Merge a few asm-ppc and asm-ppc64 header files.
Note: the merge of setup.h intentionally does not carry
forward the m68k cruft. That means this patch continues
to break the already broken amiga on the ppc32.
Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There were three changes necessary in order to allow
sparc64 to use setup-res.c:
1) Sparc64 roots the PCI I/O and MEM address space using
parent resources contained in the PCI controller structure.
I'm actually surprised no other platforms do this, especially
ones like Alpha and PPC{,64}. These resources get linked into the
iomem/ioport tree when PCI controllers are probed.
So the hierarchy looks like this:
iomem --|
PCI controller 1 MEM space --|
device 1
device 2
etc.
PCI controller 2 MEM space --|
...
ioport --|
PCI controller 1 IO space --|
...
PCI controller 2 IO space --|
...
You get the idea. The drivers/pci/setup-res.c code allocates
using plain iomem_space and ioport_space as the root, so that
wouldn't work with the above setup.
So I added a pcibios_select_root() that is used to handle this.
It uses the PCI controller struct's io_space and mem_space on
sparc64, and io{port,mem}_resource on every other platform to
keep current behavior.
2) quirk_io_region() is buggy. It takes in raw BUS view addresses
and tries to use them as a PCI resource.
pci_claim_resource() expects the resource to be fully formed when
it gets called. The sparc64 implementation would do the translation
but that's absolutely wrong, because if the same resource gets
released then re-claimed we'll adjust things twice.
So I fixed up quirk_io_region() to do the proper pcibios_bus_to_resource()
conversion before passing it on to pci_claim_resource().
3) I was mistakedly __init'ing the function methods the PCI controller
drivers provide on sparc64 to implement some parts of these
routines. This was, of course, easy to fix.
So we end up with the following, and that nasty SPARC64 makefile
ifdef in drivers/pci/Makefile is finally zapped.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a race condition where in system used to hang or sometime
crash within minutes when kprobes are inserted on ISR routine and a task
routine.
The fix has been stress tested on i386, ia64, pp64 and on x86_64. To
reproduce the problem insert kprobes on schedule() and do_IRQ() functions
and you should see hang or system crash.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the ppc64 architecture specific changes to prevent the
possible race conditions.
Signed-off-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes sense now that we have asm-powerpc.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These two files are basically identical, so make one just include the other
(protecting the 32-bit-only parts with __powerpc64__). Also remove some
completely unused defines.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This set of patches creates asm-generic/fcntl.h and consolidates as much as
possible from the asm-*/fcntl.h files into it.
This patch just gathers all the identical bits of the asm-*/fcntl.h files into
asm-generic/fcntl.h.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
IRQ_PER_CPU is not used by all architectures. This patch introduces the
macros ARCH_HAS_IRQ_PER_CPU and CHECK_IRQ_PER_CPU() to avoid the generation
of dead code in __do_IRQ().
ARCH_HAS_IRQ_PER_CPU is defined by architectures using IRQ_PER_CPU in their
include/asm_ARCH/irq.h file.
Through grepping the tree I found the following architectures currently use
IRQ_PER_CPU:
cris, ia64, ppc, ppc64 and parisc.
Signed-off-by: Karsten Wiese <annabellesgarden@yahoo.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The size of auxiliary vector is fixed at 42 in linux/sched.h. But it isn't
very obvious when looking at linux/elf.h. This patch adds AT_VECTOR_SIZE
so that we can change it if necessary when a new vector is added.
Because of include file ordering problems, doing this necessitated the
extraction of the AT_* symbols into a standalone header file.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When I first wrote the compat layer patches, I was somewhat cavalier about
the definition of compat_uid_t and compat_gid_t (or maybe I just
misunderstood :-)). This patch makes the compat types much more consistent
with the types we are being compatible with and hopefully will fix a few
bugs along the way.
compat type type in compat arch
__compat_[ug]id_t __kernel_[ug]id_t
__compat_[ug]id32_t __kernel_[ug]id32_t
compat_[ug]id_t [ug]id_t
The difference is that compat_uid_t is always 32 bits (for the archs we
care about) but __compat_uid_t may be 16 bits on some.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ATM pthread_cond_signal is unnecessarily slow, because it wakes one waiter
(which at least on UP usually means an immediate context switch to one of
the waiter threads). This waiter wakes up and after a few instructions it
attempts to acquire the cv internal lock, but that lock is still held by
the thread calling pthread_cond_signal. So it goes to sleep and eventually
the signalling thread is scheduled in, unlocks the internal lock and wakes
the waiter again.
