Commit Graph

17 Commits

Author SHA1 Message Date
Toshi Kani 6dedcca610 hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock()
cpu_hotplug_driver_lock() serializes CPU online/offline operations
when ARCH_CPU_PROBE_RELEASE is set.  This lock interface is no longer
necessary with the following reason:

 - lock_device_hotplug() now protects CPU online/offline operations,
   including the probe & release interfaces enabled by
   ARCH_CPU_PROBE_RELEASE.  The use of cpu_hotplug_driver_lock() is
   redundant.
 - cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE
   is defined, which is misleading and is only enabled on powerpc.

This patch removes the cpu_hotplug_driver_lock() interface.  As
a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu
probe & release interface as intended.  There is no functional change
in this patch.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-30 19:55:51 +02:00
Toshi Kani 574b851e99 hotplug / x86: Add hotplug lock to missing places
lock_device_hotplug[_sysfs]() serializes CPU & Memory online/offline
and hotplug operations.  However, this lock is not held in the debug
interfaces below that initiate CPU online/offline operations.

 - _debug_hotplug_cpu(), cpu0 hotplug test interface enabled by
   CONFIG_DEBUG_HOTPLUG_CPU0.
 - cpu_probe_store() and cpu_release_store(), cpu hotplug test interface
   enabled by CONFIG_ARCH_CPU_PROBE_RELEASE.

This patch changes the above interfaces to hold lock_device_hotplug().

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-25 10:38:09 +02:00
Toshi Kani f6913f9902 hotplug / x86: Fix online state in cpu0 debug interface
_debug_hotplug_cpu() is a debug interface that puts cpu0 offline during
boot-up when CONFIG_DEBUG_HOTPLUG_CPU0 is set.  After cpu0 is put offline
in this interface, however, /sys/devices/system/cpu/cpu0/online still
shows 1 (online).

This patch fixes _debug_hotplug_cpu() to update dev->offline when CPU
online/offline operation succeeded.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-25 10:38:09 +02:00
Fenghua Yu a71c8bc5df x86, topology: Debug CPU0 hotplug
CONFIG_DEBUG_HOTPLUG_CPU0 is for debugging the CPU0 hotplug feature. The switch
offlines CPU0 as soon as possible and boots userspace up with CPU0 offlined.
User can online CPU0 back after boot time. The default value of the switch is
off.

To debug CPU0 hotplug, you need to enable CPU0 offline/online feature by either
turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during compilation or giving
cpu0_hotplug kernel parameter at boot.

It's safe and early place to take down CPU0 after all hotplug notifiers
are installed and SMP is booted.

Please note that some applications or drivers, e.g. some versions of udevd,
during boot time may put CPU0 online again in this CPU0 hotplug debug mode.

In this debug mode, setup_local_APIC() may report a warning on max_loops<=0
when CPU0 is onlined back after boot time. This is because pending interrupt in
IRR can not move to ISR. The warning is not CPU0 specfic and it can happen on
other CPUs as well. It is harmless except the first CPU0 online takes a bit
longer time. And so this debug mode is useful to expose this issue. I'll send
a seperate patch to fix this generic warning issue.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-15-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-14 15:28:11 -08:00
Fenghua Yu 4d25031a81 x86, topology: Don't offline CPU0 if any PIC irq can not be migrated out of it
If CONFIG_BOOTPARAM_HOTPLUG_CPU is turned on, CPU0 hotplug feature is enabled
by default.

If CONFIG_BOOTPARAM_HOTPLUG_CPU is not turned on, CPU0 hotplug feature is not
enabled by default. The kernel parameter cpu0_hotplug can enable CPU0 hotplug
feature at boot.

Currently the feature is supported on Intel platforms only.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1352835171-3958-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-11-14 09:39:47 -08:00
Paul Gortmaker 69c60c88ee x86: Fix files explicitly requiring export.h for EXPORT_SYMBOL/THIS_MODULE
These files were implicitly getting EXPORT_SYMBOL via device.h
which was including module.h, but that will be fixed up shortly.

By fixing these now, we can avoid seeing things like:

arch/x86/kernel/rtc.c:29: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/pci-dma.c:20: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL’
arch/x86/kernel/e820.c:69: warning: type defaults to ‘int’ in declaration of ‘EXPORT_SYMBOL_GPL’

[ with input from Randy Dunlap <rdunlap@xenotime.net> and also
  from Stephen Rothwell <sfr@canb.auug.org.au> ]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:35 -04:00
Lucas De Marchi 0d2eb44f63 x86: Fix common misspellings
They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:39:30 +01:00
Jaswinder Singh Rajput 271eb5c588 x86: topology.c cleanup
Impact: cleanup

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
2009-03-21 16:55:24 +05:30
Sam Ravnborg 177c7715cd x86: fix section mismatch warning in topology.c:arch_register_cpu
arch_register_cpu() is only defined for HOTPLUG_CPU code
so simple fix is to ignore references by annotating the
function __ref.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-19 16:18:30 +01:00
Harvey Harrison 9583d050d5 x86: fix sparse warning in topology.c
arch/x86/kernel/topology.c:56:2: warning: returning void-valued expression

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-09 23:24:08 +01:00
Alexander van Heukelum d987402695 x86: avoid section mismatch involving arch_register_cpu
Avoid section mismatch involving arch_register_cpu.

Marking arch_register_cpu as __init and removing the export
for non-hotplug-cpu configurations makes the following warning
go away:

Section mismatch in reference from the function
arch_register_cpu() to the function .devinit.text:register_cpu()
The function  arch_register_cpu() references
the function __devinit register_cpu().
This is often because arch_register_cpu lacks a __devinit
annotation or the annotation of register_cpu is wrong.

The only external user of arch_register_cpu in the tree is
in drivers/acpi/processor_core.c where it is guarded by
ACPI_HOTPLUG_CPU (which depends on HOTPLUG_CPU).

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-01 17:49:43 +01:00
Sam Ravnborg 3eaf5efae7 x86: fix section mismatch warning in topology.c
Fix following warning:
WARNING: arch/x86/kernel/built-in.o(__ksymtab+0x2b0): Section mismatch: reference to .cpuinit.text:arch_register_cpu in '__ksymtab_arch_register_cpu'

Annotating exported symbols are wrong.
Previously the warning were hidden by avoiding the export
in the non HOTPLUG_CPU case but the improved checks in
modpost caught it anyway.
Fix it by removing the __cpuinit annotation and rearrange the
code a bit to save one ifdef/endif pair.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:37 +01:00
travis@sgi.com 30964d54e9 x86: change NR_CPUS arrays in topology
Change the following static arrays sized by NR_CPUS to
per_cpu data variables:

	i386_cpu cpu_devices[NR_CPUS];

(And change the struct name to x86_cpu.)

Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:11 +01:00
Andrew Morton da54becc71 x86: arch_register_cpu() section fix
fix this on i386 allnoconfig:

 WARNING: vmlinux.o(.text+0x6f2e): Section mismatch: reference to .init.text:register_cpu (between 'arch_register_cpu' and 'text_poke')

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-12-04 17:19:07 +01:00
Adrian Bunk a850cef77f i386: no need to make enable_cpu_hotplug a variable
As long as there's no write access to this variable there's no reason to
let gcc check it at runtime.

[ tglx: arch/x86 adaptation ]

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-17 20:16:16 +02:00
Dave Jones 835c34a168 Delete filenames in comments.
Since the x86 merge, lots of files that referenced their own filenames
are no longer correct.  Rather than keep them up to date, just delete
them, as they add no real value.

Additionally:
- fix up comment formatting in scx200_32.c
- Remove a credit from myself in setup_64.c from a time when we had no SCM
- remove longwinded history from tsc_32.c which can be figured out from
  git.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-13 10:01:23 -07:00
Thomas Gleixner 9a163ed8e0 i386: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-11 11:17:01 +02:00