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 <asm/unistd.h>
  21 #include <linux/linkage.h>
  22 #include <linux/stringify.h>
  23 #include <linux/errno.h>
  24 #include <linux/syscalls.h>
  25 #include <linux/file.h>
  26 #include <linux/fs.h>
  27 #include <linux/mman.h>
  28 #include <linux/sched/mm.h>
  29 #include <linux/shm.h>
  30
  31 typedef void (*syscall_t)(void);
  32
  33 syscall_t sys_call_table[__NR_syscall_count] /* FIXME __cacheline_aligned */= {
  34         [0 ... __NR_syscall_count - 1] = (syscall_t)&sys_ni_syscall,
  35
  36 #define __SYSCALL(nr,symbol,nargs) [ nr ] = (syscall_t)symbol,
  37 #include <uapi/asm/unistd.h>
  38 };
  39
  40 #define COLOUR_ALIGN(addr, pgoff) \
  41         ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
  42          (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
  43
  44 asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
  45 {
  46         unsigned long ret;
  47         long err;
  48
  49         err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
  50         if (err)
  51                 return err;
  52         return (long)ret;
  53 }
  54
  55 asmlinkage long xtensa_fadvise64_64(int fd, int advice,
  56                 unsigned long long offset, unsigned long long len)
  57 {
  58         return sys_fadvise64_64(fd, offset, len, advice);
  59 }
  60
  61 #ifdef CONFIG_MMU
  62 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  63                 unsigned long len, unsigned long pgoff, unsigned long flags)
  64 {
  65         struct vm_area_struct *vmm;
  66
  67         if (flags & MAP_FIXED) {
  68                 /* We do not accept a shared mapping if it would violate
  69                  * cache aliasing constraints.
  70                  */
  71                 if ((flags & MAP_SHARED) &&
  72                                 ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
  73                         return -EINVAL;
  74                 return addr;
  75         }
  76
  77         if (len > TASK_SIZE)
  78                 return -ENOMEM;
  79         if (!addr)
  80                 addr = TASK_UNMAPPED_BASE;
  81
  82         if (flags & MAP_SHARED)
  83                 addr = COLOUR_ALIGN(addr, pgoff);
  84         else
  85                 addr = PAGE_ALIGN(addr);
  86
  87         for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
  88                 /* At this point:  (!vmm || addr < vmm->vm_end). */
  89                 if (TASK_SIZE - len < addr)
  90                         return -ENOMEM;
  91                 if (!vmm || addr + len <= vm_start_gap(vmm))
  92                         return addr;
  93                 addr = vmm->vm_end;
  94                 if (flags & MAP_SHARED)
  95                         addr = COLOUR_ALIGN(addr, pgoff);
  96         }
  97 }
  98 #endif