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
  38 pgd_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  */
  46 void __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
  62 void __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         mem_init_print_info(NULL);
  75 }
  76
  77 void __init mmu_init(void)
  78 {
  79         flush_tlb_all();
  80 }
  81
  82 #define __page_aligned(order) __aligned(PAGE_SIZE << (order))
  83 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
  84 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);
  85 static struct page *kuser_page[1];
  86
  87 static int alloc_kuser_page(void)
  88 {
  89         extern char __kuser_helper_start[], __kuser_helper_end[];
  90         int kuser_sz = __kuser_helper_end - __kuser_helper_start;
  91         unsigned long vpage;
  92
  93         vpage = get_zeroed_page(GFP_ATOMIC);
  94         if (!vpage)
  95                 return -ENOMEM;
  96
  97         /* Copy kuser helpers */
  98         memcpy((void *)vpage, __kuser_helper_start, kuser_sz);
  99
 100         flush_icache_range(vpage, vpage + KUSER_SIZE);
 101         kuser_page[0] = virt_to_page(vpage);
 102
 103         return 0;
 104 }
 105 arch_initcall(alloc_kuser_page);
 106
 107 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 108 {
 109         struct mm_struct *mm = current->mm;
 110         int ret;
 111
 112         mmap_write_lock(mm);
 113
 114         /* Map kuser helpers to user space address */
 115         ret = install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
 116                                       VM_READ | VM_EXEC | VM_MAYREAD |
 117                                       VM_MAYEXEC, kuser_page);
 118
 119         mmap_write_unlock(mm);
 120
 121         return ret;
 122 }
 123
 124 const char *arch_vma_name(struct vm_area_struct *vma)
 125 {
 126         return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
 127 }