arch/nios2/kernel/sys_nios2.c

   1 /*
   2  * Copyright (C) 2013 Altera Corporation
   3  * Copyright (C) 2011-2012 Tobias Klauser <tklauser@distanz.ch>
   4  * Copyright (C) 2004 Microtronix Datacom Ltd.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #include <linux/export.h>
  12 #include <linux/file.h>
  13 #include <linux/fs.h>
  14 #include <linux/slab.h>
  15 #include <linux/syscalls.h>
  16
  17 #include <asm/cacheflush.h>
  18 #include <asm/traps.h>
  19
  20 /* sys_cacheflush -- flush the processor cache. */
  21 asmlinkage int sys_cacheflush(unsigned long addr, unsigned long len,
  22                                 unsigned int op)
  23 {
  24         struct vm_area_struct *vma;
  25         struct mm_struct *mm = current->mm;
  26
  27         if (len == 0)
  28                 return 0;
  29
  30         /* We only support op 0 now, return error if op is non-zero.*/
  31         if (op)
  32                 return -EINVAL;
  33
  34         /* Check for overflow */
  35         if (addr + len < addr)
  36                 return -EFAULT;
  37
  38         if (mmap_read_lock_killable(mm))
  39                 return -EINTR;
  40
  41         /*
  42          * Verify that the specified address region actually belongs
  43          * to this process.
  44          */
  45         vma = find_vma(mm, addr);
  46         if (vma == NULL || addr < vma->vm_start || addr + len > vma->vm_end) {
  47                 mmap_read_unlock(mm);
  48                 return -EFAULT;
  49         }
  50
  51         flush_cache_range(vma, addr, addr + len);
  52
  53         mmap_read_unlock(mm);
  54         return 0;
  55 }
  56
  57 asmlinkage int sys_getpagesize(void)
  58 {
  59         return PAGE_SIZE;
  60 }