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, 2004 Paul Mundt
8 * Based on linux/arch/i386/mm/init.c:
9 * Copyright (C) 1995 Linus Torvalds
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>
21 #include <linux/swap.h>
22 #include <linux/smp.h>
23 #include <linux/init.h>
24 #include <linux/highmem.h>
25 #include <linux/bootmem.h>
26 #include <linux/pagemap.h>
27 #include <linux/proc_fs.h>
28 #include <asm/processor.h>
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/pgalloc.h>
33 #include <asm/mmu_context.h>
36 #include <asm/cacheflush.h>
37 #include <asm/cache.h>
39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
40 pgd_t swapper_pg_dir[PTRS_PER_PGD];
43 * Cache of MMU context last used.
45 unsigned long mmu_context_cache = NO_CONTEXT;
48 /* It'd be good if these lines were in the standard header file. */
49 #define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
50 #define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn)
53 void (*copy_page)(void *from, void *to);
54 void (*clear_page)(void *to);
58 int i, total = 0, reserved = 0;
59 int shared = 0, cached = 0;
61 printk("Mem-info:\n");
63 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
67 if (PageReserved(mem_map+i))
69 else if (PageSwapCache(mem_map+i))
71 else if (page_count(mem_map+i))
72 shared += page_count(mem_map+i) - 1;
74 printk("%d pages of RAM\n",total);
75 printk("%d reserved pages\n",reserved);
76 printk("%d pages shared\n",shared);
77 printk("%d pages swap cached\n",cached);
81 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
88 pgd = pgd_offset_k(addr);
94 pud = pud_alloc(NULL, pgd, addr);
100 pmd = pmd_alloc(NULL, pud, addr);
101 if (unlikely(!pmd)) {
106 pte = pte_offset_kernel(pmd, addr);
107 if (!pte_none(*pte)) {
112 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
114 __flush_tlb_page(get_asid(), addr);
118 * As a performance optimization, other platforms preserve the fixmap mapping
119 * across a context switch, we don't presently do this, but this could be done
120 * in a similar fashion as to the wired TLB interface that sh64 uses (by way
121 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to
122 * give up a TLB entry for each mapping we want to preserve. While this may be
123 * viable for a small number of fixmaps, it's not particularly useful for
124 * everything and needs to be carefully evaluated. (ie, we may want this for
125 * the vsyscall page).
127 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
128 * in at __set_fixmap() time to determine the appropriate behavior to follow.
132 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
134 unsigned long address = __fix_to_virt(idx);
136 if (idx >= __end_of_fixed_addresses) {
141 set_pte_phys(address, phys, prot);
143 #endif /* CONFIG_MMU */
145 /* References to section boundaries */
147 extern char _text, _etext, _edata, __bss_start, _end;
148 extern char __init_begin, __init_end;
151 * paging_init() sets up the page tables
153 void __init paging_init(void)
155 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
158 * Setup some defaults for the zone sizes.. these should be safe
159 * regardless of distcontiguous memory or MMU settings.
161 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
162 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT;
163 #ifdef CONFIG_HIGHMEM
164 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT;
169 * If we have an MMU, and want to be using it .. we need to adjust
170 * the zone sizes accordingly, in addition to turning it on.
173 unsigned long max_dma, low, start_pfn;
175 /* We don't need to map the kernel through the TLB, as
176 * it is permanatly mapped using P1. So clear the
178 memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
180 /* Turn on the MMU */
183 /* Fixup the zone sizes */
184 start_pfn = START_PFN;
185 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
189 zones_size[ZONE_DMA] = low - start_pfn;
190 zones_size[ZONE_NORMAL] = 0;
192 zones_size[ZONE_DMA] = max_dma - start_pfn;
193 zones_size[ZONE_NORMAL] = low - max_dma;
197 /* Set an initial value for the MMU.TTB so we don't have to
198 * check for a null value. */
199 set_TTB(swapper_pg_dir);
201 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
203 * If we don't have CONFIG_MMU set and the processor in question
204 * still has an MMU, care needs to be taken to make sure it doesn't
205 * stay on.. Since the boot loader could have potentially already
206 * turned it on, and we clearly don't want it, we simply turn it off.
208 * We don't need to do anything special for the zone sizes, since the
209 * default values that were already configured up above should be
214 NODE_DATA(0)->node_mem_map = NULL;
215 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
218 static struct kcore_list kcore_mem, kcore_vmalloc;
220 void __init mem_init(void)
222 int codesize, reservedpages, datasize, initsize;
224 extern unsigned long memory_start;
227 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
229 extern unsigned long memory_end;
231 high_memory = (void *)(memory_end & PAGE_MASK);
234 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start);
236 /* clear the zero-page */
237 memset(empty_zero_page, 0, PAGE_SIZE);
238 __flush_wback_region(empty_zero_page, PAGE_SIZE);
241 * Setup wrappers for copy/clear_page(), these will get overridden
242 * later in the boot process if a better method is available.
245 copy_page = copy_page_slow;
246 clear_page = clear_page_slow;
248 copy_page = copy_page_nommu;
249 clear_page = clear_page_nommu;
252 /* this will put all low memory onto the freelists */
253 totalram_pages += free_all_bootmem_node(NODE_DATA(0));
255 for (tmp = 0; tmp < num_physpages; tmp++)
257 * Only count reserved RAM pages
259 if (PageReserved(mem_map+tmp))
262 codesize = (unsigned long) &_etext - (unsigned long) &_text;
263 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
264 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
266 kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
267 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
268 VMALLOC_END - VMALLOC_START);
270 printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
271 "%dk reserved, %dk data, %dk init)\n",
272 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
273 max_mapnr << (PAGE_SHIFT-10),
275 reservedpages << (PAGE_SHIFT-10),
281 /* Initialize the vDSO */
285 void free_initmem(void)
289 addr = (unsigned long)(&__init_begin);
290 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
291 ClearPageReserved(virt_to_page(addr));
292 init_page_count(virt_to_page(addr));
296 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
299 #ifdef CONFIG_BLK_DEV_INITRD
300 void free_initrd_mem(unsigned long start, unsigned long end)
303 for (p = start; p < end; p += PAGE_SIZE) {
304 ClearPageReserved(virt_to_page(p));
305 init_page_count(virt_to_page(p));
309 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);