arch/xtensa/kernel/syscall.c

   1 /*
   2  * arch/xtensa/kernel/syscall.c
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 2001 - 2005 Tensilica Inc.
   9  * Copyright (C) 2000 Silicon Graphics, Inc.
  10  * Copyright (C) 1995 - 2000 by Ralf Baechle
  11  *
  12  * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
  13  * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
  14  * Chris Zankel <chris@zankel.net>
  15  * Kevin Chea
  16  *
  17  */
  18 #include <linux/uaccess.h>
  19 #include <asm/syscall.h>
  20 #include <linux/linkage.h>
  21 #include <linux/stringify.h>
  22 #include <linux/errno.h>
  23 #include <linux/syscalls.h>
  24 #include <linux/file.h>
  25 #include <linux/fs.h>
  26 #include <linux/mman.h>
  27 #include <linux/sched/mm.h>
  28 #include <linux/shm.h>
  29
  30 syscall_t sys_call_table[] /* FIXME __cacheline_aligned */= {
  31 #define __SYSCALL(nr, entry)    (syscall_t)entry,
  32 #include <asm/syscall_table.h>
  33 };
  34
  35 #define COLOUR_ALIGN(addr, pgoff) \
  36         ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
  37          (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
  38
  39 asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
  40 {
  41         unsigned long ret;
  42         long err;
  43
  44         err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
  45         if (err)
  46                 return err;
  47         return (long)ret;
  48 }
  49
  50 asmlinkage long xtensa_fadvise64_64(int fd, int advice,
  51                 unsigned long long offset, unsigned long long len)
  52 {
  53         return ksys_fadvise64_64(fd, offset, len, advice);
  54 }
  55
  56 #ifdef CONFIG_MMU
  57 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  58                 unsigned long len, unsigned long pgoff, unsigned long flags,
  59                 vm_flags_t vm_flags)
  60 {
  61         struct vm_area_struct *vmm;
  62         struct vma_iterator vmi;
  63
  64         if (flags & MAP_FIXED) {
  65                 /* We do not accept a shared mapping if it would violate
  66                  * cache aliasing constraints.
  67                  */
  68                 if ((flags & MAP_SHARED) &&
  69                                 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
  70                         return -EINVAL;
  71                 return addr;
  72         }
  73
  74         if (len > TASK_SIZE)
  75                 return -ENOMEM;
  76         if (!addr)
  77                 addr = TASK_UNMAPPED_BASE;
  78
  79         if (flags & MAP_SHARED)
  80                 addr = COLOUR_ALIGN(addr, pgoff);
  81         else
  82                 addr = PAGE_ALIGN(addr);
  83
  84         vma_iter_init(&vmi, current->mm, addr);
  85         for_each_vma(vmi, vmm) {
  86                 /* At this point:  (addr < vmm->vm_end). */
  87                 if (addr + len <= vm_start_gap(vmm))
  88                         break;
  89
  90                 addr = vmm->vm_end;
  91                 if (flags & MAP_SHARED)
  92                         addr = COLOUR_ALIGN(addr, pgoff);
  93         }
  94
  95         if (TASK_SIZE - len < addr)
  96                 return -ENOMEM;
  97
  98         return addr;
  99 }
 100 #endif