Now, before 2003-09-21 NPTL was using FUTEX_REQUEUE in pthread_cond_signal
to avoid this performance issue, but it was removed when locks were
redesigned to the 3 state scheme (unlocked, locked uncontended, locked
contended).
Following scenario shows why simply using FUTEX_REQUEUE in
pthread_cond_signal together with using lll_mutex_unlock_force in place of
lll_mutex_unlock is not enough and probably why it has been disabled at
that time:
The number is value in cv->__data.__lock.
thr1 thr2 thr3
0 pthread_cond_wait
1 lll_mutex_lock (cv->__data.__lock)
0 lll_mutex_unlock (cv->__data.__lock)
0 lll_futex_wait (&cv->__data.__futex, futexval)
0 pthread_cond_signal
1 lll_mutex_lock (cv->__data.__lock)
1 pthread_cond_signal
2 lll_mutex_lock (cv->__data.__lock)
2 lll_futex_wait (&cv->__data.__lock, 2)
2 lll_futex_requeue (&cv->__data.__futex, 0, 1, &cv->__data.__lock)
# FUTEX_REQUEUE, not FUTEX_CMP_REQUEUE
2 lll_mutex_unlock_force (cv->__data.__lock)
0 cv->__data.__lock = 0
0 lll_futex_wake (&cv->__data.__lock, 1)
1 lll_mutex_lock (cv->__data.__lock)
0 lll_mutex_unlock (cv->__data.__lock)
# Here, lll_mutex_unlock doesn't know there are threads waiting
# on the internal cv's lock
Now, I believe it is possible to use FUTEX_REQUEUE in pthread_cond_signal,
but it will cost us not one, but 2 extra syscalls and, what's worse, one of
these extra syscalls will be done for every single waiting loop in
pthread_cond_*wait.
We would need to use lll_mutex_unlock_force in pthread_cond_signal after
requeue and lll_mutex_cond_lock in pthread_cond_*wait after lll_futex_wait.
Another alternative is to do the unlocking pthread_cond_signal needs to do
(the lock can't be unlocked before lll_futex_wake, as that is racy) in the
kernel.
I have implemented both variants, futex-requeue-glibc.patch is the first
one and futex-wake_op{,-glibc}.patch is the unlocking inside of the kernel.
The kernel interface allows userland to specify how exactly an unlocking
operation should look like (some atomic arithmetic operation with optional
constant argument and comparison of the previous futex value with another
constant).
It has been implemented just for ppc*, x86_64 and i?86, for other
architectures I'm including just a stub header which can be used as a
starting point by maintainers to write support for their arches and ATM
will just return -ENOSYS for FUTEX_WAKE_OP. The requeue patch has been
(lightly) tested just on x86_64, the wake_op patch on ppc64 kernel running
32-bit and 64-bit NPTL and x86_64 kernel running 32-bit and 64-bit NPTL.
With the following benchmark on UP x86-64 I get:
for i in nptl-orig nptl-requeue nptl-wake_op; do echo time elf/ld.so --library-path .:$i /tmp/bench; \
for j in 1 2; do echo ( time elf/ld.so --library-path .:$i /tmp/bench ) 2>&1; done; done
time elf/ld.so --library-path .:nptl-orig /tmp/bench
real 0m0.655s user 0m0.253s sys 0m0.403s
real 0m0.657s user 0m0.269s sys 0m0.388s
time elf/ld.so --library-path .:nptl-requeue /tmp/bench
real 0m0.496s user 0m0.225s sys 0m0.271s
real 0m0.531s user 0m0.242s sys 0m0.288s
time elf/ld.so --library-path .:nptl-wake_op /tmp/bench
real 0m0.380s user 0m0.176s sys 0m0.204s
real 0m0.382s user 0m0.175s sys 0m0.207s
The benchmark is at:
http://sourceware.org/ml/libc-alpha/2005-03/txt00001.txt
Older futex-requeue-glibc.patch version is at:
http://sourceware.org/ml/libc-alpha/2005-03/txt00002.txt
Older futex-wake_op-glibc.patch version is at:
http://sourceware.org/ml/libc-alpha/2005-03/txt00003.txt
Will post a new version (just x86-64 fixes so that the patch
applies against pthread_cond_signal.S) to libc-hacker ml soon.
