Commit Graph

87 Commits

Author SHA1 Message Date
Alan Stern
e041c68341 [PATCH] Notifier chain update: API changes
The kernel's implementation of notifier chains is unsafe.  There is no
protection against entries being added to or removed from a chain while the
chain is in use.  The issues were discussed in this thread:

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

We noticed that notifier chains in the kernel fall into two basic usage
classes:

	"Blocking" chains are always called from a process context
	and the callout routines are allowed to sleep;

	"Atomic" chains can be called from an atomic context and
	the callout routines are not allowed to sleep.

We decided to codify this distinction and make it part of the API.  Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name).  New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain.  The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.

With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed.  For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections.  (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)

There are some limitations, which should not be too hard to live with.  For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem.  Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain.  (This did happen in a couple of places and the code
had to be changed to avoid it.)

Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.

Here is the list of chains that we adjusted and their classifications.  None
of them use the raw API, so for the moment it is only a placeholder.

  ATOMIC CHAINS
  -------------
arch/i386/kernel/traps.c:		i386die_chain
arch/ia64/kernel/traps.c:		ia64die_chain
arch/powerpc/kernel/traps.c:		powerpc_die_chain
arch/sparc64/kernel/traps.c:		sparc64die_chain
arch/x86_64/kernel/traps.c:		die_chain
drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
kernel/panic.c:				panic_notifier_list
kernel/profile.c:			task_free_notifier
net/bluetooth/hci_core.c:		hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
net/ipv6/addrconf.c:			inet6addr_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
net/netlink/af_netlink.c:		netlink_chain

  BLOCKING CHAINS
  ---------------
arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
arch/s390/kernel/process.c:		idle_chain
arch/x86_64/kernel/process.c		idle_notifier
drivers/base/memory.c:			memory_chain
drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
drivers/macintosh/adb.c:		adb_client_list
drivers/macintosh/via-pmu.c		sleep_notifier_list
drivers/macintosh/via-pmu68k.c		sleep_notifier_list
drivers/macintosh/windfarm_core.c	wf_client_list
drivers/usb/core/notify.c		usb_notifier_list
drivers/video/fbmem.c			fb_notifier_list
kernel/cpu.c				cpu_chain
kernel/module.c				module_notify_list
kernel/profile.c			munmap_notifier
kernel/profile.c			task_exit_notifier
kernel/sys.c				reboot_notifier_list
net/core/dev.c				netdev_chain
net/decnet/dn_dev.c:			dnaddr_chain
net/ipv4/devinet.c:			inetaddr_chain

It's possible that some of these classifications are wrong.  If they are,
please let us know or submit a patch to fix them.  Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)

The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.

[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:44:50 -08:00
Stephen Rothwell
3158e9411a [PATCH] consolidate sys32/compat_adjtimex
Create compat_sys_adjtimex and use it an all appropriate places.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:56:57 -08:00
Stephen Rothwell
88959ea968 [PATCH] create struct compat_timex and use it everywhere
We had a copy of the compatibility version of struct timex in each 64 bit
architecture.  This patch just creates a global one and replaces all the
usages of the old ones.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26 08:56:57 -08:00
Adrian Bunk
cdb0452789 [PATCH] kill include/linux/platform.h, default_idle() cleanup
include/linux/platform.h contained nothing that was actually used except
the default_idle() prototype, and is therefore removed by this patch.

This patch does the following with the platform specific default_idle()
functions on different architectures:
- remove the unused function:
  - parisc
  - sparc64
- make the needlessly global function static:
  - arm
  - h8300
  - m68k
  - m68knommu
  - s390
  - v850
  - x86_64
- add a prototype in asm/system.h:
  - cris
  - i386
  - ia64

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Patrick Mochel <mochel@digitalimplant.org>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:21 -08:00
Andrew Morton
394e3902c5 [PATCH] more for_each_cpu() conversions
When we stop allocating percpu memory for not-possible CPUs we must not touch
the percpu data for not-possible CPUs at all.  The correct way of doing this
is to test cpu_possible() or to use for_each_cpu().

This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
few instances of this bug, if any.  But the patch converts lots of open-coded
test to use the preferred helper macros.

Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Kyle McMartin <kyle@parisc-linux.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Christian Zankel <chris@zankel.net>
Cc: Philippe Elie <phil.el@wanadoo.fr>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23 07:38:17 -08:00
Kyle McMartin
108dff7d2b [PATCH] sys_newfstatat -> sys_fstatat64
parisc defines ARCH_WANT_STAT64, so we want to use fstatat64. It does not
appear that it needs to be ENTRY_COMP, because struct stat64 is the same
on both 32-bit and 64-bit (unlike on other platforms which did define a
compat_sys_fstatat64.)

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-13 19:58:47 -08:00
Kyle McMartin
28b2425ac7 [PARISC] Stub out pselect6/ppoll until TIF_RESTORE_SIGMASK is done
Swap out pselect6/ppoll for ni_syscall for now. We also have to switch
the macro to ENTRY_SAME since compat_sys_ni_syscall does not exist.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-02-08 23:27:58 -05:00
Kyle McMartin
68ee3eb829 [PARISC] New syscalls (inotify, *at, pselect6/ppoll, migrate_pages)
Wire up some new syscalls that have been merged upstream,
  o inotify
  o openat et al
  o pselect6/ppoll
  o migrate_pages

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-30 00:53:14 -05:00
Kyle McMartin
f671c45df2 [PARISC] Arch-specific compat signals
Add enough arch-specific compat signals code to enable parisc64
to compile and boot out of the mainline tree. There are likely still
many dragons here, but this is a start to squashing the last
big difference between the mainline tree and the parisc-linux tree.
The remaining bugs can be squashed as they come up.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:57:42 -05:00
Helge Deller
1bcdd85482 [PARISC] Add CONFIG_DEBUG_RODATA to protect read-only data
Add the parisc version of the "mark rodata section read only" patches.
Based on code from and Signed-off-by Arjan van de Ven
<arjan@infradead.org>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@muc.de>,
Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:54 -05:00
Matthew Wilcox
a2bb214dcd [PARISC] Remove {,un}lock_kernel from perf ioctl
Remove the lock_kernel/unlock_kernel pair in the ioctl method. It
plainly wasn't protecting anything.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:52 -05:00
Kyle McMartin
85509c0007 [PARISC] Add chassis_power_off routine
Define a chassis_power_off routine that machines which have a way
to turn off the power supply can hook into. Formerly they were
using pm_power_off, which is now being used by generic code. Make
lasi.c use chassis_power_off instead of pm_power_off.

Note, all machines need to call machine_power_off so that the
switch can power off the machine, though halt -p may not necessarily
be able to work properly on the machine.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:50 -05:00
Kyle McMartin
526110f8c8 [PARISC] Remove obsolete _hlt cruft
Remove a bunch of obsolete code from process.c, these routines were
likely imported from the i386 version of process.c when the port
started. The routines are only used in floppy.c, which I seriously
doubt will ever work on parisc, due to architectural assumptions.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:48 -05:00
Kyle McMartin
9073315bbc [PARISC] Move pm_power_off export to process.c
Move the EXPORT_SYMBOL() of pm_power_off from parisc_ksyms.c to the
location of its definition in process.c

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:46 -05:00
Helge Deller
96629c0b11 [PARISC] Clean up compiler warning in pci.c
Avoid compiler warning for unused variables on 32bit kernels by
conditionalizing the local variables on CONFIG_64BIT. PCI_HOST_ADDR()
only uses the hba argument on 64bit compiles.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:43 -05:00
Kyle McMartin
10992092a8 [PARISC] Use F_EXTEND() for COMMAND_GLOBAL
Instead of wrapping the define of COMMAND_GLOBAL in #ifdef __LP64__
use the F_EXTEND() macro defined in asm/io.h, which is the preferred
way of extending mmio space addresses for either 32 or 64 bit machines.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:41 -05:00
Grant Grundler
2c9aadabf4 [PARISC] Remove unnecessary extern declarations from asm/pci.h
Remove two unnecessary extern declarations from asm/pci.h.
They collide with what gcc4.0 assumed was static (and should be static).
Found by Joel Soete.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:34 -05:00
Helge Deller
cb6fc18e9c [PARISC] Use kzalloc and other janitor-style cleanups
Helge,
  o Convert a bunch of kmalloc/memset uses to kzalloc.
  o pci.c: Add some __read_mostly annotations.
  o pci.c: Move constant pci_post_reset_delay to asm/pci.h
  o grfioctl.h: Add A4450A to comment of CRT_ID_VISUALIZE_EG.
  o Add some consts to perf.c/perf_images.h

Matthew,
  o sticore.c: Add some consts to suppress compile warnings.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-22 20:26:31 -05:00
Russell King
ad3ed31c68 [PATCH] Add parisc_bus_type probe and remove methods
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-13 11:26:06 -08:00
Al Viro
40f1f0deaf [PATCH] parisc: task_stack_page(), task_thread_info()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:08:55 -08:00
Randy Dunlap
a941564458 [PATCH] capable/capability.h (arch/)
arch: Use <linux/capability.h> where capable() is used.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:14 -08:00
Matthew Wilcox
58b6c58cae [PARISC] Use STABS_DEBUG macro from vmlinux.lds.h
Cleanup vmlinux.lds.S by using STABS_DEBUG macro from vmlinux.lds.h
instead of repeating the sections.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-10 21:53:19 -05:00
Matthew Wilcox
f45adcf977 [PARISC] Fix Dino reporting on J2240
Fix Dino reporting on J2240. This particular machine thought it
had a Cujo. Also add J2240 Dino chip to the hp_hardware_list.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-10 21:53:14 -05:00
Matthew Wilcox
a01c8cb126 [PARISC] Fix GSC graphics cards with 64MB regions
Make knapps work with its 64MB gfx card.  I probably just broke another
machine in the process, but assuming 64MB when 64MB aligned is probably
safer than assuming 32MB all the time.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-10 21:51:33 -05:00
Matthew Wilcox
1b2425e3c7 [PARISC] Make local cache flushes take a void *
Make flush_data_cache_local, flush_instruction_cache_local and
flush_tlb_all_local take a void * so they don't have to be cast
when using on_each_cpu().  This becomes a problem when on_each_cpu
is a macro (as it is in current -mm).

Also move the prototype of flush_tlb_all_local into tlbflush.h and
remove its declaration from .c files.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-10 21:49:21 -05:00
Helge Deller
8039de10aa [PARISC] Add __read_mostly section for parisc
Flag a whole bunch of things as __read_mostly on parisc. Also flag a few
branches as unlikely() and cleanup a bit of code.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2006-01-10 20:35:03 -05:00
Christoph Hellwig
e6a6d2efcb [PATCH] sanitize building of fs/compat_ioctl.c
Now that all these entries in the arch ioctl32.c files are gone [1], we can
build fs/compat_ioctl.c as a normal object and kill tons of cruft.  We need a
special do_ioctl32_pointer handler for s390 so the compat_ptr call is done.
This is not needed but harmless on all other architectures.  Also remove some
superflous includes in fs/compat_ioctl.c

Tested on ppc64.

[1] parisc still had it's PPP handler left, which is not fully correct
    for ppp and besides that ppp uses the generic SIOCPRIV ioctl so it'd
    kick in for all netdevice users.  We can introduce a proper handler
    in one of the next patch series by adding a compat_ioctl method to
    struct net_device but for now let's just kill it - parisc doesn't
    compile in mainline anyway and I don't want this to block this
    patchset.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:33 -08:00
Christoph Hellwig
ec3cad9690 [PATCH] move rtc compat ioctl handling to fs/compat_ioctl.c
This patch implements generic handling of RTC_IRQP_READ32, RTC_IRQP_SET32,
RTC_EPOCH_READ32 and RTC_EPOCH_SET32 in fs/compat_ioctl.c.  It's based on the
x86_64 code which needed a little massaging to be endian-clean.

parisc used COMPAT_IOCTL or generic w_long handlers for these whichce is wrong
and can't work because the ioctls encode sizeof(unsigned long) in their ioctl
number.  parisc also duplicated COMPAT_IOCTL entries for other rtc ioctls
which I remove in this patch, too.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:32 -08:00
Grant Grundler
9d7d57567c [PARISC] Remove unused variable in signal.c
Remove unused variable "struct siginfo si" in signal.c

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:43:52 -05:00
Christoph Hellwig
784412f74c [PARISC] remove drm compat ioctls handlers
Remove drm compat_ioctl handlers. The drm drivers have proper
compat_ioctl methods these days.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:41:26 -05:00
Christoph Hellwig
ad7dd338fb [PARISC] move PA perf driver over to ->compat_ioctl
Move PA perf driver over to ->compat_ioctl.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Randolph Chung <tausq@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:40:31 -05:00
Matthew Wilcox
83aceb5b6a [PARISC] Fix some compile problems in ptrace.c
Fix some compile problems:
- ret wasn't being initialised in all code paths
- I'm pretty sure 'goto out' should have been 'goto out_tsk'

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:37:24 -05:00
Matthew Wilcox
4269b0d371 [PARISC] Improve the error message when we get a clashing mod path
Improve the error message when we get a clashing mod path, and
actually display the IODC data and path for the conflicting device.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:33:56 -05:00
Matthew Wilcox
ba5c4f1bae [PARISC] Return PDC_OK when alloc_pa_dev fails to enumerate all devices
Return PDC_OK when device registration fails so that we enumerate all
subsequent devices, even when we get two devices with the same hardware
path (which should never happen, but does with at least one revision of
rp8400 firmware).

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:33:29 -05:00
Carlos O'Donell
aa0eecb07f [PARISC] Document some register usages in assembly files
Document clobbers and args in entry.S and syscall.S.

entry.S: Add comment to indicate that cr27 may recycle and EDEADLOCK
detection is not 100% correct. Since this is only enabled when using
ENABLE_LWS_DEBUG, the user is warned by the comment.

Signed-off-by: Carlos O'Donell <carlos@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:32:46 -05:00
Ryan Bradetich
75be99a8c5 [PARISC] Make redirecting irq messages less noisy
Make the "redirecting irq" message to not display on the console by
setting the severity to KERN_DEBUG.  The console was basically unusable.

Signed-off-by: Ryan Bradetich <rbrad@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:29:50 -05:00
Grant Grundler
03afe22f07 [PARISC] irq_affinityp[] only available for SMP builds
irq_affinityp[] only available for SMP builds, make code that uses
it conditional on CONFIG_SMP.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:29:16 -05:00
James Bottomley
c2ab64d098 [PARISC] Add IRQ affinities
This really only adds them for the machines I can check SMP on, which
is CPU interrupts and IOSAPIC (so not any of the GSC based machines).

With this patch, irqbalanced can be used to maintain irq balancing.
Unfortunately, irqbalanced is a bit x86 centric, so it doesn't do an
incredibly good job, but it does work.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:28:37 -05:00
Kyle McMartin
1d4c452a85 [PARISC] Fix uniprocessor build by dummying smp_send_all_nop()
Since irq.c uses smp_send_all_nop, we must define it for UP builds
as well. Make it a static inline so it gets optimized away. This forces
irq.c to include <asm/smp.h> though.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:27:44 -05:00
James Bottomley
d911aed8ad [PARISC] Fix our interrupts not to use smp_call_function
Fix our interrupts not to use smp_call_function

On K and D class smp, the generic code calls this under an irq
spinlock, which causes the WARN_ON() message in smp_call_function()
(and is also illegal because it could deadlock).

