1/*
2 * Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
3 * Licensed under the GPL
4 */
5
6#include "linux/stddef.h"
7#include "linux/kernel.h"
8#include "linux/mm.h"
9#include "linux/bootmem.h"
10#include "linux/swap.h"
11#include "linux/highmem.h"
12#include "linux/gfp.h"
13#include "asm/page.h"
14#include "asm/fixmap.h"
15#include "asm/pgalloc.h"
16#include "kern_util.h"
17#include "as-layout.h"
18#include "kern.h"
19#include "mem_user.h"
20#include "uml_uaccess.h"
21#include "os.h"
22#include "linux/types.h"
23#include "linux/string.h"
24#include "init.h"
25#include "kern_constants.h"
26
27/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
28unsigned long *empty_zero_page = NULL;
29/* allocated in paging_init and unchanged thereafter */
30unsigned long *empty_bad_page = NULL;
31pgd_t swapper_pg_dir[PTRS_PER_PGD];
32unsigned long long highmem;
33int kmalloc_ok = 0;
34
35static unsigned long brk_end;
36
37void unmap_physmem(void)
38{
39	os_unmap_memory((void *) brk_end, uml_reserved - brk_end);
40}
41
42static void map_cb(void *unused)
43{
44	map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
45}
46
47#ifdef CONFIG_HIGHMEM
48static void setup_highmem(unsigned long highmem_start,
49			  unsigned long highmem_len)
50{
51	struct page *page;
52	unsigned long highmem_pfn;
53	int i;
54
55	highmem_pfn = __pa(highmem_start) >> PAGE_SHIFT;
56	for(i = 0; i < highmem_len >> PAGE_SHIFT; i++){
57		page = &mem_map[highmem_pfn + i];
58		ClearPageReserved(page);
59		init_page_count(page);
60		__free_page(page);
61	}
62}
63#endif
64
65void mem_init(void)
66{
67	/* clear the zero-page */
68	memset((void *) empty_zero_page, 0, PAGE_SIZE);
69
70	/* Map in the area just after the brk now that kmalloc is about
71	 * to be turned on.
72	 */
73	brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
74	map_cb(NULL);
75	initial_thread_cb(map_cb, NULL);
76	free_bootmem(__pa(brk_end), uml_reserved - brk_end);
77	uml_reserved = brk_end;
78
79	/* this will put all low memory onto the freelists */
80	totalram_pages = free_all_bootmem();
81	max_low_pfn = totalram_pages;
82#ifdef CONFIG_HIGHMEM
83	totalhigh_pages = highmem >> PAGE_SHIFT;
84	totalram_pages += totalhigh_pages;
85#endif
86	num_physpages = totalram_pages;
87	max_pfn = totalram_pages;
88	printk(KERN_INFO "Memory: %luk available\n",
89	       (unsigned long) nr_free_pages() << (PAGE_SHIFT-10));
90	kmalloc_ok = 1;
91
92#ifdef CONFIG_HIGHMEM
93	setup_highmem(end_iomem, highmem);
94#endif
95}
96
97/*
98 * Create a page table and place a pointer to it in a middle page
99 * directory entry.
100 */
101static void __init one_page_table_init(pmd_t *pmd)
102{
103	if (pmd_none(*pmd)) {
104		pte_t *pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
105		set_pmd(pmd, __pmd(_KERNPG_TABLE +
106					   (unsigned long) __pa(pte)));
107		if (pte != pte_offset_kernel(pmd, 0))
108			BUG();
109	}
110}
111
112static void __init one_md_table_init(pud_t *pud)
113{
114#ifdef CONFIG_3_LEVEL_PGTABLES
115	pmd_t *pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
116	set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
117	if (pmd_table != pmd_offset(pud, 0))
118		BUG();
119#endif
120}
121
122static void __init fixrange_init(unsigned long start, unsigned long end,
123				 pgd_t *pgd_base)
124{
125	pgd_t *pgd;
126	pud_t *pud;
127	pmd_t *pmd;
128	int i, j;
129	unsigned long vaddr;
130
131	vaddr = start;
132	i = pgd_index(vaddr);
133	j = pmd_index(vaddr);
134	pgd = pgd_base + i;
135
136	for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
137		pud = pud_offset(pgd, vaddr);
138		if (pud_none(*pud))
139			one_md_table_init(pud);
140		pmd = pmd_offset(pud, vaddr);
141		for (; (j < PTRS_PER_PMD) && (vaddr != end); pmd++, j++) {
142			one_page_table_init(pmd);
143			vaddr += PMD_SIZE;
144		}
145		j = 0;
146	}
147}
148
149#ifdef CONFIG_HIGHMEM
150pte_t *kmap_pte;
151pgprot_t kmap_prot;
152
153#define kmap_get_fixmap_pte(vaddr)					\
154	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)),\
155 			  (vaddr)), (vaddr))
156
157static void __init kmap_init(void)
158{
159	unsigned long kmap_vstart;
160
161	/* cache the first kmap pte */
162	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
163	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
164
165	kmap_prot = PAGE_KERNEL;
166}
167
168static void init_highmem(void)
169{
170	pgd_t *pgd;
171	pud_t *pud;
172	pmd_t *pmd;
173	pte_t *pte;
174	unsigned long vaddr;
175
176	/*
177	 * Permanent kmaps:
178	 */
179	vaddr = PKMAP_BASE;
180	fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
181
182	pgd = swapper_pg_dir + pgd_index(vaddr);
183	pud = pud_offset(pgd, vaddr);
184	pmd = pmd_offset(pud, vaddr);
185	pte = pte_offset_kernel(pmd, vaddr);
186	pkmap_page_table = pte;
187
