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Paul Mackerras14cf11a2005-09-26 16:04:21 +10001/*
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
Paul Mackerras14cf11a2005-09-26 16:04:21 +10008 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
9 *
10 * Derived from "arch/i386/mm/init.c"
11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 *
18 */
19
Paul Mackerras14cf11a2005-09-26 16:04:21 +100020#include <linux/module.h>
21#include <linux/sched.h>
22#include <linux/kernel.h>
23#include <linux/errno.h>
24#include <linux/string.h>
25#include <linux/types.h>
26#include <linux/mm.h>
27#include <linux/stddef.h>
28#include <linux/init.h>
29#include <linux/bootmem.h>
30#include <linux/highmem.h>
31#include <linux/initrd.h>
32#include <linux/pagemap.h>
David S. Millerd9b2b2a2008-02-13 16:56:49 -080033#include <linux/lmb.h>
Paul Mackerras14cf11a2005-09-26 16:04:21 +100034
35#include <asm/pgalloc.h>
36#include <asm/prom.h>
37#include <asm/io.h>
Paul Mackerras14cf11a2005-09-26 16:04:21 +100038#include <asm/pgtable.h>
39#include <asm/mmu.h>
40#include <asm/smp.h>
41#include <asm/machdep.h>
42#include <asm/btext.h>
43#include <asm/tlb.h>
Paul Mackerras7c8c6b92005-10-06 12:23:33 +100044#include <asm/sections.h>
Michael Ellerman5f25f0652008-05-08 14:27:07 +100045#include <asm/system.h>
Paul Mackerras14cf11a2005-09-26 16:04:21 +100046
Paul Mackerras14cf11a2005-09-26 16:04:21 +100047#include "mmu_decl.h"
48
49#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
50/* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
Dale Farnsworthccdcef72008-12-17 10:09:13 +000051#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET))
Paul Mackerras14cf11a2005-09-26 16:04:21 +100052#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
53#endif
54#endif
55#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
56
Stefan Roese2bf30162008-07-10 01:09:23 +100057phys_addr_t total_memory;
58phys_addr_t total_lowmem;
Paul Mackerras14cf11a2005-09-26 16:04:21 +100059
Kumar Gala37dd2ba2008-04-22 04:22:34 +100060phys_addr_t memstart_addr = (phys_addr_t)~0ull;
61EXPORT_SYMBOL(memstart_addr);
62phys_addr_t kernstart_addr;
63EXPORT_SYMBOL(kernstart_addr);
Kumar Gala99c62dd72008-04-16 05:52:21 +100064phys_addr_t lowmem_end_addr;
Paul Mackerras14cf11a2005-09-26 16:04:21 +100065
Paul Mackerras14cf11a2005-09-26 16:04:21 +100066int boot_mapsize;
67#ifdef CONFIG_PPC_PMAC
68unsigned long agp_special_page;
Paul Mackerras5c8c56e2005-10-22 14:42:51 +100069EXPORT_SYMBOL(agp_special_page);
Paul Mackerras14cf11a2005-09-26 16:04:21 +100070#endif
71
Paul Mackerras14cf11a2005-09-26 16:04:21 +100072void MMU_init(void);
Paul Mackerras14cf11a2005-09-26 16:04:21 +100073
74/* XXX should be in current.h -- paulus */
75extern struct task_struct *current_set[NR_CPUS];
76
Paul Mackerras14cf11a2005-09-26 16:04:21 +100077/*
78 * this tells the system to map all of ram with the segregs
79 * (i.e. page tables) instead of the bats.
80 * -- Cort
81 */
82int __map_without_bats;
83int __map_without_ltlbs;
84
Paul Mackerras14cf11a2005-09-26 16:04:21 +100085/* max amount of low RAM to map in */
86unsigned long __max_low_memory = MAX_LOW_MEM;
87
88/*
Kumar Gala09b5e632008-04-16 05:52:25 +100089 * address of the limit of what is accessible with initial MMU setup -
Paul Mackerras7c8c6b92005-10-06 12:23:33 +100090 * 256MB usually, but only 16MB on 601.
Paul Mackerras14cf11a2005-09-26 16:04:21 +100091 */
Kumar Gala09b5e632008-04-16 05:52:25 +100092phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000;
Paul Mackerras14cf11a2005-09-26 16:04:21 +100093
94/*
95 * Check for command-line options that affect what MMU_init will do.
96 */
97void MMU_setup(void)
98{
99 /* Check for nobats option (used in mapin_ram). */
100 if (strstr(cmd_line, "nobats")) {
101 __map_without_bats = 1;
102 }
103
104 if (strstr(cmd_line, "noltlbs")) {
105 __map_without_ltlbs = 1;
106 }
Benjamin Herrenschmidt88df6e92007-04-12 15:30:22 +1000107#ifdef CONFIG_DEBUG_PAGEALLOC
108 __map_without_bats = 1;
109 __map_without_ltlbs = 1;
110#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000111}
112
113/*
114 * MMU_init sets up the basic memory mappings for the kernel,
115 * including both RAM and possibly some I/O regions,
116 * and sets up the page tables and the MMU hardware ready to go.
