arch/powerpc/mm/init_32.c

   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  *  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
  20 #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>
  33 #include <linux/lmb.h>
  34
  35 #include <asm/pgalloc.h>
  36 #include <asm/prom.h>
  37 #include <asm/io.h>
  38 #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>
  44 #include <asm/sections.h>
  45 #include <asm/system.h>
  46
  47 #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. */
  51 #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - PAGE_OFFSET))
  52 #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
  53 #endif
  54 #endif
  55 #define MAX_LOW_MEM     CONFIG_LOWMEM_SIZE
  56
  57 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  58
  59 phys_addr_t total_memory;
  60 phys_addr_t total_lowmem;
  61
  62 phys_addr_t memstart_addr = (phys_addr_t)~0ull;
  63 EXPORT_SYMBOL(memstart_addr);
  64 phys_addr_t kernstart_addr;
  65 EXPORT_SYMBOL(kernstart_addr);
  66 phys_addr_t lowmem_end_addr;
  67
  68 int boot_mapsize;
  69 #ifdef CONFIG_PPC_PMAC
  70 unsigned long agp_special_page;
  71 EXPORT_SYMBOL(agp_special_page);
  72 #endif
  73
  74 void MMU_init(void);
  75
  76 /* XXX should be in current.h  -- paulus */
  77 extern struct task_struct *current_set[NR_CPUS];
  78
  79 /*
  80  * this tells the system to map all of ram with the segregs
  81  * (i.e. page tables) instead of the bats.
  82  * -- Cort
  83  */
  84 int __map_without_bats;
  85 int __map_without_ltlbs;
  86
  87 /* max amount of low RAM to map in */
  88 unsigned long __max_low_memory = MAX_LOW_MEM;
  89
  90 /*
  91  * address of the limit of what is accessible with initial MMU setup -
  92  * 256MB usually, but only 16MB on 601.
  93  */
  94 phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000;
  95
  96 /*
  97  * Check for command-line options that affect what MMU_init will do.
  98  */
  99 void MMU_setup(void)
 100 {
 101         /* Check for nobats option (used in mapin_ram). */
 102         if (strstr(cmd_line, "nobats")) {
 103                 __map_without_bats = 1;
 104         }
 105
 106         if (strstr(cmd_line, "noltlbs")) {
 107                 __map_without_ltlbs = 1;
 108         }
 109 #ifdef CONFIG_DEBUG_PAGEALLOC
 110         __map_without_bats = 1;
 111         __map_without_ltlbs = 1;
 112 #endif
 113 }
 114
 115 /*
 116  * MMU_init sets up the basic memory mappings for the kernel,
 117  * including both RAM and possibly some I/O regions,
 118  * and sets up the page tables and the MMU hardware ready to go.
 119  */
 120 void __init MMU_init(void)
 121 {
 122         if (ppc_md.progress)
 123                 ppc_md.progress("MMU:enter", 0x111);
 124
 125         /* 601 can only access 16MB at the moment */
 126         if (PVR_VER(mfspr(SPRN_PVR)) == 1)
 127                 __initial_memory_limit_addr = 0x01000000;
 128         /* 8xx can only access 8MB at the moment */
 129         if (PVR_VER(mfspr(SPRN_PVR)) == 0x50)
 130                 __initial_memory_limit_addr = 0x00800000;
 131
 132         /* parse args from command line */
 133         MMU_setup();
 134
 135         if (lmb.memory.cnt > 1) {
 136                 lmb.memory.cnt = 1;
 137                 lmb_analyze();
 138                 printk(KERN_WARNING "Only using first contiguous memory region");
 139         }
 140
 141         total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr;
 142         lowmem_end_addr = memstart_addr + total_lowmem;
 143
 144 #ifdef CONFIG_FSL_BOOKE
 145         /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
 146          * entries, so we need to adjust lowmem to match the amount we can map
 147          * in the fixed entries */
 148         adjust_total_lowmem();
 149 #endif /* CONFIG_FSL_BOOKE */
 150
 151         if (total_lowmem > __max_low_memory) {
 152                 total_lowmem = __max_low_memory;
 153                 lowmem_end_addr = memstart_addr + total_lowmem;
 154 #ifndef CONFIG_HIGHMEM
 155                 total_memory = total_lowmem;
 156                 lmb_enforce_memory_limit(lowmem_end_addr);
 157                 lmb_analyze();