188	kmap_init();
189}
190#endif /* CONFIG_HIGHMEM */
191
192static void __init fixaddr_user_init( void)
193{
194#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
195	long size = FIXADDR_USER_END - FIXADDR_USER_START;
196	pgd_t *pgd;
197	pud_t *pud;
198	pmd_t *pmd;
199	pte_t *pte;
200	unsigned long paddr, vaddr = FIXADDR_USER_START;
201
202	if (  ! size )
203		return;
204
205	fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
206	paddr = (unsigned long)alloc_bootmem_low_pages( size);
207	memcpy( (void *)paddr, (void *)FIXADDR_USER_START, size);
208	paddr = __pa(paddr);
209	for ( ; size > 0; size-=PAGE_SIZE, vaddr+=PAGE_SIZE, paddr+=PAGE_SIZE){
210		pgd = swapper_pg_dir + pgd_index(vaddr);
211		pud = pud_offset(pgd, vaddr);
212		pmd = pmd_offset(pud, vaddr);
213		pte = pte_offset_kernel(pmd, vaddr);
214		pte_set_val( (*pte), paddr, PAGE_READONLY);
215	}
216#endif
217}
218
219void __init paging_init(void)
220{
221	unsigned long zones_size[MAX_NR_ZONES], vaddr;
222	int i;
223
224	empty_zero_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
225	empty_bad_page = (unsigned long *) alloc_bootmem_low_pages(PAGE_SIZE);
226	for(i = 0; i < ARRAY_SIZE(zones_size); i++)
227		zones_size[i] = 0;
228
229	zones_size[ZONE_NORMAL] = (end_iomem >> PAGE_SHIFT) -
230		(uml_physmem >> PAGE_SHIFT);
231#ifdef CONFIG_HIGHMEM
232	zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
233#endif
234	free_area_init(zones_size);
235
236	/*
237	 * Fixed mappings, only the page table structure has to be
238	 * created - mappings will be set by set_fixmap():
239	 */
240	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
241	fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
242
243	fixaddr_user_init();
244
245#ifdef CONFIG_HIGHMEM
246	init_highmem();
247#endif
248}
249
250struct page *arch_validate(struct page *page, gfp_t mask, int order)
251{
252	unsigned long addr, zero = 0;
253	int i;
254
255 again:
256	if(page == NULL)
257		return page;
258	if(PageHighMem(page))
259		return page;
260
261	addr = (unsigned long) page_address(page);
262	for(i = 0; i < (1 << order); i++){
263		current->thread.fault_addr = (void *) addr;
264		if(__do_copy_to_user((void __user *) addr, &zero,
265				     sizeof(zero),
266				     &current->thread.fault_addr,
267				     &current->thread.fault_catcher)){
268			if(!(mask & __GFP_WAIT))
269				return NULL;
270			else break;
271		}
272		addr += PAGE_SIZE;
273	}
274
275	if(i == (1 << order))
276		return page;
277	page = alloc_pages(mask, order);
278	goto again;
279}
280
281/* This can't do anything because nothing in the kernel image can be freed
282 * since it's not in kernel physical memory.
283 */
284
285void free_initmem(void)
286{
287}
288
289#ifdef CONFIG_BLK_DEV_INITRD
290void free_initrd_mem(unsigned long start, unsigned long end)
291{
292	if (start < end)
293		printk ("Freeing initrd memory: %ldk freed\n",
294			(end - start) >> 10);
295	for (; start < end; start += PAGE_SIZE) {
296		ClearPageReserved(virt_to_page(start));
297		init_page_count(virt_to_page(start));
298		free_page(start);
299		totalram_pages++;
300	}
301}
302#endif
303
304void show_mem(void)
305{
306	int pfn, total = 0, reserved = 0;
307	int shared = 0, cached = 0;
308	int highmem = 0;
309	struct page *page;
310
311	printk("Mem-info:\n");
312	show_free_areas();
313	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
314	pfn = max_mapnr;
315	while(pfn-- > 0) {
316		page = pfn_to_page(pfn);
317		total++;
318		if(PageHighMem(page))
319			highmem++;
320		if(PageReserved(page))
321			reserved++;
322		else if(PageSwapCache(page))
323			cached++;
324		else if(page_count(page))
325			shared += page_count(page) - 1;
326	}
327	printk("%d pages of RAM\n", total);
328	printk("%d pages of HIGHMEM\n", highmem);
329	printk("%d reserved pages\n", reserved);
330	printk("%d pages shared\n", shared);
331	printk("%d pages swap cached\n", cached);
332}
333
334/*
335 * Allocate and free page tables.
336 */
337
338pgd_t *pgd_alloc(struct mm_struct *mm)
339{
340	pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
341
342	if (pgd) {
343		memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
344		memcpy(pgd + USER_PTRS_PER_PGD,
345		       swapper_pg_dir + USER_PTRS_PER_PGD,
346		       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
347	}
348	return pgd;
349}
350
351void pgd_free(pgd_t *pgd)
352{
353	free_page((unsigned long) pgd);
354}
355
356pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
357{
358	pte_t *pte;
359
360	pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
361	return pte;
362}
363
364struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
365{
366	struct page *pte;
367
368	pte = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
369	return pte;
370}
371