| /* |
| * |
| * Copyright (C) 1995 Linus Torvalds |
| * |
| * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/signal.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/string.h> |
| #include <linux/types.h> |
| #include <linux/ptrace.h> |
| #include <linux/mman.h> |
| #include <linux/mm.h> |
| #include <linux/hugetlb.h> |
| #include <linux/swap.h> |
| #include <linux/smp.h> |
| #include <linux/init.h> |
| #include <linux/highmem.h> |
| #include <linux/pagemap.h> |
| #include <linux/pci.h> |
| #include <linux/pfn.h> |
| #include <linux/poison.h> |
| #include <linux/bootmem.h> |
| #include <linux/memblock.h> |
| #include <linux/proc_fs.h> |
| #include <linux/memory_hotplug.h> |
| #include <linux/initrd.h> |
| #include <linux/cpumask.h> |
| #include <linux/gfp.h> |
| |
| #include <asm/asm.h> |
| #include <asm/bios_ebda.h> |
| #include <asm/processor.h> |
| #include <asm/uaccess.h> |
| #include <asm/pgtable.h> |
| #include <asm/dma.h> |
| #include <asm/fixmap.h> |
| #include <asm/e820.h> |
| #include <asm/apic.h> |
| #include <asm/bugs.h> |
| #include <asm/tlb.h> |
| #include <asm/tlbflush.h> |
| #include <asm/olpc_ofw.h> |
| #include <asm/pgalloc.h> |
| #include <asm/sections.h> |
| #include <asm/paravirt.h> |
| #include <asm/setup.h> |
| #include <asm/cacheflush.h> |
| #include <asm/page_types.h> |
| #include <asm/init.h> |
| |
| #include "mm_internal.h" |
| |
| unsigned long highstart_pfn, highend_pfn; |
| |
| static noinline int do_test_wp_bit(void); |
| |
| bool __read_mostly __vmalloc_start_set = false; |
| |
| /* |
| * Creates a middle page table and puts a pointer to it in the |
| * given global directory entry. This only returns the gd entry |
| * in non-PAE compilation mode, since the middle layer is folded. |
| */ |
| static pmd_t * __init one_md_table_init(pgd_t *pgd) |
| { |
| pud_t *pud; |
| pmd_t *pmd_table; |
| |
| #ifdef CONFIG_X86_PAE |
| if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { |
| pmd_table = (pmd_t *)alloc_low_page(); |
| paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); |
| set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); |
| pud = pud_offset(pgd, 0); |
| BUG_ON(pmd_table != pmd_offset(pud, 0)); |
| |
| return pmd_table; |
| } |
| #endif |
| pud = pud_offset(pgd, 0); |
| pmd_table = pmd_offset(pud, 0); |
| |
| return pmd_table; |
| } |
| |
| /* |
| * Create a page table and place a pointer to it in a middle page |
| * directory entry: |
| */ |
| static pte_t * __init one_page_table_init(pmd_t *pmd) |
| { |
| if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { |
| pte_t *page_table = (pte_t *)alloc_low_page(); |
| |
| paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); |
| set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); |
| BUG_ON(page_table != pte_offset_kernel(pmd, 0)); |
| } |
| |
| return pte_offset_kernel(pmd, 0); |
| } |
| |
| pmd_t * __init populate_extra_pmd(unsigned long vaddr) |
| { |
| int pgd_idx = pgd_index(vaddr); |
| int pmd_idx = pmd_index(vaddr); |
| |
| return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; |
| } |
| |
| pte_t * __init populate_extra_pte(unsigned long vaddr) |
| { |
| int pte_idx = pte_index(vaddr); |
| pmd_t *pmd; |
| |
| pmd = populate_extra_pmd(vaddr); |
| return one_page_table_init(pmd) + pte_idx; |
| } |
| |
| static unsigned long __init |
| page_table_range_init_count(unsigned long start, unsigned long end) |
| { |
| unsigned long count = 0; |
| #ifdef CONFIG_HIGHMEM |
| int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; |
| int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; |
| int pgd_idx, pmd_idx; |
