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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 | ||
14cf11af PM |
21 | #include <linux/module.h> |
22 | #include <linux/sched.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/errno.h> | |
25 | #include <linux/string.h> | |
26 | #include <linux/types.h> | |
27 | #include <linux/mm.h> | |
28 | #include <linux/stddef.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/bootmem.h> | |
31 | #include <linux/highmem.h> | |
32 | #include <linux/initrd.h> | |
33 | #include <linux/pagemap.h> | |
34 | ||
35 | #include <asm/pgalloc.h> | |
36 | #include <asm/prom.h> | |
37 | #include <asm/io.h> | |
38 | #include <asm/mmu_context.h> | |
39 | #include <asm/pgtable.h> | |
40 | #include <asm/mmu.h> | |
41 | #include <asm/smp.h> | |
42 | #include <asm/machdep.h> | |
43 | #include <asm/btext.h> | |
44 | #include <asm/tlb.h> | |
14cf11af | 45 | #include <asm/prom.h> |
7c8c6b97 PM |
46 | #include <asm/lmb.h> |
47 | #include <asm/sections.h> | |
14cf11af | 48 | |
14cf11af PM |
49 | #include "mmu_decl.h" |
50 | ||
51 | #if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL) | |
52 | /* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */ | |
53 | #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE)) | |
54 | #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL" | |
55 | #endif | |
56 | #endif | |
57 | #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE | |
58 | ||
59 | DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); | |
60 | ||
61 | unsigned long total_memory; | |
62 | unsigned long total_lowmem; | |
63 | ||
64 | unsigned long ppc_memstart; | |
65 | unsigned long ppc_memoffset = PAGE_OFFSET; | |
66 | ||
14cf11af PM |
67 | int boot_mapsize; |
68 | #ifdef CONFIG_PPC_PMAC | |
69 | unsigned long agp_special_page; | |
5c8c56eb | 70 | EXPORT_SYMBOL(agp_special_page); |
14cf11af PM |
71 | #endif |
72 | ||
14cf11af PM |
73 | #ifdef CONFIG_HIGHMEM |
74 | pte_t *kmap_pte; | |
75 | pgprot_t kmap_prot; | |
76 | ||
77 | EXPORT_SYMBOL(kmap_prot); | |
78 | EXPORT_SYMBOL(kmap_pte); | |
79 | #endif | |
80 | ||
81 | void MMU_init(void); | |
14cf11af PM |
82 | |
83 | /* XXX should be in current.h -- paulus */ | |
84 | extern struct task_struct *current_set[NR_CPUS]; | |
85 | ||
7c8c6b97 PM |
86 | extern int init_bootmem_done; |
87 | ||
14cf11af PM |
88 | /* |
89 | * this tells the system to map all of ram with the segregs | |
90 | * (i.e. page tables) instead of the bats. | |
91 | * -- Cort | |
92 | */ | |
93 | int __map_without_bats; | |
94 | int __map_without_ltlbs; | |
95 | ||
14cf11af PM |
96 | /* max amount of low RAM to map in */ |
97 | unsigned long __max_low_memory = MAX_LOW_MEM; | |
98 | ||
99 | /* | |
7c8c6b97 PM |
100 | * limit of what is accessible with initial MMU setup - |
101 | * 256MB usually, but only 16MB on 601. | |
14cf11af | 102 | */ |
7c8c6b97 | 103 | unsigned long __initial_memory_limit = 0x10000000; |
14cf11af PM |
104 | |
105 | /* | |
106 | * Check for command-line options that affect what MMU_init will do. | |
107 | */ | |
108 | void MMU_setup(void) | |
109 | { | |
110 | /* Check for nobats option (used in mapin_ram). */ | |
111 | if (strstr(cmd_line, "nobats")) { | |
112 | __map_without_bats = 1; | |
113 | } | |
114 | ||
115 | if (strstr(cmd_line, "noltlbs")) { | |
116 | __map_without_ltlbs = 1; | |
117 | } | |
88df6e90 BH |
118 | #ifdef CONFIG_DEBUG_PAGEALLOC |
119 | __map_without_bats = 1; | |
120 | __map_without_ltlbs = 1; | |
