arch/powerpc/platforms/cell/spu_syscalls.c

   1 /*
   2  * SPU file system -- system call stubs
   3  *
   4  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   5  *
   6  * Author: Arnd Bergmann <arndb@de.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  */
  22 #include <linux/file.h>
  23 #include <linux/module.h>
  24 #include <linux/syscalls.h>
  25
  26 #include <asm/spu.h>
  27
  28 struct spufs_calls spufs_calls = {
  29         .owner = NULL,
  30 };
  31
  32 /* These stub syscalls are needed to have the actual implementation
  33  * within a loadable module. When spufs is built into the kernel,
  34  * this file is not used and the syscalls directly enter the fs code */
  35
  36 asmlinkage long sys_spu_create(const char __user *name,
  37                 unsigned int flags, mode_t mode)
  38 {
  39         long ret;
  40         struct module *owner = spufs_calls.owner;
  41
  42         ret = -ENOSYS;
  43         if (owner && try_module_get(owner)) {
  44                 ret = spufs_calls.create_thread(name, flags, mode);
  45                 module_put(owner);
  46         }
  47         return ret;
  48 }
  49
  50 asmlinkage long sys_spu_run(int fd, __u32 __user *unpc, __u32 __user *ustatus)
  51 {
  52         long ret;
  53         struct file *filp;
  54         int fput_needed;
  55         struct module *owner = spufs_calls.owner;
  56
  57         ret = -ENOSYS;
  58         if (owner && try_module_get(owner)) {
  59                 ret = -EBADF;
  60                 filp = fget_light(fd, &fput_needed);
  61                 if (filp) {
  62                         ret = spufs_calls.spu_run(filp, unpc, ustatus);
  63                         fput_light(filp, fput_needed);
  64                 }
  65                 module_put(owner);
  66         }
  67         return ret;
  68 }
  69
  70 int register_spu_syscalls(struct spufs_calls *calls)
  71 {
  72         if (spufs_calls.owner)
  73                 return -EBUSY;
  74
  75         spufs_calls.create_thread = calls->create_thread;
  76         spufs_calls.spu_run = calls->spu_run;
  77         smp_mb();
  78         spufs_calls.owner = calls->owner;
  79         return 0;
  80 }
  81 EXPORT_SYMBOL_GPL(register_spu_syscalls);
  82
  83 void unregister_spu_syscalls(struct spufs_calls *calls)
  84 {
  85         BUG_ON(spufs_calls.owner != calls->owner);
  86         spufs_calls.owner = NULL;
  87 }
  88 EXPORT_SYMBOL_GPL(unregister_spu_syscalls);