| unsigned long vaddr; |
| |
| if (pmd_idx_kmap_begin == pmd_idx_kmap_end) |
| return 0; |
| |
| vaddr = start; |
| pgd_idx = pgd_index(vaddr); |
| |
| for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) { |
| for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); |
| pmd_idx++) { |
| if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin && |
| (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) |
| count++; |
| vaddr += PMD_SIZE; |
| } |
| pmd_idx = 0; |
| } |
| #endif |
| return count; |
| } |
| |
| static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, |
| unsigned long vaddr, pte_t *lastpte, |
| void **adr) |
| { |
| #ifdef CONFIG_HIGHMEM |
| /* |
| * Something (early fixmap) may already have put a pte |
| * page here, which causes the page table allocation |
| * to become nonlinear. Attempt to fix it, and if it |
| * is still nonlinear then we have to bug. |
| */ |
| int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; |
| int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; |
| |
| if (pmd_idx_kmap_begin != pmd_idx_kmap_end |
| && (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin |
| && (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) { |
| pte_t *newpte; |
| int i; |
| |
| BUG_ON(after_bootmem); |
| newpte = *adr; |
| for (i = 0; i < PTRS_PER_PTE; i++) |
| set_pte(newpte + i, pte[i]); |
| *adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE); |
| |
| paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT); |
| set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); |
| BUG_ON(newpte != pte_offset_kernel(pmd, 0)); |
| __flush_tlb_all(); |
| |
| paravirt_release_pte(__pa(pte) >> PAGE_SHIFT); |
| pte = newpte; |
| } |
| BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) |
| && vaddr > fix_to_virt(FIX_KMAP_END) |
| && lastpte && lastpte + PTRS_PER_PTE != pte); |
| #endif |
| return pte; |
| } |
| |
| /* |
| * This function initializes a certain range of kernel virtual memory |
| * with new bootmem page tables, everywhere page tables are missing in |
| * the given range. |
| * |
| * NOTE: The pagetables are allocated contiguous on the physical space |
| * so we can cache the place of the first one and move around without |
| * checking the pgd every time. |
| */ |
| static void __init |
| page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) |
| { |
| int pgd_idx, pmd_idx; |
| unsigned long vaddr; |
| pgd_t *pgd; |
| pmd_t *pmd; |
| pte_t *pte = NULL; |
| unsigned long count = page_table_range_init_count(start, end); |
| void *adr = NULL; |
| |
| if (count) |
| adr = alloc_low_pages(count); |
| |
| vaddr = start; |
| pgd_idx = pgd_index(vaddr); |
| pmd_idx = pmd_index(vaddr); |
| pgd = pgd_base + pgd_idx; |
| |
| for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { |
| pmd = one_md_table_init(pgd); |
| pmd = pmd + pmd_index(vaddr); |
| for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); |
| pmd++, pmd_idx++) { |
| pte = page_table_kmap_check(one_page_table_init(pmd), |
| pmd, vaddr, pte, &adr); |
| |
| vaddr += PMD_SIZE; |
| } |
| pmd_idx = 0; |
| } |
| } |
| |
| static inline int is_kernel_text(unsigned long addr) |
| { |
| if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * This maps the physical memory to kernel virtual address space, a total |
| * of max_low_pfn pages, by creating page tables starting from address |
| * PAGE_OFFSET: |
| */ |
| unsigned long __init |
| kernel_physical_mapping_init(unsigned long start, |
| unsigned long end, |
| unsigned long page_size_mask) |
| { |
| int use_pse = page_size_mask == (1<<PG_LEVEL_2M); |