Attached is the kernel FUTEX_WAKE_OP patch as well as a simple-minded
testcase that will not test the atomicity of the operation, but at least
check if the threads that should have been woken up are woken up and
whether the arithmetic operation in the kernel gave the expected results.
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Jamie Lokier <jamie@shareable.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently, we set the class bit in kernel SLB entries, and clear it on
user SLB entries. On POWER5, ERAT entries created in real mode have
the class bit clear. So to avoid flushing kernel ERAT entries on each
context switch, this patch inverts our usage of the class bit, setting
it on user SLB entries and clearing it on kernel SLB entries.
Booted on POWER5 and G5.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move oprofile_impl.h into include/asm-ppc64 in preparation for moving
oprofile_model into cpu feature struct.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Remove the CPU_FTR_PMC8 feature now we encode the number of PMCs
directly.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a field in the cputable struct to store the number of PMCs.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch merges several include files from
asm-ppc and asm-ppc64 into the new asm-powerpc.
Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Merged several nearly-identical header files from asm-ppc and asm-ppc64
into asm-powerpc.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
cmpxchg has the following code:
__typeof__(*(ptr)) _o_ = (o);
__typeof__(*(ptr)) _n_ = (n);
Unfortunately it makes gcc 4.0 store and load the variables to the stack.
Eg in atomic_dec_and_test we get:
stw r10,112(r1)
stw r9,116(r1)
lwz r9,112(r1)
lwz r0,116(r1)
x86 is just casting the values so do that instead. Also change __xchg*
and __cmpxchg* to take unsigned values, removing a few sign extensions.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Consolidate the early console and PPCDBG code in udbg.c
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Take udbg out of ppc_md. Allows us to not overwrite early udbg inits
when assigning ppc_md.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We need to indicate to the hypervisor that it needs to save our VMX
registers when switching partitions on a shared-processor system, just as
it needs to for FP and PMC registers.
This could be made to be on-demand when VMX is used, but we don't do that
for FP nor PMC right now either so let's not overcomplicate things.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: <engebret@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is used only in slab.c and each architecture gets to define whcih
underlying type is to be used.
Seems a bit silly - move it to slab.c and use the same type for all
architectures: unsigned int.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Someone mentioned that almost all the architectures used basically the same
implementation of get_order. This patch consolidates them into
asm-generic/page.h and includes that in the appropriate places. The
exceptions are ia64 and ppc which have their own (presumably optimised)
versions.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A new option for SPARSEMEM is ARCH_SPARSEMEM_EXTREME. Architecture
platforms with a very sparse physical address space would likely want to
select this option. For those architecture platforms that don't select the
option, the code generated is equivalent to SPARSEMEM currently in -mm.
I'll be posting a patch on ia64 ml which uses this new SPARSEMEM feature.
ARCH_SPARSEMEM_EXTREME makes mem_section a one dimensional array of
pointers to mem_sections. This two level layout scheme is able to achieve
smaller memory requirements for SPARSEMEM with the tradeoff of an
additional shift and load when fetching the memory section. The current
SPARSEMEM -mm implementation is a one dimensional array of mem_sections
which is the default SPARSEMEM configuration. The patch attempts isolates
the implementation details of the physical layout of the sparsemem section
array.
ARCH_SPARSEMEM_EXTREME depends on 64BIT and is by default boolean false.
I've boot tested under aim load ia64 configured for ARCH_SPARSEMEM_EXTREME.
I've also boot tested a 4 way Opteron machine with !ARCH_SPARSEMEM_EXTREME
and tested with aim.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While ppc64 has the CONFIG_HZ Kconfig option, it wasnt actually being
used. Connect it up and set all platforms to 250Hz.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Here's the 970MP's PVR (processor version register) entry for oprofile.
