Commit graph

208 commits

Author SHA1 Message Date
Linus Torvalds 84d69848c9 Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek:

 - EXPORT_SYMBOL for asm source by Al Viro.

   This does bring a regression, because genksyms no longer generates
   checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
   working on a patch to fix this.

   Plus, we are talking about functions like strcpy(), which rarely
   change prototypes.

 - Fixes for PPC fallout of the above by Stephen Rothwell and Nick
   Piggin

 - fixdep speedup by Alexey Dobriyan.

 - preparatory work by Nick Piggin to allow architectures to build with
   -ffunction-sections, -fdata-sections and --gc-sections

 - CONFIG_THIN_ARCHIVES support by Stephen Rothwell

 - fix for filenames with colons in the initramfs source by me.

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
  initramfs: Escape colons in depfile
  ppc: there is no clear_pages to export
  powerpc/64: whitelist unresolved modversions CRCs
  kbuild: -ffunction-sections fix for archs with conflicting sections
  kbuild: add arch specific post-link Makefile
  kbuild: allow archs to select link dead code/data elimination
  kbuild: allow architectures to use thin archives instead of ld -r
  kbuild: Regenerate genksyms lexer
  kbuild: genksyms fix for typeof handling
  fixdep: faster CONFIG_ search
  ia64: move exports to definitions
  sparc32: debride memcpy.S a bit
  [sparc] unify 32bit and 64bit string.h
  sparc: move exports to definitions
  ppc: move exports to definitions
  arm: move exports to definitions
  s390: move exports to definitions
  m68k: move exports to definitions
  alpha: move exports to actual definitions
  x86: move exports to actual definitions
  ...
2016-10-14 14:26:58 -07:00
Daniel Axtens 0545d5436a powerpc/sparse: Add more assembler prototypes
Another set of things that are only called from assembler and so need
prototypes to keep sparse happy.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-13 17:36:58 +10:00
Al Viro 9445aa1a30 ppc: move exports to definitions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:50:09 -04:00
Linus Torvalds 6c84239d59 RTC for 4.8
Cleanups:
  - huge cleanup of rtc-generic and char/genrtc this allowed to cleanup rtc-cmos,
   rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
  - move mn10300 to rtc-cmos
 
 Subsystem:
  - fix wakealarms after hibernate
  - multiples fixes for rctest
  - simplify implementations of .read_alarm
 
 New drivers:
  - Maxim MAX6916
 
 Drivers:
  - ds1307: fix weekday
  - m41t80: add wakeup support
  - pcf85063: add support for PCF85063A variant
  - rv8803: extend i2c fix and other fixes
  - s35390a: fix alarm reading, this fixes instant reboot after shutdown for QNAP
    TS-41x
  - s3c: clock fixes
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABCgAGBQJXokhIAAoJENiigzvaE+LCZqQP+wWzintN/N1u3dKiVB7iSdwq
 +S/jAXD9wW8OK9PI60/YUGRYeUXmZW9t4XYg1VKCxU9KpVC17LgOtDyXD8BufP1V
 uREJEzZw9O7zCCjeHp/ICFjBkc62Net6ZDOO+ZyXPNfddpS1Xq1uUgXLZc/202UR
 ID/kewu0pJRDnoxyqznWn9+8D33w/ygXs2slY2Ive0ONtjdgxGcsj2rNbb2RYn2z
 OP7br3lLg7qkFh4TtXb61eh/9GYIk6wzP/CrX5l/jH4SjQnrIk5g/X/Cd1qQ/qso
 JZzFoonOKvIp5Gw/+fZ9NP3YFcnkoRMv4NjZV8PAmsYLds+ibRiBcoB8u6FmiJV7
 WW5uopgPkfCGN5BV3+QHwJDVe+WlgnlzaT5zPUCcP5KWusDts4fWIgzP7vrtAzf4
 3OJLrgSGdBeOqWnJD21nxKUD27JOseX7D+BFtwxR4lMsXHqlHJfETpZ8gts1ZGH3
 2U353j/jkZvGWmc6dMcuxOXT2K4VqpYeIIqs0IcLu6hM9crtR89zPR2Iu1AilfDW
 h2NroF+Q//SgMMzWoTEG6Tn7RAc7MthgA/tRCFZF9CBMzNs988w0CTHnKsIHmjpU
 UKkMeJGAC9YrPYIcqrg0oYsmLUWXc8JuZbGJBnei3BzbaMTlcwIN9qj36zfq6xWc
 TMLpbWEoIsgFIZMP/hAP
 =rpGB
 -----END PGP SIGNATURE-----