| unsigned long last_map_addr = end; |
| unsigned long start_pfn, end_pfn; |
| pgd_t *pgd_base = swapper_pg_dir; |
| int pgd_idx, pmd_idx, pte_ofs; |
| unsigned long pfn; |
| pgd_t *pgd; |
| pmd_t *pmd; |
| pte_t *pte; |
| unsigned pages_2m, pages_4k; |
| int mapping_iter; |
| |
| start_pfn = start >> PAGE_SHIFT; |
| end_pfn = end >> PAGE_SHIFT; |
| |
| /* |
| * First iteration will setup identity mapping using large/small pages |
| * based on use_pse, with other attributes same as set by |
| * the early code in head_32.S |
| * |
| * Second iteration will setup the appropriate attributes (NX, GLOBAL..) |
| * as desired for the kernel identity mapping. |
| * |
| * This two pass mechanism conforms to the TLB app note which says: |
| * |
| * "Software should not write to a paging-structure entry in a way |
| * that would change, for any linear address, both the page size |
| * and either the page frame or attributes." |
| */ |
| mapping_iter = 1; |
| |
| if (!cpu_has_pse) |
| use_pse = 0; |
| |
| repeat: |
| pages_2m = pages_4k = 0; |
| pfn = start_pfn; |
| pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); |
| pgd = pgd_base + pgd_idx; |
| for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { |
| pmd = one_md_table_init(pgd); |
| |
| if (pfn >= end_pfn) |
| continue; |
| #ifdef CONFIG_X86_PAE |
| pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); |
| pmd += pmd_idx; |
| #else |
| pmd_idx = 0; |
| #endif |
| for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; |
| pmd++, pmd_idx++) { |
| unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; |
| |
| /* |
| * Map with big pages if possible, otherwise |
| * create normal page tables: |
| */ |
| if (use_pse) { |
| unsigned int addr2; |
| pgprot_t prot = PAGE_KERNEL_LARGE; |
| /* |
| * first pass will use the same initial |
| * identity mapping attribute + _PAGE_PSE. |
| */ |
| pgprot_t init_prot = |
| __pgprot(PTE_IDENT_ATTR | |
| _PAGE_PSE); |
| |
| pfn &= PMD_MASK >> PAGE_SHIFT; |
| addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + |
| PAGE_OFFSET + PAGE_SIZE-1; |
| |
| if (is_kernel_text(addr) || |
| is_kernel_text(addr2)) |
| prot = PAGE_KERNEL_LARGE_EXEC; |
| |
| pages_2m++; |
| if (mapping_iter == 1) |
| set_pmd(pmd, pfn_pmd(pfn, init_prot)); |
| else |
| set_pmd(pmd, pfn_pmd(pfn, prot)); |
| |
| pfn += PTRS_PER_PTE; |
| continue; |
| } |
| pte = one_page_table_init(pmd); |
| |
| pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); |
| pte += pte_ofs; |
| for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; |
| pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { |
| pgprot_t prot = PAGE_KERNEL; |
| /* |
| * first pass will use the same initial |
| * identity mapping attribute. |
| */ |
| pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); |
| |
| if (is_kernel_text(addr)) |
| prot = PAGE_KERNEL_EXEC; |
| |
| pages_4k++; |
| if (mapping_iter == 1) { |
| set_pte(pte, pfn_pte(pfn, init_prot)); |
| last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE; |
| } else |
| set_pte(pte, pfn_pte(pfn, prot)); |
| } |
| } |
| } |
| if (mapping_iter == 1) { |
| /* |
| * update direct mapping page count only in the first |
| * iteration. |
| */ |
| update_page_count(PG_LEVEL_2M, pages_2m); |
| update_page_count(PG_LEVEL_4K, pages_4k); |
| |
| /* |
| * local global flush tlb, which will flush the previous |
| * mappings present in both small and large page TLB's. |
| */ |
| __flush_tlb_all(); |
| |
| /* |
| * Second iteration will set the actual desired PTE attributes. |
| */ |
| mapping_iter = 2; |
| goto repeat; |
| } |
| return last_map_addr; |
| } |
| |
