1 files changed, 123 insertions, 33 deletions

diff --git a/arch/powerpc/platforms/cell/spu_syscalls.c b/arch/powerpc/platforms/cell/spu_syscalls.c
index 261b507a901..5e6e0bad6db 100644
--- a/arch/powerpc/platforms/cell/spu_syscalls.c
+++ b/arch/powerpc/platforms/cell/spu_syscalls.c
@@ -2,6 +2,7 @@
  * 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>
  *
@@ -20,69 +21,158 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 #include <linux/file.h>
+#include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/syscalls.h>
+#include <linux/rcupdate.h>
+#include <linux/binfmts.h>
 
 #include <asm/spu.h>
 
-struct spufs_calls spufs_calls = {
-	.owner = NULL,
-};
+/* protected by rcu */
+static struct spufs_calls *spufs_calls;
 
-/* These stub syscalls are needed to have the actual implementation
- * within a loadable module. When spufs is built into the kernel,
- * this file is not used and the syscalls directly enter the fs code */
+#ifdef CONFIG_SPU_FS_MODULE
 
-asmlinkage long sys_spu_create(const char __user *name,
-		unsigned int flags, mode_t mode)
+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 */
+
+SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
+	umode_t, mode, int, neighbor_fd)
 {
 	long ret;
-	struct module *owner = spufs_calls.owner;
+	struct spufs_calls *calls;
 
-	ret = -ENOSYS;
-	if (owner && try_module_get(owner)) {
-		ret = spufs_calls.create_thread(name, flags, mode);
-		module_put(owner);
-	}
+	calls = spufs_calls_get();
+	if (!calls)
+		return -ENOSYS;
+
+	if (flags & SPU_CREATE_AFFINITY_SPU) {
+		struct fd neighbor = fdget(neighbor_fd);
+		ret = -EBADF;
+		if (neighbor.file) {
+			ret = calls->create_thread(name, flags, mode, neighbor.file);
+			fdput(neighbor);
+		}
+	} 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 module *owner = spufs_calls.owner;
+	struct fd arg;
+	struct spufs_calls *calls;
 
-	ret = -ENOSYS;
-	if (owner && try_module_get(owner)) {
-		ret = -EBADF;
-		filp = fget_light(fd, &fput_needed);
-		if (filp) {
-			ret = spufs_calls.spu_run(filp, unpc, ustatus);
-			fput_light(filp, fput_needed);
-		}
-		module_put(owner);
+	calls = spufs_calls_get();
+	if (!calls)
+		return -ENOSYS;
+
+	ret = -EBADF;
+	arg = fdget(fd);
+	if (arg.file) {
+		ret = calls->spu_run(arg.file, unpc, ustatus);
+		fdput(arg);
 	}
+
+	spufs_calls_put(calls);
+	return ret;
+}
+
+#ifdef CONFIG_COREDUMP
+int elf_coredump_extra_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;
 }
 
+int elf_coredump_extra_notes_write(struct coredump_params *cprm)
+{
+	struct spufs_calls *calls;
+	int ret;
+
+	calls = spufs_calls_get();
+	if (!calls)
+		return 0;
+
+	ret = calls->coredump_extra_notes_write(cprm);
+
+	spufs_calls_put(calls);
+
+	return ret;
+}
+#endif
+
+void notify_spus_active(void)
+{
+	struct spufs_calls *calls;
+
+	calls = spufs_calls_get();
+	if (!calls)
+		return;
+
+	calls->notify_spus_active();
+	spufs_calls_put(calls);
+
+	return;
+}
+
 int register_spu_syscalls(struct spufs_calls *calls)
 {
-	if (spufs_calls.owner)
+	if (spufs_calls)
 		return -EBUSY;
 
-	spufs_calls.create_thread = calls->create_thread;
-	spufs_calls.spu_run = calls->spu_run;
-	smp_mb();
-	spufs_calls.owner = calls->owner;
+	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);
-	spufs_calls.owner = NULL;
+	BUG_ON(spufs_calls->owner != calls->owner);
+	RCU_INIT_POINTER(spufs_calls, NULL);
+	synchronize_rcu();
 }
 EXPORT_SYMBOL_GPL(unregister_spu_syscalls);