117 */
118void __init MMU_init(void)
119{
120 if (ppc_md.progress)
121 ppc_md.progress("MMU:enter", 0x111);
122
Paul Mackerras7c8c6b92005-10-06 12:23:33 +1000123 /* 601 can only access 16MB at the moment */
124 if (PVR_VER(mfspr(SPRN_PVR)) == 1)
Kumar Gala09b5e632008-04-16 05:52:25 +1000125 __initial_memory_limit_addr = 0x01000000;
John Traill544cdab2007-07-17 05:17:23 +0400126 /* 8xx can only access 8MB at the moment */
127 if (PVR_VER(mfspr(SPRN_PVR)) == 0x50)
Kumar Gala09b5e632008-04-16 05:52:25 +1000128 __initial_memory_limit_addr = 0x00800000;
Paul Mackerras7c8c6b92005-10-06 12:23:33 +1000129
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000130 /* parse args from command line */
131 MMU_setup();
132
Paul Mackerras7c8c6b92005-10-06 12:23:33 +1000133 if (lmb.memory.cnt > 1) {
134 lmb.memory.cnt = 1;
135 lmb_analyze();
136 printk(KERN_WARNING "Only using first contiguous memory region");
137 }
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000138
Kumar Gala99c62dd72008-04-16 05:52:21 +1000139 total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr;
Kumar Galad7917ba2008-04-16 05:52:22 +1000140 lowmem_end_addr = memstart_addr + total_lowmem;
Paul Mackerras7c8c6b92005-10-06 12:23:33 +1000141
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000142#ifdef CONFIG_FSL_BOOKE
143 /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
144 * entries, so we need to adjust lowmem to match the amount we can map
145 * in the fixed entries */
146 adjust_total_lowmem();
147#endif /* CONFIG_FSL_BOOKE */
Paul Mackerrasfa39dc42005-10-26 21:54:21 +1000148
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000149 if (total_lowmem > __max_low_memory) {
150 total_lowmem = __max_low_memory;
Kumar Galad7917ba2008-04-16 05:52:22 +1000151 lowmem_end_addr = memstart_addr + total_lowmem;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000152#ifndef CONFIG_HIGHMEM
153 total_memory = total_lowmem;
Kumar Galad7917ba2008-04-16 05:52:22 +1000154 lmb_enforce_memory_limit(lowmem_end_addr);
Paul Mackerrasfa39dc42005-10-26 21:54:21 +1000155 lmb_analyze();
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000156#endif /* CONFIG_HIGHMEM */
157 }
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000158
159 /* Initialize the MMU hardware */
160 if (ppc_md.progress)
161 ppc_md.progress("MMU:hw init", 0x300);
162 MMU_init_hw();
163
164 /* Map in all of RAM starting at KERNELBASE */
165 if (ppc_md.progress)
166 ppc_md.progress("MMU:mapin", 0x301);
167 mapin_ram();
168
Benjamin Herrenschmidtf637a492009-05-27 13:44:50 +1000169 /* Initialize early top-down ioremap allocator */
170 ioremap_bot = IOREMAP_TOP;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000171
172 /* Map in I/O resources */
173 if (ppc_md.progress)
174 ppc_md.progress("MMU:setio", 0x302);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000175
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000176 if (ppc_md.progress)
177 ppc_md.progress("MMU:exit", 0x211);
Benjamin Herrenschmidt51d30822005-11-23 17:57:25 +1100178
179 /* From now on, btext is no longer BAT mapped if it was at all */
180#ifdef CONFIG_BOOTX_TEXT
181 btext_unmap();
182#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000183}
184
185/* This is only called until mem_init is done. */
186void __init *early_get_page(void)
187{
188 void *p;
189
190 if (init_bootmem_done) {
191 p = alloc_bootmem_pages(PAGE_SIZE);
192 } else {
Paul Mackerras7c8c6b92005-10-06 12:23:33 +1000193 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
Kumar Gala09b5e632008-04-16 05:52:25 +1000194 __initial_memory_limit_addr));
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000195 }
196 return p;
197}
198
199/* Free up now-unused memory */
200static void free_sec(unsigned long start, unsigned long end, const char *name)
201{
202 unsigned long cnt = 0;
203
204 while (start < end) {
205 ClearPageReserved(virt_to_page(start));
Nick Piggin7835e982006-03-22 00:08:40 -0800206 init_page_count(virt_to_page(start));
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000207 free_page(start);
208 cnt++;
209 start += PAGE_SIZE;
210 }
211 if (cnt) {
212 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
213 totalram_pages += cnt;
214 }
215}
216
217void free_initmem(void)
218{
219#define FREESEC(TYPE) \
220 free_sec((unsigned long)(&__ ## TYPE ## _begin), \
221 (unsigned long)(&__ ## TYPE ## _end), \
222 #TYPE);
223
224 printk ("Freeing unused kernel memory:");
225 FREESEC(init);
226 printk("\n");
227 ppc_md.progress = NULL;
228#undef FREESEC
229}
230
231#ifdef CONFIG_BLK_DEV_INITRD
232void free_initrd_mem(unsigned long start, unsigned long end)
233{
234 if (start < end)
235 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
236 for (; start < end; start += PAGE_SIZE) {
237 ClearPageReserved(virt_to_page(start));
Nick Piggin7835e982006-03-22 00:08:40 -0800238 init_page_count(virt_to_page(start));
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000239 free_page(start);
240 totalram_pages++;
241 }
242}
243#endif
Ed Swarthoutdf174e32007-09-21 12:53:02 +1000244