Commit Graph

56 Commits

Author SHA1 Message Date
Thomas Bogendoerfer
5a334fa924 [MIPS] IP22: Use common SGI button driver
Use the Indy/O2 button driver.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-07-20 14:38:18 +01:00
Thomas Bogendoerfer
b03d7b18fd [MIPS] IP22: Add platform device for Indy volume buttons
Create platform device for Indy volume buttons and remove button
handling from ip22-reset.c

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-07-15 18:44:37 +01:00
Thomas Bogendoerfer
5b438c4408 [MIPS] IP22/28: Add platform devices for HAL2
Create platform devices for hal2 and add option for selecting HAL2 alsa
driver.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-07-15 18:44:36 +01:00
Thomas Bogendoerfer
7a2852e49f [MIPS] IP28: switch to "normal" mode after PROM no longer needed
SGI-IP28 is running in so called slow mode, when kernel is started
from the PROM. PROM calls must be done in slow mode otherwise the
PROM will issue an error. To get better memory performance we now
switch to normal mode, when the PROM is no longer needed.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-07-15 18:44:32 +01:00
Robert P. J. Day
52f4f6bbcf [MIPS] Use kernel-supplied ARRAY_SIZE() macro.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-07-15 18:44:30 +01:00
Thomas Bogendoerfer
e2defae5a9 [MIPS] IP28 support
Add support for SGI IP28 machines (Indigo 2 with R10k CPUs)
This work is mainly based on Peter Fuersts work.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:58 +00:00
Thomas Bogendoerfer
68576cf122 IP22ZILOG: fix lockup and sysrq
- fix lockup when switching from early console to real console
 - make sysrq reliable
 - fix panic, if sysrq is issued before console is opened

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-29 09:24:53 -08:00
Thomas Bogendoerfer
5b3af8f19f [MIPS] IP22: Fix broken eeprom access by using __raw_readl/__raw_writel
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-11-26 17:26:14 +00:00
Thomas Bogendoerfer
68de480372 [MIPS] IP22: Fix broken EISA interrupt setup by switching to generic i8259
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-11-26 17:26:14 +00:00
Thomas Bogendoerfer
0eafaae84e [MIPS] IP22: Fix hang due to messing with timer interrupt handler
As IP22 is now using do_IRQ for timer interrupt, don't mess with
interrupt handler any longer

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-17 18:28:49 +01:00
Ralf Baechle
1c5dc03401 [MIPS] IP22: Enable -Werror.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-16 18:23:47 +01:00
Ralf Baechle
754d0f239d [MIPS] IP22: Complain if requesting the front panel irq failed.
This fixes the warning:

  CC      arch/mips/sgi-ip22/ip22-reset.o
arch/mips/sgi-ip22/ip22-reset.c: In function 'reboot_setup':
arch/mips/sgi-ip22/ip22-reset.c:239: warning: ignoring return value of 'request_irq', declared with attribute warn_unused_result

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-16 18:23:46 +01:00
Ralf Baechle
49a89efbbb [MIPS] Fix "no space between function name and open parenthesis" warnings.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:15 +01:00
Ralf Baechle
d865bea4da [MIPS] i8253 PIT clocksource and clockevent drivers
Derived from the i386 variant with a few x86 complexities chopped off.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:10 +01:00
Ralf Baechle
7bcf7717b6 [MIPS] Implement clockevents for R4000-style cp0 count/compare interrupt
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:09 +01:00
Ralf Baechle
91a2fcc886 [MIPS] Consolidate all variants of MIPS cp0 timer interrupt handlers.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:09 +01:00
Ralf Baechle
90b02340dc [MIPS] Switch from to_tm to rtc_time_to_tm
This replaces the MIPS-specific to_tm function with the generic
rtc_time_to_tm function.  The big difference between the two functions is
that rtc_time_to_tm uses epoch 70 while to_tm uses 1970, so the result of
rtc_time_to_tm needs to be fixed up.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:09 +01:00
Ralf Baechle
4b550488f8 [MIPS] Deforest the function pointer jungle in the time code.
Hard to follow who is pointing what to where and why so it's simply getting
in the way of the time code renovation.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-11 23:46:08 +01:00
Thomas Bogendoerfer
01e9943c79 [MIPS] IP22: fix wrong argument order
Fix wrong argument order; this is just a minimal fix for the half baked
redadb/writeb() conversion.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-09-11 19:03:26 +01:00
Thomas Bogendoerfer
0ba8bc60ca [MIPS] IP22: Fix wrong check for second HPC
Wrong check for the second hpc on fullhouse machines, caused DBEs on
SGI Indys