Signed-off-by: Jake Moilanen <moilanen@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
They differed in either simple comments or in the protecting ifdefs.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Move the identical files from include/asm-ppc{,64}/ to
include/asm-powerpc/. Remove hdreg.h completely as it is unused in
the tree.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The ppc and ppc64 trees are hopefully going to merge over time, so this
patch begins the process by creating a place for the merging of the
header files.
Create include/asm-powerpc (and move linkage.h into it from
asm-{ppc,ppc64} since we don't like empty directories). Modify the
ppc and ppc64 Makefiles to cope.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Create vio_bus_ops so that we just pass a structure to vio_bus_init
instead of three separate function pointers.
Rearrange vio.h to avoid forward references. vio.h only needs
struct device_node from prom.h so remove the include and just
declare it.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Take some assignments out of vio_register_device_common and
rename it to vio_register_device.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
With CONFIG_HUGETLB_PAGE=n:
In file included from kernel/sysctl.c:37:
include/linux/hugetlb.h:104:1: warning: "hugetlb_free_pgd_range" redefined
In file included from include/linux/mm.h:36,
from kernel/sysctl.c:23:
include/asm/pgtable.h:492:1: warning: this is the location of the previous definition
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Paulus, I think this is now a reasonable candidate for the post-2.6.13
queue.
Relax address restrictions for hugepages on ppc64
Presently, 64-bit applications on ppc64 may only use hugepages in the
address region from 1-1.5T. Furthermore, if hugepages are enabled in
the kernel config, they may only use hugepages and never normal pages
in this area. This patch relaxes this restriction, allowing any
address to be used with hugepages, but with a 1TB granularity. That
is if you map a hugepage anywhere in the region 1TB-2TB, that entire
area will be reserved exclusively for hugepages for the remainder of
the process's lifetime. This works analagously to hugepages in 32-bit
applications, where hugepages can be mapped anywhere, but with 256MB
(mmu segment) granularity.
This patch applies on top of the four level pagetable patch
(http://patchwork.ozlabs.org/linuxppc64/patch?id=1936).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch moves power4_enable_pmcs() to arch/ppc64/kernel/pmc.c.
I've tested it on P5 LPAR and P4. It does what it used to.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
If both CONFIG_XMON and CONFIG_XMON_DEFAULT is enabled in the .config,
there is no way to disable xmon again. setup_system calls first xmon_init,
later parse_early_param. So a new 'xmon=off' cmdline option will do the right
thing.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We can now remove CONFIG_MSCHUNKS as it doesn't do anything interesting
anymore.
The only macro in abs_addr.h which is called by non-iSeries code is
phys_to_abs(), so remove the other dummy implementations, and we add a
firmware feature check to phys_to_abs().
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
We no longer need the lmb code to know about abs and phys addresses, so
remove the physbase variable from the lmb_property struct.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
abs_to_phys() is a macro that turns out to do nothing, and also has the
unfortunate property that it's not the inverse of phys_to_abs() on iSeries.
The following is for my benefit as much as everyone else.
With CONFIG_MSCHUNKS enabled, the lmb code is changed such that it keeps
a physbase variable for each lmb region. This is used to take the possibly
discontiguous lmb regions and present them as a contiguous address space
beginning from zero.
In this context each lmb region's base address is its "absolute" base
address, and its physbase is it's "physical" address (from Linux's point of
view). The abs_to_phys() macro does the mapping from "absolute" to "physical".
Note: This is not related to the iSeries mapping of physical to absolute
(ie. Hypervisor) addresses which is maintained with the msChunks structure.
And the msChunks structure is not controlled via CONFIG_MSCHUNKS.
Once upon a time you could compile for non-iSeries with CONFIG_MSCHUNKS
enabled. But these days CONFIG_MSCHUNKS depends on CONFIG_PPC_ISERIES, so
for non-iSeries code abs_to_phys() is a no-op.
On iSeries we always have one lmb region which spans from 0 to
systemcfg->physicalMemorySize (arch/ppc64/kernel/iSeries_setup.c line 383).
This region has a base (ie. absolute) address of 0, and a physbase address
of 0 (as calculated in lmb_analyze() (arch/ppc64/kernel/lmb.c line 144)).