The fix is to use a new scheme based on the IPI_NOP.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:27:02 -05:00
Grant Grundler
3f902886a8 [PARISC] Disable nesting of interrupts
Disable nesting of interrupts - still has holes

The offending sequence starts out like this:
1) take external interrupt
2) set_eiem() to only allow TIMER_IRQ; local interrupts still disabled
3) read the EIRR to get a "list" of pending interrupts
4) clear EIRR of pending interrupts we intend to handle
5) call __do_IRQ() to handle IRQ.
6) handle_IRQ_event() enables local interrupts (I-Bit)
7) take a timer interrupt
8) read EIRR to get a new list of pending interrupts
9) clear EIRR of pending interrupts we just read
10) handle pending interrupts found in (8)
11) set_eiem(cpu_eiem) and return
        [ TROUBLE! all enabled CPU IRQs are unmasked. }
12) handle remaining interrupts pending from (3)
        e.g. call __do_IRQ() -> handle_IRQ_event()..etc
        [ TROUBLE! call to handle_IRQ_event() can now enable *any* IRQ. }
13) set_eiem(cpu_eiem) and return

The problem is we now get into ugly race conditions with Timer and IPI
interrupts at this point.  I'm not exactly sure what happens when
things go wrong (perhaps nest calls to IPI or timer interrupt?).
But I'm certain it's not good.

This sequence will break sooner if (10) would accidentally leave
interrupts enabled.

I'm pretty sure the right answer is now to make cpu_eiem
a per CPU variable since all external interrupts on parisc
are per CPU. This means we will NOT need to send an IPI to
every CPU in the system when enabling or disabling an IRQ
since only one CPU needs to change it's EIEM.

Thanks to James Bottomley for (once again) pointing out the problem.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:26:20 -05:00
James Bottomley
9a8b458406 [PARISC] Make sure timer and IPI execute with interrupts disabled
Fix a longstanding smp bug

The problem is that both the timer and ipi interrupts are being called
with interrupts enabled, which isn't what anyone is expecting.

The IPI issue has just started to show up by causing a BUG_ON in the
slab debugging code.  The timer issue never shows up because there's an
eiem work around in our irq.c

The fix is to label both these as SA_INTERRUPT which causes the generic
irq code not to enable interrupts.

I also suspect the smp_call_function timeouts we're seeing might be
connected with the fact that we disable IPIs when handling any other
type of interrupt.  I've put a WARN_ON in the code for executing
smp_call_function() with IPIs disabled.

Signed-off-by: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-11-17 16:24:52 -05:00
Nick Piggin
64c7c8f885 [PATCH] sched: resched and cpu_idle rework
Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce
confusion, and make their semantics rigid.  Improves efficiency of
resched_task and some cpu_idle routines.

* In resched_task:
- TIF_NEED_RESCHED is only cleared with the task's runqueue lock held,
  and as we hold it during resched_task, then there is no need for an
  atomic test and set there. The only other time this should be set is
  when the task's quantum expires, in the timer interrupt - this is
  protected against because the rq lock is irq-safe.

- If TIF_NEED_RESCHED is set, then we don't need to do anything. It
  won't get unset until the task get's schedule()d off.

- If we are running on the same CPU as the task we resched, then set
  TIF_NEED_RESCHED and no further action is required.

- If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set
  after TIF_NEED_RESCHED has been set, then we need to send an IPI.

Using these rules, we are able to remove the test and set operation in
resched_task, and make clear the previously vague semantics of
POLLING_NRFLAG.

* In idle routines:
- Enter cpu_idle with preempt disabled. When the need_resched() condition
  becomes true, explicitly call schedule(). This makes things a bit clearer
  (IMO), but haven't updated all architectures yet.

- Many do a test and clear of TIF_NEED_RESCHED for some reason. According
  to the resched_task rules, this isn't needed (and actually breaks the
  assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock
  held). So remove that. Generally one less locked memory op when switching
  to the idle thread.

- Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner
  most polling idle loops. The above resched_task semantics allow it to be
  set until before the last time need_resched() is checked before going into
  a halt requiring interrupt wakeup.

  Many idle routines simply never enter such a halt, and so POLLING_NRFLAG
  can be always left set, completely eliminating resched IPIs when rescheduling
  the idle task.

  POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:56:33 -08:00
Nick Piggin
5bfb5d690f [PATCH] sched: disable preempt in idle tasks
Run idle threads with preempt disabled.

Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
How did it ever work before?

Might fix the CPU hotplugging hang which Nigel Cunningham noted.

We think the bug hits if the idle thread is preempted after checking
need_resched() and before going to sleep, then the CPU offlined.

After calling stop_machine_run, the CPU eventually returns from preemption and
into the idle thread and goes to sleep.  The CPU will continue executing
previous idle and have no chance to call play_dead.

By disabling preemption until we are ready to explicitly schedule, this bug is
fixed and the idle threads generally become more robust.

From: alexs <ashepard@u.washington.edu>

  PPC build fix

From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>

  MIPS build fix

Signed-off-by: Nick Piggin <npiggin@suse.de>
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>
2005-11-09 07:56:33 -08:00
Olaf Hering
733482e445 [PATCH] changing CONFIG_LOCALVERSION rebuilds too much, for no good reason
This patch removes almost all inclusions of linux/version.h.  The 3
#defines are unused in most of the touched files.

A few drivers use the simple KERNEL_VERSION(a,b,c) macro, which is
unfortunatly in linux/version.h.

There are also lots of #ifdef for long obsolete kernels, this was not
touched.  In a few places, the linux/version.h include was move to where
the LINUX_VERSION_CODE was used.

quilt vi `find * -type f -name "*.[ch]"|xargs grep -El '(UTS_RELEASE|LINUX_VERSION_CODE|KERNEL_VERSION|linux/version.h)'|grep -Ev '(/(boot|coda|drm)/|~$)'`

search pattern:
/UTS_RELEASE\|LINUX_VERSION_CODE\|KERNEL_VERSION\|linux\/\(utsname\|version\).h

Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-09 07:55:57 -08:00
Christoph Hellwig
481bed4542 [PATCH] consolidate sys_ptrace()
The sys_ptrace boilerplate code (everything outside the big switch
statement for the arch-specific requests) is shared by most architectures.
This patch moves it to kernel/ptrace.c and leaves the arch-specific code as
arch_ptrace.

Some architectures have a too different ptrace so we have to exclude them.
They continue to keep their implementations.  For sh64 I had to add a
sh64_ptrace wrapper because it does some initialization on the first call.
For um I removed an ifdefed SUBARCH_PTRACE_SPECIAL block, but
SUBARCH_PTRACE_SPECIAL isn't defined anywhere in the tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:53:42 -08:00
Thomas Gleixner
ecea8d19c9 [PATCH] jiffies_64 cleanup
Define jiffies_64 in kernel/timer.c rather than having 24 duplicated
defines in each architecture.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:25 -08:00
Christoph Hellwig
7024a9b884 [PATCH] adjust parisc sys_ptrace prototype
Make the pid argument a long as on every other arcihtecture.  Despite pid_t
beeing a 32bit type even on 64bit parisc this is not an ABI change due to
the parisc calling conventions.  And even if it did it wouldn't matter too
much because 64bit userspace on parisc is in an embrionic stage.

Acked-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:20 -08:00
Christoph Hellwig
9c0cbd54ce [PATCH] TIOC* compat ioctl handling
TIOCSTART and TIOCSTOP are defined in asm/ioctls.h and asm/termios.h by
various architectures but not actually implemented anywhere but in the IRIX
compatibility layer, so remove their COMPATIBLE_IOCTL from parisc, ppc64
and sparc64.

Move the TIOCSLTC COMPATIBLE_IOCTL to common code, guided by an ifdef to
only show up on architectures that support it (same as the code handling it
in tty_ioctl.c), aswell as it's brother TIOCGLTC that wasn't handled so
far.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:17 -08:00
Hugh Dickins
92dc6fcc84 [PATCH] mm: parisc pte atomicity
There's a worrying function translation_exists in parisc cacheflush.h,
unaffected by split ptlock since flush_dcache_page is using it on some other
mm, without any relevant lock.  Oh well, make it a slightly more robust by
factoring the pfn check within it.  And it looked liable to confuse a
camouflaged swap or file entry with a good pte: fix that too.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 21:40:42 -07:00