsigned long)ptr & ~PAGE_MASK))
102 panic("set_pte_phys: cannot allocate page data %s\n", after_bootmem?"after bootmem":"");
104 Dprintk("spp_getpage %p\n", ptr);
108 static __init void set_pte_phys(unsigned long vaddr,
109 unsigned long phys, pgprot_t prot)
116 Dprintk("set_pte_phys %lx to %lx\n", vaddr, phys);
118 pgd = pgd_offset_k(vaddr);
119 if (pgd_none(*pgd)) {
120 printk("PGD FIXMAP MISSING, it should be setup in head.S!\n");
123 pud = pud_offset(pgd, vaddr);
124 if (pud_none(*pud)) {
125 pmd = (pmd_t *) spp_getpage();
126 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
127 if (pmd != pmd_offset(pud, 0)) {
128 printk("PAGETABLE BUG #01! %p <-> %p\n", pmd, pmd_offset(pud,0));
132 pmd = pmd_offset(pud, vaddr);
133 if (pmd_none(*pmd)) {
134 pte = (pte_t *) spp_getpage();
135 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
136 if (pte != pte_offset_kernel(pmd, 0)) {
137 printk("PAGETABLE BUG #02!\n");
141 new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
143 pte = pte_offset_kernel(pmd, vaddr);
144 if (!pte_none(*pte) &&
145 pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
147 set_pte(pte, new_pte);
150 * It's enough to flush this one mapping.
151 * (PGE mappings get flushed as well)
153 __flush_tlb_one(vaddr);
156 /* NOTE: this is meant to be run only at boot */
158 __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
160 unsigned long address = __fix_to_virt(idx);
162 if (idx >= __end_of_fixed_addresses) {
163 printk("Invalid __set_fixmap\n");
166 set_pte_phys(address, phys, prot);
169 unsigned long __initdata table_start, table_end;
171 extern pmd_t temp_boot_pmds[];
173 static struct temp_map {
177 } temp_mappings[] __initdata = {
178 { &temp_boot_pmds[0], (void *)(40UL * 1024 * 1024) },
179 { &temp_boot_pmds[1], (void *)(42UL * 1024 * 1024) },
183 static __meminit void *alloc_low_page(int *index, unsigned long *phys)
187 unsigned long pfn = table_end++, paddr;
191 adr = (void *)get_zeroed_page(GFP_ATOMIC);
197 panic("alloc_low_page: ran out of memory");
198 for (i = 0; temp_mappings[i].allocated; i++) {
199 if (!temp_mappings[i].pmd)
200 panic("alloc_low_page: ran out of temp mappings");
202 ti = &temp_mappings[i];
203 paddr = (pfn << PAGE_SHIFT) & PMD_MASK;
204 set_pmd(ti->pmd, __pmd(paddr | _KERNPG_TABLE | _PAGE_PSE));
207 adr = ti->address + ((pfn << PAGE_SHIFT) & ~PMD_MASK);
208 memset(adr, 0, PAGE_SIZE);
210 *phys = pfn * PAGE_SIZE;
214 static __meminit void unmap_low_page(int i)
221 ti = &temp_mappings[i];
222 set_pmd(ti->pmd, __pmd(0));
226 /* Must run before zap_low_mappings */
227 __init void *early_ioremap(unsigned long addr, unsigned long size)
229 unsigned long map = round_down(addr, LARGE_PAGE_SIZE);
231 /* actually usually some more */
232 if (size >= LARGE_PAGE_SIZE) {
235 set_pmd(temp_mappings[0].pmd, __pmd(map | _KERNPG_TABLE | _PAGE_PSE));
236 map += LARGE_PAGE_SIZE;
237 set_pmd(temp_mappings[1].pmd, __pmd(map | _KERNPG_TABLE | _PAGE_PSE));
239 return temp_mappings[0].address + (addr & (LARGE_PAGE_SIZE-1));
242 /* To avoid virtual aliases later */
243 __init void early_iounmap(void *addr, unsigned long size)
245 if ((void *)round_down((unsigned long)addr, LARGE_PAGE_SIZE) != temp_mappings[0].address)
246 printk("early_iounmap: bad address %p\n", addr);
247 set_pmd(temp_mappings[0].pmd, __pmd(0));
248 set_pmd(temp_mappings[1].pmd, __pmd(0));
252 static void __meminit
253 phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
255 int i = pmd_index(address);
257 for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
259 pmd_t *pmd = pmd_page + pmd_index(address);
261 if (address >= end) {
