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 <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
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: Arnd Bergmann <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
powerpc currently declares some of its own system calls
in <asm/unistd.h>, but not all of them. That place also
contains remainders of the now almost unused kernel syscall
hack.
- Add a new <asm/syscalls.h> with clean declarations
- Include that file from every source that implements one
of these
- Get rid of old declarations in <asm/unistd.h>
This patch is required as a base for implementing system
calls from an SPU, but also makes sense as a general
cleanup.
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
Apparently we have found a bug in the CPU that causes
external interrupts to sometimes get disabled indefinitely.
This adds a workaround for the problem.
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
The default configuration in mainline got a little out of
sync with what we use internally.
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
A small bug crept in the iommu driver when we made it more
generic. This patch is needed for boards that have a dma
window that does not start at bus address zero.
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
All architecture independent system calls should be declared
in syscalls.h, add the one that is missing.
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Arnd Bergmann