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init.c

/*
 *  linux/arch/arm/mm/init.c
 *
 *  Copyright (C) 1995-2005 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/sort.h>

#include <asm/mach-types.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>

#include <asm/mach/arch.h>
#include <asm/mach/map.h>

#include "mm.h"

static unsigned long phys_initrd_start __initdata = 0;
static unsigned long phys_initrd_size __initdata = 0;

static int __init early_initrd(char *p)
{
      unsigned long start, size;
      char *endp;

      start = memparse(p, &endp);
      if (*endp == ',') {
            size = memparse(endp + 1, NULL);

            phys_initrd_start = start;
            phys_initrd_size = size;
      }
      return 0;
}
early_param("initrd", early_initrd);

static int __init parse_tag_initrd(const struct tag *tag)
{
      printk(KERN_WARNING "ATAG_INITRD is deprecated; "
            "please update your bootloader.\n");
      phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
      phys_initrd_size = tag->u.initrd.size;
      return 0;
}

__tagtable(ATAG_INITRD, parse_tag_initrd);

static int __init parse_tag_initrd2(const struct tag *tag)
{
      phys_initrd_start = tag->u.initrd.start;
      phys_initrd_size = tag->u.initrd.size;
      return 0;
}

__tagtable(ATAG_INITRD2, parse_tag_initrd2);

/*
 * This keeps memory configuration data used by a couple memory
 * initialization functions, as well as show_mem() for the skipping
 * of holes in the memory map.  It is populated by arm_add_memory().
 */
struct meminfo meminfo;

void show_mem(void)
{
      int free = 0, total = 0, reserved = 0;
      int shared = 0, cached = 0, slab = 0, i;
      struct meminfo * mi = &meminfo;

      printk("Mem-info:\n");
      show_free_areas();

      for_each_bank (i, mi) {
            struct membank *bank = &mi->bank[i];
            unsigned int pfn1, pfn2;
            struct page *page, *end;

            pfn1 = bank_pfn_start(bank);
            pfn2 = bank_pfn_end(bank);

            page = pfn_to_page(pfn1);
            end  = pfn_to_page(pfn2 - 1) + 1;

            do {
                  total++;
                  if (PageReserved(page))
                        reserved++;
                  else if (PageSwapCache(page))
                        cached++;
                  else if (PageSlab(page))
                        slab++;
                  else if (!page_count(page))
                        free++;
                  else
                        shared += page_count(page) - 1;
                  page++;
            } while (page < end);
      }

      printk("%d pages of RAM\n", total);
      printk("%d free pages\n", free);
      printk("%d reserved pages\n", reserved);
      printk("%d slab pages\n", slab);
      printk("%d pages shared\n", shared);
      printk("%d pages swap cached\n", cached);
}

static void __init find_limits(unsigned long *min, unsigned long *max_low,
      unsigned long *max_high)
{
      struct meminfo *mi = &meminfo;
      int i;

      *min = -1UL;
      *max_low = *max_high = 0;

      for_each_bank (i, mi) {
            struct membank *bank = &mi->bank[i];
            unsigned long start, end;

            start = bank_pfn_start(bank);
            end = bank_pfn_end(bank);

            if (*min > start)
                  *min = start;
            if (*max_high < end)
                  *max_high = end;
            if (bank->highmem)
                  continue;
            if (*max_low < end)
                  *max_low = end;
      }
}

static void __init arm_bootmem_init(unsigned long start_pfn,
      unsigned long end_pfn)
{
      struct memblock_region *reg;
      unsigned int boot_pages;
      phys_addr_t bitmap;
      pg_data_t *pgdat;

      /*
       * Allocate the bootmem bitmap page.  This must be in a region
       * of memory which has already been mapped.
       */
      boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
      bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
                        __pfn_to_phys(end_pfn));

      /*
       * Initialise the bootmem allocator, handing the
       * memory banks over to bootmem.
       */
      node_set_online(0);
      pgdat = NODE_DATA(0);
      init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

      /* Free the lowmem regions from memblock into bootmem. */
      for_each_memblock(memory, reg) {
            unsigned long start = memblock_region_memory_base_pfn(reg);
            unsigned long end = memblock_region_memory_end_pfn(reg);

            if (end >= end_pfn)
                  end = end_pfn;
            if (start >= end)
                  break;

            free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
      }

      /* Reserve the lowmem memblock reserved regions in bootmem. */
      for_each_memblock(reserved, reg) {
            unsigned long start = memblock_region_reserved_base_pfn(reg);
            unsigned long end = memblock_region_reserved_end_pfn(reg);

            if (end >= end_pfn)
                  end = end_pfn;
            if (start >= end)
                  break;

            reserve_bootmem(__pfn_to_phys(start),
                          (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
      }
}

static void __init arm_bootmem_free(unsigned long min, unsigned long max_low,
      unsigned long max_high)
{
      unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
      struct memblock_region *reg;

