2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
6 #include <linux/stddef.h>
7 #include <linux/module.h>
8 #include <linux/bootmem.h>
9 #include <linux/highmem.h>
11 #include <linux/swap.h>
12 #include <linux/slab.h>
13 #include <asm/fixmap.h>
15 #include <as-layout.h>
18 #include <kern_util.h>
22 /* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
23 unsigned long *empty_zero_page = NULL;
24 EXPORT_SYMBOL(empty_zero_page);
25 /* allocated in paging_init and unchanged thereafter */
26 static unsigned long *empty_bad_page = NULL;
29 * Initialized during boot, and readonly for initializing page tables
32 pgd_t swapper_pg_dir[PTRS_PER_PGD];
34 /* Initialized at boot time, and readonly after that */
35 unsigned long long highmem;
38 /* Used during early boot */
39 static unsigned long brk_end;
42 static void setup_highmem(unsigned long highmem_start,
43 unsigned long highmem_len)
45 unsigned long highmem_pfn;
48 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
49 for (i = 0; i < highmem_len >> PAGE_SHIFT; i++)
50 free_highmem_page(&mem_map[highmem_pfn + i]);
54 void __init mem_init(void)
56 /* clear the zero-page */
57 memset(empty_zero_page, 0, PAGE_SIZE);
59 /* Map in the area just after the brk now that kmalloc is about
62 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
63 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
64 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
65 uml_reserved = brk_end;
67 /* this will put all low memory onto the freelists */
69 max_low_pfn = totalram_pages;
71 setup_highmem(end_iomem, highmem);
73 max_pfn = totalram_pages;
74 mem_init_print_info(NULL);
79 * Create a page table and place a pointer to it in a middle page
82 static void __init one_page_table_init(pmd_t *pmd)
85 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
86 set_pmd(pmd, __pmd(_KERNPG_TABLE +
87 (unsigned long) __pa(pte)));
88 if (pte != pte_offset_kernel(pmd, 0))
93 static void __init one_md_table_init(pud_t *pud)
95 #ifdef CONFIG_3_LEVEL_PGTABLES
96 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
97 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
98 if (pmd_table != pmd_offset(pud, 0))
103 static void __init fixrange_init(unsigned long start, unsigned long end,
113 i = pgd_index(vaddr);
114 j = pmd_index(vaddr);
117 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
118 pud = pud_offset(pgd, vaddr);
120 one_md_table_init(pud);
121 pmd = pmd_offset(pud, vaddr);
122 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
123 one_page_table_init(pmd);
130 #ifdef CONFIG_HIGHMEM
134 #define kmap_get_fixmap_pte(vaddr) \
135 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
138 static void __init kmap_init(void)
140 unsigned long kmap_vstart;
142 /* cache the first kmap pte */
143 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
144 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
146 kmap_prot = PAGE_KERNEL;
149 static void __init init_highmem(void)
161 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
163 pgd = swapper_pg_dir + pgd_index(vaddr);
164 pud = pud_offset(pgd, vaddr);
165 pmd = pmd_offset(pud, vaddr);
166 pte = pte_offset_kernel(pmd, vaddr);
167 pkmap_page_table = pte;
171 #endif /* CONFIG_HIGHMEM */
173 static void __init fixaddr_user_init( void)
175 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
176 long size = FIXADDR_USER_END - FIXADDR_USER_START;
182 unsigned long v, vaddr = FIXADDR_USER_START;
187 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
188 v = (unsigned long) alloc_bootmem_low_pages(size);
189 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
191 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
193 pgd = swapper_pg_dir + pgd_index(vaddr);
194 pud = pud_offset(pgd, vaddr);
195 pmd = pmd_offset(pud, vaddr);
196 pte = pte_offset_kernel(pmd, vaddr);
197 pte_set_val(*pte, p, PAGE_READONLY);
202 void __init paging_init(void)
204 unsigned long zones_size[MAX_NR_ZONES], vaddr;
207 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
208 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
209 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
212 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
213 (uml_physmem >> PAGE_SHIFT);
214 #ifdef CONFIG_HIGHMEM
215 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
217 free_area_init(zones_size);
220 * Fixed mappings, only the page table structure has to be
221 * created - mappings will be set by set_fixmap():
223 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
224 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
228 #ifdef CONFIG_HIGHMEM
234 * This can't do anything because nothing in the kernel image can be freed
235 * since it's not in kernel physical memory.
238 void free_initmem(void)
242 #ifdef CONFIG_BLK_DEV_INITRD
243 void free_initrd_mem(unsigned long start, unsigned long end)
245 free_reserved_area((void *)start, (void *)end, -1, "initrd");
249 /* Allocate and free page tables. */
251 pgd_t *pgd_alloc(struct mm_struct *mm)
253 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
256 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
257 memcpy(pgd + USER_PTRS_PER_PGD,
258 swapper_pg_dir + USER_PTRS_PER_PGD,
259 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
264 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
266 free_page((unsigned long) pgd);
269 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
273 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
277 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
281 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
283 pgtable_page_ctor(pte);
287 #ifdef CONFIG_3_LEVEL_PGTABLES
288 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
290 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
293 memset(pmd, 0, PAGE_SIZE);
299 void *uml_kmalloc(int size, int flags)
301 return kmalloc(size, flags);