| pte_t *kmap_pte; |
| pgprot_t kmap_prot; |
| |
| static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr) |
| { |
| return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), |
| vaddr), vaddr), vaddr); |
| } |
| |
| static void __init kmap_init(void) |
| { |
| unsigned long kmap_vstart; |
| |
| /* |
| * Cache the first kmap pte: |
| */ |
| kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); |
| kmap_pte = kmap_get_fixmap_pte(kmap_vstart); |
| |
| kmap_prot = PAGE_KERNEL; |
| } |
| |
| #ifdef CONFIG_HIGHMEM |
| static void __init permanent_kmaps_init(pgd_t *pgd_base) |
| { |
| unsigned long vaddr; |
| pgd_t *pgd; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| |
| vaddr = PKMAP_BASE; |
| page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); |
| |
| pgd = swapper_pg_dir + pgd_index(vaddr); |
| pud = pud_offset(pgd, vaddr); |
| pmd = pmd_offset(pud, vaddr); |
| pte = pte_offset_kernel(pmd, vaddr); |
| pkmap_page_table = pte; |
| } |
| |
| void __init add_highpages_with_active_regions(int nid, |
| unsigned long start_pfn, unsigned long end_pfn) |
| { |
| phys_addr_t start, end; |
| u64 i; |
| |
| for_each_free_mem_range(i, nid, &start, &end, NULL) { |
| unsigned long pfn = clamp_t(unsigned long, PFN_UP(start), |
| start_pfn, end_pfn); |
| unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end), |
| start_pfn, end_pfn); |
| for ( ; pfn < e_pfn; pfn++) |
| if (pfn_valid(pfn)) |
| free_highmem_page(pfn_to_page(pfn)); |
| } |
| } |
| #else |
| static inline void permanent_kmaps_init(pgd_t *pgd_base) |
| { |
| } |
| #endif /* CONFIG_HIGHMEM */ |
| |
| void __init native_pagetable_init(void) |
| { |
| unsigned long pfn, va; |
| pgd_t *pgd, *base = swapper_pg_dir; |
| pud_t *pud; |
| pmd_t *pmd; |
| pte_t *pte; |
| |
| /* |
| * Remove any mappings which extend past the end of physical |
| * memory from the boot time page table. |
| * In virtual address space, we should have at least two pages |
| * from VMALLOC_END to pkmap or fixmap according to VMALLOC_END |
| * definition. And max_low_pfn is set to VMALLOC_END physical |
| * address. If initial memory mapping is doing right job, we |
| * should have pte used near max_low_pfn or one pmd is not present. |
| */ |
| for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) { |
| va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); |
| pgd = base + pgd_index(va); |
| if (!pgd_present(*pgd)) |
| break; |
| |
| pud = pud_offset(pgd, va); |
| pmd = pmd_offset(pud, va); |
| if (!pmd_present(*pmd)) |
| break; |
| |
| /* should not be large page here */ |
| if (pmd_large(*pmd)) { |
| pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n", |
| pfn, pmd, __pa(pmd)); |
| BUG_ON(1); |
| } |
| |
| pte = pte_offset_kernel(pmd, va); |
| if (!pte_present(*pte)) |
| break; |
| |
| printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n", |
| pfn, pmd, __pa(pmd), pte, __pa(pte)); |
| pte_clear(NULL, va, pte); |
| } |
| paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); |
| paging_init(); |
| } |
| |
| /* |
| * Build a proper pagetable for the kernel mappings. Up until this |
| * point, we've been running on some set of pagetables constructed by |
| * the boot process. |
| * |
| * If we're booting on native hardware, this will be a pagetable |
| * constructed in arch/x86/kernel/head_32.S. The root of the |
| * pagetable will be swapper_pg_dir. |
| * |
| * If we're booting paravirtualized under a hypervisor, then there are |
| * more options: we may already be running PAE, and the pagetable may |
| * or may not be based in swapper_pg_dir. In any case, |
