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 /* It'd be good if these lines were in the standard header file. */
44 #define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
45 #define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn)
48 void (*copy_page
)(void *from
, void *to
);
49 void (*clear_page
)(void *to
);
53 int i
, total
= 0, reserved
= 0;
54 int shared
= 0, cached
= 0;
56 printk("Mem-info:\n");
58 printk("Free swap: %6ldkB\n", nr_swap_pages
<<(PAGE_SHIFT
-10));
62 if (PageReserved(mem_map
+i
))
64 else if (PageSwapCache(mem_map
+i
))
66 else if (page_count(mem_map
+i
))
67 shared
+= page_count(mem_map
+i
) - 1;
69 printk("%d pages of RAM\n",total
);
70 printk("%d reserved pages\n",reserved
);
71 printk("%d pages shared\n",shared
);
72 printk("%d pages swap cached\n",cached
);
76 static void set_pte_phys(unsigned long addr
, unsigned long phys
, pgprot_t prot
)
83 pgd
= pgd_offset_k(addr
);
89 pud
= pud_alloc(NULL
, pgd
, addr
);
95 pmd
= pmd_alloc(NULL
, pud
, addr
);
101 pte
= pte_offset_kernel(pmd
, addr
);
102 if (!pte_none(*pte
)) {
107 set_pte(pte
, pfn_pte(phys
>> PAGE_SHIFT
, prot
));
109 flush_tlb_one(get_asid(), addr
);
113 * As a performance optimization, other platforms preserve the fixmap mapping
114 * across a context switch, we don't presently do this, but this could be done
115 * in a similar fashion as to the wired TLB interface that sh64 uses (by way
116 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to
117 * give up a TLB entry for each mapping we want to preserve. While this may be
118 * viable for a small number of fixmaps, it's not particularly useful for
119 * everything and needs to be carefully evaluated. (ie, we may want this for
120 * the vsyscall page).
122 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
123 * in at __set_fixmap() time to determine the appropriate behavior to follow.
127 void __set_fixmap(enum fixed_addresses idx
, unsigned long phys
, pgprot_t prot
)
129 unsigned long address
= __fix_to_virt(idx
);
131 if (idx
>= __end_of_fixed_addresses
) {
136 set_pte_phys(address
, phys
, prot
);
138 #endif /* CONFIG_MMU */
140 /* References to section boundaries */
142 extern char _text
, _etext
, _edata
, __bss_start
, _end
;
143 extern char __init_begin
, __init_end
;
146 * paging_init() sets up the page tables
148 void __init
paging_init(void)
150 unsigned long zones_size
[MAX_NR_ZONES
] = { 0, };
153 * Setup some defaults for the zone sizes.. these should be safe
154 * regardless of distcontiguous memory or MMU settings.
156 zones_size
[ZONE_NORMAL
] = __MEMORY_SIZE
>> PAGE_SHIFT
;
157 #ifdef CONFIG_HIGHMEM
158 zones_size
[ZONE_HIGHMEM
] = 0 >> PAGE_SHIFT
;
163 * If we have an MMU, and want to be using it .. we need to adjust
164 * the zone sizes accordingly, in addition to turning it on.
167 /* We don't need to map the kernel through the TLB, as
168 * it is permanatly mapped using P1. So clear the
170 memset(swapper_pg_dir
, 0, sizeof(swapper_pg_dir
));
172 /* Turn on the MMU */
174 zones_size
[ZONE_NORMAL
] = MAX_LOW_PFN
- START_PFN
;
177 /* Set an initial value for the MMU.TTB so we don't have to
178 * check for a null value. */
179 set_TTB(swapper_pg_dir
);
181 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
183 * If we don't have CONFIG_MMU set and the processor in question
184 * still has an MMU, care needs to be taken to make sure it doesn't
185 * stay on.. Since the boot loader could have potentially already
186 * turned it on, and we clearly don't want it, we simply turn it off.
188 * We don't need to do anything special for the zone sizes, since the
189 * default values that were already configured up above should be
194 NODE_DATA(0)->node_mem_map
= NULL
;
195 free_area_init_node(0, NODE_DATA(0), zones_size
, __MEMORY_START
>> PAGE_SHIFT
, 0);
198 static struct kcore_list kcore_mem
, kcore_vmalloc
;
200 void __init
mem_init(void)
202 int codesize
, reservedpages
, datasize
, initsize
;
204 extern unsigned long memory_start
;
207 high_memory
= (void *)__va(MAX_LOW_PFN
* PAGE_SIZE
);
209 extern unsigned long memory_end
;
211 high_memory
= (void *)(memory_end
& PAGE_MASK
);
214 max_mapnr
= num_physpages
= MAP_NR(high_memory
) - MAP_NR(memory_start
);
216 /* clear the zero-page */
217 memset(empty_zero_page
, 0, PAGE_SIZE
);
218 __flush_wback_region(empty_zero_page
, PAGE_SIZE
);
221 * Setup wrappers for copy/clear_page(), these will get overridden
222 * later in the boot process if a better method is available.
225 copy_page
= copy_page_slow
;
226 clear_page
= clear_page_slow
;
228 copy_page
= copy_page_nommu
;
229 clear_page
= clear_page_nommu
;
232 /* this will put all low memory onto the freelists */
233 totalram_pages
+= free_all_bootmem_node(NODE_DATA(0));
235 for (tmp
= 0; tmp
< num_physpages
; tmp
++)
237 * Only count reserved RAM pages
239 if (PageReserved(mem_map
+tmp
))
242 codesize
= (unsigned long) &_etext
- (unsigned long) &_text
;
243 datasize
= (unsigned long) &_edata
- (unsigned long) &_etext
;
244 initsize
= (unsigned long) &__init_end
- (unsigned long) &__init_begin
;
246 kclist_add(&kcore_mem
, __va(0), max_low_pfn
<< PAGE_SHIFT
);
247 kclist_add(&kcore_vmalloc
, (void *)VMALLOC_START
,
248 VMALLOC_END
- VMALLOC_START
);
250 printk(KERN_INFO
"Memory: %luk/%luk available (%dk kernel code, "
251 "%dk reserved, %dk data, %dk init)\n",
252 (unsigned long) nr_free_pages() << (PAGE_SHIFT
-10),
253 max_mapnr
<< (PAGE_SHIFT
-10),
255 reservedpages
<< (PAGE_SHIFT
-10),
261 /* Initialize the vDSO */
265 void free_initmem(void)
269 addr
= (unsigned long)(&__init_begin
);
270 for (; addr
< (unsigned long)(&__init_end
); addr
+= PAGE_SIZE
) {
271 ClearPageReserved(virt_to_page(addr
));
272 init_page_count(virt_to_page(addr
));
276 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end
- &__init_begin
) >> 10);
279 #ifdef CONFIG_BLK_DEV_INITRD
280 void free_initrd_mem(unsigned long start
, unsigned long end
)
283 for (p
= start
; p
< end
; p
+= PAGE_SIZE
) {
284 ClearPageReserved(virt_to_page(p
));
285 init_page_count(virt_to_page(p
));
289 printk ("Freeing initrd memory: %ldk freed\n", (end
- start
) >> 10);