On iSeries, abs_to_phys(aa) is defined as lmb_abs_to_phys(aa), which finds
the lmb region containing aa (and there's only one, ie. 0), and then does:
return lmb.memory.region[0].physbase + (aa - lmb.memory.region[0].base)
physbase == base == 0, so you're left with "return aa".
So remove abs_to_phys(), and lmb_abs_to_phys() which is the implementation
of abs_to_phys() for iSeries.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
physRpn_to_absRpn is a no-op on non-iSeries platforms, remove the two
redundant calls.
There's only one caller on iSeries so fold the logic in there so we can get
rid of it completely.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The only caller of chunk_offset() and abs_chunk() is phys_to_abs(), so
fold the former two into the latter.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Rename the msChunks struct to get rid of the StUdlY caps and make it a bit
clearer what it's for.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Chunks are 256KB, so use constants for the size/shift/mask, rather than
getting them from the msChunks struct. The iSeries debugger (??) might still
need access to the values in the msChunks struct, so we keep them around
for now, but set them from the constant values.
Replace msChunks_entry typedef with regular u32.
Simplify msChunks_alloc() to manipulate klimit directly, rather than via
a parameter.
Move msChunks_alloc() and msChunks into iSeries_setup.c, as that's where
they're used.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The msChunks code was written to work on pSeries, but now it's only used on
iSeries. This means there's no need to do PTRRELOC anymore, so remove it all.
A few places were getting "extern reloc_offset()" from abs_addr.h, move it
into system.h instead.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make firmware_has_feature() evaluate at compile time for the non pSeries
case and tidy up code where possible.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Create the firmware_has_feature() inline and move the firmware feature
stuff into its own header file.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The firmware_features field of struct cpu_spec should really be a separate
variable as the firmware features do not depend on the chip and the
bitmask is constructed independently. By removing it, we save 112 bytes
from the cpu_specs array and we access the bitmask directly instead of via
the cur_cpu_spec pointer.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On ppc64 machines with segment tables, CPU0's segment table is at a
fixed address, currently 0x9000. This patch moves it to the free
space at 0x6000, just below the fwnmi data area. This saves 8k of
space in vmlinux and the runtime kernel image.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Comments in head.S suggest that the iSeries naca has a fixed address,
because tools expect to find it there. The only tool which appears to
access the naca is addRamDisk, but both the in-kernel version and the
version used in RHEL and SuSE in fact locate the NACA the same way as
the hypervisor does, by following the pointer in the hvReleaseData
structure.
Since the requirement for a fixed address seems to be obsolete, this
patch removes the naca from head.S and replaces it with a normal C
initializer.
For good measure, it removes an old version of addRamDisk.c which was
sitting, unused, in the ppc32 tree.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch just splits out the pSeries specific parts of vio.c.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch allows us to have a different bus if matching function for
each platform.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since the iSeries vio iommu tables cannot be used until after the vio bus has
been initialised, move the initialisation of the tables to there.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch splits the iSeries specific parts out of vio.c.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch updates the format of the flattened device-tree passed
between the boot trampoline and the kernel to support a more compact
representation, for use by embedded systems mostly.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Implement 4-level pagetables for ppc64
This patch implements full four-level page tables for ppc64, thereby
extending the usable user address range to 44 bits (16T).
The patch uses a full page for the tables at the bottom and top level,
and a quarter page for the intermediate levels. It uses full 64-bit
pointers at every level, thus also increasing the addressable range of
physical memory. This patch also tweaks the VSID allocation to allow
matching range for user addresses (this halves the number of available
contexts) and adds some #if and BUILD_BUG sanity checks.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
I recently had a BUG_ON() go off spuriously on a gcc 4.0 compiled kernel.
It turns out gcc-4.0 was removing a sign extension while earlier gcc
versions would not. Thinking this to be a compiler bug, I submitted a
report:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23422
It turns out we need to cast the input in order to tell gcc to sign extend
it.
Thanks to Andrew Pinski for his help on this bug.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Paulus suggested that we put xLparMap in its own .c file so that we can
generate a .s file to be included into head.S. This doesn't get around
the problem of having it at a fixed address, but it makes it more
palatable.
It would be good if this could be included in 2.6.13 as it solves our
build problems with various versions of binutils and gcc. In
particular, it allows us to build an iSeries kernel on Debian unstable
using their biarch compiler.
