linux/arch/microblaze/mm/init.c
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   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/dma-map-ops.h>
  11#include <linux/memblock.h>
  12#include <linux/init.h>
  13#include <linux/kernel.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/slab.h>
  19#include <linux/swap.h>
  20#include <linux/export.h>
  21
  22#include <asm/page.h>
  23#include <asm/mmu_context.h>
  24#include <asm/pgalloc.h>
  25#include <asm/sections.h>
  26#include <asm/tlb.h>
  27#include <asm/fixmap.h>
  28
  29/* Use for MMU and noMMU because of PCI generic code */
  30int mem_init_done;
  31
  32char *klimit = _end;
  33
  34/*
  35 * Initialize the bootmem system and give it all the memory we
  36 * have available.
  37 */
  38unsigned long memory_start;
  39EXPORT_SYMBOL(memory_start);
  40unsigned long memory_size;
  41EXPORT_SYMBOL(memory_size);
  42unsigned long lowmem_size;
  43
  44EXPORT_SYMBOL(min_low_pfn);
  45EXPORT_SYMBOL(max_low_pfn);
  46
  47#ifdef CONFIG_HIGHMEM
  48static void __init highmem_init(void)
  49{
  50        pr_debug("%x\n", (u32)PKMAP_BASE);
  51        map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
  52        pkmap_page_table = virt_to_kpte(PKMAP_BASE);
  53}
  54
  55static void __meminit highmem_setup(void)
  56{
  57        unsigned long pfn;
  58
  59        for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
  60                struct page *page = pfn_to_page(pfn);
  61
  62                /* FIXME not sure about */
  63                if (!memblock_is_reserved(pfn << PAGE_SHIFT))
  64                        free_highmem_page(page);
  65        }
  66}
  67#endif /* CONFIG_HIGHMEM */
  68
  69/*
  70 * paging_init() sets up the page tables - in fact we've already done this.
  71 */
  72static void __init paging_init(void)
  73{
  74        unsigned long zones_size[MAX_NR_ZONES];
  75        int idx;
  76
  77        /* Setup fixmaps */
  78        for (idx = 0; idx < __end_of_fixed_addresses; idx++)
  79                clear_fixmap(idx);
  80
  81        /* Clean every zones */
  82        memset(zones_size, 0, sizeof(zones_size));
  83
  84#ifdef CONFIG_HIGHMEM
  85        highmem_init();
  86
  87        zones_size[ZONE_DMA] = max_low_pfn;
  88        zones_size[ZONE_HIGHMEM] = max_pfn;
  89#else
  90        zones_size[ZONE_DMA] = max_pfn;
  91#endif
  92
  93        /* We don't have holes in memory map */
  94        free_area_init(zones_size);
  95}
  96
  97void __init setup_memory(void)
  98{
  99        /*
 100         * Kernel:
 101         * start: base phys address of kernel - page align
 102         * end: base phys address of kernel - page align
 103         *
 104         * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 105         * max_low_pfn
 106         * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 107         */
 108
 109        /* memory start is from the kernel end (aligned) to higher addr */
 110        min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 111        /* RAM is assumed contiguous */
 112        max_mapnr = memory_size >> PAGE_SHIFT;
 113        max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
 114        max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
 115
 116        pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 117        pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 118        pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 119        pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
 120
 121        paging_init();
 122}
 123
 124void __init mem_init(void)
 125{
 126        high_memory = (void *)__va(memory_start + lowmem_size - 1);
 127
 128        /* this will put all memory onto the freelists */
 129        memblock_free_all();
 130#ifdef CONFIG_HIGHMEM
 131        highmem_setup();
 132#endif
 133
 134        mem_init_done = 1;
 135}
 136
 137int page_is_ram(unsigned long pfn)
 138{
 139        return pfn < max_low_pfn;
 140}
 141
 142/*
 143 * Check for command-line options that affect what MMU_init will do.
 144 */
 145static void mm_cmdline_setup(void)
 146{
 147        unsigned long maxmem = 0;
 148        char *p = cmd_line;
 149
 150        /* Look for mem= option on command line */
 151        p = strstr(cmd_line, "mem=");
 152        if (p) {
 153                p += 4;
 154                maxmem = memparse(p, &p);
 155                if (maxmem && memory_size > maxmem) {
 156                        memory_size = maxmem;
 157                        memblock.memory.regions[0].size = memory_size;
 158                }
 159        }
 160}
 161
 162/*
 163 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 164 */
 165static void __init mmu_init_hw(void)
 166{
 167        /*
 168         * The Zone Protection Register (ZPR) defines how protection will
 169         * be applied to every page which is a member of a given zone. At
 170         * present, we utilize only two of the zones.
