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