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-09-11 19:03:26 +01:00
Ralf Baechle
88eb4134b0 [MIPS] IP22: Export sgi_gfxaddr for use by the Newport console driver.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-08-27 02:16:59 +01:00
Ralf Baechle
5bd080f7d2 [MIPS] IP22: Fix modpost warning.
MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0xc70): Section mismatch: reference to .init.text:add_memory_region (between 'probe_memory' and 'enable_local0_irq')

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-08-27 02:16:56 +01:00
Robert P. J. Day
b3f6df9f21 [MIPS] Transform old-style macros to newer "__noreturn"
Convert old/obsolete NORET_TYPE and ATTRIB_NORET macros to use the
newer standard of "__noreturn" as defined in compiler-gcc.h.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-10 17:32:56 +01:00
Ralf Baechle
df9f54084f Convert SGI IP22 and specific drivers to platform_device.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-05-11 17:00:29 +01:00
Ralf Baechle
78709b9df3 [MIPS] IP22: Get rid of volatile in IP22 core code.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-27 16:20:23 +01:00
Thiemo Seufer
119537c092 [MIPS] Misc fixes for plat_irq_dispatch functions
o adds missing ST0_IM masks, which caused the logging of valid interrupts
   as spurious
 o stops pnx8550 to log every interrupt as spurious
 o adds cause register masks for ip22/ip32, which caused handling of masked
   interrupts
 o removes some superfluous parentheses in the SNI interrupt code

Signed-Off-By: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-19 20:22:43 +00:00
Atsushi Nemoto
d2af363cfb [MIPS] Kill redundant EXTRA_AFLAGS
Many Makefiles in arch/mips have EXTRA_AFLAGS := $(CFLAGS) line.  This
is redundant while AFLAGS contains $(cflags-y) and any options only
listed in CFLAGS (not in cflags-y) should be unnecessary for asm
sources.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-26 23:06:05 +00:00
Atsushi Nemoto
70d21cdeef [MIPS] use name instead of typename for each irq_chip
The "typename" field was obsoleted by the "name" field.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-06 16:53:14 +00:00
Atsushi Nemoto
c44e8d5e47 [MIPS] prom_free_prom_memory cleanup
Current prom_free_prom_memory() implementations are almost same as
free_init_pages(), or no-op.  Make free_init_pages() extern (again)
and make prom_free_prom_memory() use it.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-06 16:53:09 +00:00
Atsushi Nemoto
97dcb82de6 [MIPS] Define MIPS_CPU_IRQ_BASE in generic header
The irq_base for {mips,rm7k,rm9k}_cpu_irq_init() are constant on all
platforms and are same value on most platforms (0 or 16, depends on
CONFIG_I8259).  Define them in asm-mips/mach-generic/irq.h and make
them customizable.  This will save a few cycle on each CPU interrupt.

A good side effect is removing some dependencies to MALTA in generic
SMTC code.

Although MIPS_CPU_IRQ_BASE is customizable, this patch changes irq
mappings on DDB5477, EMMA2RH and MIPS_SIM, since really customizing
them might cause some header dependency problem and there seems no
good reason to customize it.  So currently only VR41XX is using custom
MIPS_CPU_IRQ_BASE value, which is 0 regardless of CONFIG_I8259.

Testing this patch on those platforms is greatly appreciated.  Thank
you.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-02-06 16:53:08 +00:00
Franck Bui-Huu
e77c232cfc [MIPS] Compile __do_IRQ() when really needed
__do_IRQ() is needed only by irq handlers that can't use
default handlers defined in kernel/irq/chip.c.

For others platforms there's no need to compile this function
since it won't be used. For those platforms this patch defines
GENERIC_HARDIRQS_NO__DO_IRQ symbol which is used exactly for
this purpose.

Futhermore for platforms which do not use __do_IRQ(), end()
method which is part of the 'irq_chip' structure is not used.
This patch simply removes this method in this case.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-12-06 20:16:08 +00:00
Atsushi Nemoto
1417836e81 [MIPS] use generic_handle_irq, handle_level_irq, handle_percpu_irq
Further incorporation of generic irq framework.  Replacing __do_IRQ()
by proper flow handler would make the irq handling path a bit simpler
and faster.

* use generic_handle_irq() instead of __do_IRQ().
* use handle_level_irq for obvious level-type irq chips.
* use handle_percpu_irq for irqs marked as IRQ_PER_CPU.
* setup .eoi routine for irq chips possibly used with handle_percpu_irq.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-30 01:14:46 +00:00
Atsushi Nemoto
1603b5aca4 [MIPS] IRQ cleanups
This is a big irq cleanup patch.

* Use set_irq_chip() to register irq_chip.
* Initialize .mask, .unmask, .mask_ack field.  Functions for these
  method are already exist in most case.
* Do not initialize .startup, .shutdown, .enable, .disable fields if
  default routines provided by irq_chip_set_defaults() were suitable.
* Remove redundant irq_desc initializations.
* Remove unnecessary local_irq_save/local_irq_restore, spin_lock.