      /*
       * initialise the zones.
       */
      memset(zone_size, 0, sizeof(zone_size));

      /*
       * The memory size has already been determined.  If we need
       * to do anything fancy with the allocation of this memory
       * to the zones, now is the time to do it.
       */
      zone_size[0] = max_low - min;
#ifdef CONFIG_HIGHMEM
      zone_size[ZONE_HIGHMEM] = max_high - max_low;
#endif

      /*
       * Calculate the size of the holes.
       *  holes = node_size - sum(bank_sizes)
       */
      memcpy(zhole_size, zone_size, sizeof(zhole_size));
      for_each_memblock(memory, reg) {
            unsigned long start = memblock_region_memory_base_pfn(reg);
            unsigned long end = memblock_region_memory_end_pfn(reg);

            if (start < max_low) {
                  unsigned long low_end = min(end, max_low);
                  zhole_size[0] -= low_end - start;
            }
#ifdef CONFIG_HIGHMEM
            if (end > max_low) {
                  unsigned long high_start = max(start, max_low);
                  zhole_size[ZONE_HIGHMEM] -= end - high_start;
            }
#endif
      }

      /*
       * Adjust the sizes according to any special requirements for
       * this machine type.
       */
      arch_adjust_zones(zone_size, zhole_size);

      free_area_init_node(0, zone_size, min, zhole_size);
}

#ifndef CONFIG_SPARSEMEM
int pfn_valid(unsigned long pfn)
{
      return memblock_is_memory(pfn << PAGE_SHIFT);
}
EXPORT_SYMBOL(pfn_valid);

static void arm_memory_present(void)
{
}
#else
static void arm_memory_present(void)
{
      struct memblock_region *reg;

      for_each_memblock(memory, reg)
            memory_present(0, memblock_region_memory_base_pfn(reg),
                         memblock_region_memory_end_pfn(reg));
}
#endif

static int __init meminfo_cmp(const void *_a, const void *_b)
{
      const struct membank *a = _a, *b = _b;
      long cmp = bank_pfn_start(a) - bank_pfn_start(b);
      return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
}

void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
{
      int i;

      sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]), meminfo_cmp, NULL);

      memblock_init();
      for (i = 0; i < mi->nr_banks; i++)
            memblock_add(mi->bank[i].start, mi->bank[i].size);

      /* Register the kernel text, kernel data and initrd with memblock. */
#ifdef CONFIG_XIP_KERNEL
      memblock_reserve(__pa(_sdata), _end - _sdata);
#else
      memblock_reserve(__pa(_stext), _end - _stext);
#endif
#ifdef CONFIG_BLK_DEV_INITRD
      if (phys_initrd_size) {
            memblock_reserve(phys_initrd_start, phys_initrd_size);

            /* Now convert initrd to virtual addresses */
            initrd_start = __phys_to_virt(phys_initrd_start);
            initrd_end = initrd_start + phys_initrd_size;
      }
#endif

      arm_mm_memblock_reserve();

      /* reserve any platform specific memblock areas */
      if (mdesc->reserve)
            mdesc->reserve();

      memblock_analyze();
      memblock_dump_all();
}

void __init bootmem_init(void)
{
      unsigned long min, max_low, max_high;

      max_low = max_high = 0;

      find_limits(&min, &max_low, &max_high);

      arm_bootmem_init(min, max_low);

      /*
       * Sparsemem tries to allocate bootmem in memory_present(),
       * so must be done after the fixed reservations
       */
      arm_memory_present();

      /*
       * sparse_init() needs the bootmem allocator up and running.
       */
      sparse_init();

      /*
       * Now free the memory - free_area_init_node needs
       * the sparse mem_map arrays initialized by sparse_init()
       * for memmap_init_zone(), otherwise all PFNs are invalid.
       */
      arm_bootmem_free(min, max_low, max_high);

      high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;

