11da177e4SLinus Torvalds /* 2009ec2a9SJeff Dike * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 31da177e4SLinus Torvalds * Licensed under the GPL 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds 6009ec2a9SJeff Dike #include <linux/stddef.h> 773395a00SAl Viro #include <linux/module.h> 82013288fSMike Rapoport #include <linux/memblock.h> 9009ec2a9SJeff Dike #include <linux/highmem.h> 10009ec2a9SJeff Dike #include <linux/mm.h> 11009ec2a9SJeff Dike #include <linux/swap.h> 125a0e3ad6STejun Heo #include <linux/slab.h> 13009ec2a9SJeff Dike #include <asm/fixmap.h> 14009ec2a9SJeff Dike #include <asm/page.h> 1537185b33SAl Viro #include <as-layout.h> 1637185b33SAl Viro #include <init.h> 1737185b33SAl Viro #include <kern.h> 1837185b33SAl Viro #include <kern_util.h> 1937185b33SAl Viro #include <mem_user.h> 2037185b33SAl Viro #include <os.h> 211da177e4SLinus Torvalds 226bf79482SJeff Dike /* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */ 231da177e4SLinus Torvalds unsigned long *empty_zero_page = NULL; 2473395a00SAl Viro EXPORT_SYMBOL(empty_zero_page); 2580e39311SJeff Dike 2680e39311SJeff Dike /* 2780e39311SJeff Dike * Initialized during boot, and readonly for initializing page tables 2880e39311SJeff Dike * afterwards 2980e39311SJeff Dike */ 301da177e4SLinus Torvalds pgd_t swapper_pg_dir[PTRS_PER_PGD]; 3180e39311SJeff Dike 3280e39311SJeff Dike /* Initialized at boot time, and readonly after that */ 339902abd7SJeff Dike unsigned long long highmem; 341da177e4SLinus Torvalds int kmalloc_ok = 0; 351da177e4SLinus Torvalds 3680e39311SJeff Dike /* Used during early boot */ 371da177e4SLinus Torvalds static unsigned long brk_end; 381da177e4SLinus Torvalds 3997a1fcbbSJeff Dike void __init mem_init(void) 401da177e4SLinus Torvalds { 411da177e4SLinus Torvalds /* clear the zero-page */ 42c0a9290eSWANG Cong memset(empty_zero_page, 0, PAGE_SIZE); 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds /* Map in the area just after the brk now that kmalloc is about 451da177e4SLinus Torvalds * to be turned on. 461da177e4SLinus Torvalds */ 471da177e4SLinus Torvalds brk_end = (unsigned long) UML_ROUND_UP(sbrk(0)); 48ab26a527SJeff Dike map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); 492013288fSMike Rapoport memblock_free(__pa(brk_end), uml_reserved - brk_end); 501da177e4SLinus Torvalds uml_reserved = brk_end; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds /* this will put all low memory onto the freelists */ 53c6ffc5caSMike Rapoport memblock_free_all(); 54ca79b0c2SArun KS max_low_pfn = totalram_pages(); 553d6357deSArun KS max_pfn = max_low_pfn; 56715ee356SJiang Liu mem_init_print_info(NULL); 571da177e4SLinus Torvalds kmalloc_ok = 1; 581da177e4SLinus Torvalds } 591da177e4SLinus Torvalds 6012f49643SJeff Dike /* 6112f49643SJeff Dike * Create a page table and place a pointer to it in a middle page 6212f49643SJeff Dike * directory entry. 6312f49643SJeff Dike */ 6412f49643SJeff Dike static void __init one_page_table_init(pmd_t *pmd) 6512f49643SJeff Dike { 6612f49643SJeff Dike if (pmd_none(*pmd)) { 67e8625dceSMike Rapoport pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, 68e8625dceSMike Rapoport PAGE_SIZE); 698a7f97b9SMike Rapoport if (!pte) 708a7f97b9SMike Rapoport panic("%s: Failed to allocate %lu bytes align=%lx\n", 718a7f97b9SMike Rapoport __func__, PAGE_SIZE, PAGE_SIZE); 728a7f97b9SMike Rapoport 7312f49643SJeff Dike set_pmd(pmd, __pmd(_KERNPG_TABLE + 7412f49643SJeff Dike (unsigned long) __pa(pte))); 7512f49643SJeff Dike if (pte != pte_offset_kernel(pmd, 0)) 7612f49643SJeff Dike BUG(); 7712f49643SJeff Dike } 7812f49643SJeff Dike } 7912f49643SJeff Dike 8012f49643SJeff Dike static void __init one_md_table_init(pud_t *pud) 8112f49643SJeff Dike { 8212f49643SJeff Dike #ifdef CONFIG_3_LEVEL_PGTABLES 83e8625dceSMike Rapoport pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE); 848a7f97b9SMike Rapoport if (!pmd_table) 858a7f97b9SMike Rapoport panic("%s: Failed to allocate %lu bytes align=%lx\n", 868a7f97b9SMike Rapoport __func__, PAGE_SIZE, PAGE_SIZE); 878a7f97b9SMike Rapoport 8812f49643SJeff Dike set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); 8912f49643SJeff Dike if (pmd_table != pmd_offset(pud, 0)) 9012f49643SJeff Dike BUG(); 9112f49643SJeff Dike #endif 9212f49643SJeff Dike } 9312f49643SJeff Dike 941da177e4SLinus Torvalds static void __init fixrange_init(unsigned long start, unsigned long end, 951da177e4SLinus Torvalds pgd_t *pgd_base) 961da177e4SLinus Torvalds { 971da177e4SLinus Torvalds pgd_t *pgd; 9812f49643SJeff Dike pud_t *pud; 991da177e4SLinus Torvalds pmd_t *pmd; 1001da177e4SLinus Torvalds int i, j; 1011da177e4SLinus Torvalds unsigned long vaddr; 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds vaddr = start; 1041da177e4SLinus Torvalds i = pgd_index(vaddr); 1051da177e4SLinus Torvalds j = pmd_index(vaddr); 1061da177e4SLinus Torvalds pgd = pgd_base + i; 1071da177e4SLinus Torvalds 1081da177e4SLinus Torvalds for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { 10912f49643SJeff Dike pud = pud_offset(pgd, vaddr); 11012f49643SJeff Dike if (pud_none(*pud)) 11112f49643SJeff Dike one_md_table_init(pud); 11212f49643SJeff Dike pmd = pmd_offset(pud, vaddr); 113655e4ed0SJeff Dike for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) { 11412f49643SJeff Dike one_page_table_init(pmd); 1151da177e4SLinus Torvalds vaddr += PMD_SIZE; 1161da177e4SLinus Torvalds } 1171da177e4SLinus Torvalds j = 0; 1181da177e4SLinus Torvalds } 1191da177e4SLinus Torvalds } 1201da177e4SLinus Torvalds 1211da177e4SLinus Torvalds static void __init fixaddr_user_init( void) 1221da177e4SLinus Torvalds { 1239a0b3869Sviro@ZenIV.linux.org.uk #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 1241da177e4SLinus Torvalds long size = FIXADDR_USER_END - FIXADDR_USER_START; 1251da177e4SLinus Torvalds pgd_t *pgd; 1261da177e4SLinus Torvalds pud_t *pud; 1271da177e4SLinus Torvalds pmd_t *pmd; 1281da177e4SLinus Torvalds pte_t *pte; 129655e4ed0SJeff Dike phys_t p; 130655e4ed0SJeff Dike unsigned long v, vaddr = FIXADDR_USER_START; 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds if (!size) 1331da177e4SLinus Torvalds return; 1341da177e4SLinus Torvalds 1351da177e4SLinus Torvalds fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); 136e8625dceSMike Rapoport v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE); 1378a7f97b9SMike Rapoport if (!v) 1388a7f97b9SMike Rapoport panic("%s: Failed to allocate %lu bytes align=%lx\n", 1398a7f97b9SMike Rapoport __func__, size, PAGE_SIZE); 1408a7f97b9SMike Rapoport 141655e4ed0SJeff Dike memcpy((void *) v , (void *) FIXADDR_USER_START, size); 142655e4ed0SJeff Dike p = __pa(v); 143009ec2a9SJeff Dike for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE, 144655e4ed0SJeff Dike p += PAGE_SIZE) { 1451da177e4SLinus Torvalds pgd = swapper_pg_dir + pgd_index(vaddr); 1461da177e4SLinus Torvalds pud = pud_offset(pgd, vaddr); 1471da177e4SLinus Torvalds pmd = pmd_offset(pud, vaddr); 1481da177e4SLinus Torvalds pte = pte_offset_kernel(pmd, vaddr); 149655e4ed0SJeff Dike pte_set_val(*pte, p, PAGE_READONLY); 1501da177e4SLinus Torvalds } 1511da177e4SLinus Torvalds #endif 1521da177e4SLinus Torvalds } 1531da177e4SLinus Torvalds 15436e45463SJeff Dike void __init paging_init(void) 1551da177e4SLinus Torvalds { 1561da177e4SLinus Torvalds unsigned long zones_size[MAX_NR_ZONES], vaddr; 1571da177e4SLinus Torvalds int i; 1581da177e4SLinus Torvalds 159e8625dceSMike Rapoport empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE, 160e8625dceSMike Rapoport PAGE_SIZE); 1618a7f97b9SMike Rapoport if (!empty_zero_page) 1628a7f97b9SMike Rapoport panic("%s: Failed to allocate %lu bytes align=%lx\n", 1638a7f97b9SMike Rapoport __func__, PAGE_SIZE, PAGE_SIZE); 1648a7f97b9SMike Rapoport 16591b165c0SJeff Dike for (i = 0; i < ARRAY_SIZE(zones_size); i++) 1661da177e4SLinus Torvalds zones_size[i] = 0; 16791b165c0SJeff Dike 1680715501bSJeff Dike zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) - 1690715501bSJeff Dike (uml_physmem >> PAGE_SHIFT); 1701da177e4SLinus Torvalds free_area_init(zones_size); 1711da177e4SLinus Torvalds 1721da177e4SLinus Torvalds /* 1731da177e4SLinus Torvalds * Fixed mappings, only the page table structure has to be 1741da177e4SLinus Torvalds * created - mappings will be set by set_fixmap(): 1751da177e4SLinus Torvalds */ 1761da177e4SLinus Torvalds vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; 1771da177e4SLinus Torvalds fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds fixaddr_user_init(); 1801da177e4SLinus Torvalds } 1811da177e4SLinus Torvalds 1828192ab42SJeff Dike /* 1838192ab42SJeff Dike * This can't do anything because nothing in the kernel image can be freed 1841da177e4SLinus Torvalds * since it's not in kernel physical memory. 1851da177e4SLinus Torvalds */ 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds void free_initmem(void) 1881da177e4SLinus Torvalds { 1891da177e4SLinus Torvalds } 1901da177e4SLinus Torvalds 1911da177e4SLinus Torvalds #ifdef CONFIG_BLK_DEV_INITRD 1921da177e4SLinus Torvalds void free_initrd_mem(unsigned long start, unsigned long end) 1931da177e4SLinus Torvalds { 194dbe67df4SJiang Liu free_reserved_area((void *)start, (void *)end, -1, "initrd"); 1951da177e4SLinus Torvalds } 1961da177e4SLinus Torvalds #endif 1971da177e4SLinus Torvalds 1988192ab42SJeff Dike /* Allocate and free page tables. */ 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds pgd_t *pgd_alloc(struct mm_struct *mm) 2011da177e4SLinus Torvalds { 2021da177e4SLinus Torvalds pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); 2031da177e4SLinus Torvalds 2041da177e4SLinus Torvalds if (pgd) { 2051da177e4SLinus Torvalds memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); 2061da177e4SLinus Torvalds memcpy(pgd + USER_PTRS_PER_PGD, 2071da177e4SLinus Torvalds swapper_pg_dir + USER_PTRS_PER_PGD, 2081da177e4SLinus Torvalds (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); 2091da177e4SLinus Torvalds } 2101da177e4SLinus Torvalds return pgd; 2111da177e4SLinus Torvalds } 2121da177e4SLinus Torvalds 2135e541973SBenjamin Herrenschmidt void pgd_free(struct mm_struct *mm, pgd_t *pgd) 2141da177e4SLinus Torvalds { 2151da177e4SLinus Torvalds free_page((unsigned long) pgd); 2161da177e4SLinus Torvalds } 2171da177e4SLinus Torvalds 2184cf58924SJoel Fernandes (Google) pte_t *pte_alloc_one_kernel(struct mm_struct *mm) 2191da177e4SLinus Torvalds { 2201da177e4SLinus Torvalds pte_t *pte; 2211da177e4SLinus Torvalds 22232d6bd90SMichal Hocko pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO); 2231da177e4SLinus Torvalds return pte; 2241da177e4SLinus Torvalds } 2251da177e4SLinus Torvalds 2264cf58924SJoel Fernandes (Google) pgtable_t pte_alloc_one(struct mm_struct *mm) 2271da177e4SLinus Torvalds { 2281da177e4SLinus Torvalds struct page *pte; 2291da177e4SLinus Torvalds 23032d6bd90SMichal Hocko pte = alloc_page(GFP_KERNEL|__GFP_ZERO); 231647f884eSKirill A. Shutemov if (!pte) 232647f884eSKirill A. Shutemov return NULL; 233647f884eSKirill A. Shutemov if (!pgtable_page_ctor(pte)) { 234647f884eSKirill A. Shutemov __free_page(pte); 235647f884eSKirill A. Shutemov return NULL; 236647f884eSKirill A. Shutemov } 2371da177e4SLinus Torvalds return pte; 2381da177e4SLinus Torvalds } 2398192ab42SJeff Dike 2408192ab42SJeff Dike #ifdef CONFIG_3_LEVEL_PGTABLES 2418192ab42SJeff Dike pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) 2428192ab42SJeff Dike { 2438192ab42SJeff Dike pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL); 2448192ab42SJeff Dike 2458192ab42SJeff Dike if (pmd) 2468192ab42SJeff Dike memset(pmd, 0, PAGE_SIZE); 2478192ab42SJeff Dike 2488192ab42SJeff Dike return pmd; 2498192ab42SJeff Dike } 2508192ab42SJeff Dike #endif 25143f5b308SJeff Dike 25243f5b308SJeff Dike void *uml_kmalloc(int size, int flags) 25343f5b308SJeff Dike { 25443f5b308SJeff Dike return kmalloc(size, flags); 25543f5b308SJeff Dike } 256