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/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>
  45 #include <asm/sections.h>
  46 #include <asm/system.h>
  47
  48 #include "mmu_decl.h"
  49
  50 #if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
  51 /* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
  52 #if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
  53 #error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
  54 #endif
  55 #endif
  56 #define MAX_LOW_MEM     CONFIG_LOWMEM_SIZE
  57
  58 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  59
  60 phys_addr_t total_memory;
  61 phys_addr_t total_lowmem;
  62
  63 phys_addr_t memstart_addr = (phys_addr_t)~0ull;
  64 EXPORT_SYMBOL(memstart_addr);
  65 phys_addr_t kernstart_addr;
  66 EXPORT_SYMBOL(kernstart_addr);
  67 phys_addr_t lowmem_end_addr;
  68
  69 int boot_mapsize;
  70 #ifdef CONFIG_PPC_PMAC
  71 unsigned long agp_special_page;
  72 EXPORT_SYMBOL(agp_special_page);
  73 #endif
  74
  75 void MMU_init(void);
  76
  77 /* XXX should be in current.h  -- paulus */
  78 extern struct task_struct *current_set[NR_CPUS];
  79
  80 /*
  81  * this tells the system to map all of ram with the segregs
  82  * (i.e. page tables) instead of the bats.
  83  * -- Cort
  84  */
  85 int __map_without_bats;
  86 int __map_without_ltlbs;
  87
  88 /* max amount of low RAM to map in */
  89 unsigned long __max_low_memory = MAX_LOW_MEM;
  90
  91 /*
  92  * address of the limit of what is accessible with initial MMU setup -
  93  * 256MB usually, but only 16MB on 601.
  94  */
  95 phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000;
  96
  97 /*
  98  * Check for command-line options that affect what MMU_init will do.
  99  */
 100 void MMU_setup(void)
 101 {
 102         /* Check for nobats option (used in mapin_ram). */
 103         if (strstr(cmd_line, "nobats")) {
 104                 __map_without_bats = 1;
 105         }
 106
 107         if (strstr(cmd_line, "noltlbs")) {
 108                 __map_without_ltlbs = 1;
 109         }
 110 #ifdef CONFIG_DEBUG_PAGEALLOC
 111         __map_without_bats = 1;
 112         __map_without_ltlbs = 1;
 113 #endif
 114 }
 115
 116 /*
 117  * MMU_init sets up the basic memory mappings for the kernel,
 118  * including both RAM and possibly some I/O regions,
 119  * and sets up the page tables and the MMU hardware ready to go.
 120  */
 121 void __init MMU_init(void)
 122 {
 123         if (ppc_md.progress)
 124                 ppc_md.progress("MMU:enter", 0x111);
 125
 126         /* 601 can only access 16MB at the moment */
 127         if (PVR_VER(mfspr(SPRN_PVR)) == 1)
 128                 __initial_memory_limit_addr = 0x01000000;
 129         /* 8xx can only access 8MB at the moment */
 130         if (PVR_VER(mfspr(SPRN_PVR)) == 0x50)
 131                 __initial_memory_limit_addr = 0x00800000;
 132
 133         /* parse args from command line */
 134         MMU_setup();
 135
 136         if (lmb.memory.cnt > 1) {
 137                 lmb.memory.cnt = 1;
 138                 lmb_analyze();
 139                 printk(KERN_WARNING "Only using first contiguous memory region");
 140         }
 141
 142         total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr;
 143         lowmem_end_addr = memstart_addr + total_lowmem;
 144
 145 #ifdef CONFIG_FSL_BOOKE
 146         /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
 147          * entries, so we need to adjust lowmem to match the amount we can map
 148          * in the fixed entries */
 149         adjust_total_lowmem();
 150 #endif /* CONFIG_FSL_BOOKE */
 151
 152         if (total_lowmem > __max_low_memory) {
 153                 total_lowmem = __max_low_memory;
 154                 lowmem_end_addr = memstart_addr + total_lowmem;
 155 #ifndef CONFIG_HIGHMEM
 156                 total_memory = total_lowmem;
 157                 lmb_enforce_memory_limit(lowmem_end_addr);
 158                 lmb_analyze();
 159 #endif /* CONFIG_HIGHMEM */
 160         }
 161
 162         /* Initialize the MMU hardware */
 163         if (ppc_md.progress)
 164                 ppc_md.progress("MMU:hw init", 0x300);
 165         MMU_init_hw();
