arch/microblaze/mm/init.c

   1 /*
   2  * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2006 Atmark Techno, Inc.
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License. See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9
  10 #include <linux/bootmem.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/lmb.h>
  14 #include <linux/mm.h> /* mem_init */
  15 #include <linux/initrd.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/pfn.h>
  18 #include <linux/swap.h>
  19
  20 #include <asm/page.h>
  21 #include <asm/mmu_context.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/sections.h>
  24 #include <asm/tlb.h>
  25
  26 #ifndef CONFIG_MMU
  27 unsigned int __page_offset;
  28 EXPORT_SYMBOL(__page_offset);
  29
  30 #else
  31 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  32
  33 int mem_init_done;
  34 static int init_bootmem_done;
  35 #endif /* CONFIG_MMU */
  36
  37 char *klimit = _end;
  38
  39 /*
  40  * Initialize the bootmem system and give it all the memory we
  41  * have available.
  42  */
  43 unsigned long memory_start;
  44 unsigned long memory_end; /* due to mm/nommu.c */
  45 unsigned long memory_size;
  46
  47 /*
  48  * paging_init() sets up the page tables - in fact we've already done this.
  49  */
  50 static void __init paging_init(void)
  51 {
  52         unsigned long zones_size[MAX_NR_ZONES];
  53
  54         /* Clean every zones */
  55         memset(zones_size, 0, sizeof(zones_size));
  56
  57         /*
  58          * old: we can DMA to/from any address.put all page into ZONE_DMA
  59          * We use only ZONE_NORMAL
  60          */
  61         zones_size[ZONE_NORMAL] = max_mapnr;
  62
  63         free_area_init(zones_size);
  64 }
  65
  66 void __init setup_memory(void)
  67 {
  68         int i;
  69         unsigned long map_size;
  70 #ifndef CONFIG_MMU
  71         u32 kernel_align_start, kernel_align_size;
  72
  73         /* Find main memory where is the kernel */
  74         for (i = 0; i < lmb.memory.cnt; i++) {
  75                 memory_start = (u32) lmb.memory.region[i].base;
  76                 memory_end = (u32) lmb.memory.region[i].base
  77                                 + (u32) lmb.memory.region[i].size;
  78                 if ((memory_start <= (u32)_text) &&
  79                                         ((u32)_text <= memory_end)) {
  80                         memory_size = memory_end - memory_start;
  81                         PAGE_OFFSET = memory_start;
  82                         printk(KERN_INFO "%s: Main mem: 0x%x-0x%x, "
  83                                 "size 0x%08x\n", __func__, (u32) memory_start,
  84                                         (u32) memory_end, (u32) memory_size);
  85                         break;
  86                 }
  87         }
  88
  89         if (!memory_start || !memory_end) {
  90                 panic("%s: Missing memory setting 0x%08x-0x%08x\n",
  91                         __func__, (u32) memory_start, (u32) memory_end);
  92         }
  93
  94         /* reservation of region where is the kernel */
  95         kernel_align_start = PAGE_DOWN((u32)_text);
  96         /* ALIGN can be remove because _end in vmlinux.lds.S is align */
  97         kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
  98         lmb_reserve(kernel_align_start, kernel_align_size);
  99         printk(KERN_INFO "%s: kernel addr=0x%08x-0x%08x size=0x%08x\n",
 100                 __func__, kernel_align_start, kernel_align_start
 101                         + kernel_align_size, kernel_align_size);
 102
 103 #endif
 104         /*
 105          * Kernel:
 106          * start: base phys address of kernel - page align
 107          * end: base phys address of kernel - page align
 108          *
 109          * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 110          * max_low_pfn
 111          * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 112          * num_physpages - number of all pages
 113          */
 114
 115         /* memory start is from the kernel end (aligned) to higher addr */
 116         min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 117         /* RAM is assumed contiguous */
 118         num_physpages = max_mapnr = memory_size >> PAGE_SHIFT;
 119         max_pfn = max_low_pfn = memory_end >> PAGE_SHIFT;
 120
 121         printk(KERN_INFO "%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 122         printk(KERN_INFO "%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 123         printk(KERN_INFO "%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 124
 125         /*
 126          * Find an area to use for the bootmem bitmap.
