1 /* MN10300 Memory management initialisation
2 *
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Modified by David Howells (dhowells@redhat.com)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
11 */
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/mman.h>
20 #include <linux/fs.h>
21 #include <linux/mm.h>
22 #include <linux/swap.h>
23 #include <linux/smp.h>
24 #include <linux/init.h>
25 #include <linux/initrd.h>
26 #include <linux/highmem.h>
27 #include <linux/pagemap.h>
28 #include <linux/bootmem.h>
29 #include <linux/gfp.h>
30
31 #include <asm/processor.h>
32 #include <asm/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/pgalloc.h>
35 #include <asm/dma.h>
36 #include <asm/tlb.h>
37 #include <asm/sections.h>
38
39 unsigned long highstart_pfn, highend_pfn;
40
41 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
42 static struct vm_struct user_iomap_vm;
43 #endif
44
45 /*
46 * set up paging
47 */
paging_init(void)48 void __init paging_init(void)
49 {
50 unsigned long zones_size[MAX_NR_ZONES] = {0,};
51 pte_t *ppte;
52 int loop;
53
54 /* main kernel space -> RAM mapping is handled as 1:1 transparent by
55 * the MMU */
56 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
57 memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
58
59 /* load the VMALLOC area PTE table addresses into the kernel PGD */
60 ppte = kernel_vmalloc_ptes;
61 for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
62 loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
63 loop++
64 ) {
65 set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
66 ppte += PAGE_SIZE / sizeof(pte_t);
67 }
68
69 /* declare the sizes of the RAM zones (only use the normal zone) */
70 zones_size[ZONE_NORMAL] =
71 contig_page_data.bdata->node_low_pfn -
72 contig_page_data.bdata->node_min_pfn;
73
74 /* pass the memory from the bootmem allocator to the main allocator */
75 free_area_init(zones_size);
76
77 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
78 /* The Atomic Operation Unit registers need to be mapped to userspace
79 * for all processes. The following uses vm_area_register_early() to
80 * reserve the first page of the vmalloc area and sets the pte for that
81 * page.
82 *
83 * glibc hardcodes this virtual mapping, so we're pretty much stuck with
84 * it from now on.
85 */
86 user_iomap_vm.flags = VM_USERMAP;
87 user_iomap_vm.size = 1 << PAGE_SHIFT;
88 vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
89 ppte = kernel_vmalloc_ptes;
90 set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
91 PAGE_USERIO));
92 #endif
93
94 local_flush_tlb_all();
95 }
96
97 /*
98 * transfer all the memory from the bootmem allocator to the runtime allocator
99 */
mem_init(void)100 void __init mem_init(void)
101 {
102 int codesize, reservedpages, datasize, initsize;
103 int tmp;
104
105 BUG_ON(!mem_map);
106
107 #define START_PFN (contig_page_data.bdata->node_min_pfn)
108 #define MAX_LOW_PFN (contig_page_data.bdata->node_low_pfn)
109
110 max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
111 high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
112
113 /* clear the zero-page */
114 memset(empty_zero_page, 0, PAGE_SIZE);
115
116 /* this will put all low memory onto the freelists */
117 totalram_pages += free_all_bootmem();
118
119 reservedpages = 0;
120 for (tmp = 0; tmp < num_physpages; tmp++)
121 if (PageReserved(&mem_map[tmp]))
122 reservedpages++;
123
124 codesize = (unsigned long) &_etext - (unsigned long) &_stext;
125 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
126 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
127
128 printk(KERN_INFO
129 "Memory: %luk/%luk available"
130 " (%dk kernel code, %dk reserved, %dk data, %dk init,"
131 " %ldk highmem)\n",
132 nr_free_pages() << (PAGE_SHIFT - 10),
133 max_mapnr << (PAGE_SHIFT - 10),
134 codesize >> 10,
135 reservedpages << (PAGE_SHIFT - 10),
136 datasize >> 10,
137 initsize >> 10,
138 totalhigh_pages << (PAGE_SHIFT - 10));
139 }
140
141 /*
142 *
143 */
free_init_pages(char * what,unsigned long begin,unsigned long end)144 void free_init_pages(char *what, unsigned long begin, unsigned long end)
145 {
146 unsigned long addr;
147
148 for (addr = begin; addr < end; addr += PAGE_SIZE) {
149 ClearPageReserved(virt_to_page(addr));
150 init_page_count(virt_to_page(addr));
151 memset((void *) addr, 0xcc, PAGE_SIZE);
152 free_page(addr);
153 totalram_pages++;
154 }
155 printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
156 }
157
158 /*
159 * recycle memory containing stuff only required for initialisation
160 */
free_initmem(void)161 void free_initmem(void)
162 {
163 free_init_pages("unused kernel memory",
164 (unsigned long) &__init_begin,
165 (unsigned long) &__init_end);
166 }
167
168 /*
169 * dispose of the memory on which the initial ramdisk resided
170 */
171 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)172 void free_initrd_mem(unsigned long start, unsigned long end)
173 {
174 free_init_pages("initrd memory", start, end);
175 }
176 #endif
177