There is a delay in the transition to the stopped state for class 2
interrupts. In some cases, the controlling thread detects the state of
the spu as running, and goes back to sleep resulting in a hung
application as the event is missed.

This change detects the stop condition and re-generates the wakeup event
after a context save.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Time slicing can occur at the same time as spu exception handling
resulting in the wakeup of the wrong thread.

This change uses the the spu's register_lock to enforce synchronization
between bind/unbind and spu exception handling so that they are
mutually exclusive.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

According to the CBEA, the SPU dsisr is not updated for class 0
exceptions.

spu_stopped() is testing the dsisr that was passed to it from the class
0 exception handler, so we return a false positive here.

This patch cleans up the interrupt handler and erroneous tests in
spu_stopped. It also removes the fields from the csa since it is not
needed to process class 0 events.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

If the spu is stopping (ie, the SPU_STATUS_RUNNING bit is still set),
re-read the register to get the final stopped value.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix following warnings:
WARNING: arch/powerpc/platforms/cell/built-in.o(.devinit.text+0x9c): Section mismatch in reference from the function .cell_setup_phb() to the function .init.text:.iowa_register_bus()
WARNING: arch/powerpc/platforms/cell/built-in.o(.devinit.text+0xa4): Section mismatch in reference from the function .cell_setup_phb() to the function .init.text:.io_workaround_init()

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: Paul Mackerras <paulus@samba.org>

With CONFIG_VIRT_CPU_ACCOUNTING disabled, I got the following error:

linux-2.6/arch/powerpc/platforms/cell/spufs/file.c: In function 'spu_switch_log_notify':
linux-2.6/arch/powerpc/platforms/cell/spufs/file.c:2542: error: implicit declaration of function 'get_tb'
make[4]: *** [arch/powerpc/platforms/cell/spufs/file.o] Error 1

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Paul Mackerras <paulus@samba.org>

If victim (not ctx) is in spu_run, add victim to rq.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

We need to acquire the parent i_mutex with I_MUTEX_PARENT to keep
lockdep happy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

We should not requeue the victim context in find_victim if the owner is
not in spu_run. It's first not needed because leaving the context on
the spu is an optimization and second is harmful because it means the
owner could re-enter spu_run when the context is on the runqueue and
trip the BUG_ON in __spu_update_sched_info.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Creating a spufs context or gand using spu_create should send an inotify
event so that things like performance monitors have an easy way to find
out about newly created contexts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Currently, page fault handlers don't issue a mfc restart if the context
switch pending flag is set, which can leave us with a hanging DMA after
a context restore.

This patch introduces fault pending flag that is set by the fault
handler and read by the context switch code, so that the latter can add
the restart bit at the right spot, after it has successfuly saved the
state of the mfc control register.

Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

SPU class 0 & 1 exceptions may occur in parallel, so we may end up
overwriting csa.dsisr.

This change adds dedicated fields for each class to the spu and the spu
context so that fault data is not overwritten.

Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Currently, we re-route SPU interrupts to the current cpu, which may be
on a remote node. In the case of time slicing, all spu interrupts will
end up routed to the same cpu, where the spusched_tick occurs.

This change routes mfc interrupts to the cpu where the controlling
thread last ran, provided that cpu is on the same node as the spu
(otherwise don't reroute interrupts).

This should improve performance and provide a more predictable
environment for processing spu exceptions. In the past we have seen
concurrent delivery of spu exceptions to two cpus. This eliminates that
concern.

Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

synchronize_irq() provides the serialization for
SPU_CONTEXT_SWITCH_PENDING which is read with a simple load. This
routine guarantees that the relevant interrupt handlers are not running,
so that the next time they do run they will see the update
memory value.

This must be done correctly so that exception handling code does not
restart the mfc in the middle of a context switch while we are trying
to atomically stop it and save state.

Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

There's currently no way to tell if spu_process_callback has
returned with the state mutex held, as -EINTR may be returned
by either the syscall or the spu_acquire fail case.

Instead, just do a non-interruptible mutex_lock here.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Currently, we update the SPU master run control bit (ie,
spu_enable_spu) in spufs_run_spu before we grab the context mutex. This
can result in races with other processes accessing this context's
resources.

