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
  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 - KERNELBASE))
  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 unsigned long total_memory;
  60 unsigned long 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 #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);
  83
  84 /* XXX should be in current.h  -- paulus */
  85 extern struct task_struct *current_set[NR_CPUS];
  86
  87 extern int init_bootmem_done;
  88
  89 /*
  90  * this tells the system to map all of ram with the segregs
  91  * (i.e. page tables) instead of the bats.
  92  * -- Cort
  93  */
  94 int __map_without_bats;
  95 int __map_without_ltlbs;
  96
  97 /* max amount of low RAM to map in */
  98 unsigned long __max_low_memory = MAX_LOW_MEM;
  99
 100 /*
 101  * address of the limit of what is accessible with initial MMU setup -
 102  * 256MB usually, but only 16MB on 601.
 103  */
 104 phys_addr_t __initial_memory_limit_addr = (phys_addr_t)0x10000000;
 105
 106 /*
 107  * Check for command-line options that affect what MMU_init will do.
 108  */
 109 void MMU_setup(void)
 110 {
 111         /* Check for nobats option (used in mapin_ram). */
 112         if (strstr(cmd_line, "nobats")) {
 113                 __map_without_bats = 1;
 114         }
 115
 116         if (strstr(cmd_line, "noltlbs")) {
 117                 __map_without_ltlbs = 1;
 118         }
 119 #ifdef CONFIG_DEBUG_PAGEALLOC
 120         __map_without_bats = 1;
 121         __map_without_ltlbs = 1;
 122 #endif
 123 }
 124
 125 /*
 126  * MMU_init sets up the basic memory mappings for the kernel,
 127  * including both RAM and possibly some I/O regions,
 128  * and sets up the page tables and the MMU hardware ready to go.
 129  */
 130 void __init MMU_init(void)
 131 {
 132         if (ppc_md.progress)
 133                 ppc_md.progress("MMU:enter", 0x111);
 134
 135         /* 601 can only access 16MB at the moment */
 136         if (PVR_VER(mfspr(SPRN_PVR)) == 1)
 137                 __initial_memory_limit_addr = 0x01000000;
 138         /* 8xx can only access 8MB at the moment */
 139         if (PVR_VER(mfspr(SPRN_PVR)) == 0x50)
 140                 __initial_memory_limit_addr = 0x00800000;
 141
 142         /* parse args from command line */
 143         MMU_setup();
 144
 145         if (lmb.memory.cnt > 1) {
 146                 lmb.memory.cnt = 1;
 147                 lmb_analyze();
 148                 printk(KERN_WARNING "Only using first contiguous memory region");
 149         }
 150
 151         total_lowmem = total_memory = lmb_end_of_DRAM() - memstart_addr;
 152         lowmem_end_addr = memstart_addr + total_lowmem;
 153
 154 #ifdef CONFIG_FSL_BOOKE
 155         /* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
 156          * entries, so we need to adjust lowmem to match the amount we can map
 157          * in the fixed entries */
 158         adjust_total_lowmem();
 159 #endif /* CONFIG_FSL_BOOKE */
 160
 161         if (total_lowmem > __max_low_memory) {
 162                 total_lowmem = __max_low_memory;
 163                 lowmem_end_addr = memstart_addr + total_lowmem;
 164 #ifndef CONFIG_HIGHMEM
 165                 total_memory = total_lowmem;
 166                 lmb_enforce_memory_limit(lowmem_end_addr);
 167                 lmb_analyze();
 168 #endif /* CONFIG_HIGHMEM */
 169         }
 170
 171         /* Initialize the MMU hardware */
 172         if (ppc_md.progress)
 173                 ppc_md.progress("MMU:hw init", 0x300);
 174         MMU_init_hw();
 175
 176         /* Map in all of RAM starting at KERNELBASE */
 177         if (ppc_md.progress)
 178                 ppc_md.progress("MMU:mapin", 0x301);
 179         mapin_ram();
 180
 181 #ifdef CONFIG_HIGHMEM
 182         ioremap_base = PKMAP_BASE;
 183 #else
 184         ioremap_base = 0xfe000000UL;    /* for now, could be 0xfffff000 */