Merge tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "RTC for 4.8

  Cleanups:
   - huge cleanup of rtc-generic and char/genrtc this allowed to cleanup
     rtc-cmos, rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
   - move mn10300 to rtc-cmos

  Subsystem:
   - fix wakealarms after hibernate
   - multiples fixes for rctest
   - simplify implementations of .read_alarm

  New drivers:
   - Maxim MAX6916

  Drivers:
   - ds1307: fix weekday
   - m41t80: add wakeup support
   - pcf85063: add support for PCF85063A variant
   - rv8803: extend i2c fix and other fixes
   - s35390a: fix alarm reading, this fixes instant reboot after
     shutdown for QNAP TS-41x
   - s3c: clock fixes"

* tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (65 commits)
  rtc: rv8803: Clear V1F when setting the time
  rtc: rv8803: Stop the clock while setting the time
  rtc: rv8803: Always apply the I²C workaround
  rtc: rv8803: Fix read day of week
  rtc: rv8803: Remove the check for valid time
  rtc: rv8803: Kconfig: Indicate rx8900 support
  rtc: asm9260: remove .owner field for driver
  rtc: at91sam9: Fix missing spin_lock_init()
  rtc: m41t80: add suspend handlers for alarm IRQ
  rtc: m41t80: make it a real error message
  rtc: pcf85063: Add support for the PCF85063A device
  rtc: pcf85063: fix year range
  rtc: hym8563: in .read_alarm set .tm_sec to 0 to signal minute accuracy
  rtc: explicitly set tm_sec = 0 for drivers with minute accurancy
  rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()
  rtc: s3c: Remove unnecessary call to disable already disabled clock
  rtc: abx80x: use devm_add_action_or_reset()
  rtc: m41t80: use devm_add_action_or_reset()
  rtc: fix a typo and reduce three empty lines to one
  rtc: s35390a: improve two comments in .set_alarm
  ...
2016-08-05 09:48:22 -04:00
Christophe Leroy c223c90386 powerpc32: provide VIRT_CPU_ACCOUNTING
This patch provides VIRT_CPU_ACCOUTING to PPC32 architecture.
PPC32 doesn't have the PACA structure, so we use the task_info
structure to store the accounting data.

In order to reuse on PPC32 the PPC64 functions, all u64 data has
been replaced by 'unsigned long' so that it is u32 on PPC32 and
u64 on PPC64

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
2016-07-09 01:43:50 -05:00
Oliver O'Halloran 7990102446 powerpc/timer: Large Decrementer support
Power ISAv3 adds a large decrementer (LD) mode which increases the size
of the decrementer register. The size of the enlarged decrementer
register is between 32 and 64 bits with the exact size being dependent
on the implementation. When in LD mode, reads are sign extended to 64
bits and a decrementer exception is raised when the high bit is set (i.e
the value goes below zero). Writes however are truncated to the physical
register width so some care needs to be taken to ensure that the high
bit is not set when reloading the decrementer. This patch adds support
for using the LD inside the host kernel on processors that support it.

When LD mode is supported firmware will supply the ibm,dec-bits property
for CPU nodes to allow the kernel to determine the maximum decrementer
value. Enabling LD mode is a hypervisor privileged operation so the kernel
can only enable it manually when running in hypervisor mode. Guests that
support LD mode can request it using the "ibm,client-architecture-support"
firmware call (not implemented in this patch) or some other platform
specific method. If this property is not supplied then the traditional
decrementer width of 32 bit is assumed and LD mode will not be enabled.

This patch was based on initial work by Jack Miller.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 23:58:53 +10:00
Arnd Bergmann 169047f447 rtc: powerpc: provide rtc_class_ops directly
The rtc-generic driver provides an architecture specific
wrapper on top of the generic rtc_class_ops abstraction,
and powerpc has another abstraction on top, which is a bit
silly.

This changes the powerpc rtc-generic device to provide its
rtc_class_ops directly, to reduce the number of layers
by one.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-06-04 00:23:34 +02:00
Daniel Axtens 7f92bc5694 powerpc: sparse: Include headers for __weak symbols
Sometimes when sparse warns about undefined symbols, it isn't
because they should have 'static' added, it's because they're
overriding __weak symbols defined elsewhere, and the header has
been missed.

Fix a few of them by adding appropriate headers.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-12 21:05:19 +10:00
Daniel Axtens 00b912b0c8 powerpc: Remove broken GregorianDay()
GregorianDay() is supposed to calculate the day of the week
(tm->tm_wday) for a given day/month/year. In that calcuation it
indexed into an array called MonthOffset using tm->tm_mon-1. However
tm_mon is zero-based, not one-based, so this is off-by-one. It also
means that every January, GregoiranDay() will access element -1 of
the MonthOffset array.

It also doesn't appear to be a correct algorithm either: see in
contrast kernel/time/timeconv.c's time_to_tm function.

It's been broken forever, which suggests no-one in userland uses
this. It looks like no-one in the kernel uses tm->tm_wday either
(see e.g. drivers/rtc/rtc-ds1305.c:319).

tm->tm_wday is conventionally set to -1 when not available in
hardware so we can simply set it to -1 and drop the function.
(There are over a dozen other drivers in drivers/rtc that do
this.)

Found using UBSAN.

Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org> # as an example of what UBSan finds.
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: rtc-linux@googlegroups.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-16 12:54:04 +11:00
Viresh Kumar 37a13e78e0 powerpc/time: Migrate to new 'set-state' interface
Migrate powerpc driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

We weren't doing anything in ->set_mode(ONSHOT) and so
set_state_oneshot() isn't implemented.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:41:02 +02:00
Paul Gortmaker 8f6b9512ce powerpc: use device_initcall for registering rtc devices
Currently these two RTC devices are in core platform code
where it is not possible for them to be modular.  It will
never be modular, so using module_init as an alias for
__initcall can be somewhat misleading.

Fix this up now, so that we can relocate module_init from
init.h into module.h in the future.  If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.

Note that direct use of __initcall is discouraged, vs. one
of the priority categorized subgroups.  As __initcall gets
mapped onto device_initcall, our use of device_initcall
directly in this change means that the runtime impact is
zero -- they will remain at level 6 in initcall ordering.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Geoff Levand <geoff@infradead.org>
Acked-by: Geoff Levand <geoff@infradead.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2015-06-16 14:12:29 -04:00
Paul Mackerras b6c295df31 KVM: PPC: Book3S HV: Accumulate timing information for real-mode code
This reads the timebase at various points in the real-mode guest
entry/exit code and uses that to accumulate total, minimum and
maximum time spent in those parts of the code.  Currently these
times are accumulated per vcpu in 5 parts of the code:

* rm_entry - time taken from the start of kvmppc_hv_entry() until
  just before entering the guest.
* rm_intr - time from when we take a hypervisor interrupt in the
  guest until we either re-enter the guest or decide to exit to the
  host.  This includes time spent handling hcalls in real mode.
* rm_exit - time from when we decide to exit the guest until the
  return from kvmppc_hv_entry().
* guest - time spend in the guest
* cede - time spent napping in real mode due to an H_CEDE hcall
  while other threads in the same vcore are active.

These times are exposed in debugfs in a directory per vcpu that
contains a file called "timings".  This file contains one line for
each of the 5 timings above, with the name followed by a colon and
4 numbers, which are the count (number of times the code has been
executed), the total time, the minimum time, and the maximum time,
all in nanoseconds.