263 for (; i < PTRS_PER_PMD; i++, pmd++)
264 set_pmd(pmd, __pmd(0));
271 entry = _PAGE_NX|_PAGE_PSE|_KERNPG_TABLE|_PAGE_GLOBAL|address;
272 entry &= __supported_pte_mask;
273 set_pmd(pmd, __pmd(entry));
277 static void __meminit
278 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
280 pmd_t *pmd = pmd_offset(pud,0);
281 spin_lock(&init_mm.page_table_lock);
282 phys_pmd_init(pmd, address, end);
283 spin_unlock(&init_mm.page_table_lock);
287 static void __meminit phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
289 int i = pud_index(addr);
292 for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE ) {
294 unsigned long pmd_phys;
295 pud_t *pud = pud_page + pud_index(addr);
301 if (!after_bootmem && !e820_any_mapped(addr,addr+PUD_SIZE,0)) {
302 set_pud(pud, __pud(0));
307 phys_pmd_update(pud, addr, end);
311 pmd = alloc_low_page(&map, &pmd_phys);
312 spin_lock(&init_mm.page_table_lock);
313 set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
314 phys_pmd_init(pmd, addr, end);
315 spin_unlock(&init_mm.page_table_lock);
321 static void __init find_early_table_space(unsigned long end)
323 unsigned long puds, pmds, tables, start;
325 puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
326 pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
327 tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
328 round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
330 /* RED-PEN putting page tables only on node 0 could
331 cause a hotspot and fill up ZONE_DMA. The page tables
332 need roughly 0.5KB per GB. */
334 table_start = find_e820_area(start, end, tables);
335 if (table_start == -1UL)
336 panic("Cannot find space for the kernel page tables");
338 table_start >>= PAGE_SHIFT;
339 table_end = table_start;
342 /* Setup the direct mapping of the physical memory at PAGE_OFFSET.
343 This runs before bootmem is initialized and gets pages directly from the
344 physical memory. To access them they are temporarily mapped. */
345 void __meminit init_memory_mapping(unsigned long start, unsigned long end)
349 Dprintk("init_memory_mapping\n");
352 * Find space for the kernel direct mapping tables.
353 * Later we should allocate these tables in the local node of the memory
354 * mapped. Unfortunately this is done currently before the nodes are
358 find_early_table_space(end);
360 start = (unsigned long)__va(start);
361 end = (unsigned long)__va(end);
363 for (; start < end; start = next) {
365 unsigned long pud_phys;
366 pgd_t *pgd = pgd_offset_k(start);
370 pud = pud_offset(pgd, start & PGDIR_MASK);
372 pud = alloc_low_page(&map, &pud_phys);
374 next = start + PGDIR_SIZE;
377 phys_pud_init(pud, __pa(start), __pa(next));
379 set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
384 asm volatile("movq %%cr4,%0" : "=r" (mmu_cr4_features));
388 void __cpuinit zap_low_mappings(int cpu)
391 pgd_t *pgd = pgd_offset_k(0UL);
395 * For AP's, zap the low identity mappings by changing the cr3
396 * to init_level4_pgt and doing local flush tlb all
398 asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt)));
404 void __init paging_init(void)
406 unsigned long max_zone_pfns[MAX_NR_ZONES];
407 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
408 max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
409 max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
410 max_zone_pfns[ZONE_NORMAL] = end_pfn;
412 memory_present(0, 0, end_pfn);
414 free_area_init_nodes(max_zone_pfns);
418 /* Unmap a kernel mapping if it exists. This is useful to avoid prefetches
419 from the CPU leading to inconsistent cache lines. address and size
420 must be aligned to 2MB boundaries.
