1 /* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $
3 * linux/arch/sh/mm/init.c
5 * Copyright (C) 1999 Niibe Yutaka
6 * Copyright (C) 2002 Paul Mundt
8 * Based on linux/arch/i386/mm/init.c:
9 * Copyright (C) 1995 Linus Torvalds
12 #include <linux/config.h>
13 #include <linux/signal.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/ptrace.h>
20 #include <linux/mman.h>
22 #include <linux/swap.h>
23 #include <linux/smp.h>
24 #include <linux/init.h>
25 #include <linux/highmem.h>
26 #include <linux/bootmem.h>
27 #include <linux/pagemap.h>
29 #include <asm/processor.h>
30 #include <asm/system.h>
31 #include <asm/uaccess.h>
32 #include <asm/pgtable.h>
33 #include <asm/pgalloc.h>
34 #include <asm/mmu_context.h>
37 #include <asm/cacheflush.h>
38 #include <asm/cache.h>
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41 pgd_t swapper_pg_dir[PTRS_PER_PGD];
44 * Cache of MMU context last used.
46 unsigned long mmu_context_cache = NO_CONTEXT;
49 /* It'd be good if these lines were in the standard header file. */
50 #define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
51 #define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn)
54 #ifdef CONFIG_DISCONTIGMEM
55 pg_data_t discontig_page_data[MAX_NUMNODES];
56 bootmem_data_t discontig_node_bdata[MAX_NUMNODES];
59 void (*copy_page)(void *from, void *to);
60 void (*clear_page)(void *to);
64 int i, total = 0, reserved = 0;
65 int shared = 0, cached = 0;
67 printk("Mem-info:\n");
69 printk("Free swap: %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
73 if (PageReserved(mem_map+i))
75 else if (PageSwapCache(mem_map+i))
77 else if (page_count(mem_map+i))
78 shared += page_count(mem_map+i) - 1;
80 printk("%d pages of RAM\n",total);
81 printk("%d reserved pages\n",reserved);
82 printk("%d pages shared\n",shared);
83 printk("%d pages swap cached\n",cached);
86 /* References to section boundaries */
88 extern char _text, _etext, _edata, __bss_start, _end;
89 extern char __init_begin, __init_end;
92 * paging_init() sets up the page tables
94 * This routines also unmaps the page at virtual kernel address 0, so
95 * that we can trap those pesky NULL-reference errors in the kernel.
97 void __init paging_init(void)
99 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
102 * Setup some defaults for the zone sizes.. these should be safe
103 * regardless of distcontiguous memory or MMU settings.
105 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
106 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT;
107 #ifdef CONFIG_HIGHMEM
108 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT;
113 * If we have an MMU, and want to be using it .. we need to adjust
114 * the zone sizes accordingly, in addition to turning it on.
117 unsigned long max_dma, low, start_pfn;
121 /* We don't need kernel mapping as hardware support that. */
122 pg_dir = swapper_pg_dir;
124 for (i = 0; i < PTRS_PER_PGD; i++)
125 pgd_val(pg_dir[i]) = 0;
127 /* Turn on the MMU */
130 /* Fixup the zone sizes */
131 start_pfn = START_PFN;
132 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
136 zones_size[ZONE_DMA] = low - start_pfn;
137 zones_size[ZONE_NORMAL] = 0;
139 zones_size[ZONE_DMA] = max_dma - start_pfn;
140 zones_size[ZONE_NORMAL] = low - max_dma;
144 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
146 * If we don't have CONFIG_MMU set and the processor in question
147 * still has an MMU, care needs to be taken to make sure it doesn't
148 * stay on.. Since the boot loader could have potentially already
149 * turned it on, and we clearly don't want it, we simply turn it off.
151 * We don't need to do anything special for the zone sizes, since the
152 * default values that were already configured up above should be
158 free_area_init_node(0, NODE_DATA(0), 0, zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
159 /* XXX: MRB-remove - this doesn't seem sane, should this be done somewhere else ?*/
160 mem_map = NODE_DATA(0)->node_mem_map;
162 #ifdef CONFIG_DISCONTIGMEM
164 * And for discontig, do some more fixups on the zone sizes..
166 zones_size[ZONE_DMA] = __MEMORY_SIZE_2ND >> PAGE_SHIFT;
167 zones_size[ZONE_NORMAL] = 0;
168 free_area_init_node(1, NODE_DATA(1), 0, zones_size, __MEMORY_START_2ND >> PAGE_SHIFT, 0);
172 void __init mem_init(void)
174 extern unsigned long empty_zero_page[1024];
175 int codesize, reservedpages, datasize, initsize;
177 extern unsigned long memory_start;
180 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
182 extern unsigned long memory_end;
184 high_memory = (void *)(memory_end & PAGE_MASK);
187 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start);
189 /* clear the zero-page */
190 memset(empty_zero_page, 0, PAGE_SIZE);
191 __flush_wback_region(empty_zero_page, PAGE_SIZE);
194 * Setup wrappers for copy/clear_page(), these will get overridden
195 * later in the boot process if a better method is available.
197 copy_page = copy_page_slow;
198 clear_page = clear_page_slow;
200 /* this will put all low memory onto the freelists */
201 totalram_pages += free_all_bootmem_node(NODE_DATA(0));
202 #ifdef CONFIG_DISCONTIGMEM
203 totalram_pages += free_all_bootmem_node(NODE_DATA(1));
206 for (tmp = 0; tmp < num_physpages; tmp++)
208 * Only count reserved RAM pages
210 if (PageReserved(mem_map+tmp))
213 codesize = (unsigned long) &_etext - (unsigned long) &_text;
214 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
215 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
217 printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n",
218 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
219 max_mapnr << (PAGE_SHIFT-10),
221 reservedpages << (PAGE_SHIFT-10),
228 void free_initmem(void)
232 addr = (unsigned long)(&__init_begin);
233 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
234 ClearPageReserved(virt_to_page(addr));
235 set_page_count(virt_to_page(addr), 1);
239 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
242 #ifdef CONFIG_BLK_DEV_INITRD
243 void free_initrd_mem(unsigned long start, unsigned long end)
246 for (p = start; p < end; p += PAGE_SIZE) {
247 ClearPageReserved(virt_to_page(p));
248 set_page_count(virt_to_page(p), 1);
252 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);