ARM: mmp: fix potential NULL dereference
[linux/fpc-iii.git] / arch / score / mm / init.c
blobcee6bce1e30c3663490e05d66725f89c907e62a9
1 /*
2 * arch/score/mm/init.c
4 * Score Processor version.
6 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
7 * Lennox Wu <lennox.wu@sunplusct.com>
8 * Chen Liqin <liqin.chen@sunplusct.com>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, see the file COPYING, or write
22 * to the Free Software Foundation, Inc.,
23 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
26 #include <linux/errno.h>
27 #include <linux/bootmem.h>
28 #include <linux/kernel.h>
29 #include <linux/gfp.h>
30 #include <linux/init.h>
31 #include <linux/mm.h>
32 #include <linux/mman.h>
33 #include <linux/pagemap.h>
34 #include <linux/proc_fs.h>
35 #include <linux/sched.h>
36 #include <linux/initrd.h>
38 #include <asm/sections.h>
39 #include <asm/tlb.h>
41 unsigned long empty_zero_page;
42 EXPORT_SYMBOL_GPL(empty_zero_page);
44 static struct kcore_list kcore_mem, kcore_vmalloc;
46 static unsigned long setup_zero_page(void)
48 struct page *page;
50 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, 0);
51 if (!empty_zero_page)
52 panic("Oh boy, that early out of memory?");
54 page = virt_to_page((void *) empty_zero_page);
55 SetPageReserved(page);
57 return 1UL;
60 #ifndef CONFIG_NEED_MULTIPLE_NODES
61 int page_is_ram(unsigned long pagenr)
63 if (pagenr >= min_low_pfn && pagenr < max_low_pfn)
64 return 1;
65 else
66 return 0;
69 void __init paging_init(void)
71 unsigned long max_zone_pfns[MAX_NR_ZONES];
72 unsigned long lastpfn;
74 pagetable_init();
75 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
76 lastpfn = max_low_pfn;
77 free_area_init_nodes(max_zone_pfns);
80 void __init mem_init(void)
82 unsigned long codesize, reservedpages, datasize, initsize;
83 unsigned long tmp, ram = 0;
85 high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
86 totalram_pages += free_all_bootmem();
87 totalram_pages -= setup_zero_page(); /* Setup zeroed pages. */
88 reservedpages = 0;
90 for (tmp = 0; tmp < max_low_pfn; tmp++)
91 if (page_is_ram(tmp)) {
92 ram++;
93 if (PageReserved(pfn_to_page(tmp)))
94 reservedpages++;
97 num_physpages = ram;
98 codesize = (unsigned long) &_etext - (unsigned long) &_text;
99 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
100 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
102 printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
103 "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
104 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
105 ram << (PAGE_SHIFT-10), codesize >> 10,
106 reservedpages << (PAGE_SHIFT-10), datasize >> 10,
107 initsize >> 10,
108 totalhigh_pages << (PAGE_SHIFT-10));
110 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
112 static void free_init_pages(const char *what, unsigned long begin, unsigned long end)
114 unsigned long pfn;
116 for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
117 struct page *page = pfn_to_page(pfn);
118 void *addr = phys_to_virt(PFN_PHYS(pfn));
120 ClearPageReserved(page);
121 init_page_count(page);
122 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
123 __free_page(page);
124 totalram_pages++;
126 printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
129 #ifdef CONFIG_BLK_DEV_INITRD
130 void free_initrd_mem(unsigned long start, unsigned long end)
132 free_init_pages("initrd memory",
133 virt_to_phys((void *) start),
134 virt_to_phys((void *) end));
136 #endif
138 void __init_refok free_initmem(void)
140 free_init_pages("unused kernel memory",
141 __pa(&__init_begin),
142 __pa(&__init_end));
145 unsigned long pgd_current;
147 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
150 * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
151 * are constants. So we use the variants from asm-offset.h until that gcc
152 * will officially be retired.
154 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PTE_ORDER);
155 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);