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 #include <linux/execmem.h>
  30
  31 #include <asm/setup.h>
  32 #include <asm/page.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 max_zone_pfn[MAX_NR_ZONES] = { 0 };
  50
  51         pagetable_init();
  52         pgd_current = swapper_pg_dir;
  53
  54         max_zone_pfn[ZONE_NORMAL] = max_mapnr;
  55
  56         /* pass the memory from the bootmem allocator to the main allocator */
  57         free_area_init(max_zone_pfn);
  58
  59         flush_dcache_range((unsigned long)empty_zero_page,
  60                         (unsigned long)empty_zero_page + PAGE_SIZE);
  61 }
  62
  63 void __init mem_init(void)
  64 {
  65         unsigned long end_mem   = memory_end; /* this must not include
  66                                                 kernel stack at top */
  67
  68         pr_debug("mem_init: start=%lx, end=%lx\n", memory_start, memory_end);
  69
  70         end_mem &= PAGE_MASK;
  71         high_memory = __va(end_mem);
  72
  73         /* this will put all memory onto the freelists */
  74         memblock_free_all();
  75 }
  76
  77 void __init mmu_init(void)
  78 {
  79         flush_tlb_all();
  80 }
  81
  82 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  83 pte_t invalid_pte_table[PTRS_PER_PTE] __aligned(PAGE_SIZE);
  84 static struct page *kuser_page[1];
  85 static struct vm_special_mapping vdso_mapping = {
  86         .name = "[vdso]",
  87         .pages = kuser_page,
  88 };
  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         struct vm_area_struct *vma;
 114
 115         mmap_write_lock(mm);
 116
 117         /* Map kuser helpers to user space address */
 118         vma = _install_special_mapping(mm, KUSER_BASE, KUSER_SIZE,
 119                                       VM_READ | VM_EXEC | VM_MAYREAD |
 120                                       VM_MAYEXEC, &vdso_mapping);
 121
 122         mmap_write_unlock(mm);
 123
 124         return IS_ERR(vma) ? PTR_ERR(vma) : 0;
 125 }
 126
 127 const char *arch_vma_name(struct vm_area_struct *vma)
 128 {
 129         return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
 130 }
 131
 132 static const pgprot_t protection_map[16] = {
 133         [VM_NONE]                                       = MKP(0, 0, 0),
 134         [VM_READ]                                       = MKP(0, 0, 1),
 135         [VM_WRITE]                                      = MKP(0, 0, 0),
 136         [VM_WRITE | VM_READ]                            = MKP(0, 0, 1),
 137         [VM_EXEC]                                       = MKP(1, 0, 0),
 138         [VM_EXEC | VM_READ]                             = MKP(1, 0, 1),
 139         [VM_EXEC | VM_WRITE]                            = MKP(1, 0, 0),
 140         [VM_EXEC | VM_WRITE | VM_READ]                  = MKP(1, 0, 1),
 141         [VM_SHARED]                                     = MKP(0, 0, 0),
 142         [VM_SHARED | VM_READ]                           = MKP(0, 0, 1),
 143         [VM_SHARED | VM_WRITE]                          = MKP(0, 1, 0),
 144         [VM_SHARED | VM_WRITE | VM_READ]                = MKP(0, 1, 1),
 145         [VM_SHARED | VM_EXEC]                           = MKP(1, 0, 0),
 146         [VM_SHARED | VM_EXEC | VM_READ]                 = MKP(1, 0, 1),
 147         [VM_SHARED | VM_EXEC | VM_WRITE]                = MKP(1, 1, 0),
 148         [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = MKP(1, 1, 1)
 149 };
 150 DECLARE_VM_GET_PAGE_PROT
 151
 152 #ifdef CONFIG_EXECMEM
 153 static struct execmem_info execmem_info __ro_after_init;
 154
 155 struct execmem_info __init *execmem_arch_setup(void)
 156 {
 157         execmem_info = (struct execmem_info){
 158                 .ranges = {
 159                         [EXECMEM_DEFAULT] = {
 160                                 .start  = MODULES_VADDR,
 161                                 .end    = MODULES_END,
 162                                 .pgprot = PAGE_KERNEL_EXEC,
 163                                 .alignment = 1,
 164                         },
 165                 },
 166         };
 167
 168         return &execmem_info;
 169 }
 170 #endif /* CONFIG_EXECMEM */