root/arch/nios2/mm/init.c

DEFINITIONS

1. paging_init
2. mem_init
3. mmu_init
4. alloc_kuser_page
5. arch_setup_additional_pages
6. arch_vma_name

   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/pgtable.h>
  33 #include <asm/sections.h>
  34 #include <asm/tlb.h>
  35 #include <asm/mmu_context.h>
  36 #include <asm/cpuinfo.h>
  37 #include <asm/processor.h>
  38 
  39 pgd_t *pgd_current;
  40 
  41 /*
  42  * paging_init() continues the virtual memory environment setup which
  43  * was begun by the code in arch/head.S.
  44  * The parameters are pointers to where to stick the starting and ending
  45  * addresses of available kernel virtual memory.
  46  */
  47 void __init paging_init(void)
  48 {
  49         unsigned long zones_size[MAX_NR_ZONES];
  50 
  51         memset(zones_size, 0, sizeof(zones_size));
  52 
  53         pagetable_init();
  54         pgd_current = swapper_pg_dir;
  55 
  56         zones_size[ZONE_NORMAL] = max_mapnr;
  57 
  58         /* pass the memory from the bootmem allocator to the main allocator */
  59         free_area_init(zones_size);
  60 
  61         flush_dcache_range((unsigned long)empty_zero_page,
  62                         (unsigned long)empty_zero_page + PAGE_SIZE);
  63 }
  64 
  65 void __init mem_init(void)
  66 {
  67         unsigned long end_mem   = memory_end; /* this must not include
  68                                                 kernel stack at top */
  69 
  70         pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
  71 
  72         end_mem &= PAGE_MASK;
  73         high_memory = __va(end_mem);
  74 
  75         /* this will put all memory onto the freelists */
  76         memblock_free_all();
  77         mem_init_print_info(NULL);
  78 }
  79 
  80 void __init mmu_init(void)
  81 {
  82         flush_tlb_all();
  83 }
  84 
  85 #define __page_aligned(order) __aligned(PAGE_SIZE << (order))
  86 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
  87 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
  88 static struct page *kuser_page[1];
  89 
  90 static int alloc_kuser_page(void)
  91 {
  92         extern char __kuser_helper_start[], __kuser_helper_end[];
  93         int kuser_sz = __kuser_helper_end - __kuser_helper_start;
  94         unsigned long vpage;
  95 
  96         vpage = get_zeroed_page(GFP_ATOMIC);
  97         if (!vpage)
  98                 return -ENOMEM;
  99 
 100         /* Copy kuser helpers */
 101         memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
 102 
 103         flush_icache_range(vpage, vpage + KUSER_SIZE);
 104         kuser_page[0] = virt_to_page(vpage);
 105 
 106         return 0;
 107 }
 108 arch_initcall(alloc_kuser_page);
 109 
 110 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 111 {
 112         struct mm_struct *mm = current->mm;
 113         int ret;
 114 
 115         down_write(&mm->mmap_sem);
 116 
 117         /* Map kuser helpers to user space address */
 118         ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
 119                                       VM_READ | VM_EXEC | VM_MAYREAD |
 120                                       VM_MAYEXEC, kuser_page);
 121 
 122         up_write(&mm->mmap_sem);
 123 
 124         return ret;
 125 }
 126 
 127 const char *arch_vma_name(struct vm_area_struct *vma)
 128 {
 129         return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
 130 }