This change moves the spu_enable_spu to after we have acquired the
context lock.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

We currently have two issues with the MFC save code:

 * save_mfc_decr doesn't handle a transition of 1 -> 0 of the Ds bit
 * The Q bit may be stale in the CSA

This change fixes the first issue by clearing the relevant bits from
the MFC_CNTL value in the CSA before or-ing in the updated status.
Also, we add the Q bit to the updated status.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Currently, we can introduce invalid entries into the MFC queues:

1) context starts a DMA

2) context gets scheduled out during a DMA
  - kernel saves MFC queue to CSA
  - kernel saves 0x0 in csa->mfc_control_RW

3) context gets scheduled in
  - csa->mfc_control[Q] ('queues empty') isn't set, so DMA queues are
    restored from the CSA

4) context's DMA is completed

5) context gets scheduled out again, no DMA occuring this time
  - kernel sees that MFC_CNTL[Q] ('queues empty') is set, so doesn't
    touch saved queue data in CSA
  - kernel saves 0x0 in csa->mfc_control_RW

6) context gets scheduled in
  - csa->mfc_control[Q] ('queues empty') isn't set (we saved is as 0!),
    so DMA queues are restored from the CSA

In this last restore, we've restored the queue status from step 2,
which are now invalid.

This change makes save_mfc_cntl() closer to the save/restore sequence,
as specified in the CBE handbook.

With changes from Luke Browning.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

When we issue a MFC purge request, we may inadvertantly clear the
suspended status.

This change adds the MFC_CNTL_SUSPEND_MASK when we issue a purge
request, so that the suspend bit is masked out.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

We may currently lose interrupts during SPE context switch, as we alter
the INT_Route register. Because the IIC uses a per-thread priority
status, changing the interrupt routing to a different thread means that
the IRQ is no longer masked by the priority status, so we end up with
two fasteoi IRQ handlers executing for the one irq_desc. The fasteoi
handler doesn't handle multiple IRQs, so drops the second one.

Fix this by using our own flow handler. This is based on
handle_edge_irq, but issues an eoi after IRQs are handled, and doesn't
do any mask/unmasking.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Initial splitoff of the low-level stuff; taken to fdtable.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

The sputrace module contained a trace entry for spu_acquire_saved, but
this marker was not placed anywhere. Fix this by adding a marker to the
routine.

Signed-off-by: Julio M. Merino Vidal <jmerino@ac.upc.edu>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Fix a typo in the marker for the find_victim function, which prevented
it from being traced. It previously read find_vitim.

Signed-off-by: Julio M. Merino Vidal <jmerino@ac.upc.edu>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

The sputrace module contained a reference to a marker for
destroy_spu_context, but this marker did not appear in the code. Fix
this by adding a marker in the function.

Signed-off-by: Julio M. Merino Vidal <jmerino@ac.upc.edu>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

The markers facility defines the marker parameters to be of the form
'name %format'. Add parameter names to sputrace, to specify the context
and %spu paramerters,  instead of just specifying the '%format' part.

Signed-off-by: Julio M. Merino Vidal <jmerino@ac.upc.edu>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

There are userspace instrumentation tools that need to monitor spu
context switches. This patch adds a new file called 'switch_log' to
each spufs context directory that can be used to monitor the context
switches.

Context switch in/out and exit from spu_run are monitored after the
file was first opened and can be read from it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This adds support for PCI Express port on Celleb.  I/O space of this
PCI Express port is not mapped in memory space.  So we use the
io-workaround mechanism to make accesses indirect.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This moves miscellaneous files for Beat into platforms/cell/.
All files in this patch are used by celleb-beat only.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This moves SPU support code on Beat into platforms/cell/.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This moves files for mmu and iommu on Beat into platforms/cell/.
All files in this patch are used by celleb-beat only.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This moves files for Beat hvcall interfaces into platforms/cell/.
All files in this patch are used by celleb-beat only.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This moves the SCC (Super Companion Chip) related code for celleb
into platforms/cell/.
All files in this patch are used by celleb-beat and celleb-native
commonly.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This moves the base code for celleb support into platforms/cell/.
All files in this patch are used by celleb-beat and celleb-native
commonly.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Now, we can use generic io-workarounds mechanism and the workaround
code for spider-pci. This changes Celleb PCI code to use spider-pci
code.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This splits cell io-workaround code into spider-pci dependent code and
a generic part, and also moves io-workarounds initialization into
cell_setup_phb.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Replace two open-coded occurences of the of_get_next_parent() logic.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>