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-rw-r--r--arch/sh/mm/init.c313
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diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
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1/* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $
2 *
3 * linux/arch/sh/mm/init.c
4 *
5 * Copyright (C) 1999 Niibe Yutaka
6 * Copyright (C) 2002, 2004 Paul Mundt
7 *
8 * Based on linux/arch/i386/mm/init.c:
9 * Copyright (C) 1995 Linus Torvalds
10 */
11
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>
21#include <linux/mm.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>
28
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>
35#include <asm/io.h>
36#include <asm/tlb.h>
37#include <asm/cacheflush.h>
38#include <asm/cache.h>
39
40DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41pgd_t swapper_pg_dir[PTRS_PER_PGD];
42
43/*
44 * Cache of MMU context last used.
45 */
46unsigned long mmu_context_cache = NO_CONTEXT;
47
48#ifdef CONFIG_MMU
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)
52#endif
53
54#ifdef CONFIG_DISCONTIGMEM
55pg_data_t discontig_page_data[MAX_NUMNODES];
56bootmem_data_t discontig_node_bdata[MAX_NUMNODES];
57#endif
58
59void (*copy_page)(void *from, void *to);
60void (*clear_page)(void *to);
61
62void show_mem(void)
63{
64 int i, total = 0, reserved = 0;
65 int shared = 0, cached = 0;
66
67 printk("Mem-info:\n");
68 show_free_areas();
69 printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
70 i = max_mapnr;
71 while (i-- > 0) {
72 total++;
73 if (PageReserved(mem_map+i))
74 reserved++;
75 else if (PageSwapCache(mem_map+i))
76 cached++;
77 else if (page_count(mem_map+i))
78 shared += page_count(mem_map+i) - 1;
79 }
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);
84}
85
86static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
87{
88 pgd_t *pgd;
89 pmd_t *pmd;
90 pte_t *pte;
91
92 pgd = swapper_pg_dir + pgd_index(addr);
93 if (pgd_none(*pgd)) {
94 pgd_ERROR(*pgd);
95 return;
96 }
97
98 pmd = pmd_offset(pgd, addr);
99 if (pmd_none(*pmd)) {
100 pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
101 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
102 if (pte != pte_offset_kernel(pmd, 0)) {
103 pmd_ERROR(*pmd);
104 return;
105 }
106 }
107
108 pte = pte_offset_kernel(pmd, addr);
109 if (!pte_none(*pte)) {
110 pte_ERROR(*pte);
111 return;
112 }
113
114 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
115
116 __flush_tlb_page(get_asid(), addr);
117}
118
119/*
120 * As a performance optimization, other platforms preserve the fixmap mapping
121 * across a context switch, we don't presently do this, but this could be done
122 * in a similar fashion as to the wired TLB interface that sh64 uses (by way
123 * of the memorry mapped UTLB configuration) -- this unfortunately forces us to
124 * give up a TLB entry for each mapping we want to preserve. While this may be
125 * viable for a small number of fixmaps, it's not particularly useful for
126 * everything and needs to be carefully evaluated. (ie, we may want this for
127 * the vsyscall page).
128 *
129 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
130 * in at __set_fixmap() time to determine the appropriate behavior to follow.
131 *
132 * -- PFM.
133 */
134void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
135{
136 unsigned long address = __fix_to_virt(idx);
137
138 if (idx >= __end_of_fixed_addresses) {
139 BUG();
140 return;
141 }
142
143 set_pte_phys(address, phys, prot);
144}
145
146/* References to section boundaries */
147
148extern char _text, _etext, _edata, __bss_start, _end;
149extern char __init_begin, __init_end;
150
151/*
152 * paging_init() sets up the page tables
153 *
154 * This routines also unmaps the page at virtual kernel address 0, so
155 * that we can trap those pesky NULL-reference errors in the kernel.
156 */
157void __init paging_init(void)
158{
159 unsigned long zones_size[MAX_NR_ZONES] = { 0, };
160
161 /*
162 * Setup some defaults for the zone sizes.. these should be safe
163 * regardless of distcontiguous memory or MMU settings.
164 */
165 zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
166 zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT;
167#ifdef CONFIG_HIGHMEM
168 zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT;
169#endif
170
171#ifdef CONFIG_MMU
172 /*
173 * If we have an MMU, and want to be using it .. we need to adjust
174 * the zone sizes accordingly, in addition to turning it on.