| * paravirt_pagetable_init() will set up swapper_pg_dir |
| * appropriately for the rest of the initialization to work. |
| * |
| * In general, pagetable_init() assumes that the pagetable may already |
| * be partially populated, and so it avoids stomping on any existing |
| * mappings. |
| */ |
| void __init early_ioremap_page_table_range_init(void) |
| { |
| pgd_t *pgd_base = swapper_pg_dir; |
| unsigned long vaddr, end; |
| |
| /* |
| * Fixed mappings, only the page table structure has to be |
| * created - mappings will be set by set_fixmap(): |
| */ |
| vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; |
| end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; |
| page_table_range_init(vaddr, end, pgd_base); |
| early_ioremap_reset(); |
| } |
| |
| static void __init pagetable_init(void) |
| { |
| pgd_t *pgd_base = swapper_pg_dir; |
| |
| permanent_kmaps_init(pgd_base); |
| } |
| |
| pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP); |
| EXPORT_SYMBOL_GPL(__supported_pte_mask); |
| |
| /* user-defined highmem size */ |
| static unsigned int highmem_pages = -1; |
| |
| /* |
| * highmem=size forces highmem to be exactly 'size' bytes. |
| * This works even on boxes that have no highmem otherwise. |
| * This also works to reduce highmem size on bigger boxes. |
| */ |
| static int __init parse_highmem(char *arg) |
| { |
| if (!arg) |
| return -EINVAL; |
| |
| highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; |
| return 0; |
| } |
| early_param("highmem", parse_highmem); |
| |
| #define MSG_HIGHMEM_TOO_BIG \ |
| "highmem size (%luMB) is bigger than pages available (%luMB)!\n" |
| |
| #define MSG_LOWMEM_TOO_SMALL \ |
| "highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" |
| /* |
| * All of RAM fits into lowmem - but if user wants highmem |
| * artificially via the highmem=x boot parameter then create |
| * it: |
| */ |
| static void __init lowmem_pfn_init(void) |
| { |
| /* max_low_pfn is 0, we already have early_res support */ |
| max_low_pfn = max_pfn; |
| |
| if (highmem_pages == -1) |
| highmem_pages = 0; |
| #ifdef CONFIG_HIGHMEM |
| if (highmem_pages >= max_pfn) { |
| printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, |
| pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); |
| highmem_pages = 0; |
| } |
| if (highmem_pages) { |
| if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { |
| printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, |
| pages_to_mb(highmem_pages)); |
| highmem_pages = 0; |
| } |
| max_low_pfn -= highmem_pages; |
| } |
| #else |
| if (highmem_pages) |
| printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); |
| #endif |
| } |
| |
| #define MSG_HIGHMEM_TOO_SMALL \ |
| "only %luMB highmem pages available, ignoring highmem size of %luMB!\n" |
| |
| #define MSG_HIGHMEM_TRIMMED \ |
| "Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" |
| /* |
| * We have more RAM than fits into lowmem - we try to put it into |
| * highmem, also taking the highmem=x boot parameter into account: |
| */ |
| static void __init highmem_pfn_init(void) |
| { |
| max_low_pfn = MAXMEM_PFN; |
| |
| if (highmem_pages == -1) |
| highmem_pages = max_pfn - MAXMEM_PFN; |
| |
| if (highmem_pages + MAXMEM_PFN < max_pfn) |
| max_pfn = MAXMEM_PFN + highmem_pages; |
| |
| if (highmem_pages + MAXMEM_PFN > max_pfn) { |
| printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, |
| pages_to_mb(max_pfn - MAXMEM_PFN), |
| pages_to_mb(highmem_pages)); |
| highmem_pages = 0; |
| } |
| #ifndef CONFIG_HIGHMEM |
| /* Maximum memory usable is what is directly addressable */ |
| printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); |