 171         * The zone index bits (of ZSEL) in the PTE are used for software
 172         * indicators, except the LSB.  For user access, zone 1 is used,
 173         * for kernel access, zone 0 is used.  We set all but zone 1
 174         * to zero, allowing only kernel access as indicated in the PTE.
 175         * For zone 1, we set a 01 binary (a value of 10 will not work)
 176         * to allow user access as indicated in the PTE.  This also allows
 177         * kernel access as indicated in the PTE.
 178         */
 179        __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
 180                        "mts rzpr, r11;"
 181                        : : : "r11");
 182}
 183
 184/*
 185 * MMU_init sets up the basic memory mappings for the kernel,
 186 * including both RAM and possibly some I/O regions,
 187 * and sets up the page tables and the MMU hardware ready to go.
 188 */
 189
 190/* called from head.S */
 191asmlinkage void __init mmu_init(void)
 192{
 193        unsigned int kstart, ksize;
 194
 195        if (!memblock.reserved.cnt) {
 196                pr_emerg("Error memory count\n");
 197                machine_restart(NULL);
 198        }
 199
 200        if ((u32) memblock.memory.regions[0].size < 0x400000) {
 201                pr_emerg("Memory must be greater than 4MB\n");
 202                machine_restart(NULL);
 203        }
 204
 205        if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
 206                pr_emerg("Kernel size is greater than memory node\n");
 207                machine_restart(NULL);
 208        }
 209
 210        /* Find main memory where the kernel is */
 211        memory_start = (u32) memblock.memory.regions[0].base;
 212        lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
 213
 214        if (lowmem_size > CONFIG_LOWMEM_SIZE) {
 215                lowmem_size = CONFIG_LOWMEM_SIZE;
 216#ifndef CONFIG_HIGHMEM
 217                memory_size = lowmem_size;
 218#endif
 219        }
 220
 221        mm_cmdline_setup(); /* FIXME parse args from command line - not used */
 222
 223        /*
 224         * Map out the kernel text/data/bss from the available physical
 225         * memory.
 226         */
 227        kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 228        /* kernel size */
 229        ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 230        memblock_reserve(kstart, ksize);
 231
 232#if defined(CONFIG_BLK_DEV_INITRD)
 233        /* Remove the init RAM disk from the available memory. */
 234        if (initrd_start) {
 235                unsigned long size;
 236                size = initrd_end - initrd_start;
 237                memblock_reserve(__virt_to_phys(initrd_start), size);
 238        }
 239#endif /* CONFIG_BLK_DEV_INITRD */
 240
 241        /* Initialize the MMU hardware */
 242        mmu_init_hw();
 243
 244        /* Map in all of RAM starting at CONFIG_KERNEL_START */
 245        mapin_ram();
 246
 247        /* Extend vmalloc and ioremap area as big as possible */
 248#ifdef CONFIG_HIGHMEM
 249        ioremap_base = ioremap_bot = PKMAP_BASE;
 250#else
 251        ioremap_base = ioremap_bot = FIXADDR_START;
 252#endif
 253
 254        /* Initialize the context management stuff */
 255        mmu_context_init();
 256
 257        /* Shortly after that, the entire linear mapping will be available */
 258        /* This will also cause that unflatten device tree will be allocated
 259         * inside 768MB limit */
 260        memblock_set_current_limit(memory_start + lowmem_size - 1);
 261
 262        parse_early_param();
 263
 264        /* CMA initialization */
 265        dma_contiguous_reserve(memory_start + lowmem_size - 1);
 266}
 267
 268/* This is only called until mem_init is done. */
 269void __init *early_get_page(void)
 270{
 271        /*
 272         * Mem start + kernel_tlb -> here is limit
 273         * because of mem mapping from head.S
 274         */
 275        return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
 276                                MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
 277                                NUMA_NO_NODE);
 278}
 279
 280void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
 281{
 282        void *p;
 283
 284        if (mem_init_done) {
 285                p = kzalloc(size, mask);
 286        } else {
 287                p = memblock_alloc(size, SMP_CACHE_BYTES);
 288                if (!p)
 289                        panic("%s: Failed to allocate %zu bytes\n",
 290                              __func__, size);
 291        }
 292
 293        return p;
 294}
 295