 127          * We look for the first area which is at least
 128          * 128kB in length (128kB is enough for a bitmap
 129          * for 4GB of memory, using 4kB pages), plus 1 page
 130          * (in case the address isn't page-aligned).
 131          */
 132 #ifndef CONFIG_MMU
 133         map_size = init_bootmem_node(NODE_DATA(0), PFN_UP(TOPHYS((u32)klimit)),
 134                                         min_low_pfn, max_low_pfn);
 135 #else
 136         map_size = init_bootmem_node(&contig_page_data,
 137                 PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn);
 138 #endif
 139         lmb_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size);
 140
 141         /* free bootmem is whole main memory */
 142         free_bootmem(memory_start, memory_size);
 143
 144         /* reserve allocate blocks */
 145         for (i = 0; i < lmb.reserved.cnt; i++) {
 146                 pr_debug("reserved %d - 0x%08x-0x%08x\n", i,
 147                         (u32) lmb.reserved.region[i].base,
 148                         (u32) lmb_size_bytes(&lmb.reserved, i));
 149                 reserve_bootmem(lmb.reserved.region[i].base,
 150                         lmb_size_bytes(&lmb.reserved, i) - 1, BOOTMEM_DEFAULT);
 151         }
 152 #ifdef CONFIG_MMU
 153         init_bootmem_done = 1;
 154 #endif
 155         paging_init();
 156 }
 157
 158 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 159 {
 160         unsigned long addr;
 161
 162         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 163                 ClearPageReserved(virt_to_page(addr));
 164                 init_page_count(virt_to_page(addr));
 165                 memset((void *)addr, 0xcc, PAGE_SIZE);
 166                 free_page(addr);
 167                 totalram_pages++;
 168         }
 169         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 170 }
 171
 172 #ifdef CONFIG_BLK_DEV_INITRD
 173 void free_initrd_mem(unsigned long start, unsigned long end)
 174 {
 175         int pages = 0;
 176         for (; start < end; start += PAGE_SIZE) {
 177                 ClearPageReserved(virt_to_page(start));
 178                 init_page_count(virt_to_page(start));
 179                 free_page(start);
 180                 totalram_pages++;
 181                 pages++;
 182         }
 183         printk(KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
 184 }
 185 #endif
 186
 187 void free_initmem(void)
 188 {
 189         free_init_pages("unused kernel memory",
 190                         (unsigned long)(&__init_begin),
 191                         (unsigned long)(&__init_end));
 192 }
 193
 194 /* FIXME from arch/powerpc/mm/mem.c*/
 195 void show_mem(void)
 196 {
 197         printk(KERN_NOTICE "%s\n", __func__);
 198 }
 199
 200 void __init mem_init(void)
 201 {
 202         high_memory = (void *)__va(memory_end);
 203         /* this will put all memory onto the freelists */
 204         totalram_pages += free_all_bootmem();
 205
 206         printk(KERN_INFO "Memory: %luk/%luk available\n",
 207                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 208                num_physpages << (PAGE_SHIFT-10));
 209 #ifdef CONFIG_MMU
 210         mem_init_done = 1;
 211 #endif
 212 }
 213
 214 #ifndef CONFIG_MMU
 215 /* Check against bounds of physical memory */
 216 int ___range_ok(unsigned long addr, unsigned long size)
 217 {
 218         return ((addr < memory_start) ||
 219                 ((addr + size) > memory_end));
 220 }
 221 EXPORT_SYMBOL(___range_ok);
 222
 223 #else
 224 int page_is_ram(unsigned long pfn)
 225 {
 226         return pfn < max_low_pfn;
 227 }
 228
 229 /*
 230  * Check for command-line options that affect what MMU_init will do.
