diff options
Diffstat (limited to 'arch/um/kernel/mem.c')
-rw-r--r-- | arch/um/kernel/mem.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c new file mode 100644 index 0000000..f156661 --- /dev/null +++ b/arch/um/kernel/mem.c @@ -0,0 +1,359 @@ +/* + * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com) + * Licensed under the GPL + */ + +#include "linux/stddef.h" +#include "linux/kernel.h" +#include "linux/mm.h" +#include "linux/bootmem.h" +#include "linux/swap.h" +#include "linux/highmem.h" +#include "linux/gfp.h" +#include "asm/page.h" +#include "asm/fixmap.h" +#include "asm/pgalloc.h" +#include "user_util.h" +#include "kern_util.h" +#include "kern.h" +#include "mem_user.h" +#include "uml_uaccess.h" +#include "os.h" + +extern char __binary_start; + +/* Changed during early boot */ +unsigned long *empty_zero_page = NULL; +unsigned long *empty_bad_page = NULL; +pgd_t swapper_pg_dir[PTRS_PER_PGD]; +unsigned long highmem; +int kmalloc_ok = 0; + +static unsigned long brk_end; + +void unmap_physmem(void) +{ + os_unmap_memory((void *) brk_end, uml_reserved - brk_end); +} + +static void map_cb(void *unused) +{ + map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0); +} + +#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); + set_bit(PG_highmem, &page->flags); + set_page_count(page, 1); + __free_page(page); + } +} +#endif + +void mem_init(void) +{ + unsigned long start; + + max_low_pfn = (high_physmem - uml_physmem) >> PAGE_SHIFT; + + /* clear the zero-page */ + memset((void *) 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_cb(NULL); + initial_thread_cb(map_cb, NULL); + free_bootmem(__pa(brk_end), uml_reserved - brk_end); + uml_reserved = brk_end; + + /* Fill in any hole at the start of the binary */ + start = (unsigned long) &__binary_start & PAGE_MASK; + if(uml_physmem != start){ + map_memory(uml_physmem, __pa(uml_physmem), start - uml_physmem, + 1, 1, 0); + } + + /* this will put all low memory onto the freelists */ + totalram_pages = free_all_bootmem(); + totalhigh_pages = highmem >> PAGE_SHIFT; + totalram_pages += totalhigh_pages; + num_physpages = totalram_pages; + max_pfn = totalram_pages; + printk(KERN_INFO "Memory: %luk available\n", + (unsigned long) nr_free_pages() << (PAGE_SHIFT-10)); + kmalloc_ok = 1; + +#ifdef CONFIG_HIGHMEM + setup_highmem(end_iomem, highmem); +#endif +} + +static void __init fixrange_init(unsigned long start, unsigned long end, + pgd_t *pgd_base) +{ + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + 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++) { + pmd = (pmd_t *)pgd; + for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) { + if (pmd_none(*pmd)) { + 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(); + } + 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_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) +{ +#if 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; + unsigned long paddr, vaddr = FIXADDR_USER_START; + + if ( ! size ) + return; + + fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir); + paddr = (unsigned long)alloc_bootmem_low_pages( size); + memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size); + paddr = __pa(paddr); + for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=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), paddr, PAGE_READONLY); + } +#endif +} + +void 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<sizeof(zones_size)/sizeof(zones_size[0]);i++) + zones_size[i] = 0; + zones_size[0] = (end_iomem >> PAGE_SHIFT) - (uml_physmem >> PAGE_SHIFT); + zones_size[2] = highmem >> PAGE_SHIFT; + 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 +} + +struct page *arch_validate(struct page *page, int mask, int order) +{ + unsigned long addr, zero = 0; + int i; + + again: + if(page == NULL) return(page); + if(PageHighMem(page)) return(page); + + addr = (unsigned long) page_address(page); + for(i = 0; i < (1 << order); i++){ + current->thread.fault_addr = (void *) addr; + if(__do_copy_to_user((void __user *) addr, &zero, + sizeof(zero), + ¤t->thread.fault_addr, + ¤t->thread.fault_catcher)){ + if(!(mask & __GFP_WAIT)) return(NULL); + else break; + } + addr += PAGE_SIZE; + } + + if(i == (1 << order)) return(page); + page = alloc_pages(mask, order); + goto again; +} + +/* 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 ("Freeing initrd memory: %ldk freed\n", + (end - start) >> 10); + for (; start < end; start += PAGE_SIZE) { + ClearPageReserved(virt_to_page(start)); + set_page_count(virt_to_page(start), 1); + free_page(start); + totalram_pages++; + } +} + +#endif + +void show_mem(void) +{ + int pfn, total = 0, reserved = 0; + int shared = 0, cached = 0; + int highmem = 0; + struct page *page; + + printk("Mem-info:\n"); + show_free_areas(); + printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10)); + pfn = max_mapnr; + while(pfn-- > 0) { + page = pfn_to_page(pfn); + total++; + if(PageHighMem(page)) + highmem++; + if(PageReserved(page)) + reserved++; + else if(PageSwapCache(page)) + cached++; + else if(page_count(page)) + shared += page_count(page) - 1; + } + printk("%d pages of RAM\n", total); + printk("%d pages of HIGHMEM\n", highmem); + printk("%d reserved pages\n", reserved); + printk("%d pages shared\n", shared); + printk("%d pages swap cached\n", cached); +} + +/* + * 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(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; +} + +struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) +{ + struct page *pte; + + pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); + return pte; +} + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |