Commit Graph

858 Commits

Author SHA1 Message Date
Anton Blanchard 49c28e4e40 [PATCH] powerpc: Avoid __initcall warnings
Fix __initcall return in proc_rtas_init and rtas_init.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-13 09:27:26 -07:00
Anton Blanchard ddafddcfc7 [PATCH] powerpc: Ensure runlatch is off in the idle loop
Since external and decrementer interrupts set the runlatch on, we need
to ensure its set off again in the idle loop. At the moment we dont turn
it off in the inner loop.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-13 09:27:22 -07:00
Paul Mackerras b86756ae76 powerpc: Fix CHRP booting - needs a define_machine call
The patch removing _machine and converting platforms over to use
define_machine wasn't complete as far as CHRP was concerned.  This
adds the define_machine call for CHRP and gets it booting again.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-05 16:01:45 +10:00
Stephen Rothwell 7d01c88085 powerpc: iSeries has only 256 IRQs
The iSeries Hypervisor only allows us to specify IRQ numbers up to 255 (it
has a u8 field to pass it in).  This patch allows platforms to specify a
maximum to the virtual IRQ numbers we will use and has iSeries set that
to 255.  If not set, the maximum is NR_IRQS - 1 (as before).

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2006-04-04 14:49:48 +10:00
Linus Torvalds 9c8680e2cf Merge master.kernel.org:/pub/scm/linux/kernel/git/dtor/input
* master.kernel.org:/pub/scm/linux/kernel/git/dtor/input: (26 commits)
  Input: add support for Braille devices
  Input: synaptics - limit rate to 40pps on Toshiba Protege M300
  Input: gamecon - add SNES mouse support
  Input: make modalias code respect allowed buffer size
  Input: convert /proc handling to seq_file
  Input: limit attributes' output to PAGE_SIZE
  Input: gameport - fix memory leak
  Input: serio - fix memory leak
  Input: zaurus keyboard driver updates
  Input: i8042 - fix logic around pnp_register_driver()
  Input: ns558 - fix logic around pnp_register_driver()
  Input: pcspkr - separate device and driver registration
  Input: atkbd - allow disabling on X86_PC (if EMBEDDED)
  Input: atkbd - disable softrepeat for dumb keyboards
  Input: atkbd - fix complaints about 'releasing unknown key 0x7f'
  Input: HID - fix duplicate key mapping for Logitech UltraX remote
  Input: use kzalloc() throughout the code
  Input: fix input_free_device() implementation
  Input: initialize serio and gameport at subsystem level
  Input: uinput - semaphore to mutex conversion
  ...
2006-04-02 12:49:19 -07:00
Dmitry Torokhov 95d465fd75 Manual merge with Linus.
Conflicts:
	arch/powerpc/kernel/setup-common.c
	drivers/input/keyboard/hil_kbd.c
	drivers/input/mouse/hil_ptr.c
2006-04-02 00:08:05 -05:00
Stephen Rothwell 856d08ec46 [PATCH] powerpc: iSeries needs slb_initialize to be called
Since the powerpc 64k pages patch went in, systems that have SLBs
(like Power4 iSeries) needed to have slb_initialize called to set up
some variables for the SLB miss handler.  This was not being called
on the boot processor on iSeries, so on single cpu iSeries machines,
we would get apparent memory curruption as soon as we entered user mode.

This patch fixes that by calling slb_initialize on the boot cpu if the
processor has an SLB.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-02 09:32:15 +10:00
Paul Mackerras 2c6967750a powerpc: hook up the splice syscall
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 23:27:23 +11:00
Dave Jones cfff5b23ba [PATCH] powerpc/cell: compile fixes
Missing include for __NR_syscalls, and missing sys_splice() that
causes build-time failure due to compile-time bounds check on
spu_syscall_table.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:37:14 +11:00
Anton Blanchard fc5266ea52 [PATCH] powerpc: trivial spelling fixes in fault.c
This comment exceeded my bad spelling threshold :)

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:37:13 +11:00
Nathan Fontenot 794e085e56 [PATCH] powerpc/pseries: EEH Cleanup
This patch removes unnecessary exports, marks functions as static when
possible, and simplifies some list-related code.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:37:11 +11:00
Will Schmidt 34422fed65 [PATCH] powerpc/pseries: misc lparcfg fixes
This fixes several problems with the lparcfg code.  In case
someone gets a sense of deja-vu, part of this was submitted last Sep, I
thought the changes went in, but either got backed out, or just got
lost.

First, change the local_buffer declaration to be unsigned char *.  We
had a bad-math problem in a 2.4 tree which was built with a
"-fsigned-char" parm.  I dont believe we ever build with that parm
now-a-days, but to be safe, I'd prefer the declaration be explicit.

Second, fix a bad math calculation for splpar_strlen.

Third, on the rtas_call for get-system-parameter, pass in
RTAS_DATA_BUF_SIZE for the rtas_data_buf size, instead of letting random
data determine the size.   Until recently, we've had a sufficiently
large 'random data' value get passed in, so the function just happens to
have worked OK.   Now it's getting passed a '0', which causes the
rtas_call to return success, but no data shows up in the buffer.
(oops!).   This was found by the LTC test org.

This is in a branch of code that only gets run on SPLPAR systems.
Tested on power5 Lpar.

Signed-off-by: Will Schmidt <willschm@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:37:07 +11:00
Linas Vepstas a219be2cf4 [PATCH] powerpc/pseries: fix device name printing, again.
The recent patch to print device names in EEH reset messages
was lacking ... this patch works better.

Signed-off-by: Linas Vepstas <linas@linas.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:37:02 +11:00
Heiko J Schick b13a96cfb0 [PATCH] powerpc: Extends HCALL interface for InfiniBand usage
This extends the HCALL interface for InfiniBand usage. I've
made the patch against the linux-2.6 git tree and Segher's patch:
[PATCH] Change H_StudlyCaps to H_SHOUTING_CAPS

We moved this into the common powerpc code based on comments we
got after posting the first eHCA InfiniBand device driver patch.

Signed-off-by: Heiko j Schick <schickhj@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:37:00 +11:00
Segher Boessenkool 706c8c93ba [PATCH] powerpc/pseries: Change H_StudlyCaps to H_SHOUTING_CAPS
Also cleans up some nearby whitespace problems.

Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:36:57 +11:00
Linas Vepstas 8df83028cf [PATCH] powerpc/pseries: print message if EEH recovery fails
The current code prints an ambiguous message if the recovery
of a failed PCI device fails. Give this special case its own
unique message.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:35:01 +11:00
Linas Vepstas 8c33fd11e3 [PATCH] powerpc/pseries: mutex lock to serialize EEH event processing
This forces the processing of EEH PCI events to be serialized,
using a very simple mutex lock. This serialization is required to
avoid races involving additional PCI device failures that may occur
during the recovery phase of a previous failure.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-04-01 22:35:01 +11:00
Paul Mackerras f18dd516d4 Merge branch 'for_paulus' of git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc 2006-04-01 22:08:26 +11:00
Adrian Bunk 0cb3463f04 [PATCH] unexport get_wchan
The only user of get_wchan is the proc fs - and proc can't be built modular.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:19:01 -08:00
OGAWA Hirofumi 9b41046cd0 [PATCH] Don't pass boot parameters to argv_init[]
The boot cmdline is parsed in parse_early_param() and
parse_args(,unknown_bootoption).

And __setup() is used in obsolete_checksetup().

	start_kernel()
		-> parse_args()
			-> unknown_bootoption()
				-> obsolete_checksetup()

If __setup()'s callback (->setup_func()) returns 1 in
obsolete_checksetup(), obsolete_checksetup() thinks a parameter was
handled.

If ->setup_func() returns 0, obsolete_checksetup() tries other
->setup_func().  If all ->setup_func() that matched a parameter returns 0,
a parameter is seted to argv_init[].

Then, when runing /sbin/init or init=app, argv_init[] is passed to the app.
If the app doesn't ignore those arguments, it will warning and exit.

This patch fixes a wrong usage of it, however fixes obvious one only.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:53 -08:00
Jakub Jelinek da2e9e1ff4 [PATCH] Mark unwind info for signal trampolines in vDSOs
Mark unwind info for signal trampolines using the new S augmentation flag
introduced in: http://gcc.gnu.org/PR26208.

