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author | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
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committer | Srikant Patnaik | 2015-01-13 15:08:24 +0530 |
commit | 97327692361306d1e6259021bc425e32832fdb50 (patch) | |
tree | fe9088f3248ec61e24f404f21b9793cb644b7f01 /arch/um/kernel/mem.c | |
parent | 2d05a8f663478a44e088d122e0d62109bbc801d0 (diff) | |
parent | a3a8b90b61e21be3dde9101c4e86c881e0f06210 (diff) | |
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dirty fix to merging
Diffstat (limited to 'arch/um/kernel/mem.c')
-rw-r--r-- | arch/um/kernel/mem.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c new file mode 100644 index 00000000..ebb86b21 --- /dev/null +++ b/arch/um/kernel/mem.c @@ -0,0 +1,322 @@ +/* + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + * Licensed under the GPL + */ + +#include <linux/stddef.h> +#include <linux/module.h> +#include <linux/bootmem.h> +#include <linux/highmem.h> +#include <linux/mm.h> +#include <linux/swap.h> +#include <linux/slab.h> +#include <asm/fixmap.h> +#include <asm/page.h> +#include "as-layout.h" +#include "init.h" +#include "kern.h" +#include "kern_util.h" +#include "mem_user.h" +#include "os.h" + +/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */ +unsigned long *empty_zero_page = NULL; +EXPORT_SYMBOL(empty_zero_page); +/* allocated in paging_init and unchanged thereafter */ +static unsigned long *empty_bad_page = NULL; + +/* + * Initialized during boot, and readonly for initializing page tables + * afterwards + */ +pgd_t swapper_pg_dir[PTRS_PER_PGD]; + +/* Initialized at boot time, and readonly after that */ +unsigned long long highmem; +int kmalloc_ok = 0; + +/* Used during early boot */ +static unsigned long brk_end; + +#ifdef CONFIG_HIGHMEM +static void setup_highmem(unsigned long highmem_start, + unsigned long highmem_len) +{ + struct page *page; + unsigned long highmem_pfn; + int i; + + highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT; + for (i = 0; i < highmem_len >> PAGE_SHIFT; i++) { + page = &mem_map[highmem_pfn + i]; + ClearPageReserved(page); + init_page_count(page); + __free_page(page); + } +} +#endif + +void __init mem_init(void) +{ + /* clear the zero-page */ + memset(empty_zero_page, 0, PAGE_SIZE); + + /* Map in the area just after the brk now that kmalloc is about + * to be turned on. + */ + brk_end = (unsigned long) UML_ROUND_UP(sbrk(0)); + map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); + free_bootmem(__pa(brk_end), uml_reserved - brk_end); + uml_reserved = brk_end; + + /* this will put all low memory onto the freelists */ + totalram_pages = free_all_bootmem(); + max_low_pfn = totalram_pages; +#ifdef CONFIG_HIGHMEM + totalhigh_pages = highmem >> PAGE_SHIFT; + totalram_pages += totalhigh_pages; +#endif + num_physpages = totalram_pages; + max_pfn = totalram_pages; + printk(KERN_INFO "Memory: %luk available\n", + nr_free_pages() << (PAGE_SHIFT-10)); + kmalloc_ok = 1; + +#ifdef CONFIG_HIGHMEM + setup_highmem(end_iomem, highmem); +#endif +} + +/* + * Create a page table and place a pointer to it in a middle page + * directory entry. + */ +static void __init one_page_table_init(pmd_t *pmd) +{ + if (pmd_none(*pmd)) { + pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pmd(pmd, __pmd(_KERNPG_TABLE + + (unsigned long) __pa(pte))); + if (pte != pte_offset_kernel(pmd, 0)) + BUG(); + } +} + +static void __init one_md_table_init(pud_t *pud) +{ +#ifdef CONFIG_3_LEVEL_PGTABLES + pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table))); + if (pmd_table != pmd_offset(pud, 0)) + BUG(); +#endif +} + +static void __init fixrange_init(unsigned long start, unsigned long end, + pgd_t *pgd_base) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + int i, j; + unsigned long vaddr; + + vaddr = start; + i = pgd_index(vaddr); + j = pmd_index(vaddr); + pgd = pgd_base + i; + + for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) { + pud = pud_offset(pgd, vaddr); + if (pud_none(*pud)) + one_md_table_init(pud); + pmd = pmd_offset(pud, vaddr); + for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) { + one_page_table_init(pmd); + vaddr += PMD_SIZE; + } + j = 0; + } +} + +#ifdef CONFIG_HIGHMEM +pte_t *kmap_pte; +pgprot_t kmap_prot; + +#define kmap_get_fixmap_pte(vaddr) \ + 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; +} + +static void __init init_highmem(void) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + unsigned long vaddr; + + /* + * Permanent kmaps: + */ + vaddr = PKMAP_BASE; + fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir); + + 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; + + kmap_init(); +} +#endif /* CONFIG_HIGHMEM */ + +static void __init fixaddr_user_init( void) +{ +#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA + long size = FIXADDR_USER_END - FIXADDR_USER_START; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + phys_t p; + unsigned long v, vaddr = FIXADDR_USER_START; + + if (!size) + return; + + fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); + v = (unsigned long) alloc_bootmem_low_pages(size); + memcpy((void *) v , (void *) FIXADDR_USER_START, size); + p = __pa(v); + for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE, + p += PAGE_SIZE) { + pgd = swapper_pg_dir + pgd_index(vaddr); + pud = pud_offset(pgd, vaddr); + pmd = pmd_offset(pud, vaddr); + pte = pte_offset_kernel(pmd, vaddr); + pte_set_val(*pte, p, PAGE_READONLY); + } +#endif +} + +void __init paging_init(void) +{ + unsigned long zones_size[MAX_NR_ZONES], vaddr; + int i; + + empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); + empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE); + for (i = 0; i < ARRAY_SIZE(zones_size); i++) + zones_size[i] = 0; + + zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) - + (uml_physmem >> PAGE_SHIFT); +#ifdef CONFIG_HIGHMEM + zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT; +#endif + free_area_init(zones_size); + + /* + * 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; + fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir); + + fixaddr_user_init(); + +#ifdef CONFIG_HIGHMEM + init_highmem(); +#endif +} + +/* + * This can't do anything because nothing in the kernel image can be freed + * since it's not in kernel physical memory. + */ + +void free_initmem(void) +{ +} + +#ifdef CONFIG_BLK_DEV_INITRD +void free_initrd_mem(unsigned long start, unsigned long end) +{ + if (start < end) + printk(KERN_INFO "Freeing initrd memory: %ldk freed\n", + (end - start) >> 10); + for (; start < end; start += PAGE_SIZE) { + ClearPageReserved(virt_to_page(start)); + init_page_count(virt_to_page(start)); + free_page(start); + totalram_pages++; + } +} +#endif + +/* Allocate and free page tables. */ + +pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL); + + if (pgd) { + memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); + memcpy(pgd + USER_PTRS_PER_PGD, + swapper_pg_dir + USER_PTRS_PER_PGD, + (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); + } + return pgd; +} + +void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + free_page((unsigned long) pgd); +} + +pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) +{ + pte_t *pte; + + pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); + return pte; +} + +pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + struct page *pte; + + pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); + if (pte) + pgtable_page_ctor(pte); + return pte; +} + +#ifdef CONFIG_3_LEVEL_PGTABLES +pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) +{ + pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL); + + if (pmd) + memset(pmd, 0, PAGE_SIZE); + + return pmd; +} +#endif + +void *uml_kmalloc(int size, int flags) +{ + return kmalloc(size, flags); +} |