This has been built and booted on iSeries and built for pSeries and g5.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In yenta_socket, we default to using the resource setting of the CardBus
bridge. However, this is a PCI-bus-centric view of resources and thus needs
to be converted to generic resources first. Therefore, add a call to
pcibios_bus_to_resource() call in between. This function is a mere wrapper on
x86 and friends, however on some others it already exists, is added in this
patch (alpha, arm, ppc, ppc64) or still needs to be provided (parisc -- where
is its pcibios_resource_to_bus() ?).
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The kexec boot is not successful on some power machines since all CPUs are
getting removed from global interrupt queue (GIQ) before kexec boot. Some
systems always expect at least one CPU in GIQ. Hence, this patch will make
sure that only secondary CPUs are removed from GIQ.
Signed-off-by: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Dont include asm-generic/topology.h unconditionally, we end up overriding
all the ppc64 specific functions when NUMA is on.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
inotify system call support for PPC64
[ I don't think we need sys32 compatibility versions--and if we do, I
failed in life. ]
Signed-off-by: Robert Love <rml@novell.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Presently the LparMap, one of the structures the kernel shares with the
legacy iSeries hypervisor has a fixed offset address in head.S. This patch
changes this so the LparMap is a normally initialized structure, without
fixed address. This allows us to use macros to compute some of the values
in the structure, which wasn't previously possible because the assembler
always uses signed-% which gets the wrong answers for the computations in
question.
Unfortunately, a gcc bug means that doing this requires another structure
(hvReleaseData) to be initialized in asm instead of C, but on the whole the
result is cleaner than before.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
PPC64 machines before Power4 need a segment table page allocated for each
CPU. Currently these are allocated statically in a big array in head.S for
all CPUs. The segment tables need to be in the first segment (so
do_stab_bolted doesn't take a recursive fault on the stab itself), but
other than that there are no constraints which require the stabs for the
secondary CPUs to be statically allocated.
This patch allocates segment tables dynamically during boot, using
lmb_alloc() to ensure they are within the first 256M segment. This reduces
the kernel image size by 192k...
Tested on RS64 iSeries, POWER3 pSeries, and POWER5.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When the kernel is working well and we want to restart cleanly
kernel_restart is the function to use. But in many instances
the kernel wants to reboot when thing are expected to be working
very badly such as from panic or a software watchdog handler.
This patch adds the function emergency_restart() so that
callers can be clear what semantics they expect when calling
restart. emergency_restart() is expected to be callable
from interrupt context and possibly reliable in even more
trying circumstances.
This is an initial generic implementation for all architectures.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes the use of bitfield types from the ppc64 hash table
manipulation code.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
http://bugme.osdl.org/show_bug.cgi?id=4016
Written-by: David Shaohua Li <shaohua.li@intel.com>
Acked-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch adds an idle member to the ppc_md structure and calls it from
cpu_idle(). If a platform leaves ppc_md.idle as null it will get the default
idle loop default_idle().
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When registering the hvc console port, register a list of ops (read and write)
to go with it, instead of calling fixed function names.
This allows different ports to encode the data differently.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove all the vio device driver code from hvc_console.c
This will allow us to separate hvsi, hvc, and allow hvc_console to be used
without the ppc64 vio layer.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Separate the console setup routines of the hvc_console and the vio layer.
Remove the call to find_init_vty from hvc_console.c.
Fail the setup routine if the console doesn't exist, but register the console
again when the specified channel is instantiated. This scheme maintains the
print buffer semantics while eliminating callout and call back for the console
code.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We already have a prototype for sys_remap_file_pages (239) so there is no need
to reserve it twice.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Enable the runlatch at the start of each exception. Unfortunately we are out
of space in the 0x300 handler, so I added it a bit later.
The SPR write is fairly expensive, perhaps we should cache the runlatch state
in the paca and avoid the write when possible.
We don't need to turn the runlatch off, we do that in the idle loop. Better
to take the hit in the idle loop than for each exception exit.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Not all ppc64 CPUs have the CTRL SPR, so we need a cputable feature for it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The hvlpevent_queue (formally ItLpQueue) has a member called xInUseWord
which is used for serialising access to the queue. Because it's a word
(ie. 32 bit) there's a custom 32-bit version of test_and_set_bit() or
thereabouts in ItLpQueue.c.