121 | #endif | |
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 */ | |
fa39dc43 | 156 | |
14cf11af PM |
157 | if (total_lowmem > __max_low_memory) { |
158 | total_lowmem = __max_low_memory; | |
159 | #ifndef CONFIG_HIGHMEM | |
160 | total_memory = total_lowmem; | |
fa39dc43 PM |
161 | lmb_enforce_memory_limit(total_lowmem); |
162 | lmb_analyze(); | |
14cf11af PM |
163 | #endif /* CONFIG_HIGHMEM */ |
164 | } | |
14cf11af PM |
165 | |
166 | /* Initialize the MMU hardware */ | |
167 | if (ppc_md.progress) | |
168 | ppc_md.progress("MMU:hw init", 0x300); | |
169 | MMU_init_hw(); | |
170 | ||
171 | /* Map in all of RAM starting at KERNELBASE */ | |
172 | if (ppc_md.progress) | |
173 | ppc_md.progress("MMU:mapin", 0x301); | |
174 | mapin_ram(); | |
175 | ||
176 | #ifdef CONFIG_HIGHMEM | |
177 | ioremap_base = PKMAP_BASE; | |
178 | #else | |
179 | ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */ | |
180 | #endif /* CONFIG_HIGHMEM */ | |
181 | ioremap_bot = ioremap_base; | |
182 | ||
183 | /* Map in I/O resources */ | |
184 | if (ppc_md.progress) | |
185 | ppc_md.progress("MMU:setio", 0x302); | |
186 | if (ppc_md.setup_io_mappings) | |
187 | ppc_md.setup_io_mappings(); | |
188 | ||
189 | /* Initialize the context management stuff */ | |
190 | mmu_context_init(); | |
191 | ||
192 | if (ppc_md.progress) | |
193 | ppc_md.progress("MMU:exit", 0x211); | |
51d3082f BH |
194 | |
195 | /* From now on, btext is no longer BAT mapped if it was at all */ | |
196 | #ifdef CONFIG_BOOTX_TEXT | |
197 | btext_unmap(); | |
198 | #endif | |
14cf11af PM |
199 | } |
200 | ||
201 | /* This is only called until mem_init is done. */ | |
202 | void __init *early_get_page(void) | |
203 | { | |
204 | void *p; | |
205 | ||
206 | if (init_bootmem_done) { | |
207 | p = alloc_bootmem_pages(PAGE_SIZE); | |
208 | } else { | |
7c8c6b97 PM |
209 | p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE, |
210 | __initial_memory_limit)); | |
14cf11af PM |
211 | } |
212 | return p; | |
213 | } | |
214 | ||
215 | /* Free up now-unused memory */ | |
216 | static void free_sec(unsigned long start, unsigned long end, const char *name) | |
217 | { | |
218 | unsigned long cnt = 0; | |
219 | ||
220 | while (start < end) { | |
221 | ClearPageReserved(virt_to_page(start)); | |
7835e98b | 222 | init_page_count(virt_to_page(start)); |
14cf11af PM |
223 | free_page(start); |
224 | cnt++; | |
225 | start += PAGE_SIZE; | |
226 | } | |
227 | if (cnt) { | |
228 | printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name); | |
229 | totalram_pages += cnt; | |
230 | } | |
231 | } | |
232 | ||
233 | void free_initmem(void) | |
234 | { | |
235 | #define FREESEC(TYPE) \ | |
236 | free_sec((unsigned long)(&__ ## TYPE ## _begin), \ | |
237 | (unsigned long)(&__ ## TYPE ## _end), \ | |
238 | #TYPE); | |
239 | ||
240 | printk ("Freeing unused kernel memory:"); | |
241 | FREESEC(init); | |
242 | printk("\n"); | |
243 | ppc_md.progress = NULL; | |
244 | #undef FREESEC | |
245 | } | |
246 | ||
247 | #ifdef CONFIG_BLK_DEV_INITRD | |
248 | void free_initrd_mem(unsigned long start, unsigned long end) | |
249 | { | |
250 | if (start < end) | |
251 | printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10); | |
252 | for (; start < end; start += PAGE_SIZE) { | |
253 | ClearPageReserved(virt_to_page(start)); | |
7835e98b | 254 | init_page_count(virt_to_page(start)); |
14cf11af PM |
255 | free_page(start); |
256 | totalram_pages++; | |
257 | } | |
258 | } | |
259 | #endif |