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-rw-r--r--arch/powerpc/mm/init_32.c258
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diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
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1/*
2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
6 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
7 * Copyright (C) 1996 Paul Mackerras
8 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
9 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
10 *
11 * Derived from "arch/i386/mm/init.c"
12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21#include <linux/config.h>
22#include <linux/module.h>
23#include <linux/sched.h>
24#include <linux/kernel.h>
25#include <linux/errno.h>
26#include <linux/string.h>
27#include <linux/types.h>
28#include <linux/mm.h>
29#include <linux/stddef.h>
30#include <linux/init.h>
31#include <linux/bootmem.h>
32#include <linux/highmem.h>
33#include <linux/initrd.h>
34#include <linux/pagemap.h>
35
36#include <asm/pgalloc.h>
37#include <asm/prom.h>
38#include <asm/io.h>
39#include <asm/mmu_context.h>
40#include <asm/pgtable.h>
41#include <asm/mmu.h>
42#include <asm/smp.h>
43#include <asm/machdep.h>
44#include <asm/btext.h>
45#include <asm/tlb.h>
46#include <asm/bootinfo.h>
47#include <asm/prom.h>
48#include <asm/lmb.h>
49#include <asm/sections.h>
50
51#include "mmu_decl.h"
52
53#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
54/* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
55#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
56#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
57#endif
58#endif
59#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
60
61DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
62
63unsigned long total_memory;
64unsigned long total_lowmem;
65
66unsigned long ppc_memstart;
67unsigned long ppc_memoffset = PAGE_OFFSET;
68
69int boot_mapsize;
70#ifdef CONFIG_PPC_PMAC
71unsigned long agp_special_page;
72#endif
73
74#ifdef CONFIG_HIGHMEM
75pte_t *kmap_pte;
76pgprot_t kmap_prot;
77
78EXPORT_SYMBOL(kmap_prot);
79EXPORT_SYMBOL(kmap_pte);
80#endif
81
82void MMU_init(void);
83
84/* XXX should be in current.h -- paulus */
85extern struct task_struct *current_set[NR_CPUS];
86
87char *klimit = _end;
88struct device_node *memory_node;
89
90extern int init_bootmem_done;
91
92/*
93 * this tells the system to map all of ram with the segregs
94 * (i.e. page tables) instead of the bats.
95 * -- Cort
96 */
97int __map_without_bats;
98int __map_without_ltlbs;
99
100/* max amount of low RAM to map in */
101unsigned long __max_low_memory = MAX_LOW_MEM;
102
103/*
104 * limit of what is accessible with initial MMU setup -
105 * 256MB usually, but only 16MB on 601.
106 */
107unsigned long __initial_memory_limit = 0x10000000;
108
109/*
110 * Check for command-line options that affect what MMU_init will do.
111 */
112void MMU_setup(void)
113{
114 /* Check for nobats option (used in mapin_ram). */
115 if (strstr(cmd_line, "nobats")) {
116 __map_without_bats = 1;
117 }
118
119 if (strstr(cmd_line, "noltlbs")) {
120 __map_without_ltlbs = 1;
121 }
122}
123
124/*
125 * MMU_init sets up the basic memory mappings for the kernel,
126 * including both RAM and possibly some I/O regions,
127 * and sets up the page tables and the MMU hardware ready to go.
128 */
129void __init MMU_init(void)
130{
131 if (ppc_md.progress)
132 ppc_md.progress("MMU:enter", 0x111);
133
134 /* 601 can only access 16MB at the moment */
135 if (PVR_VER(mfspr(SPRN_PVR)) == 1)
136 __initial_memory_limit = 0x01000000;
137
138 /* parse args from command line */
139 MMU_setup();
140
141 if (lmb.memory.cnt > 1) {
142 lmb.memory.cnt = 1;
143 lmb_analyze();
144 printk(KERN_WARNING "Only using first contiguous memory region");
145 }
146
147 total_memory = lmb_end_of_DRAM();
148 total_lowmem = total_memory;
149
150#ifdef CONFIG_FSL_BOOKE
151 /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
152 * entries, so we need to adjust lowmem to match the amount we can map
153 * in the fixed entries */
154 adjust_total_lowmem();
155#endif /* CONFIG_FSL_BOOKE */
156 if (total_lowmem > __max_low_memory) {
157 total_lowmem = __max_low_memory;
158#ifndef CONFIG_HIGHMEM
159 total_memory = total_lowmem;
160#endif /* CONFIG_HIGHMEM */
161 }
162
163 /* Initialize the MMU hardware */
164 if (ppc_md.progress)
165 ppc_md.progress("MMU:hw init", 0x300);
166 MMU_init_hw();
167
168 /* Map in all of RAM starting at KERNELBASE */
169 if (ppc_md.progress)
170 ppc_md.progress("MMU:mapin", 0x301);
171 mapin_ram();
172
173#ifdef CONFIG_HIGHMEM
174 ioremap_base = PKMAP_BASE;
175#else
176 ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
177#endif /* CONFIG_HIGHMEM */
178 ioremap_bot = ioremap_base;
179
180 /* Map in I/O resources */
181 if (ppc_md.progress)
182 ppc_md.progress("MMU:setio", 0x302);
183 if (ppc_md.setup_io_mappings)
184 ppc_md.setup_io_mappings();
185
186 /* Initialize the context management stuff */
187 mmu_context_init();
188
189 if (ppc_md.progress)
190 ppc_md.progress("MMU:exit", 0x211);
191
192#ifdef CONFIG_BOOTX_TEXT
193 /* By default, we are no longer mapped */
194 boot_text_mapped = 0;
195 /* Must be done last, or ppc_md.progress will die. */
196 map_boot_text();
197#endif
198}
199
200/* This is only called until mem_init is done. */
201void __init *early_get_page(void)
202{
203 void *p;
204
205 if (init_bootmem_done) {
206 p = alloc_bootmem_pages(PAGE_SIZE);
207 } else {
208 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
209 __initial_memory_limit));
210 }
211 return p;
212}
213
214/* Free up now-unused memory */
215static void free_sec(unsigned long start, unsigned long end, const char *name)
216{
217 unsigned long cnt = 0;
218
219 while (start < end) {
220 ClearPageReserved(virt_to_page(start));
221 set_page_count(virt_to_page(start), 1);
222 free_page(start);
223 cnt++;
224 start += PAGE_SIZE;
225 }
226 if (cnt) {
227 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
228 totalram_pages += cnt;
229 }
230}
231
232void free_initmem(void)
233{
234#define FREESEC(TYPE) \
235 free_sec((unsigned long)(&__ ## TYPE ## _begin), \
236 (unsigned long)(&__ ## TYPE ## _end), \
237 #TYPE);
238
239 printk ("Freeing unused kernel memory:");
240 FREESEC(init);
241 printk("\n");
242 ppc_md.progress = NULL;
243#undef FREESEC
244}
245
246#ifdef CONFIG_BLK_DEV_INITRD
247void free_initrd_mem(unsigned long start, unsigned long end)
248{
249 if (start < end)
250 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
251 for (; start < end; start += PAGE_SIZE) {
252 ClearPageReserved(virt_to_page(start));
253 set_page_count(virt_to_page(start), 1);
254 free_page(start);
255 totalram_pages++;
256 }
257}
258#endif