GCC 4.2 (or patched earlier GCC) will be able to special case unwinding
through frames right above signal trampolines.  As the augmentations start
with z flag and S is at the very end of the augmentation string, older GCCs
will just skip the S flag as unknown (that's why an augmentation flag was
chosen over say a new CFA opcode).

Signed-off-by: Jakub Jelinek <jakub@redhat.com>
Cc: Andi Kleen <ak@muc.de>
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>
2006-03-31 12:18:52 -08:00
Kumar Gala 72d2c3e038 powerpc: converted embedded platforms to use new define_machine support
Removed platform_init usage on 83xx and 85xx and use define_machine and
probe().  For now we always return true in the problem since you can only
build for one specific board at a time.  This is an artificial constraint.
When we get ride of it we will need to update the Kconfig's for these
sub-arch's and make the board's probe() functions actually do something.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2006-03-30 23:39:57 -06:00
Kumar Gala 1a6a4ffef6 powerpc: merge machine_check_exception between ppc32 & ppc64
Make machine_check_exception handling code path the same on ppc32 & ppc64.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2006-03-30 21:11:15 -06:00
Anton Blanchard 15e812ad84 [PATCH] powerpc: Remove oprofile spinlock backtrace code
Remove oprofile spinlock backtrace code now we have proper calltrace
support. Also make MMCRA sihv and sipr bits a variable since they may
change in future cpus. Finally, MMCRA should be a 64bit quantity.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
Anton Blanchard fa465f8c70 [PATCH] powerpc: Add oprofile calltrace support to all powerpc cpus
Add calltrace support for other powerpc cpus. Tested on 7450.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
Brian Rogan 6c6bd754bf [PATCH] powerpc: Add oprofile calltrace support
Add oprofile calltrace support to powerpc. Disable spinlock backtracing
now we can use calltrace info.

(Updated to work on both 32bit and 64bit by me).

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:16 +11:00
KAMEZAWA Hiroyuki 0e5519548f [PATCH] for_each_possible_cpu: powerpc
for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:15 +11:00
Eugene Surovegin bab70a4af7 [PATCH] lock PTE before updating it in 440/BookE page fault handler
Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.

Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29 13:44:15 +11:00
Paul Mackerras bac30d1a78 Merge ../linux-2.6 2006-03-29 13:24:50 +11:00
Arjan van de Ven 99ac48f54a [PATCH] mark f_ops const in the inode
Mark the f_ops members of inodes as const, as well as fix the
ripple-through this causes by places that copy this f_ops and then "do
stuff" with it.

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:05 -08:00
Matt Mackall 6f0d7bd6a1 [PATCH] RTC: Remove RTC UIP synchronization on PPC Maple
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:00 -08:00
Matt Mackall 4dc12ec7e2 [PATCH] RTC: Remove RTC UIP synchronization on CHRP (arch/powerpc)
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:00 -08:00
Benjamin Herrenschmidt e8222502ee [PATCH] powerpc: Kill _machine and hard-coded platform numbers
This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism.  With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.

We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants.  This commit also
changes various drivers to use the new macro instead of looking at
_machine.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 23:15:54 +11:00
Stephen Rothwell 4d177fbfda [PATCH] powerpc: a couple of trivial compile warning fixes
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 20:40:33 +11:00
Paul Mackerras cf66c897d7 Merge branch '85xx' of git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc 2006-03-28 17:03:19 +11:00
Paul Mackerras facee873de Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc 2006-03-28 17:02:14 +11:00
Kumar Gala 78af90629c powerpc: remove OCP references
OCP isn't used in arch/powerpc and hopefully will never be.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2006-03-27 23:48:37 -06:00
Stephen Rothwell b239cbe957 [PATCH] powerpc: make ISA floppies work again
We used to assume that a DMA mapping request with a NULL dev was for
ISA DMA.  This assumption was broken at some point.  Now we explicitly
pass the detected ISA PCI device in the floppy setup.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:36 +11:00
Anton Blanchard 69ed332498 [PATCH] powerpc: Fix some initcall return values
Non zero initcalls (except for -ENODEV) have started warning at boot.
Fix smt_setup and init_ras_IRQ.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:34 +11:00
Mike Kravetz 9fe901d124 [PATCH] powerpc: Workaround for pSeries RTAS bug
A bug in the RTAS services incorrectly interprets some bits in the CR
when called from the OS.  Specifically, bits in CR4.  The result could
be a firmware crash that also takes down the partition.  A firmware
fix is in the works.  We have seen this situation when performing DLPAR
operations.  As a temporary workaround, clear the CR in enter_rtas().
Note that enter_rtas() will not set any bits in CR4 before calling RTAS.

