LXR linux/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
  30syscall_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
  39asmlinkage 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
  50asmlinkage 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
  57unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  58                unsigned long len, unsigned long pgoff, unsigned long flags)
  59{
  60        struct vm_area_struct *vmm;
  61
  62        if (flags & MAP_FIXED) {
  63                /* We do not accept a shared mapping if it would violate
  64                 * cache aliasing constraints.
  65                 */
  66                if ((flags & MAP_SHARED) &&
  67                                ((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
  68                        return -EINVAL;
  69                return addr;
  70        }
  71
  72        if (len > TASK_SIZE)
  73                return -ENOMEM;
  74        if (!addr)
  75                addr = TASK_UNMAPPED_BASE;
  76
  77        if (flags & MAP_SHARED)
  78                addr = COLOUR_ALIGN(addr, pgoff);
  79        else
  80                addr = PAGE_ALIGN(addr);
  81
  82        for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
  83                /* At this point:  (!vmm || addr < vmm->vm_end). */
  84                if (TASK_SIZE - len < addr)
  85                        return -ENOMEM;
  86                if (!vmm || addr + len <= vm_start_gap(vmm))
  87                        return addr;
  88                addr = vmm->vm_end;
  89                if (flags & MAP_SHARED)
  90                        addr = COLOUR_ALIGN(addr, pgoff);
  91        }
  92}
  93#endif
  94