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1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/stddef.h>
7#include <linux/module.h>
8#include <linux/bootmem.h>
9#include <linux/highmem.h>
10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/slab.h>
13#include <asm/fixmap.h>
14#include <asm/page.h>
15#include "as-layout.h"
16#include "init.h"
17#include "kern.h"
18#include "kern_util.h"
19#include "mem_user.h"
20#include "os.h"
21
22/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
23unsigned long *empty_zero_page = NULL;
24EXPORT_SYMBOL(empty_zero_page);
25/* allocated in paging_init and unchanged thereafter */
26static unsigned long *empty_bad_page = NULL;
27
28/*
29 * Initialized during boot, and readonly for initializing page tables
30 * afterwards
31 */
32pgd_t swapper_pg_dir[PTRS_PER_PGD];
33
34/* Initialized at boot time, and readonly after that */
35unsigned long long highmem;
36int kmalloc_ok = 0;
37
38/* Used during early boot */
39static unsigned long brk_end;
40
41#ifdef CONFIG_HIGHMEM
42static void setup_highmem(unsigned long highmem_start,
43 unsigned long highmem_len)
44{
45 struct page *page;
46 unsigned long highmem_pfn;
47 int i;
48
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);
54 __free_page(page);
55 }
56}
57#endif
58
59void __init mem_init(void)
60{
61 /* clear the zero-page */
62 memset(empty_zero_page, 0, PAGE_SIZE);
63
64 /* Map in the area just after the brk now that kmalloc is about
65 * to be turned on.
66 */
67 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
68 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
69 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
70 uml_reserved = brk_end;
71
72 /* this will put all low memory onto the freelists */
73 totalram_pages = free_all_bootmem();
74 max_low_pfn = totalram_pages;
75#ifdef CONFIG_HIGHMEM
76 totalhigh_pages = highmem >> PAGE_SHIFT;
77 totalram_pages += totalhigh_pages;
78#endif
79 num_physpages = totalram_pages;
80 max_pfn = totalram_pages;
81 printk(KERN_INFO "Memory: %luk available\n",
82 nr_free_pages() << (PAGE_SHIFT-10));
83 kmalloc_ok = 1;
84
85#ifdef CONFIG_HIGHMEM
86 setup_highmem(end_iomem, highmem);
87#endif
88}
89
90/*
91 * Create a page table and place a pointer to it in a middle page
92 * directory entry.
93 */
94static void __init one_page_table_init(pmd_t *pmd)
95{
96 if (pmd_none(*pmd)) {
97 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
98 set_pmd(pmd, __pmd(_KERNPG_TABLE +
99 (unsigned long) __pa(pte)));
100 if (pte != pte_offset_kernel(pmd, 0))
101 BUG();
102 }
103}
104
105static void __init one_md_table_init(pud_t *pud)
106{
107#ifdef CONFIG_3_LEVEL_PGTABLES
108 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
109 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
110 if (pmd_table != pmd_offset(pud, 0))
111 BUG();
112#endif
113}
114
115static void __init fixrange_init(unsigned long start, unsigned long end,
116 pgd_t *pgd_base)
117{
118 pgd_t *pgd;
119 pud_t *pud;
120 pmd_t *pmd;
121 int i, j;
122 unsigned long vaddr;
123
124 vaddr = start;
125 i = pgd_index(vaddr);
126 j = pmd_index(vaddr);
127 pgd = pgd_base + i;
128
129 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
130 pud = pud_offset(pgd, vaddr);
131 if (pud_none(*pud))
132 one_md_table_init(pud);
133 pmd = pmd_offset(pud, vaddr);
134 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
135 one_page_table_init(pmd);
136 vaddr += PMD_SIZE;
137 }
138 j = 0;
139 }
140}
141
142#ifdef CONFIG_HIGHMEM
143pte_t *kmap_pte;
144pgprot_t kmap_prot;
145
146#define kmap_get_fixmap_pte(vaddr) \
147 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
148 (vaddr)), (vaddr))
149
150static void __init kmap_init(void)
151{
152 unsigned long kmap_vstart;
153
154 /* cache the first kmap pte */
155 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
156 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
157
158 kmap_prot = PAGE_KERNEL;
159}
160
161static void __init init_highmem(void)
162{
163 pgd_t *pgd;
164 pud_t *pud;
165 pmd_t *pmd;
166 pte_t *pte;
167 unsigned long vaddr;
168
169 /*
170 * Permanent kmaps:
171 */
172 vaddr = PKMAP_BASE;
173 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
174
175 pgd = swapper_pg_dir + pgd_index(vaddr);
176 pud = pud_offset(pgd, vaddr);
177 pmd = pmd_offset(pud, vaddr);
178 pte = pte_offset_kernel(pmd, vaddr);
179 pkmap_page_table = pte;
180
181 kmap_init();
182}
183#endif /* CONFIG_HIGHMEM */
184
185static void __init fixaddr_user_init( void)
186{
187#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
188 long size = FIXADDR_USER_END - FIXADDR_USER_START;
189 pgd_t *pgd;
190 pud_t *pud;
191 pmd_t *pmd;
192 pte_t *pte;
193 phys_t p;
194 unsigned long v, vaddr = FIXADDR_USER_START;
195
196 if (!size)
197 return;
198
199 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
200 v = (unsigned long) alloc_bootmem_low_pages(size);
201 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
202 p = __pa(v);
203 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
204 p += 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, p, PAGE_READONLY);
210 }
211#endif
212}
213
214void __init paging_init(void)
215{
216 unsigned long zones_size[MAX_NR_ZONES], vaddr;
217 int i;
218
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++)
222 zones_size[i] = 0;
223
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;
228#endif
229 free_area_init(zones_size);
230
231 /*
232 * Fixed mappings, only the page table structure has to be
233 * created - mappings will be set by set_fixmap():
234 */
235 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
236 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
237
238 fixaddr_user_init();
239
240#ifdef CONFIG_HIGHMEM
241 init_highmem();
242#endif
243}
244
245/*
246 * This can't do anything because nothing in the kernel image can be freed
247 * since it's not in kernel physical memory.
248 */
249
250void free_initmem(void)
251{
252}
253
254#ifdef CONFIG_BLK_DEV_INITRD
255void free_initrd_mem(unsigned long start, unsigned long end)
256{
257 if (start < end)
258 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
259 (end - start) >> 10);
260 for (; start < end; start += PAGE_SIZE) {
261 ClearPageReserved(virt_to_page(start));
262 init_page_count(virt_to_page(start));
263 free_page(start);
264 totalram_pages++;
265 }
266}
267#endif
268
269/* Allocate and free page tables. */
270
271pgd_t *pgd_alloc(struct mm_struct *mm)
272{
273 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
274
275 if (pgd) {
276 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
277 memcpy(pgd + USER_PTRS_PER_PGD,
278 swapper_pg_dir + USER_PTRS_PER_PGD,
279 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
280 }
281 return pgd;
282}
283
284void pgd_free(struct mm_struct *mm, pgd_t *pgd)
285{
286 free_page((unsigned long) pgd);
287}
288
289pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
290{
291 pte_t *pte;
292
293 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
294 return pte;
295}
296
297pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
298{
299 struct page *pte;
300
301 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
302 if (pte)
303 pgtable_page_ctor(pte);
304 return pte;
305}
306
307#ifdef CONFIG_3_LEVEL_PGTABLES
308pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
309{
310 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
311
312 if (pmd)
313 memset(pmd, 0, PAGE_SIZE);
314
315 return pmd;
316}
317#endif
318
319void *uml_kmalloc(int size, int flags)
320{
321 return kmalloc(size, flags);
322}