      /*
       * This doesn't seem to be used by the Linux memory manager any
       * more, but is used by ll_rw_block.  If we can get rid of it, we
       * also get rid of some of the stuff above as well.
       *
       * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
       * the system, not the maximum PFN.
       */
      max_low_pfn = max_low - PHYS_PFN_OFFSET;
      max_pfn = max_high - PHYS_PFN_OFFSET;
}

static inline int free_area(unsigned long pfn, unsigned long end, char *s)
{
      unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);

      for (; pfn < end; pfn++) {
            struct page *page = pfn_to_page(pfn);
            ClearPageReserved(page);
            init_page_count(page);
            __free_page(page);
            pages++;
      }

      if (size && s)
            printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);

      return pages;
}

static inline void
free_memmap(unsigned long start_pfn, unsigned long end_pfn)
{
      struct page *start_pg, *end_pg;
      unsigned long pg, pgend;

      /*
       * Convert start_pfn/end_pfn to a struct page pointer.
       */
      start_pg = pfn_to_page(start_pfn - 1) + 1;
      end_pg = pfn_to_page(end_pfn);

      /*
       * Convert to physical addresses, and
       * round start upwards and end downwards.
       */
      pg = PAGE_ALIGN(__pa(start_pg));
      pgend = __pa(end_pg) & PAGE_MASK;

      /*
       * If there are free pages between these,
       * free the section of the memmap array.
       */
      if (pg < pgend)
            free_bootmem(pg, pgend - pg);
}

/*
 * The mem_map array can get very big.  Free the unused area of the memory map.
 */
static void __init free_unused_memmap(struct meminfo *mi)
{
      unsigned long bank_start, prev_bank_end = 0;
      unsigned int i;

      /*
       * This relies on each bank being in address order.
       * The banks are sorted previously in bootmem_init().
       */
      for_each_bank(i, mi) {
            struct membank *bank = &mi->bank[i];

            bank_start = bank_pfn_start(bank);

            /*
             * If we had a previous bank, and there is a space
             * between the current bank and the previous, free it.
             */
            if (prev_bank_end && prev_bank_end < bank_start)
                  free_memmap(prev_bank_end, bank_start);

            /*
             * Align up here since the VM subsystem insists that the
             * memmap entries are valid from the bank end aligned to
             * MAX_ORDER_NR_PAGES.
             */
            prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
      }
}

static void __init free_highpages(void)
{
#ifdef CONFIG_HIGHMEM
      unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
      struct memblock_region *mem, *res;

      /* set highmem page free */
      for_each_memblock(memory, mem) {
            unsigned long start = memblock_region_memory_base_pfn(mem);
            unsigned long end = memblock_region_memory_end_pfn(mem);

            /* Ignore complete lowmem entries */
            if (end <= max_low)
                  continue;

            /* Truncate partial highmem entries */
            if (start < max_low)
                  start = max_low;

            /* Find and exclude any reserved regions */
            for_each_memblock(reserved, res) {
                  unsigned long res_start, res_end;

                  res_start = memblock_region_reserved_base_pfn(res);
                  res_end = memblock_region_reserved_end_pfn(res);

                  if (res_end < start)
                        continue;
                  if (res_start < start)
                        res_start = start;
                  if (res_start > end)
                        res_start = end;
                  if (res_end > end)
                        res_end = end;
                  if (res_start != start)
                        totalhigh_pages += free_area(start, res_start,
                                               NULL);
                  start = res_end;
                  if (start == end)
                        break;
            }

            /* And now free anything which remains */
            if (start < end)
                  totalhigh_pages += free_area(start, end, NULL);
      }
      totalram_pages += totalhigh_pages;
#endif
}

/*
 * mem_init() marks the free areas in the mem_map and tells us how much
 * memory is free.  This is done after various parts of the system have
 * claimed their memory after the kernel image.
 */
void __init mem_init(void)
{
      unsigned long reserved_pages, free_pages;
      struct memblock_region *reg;
      int i;
#ifdef CONFIG_HAVE_TCM
      /* These pointers are filled in on TCM detection */
      extern u32 dtcm_end;
      extern u32 itcm_end;
#endif

      max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;

      /* this will put all unused low memory onto the freelists */
      free_unused_memmap(&meminfo);

      totalram_pages += free_all_bootmem();

#ifdef CONFIG_SA1111
      /* now that our DMA memory is actually so designated, we can free it */
      totalram_pages += free_area(PHYS_PFN_OFFSET,
                            __phys_to_pfn(__pa(swapper_pg_dir)), NULL);
#endif

      free_highpages();

      reserved_pages = free_pages = 0;

      for_each_bank(i, &meminfo) {
            struct membank *bank = &meminfo.bank[i];
            unsigned int pfn1, pfn2;
            struct page *page, *end;

            pfn1 = bank_pfn_start(bank);
            pfn2 = bank_pfn_end(bank);

            page = pfn_to_page(pfn1);
            end  = pfn_to_page(pfn2 - 1) + 1;

            do {
                  if (PageReserved(page))
                        reserved_pages++;
                  else if (!page_count(page))
                        free_pages++;
                  page++;
            } while (page < end);
      }