 231  */
 232 static void mm_cmdline_setup(void)
 233 {
 234         unsigned long maxmem = 0;
 235         char *p = cmd_line;
 236
 237         /* Look for mem= option on command line */
 238         p = strstr(cmd_line, "mem=");
 239         if (p) {
 240                 p += 4;
 241                 maxmem = memparse(p, &p);
 242                 if (maxmem && memory_size > maxmem) {
 243                         memory_size = maxmem;
 244                         memory_end = memory_start + memory_size;
 245                         lmb.memory.region[0].size = memory_size;
 246                 }
 247         }
 248 }
 249
 250 /*
 251  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 252  */
 253 static void __init mmu_init_hw(void)
 254 {
 255         /*
 256          * The Zone Protection Register (ZPR) defines how protection will
 257          * be applied to every page which is a member of a given zone. At
 258          * present, we utilize only two of the zones.
 259          * The zone index bits (of ZSEL) in the PTE are used for software
 260          * indicators, except the LSB.  For user access, zone 1 is used,
 261          * for kernel access, zone 0 is used.  We set all but zone 1
 262          * to zero, allowing only kernel access as indicated in the PTE.
 263          * For zone 1, we set a 01 binary (a value of 10 will not work)
 264          * to allow user access as indicated in the PTE.  This also allows
 265          * kernel access as indicated in the PTE.
 266          */
 267         __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
 268                         "mts rzpr, r11;"
 269                         : : : "r11");
 270 }
 271
 272 /*
 273  * MMU_init sets up the basic memory mappings for the kernel,
 274  * including both RAM and possibly some I/O regions,
 275  * and sets up the page tables and the MMU hardware ready to go.
 276  */
 277
 278 /* called from head.S */
 279 asmlinkage void __init mmu_init(void)
 280 {
 281         unsigned int kstart, ksize;
 282
 283         if (!lmb.reserved.cnt) {
 284                 printk(KERN_EMERG "Error memory count\n");
 285                 machine_restart(NULL);
 286         }
 287
 288         if ((u32) lmb.memory.region[0].size < 0x1000000) {
 289                 printk(KERN_EMERG "Memory must be greater than 16MB\n");
 290                 machine_restart(NULL);
 291         }
 292         /* Find main memory where the kernel is */
 293         memory_start = (u32) lmb.memory.region[0].base;
 294         memory_end = (u32) lmb.memory.region[0].base +
 295                                 (u32) lmb.memory.region[0].size;
 296         memory_size = memory_end - memory_start;
 297
 298         mm_cmdline_setup(); /* FIXME parse args from command line - not used */
 299
 300         /*
 301          * Map out the kernel text/data/bss from the available physical
 302          * memory.
 303          */
 304         kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 305         /* kernel size */
 306         ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 307         lmb_reserve(kstart, ksize);
 308
 309 #if defined(CONFIG_BLK_DEV_INITRD)
 310         /* Remove the init RAM disk from the available memory. */
 311 /*      if (initrd_start) {
 312                 mem_pieces_remove(&phys_avail, __pa(initrd_start),
 313                                   initrd_end - initrd_start, 1);
 314         }*/
 315 #endif /* CONFIG_BLK_DEV_INITRD */
 316
 317         /* Initialize the MMU hardware */
 318         mmu_init_hw();
 319
 320         /* Map in all of RAM starting at CONFIG_KERNEL_START */
 321         mapin_ram();
 322
 323 #ifdef HIGHMEM_START_BOOL
 324         ioremap_base = HIGHMEM_START;
 325 #else
 326         ioremap_base = 0xfe000000UL;    /* for now, could be 0xfffff000 */
 327 #endif /* CONFIG_HIGHMEM */
 328         ioremap_bot = ioremap_base;
 329
 330         /* Initialize the context management stuff */
 331         mmu_context_init();
 332 }
 333
 334 /* This is only called until mem_init is done. */
 335 void __init *early_get_page(void)
 336 {
 337         void *p;
 338         if (init_bootmem_done) {
 339                 p = alloc_bootmem_pages(PAGE_SIZE);
 340         } else {
 341                 /*
 342                  * Mem start + 32MB -> here is limit
 343                  * because of mem mapping from head.S
 344                  */
 345                 p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
 346                                         memory_start + 0x2000000));
 347         }
 348         return p;
 349 }
 350 #endif /* CONFIG_MMU */