With this cleanup, it would be easy to switch to slightly lightwait
irq flow handlers (handle_level_irq(), etc.) instead of __do_IRQ().

Though whole this patch is quite large, changes in each irq_chip are
not quite simple.  Please review and test on your platform.  Thanks.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-30 01:14:46 +00:00
Ralf Baechle
937a801576 [MIPS] Complete fixes after removal of pt_regs argument to int handlers.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-10-08 02:38:28 +01:00
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Cedric Le Goater
9ec52099e4 [PATCH] replace cad_pid by a struct pid
There are a few places in the kernel where the init task is signaled.  The
ctrl+alt+del sequence is one them.  It kills a task, usually init, using a
cached pid (cad_pid).

This patch replaces the pid_t by a struct pid to avoid pid wrap around
problem.  The struct pid is initialized at boot time in init() and can be
modified through systctl with

	/proc/sys/kernel/cad_pid

[ I haven't found any distro using it ? ]

It also introduces a small helper routine kill_cad_pid() which is used
where it seemed ok to use cad_pid instead of pid 1.

[akpm@osdl.org: cleanups, build fix]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:25 -07:00
Julien BLACHE
d1d60ded2b [MIPS] IP22 Fix brown paper bag in RTC code.
This patch fixes a typo in arch/mips/sgi-ip22/ip22-time.c, leading to the
incorrect year being set into the RTC chip.

Signed-off-by: Julien BLACHE <jb@jblache.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-07-13 21:26:18 +01:00
Ralf Baechle
54d0a216f4 [MIPS] Replace board_timer_setup function pointer by plat_timer_setup.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

---
2006-07-13 21:26:17 +01:00
Ralf Baechle
046f8f705b [MIPS] Remove redeclarations of setup_irq().
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-07-13 21:26:16 +01:00
Ralf Baechle
94dee171df [MIPS] Eleminate interrupt migration helper use.
> #define hw_interrupt_type       irq_chip
> typedef struct irq_chip         hw_irq_controller;
> #define no_irq_type             no_irq_chip
> typedef struct irq_desc         irq_desc_t;

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-07-13 21:25:58 +01:00
Thomas Gleixner
f40298fddc [PATCH] irq-flags: MIPS: Use the new IRQF_ constants
Use the new IRQF_ constants and remove the SA_INTERRUPT define

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:47 -07:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Ingo Molnar
d1bef4ed5f [PATCH] genirq: rename desc->handler to desc->chip
This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.

While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.

The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.

This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.

As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.

The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.

We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.

This patch:

rename desc->handler to desc->chip.

Originally i did not want to do this, because it's a big patch.  But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.

I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.

So lets get over with this quickly.  The conversion was done automatically
via scripts and converts all the code in the kernel.

This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.

[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 10:26:21 -07:00
Lee Revell
f18190bd34 fix paniced->panicked typos
In a testament to the utter simplicity and logic of the English
language ;-), I found a single correct use - in kernel/panic.c - and
10-15 incorrect ones.

Signed-Off-By: Lee Revell <rlrevell@joe-job.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26 18:30:00 +02:00
Ralf Baechle
2925aba422 [MIPS] Cleanup memory managment initialization.
Historically plat_mem_setup did the entire platform initialization.  This
was rather impractical because it meant plat_mem_setup had to get away
without any kind of memory allocator.  To keep old code from breaking
plat_setup was just renamed to plat_setup and a second platform
initialization hook for anything else was introduced.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-19 17:39:23 +01:00
Ralf Baechle
e4ac58afdf [MIPS] Rewrite all the assembler interrupt handlers to C.
Saves like 1,600 lines of code, is way easier to debug, compilers
frequently do a better job than the cut and paste type of handlers many
boards had.  And finally having all the stuff done in a single place
also means alot of bug potencial for the MT ASE is gone.

The only surviving handler in assembler is the DECstation one; I hope
Maciej will rewrite it.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-04-19 04:14:21 +02:00
Yoichi Yuasa
d23ee8fe6e [PATCH] mips: fixed collision of rtc function name
Fix the collision of rtc function name.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 08:44:50 -08:00
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
Ralf Baechle
e9feeb207e [MIPS] IP22: Fix serial console detection
From: Kaj-Michael Lang <milang@tal.org>
    
In ip22-setup.c the checks for serial/graphics console logic does
not check if ARCS console=g but the machine is using serial console, as
it does if no keyboard is attached.
    
This patch adds a check if ConsoleOut is serial. There might also be
support for other graphics than Newport soon...
    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-07 13:30:25 +00:00
Ralf Baechle
fcdb27ad1d [MIPS] Rename _machine_power_off to pm_power_off so the kernel builds again.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-02-07 13:30:22 +00:00