This patch adds a new file called 'mfc' to each spufs directory.
The file accepts DMA commands that are a subset of what would
be legal DMA commands for problem state register access. Upon
reading the file, a bitmask is returned with the completed
tag groups set.

The file is meant to be used from an abstraction in libspe
that is added by a different patch.

From the kernel perspective, this means a process can now
offload a memory copy from or into an SPE local store
without having to run code on the SPE itself.

The transfer will only be performed while the SPE is owned
by one thread that is waiting in the spu_run system call
and the data will be transferred into that thread's
address space, independent of which thread started the
transfer.
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

An SPU does not have a way to implement system calls
itself, but it can create intercepts to the kernel.

This patch uses the method defined by the JSRE interface
for C99 host library calls from an SPU to implement
Linux system calls. It uses the reserved SPU stop code
0x2104 for this, using the structure layout and syscall
numbers for ppc64-linux.

I'm still undecided wether it is better to have a list
of allowed syscalls or a list of forbidden syscalls,
since we can't allow an SPU to call all syscalls that
are defined for ppc64-linux.

This patch implements the easier choice of them, with a
blacklist that only prevents an SPU from calling anything
that interacts with its own execution, e.g fork, execve,
clone, vfork, exit, spu_run and spu_create and everything
that deals with signals.
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

These symbols are only used in the file that they are defined in,
so they should not be in the global namespace.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The SPE Book IV indicates that MFC DMA operations must be
suspended and restored on SPU context switch (in Step 8).

This patch adds that operation, which is missing from the
current spufs implementation.
Signed-off-by: NMasato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Acked-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.
Modified-by: NIngo Molnar <mingo@elte.hu>

(finished the conversion)
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For far, all SPU triggered interrupts always end up on
the first SMT thread, which is a bad solution.

This patch implements setting the affinity to the
CPU that was running last when entering execution on
an SPU. This should result in a significant reduction
in IPI calls and better cache locality for SPE thread
specific data.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

One local variable is missing an __iomem modifier,
in another place, we pass a completely unused argument
with a missing __user modifier.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

In a hypervisor based setup, direct access to the first
priviledged register space can typically not be allowed
to the kernel and has to be implemented through hypervisor
calls.

As suggested by Masato Noguchi, let's abstract the register
access trough a number of function calls. Since there is
currently no public specification of actual hypervisor
calls to implement this, I only provide a place that
makes it easier to hook into.

Cc: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Cc: Geoff Levand <geoff.levand@am.sony.com>
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The logic for sys_spu_run keeps growing and it does
not really belong into file.c any more since we
moved away from using regular file operations to our
own syscall.

No functional change in here.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

checking bits manually might not be synchonized with
the use of set_bit/clear_bit. Make sure we always use
the correct bitops by removing the unnecessary
identifiers.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

If creating one entry failed in spufs_fill_dir,
we never cleaned up the freshly created entries.
Fix this by calling the cleanup function on error.

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

If get_unused_fd failed in sys_spu_create, we never cleaned
up the created directory. Fix that by restructuring the
error path.

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

When spu_activate fails in spu_acquire_runnable, the
state must still be SPU_STATE_SAVED, we were
incorrectly setting it to SPU_STATE_RUNNABLE.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

During an earlier cleanup, we lost the serialization
of multiple spu_run calls performed on the same
spu_context. In order to get this back, introduce a
mutex in the spu_context that is held inside of spu_run.

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

Only checking for SPUFS_MAGIC is not reliable, because
it might not be unique in theory. Worse than that,
we accidentally allow spu_run to be performed on
any file in spufs, not just those returned from
spu_create as intended.

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

spu_forget will do mmput on the DMA address space,
which can lead to lots of other stuff getting triggered.
We better not hold a semaphore here that we might
need in the process.

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

We need to check for validity of owner under down_write,
down_read is not enough.

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

Output from hexdump with "%08x" depends on HOST platform's endian.
When building linux by cross toolchain, that difference makes errors.
Signed-off-by: NMasato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: NGeoff Levand <geoff.levand@am.sony.com>
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

One of my last patches contained a broken line
from splitting out some other changes, this
restores a working version.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Handling mailbox interrupts was broken in multiple respects,
the combination of which was hiding the bugs most of the time.

- The ibox interrupt mask was open initially even though there
  are no waiters on a newly created SPU.

- Acknowledging the mailbox interrupt did not work because
  it is level triggered and the mailbox data is never retrieved
  from inside the interrupt handler.

- The interrupt handler delivered interrupts with a disabled
  mask if another interrupt is triggered for the same class
  but a different mask.

- The poll function did not enable the interrupt if it had not
  been enabled, so we might run into the poll timeout if none of
  the other bugs saved us and no signal was delivered.

We probably still have a similar problem with blocking
read/write on mailbox files, but that will result in extra
wakeup in the worst case, not in incorrect behaviour.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch reduces lock complexity of SPU scheduler, particularly
for involuntary preemptive switches.  As a result the new code
does a better job of mapping the highest priority tasks to SPUs.

Lock complexity is reduced by using the system default workqueue
to perform involuntary saves.  In this way we avoid nasty lock
ordering problems that the previous code had.  A "minimum timeslice"
for SPU contexts is also introduced.  The intent here is to avoid
thrashing.

While the new scheduler does a better job at prioritization it
still does nothing for fairness.

From: Mark Nutter <mnutter@us.ibm.com>
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This patch makes it easier to preempt an SPU context by
having the scheduler hold ctx->state_sema for much shorter
periods of time.

As part of this restructuring, the control logic for the "run"
operation is moved from arch/ppc64/kernel/spu_base.c to
fs/spufs/file.c.  Of course the base retains "bottom half"
handlers for class{0,1} irqs.  The new run loop will re-acquire
an SPU if preempted.

From: Mark Nutter <mnutter@us.ibm.com>
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

spufs is rather noisy when debugging is enabled, this
turns off the messages for production use.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

With the new rules for reserved pages, the spufs now
needs working page reference counting.

I should probably look into converting to vm_insert_page,
but for now this patch makes spufs work again.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds a scheduler for SPUs to make it possible to use
more logical SPUs than physical ones are present in the
system.

Currently, there is no support for preempting a running
SPU thread, they have to leave the SPU by either triggering
an event on the SPU that causes it to return to the
owning thread or by sending a signal to it.

This patch also adds operations that enable accessing an SPU
in either runnable or saved state. We use an RW semaphore
to protect the state of the SPU from changing underneath
us, while we are holding it readable. In order to change
the state, it is acquired writeable and a context save
or restore is executed before downgrading the semaphore
to read-only.

From: Mark Nutter <mnutter@us.ibm.com>,
      Uli Weigand <Ulrich.Weigand@de.ibm.com>
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add the source code that is used to generate spu_save_dump.h and
spu_restore_dump.h. Since a full spu tool chain is needed to
generate these files, the default remains to use the shipped
versions in order to keep the number of tools for building the
kernel down.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds the code needed to perform a context switch from
spufs, following the recommended 76-step sequence.
Signed-off-by: NArnd Bergmann <arndb@de.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Add some infrastructure for saving and restoring the context of an
SPE. This patch creates a new structure that can hold the whole
state of a physical SPE in memory. It also contains code that
avoids races during the context switch and the binary code that
is loaded to the SPU in order to access its registers.

The actual PPE- and SPE-side context switch code are two separate
patches.
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>