421 Does nothing when the mapping doesn't exist. */
422 void __init clear_kernel_mapping(unsigned long address, unsigned long size)
424 unsigned long end = address + size;
426 BUG_ON(address & ~LARGE_PAGE_MASK);
427 BUG_ON(size & ~LARGE_PAGE_MASK);
429 for (; address < end; address += LARGE_PAGE_SIZE) {
430 pgd_t *pgd = pgd_offset_k(address);
435 pud = pud_offset(pgd, address);
438 pmd = pmd_offset(pud, address);
439 if (!pmd || pmd_none(*pmd))
441 if (0 == (pmd_val(*pmd) & _PAGE_PSE)) {
442 /* Could handle this, but it should not happen currently. */
444 "clear_kernel_mapping: mapping has been split. will leak memory\n");
447 set_pmd(pmd, __pmd(0));
452 static inline int page_is_ram (unsigned long pagenr)
456 for (i = 0; i < e820.nr_map; i++) {
457 unsigned long addr, end;
459 if (e820.map[i].type != E820_RAM) /* not usable memory */
462 * !!!FIXME!!! Some BIOSen report areas as RAM that
463 * are not. Notably the 640->1Mb area. We need a sanity
466 addr = (e820.map[i].addr+PAGE_SIZE-1) >> PAGE_SHIFT;
467 end = (e820.map[i].addr+e820.map[i].size) >> PAGE_SHIFT;
468 if ((pagenr >= addr) && (pagenr < end))
475 * Memory hotplug specific functions
477 void online_page(struct page *page)
479 ClearPageReserved(page);
480 init_page_count(page);
486 #ifdef CONFIG_MEMORY_HOTPLUG
488 * Memory is added always to NORMAL zone. This means you will never get
489 * additional DMA/DMA32 memory.
491 int arch_add_memory(int nid, u64 start, u64 size)
493 struct pglist_data *pgdat = NODE_DATA(nid);
494 struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
495 unsigned long start_pfn = start >> PAGE_SHIFT;
496 unsigned long nr_pages = size >> PAGE_SHIFT;
499 init_memory_mapping(start, (start + size -1));
501 ret = __add_pages(zone, start_pfn, nr_pages);
507 printk("%s: Problem encountered in __add_pages!\n", __func__);
510 EXPORT_SYMBOL_GPL(arch_add_memory);
512 int remove_memory(u64 start, u64 size)
516 EXPORT_SYMBOL_GPL(remove_memory);
518 #if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
519 int memory_add_physaddr_to_nid(u64 start)
523 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
526 #endif /* CONFIG_MEMORY_HOTPLUG */
528 #ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
530 * Memory Hotadd without sparsemem. The mem_maps have been allocated in advance,
531 * just online the pages.
533 int __add_pages(struct zone *z, unsigned long start_pfn, unsigned long nr_pages)
537 unsigned long total = 0, mem = 0;
538 for (pfn = start_pfn; pfn < start_pfn + nr_pages; pfn++) {
539 if (pfn_valid(pfn)) {
540 online_page(pfn_to_page(pfn));
547 z->spanned_pages += total;
548 z->present_pages += mem;
549 z->zone_pgdat->node_spanned_pages += total;
550 z->zone_pgdat->node_present_pages += mem;
557 * devmem_is_allowed() checks to see if /dev/mem access to a certain address is
558 * valid. The argument is a physical page number.
561 * On x86-64, access has to be given to the first megabyte of ram because that area
562 * contains bios code and data regions used by X and dosemu and similar apps.
563 * Access has to be given to non-kernel-ram areas as well, these contain the PCI
564 * mmio resources as well as potential bios/acpi data regions.
