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/bootmem.h>
9 #include <linux/highmem.h>
11 #include <linux/swap.h>
12 #include <asm/fixmap.h>
14 #include "as-layout.h"
17 #include "kern_util.h"
21 /* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
22 unsigned long *empty_zero_page = NULL;
23 /* allocated in paging_init and unchanged thereafter */
24 unsigned long *empty_bad_page = NULL;
25 pgd_t swapper_pg_dir[PTRS_PER_PGD];
26 unsigned long long highmem;
29 static unsigned long brk_end;
31 void unmap_physmem(void)
33 os_unmap_memory((void *) brk_end, uml_reserved - brk_end);
36 static void map_cb(void *unused)
38 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
42 static void setup_highmem(unsigned long highmem_start,
43 unsigned long highmem_len)
46 unsigned long highmem_pfn;
49 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
50 for (i = 0; i < highmem_len >> PAGE_SHIFT; i++) {
51 page = &mem_map[highmem_pfn + i];
52 ClearPageReserved(page);
53 init_page_count(page);
59 void __init mem_init(void)
61 /* clear the zero-page */
62 memset(empty_zero_page, 0, PAGE_SIZE);
64 /* Map in the area just after the brk now that kmalloc is about
67 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
69 initial_thread_cb(map_cb, NULL);
70 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
71 uml_reserved = brk_end;
73 /* this will put all low memory onto the freelists */
74 totalram_pages = free_all_bootmem();
75 max_low_pfn = totalram_pages;
77 totalhigh_pages = highmem >> PAGE_SHIFT;
78 totalram_pages += totalhigh_pages;
80 num_physpages = totalram_pages;
81 max_pfn = totalram_pages;
82 printk(KERN_INFO "Memory: %luk available\n",
83 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10));
87 setup_highmem(end_iomem, highmem);
92 * Create a page table and place a pointer to it in a middle page
95 static void __init one_page_table_init(pmd_t *pmd)
98 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
99 set_pmd(pmd, __pmd(_KERNPG_TABLE +
100 (unsigned long) __pa(pte)));
101 if (pte != pte_offset_kernel(pmd, 0))
106 static void __init one_md_table_init(pud_t *pud)
108 #ifdef CONFIG_3_LEVEL_PGTABLES
109 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
110 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
111 if (pmd_table != pmd_offset(pud, 0))
116 static void __init fixrange_init(unsigned long start, unsigned long end,
126 i = pgd_index(vaddr);
127 j = pmd_index(vaddr);
130 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
131 pud = pud_offset(pgd, vaddr);
133 one_md_table_init(pud);
134 pmd = pmd_offset(pud, vaddr);
135 for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
136 one_page_table_init(pmd);
143 #ifdef CONFIG_HIGHMEM
147 #define kmap_get_fixmap_pte(vaddr) \
148 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
151 static void __init kmap_init(void)
153 unsigned long kmap_vstart;
155 /* cache the first kmap pte */
156 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
157 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
159 kmap_prot = PAGE_KERNEL;
162 static void __init init_highmem(void)
174 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
176 pgd = swapper_pg_dir + pgd_index(vaddr);
177 pud = pud_offset(pgd, vaddr);
178 pmd = pmd_offset(pud, vaddr);
179 pte = pte_offset_kernel(pmd, vaddr);
180 pkmap_page_table = pte;
184 #endif /* CONFIG_HIGHMEM */
186 static void __init fixaddr_user_init( void)
188 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
189 long size = FIXADDR_USER_END - FIXADDR_USER_START;
194 unsigned long paddr, vaddr = FIXADDR_USER_START;
199 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
200 paddr = (unsigned long)alloc_bootmem_low_pages( size);
201 memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size);
203 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
204 paddr += PAGE_SIZE) {
205 pgd = swapper_pg_dir + pgd_index(vaddr);
206 pud = pud_offset(pgd, vaddr);
207 pmd = pmd_offset(pud, vaddr);
208 pte = pte_offset_kernel(pmd, vaddr);
209 pte_set_val( (*pte), paddr, PAGE_READONLY);
214 void __init paging_init(void)
216 unsigned long zones_size[MAX_NR_ZONES], vaddr;
219 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
220 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
221 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
224 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
225 (uml_physmem >> PAGE_SHIFT);
226 #ifdef CONFIG_HIGHMEM
227 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
229 free_area_init(zones_size);
232 * Fixed mappings, only the page table structure has to be
233 * created - mappings will be set by set_fixmap():
235 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
236 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
240 #ifdef CONFIG_HIGHMEM
245 struct page *arch_validate(struct page *page, gfp_t mask, int order)
247 unsigned long addr, zero = 0;
253 if (PageHighMem(page))
256 addr = (unsigned long) page_address(page);
257 for (i = 0; i < (1 << order); i++) {
258 current->thread.fault_addr = (void *) addr;
259 if (__do_copy_to_user((void __user *) addr, &zero,
261 ¤t->thread.fault_addr,
262 ¤t->thread.fault_catcher)) {
263 if (!(mask & __GFP_WAIT))
270 if (i == (1 << order))
272 page = alloc_pages(mask, order);
277 * This can't do anything because nothing in the kernel image can be freed
278 * since it's not in kernel physical memory.
281 void free_initmem(void)
285 #ifdef CONFIG_BLK_DEV_INITRD
286 void free_initrd_mem(unsigned long start, unsigned long end)
289 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
290 (end - start) >> 10);
291 for (; start < end; start += PAGE_SIZE) {
292 ClearPageReserved(virt_to_page(start));
293 init_page_count(virt_to_page(start));
302 int pfn, total = 0, reserved = 0;
303 int shared = 0, cached = 0;
307 printk(KERN_INFO "Mem-info:\n");
309 printk(KERN_INFO "Free swap: %6ldkB\n",
310 nr_swap_pages<<(PAGE_SHIFT-10));
313 page = pfn_to_page(pfn);
315 if (PageHighMem(page))
317 if (PageReserved(page))
319 else if (PageSwapCache(page))
321 else if (page_count(page))
322 shared += page_count(page) - 1;
324 printk(KERN_INFO "%d pages of RAM\n", total);
325 printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
326 printk(KERN_INFO "%d reserved pages\n", reserved);
327 printk(KERN_INFO "%d pages shared\n", shared);
328 printk(KERN_INFO "%d pages swap cached\n", cached);
331 /* Allocate and free page tables. */
333 pgd_t *pgd_alloc(struct mm_struct *mm)
335 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
338 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
339 memcpy(pgd + USER_PTRS_PER_PGD,
340 swapper_pg_dir + USER_PTRS_PER_PGD,
341 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
346 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
348 free_page((unsigned long) pgd);
351 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
355 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
359 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
363 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
367 #ifdef CONFIG_3_LEVEL_PGTABLES
368 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
370 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
373 memset(pmd, 0, PAGE_SIZE);