A few cleanups in hvc_rtas.c:
1. Remove unused RTASCONS_PUT_ATTEMPTS
2. Remove unused rtascons_put_delay.
3. Use i as a loop counter like everyone else on earth.
4. Remove pointless variables, eg. x = foo; if (x) return something_else;
5. Whitespace cleanups and formatting.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently the hvc_rtas driver is painfully slow to use. Our "benchmark" is
ls -R /etc, which spits out about 27866 characters. The theoretical maximum
speed would be about 2.2 seconds, the current code takes ~50 seconds.
The core of the problem is that sometimes when the tty layer asks us to push
characters the firmware isn't able to handle some or all of them, and so
returns an error. The current code sees this and just returns to the tty code
with the buffer half sent.
The khvcd thread will eventually wake up and try to push more characters, which
will usually work because by then the firmware's had time to make room. But
the khvcd thread only wakes up every 10 milliseconds, which isn't fast enough.
So change the khvcd thread logic so that if there's an incomplete write we
yield() and then immediately try writing again. Doing so makes POLL_QUICK and
POLL_WRITE synonymous, so remove POLL_QUICK.
With this patch our "benchmark" takes ~2.8 seconds.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This gives the ability to control whether alignment exceptions get
fixed up or reported to the process as a SIGBUS, using the existing
PR_SET_UNALIGN and PR_GET_UNALIGN prctls. We do not implement the
option of logging a message on alignment exceptions.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds the PowerPC part of the code to allow processes to change
their endian mode via prctl.
This also extends the alignment exception handler to be able to fix up
alignment exceptions that occur in little-endian mode, both for
"PowerPC" little-endian and true little-endian.
We always enter signal handlers in big-endian mode -- the support for
little-endian mode does not amount to the creation of a little-endian
user/kernel ABI. If the signal handler returns, the endian mode is
restored to what it was when the signal was delivered.
We have two new kernel CPU feature bits, one for PPC little-endian and
one for true little-endian. Most of the classic 32-bit processors
support PPC little-endian, and this is reflected in the CPU feature
table. There are two corresponding feature bits reported to userland
in the AT_HWCAP aux vector entry.
This is based on an earlier patch by Anton Blanchard.
Signed-off-by: Paul Mackerras <paulus@samba.org>
This new prctl is intended for changing the execution mode of the
processor, on processors that support both a little-endian mode and a
big-endian mode. It is intended for use by programs such as
instruction set emulators (for example an x86 emulator on PowerPC),
which may find it convenient to use the processor in an alternate
endianness mode when executing translated instructions.
Note that this does not imply the existence of a fully-fledged ABI for
both endiannesses, or of compatibility code for converting system
calls done in the non-native endianness mode. The program is expected
to arrange for all of its system call arguments to be presented in the
native endianness.
Switching between big and little-endian mode will require some care in
constructing the instruction sequence for the switch. Generally the
instructions up to the instruction that invokes the prctl system call
will have to be in the old endianness, and subsequent instructions
will have to be in the new endianness.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When debugging early kernel crashes that happen after console_init() and
before a proper console driver takes over, we often have to go hack into
udbg.c to prevent it from unregistering so we can "see" what is
happening. This patch adds a kernel command line option "udbg-immortal"
instead to avoid having to modify the kernel.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
POWER6 moves some of the MMCRA bits and also requires some bits to be
cleared each PMU interrupt.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make sure dma_alloc_coherent allocates memory from the local node. This
is important on Cell where we avoid going through the slow cpu
interconnect.
Note: I could only test this patch on Cell, it should be verified on
some pseries machine by those that have the hardware.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On 64bit powerpc we can find out what node a pci bus hangs off, so
implement the topology.h macros that export this information.
For 32bit this seems a little more difficult, but I don't know of 32bit
powerpc NUMA machines either, so let's leave it out for now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch attempts to handle RTAS "busy" return codes in a more simple
and consistent manner. Typical callers of RTAS shouldn't have to
manage wait times and delay calls.
This patch also changes the kernel to use msleep() rather than udelay()
when a runtime delay is necessary. This will avoid CPU soft lockups
for extended delay conditions.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
From: Andrew Morton <akpm@osdl.org>
arch/powerpc/Kconfig:339:warning: leading whitespace ignored
arch/powerpc/Kconfig:347:warning: leading whitespace ignored
arch/powerpc/Kconfig:357:warning: leading whitespace ignored
arch/powerpc/Kconfig:373:warning: leading whitespace ignored
arch/powerpc/Kconfig:382:warning: leading whitespace ignored
arch/powerpc/Kconfig:394:warning: leading whitespace ignored
arch/powerpc/Kconfig:842:warning: leading whitespace ignored
arch/powerpc/Kconfig:847:warning: leading whitespace ignored
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 970MP cputable entry needs a num_pmcs entry for oprofile to work.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
My js20 appears to lack the ibm,#dma- properties, and boot fails with a
"Kernel panic - not syncing: iommu_init_table: Can't allocate 0 bytes"
message.
This adds a fallback to the "#address-cells" property in case the
"#ibm,dma-address-cells" property is missing. Tested on js20 and
power5 lpar.