566 int devmem_is_allowed(unsigned long pagenr)
570 if (!page_is_ram(pagenr))
576 EXPORT_SYMBOL_GPL(page_is_ram);
578 static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules,
581 void __init mem_init(void)
583 long codesize, reservedpages, datasize, initsize;
587 /* clear the zero-page */
588 memset(empty_zero_page, 0, PAGE_SIZE);
592 /* this will put all low memory onto the freelists */
594 totalram_pages = numa_free_all_bootmem();
596 totalram_pages = free_all_bootmem();
598 reservedpages = end_pfn - totalram_pages -
599 absent_pages_in_range(0, end_pfn);
603 codesize = (unsigned long) &_etext - (unsigned long) &_text;
604 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
605 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
607 /* Register memory areas for /proc/kcore */
608 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
609 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
610 VMALLOC_END-VMALLOC_START);
611 kclist_add(&kcore_kernel, &_stext, _end - _stext);
612 kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
613 kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
614 VSYSCALL_END - VSYSCALL_START);
616 printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
617 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
618 end_pfn << (PAGE_SHIFT-10),
620 reservedpages << (PAGE_SHIFT-10),
626 * Sync boot_level4_pgt mappings with the init_level4_pgt
627 * except for the low identity mappings which are already zapped
628 * in init_level4_pgt. This sync-up is essential for AP's bringup
630 memcpy(boot_level4_pgt+1, init_level4_pgt+1, (PTRS_PER_PGD-1)*sizeof(pgd_t));
634 void free_init_pages(char *what, unsigned long begin, unsigned long end)
641 printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
642 for (addr = begin; addr < end; addr += PAGE_SIZE) {
643 ClearPageReserved(virt_to_page(addr));
644 init_page_count(virt_to_page(addr));
645 memset((void *)(addr & ~(PAGE_SIZE-1)),
646 POISON_FREE_INITMEM, PAGE_SIZE);
652 void free_initmem(void)
654 memset(__initdata_begin, POISON_FREE_INITDATA,
655 __initdata_end - __initdata_begin);
656 free_init_pages("unused kernel memory",
657 (unsigned long)(&__init_begin),
658 (unsigned long)(&__init_end));
661 #ifdef CONFIG_DEBUG_RODATA
663 void mark_rodata_ro(void)
665 unsigned long addr = (unsigned long)__start_rodata;
667 for (; addr < (unsigned long)__end_rodata; addr += PAGE_SIZE)
668 change_page_attr_addr(addr, 1, PAGE_KERNEL_RO);
670 printk ("Write protecting the kernel read-only data: %luk\n",
671 (__end_rodata - __start_rodata) >> 10);
674 * change_page_attr_addr() requires a global_flush_tlb() call after it.
675 * We do this after the printk so that if something went wrong in the
676 * change, the printk gets out at least to give a better debug hint
677 * of who is the culprit.
683 #ifdef CONFIG_BLK_DEV_INITRD
684 void free_initrd_mem(unsigned long start, unsigned long end)
686 free_init_pages("initrd memory", start, end);
690 void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
693 int nid = phys_to_nid(phys);
695 unsigned long pfn = phys >> PAGE_SHIFT;
696 if (pfn >= end_pfn) {
697 /* This can happen with kdump kernels when accessing firmware
699 if (pfn < end_pfn_map)
701 printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
706 /* Should check here against the e820 map to avoid double free */
708 reserve_bootmem_node(NODE_DATA(nid), phys, len);
710 reserve_bootmem(phys, len);
712 if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
713 dma_reserve += len / PAGE_SIZE;
714 set_dma_reserve(dma_reserve);
718 int kern_addr_valid(unsigned long addr)
720 unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
726 if (above != 0 && above != -1UL)
729 pgd = pgd_offset_k(addr);
733 pud = pud_offset(pgd, addr);
737 pmd = pmd_offset(pud, addr);
741 return pfn_valid(pmd_pfn(*pmd));
743 pte = pte_offset_kernel(pmd, addr);
746 return pfn_valid(pte_pfn(*pte));
750 #include <linux/sysctl.h>
752 extern int exception_trace, page_fault_trace;
754 static ctl_table debug_table2[] = {
755 { 99, "exception-trace", &exception_trace, sizeof(int), 0644, NULL,
760 static ctl_table debug_root_table2[] = {
761 { .ctl_name = CTL_DEBUG, .procname = "debug", .mode = 0555,
762 .child = debug_table2 },
766 static __init int x8664_sysctl_init(void)
768 register_sysctl_table(debug_root_table2, 1);
771 __initcall(x8664_sysctl_init);
774 /* A pseudo VMA to allow ptrace access for the vsyscall page. This only
775 covers the 64bit vsyscall page now. 32bit has a real VMA now and does
776 not need special handling anymore. */
778 static struct vm_area_struct gate_vma = {
779 .vm_start = VSYSCALL_START,
780 .vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES << PAGE_SHIFT),
781 .vm_page_prot = PAGE_READONLY_EXEC,
782 .vm_flags = VM_READ | VM_EXEC
785 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
787 #ifdef CONFIG_IA32_EMULATION
788 if (test_tsk_thread_flag(tsk, TIF_IA32))
794 int in_gate_area(struct task_struct *task, unsigned long addr)
796 struct vm_area_struct *vma = get_gate_vma(task);
799 return (addr >= vma->vm_start) && (addr < vma->vm_end);
802 /* Use this when you have no reliable task/vma, typically from interrupt
803 * context. It is less reliable than using the task's vma and may give
806 int in_gate_area_no_task(unsigned long addr)
808 return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);