 166
 167         /* Map in all of RAM starting at KERNELBASE */
 168         if (ppc_md.progress)
 169                 ppc_md.progress("MMU:mapin", 0x301);
 170         mapin_ram();
 171
 172 #ifdef CONFIG_HIGHMEM
 173         ioremap_base = PKMAP_BASE;
 174 #else
 175         ioremap_base = 0xfe000000UL;    /* for now, could be 0xfffff000 */
 176 #endif /* CONFIG_HIGHMEM */
 177         ioremap_bot = ioremap_base;
 178
 179         /* Map in I/O resources */
 180         if (ppc_md.progress)
 181                 ppc_md.progress("MMU:setio", 0x302);
 182
 183         /* Initialize the context management stuff */
 184         mmu_context_init();
 185
 186         if (ppc_md.progress)
 187                 ppc_md.progress("MMU:exit", 0x211);
 188
 189         /* From now on, btext is no longer BAT mapped if it was at all */
 190 #ifdef CONFIG_BOOTX_TEXT
 191         btext_unmap();
 192 #endif
 193 }
 194
 195 /* This is only called until mem_init is done. */
 196 void __init *early_get_page(void)
 197 {
 198         void *p;
 199
 200         if (init_bootmem_done) {
 201                 p = alloc_bootmem_pages(PAGE_SIZE);
 202         } else {
 203                 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
 204                                         __initial_memory_limit_addr));
 205         }
 206         return p;
 207 }
 208
 209 /* Free up now-unused memory */
 210 static void free_sec(unsigned long start, unsigned long end, const char *name)
 211 {
 212         unsigned long cnt = 0;
 213
 214         while (start < end) {
 215                 ClearPageReserved(virt_to_page(start));
 216                 init_page_count(virt_to_page(start));
 217                 free_page(start);
 218                 cnt++;
 219                 start += PAGE_SIZE;
 220         }
 221         if (cnt) {
 222                 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
 223                 totalram_pages += cnt;
 224         }
 225 }
 226
 227 void free_initmem(void)
 228 {
 229 #define FREESEC(TYPE) \
 230         free_sec((unsigned long)(&__ ## TYPE ## _begin), \
 231                  (unsigned long)(&__ ## TYPE ## _end), \
 232                  #TYPE);
 233
 234         printk ("Freeing unused kernel memory:");
 235         FREESEC(init);
 236         printk("\n");
 237         ppc_md.progress = NULL;
 238 #undef FREESEC
 239 }
 240
 241 #ifdef CONFIG_BLK_DEV_INITRD
 242 void free_initrd_mem(unsigned long start, unsigned long end)
 243 {
 244         if (start < end)
 245                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 246         for (; start < end; start += PAGE_SIZE) {
 247                 ClearPageReserved(virt_to_page(start));
 248                 init_page_count(virt_to_page(start));
 249                 free_page(start);
 250                 totalram_pages++;
 251         }
 252 }
 253 #endif
 254
 255 #ifdef CONFIG_PROC_KCORE
 256 static struct kcore_list kcore_vmem;
 257
 258 static int __init setup_kcore(void)
 259 {
 260         int i;
 261
 262         for (i = 0; i < lmb.memory.cnt; i++) {
 263                 unsigned long base;
 264                 unsigned long size;
 265                 struct kcore_list *kcore_mem;
 266
 267                 base = lmb.memory.region[i].base;
 268                 size = lmb.memory.region[i].size;
 269
 270                 kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC);
 271                 if (!kcore_mem)
 272                         panic("%s: kmalloc failed\n", __func__);
 273
 274                 /* must stay under 32 bits */
 275                 if ( 0xfffffffful - (unsigned long)__va(base) < size) {
 276                         size = 0xfffffffful - (unsigned long)(__va(base));
 277                         printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n",
 278                                                 size);
 279                 }
 280
 281                 kclist_add(kcore_mem, __va(base), size);
 282         }
 283
 284         kclist_add(&kcore_vmem, (void *)VMALLOC_START,
 285                 VMALLOC_END-VMALLOC_START);
 286
 287         return 0;
 288 }
 289 module_init(setup_kcore);
 290 #endif