linux_dsm_epyc7002/arch/powerpc/platforms/cell/spu_syscalls.c
Michael Ellerman 48cad41f7e [POWERPC] spufs: Combine spufs_coredump_calls with spufs_calls
Because spufs might be built as a module, we can't have other parts of the
kernel calling directly into it, we need stub routines that check first if the
module is loaded.

Currently we have two structures which hold callbacks for these stubs, the
syscalls are in spufs_calls and the coredump calls are in spufs_coredump_calls.
In both cases the logic for registering/unregistering is essentially the same,
so we can simplify things by combining the two.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-19 15:12:19 +10:00

161 lines
3.5 KiB
C

/*
* SPU file system -- system call stubs
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
* (C) Copyright 2006-2007, IBM Corporation
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/file.h>
#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/rcupdate.h>
#include <asm/spu.h>
/* protected by rcu */
static struct spufs_calls *spufs_calls;
#ifdef CONFIG_SPU_FS_MODULE
static inline struct spufs_calls *spufs_calls_get(void)
{
struct spufs_calls *calls = NULL;
rcu_read_lock();
calls = rcu_dereference(spufs_calls);
if (calls && !try_module_get(calls->owner))
calls = NULL;
rcu_read_unlock();
return calls;
}
static inline void spufs_calls_put(struct spufs_calls *calls)
{
BUG_ON(calls != spufs_calls);
/* we don't need to rcu this, as we hold a reference to the module */
module_put(spufs_calls->owner);
}
#else /* !defined CONFIG_SPU_FS_MODULE */
static inline struct spufs_calls *spufs_calls_get(void)
{
return spufs_calls;
}
static inline void spufs_calls_put(struct spufs_calls *calls) { }
#endif /* CONFIG_SPU_FS_MODULE */
asmlinkage long sys_spu_create(const char __user *name,
unsigned int flags, mode_t mode, int neighbor_fd)
{
long ret;
struct file *neighbor;
int fput_needed;
struct spufs_calls *calls;
calls = spufs_calls_get();
if (!calls)
return -ENOSYS;
if (flags & SPU_CREATE_AFFINITY_SPU) {
ret = -EBADF;
neighbor = fget_light(neighbor_fd, &fput_needed);
if (neighbor) {
ret = calls->create_thread(name, flags, mode, neighbor);
fput_light(neighbor, fput_needed);
}
} else
ret = calls->create_thread(name, flags, mode, NULL);
spufs_calls_put(calls);
return ret;
}
asmlinkage long sys_spu_run(int fd, __u32 __user *unpc, __u32 __user *ustatus)
{
long ret;
struct file *filp;
int fput_needed;
struct spufs_calls *calls;
calls = spufs_calls_get();
if (!calls)
return -ENOSYS;
ret = -EBADF;
filp = fget_light(fd, &fput_needed);
if (filp) {
ret = calls->spu_run(filp, unpc, ustatus);
fput_light(filp, fput_needed);
}
spufs_calls_put(calls);
return ret;
}
int arch_notes_size(void)
{
struct spufs_calls *calls;
int ret;
calls = spufs_calls_get();
if (!calls)
return 0;
ret = calls->coredump_extra_notes_size();
spufs_calls_put(calls);
return ret;
}
void arch_write_notes(struct file *file)
{
struct spufs_calls *calls;
calls = spufs_calls_get();
if (!calls)
return;
calls->coredump_extra_notes_write(file);
spufs_calls_put(calls);
}
int register_spu_syscalls(struct spufs_calls *calls)
{
if (spufs_calls)
return -EBUSY;
rcu_assign_pointer(spufs_calls, calls);
return 0;
}
EXPORT_SYMBOL_GPL(register_spu_syscalls);
void unregister_spu_syscalls(struct spufs_calls *calls)
{
BUG_ON(spufs_calls->owner != calls->owner);
rcu_assign_pointer(spufs_calls, NULL);
synchronize_rcu();
}
EXPORT_SYMBOL_GPL(unregister_spu_syscalls);