LXR linux/arch/nios2/mm/init.c

   1/*
   2 * Copyright (C) 2013 Altera Corporation
   3 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
   4 * Copyright (C) 2009 Wind River Systems Inc
   5 *   Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
   6 * Copyright (C) 2004 Microtronix Datacom Ltd
   7 *
   8 * based on arch/m68k/mm/init.c
   9 *
  10 * This file is subject to the terms and conditions of the GNU General Public
  11 * License. See the file "COPYING" in the main directory of this archive
  12 * for more details.
  13 */
  14
  15#include <linux/signal.h>
  16#include <linux/sched.h>
  17#include <linux/kernel.h>
  18#include <linux/errno.h>
  19#include <linux/string.h>
  20#include <linux/types.h>
  21#include <linux/ptrace.h>
  22#include <linux/mman.h>
  23#include <linux/mm.h>
  24#include <linux/init.h>
  25#include <linux/pagemap.h>
  26#include <linux/memblock.h>
  27#include <linux/slab.h>
  28#include <linux/binfmts.h>
  29
  30#include <asm/setup.h>
  31#include <asm/page.h>
  32#include <asm/sections.h>
  33#include <asm/tlb.h>
  34#include <asm/mmu_context.h>
  35#include <asm/cpuinfo.h>
  36#include <asm/processor.h>
  37
  38pgd_t *pgd_current;
  39
  40/*
  41 * paging_init() continues the virtual memory environment setup which
  42 * was begun by the code in arch/head.S.
  43 * The parameters are pointers to where to stick the starting and ending
  44 * addresses of available kernel virtual memory.
  45 */
  46void __init paging_init(void)
  47{
  48        unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
  49
  50        pagetable_init();
  51        pgd_current = swapper_pg_dir;
  52
  53        max_zone_pfn[ZONE_NORMAL] = max_mapnr;
  54
  55        /* pass the memory from the bootmem allocator to the main allocator */
  56        free_area_init(max_zone_pfn);
  57
  58        flush_dcache_range((unsigned long)empty_zero_page,
  59                        (unsigned long)empty_zero_page + PAGE_SIZE);
  60}
  61
  62void __init mem_init(void)
  63{
  64        unsigned long end_mem   = memory_end; /* this must not include
  65                                                kernel stack at top */
  66
  67        pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
  68
  69        end_mem &= PAGE_MASK;
  70        high_memory = __va(end_mem);
  71
  72        /* this will put all memory onto the freelists */
  73        memblock_free_all();
  74}
  75
  76void __init mmu_init(void)
  77{
  78        flush_tlb_all();
  79}
  80
  81#define __page_aligned(order) __aligned(PAGE_SIZE << (order))
  82pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
  83pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
  84static struct page *kuser_page[1];
  85
  86static int alloc_kuser_page(void)
  87{
  88        extern char __kuser_helper_start[], __kuser_helper_end[];
  89        int kuser_sz = __kuser_helper_end - __kuser_helper_start;
  90        unsigned long vpage;
  91
  92        vpage = get_zeroed_page(GFP_ATOMIC);
  93        if (!vpage)
  94                return -ENOMEM;
  95
  96        /* Copy kuser helpers */
  97        memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
  98
  99        flush_icache_range(vpage, vpage + KUSER_SIZE);
 100        kuser_page[0] = virt_to_page(vpage);
 101
 102        return 0;
 103}
 104arch_initcall(alloc_kuser_page);
 105
 106int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 107{
 108        struct mm_struct *mm = current->mm;
 109        int ret;
 110
 111        mmap_write_lock(mm);
 112
 113        /* Map kuser helpers to user space address */
 114        ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
 115                                      VM_READ | VM_EXEC | VM_MAYREAD |
 116                                      VM_MAYEXEC, kuser_page);
 117
 118        mmap_write_unlock(mm);
 119
 120        return ret;
 121}
 122
 123const char *arch_vma_name(struct vm_area_struct *vma)
 124{
 125        return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
 126}
 127