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, int neighbor_fd)
  38 {
  39         long ret;
  40         struct module *owner = spufs_calls.owner;
  41         struct file *neighbor;
  42         int fput_needed;
  43
  44         ret = -ENOSYS;
  45         if (owner && try_module_get(owner)) {
  46                 if (flags & SPU_CREATE_AFFINITY_SPU) {
  47                         neighbor = fget_light(neighbor_fd, &fput_needed);
  48                         ret = -EBADF;
  49                         if (neighbor) {
  50                                 ret = spufs_calls.create_thread(name, flags,
  51                                                                 mode, neighbor);
  52                                 fput_light(neighbor, fput_needed);
  53                         }
  54                 }
  55                 else {
  56                         ret = spufs_calls.create_thread(name, flags,
  57                                                         mode, NULL);
  58                 }
  59                 module_put(owner);
  60         }
  61         return ret;
  62 }
  63
  64 asmlinkage long sys_spu_run(int fd, __u32 __user *unpc, __u32 __user *ustatus)
  65 {
  66         long ret;
  67         struct file *filp;
  68         int fput_needed;
  69         struct module *owner = spufs_calls.owner;
  70
  71         ret = -ENOSYS;
  72         if (owner && try_module_get(owner)) {
  73                 ret = -EBADF;
  74                 filp = fget_light(fd, &fput_needed);
  75                 if (filp) {
  76                         ret = spufs_calls.spu_run(filp, unpc, ustatus);
  77                         fput_light(filp, fput_needed);
  78                 }
  79                 module_put(owner);
  80         }
  81         return ret;
  82 }
  83
  84 int register_spu_syscalls(struct spufs_calls *calls)
  85 {
  86         if (spufs_calls.owner)
  87                 return -EBUSY;
  88
  89         spufs_calls.create_thread = calls->create_thread;
  90         spufs_calls.spu_run = calls->spu_run;
  91         smp_mb();
  92         spufs_calls.owner = calls->owner;
  93         return 0;
  94 }
  95 EXPORT_SYMBOL_GPL(register_spu_syscalls);
  96
  97 void unregister_spu_syscalls(struct spufs_calls *calls)
  98 {
  99         BUG_ON(spufs_calls.owner != calls->owner);
 100         spufs_calls.owner = NULL;
 101 }
 102 EXPORT_SYMBOL_GPL(unregister_spu_syscalls);