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14cf11af PM |
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> | |
7c8c6b97 PM |
48 | #include <asm/lmb.h> |
49 | #include <asm/sections.h> | |
14cf11af | 50 | |
14cf11af PM |
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 | ||
61 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); | |
62 | ||
63 | unsigned long total_memory; | |
64 | unsigned long total_lowmem; | |
65 | ||
66 | unsigned long ppc_memstart; | |
67 | unsigned long ppc_memoffset = PAGE_OFFSET; | |
68 | ||
14cf11af PM |
69 | int boot_mapsize; |
70 | #ifdef CONFIG_PPC_PMAC | |
71 | unsigned long agp_special_page; | |
72 | #endif | |
73 | ||
14cf11af PM |
74 | #ifdef CONFIG_HIGHMEM |
75 | pte_t *kmap_pte; | |
76 | pgprot_t kmap_prot; | |
77 | ||
78 | EXPORT_SYMBOL(kmap_prot); | |
79 | EXPORT_SYMBOL(kmap_pte); | |
80 | #endif | |
81 | ||
82 | void MMU_init(void); | |
14cf11af PM |
83 | |
84 | /* XXX should be in current.h -- paulus */ | |
85 | extern struct task_struct *current_set[NR_CPUS]; | |
86 | ||
87 | char *klimit = _end; | |
14cf11af PM |
88 | struct device_node *memory_node; |
89 | ||
7c8c6b97 PM |
90 | extern int init_bootmem_done; |
91 | ||
14cf11af PM |
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 | */ | |
97 | int __map_without_bats; | |
98 | int __map_without_ltlbs; | |
99 | ||
14cf11af PM |
100 | /* max amount of low RAM to map in */ |
101 | unsigned long __max_low_memory = MAX_LOW_MEM; | |
102 | ||
103 | /* | |
7c8c6b97 PM |
104 | * limit of what is accessible with initial MMU setup - |
105 | * 256MB usually, but only 16MB on 601. | |
14cf11af | 106 | */ |
7c8c6b97 | 107 | unsigned long __initial_memory_limit = 0x10000000; |
14cf11af PM |
108 | |
109 | /* | |
110 | * Check for command-line options that affect what MMU_init will do. | |
111 | */ | |
112 | void 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 | } | |
14cf11af PM |
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 | */ | |
129 | void __init MMU_init(void) | |
130 | { | |
131 | if (ppc_md.progress) | |
132 | ppc_md.progress("MMU:enter", 0x111); | |
133 | ||
7c8c6b97 PM |
134 | /* 601 can only access 16MB at the moment */ |
135 | if (PVR_VER(mfspr(SPRN_PVR)) == 1) | |
136 | __initial_memory_limit = 0x01000000; | |
137 | ||
14cf11af PM |
138 | /* parse args from command line */ |
139 | MMU_setup(); | |
140 | ||
7c8c6b97 PM |
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(); | |
14cf11af | 148 | total_lowmem = total_memory; |
7c8c6b97 | 149 | |
14cf11af PM |
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 | } | |
14cf11af PM |
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); | |
14cf11af PM |
191 | } |
192 | ||
193 | /* This is only called until mem_init is done. */ | |
194 | void __init *early_get_page(void) | |
195 | { | |
196 | void *p; | |
197 | ||
198 | if (init_bootmem_done) { | |
199 | p = alloc_bootmem_pages(PAGE_SIZE); | |
200 | } else { | |
7c8c6b97 PM |
201 | p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, |
202 | __initial_memory_limit)); | |
14cf11af PM |
203 | } |
204 | return p; | |
205 | } | |
206 | ||
207 | /* Free up now-unused memory */ | |
208 | static void free_sec(unsigned long start, unsigned long end, const char *name) | |
209 | { | |
210 | unsigned long cnt = 0; | |
211 | ||
212 | while (start < end) { | |
213 | ClearPageReserved(virt_to_page(start)); | |
214 | set_page_count(virt_to_page(start), 1); | |
215 | free_page(start); | |
216 | cnt++; | |
217 | start += PAGE_SIZE; | |
218 | } | |
219 | if (cnt) { | |
220 | printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); | |
221 | totalram_pages += cnt; | |
222 | } | |
223 | } | |
224 | ||
225 | void free_initmem(void) | |
226 | { | |
227 | #define FREESEC(TYPE) \ | |
228 | free_sec((unsigned long)(&__ ## TYPE ## _begin), \ | |
229 | (unsigned long)(&__ ## TYPE ## _end), \ | |
230 | #TYPE); | |
231 | ||
232 | printk ("Freeing unused kernel memory:"); | |
233 | FREESEC(init); | |
234 | printk("\n"); | |
235 | ppc_md.progress = NULL; | |
236 | #undef FREESEC | |
237 | } | |
238 | ||
239 | #ifdef CONFIG_BLK_DEV_INITRD | |
240 | void free_initrd_mem(unsigned long start, unsigned long end) | |
241 | { | |
242 | if (start < end) | |
243 | printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); | |
244 | for (; start < end; start += PAGE_SIZE) { | |
245 | ClearPageReserved(virt_to_page(start)); | |
246 | set_page_count(virt_to_page(start), 1); | |
247 | free_page(start); | |
248 | totalram_pages++; | |
249 | } | |
250 | } | |
251 | #endif |