| if (max_pfn > MAX_NONPAE_PFN) |
| printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); |
| else |
| printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); |
| max_pfn = MAXMEM_PFN; |
| #else /* !CONFIG_HIGHMEM */ |
| #ifndef CONFIG_HIGHMEM64G |
| if (max_pfn > MAX_NONPAE_PFN) { |
| max_pfn = MAX_NONPAE_PFN; |
| printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); |
| } |
| #endif /* !CONFIG_HIGHMEM64G */ |
| #endif /* !CONFIG_HIGHMEM */ |
| } |
| |
| /* |
| * Determine low and high memory ranges: |
| */ |
| void __init find_low_pfn_range(void) |
| { |
| /* it could update max_pfn */ |
| |
| if (max_pfn <= MAXMEM_PFN) |
| lowmem_pfn_init(); |
| else |
| highmem_pfn_init(); |
| } |
| |
| #ifndef CONFIG_NEED_MULTIPLE_NODES |
| void __init initmem_init(void) |
| { |
| #ifdef CONFIG_HIGHMEM |
| highstart_pfn = highend_pfn = max_pfn; |
| if (max_pfn > max_low_pfn) |
| highstart_pfn = max_low_pfn; |
| printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", |
| pages_to_mb(highend_pfn - highstart_pfn)); |
| num_physpages = highend_pfn; |
| high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; |
| #else |
| num_physpages = max_low_pfn; |
| high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; |
| #endif |
| |
| memblock_set_node(0, (phys_addr_t)ULLONG_MAX, 0); |
| sparse_memory_present_with_active_regions(0); |
| |
| #ifdef CONFIG_FLATMEM |
| max_mapnr = num_physpages; |
| #endif |
| __vmalloc_start_set = true; |
| |
| printk(KERN_NOTICE "%ldMB LOWMEM available.\n", |
| pages_to_mb(max_low_pfn)); |
| |
| setup_bootmem_allocator(); |
| } |
| #endif /* !CONFIG_NEED_MULTIPLE_NODES */ |
| |
| void __init setup_bootmem_allocator(void) |
| { |
| printk(KERN_INFO " mapped low ram: 0 - %08lx\n", |
| max_pfn_mapped<<PAGE_SHIFT); |
| printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); |
| } |
| |
| /* |
| * paging_init() sets up the page tables - note that the first 8MB are |
| * already mapped by head.S. |
| * |
| * This routines also unmaps the page at virtual kernel address 0, so |
| * that we can trap those pesky NULL-reference errors in the kernel. |
| */ |
| void __init paging_init(void) |
| { |
| pagetable_init(); |
| |
| __flush_tlb_all(); |
| |
| kmap_init(); |
| |
| /* |
| * NOTE: at this point the bootmem allocator is fully available. |
| */ |
| olpc_dt_build_devicetree(); |
| sparse_memory_present_with_active_regions(MAX_NUMNODES); |
| sparse_init(); |
| zone_sizes_init(); |
| } |
| |
| /* |
| * Test if the WP bit works in supervisor mode. It isn't supported on 386's |
| * and also on some strange 486's. All 586+'s are OK. This used to involve |
| * black magic jumps to work around some nasty CPU bugs, but fortunately the |
| * switch to using exceptions got rid of all that. |
| */ |
| static void __init test_wp_bit(void) |
| { |
| printk(KERN_INFO |
| "Checking if this processor honours the WP bit even in supervisor mode..."); |
| |
| /* Any page-aligned address will do, the test is non-destructive */ |
| __set_fixmap(FIX_WP_TEST, __pa(&swapper_pg_dir), PAGE_KERNEL_RO); |
| boot_cpu_data.wp_works_ok = do_test_wp_bit(); |
| clear_fixmap(FIX_WP_TEST); |
| |
| if (!boot_cpu_data.wp_works_ok) { |
| printk(KERN_CONT "No.\n"); |
| panic("Linux doesn't support CPUs with broken WP."); |
| } else { |
| printk(KERN_CONT "Ok.\n"); |
| } |
| } |
| |
| void __init mem_init(void) |
| { |
| int codesize, reservedpages, datasize, initsize; |
| int tmp; |
| |
| pci_iommu_alloc(); |
| |
| #ifdef CONFIG_FLATMEM |
| BUG_ON(!mem_map); |
| #endif |
| /* |
| * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to |
