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
41void __init mem_init(void)
42{
43	/* clear the zero-page */
44	memset(empty_zero_page, 0, PAGE_SIZE);
45
46	/* Map in the area just after the brk now that kmalloc is about
47	 * to be turned on.
48	 */
49	brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
50	map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
51	free_bootmem(__pa(brk_end), uml_reserved - brk_end);
52	uml_reserved = brk_end;
53
54	/* this will put all low memory onto the freelists */
55	free_all_bootmem();
56	max_low_pfn = totalram_pages;
57	max_pfn = totalram_pages;
58	mem_init_print_info(NULL);
59	kmalloc_ok = 1;
60}
61
62/*
63 * Create a page table and place a pointer to it in a middle page
64 * directory entry.
65 */
66static void __init one_page_table_init(pmd_t *pmd)
67{
68	if (pmd_none(*pmd)) {
69		pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
70		set_pmd(pmd, __pmd(_KERNPG_TABLE +
71					   (unsigned long) __pa(pte)));
72		if (pte != pte_offset_kernel(pmd, 0))
73			BUG();
74	}
75}
76
77static void __init one_md_table_init(pud_t *pud)
78{
79#ifdef CONFIG_3_LEVEL_PGTABLES
80	pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
81	set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
82	if (pmd_table != pmd_offset(pud, 0))
83		BUG();
84#endif
85}
86
87static void __init fixrange_init(unsigned long start, unsigned long end,
88				 pgd_t *pgd_base)
89{
90	pgd_t *pgd;
91	pud_t *pud;
92	pmd_t *pmd;
93	int i, j;
94	unsigned long vaddr;
95
96	vaddr = start;
97	i = pgd_index(vaddr);
98	j = pmd_index(vaddr);
99	pgd = pgd_base + i;
100
101	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
102		pud = pud_offset(pgd, vaddr);
103		if (pud_none(*pud))
104			one_md_table_init(pud);
105		pmd = pmd_offset(pud, vaddr);
106		for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
107			one_page_table_init(pmd);
108			vaddr += PMD_SIZE;
109		}
110		j = 0;
111	}
112}
113
114static void __init fixaddr_user_init( void)
115{
116#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
117	long size = FIXADDR_USER_END - FIXADDR_USER_START;
118	pgd_t *pgd;
119	pud_t *pud;
120	pmd_t *pmd;
121	pte_t *pte;
122	phys_t p;
123	unsigned long v, vaddr = FIXADDR_USER_START;
124
125	if (!size)
126		return;
127
128	fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
129	v = (unsigned long) alloc_bootmem_low_pages(size);
130	memcpy((void *) v , (void *) FIXADDR_USER_START, size);
131	p = __pa(v);
132	for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
133		      p += PAGE_SIZE) {
134		pgd = swapper_pg_dir + pgd_index(vaddr);
135		pud = pud_offset(pgd, vaddr);
136		pmd = pmd_offset(pud, vaddr);
137		pte = pte_offset_kernel(pmd, vaddr);
138		pte_set_val(*pte, p, PAGE_READONLY);
139	}
140#endif
141}
142
143void __init paging_init(void)
144{
145	unsigned long zones_size[MAX_NR_ZONES], vaddr;
146	int i;
147
148	empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
149	empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
150	for (i = 0; i < ARRAY_SIZE(zones_size); i++)
151		zones_size[i] = 0;
152
153	zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
154		(uml_physmem >> PAGE_SHIFT);
155	free_area_init(zones_size);
156
157	/*
158	 * Fixed mappings, only the page table structure has to be
159	 * created - mappings will be set by set_fixmap():
160	 */
161	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
162	fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
163
164	fixaddr_user_init();
165}
166
167/*
168 * This can't do anything because nothing in the kernel image can be freed
169 * since it's not in kernel physical memory.
170 */
171
172void free_initmem(void)
173{
174}
175
176#ifdef CONFIG_BLK_DEV_INITRD
177void free_initrd_mem(unsigned long start, unsigned long end)
178{
179	free_reserved_area((void *)start, (void *)end, -1, "initrd");
180}
181#endif
182
183/* Allocate and free page tables. */
184
185pgd_t *pgd_alloc(struct mm_struct *mm)
186{
187	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
188
189	if (pgd) {
190		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
191		memcpy(pgd + USER_PTRS_PER_PGD,
192		       swapper_pg_dir + USER_PTRS_PER_PGD,
193		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
194	}
195	return pgd;
196}
197
198void pgd_free(struct mm_struct *mm, pgd_t *pgd)
199{
200	free_page((unsigned long) pgd);
201}
202
203pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
204{
205	pte_t *pte;
206
207	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
208	return pte;
209}
210
211pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
212{
213	struct page *pte;
214
215	pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
216	if (!pte)
217		return NULL;
218	if (!pgtable_page_ctor(pte)) {
219		__free_page(pte);
220		return NULL;
221	}
222	return pte;
223}
224
225#ifdef CONFIG_3_LEVEL_PGTABLES
226pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
227{
228	pmd_t *pmd = (pmd_t *) __get_free_page(GFP_KERNEL);
229
230	if (pmd)
231		memset(pmd, 0, PAGE_SIZE);
232
233	return pmd;
234}
235#endif
236
237void *uml_kmalloc(int size, int flags)
238{
239	return kmalloc(size, flags);
240}
241