175 */
176 {
177 unsigned long max_dma, low, start_pfn;
178 pgd_t *pg_dir;
179 int i;
180
181 /* We don't need kernel mapping as hardware support that. */
182 pg_dir = swapper_pg_dir;
183
184 for (i = 0; i < PTRS_PER_PGD; i++)
185 pgd_val(pg_dir[i]) = 0;
186
187 /* Turn on the MMU */
188 enable_mmu();
189
190 /* Fixup the zone sizes */
191 start_pfn = START_PFN;
192 max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
193 low = MAX_LOW_PFN;
194
195 if (low < max_dma) {
196 zones_size[ZONE_DMA] = low - start_pfn;
197 zones_size[ZONE_NORMAL] = 0;
198 } else {
199 zones_size[ZONE_DMA] = max_dma - start_pfn;
200 zones_size[ZONE_NORMAL] = low - max_dma;
201 }
202 }
203
204#elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
205 /*
206 * If we don't have CONFIG_MMU set and the processor in question
207 * still has an MMU, care needs to be taken to make sure it doesn't
208 * stay on.. Since the boot loader could have potentially already
209 * turned it on, and we clearly don't want it, we simply turn it off.
210 *
211 * We don't need to do anything special for the zone sizes, since the
212 * default values that were already configured up above should be
213 * satisfactory.
214 */
215 disable_mmu();
216#endif
217 NODE_DATA(0)->node_mem_map = NULL;
218 free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
219
220#ifdef CONFIG_DISCONTIGMEM
221 /*
222 * And for discontig, do some more fixups on the zone sizes..
223 */
224 zones_size[ZONE_DMA] = __MEMORY_SIZE_2ND >> PAGE_SHIFT;
225 zones_size[ZONE_NORMAL] = 0;
226 free_area_init_node(1, NODE_DATA(1), zones_size, __MEMORY_START_2ND >> PAGE_SHIFT, 0);
227#endif
228}
229
230void __init mem_init(void)
231{
232 extern unsigned long empty_zero_page[1024];
233 int codesize, reservedpages, datasize, initsize;
234 int tmp;
235 extern unsigned long memory_start;
236
237#ifdef CONFIG_MMU
238 high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
239#else
240 extern unsigned long memory_end;
241
242 high_memory = (void *)(memory_end & PAGE_MASK);
243#endif
244
245 max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start);
246
247 /* clear the zero-page */
248 memset(empty_zero_page, 0, PAGE_SIZE);
249 __flush_wback_region(empty_zero_page, PAGE_SIZE);
250
251 /*
252 * Setup wrappers for copy/clear_page(), these will get overridden
253 * later in the boot process if a better method is available.
254 */
255 copy_page = copy_page_slow;
256 clear_page = clear_page_slow;
257
258 /* this will put all low memory onto the freelists */
259 totalram_pages += free_all_bootmem_node(NODE_DATA(0));
260#ifdef CONFIG_DISCONTIGMEM
261 totalram_pages += free_all_bootmem_node(NODE_DATA(1));
262#endif
263 reservedpages = 0;
264 for (tmp = 0; tmp < num_physpages; tmp++)
265 /*
266 * Only count reserved RAM pages
267 */
268 if (PageReserved(mem_map+tmp))
269 reservedpages++;
270
271 codesize = (unsigned long) &_etext - (unsigned long) &_text;
272 datasize = (unsigned long) &_edata - (unsigned long) &_etext;
273 initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
274
275 printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n",
276 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
277 max_mapnr << (PAGE_SHIFT-10),
278 codesize >> 10,
279 reservedpages << (PAGE_SHIFT-10),
280 datasize >> 10,
281 initsize >> 10);
282
283 p3_cache_init();
284}
285
286void free_initmem(void)
287{
288 unsigned long addr;
289
290 addr = (unsigned long)(&__init_begin);
291 for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
292 ClearPageReserved(virt_to_page(addr));
293 set_page_count(virt_to_page(addr), 1);
294 free_page(addr);
295 totalram_pages++;
296 }
297 printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
298}
299
300#ifdef CONFIG_BLK_DEV_INITRD
301void free_initrd_mem(unsigned long start, unsigned long end)
302{
303 unsigned long p;
304 for (p = start; p < end; p += PAGE_SIZE) {
305 ClearPageReserved(virt_to_page(p));
306 set_page_count(virt_to_page(p), 1);
307 free_page(p);
308 totalram_pages++;
309 }
310 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
311}
312#endif
313
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