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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Acked-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

At present, a built-in spufs will not use the spufs_calls callbacks, but
directly call sys_spu_create.  This saves us an indirect branch, but
means we have duplicated functions - one for CONFIG_SPU_FS=y and one for
=m.

This change unifies the spufs syscall path, and provides access to the
spufs_calls structure through a get/put pair.  At present, the only user
of the spufs_calls structure is spu_syscalls.c, but this will facilitate
adding the coredump calls later.

Everyone likes numbers, right?  Here's a before/after comparison with
CONFIG_SPU_FS=y, doing spu_create(); close(); 64k times.

Before:
	[jk@cell ~]$ time ./spu_create
	performing 65536 spu_create calls

	real    0m24.075s
	user    0m0.146s
	sys     0m23.925s

After:
	[jk@cell ~]$ time ./spu_create
	performing 65536 spu_create calls

	real    0m24.777s
	user    0m0.141s
	sys     0m24.631s

So, we're adding around 11us per syscall, at the benefit of having
only one syscall path.
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

At present, spu_create with an invalid neighbo(u)r will return -ENOSYS,
not -EBADF, but only when spufs.o is built as a module.

This change adds the appropriate errno, making the behaviour the same
as the built-in case.
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Acked-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch adds support for additional flags at spu_create, which relate
to the establishment of affinity between contexts and contexts to memory.
A fourth, optional, parameter is supported. This parameter represent
a affinity neighbor of the context being created, and is used when defining
SPU-SPU affinity.
Affinity is represented as a doubly linked list of spu_contexts.
Signed-off-by: NAndre Detsch <adetsch@br.ibm.com>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

One of the two users of spufs_calls.owner still has a race
when calling try_module_get while the module is removed.
This makes it use the correct instance of owner.

Noticed by Milton Miller.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

try_module_get returns true when NULL arguments, so
we first need to check if there is a module loaded before
getting the reference count.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This is the current version of the spu file system, used
for driving SPEs on the Cell Broadband Engine.

This release is almost identical to the version for the
2.6.14 kernel posted earlier, which is available as part
of the Cell BE Linux distribution from
http://www.bsc.es/projects/deepcomputing/linuxoncell/.

The first patch provides all the interfaces for running
spu application, but does not have any support for
debugging SPU tasks or for scheduling. Both these
functionalities are added in the subsequent patches.

See Documentation/filesystems/spufs.txt on how to use
spufs.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>