 185 #endif /* CONFIG_HIGHMEM */
 186         ioremap_bot = ioremap_base;
 187
 188         /* Map in I/O resources */
 189         if (ppc_md.progress)
 190                 ppc_md.progress("MMU:setio", 0x302);
 191
 192         /* Initialize the context management stuff */
 193         mmu_context_init();
 194
 195         if (ppc_md.progress)
 196                 ppc_md.progress("MMU:exit", 0x211);
 197
 198         /* From now on, btext is no longer BAT mapped if it was at all */
 199 #ifdef CONFIG_BOOTX_TEXT
 200         btext_unmap();
 201 #endif
 202 }
 203
 204 /* This is only called until mem_init is done. */
 205 void __init *early_get_page(void)
 206 {
 207         void *p;
 208
 209         if (init_bootmem_done) {
 210                 p = alloc_bootmem_pages(PAGE_SIZE);
 211         } else {
 212                 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
 213                                         __initial_memory_limit_addr));
 214         }
 215         return p;
 216 }
 217
 218 /* Free up now-unused memory */
 219 static void free_sec(unsigned long start, unsigned long end, const char *name)
 220 {
 221         unsigned long cnt = 0;
 222
 223         while (start < end) {
 224                 ClearPageReserved(virt_to_page(start));
 225                 init_page_count(virt_to_page(start));
 226                 free_page(start);
 227                 cnt++;
 228                 start += PAGE_SIZE;
 229         }
 230         if (cnt) {
 231                 printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
 232                 totalram_pages += cnt;
 233         }
 234 }
 235
 236 void free_initmem(void)
 237 {
 238 #define FREESEC(TYPE) \
 239         free_sec((unsigned long)(&__ ## TYPE ## _begin), \
 240                  (unsigned long)(&__ ## TYPE ## _end), \
 241                  #TYPE);
 242
 243         printk ("Freeing unused kernel memory:");
 244         FREESEC(init);
 245         printk("\n");
 246         ppc_md.progress = NULL;
 247 #undef FREESEC
 248 }
 249
 250 #ifdef CONFIG_BLK_DEV_INITRD
 251 void free_initrd_mem(unsigned long start, unsigned long end)
 252 {
 253         if (start < end)
 254                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 255         for (; start < end; start += PAGE_SIZE) {
 256                 ClearPageReserved(virt_to_page(start));
 257                 init_page_count(virt_to_page(start));
 258                 free_page(start);
 259                 totalram_pages++;
 260         }
 261 }
 262 #endif
 263
 264 #ifdef CONFIG_PROC_KCORE
 265 static struct kcore_list kcore_vmem;
 266
 267 static int __init setup_kcore(void)
 268 {
 269         int i;
 270
 271         for (i = 0; i < lmb.memory.cnt; i++) {
 272                 unsigned long base;
 273                 unsigned long size;
 274                 struct kcore_list *kcore_mem;
 275
 276                 base = lmb.memory.region[i].base;
 277                 size = lmb.memory.region[i].size;
 278
 279                 kcore_mem = kmalloc(sizeof(struct kcore_list), GFP_ATOMIC);
 280                 if (!kcore_mem)
 281                         panic("%s: kmalloc failed\n", __func__);
 282
 283                 /* must stay under 32 bits */
 284                 if ( 0xfffffffful - (unsigned long)__va(base) < size) {
 285                         size = 0xfffffffful - (unsigned long)(__va(base));
 286                         printk(KERN_DEBUG "setup_kcore: restrict size=%lx\n",
 287                                                 size);
 288                 }
 289
 290                 kclist_add(kcore_mem, __va(base), size);
 291         }
 292
 293         kclist_add(&kcore_vmem, (void *)VMALLOC_START,
 294                 VMALLOC_END-VMALLOC_START);
 295
 296         return 0;
 297 }
 298 module_init(setup_kcore);
 299 #endif