| * be done before free_all_bootmem(). Memblock use free low memory for |
| * temporary data (see find_range_array()) and for this purpose can use |
| * pages that was already passed to the buddy allocator, hence marked as |
| * not accessible in the page tables when compiled with |
| * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not |
| * important here. |
| */ |
| set_highmem_pages_init(); |
| |
| /* this will put all low memory onto the freelists */ |
| free_all_bootmem(); |
| |
| reservedpages = 0; |
| for (tmp = 0; tmp < max_low_pfn; tmp++) |
| /* |
| * Only count reserved RAM pages: |
| */ |
| if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) |
| reservedpages++; |
| |
| after_bootmem = 1; |
| |
| codesize = (unsigned long) &_etext - (unsigned long) &_text; |
| datasize = (unsigned long) &_edata - (unsigned long) &_etext; |
| initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; |
| |
| printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, " |
| "%dk reserved, %dk data, %dk init, %ldk highmem)\n", |
| nr_free_pages() << (PAGE_SHIFT-10), |
| num_physpages << (PAGE_SHIFT-10), |
| codesize >> 10, |
| reservedpages << (PAGE_SHIFT-10), |
| datasize >> 10, |
| initsize >> 10, |
| totalhigh_pages << (PAGE_SHIFT-10)); |
| |
| printk(KERN_INFO "virtual kernel memory layout:\n" |
| " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" |
| #ifdef CONFIG_HIGHMEM |
| " pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n" |
| #endif |
| " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n" |
| " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n" |
| " .init : 0x%08lx - 0x%08lx (%4ld kB)\n" |
| " .data : 0x%08lx - 0x%08lx (%4ld kB)\n" |
| " .text : 0x%08lx - 0x%08lx (%4ld kB)\n", |
| FIXADDR_START, FIXADDR_TOP, |
| (FIXADDR_TOP - FIXADDR_START) >> 10, |
| |
| #ifdef CONFIG_HIGHMEM |
| PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE, |
| (LAST_PKMAP*PAGE_SIZE) >> 10, |
| #endif |
| |
| VMALLOC_START, VMALLOC_END, |
| (VMALLOC_END - VMALLOC_START) >> 20, |
| |
| (unsigned long)__va(0), (unsigned long)high_memory, |
| ((unsigned long)high_memory - (unsigned long)__va(0)) >> 20, |
| |
| (unsigned long)&__init_begin, (unsigned long)&__init_end, |
| ((unsigned long)&__init_end - |
| (unsigned long)&__init_begin) >> 10, |
| |
| (unsigned long)&_etext, (unsigned long)&_edata, |
| ((unsigned long)&_edata - (unsigned long)&_etext) >> 10, |
| |
| (unsigned long)&_text, (unsigned long)&_etext, |
| ((unsigned long)&_etext - (unsigned long)&_text) >> 10); |
| |
| /* |
| * Check boundaries twice: Some fundamental inconsistencies can |
| * be detected at build time already. |
| */ |
| #define __FIXADDR_TOP (-PAGE_SIZE) |
| #ifdef CONFIG_HIGHMEM |
| BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); |
| BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); |
| #endif |
| #define high_memory (-128UL << 20) |
| BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); |
| #undef high_memory |
| #undef __FIXADDR_TOP |
| |
| #ifdef CONFIG_HIGHMEM |
| BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); |
| BUG_ON(VMALLOC_END > PKMAP_BASE); |
| #endif |
| BUG_ON(VMALLOC_START >= VMALLOC_END); |
| BUG_ON((unsigned long)high_memory > VMALLOC_START); |
| |
| if (boot_cpu_data.wp_works_ok < 0) |
| test_wp_bit(); |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG |
| int arch_add_memory(int nid, u64 start, u64 size) |
| { |
| struct pglist_data *pgdata = NODE_DATA(nid); |
| struct zone *zone = pgdata->node_zones + ZONE_HIGHMEM; |
| unsigned long start_pfn = start >> PAGE_SHIFT; |
