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/bootmem.h>
8 #include <linux/gfp.h>
9 #include <linux/highmem.h>
10 #include <linux/mm.h>
11 #include <linux/swap.h>
12 #include <asm/fixmap.h>
13 #include <asm/page.h>
14 #include "as-layout.h"
15 #include "init.h"
16 #include "kern.h"
17 #include "kern_util.h"
18 #include "mem_user.h"
19 #include "os.h"
20
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 static unsigned long *empty_bad_page = NULL;
25
26 /*
27 * Initialized during boot, and readonly for initializing page tables
28 * afterwards
29 */
30 pgd_t swapper_pg_dir[PTRS_PER_PGD];
31
32 /* Initialized at boot time, and readonly after that */
33 unsigned long long highmem;
34 int kmalloc_ok = 0;
35
36 /* Used during early boot */
37 static unsigned long brk_end;
38
39 #ifdef CONFIG_HIGHMEM
setup_highmem(unsigned long highmem_start,unsigned long highmem_len)40 static void setup_highmem(unsigned long highmem_start,
41 unsigned long highmem_len)
42 {
43 struct page *page;
44 unsigned long highmem_pfn;
45 int i;
46
47 highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
48 for (i = 0; i < highmem_len >> PAGE_SHIFT; i++) {
49 page = &mem_map[highmem_pfn + i];
50 ClearPageReserved(page);
51 init_page_count(page);
52 __free_page(page);
53 }
54 }
55 #endif
56
mem_init(void)57 void __init mem_init(void)
58 {
59 /* clear the zero-page */
60 memset(empty_zero_page, 0, PAGE_SIZE);
61
62 /* Map in the area just after the brk now that kmalloc is about
63 * to be turned on.
64 */
65 brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
66 map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
67 free_bootmem(__pa(brk_end), uml_reserved - brk_end);
68 uml_reserved = brk_end;
69
70 /* this will put all low memory onto the freelists */
71 totalram_pages = free_all_bootmem();
72 max_low_pfn = totalram_pages;
73 #ifdef CONFIG_HIGHMEM
74 totalhigh_pages = highmem >> PAGE_SHIFT;
75 totalram_pages += totalhigh_pages;
76 #endif
77 num_physpages = totalram_pages;
78 max_pfn = totalram_pages;
79 printk(KERN_INFO "Memory: %luk available\n",
80 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10));
81 kmalloc_ok = 1;
82
83 #ifdef CONFIG_HIGHMEM
84 setup_highmem(end_iomem, highmem);
85 #endif
86 }
87
88 /*
89 * Create a page table and place a pointer to it in a middle page
90 * directory entry.
91 */
one_page_table_init(pmd_t * pmd)92 static void __init one_page_table_init(pmd_t *pmd)
93 {
94 if (pmd_none(*pmd)) {
95 pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
96 set_pmd(pmd, __pmd(_KERNPG_TABLE +
97 (unsigned long) __pa(pte)));
98 if (pte != pte_offset_kernel(pmd, 0))
99 BUG();
100 }
101 }
102
one_md_table_init(pud_t * pud)103 static void __init one_md_table_init(pud_t *pud)
104 {
105 #ifdef CONFIG_3_LEVEL_PGTABLES
106 pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
107 set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
108 if (pmd_table != pmd_offset(pud, 0))
109 BUG();
110 #endif
111 }
112
fixrange_init(unsigned long start,unsigned long end,pgd_t * pgd_base)113 static void __init fixrange_init(unsigned long start, unsigned long end,
114 pgd_t *pgd_base)
115 {
116 pgd_t *pgd;
117 pud_t *pud;
118 pmd_t *pmd;
119 int i, j;
120 unsigned long vaddr;
121
122 vaddr = start;
123 i = pgd_index(vaddr);
124 j = pmd_index(vaddr);
125 pgd = pgd_base + i;
126
127 for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
128 pud = pud_offset(pgd, vaddr);
129 if (pud_none(*pud))
130 one_md_table_init(pud);
131 pmd = pmd_offset(pud, vaddr);
132 for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
133 one_page_table_init(pmd);
134 vaddr += PMD_SIZE;
135 }
136 j = 0;
137 }
138 }
139
140 #ifdef CONFIG_HIGHMEM
141 pte_t *kmap_pte;
142 pgprot_t kmap_prot;
143
144 #define kmap_get_fixmap_pte(vaddr) \
145 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
146 (vaddr)), (vaddr))
147
kmap_init(void)148 static void __init kmap_init(void)
149 {
150 unsigned long kmap_vstart;
151
152 /* cache the first kmap pte */
153 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
154 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
155
156 kmap_prot = PAGE_KERNEL;
157 }
158
init_highmem(void)159 static void __init init_highmem(void)
160 {
161 pgd_t *pgd;
162 pud_t *pud;
163 pmd_t *pmd;
164 pte_t *pte;