      /*
       * Since our memory may not be contiguous, calculate the
       * real number of pages we have in this system
       */
      printk(KERN_INFO "Memory:");
      num_physpages = 0;
      for_each_memblock(memory, reg) {
            unsigned long pages = memblock_region_memory_end_pfn(reg) -
                  memblock_region_memory_base_pfn(reg);
            num_physpages += pages;
            printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
      }
      printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));

      printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
            nr_free_pages() << (PAGE_SHIFT-10),
            free_pages << (PAGE_SHIFT-10),
            reserved_pages << (PAGE_SHIFT-10),
            totalhigh_pages << (PAGE_SHIFT-10));

#define MLK(b, t) b, t, ((t) - (b)) >> 10
#define MLM(b, t) b, t, ((t) - (b)) >> 20
#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)

      printk(KERN_NOTICE "Virtual kernel memory layout:\n"
                  "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#ifdef CONFIG_HAVE_TCM
                  "    DTCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                  "    ITCM    : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#endif
                  "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#ifdef CONFIG_MMU
                  "    DMA     : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#endif
                  "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
                  "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#ifdef CONFIG_HIGHMEM
                  "    pkmap   : 0x%08lx - 0x%08lx   (%4ld MB)\n"
#endif
                  "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
                  "      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
                  "      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
                  "      .data : 0x%p" " - 0x%p" "   (%4d kB)\n",

                  MLK(UL(CONFIG_VECTORS_BASE), UL(CONFIG_VECTORS_BASE) +
                        (PAGE_SIZE)),
#ifdef CONFIG_HAVE_TCM
                  MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
                  MLK(ITCM_OFFSET, (unsigned long) itcm_end),
#endif
                  MLK(FIXADDR_START, FIXADDR_TOP),
#ifdef CONFIG_MMU
                  MLM(CONSISTENT_BASE, CONSISTENT_END),
#endif
                  MLM(VMALLOC_START, VMALLOC_END),
                  MLM(PAGE_OFFSET, (unsigned long)high_memory),
#ifdef CONFIG_HIGHMEM
                  MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
                        (PAGE_SIZE)),
#endif
                  MLM(MODULES_VADDR, MODULES_END),

                  MLK_ROUNDUP(__init_begin, __init_end),
                  MLK_ROUNDUP(_text, _etext),
                  MLK_ROUNDUP(_sdata, _edata));

#undef MLK
#undef MLM
#undef MLK_ROUNDUP

      /*
       * Check boundaries twice: Some fundamental inconsistencies can
       * be detected at build time already.
       */
#ifdef CONFIG_MMU
      BUILD_BUG_ON(VMALLOC_END                  > CONSISTENT_BASE);
      BUG_ON(VMALLOC_END                        > CONSISTENT_BASE);

      BUILD_BUG_ON(TASK_SIZE                    > MODULES_VADDR);
      BUG_ON(TASK_SIZE                    > MODULES_VADDR);
#endif

#ifdef CONFIG_HIGHMEM
      BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
      BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE      > PAGE_OFFSET);
#endif

      if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
            extern int sysctl_overcommit_memory;
            /*
             * On a machine this small we won't get
             * anywhere without overcommit, so turn
             * it on by default.
             */
            sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
      }
}

void free_initmem(void)
{
#ifdef CONFIG_HAVE_TCM
      extern char __tcm_start, __tcm_end;

      totalram_pages += free_area(__phys_to_pfn(__pa(&__tcm_start)),
                            __phys_to_pfn(__pa(&__tcm_end)),
                            "TCM link");
#endif

      if (!machine_is_integrator() && !machine_is_cintegrator())
            totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
                                  __phys_to_pfn(__pa(__init_end)),
                                  "init");
}

#ifdef CONFIG_BLK_DEV_INITRD

static int keep_initrd;

void free_initrd_mem(unsigned long start, unsigned long end)
{
      if (!keep_initrd)
            totalram_pages += free_area(__phys_to_pfn(__pa(start)),
                                  __phys_to_pfn(__pa(end)),
                                  "initrd");
}

static int __init keepinitrd_setup(char *__unused)
{
      keep_initrd = 1;
      return 1;
}

__setup("keepinitrd", keepinitrd_setup);
#endif

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