| unsigned long nr_pages = size >> PAGE_SHIFT; |
| |
| return __add_pages(nid, zone, start_pfn, nr_pages); |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| int arch_remove_memory(u64 start, u64 size) |
| { |
| unsigned long start_pfn = start >> PAGE_SHIFT; |
| unsigned long nr_pages = size >> PAGE_SHIFT; |
| struct zone *zone; |
| |
| zone = page_zone(pfn_to_page(start_pfn)); |
| return __remove_pages(zone, start_pfn, nr_pages); |
| } |
| #endif |
| #endif |
| |
| /* |
| * This function cannot be __init, since exceptions don't work in that |
| * section. Put this after the callers, so that it cannot be inlined. |
| */ |
| static noinline int do_test_wp_bit(void) |
| { |
| char tmp_reg; |
| int flag; |
| |
| __asm__ __volatile__( |
| " movb %0, %1 \n" |
| "1: movb %1, %0 \n" |
| " xorl %2, %2 \n" |
| "2: \n" |
| _ASM_EXTABLE(1b,2b) |
| :"=m" (*(char *)fix_to_virt(FIX_WP_TEST)), |
| "=q" (tmp_reg), |
| "=r" (flag) |
| :"2" (1) |
| :"memory"); |
| |
| return flag; |
| } |
| |
| #ifdef CONFIG_DEBUG_RODATA |
| const int rodata_test_data = 0xC3; |
| EXPORT_SYMBOL_GPL(rodata_test_data); |
| |
| int kernel_set_to_readonly __read_mostly; |
| |
| void set_kernel_text_rw(void) |
| { |
| unsigned long start = PFN_ALIGN(_text); |
| unsigned long size = PFN_ALIGN(_etext) - start; |
| |
| if (!kernel_set_to_readonly) |
| return; |
| |
| pr_debug("Set kernel text: %lx - %lx for read write\n", |
| start, start+size); |
| |
| set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); |
| } |
| |
| void set_kernel_text_ro(void) |
| { |
| unsigned long start = PFN_ALIGN(_text); |
| unsigned long size = PFN_ALIGN(_etext) - start; |
| |
| if (!kernel_set_to_readonly) |
| return; |
| |
| pr_debug("Set kernel text: %lx - %lx for read only\n", |
| start, start+size); |
| |
| set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
| } |
| |
| static void mark_nxdata_nx(void) |
| { |
| /* |
| * When this called, init has already been executed and released, |
| * so everything past _etext should be NX. |
| */ |
| unsigned long start = PFN_ALIGN(_etext); |
| /* |
| * This comes from is_kernel_text upper limit. Also HPAGE where used: |
| */ |
| unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start; |
| |
| if (__supported_pte_mask & _PAGE_NX) |
| printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10); |
| set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT); |
| } |
| |
| void mark_rodata_ro(void) |
| { |
| unsigned long start = PFN_ALIGN(_text); |
| unsigned long size = PFN_ALIGN(_etext) - start; |
| |
| set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
| printk(KERN_INFO "Write protecting the kernel text: %luk\n", |
| size >> 10); |
| |
| kernel_set_to_readonly = 1; |
| |
| #ifdef CONFIG_CPA_DEBUG |
| printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", |
| start, start+size); |
| set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT); |
| |
| printk(KERN_INFO "Testing CPA: write protecting again\n"); |
| set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); |
| #endif |
| |
| start += size; |
| size = (unsigned long)__end_rodata - start; |
| set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
| printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", |
| size >> 10); |
| rodata_test(); |
| |
| #ifdef CONFIG_CPA_DEBUG |
| printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size); |
| set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); |
| |
| printk(KERN_INFO "Testing CPA: write protecting again\n"); |
| set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
| #endif |
| mark_nxdata_nx(); |
| } |
| #endif |
| |