 158 #endif /* CONFIG_HIGHMEM */
 159         }
 160
 161         /* Initialize the MMU hardware */
 162         if (ppc_md.progress)
 163                 ppc_md.progress("MMU:hw init", 0x300);
 164         MMU_init_hw();
 165
 166         /* Map in all of RAM starting at KERNELBASE */
 167         if (ppc_md.progress)
 168                 ppc_md.progress("MMU:mapin", 0x301);
 169         mapin_ram();
 170
 171         /* Initialize early top-down ioremap allocator */
 172         ioremap_bot = IOREMAP_TOP;
 173
 174         /* Map in I/O resources */
 175         if (ppc_md.progress)
 176                 ppc_md.progress("MMU:setio", 0x302);
 177
 178         if (ppc_md.progress)
 179                 ppc_md.progress("MMU:exit", 0x211);
 180
 181         /* From now on, btext is no longer BAT mapped if it was at all */
 182 #ifdef CONFIG_BOOTX_TEXT
 183         btext_unmap();
 184 #endif
 185 }
 186
 187 /* This is only called until mem_init is done. */
 188 void __init *early_get_page(void)
 189 {
 190         void *p;
 191
 192         if (init_bootmem_done) {
 193                 p = alloc_bootmem_pages(PAGE_SIZE);
 194         } else {
 195                 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
 196                                         __initial_memory_limit_addr));
 197         }
 198         return p;
 199 }
 200
 201 /* Free up now-unused memory */
 202 static void free_sec(unsigned long start, unsigned long end, const char *name)
 203 {
 204         unsigned long cnt = 0;
 205
 206         while (start < end) {
 207                 ClearPageReserved(virt_to_page(start));
 208                 init_page_count(virt_to_page(start));
 209                 free_page(start);
 210                 cnt++;
 211                 start += PAGE_SIZE;
 212         }
 213         if (cnt) {
 214                 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
 215                 totalram_pages += cnt;
 216         }
 217 }
 218
 219 void free_initmem(void)
 220 {
 221 #define FREESEC(TYPE) \
 222         free_sec((unsigned long)(&__ ## TYPE ## _begin), \
 223                  (unsigned long)(&__ ## TYPE ## _end), \
 224                  #TYPE);
 225
 226         printk ("Freeing unused kernel memory:");
 227         FREESEC(init);
 228         printk("\n");
 229         ppc_md.progress = NULL;
 230 #undef FREESEC
 231 }
 232
 233 #ifdef CONFIG_BLK_DEV_INITRD
 234 void free_initrd_mem(unsigned long start, unsigned long end)
 235 {
 236         if (start < end)
 237                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 238         for (; start < end; start += PAGE_SIZE) {
 239                 ClearPageReserved(virt_to_page(start));
 240                 init_page_count(virt_to_page(start));
 241                 free_page(start);
 242                 totalram_pages++;
 243         }
 244 }
 245 #endif
 246
 247 #ifdef CONFIG_PROC_KCORE
 248 static struct kcore_list kcore_vmem;
 249
 250 static int __init setup_kcore(void)
 251 {
 252         int i;
 253
 254         for (i = 0; i < lmb.memory.cnt; i++) {
 255                 unsigned long base;
 256                 unsigned long size;
 257                 struct kcore_list *kcore_mem;
 258
 259                 base = lmb.memory.region[i].base;
 260                 size = lmb.memory.region[i].size;
 261
 262                 kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC);
 263                 if (!kcore_mem)
 264                         panic("%s: kmalloc failed\n", __func__);
 265
 266                 /* must stay under 32 bits */
 267                 if ( 0xfffffffful - (unsigned long)__va(base) < size) {
 268                         size = 0xfffffffful - (unsigned long)(__va(base));
 269                         printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n",
 270                                                 size);
 271                 }
 272
 273                 kclist_add(kcore_mem, __va(base), size);
 274         }
 275
 276         kclist_add(&kcore_vmem, (void *)VMALLOC_START,
 277                 VMALLOC_END-VMALLOC_START);
 278
 279         return 0;
 280 }
 281 module_init(setup_kcore);
 282 #endif