Unless there is a more elegant solution... :-)
Signed-off-by: Will Schmidt <willschm@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Our MMU hash management code would not set the "C" bit (changed bit) in
the hardware PTE when updating a RO PTE into a RW PTE. That would cause
the hardware to possibly to a write back to the hash table to set it on
the first store access, which in addition to being a performance issue,
might also hit a bug when running with native hash management (non-HV)
as our code is specifically optimized for the case where no write back
happens.
Thus there is a very small therocial window were a hash PTE can become
corrupted if that HPTE has just been upgraded to read write, a store
access happens on it, and that races with another processor evicting
that same slot. Since eviction (caused by an almost full hash) is
extremely rare, the bug is very unlikely to happen fortunately.
This fixes by allowing the updating of the protection bits in the native
hash handling to also set (but not clear) the "C" bit, and, in order to
also improve performances in the general case, by always setting that
bit on newly inserted hash PTE so that writeback really never happens.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch cleans up some locking & error handling in the ppc vdso and
moves the vdso base pointer from the thread struct to the mm context
where it more logically belongs. It brings the powerpc implementation
closer to Ingo's new x86 one and also adds an arch_vma_name() function
allowing to print [vsdo] in /proc/<pid>/maps if Ingo's x86 vdso patch is
also applied.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
I have tested PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS on umview.
I do not understand why historically these tags has been defined as
PPC_PTRACE_GETREGS and PPC_PTRACE_SETREGS instead of simply
PTRACE_[GS]ETREGS. The other "originality" is that the address must be
put into the "addr" field instead of the "data" field as stated in the
manual.
Signed-off-by: renzo davoli <renzo@cs.unibo.it>
Signed-off-by: Paul Mackerras <paulus@samba.org>
getting decremented by 1. Since nused never reaches 0, the "if
(!free->hdr.nused)" check in xfs_dir2_leafn_remove() fails every time and
xfs_dir2_shrink_inode() doesn't get called when it should. This causes
extra blocks to be left on an empty directory and the directory in unable
to be converted back to inline extent mode.
SGI-PV: 951958
SGI-Modid: xfs-linux-melb:xfs-kern:211382a
Signed-off-by: Mandy Kirkconnell <alkirkco@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
truncate down followed by delayed allocation (buffered writes) - worst
case scenario for the notorious NULL files problem. This reduces the
window where we are exposed to that problem significantly.
SGI-PV: 917976
SGI-Modid: xfs-linux-melb:xfs-kern:26100a
Signed-off-by: Nathan Scott <nathans@sgi.com>
init_rwsem() has no return value. This is not a problem if init_rwsem()
is a function, but it's a problem if it's a do { ... } while (0) macro.
(which lockdep introduces)
SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:26082a
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Nathan Scott <nathans@sgi.com>
logged version of di_next_unlinked which is actually always stored in the
correct ondisk format. This was pointed out to us by Shailendra Tripathi.
And is evident in the xfs qa test of 121.
SGI-PV: 953263
SGI-Modid: xfs-linux-melb:xfs-kern:26044a
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
transaction completion from marking the inode dirty while it is being
cleaned up on it's way out of the system.
SGI-PV: 952967
SGI-Modid: xfs-linux-melb:xfs-kern:26040a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
64bit kernels allow recovery to handle both versions and do the necessary
decoding
SGI-PV: 952214
SGI-Modid: xfs-linux-melb:xfs-kern:26011a
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
transaction within each such operation may involve multiple locking of AGF
buffer. While the freeing extent function has sorted the extents based on
AGF number before entering into transaction, however, when the file system
space is very limited, the allocation of space would try every AGF to get
space allocated, this could potentially cause out-of-order locking, thus
deadlock could happen. This fix mitigates the scarce space for allocation
by setting aside a few blocks without reservation, and avoid deadlock by
maintaining ascending order of AGF locking.
SGI-PV: 947395
SGI-Modid: xfs-linux-melb:xfs-kern:210801a
Signed-off-by: Yingping Lu <yingping@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
ATTR_NOLOCK flag, but this was split off some time ago, as ATTR_DMI needed
to be used separately. Two asserts were added to guard correctness of the
code during the transition. These are no longer required.
SGI-PV: 952145
SGI-Modid: xfs-linux-melb:xfs-kern:209633a
Signed-off-by: Olaf Weber <olaf@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
the range spanned by modifications to the in-core extent map. Add
XFS_BUNMAPI() and XFS_SWAP_EXTENTS() macros that call xfs_bunmapi() and
xfs_swap_extents() via the ioops vector. Change all calls that may modify
the in-core extent map for the data fork to go through the ioops vector.
This allows a cache of extent map data to be kept in sync.
SGI-PV: 947615
SGI-Modid: xfs-linux-melb:xfs-kern:209226a
Signed-off-by: Olaf Weber <olaf@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
The IBM Cell blade firmware might confuse the kernel to think it's a
pSeries machine. This fixes it for now. With a bit of luck, the firmware
will be updated to avoid that in the future but currently that patch is
needed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