Also note that the 32 bit version of enter_rtas() should have the same
work around even though the chances of hitting the bug are much smaller
due to the lack of DLPAR on 32 bit kernels.  However, my assembly skills
are a bit rusty and the 32 bit code doesn't seem to follow the conventions
for where things should be saved.  In addition, I don't have a system
to test 32 bit kernels.  Help creating and at least touch testing the
same workaround for 32 bit would be appreciated.

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:33 +11:00
Arnd Bergmann e78b47a590 [PATCH] spufs: fix __init/__exit annotations
spufs_init and spufs_exit should be marked correctly so
they can be removed when not needed.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:30 +11:00
Ryan S. Arnold 45d607ed92 [PATCH] powerpc: hvc_console updates
These are some updates from both Ryan and Arnd for the hvc_console
driver:

The main point is to enable the inclusion of a console driver
for rtas, which is currrently needed for the cell platform.

Also shuffle around some data-type declarations and moves some
functions out of include/asm-ppc64/hvconsole.h and into a new
drivers/char/hvc_console.h file.

Signed-off-by: "Ryan S. Arnold" <rsa@us.ibm.com>
Signed-off-by: Arnd Bergmann <abergman@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:26 +11:00
Laurent MEYER 11089f08d9 [PATCH] powerpc: fix incorrect SA_ONSTACK behaviour for 64-bit processes
*) When setting a sighandler using sigaction() call, if the flag
SA_ONSTACK is set and no alternate stack is provided via sigaltstack(),
the kernel still try to install the alternate stack. This behavior is
the opposite of the one which is documented in Single Unix
Specifications V3.

*) Also when setting an alternate stack using sigaltstack() with the
flag SS_DISABLE, the kernel try to install the alternate stack on
signal delivery.

These two use cases makes the process crash at signal delivery.

This fixes it.

Signed-off-by: Laurent Meyer <meyerlau@fr.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:24 +11:00
Michael Ellerman d0160bf0b3 [PATCH] powerpc: Rename and export ppc64_firmware_features
We need to export ppc64_firmware_features for modules. Before we do that
I think we should probably rename it to powerpc_firmware_features.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:45:20 +11:00
Kumar Gala 9cf8ca3871 powerpc: Make uImage default build output for MPC8540 ADS
When we build for the MPC8540 ADS produce a uImage by default.
Updated the defconfig to reflect this as well.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2006-03-27 23:44:37 -06:00
Kumar Gala 5cd272085b powerpc: move math-emu over to arch/powerpc
Towards the goal of having arch/powerpc not build anything over in arch/ppc
move math-emu over.  Also, killed some references to arch/ppc/ in the
arch/powerpc Makefile which should belong in drivers/ when the particular
sub-arch's move over to arch/powerpc.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2006-03-27 23:43:27 -06:00
Anton Blanchard 2f25194dbe [PATCH] powerpc: export validate_sp for oprofile calltrace
Export validate_sp so we can use it in the oprofile calltrace code.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 16:19:52 +11:00
Kumar Gala 10d713aef2 powerpc: use memparse() for mem= command line parsing
Use memparse() instead of our own code for handling the parsing of mem=

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2006-03-27 18:26:42 -06:00
Paul Mackerras ff2e6d7e27 powerpc: Fix goof in 6xx and POWER4 idle power-save functions
This fixes a mistake I made when editing these functions - when I
took out the interrupt disabling code (because interrupts are now
disabled by the caller) I left the register that is used for the MSR
value to be used during doze/nap uninitialized.  This fixes it.

Also updated some of the comments in idle_power4.S and removed some
code that was copied over from idle_6xx.S but is no longer relevant
(we don't ever clear the CPU_FTR_CAN_NAP bit at runtime for POWER4).

Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-28 09:28:14 +11:00
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