165 unsigned long vaddr;
166
167 /*
168 * Permanent kmaps:
169 */
170 vaddr = PKMAP_BASE;
171 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
172
173 pgd = swapper_pg_dir + pgd_index(vaddr);
174 pud = pud_offset(pgd, vaddr);
175 pmd = pmd_offset(pud, vaddr);
176 pte = pte_offset_kernel(pmd, vaddr);
177 pkmap_page_table = pte;
178
179 kmap_init();
180 }
181 #endif /* CONFIG_HIGHMEM */
182
fixaddr_user_init(void)183 static void __init fixaddr_user_init( void)
184 {
185 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
186 long size = FIXADDR_USER_END - FIXADDR_USER_START;
187 pgd_t *pgd;
188 pud_t *pud;
189 pmd_t *pmd;
190 pte_t *pte;
191 phys_t p;
192 unsigned long v, vaddr = FIXADDR_USER_START;
193
194 if (!size)
195 return;
196
197 fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
198 v = (unsigned long) alloc_bootmem_low_pages(size);
199 memcpy((void *) v , (void *) FIXADDR_USER_START, size);
200 p = __pa(v);
201 for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
202 p += PAGE_SIZE) {
203 pgd = swapper_pg_dir + pgd_index(vaddr);
204 pud = pud_offset(pgd, vaddr);
205 pmd = pmd_offset(pud, vaddr);
206 pte = pte_offset_kernel(pmd, vaddr);
207 pte_set_val(*pte, p, PAGE_READONLY);
208 }
209 #endif
210 }
211
paging_init(void)212 void __init paging_init(void)
213 {
214 unsigned long zones_size[MAX_NR_ZONES], vaddr;
215 int i;
216
217 empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
218 empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
219 for (i = 0; i < ARRAY_SIZE(zones_size); i++)
220 zones_size[i] = 0;
221
222 zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
223 (uml_physmem >> PAGE_SHIFT);
224 #ifdef CONFIG_HIGHMEM
225 zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
226 #endif
227 free_area_init(zones_size);
228
229 /*
230 * Fixed mappings, only the page table structure has to be
231 * created - mappings will be set by set_fixmap():
232 */
233 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
234 fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
235
236 fixaddr_user_init();
237
238 #ifdef CONFIG_HIGHMEM
239 init_highmem();
240 #endif
241 }
242
243 /*
244 * This can't do anything because nothing in the kernel image can be freed
245 * since it's not in kernel physical memory.
246 */
247
free_initmem(void)248 void free_initmem(void)
249 {
250 }
251
252 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)253 void free_initrd_mem(unsigned long start, unsigned long end)
254 {
255 if (start < end)
256 printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
257 (end - start) >> 10);
258 for (; start < end; start += PAGE_SIZE) {
259 ClearPageReserved(virt_to_page(start));
260 init_page_count(virt_to_page(start));
261 free_page(start);
262 totalram_pages++;
263 }
264 }
265 #endif
266
267 /* Allocate and free page tables. */
268
pgd_alloc(struct mm_struct * mm)269 pgd_t *pgd_alloc(struct mm_struct *mm)
270 {
271 pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
272
273 if (pgd) {
274 memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
275 memcpy(pgd + USER_PTRS_PER_PGD,
276 swapper_pg_dir + USER_PTRS_PER_PGD,
277 (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
278 }
279 return pgd;
280 }
281
pgd_free(struct mm_struct * mm,pgd_t * pgd)282 void pgd_free(struct mm_struct *mm, pgd_t *pgd)
283 {
284 free_page((unsigned long) pgd);
285 }
286
pte_alloc_one_kernel(struct mm_struct * mm,unsigned long address)287 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
288 {
289 pte_t *pte;
290
291 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
292 return pte;
293 }
294
pte_alloc_one(struct mm_struct * mm,unsigned long address)295 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
296 {
297 struct page *pte;
298
299 pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
300 if (pte)
301 pgtable_page_ctor(pte);
302 return pte;
303 }
304
305 #ifdef CONFIG_3_LEVEL_PGTABLES
pmd_alloc_one(struct mm_struct * mm,unsigned long address)306 pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
307 {
308 pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
309
310 if (pmd)
311 memset(pmd, 0, PAGE_SIZE);
312
313 return pmd;
314 }
315 #endif
316
uml_kmalloc(int size,int flags)317 void *uml_kmalloc(int size, int flags)
318 {
319 return kmalloc(size, flags);
320 }
321