The xInUseWord is not shared with they hypervisor, so we can replace it
with a spinlock and remove the custom code.
There is also another locking mechanism (ItLpQueueInProcess). This is
redundant because it's only manipulated while the lock's held. Remove it.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently there's a per-cpu count of lpevents processed, a per-queue (ie.
global) total count, and a count by event type.
Replace all that with a count by event for each cpu. We only need to add
it up int the proc code.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently we count the number of lpevents processed in 3 seperate places.
One of these counters is never read, so just remove it. This means
hvlpevent_queue_process() no longer needs to return the number of events
processed.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now that we've renamed the xItLpQueue structure, rename the functions that
operate on it also.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The xItLpQueue is a queue of HvLpEvents that we're given by the Hypervisor.
Rename xItLpQueue to hvlpevent_queue and make the type struct hvlpevent_queue.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
External parties don't need to use ItLpQueue_getNextLpEvent() or
ItLpQueue_clearValid(), they're internal to ItLpQueue.c
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The xItLpQueue is initalised manually in iSeries_setup_arch(). Move
this code into ItLpQueue.c for a cleaner separation.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Because there's only one ItLpQueue and we know where it is, ie. xItLpQueue,
there's no point passing pointers to it it around all over the place.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The iSeries code keeps a pointer to the ItLpQueue in its paca struct. But
all these pointers end up pointing to the one place, ie. xItLpQueue.
So remove the pointer from the paca struct and just refer to xItLpQueue
directly where needed.
The only complication is that the spread_lpevents logic was implemented by
having a NULL lpqueue pointer in the paca on CPUs that weren't supposed to
process events. Instead we just compare the spread_lpevents value to the
processor id to get the same behaviour.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch cleans up asm-ppc64/byteorder.h to enable ___arch__swab16 and
___arch__swab32 which are marked TODO currently. It removes ___arch__swab64
because ppc64 does not have short instruction combinations for swab64, the
recent gcc generates enough smart code that is equivalent to hand assembled
code under my tests.
Signed-off-by: GOTO Masanori <gotom@debian.or.jp>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With CONFIG_PCI=n:
In file included from include/linux/pci.h:917,
from lib/iomap.c:6:
include/asm/pci.h:104: warning: `enum pci_dma_burst_strategy' declared inside parameter list
include/asm/pci.h:104: warning: its scope is only this definition or declaration, which is probably not what you want.
include/asm/pci.h: In function `pci_dma_burst_advice':
include/asm/pci.h:106: dereferencing pointer to incomplete type
include/asm/pci.h:106: `PCI_DMA_BURST_INFINITY' undeclared (first use in this function)
include/asm/pci.h:106: (Each undeclared identifier is reported only once
include/asm/pci.h:106: for each function it appears in.)
make[1]: *** [lib/iomap.o] Error 1
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After seeing, at best, "guesses" as to the following kind
of information in several drivers, I decided that we really
need a way for platforms to specifically give advice in this
area for what works best with their PCI controller implementation.
Basically, this new interface gives DMA bursting advice on
PCI. There are three forms of the advice:
1) Burst as much as possible, it is not necessary to end bursts
on some particular boundary for best performance.
2) Burst on some byte count multiple. A DMA burst to some multiple of
number of bytes may be done, but it is important to end the burst
on an exact multiple for best performance.
The best example of this I am aware of are the PPC64 PCI
controllers, where if you end a burst mid-cacheline then
chip has to refetch the data and the IOMMU translations
which hurts performance a lot.
3) Burst on a single byte count multiple. Bursts shall end
exactly on the next multiple boundary for best performance.
Sparc64 and Alpha's PCI controllers operate this way. They
disconnect any device which tries to burst across a cacheline
boundary.
Actually, newer sparc64 PCI controllers do not have this behavior.
That is why the "pdev" is passed into the interface, so I can
add code later to check which PCI controller the system is using
and give advice accordingly.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is an updated version of Ben's fix-pci-mmap-on-ppc-and-ppc64.patch
which is in 2.6.12-rc4-mm1.
It fixes the patch to work on PPC iSeries, removes some debug printks
at Ben's request, and incorporates your
fix-pci-mmap-on-ppc-and-ppc64-fix.patch also.
