Currently, the kernel may fail to restart a SPE context which
has stopped and been swapped out.
This changes spu_backing_runcntl_write to emulate the real
SPU_Status register exactly. When the SPU Run Control register
is written with SPU_RunCntl[Run] set to '1', the physical SPU
automatically sets SPU_Status[R] and clears SPU_Status[CISHP].
Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This fixes the behavior of spufs when a spu tries a DMA operation
based on a wrong / unavailable address.
Instead of just generating a SIGBUS signal, spufs now
generates a SIGSEGV signal and restarts the problematic DMA operation
after the execution of the application's signal handler. This allows
applications to employ user-level paging systems.
Although the restart_dma function is called before the application's
signal handler, the operation is not actually performed at this time,
since the spu context is already stopped. The operation only takes
place when spu_run is restarted (which happens automatically).
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a few #defines for the class 0, 1 and 2 interrupt status bits, and
use them instead of magic numbers when we're setting or checking for
these interrupts.
Also, add a #define for the class 2 mailbox threshold interrupt mask.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When doing a poll on the mbox stat file of a swapped-out context, we
clear the class 0 interrupt status, rather than the class 2 interrupt
status.
This change corrects the poll operation to clear the correct interrupt.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This change encapsulates the spu_privcntl_RW register so that it can
be written through backing ops. This is necessary so that spu contexts
can be initialized and queued to the scheduler in spufs_run_spu.
Signed-off-by: Luke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add platform specific SPU run control routines to the spufs. The current
spufs implementation uses the SPU master run control bit (MFC_SR1[S]) to
control SPE execution, but the PS3 hypervisor does not support the use of
this feature.
This change adds the run control wrapper routies spu_enable_spu() and
spu_disable_spu(). The bare metal routines use the master run control
bit, and the PS3 specific routines use the priv2 run control register.
An outstanding enhancement for the PS3 would be to add a guard to check
for incorrect access to the spu problem state when the spu context is
disabled. This check could be implemented with a flag added to the spu
context that would inhibit mapping problem state pages, and a routine
to unmap spu problem state pages. When the spu is enabled with
ps3_enable_spu() the flag would be set allowing pages to be mapped,
and when the spu is disabled with ps3_disable_spu() the flag would be
cleared and mapped problem state pages would be unmapped.
Signed-off-by: Masato Noguchi <Masato.Noguchi@jp.sony.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When a process writes into the inbound spu mailbox (wbox) while the
context is saved, we accidentally break the contents of the mb_stat_R
register by clearing other entries of the mailbox status register. This
can cause the user side to hang.
This change fixes the problem by only altering the appropriate bits
of the mailbox status register during a backing-store write.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The function backing_ops->read_mfc_tagstatus() doesn't return a
correct value because the dma_tagstatus_R register isn't saved in
CSA. This fixes the problem.
Signed-off-by: Kazunori Asayama <asayama@sm.sony.co.jp>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Until now, we have always entered the spu page fault handler
with a mutex for the spu context held. This has multiple
bad side-effects:
- it becomes impossible to suspend the context during
page faults
- if an spu program attempts to access its own mmio
areas through DMA, we get an immediate livelock when
the nopage function tries to acquire the same mutex
This patch makes the page fault logic operate on a
struct spu_context instead of a struct spu, and moves it
from spu_base.c to a new file fault.c inside of spufs.
We now also need to copy the dar and dsisr contents
of the last fault into the saved context to have it
accessible in case we schedule out the context before
activating the page fault handler.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
This change adds a read accessor for the SPE problem-state run control
register.
This is required for for applying (userspace) changes made to the run
control register while the SPE is stopped - simply asserting the master
run control bit is not sufficient. My next patch for isolated-mode
setup requires this.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When the user changes the runcontrol register, an SPU might be
running without a process being attached to it and waiting for
events. In order to prevent this, make sure we always disable
the priv1 master control when we're not inside of spu_run.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The /lslr file gives read access to the SPU_LSLR register in hex; 0x3fff
for example The /dma_info file provides read access to the SPU Command
Queue in a binary format. The /proxydma_info files provides read access
access to the Proxy Command Queue in a binary format. The spu_info.h
file provides data structures for interpreting the binary format of
/dma_info and /proxydma_info.
Signed-off-by: Dwayne Grant McConnell <decimal@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul 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: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul 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: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul 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: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Masato Noguchi
Andre Detsch
Jeremy Kerr
Luke Browning
Arnd Bergmann
Kazunori Asayama
Randy Dunlap
Arnd Bergmann
Dwayne Grant McConnell
Jörn Engel
Arnd Bergmann