Originally from Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch was discussed at length on linux-pci and so far, the last
iteration of it didn't raise any comment. It's effect is a nop on
architecture that don't define the new pci_resource_to_user() callback
anyway. It allows architecture like ppc who put weird things inside of
PCI resource structures to convert to some different value for user
visible ones. It also fixes mmap'ing of IO space on those archs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The following is a patch provided by Ananth Mavinakayanahalli that implements
the new PPC64 specific parts of the new function return probe design.
NOTE: Since getting Ananth's patch, I changed trampoline_probe_handler()
to consume each of the outstanding return probem instances (feedback
on my original RFC after Ananth cut a patch), and also added the
arch_init() function (adding arch specific initialization.) I have
cross compiled but have not testing this on a PPC64 machine.
Changes include:
* Addition of kretprobe_trampoline to act as a dummy function for instrumented
functions to return to, and for the return probe infrastructure to place
a kprobe on on, gaining control so that the return probe handler
can be called, and so that the instruction pointer can be moved back
to the original return address.
* Addition of arch_init(), allowing a kprobe to be registered on
kretprobe_trampoline
* Addition of trampoline_probe_handler() which is used as the pre_handler
for the kprobe inserted on kretprobe_implementation. This is the function
that handles the details for calling the return probe handler function
and returning control back at the original return address
* Addition of arch_prepare_kretprobe() which is setup as the pre_handler
for a kprobe registered at the beginning of the target function by
kernel/kprobes.c so that a return probe instance can be setup when
a caller enters the target function. (A return probe instance contains
all the needed information for trampoline_probe_handler to do it's job.)
* Hooks added to the exit path of a task so that we can cleanup any left-over
return probe instances (i.e. if a task dies while inside a targeted function
then the return probe instance was reserved at the beginning of the function
but the function never returns so we need to mark the instance as unused.)
Signed-off-by: Rusty Lynch <rusty.lynch@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now that PPC64 has no-execute support, here is a second try to fix the
single step out of line during kprobe execution. Kprobes on x86_64 already
solved this problem by allocating an executable page and using it as the
scratch area for stepping out of line. Reuse that.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements the kexec support for ppc64 platforms.
A couple of notes:
1) We copy the pages in virtual mode, using the full base kernel
and a statically allocated stack. At kexec_prepare time we
scan the pages and if any overlap our (0, _end[]) range we
return -ETXTBSY.
On PowerPC 64 systems running in LPAR (logical partitioning)
mode, only a small region of memory, referred to as the RMO,
can be accessed in real mode. Since Linux runs with only one
zone of memory in the memory allocator, and it can be orders of
magnitude more memory than the RMO, looping until we allocate
pages in the source region is not feasible. Copying in virtual
means we don't have to write a hash table generation and call
hypervisor to insert translations, instead we rely on the pinned
kernel linear mapping. The kernel already has move to linked
location built in, so there is no requirement to load it at 0.
If we want to load something other than a kernel, then a stub
can be written to copy a linear chunk in real mode.
2) The start entry point gets passed parameters from the kernel.
Slaves are started at a fixed address after copying code from
the entry point.
All CPUs get passed their firmware assigned physical id in r3
(most calling conventions use this register for the first
argument).
This is used to distinguish each CPU from all other CPUs.
Since firmware is not around, there is no other way to obtain
this information other than to pass it somewhere.
A single CPU, referred to here as the master and the one executing
the kexec call, branches to start with the address of start in r4.
While this can be calculated, we have to load it through a gpr to
branch to this point so defining the register this is contained
in is free. A stack of unspecified size is available at r1
(also common calling convention).
All remaining running CPUs are sent to start at absolute address
0x60 after copying the first 0x100 bytes from start to address 0.
This convention was chosen because it matches what the kernel
has been doing itself. (only gpr3 is defined).
Note: This is not quite the convention of the kexec bootblock v2
in the kernel. A stub has been written to convert between them,
and we may adjust the kernel in the future to allow this directly
without any stub.
3) Destination pages can be placed anywhere, even where they
would not be accessible in real mode. This will allow us to
place ram disks above the RMO if we choose.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: R Sharada <sharada@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