The overhead of the extra code amounts to about 30ns for an hcall that
is handled in real mode (e.g. H_SET_DABR), which is about 25%.  Since
production environments may not wish to incur this overhead, the new
code is conditional on a new config symbol,
CONFIG_KVM_BOOK3S_HV_EXIT_TIMING.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2015-04-21 15:21:31 +02:00
Linus Torvalds 18a8d49973 The clock framework changes for 3.20 contain the usual driver additions,
enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
 devices. Additionaly the framework core underwent a bit of surgery with
 two major changes. The boundary between the clock core and clock
 providers (e.g clock drivers) is now more well defined with dedicated
 provider helper functions. struct clk no longer maps 1:1 with the
 hardware clock but is a true per-user cookie which helps us tracker
 users of hardware clocks and debug bad behavior. The second major change
 is the addition of rate constraints for clocks. Rate ranges are now
 supported which are analogous to the voltage ranges in the regulator
 framework. Unfortunately these changes to the core created some
 breakeage. We think we fixed it all up but for this reason there are
 lots of last minute commits trying to undo the damage.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJU54D5AAoJEDqPOy9afJhJs6AQAK5YuUwjDchdpNZx9p7OnT1q
 +poehuUwE/gYjmdACqYFyaPrI/9f43iNCfFAgKGLQqmB5ZK4sm4ktzfBEhjWINR2
 iiCx9QYMQVGiKwC8KU0ddeBciglE2b/DwxB45m9TsJEjowucUeBzwLEIj5DsGxf7
 teXRoOWgXdz1MkQJ4pnA09Q3qEPQgmu8prhMfka/v75/yn7nb9VWiJ6seR2GqTKY
 sIKL9WbKjN4AzctggdqHnMSIqZoq6vew850bv2C1fPn7GiYFQfWW+jvMlVY40dp8
 nNa2ixSQSIXVw4fCtZhTIZcIvZ8puc7WVLcl8fz3mUe3VJn1VaGs0E+Yd3GexpIV
 7bwkTOIdS8gSRlsUaIPiMnUob5TUMmMqjF4KIh/AhP4dYrmVbU7Ie8ccvSxe31Ku
 lK7ww6BFv3KweTnW/58856ZXDlXLC6x3KT+Fw58L23VhPToFgYOdTxn8AVtE/LKP
 YR3UnY9BqFx6WHXVoNvg3Piyej7RH8fYmE9om8tyWc/Ab8Eo501SHs9l3b2J8snf
 w/5STd2CYxyKf1/9JLGnBvGo754O9NvdzBttRlygB14gCCtS/SDk/ELG2Ae+/a9P
 YgRk2+257h8PMD3qlp94dLidEZN4kYxP/J6oj0t1/TIkERWfZjzkg5tKn3/hEcU9
 qM97ZBTplTm6FM+Dt/Vk
 =zCVK
 -----END PGP SIGNATURE-----

Merge tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux

Pull clock framework updates from Mike Turquette:
 "The clock framework changes contain the usual driver additions,
  enhancements and fixes mostly for ARM32, ARM64, MIPS and Power-based
  devices.

  Additionally the framework core underwent a bit of surgery with two
  major changes:

   - The boundary between the clock core and clock providers (e.g clock
     drivers) is now more well defined with dedicated provider helper
     functions.  struct clk no longer maps 1:1 with the hardware clock
     but is a true per-user cookie which helps us tracker users of
     hardware clocks and debug bad behavior.

   - The addition of rate constraints for clocks.  Rate ranges are now
     supported which are analogous to the voltage ranges in the
     regulator framework.

  Unfortunately these changes to the core created some breakeage.  We
  think we fixed it all up but for this reason there are lots of last
  minute commits trying to undo the damage"

* tag 'clk-for-linus-3.20' of git://git.linaro.org/people/mike.turquette/linux: (113 commits)
  clk: Only recalculate the rate if needed
  Revert "clk: mxs: Fix invalid 32-bit access to frac registers"
  clk: qoriq: Add support for the platform PLL
  powerpc/corenet: Enable CLK_QORIQ
  clk: Replace explicit clk assignment with __clk_hw_set_clk
  clk: Add __clk_hw_set_clk helper function
  clk: Don't dereference parent clock if is NULL
  MIPS: Alchemy: Remove bogus args from alchemy_clk_fgcs_detr
  clkdev: Always allocate a struct clk and call __clk_get() w/ CCF
  clk: shmobile: div6: Avoid division by zero in .round_rate()
  clk: mxs: Fix invalid 32-bit access to frac registers
  clk: omap: compile legacy omap3 clocks conditionally
  clkdev: Export clk_register_clkdev
  clk: Add rate constraints to clocks
  clk: remove clk-private.h
  pci: xgene: do not use clk-private.h
  arm: omap2+ remove dead clock code
  clk: Make clk API return per-user struct clk instances
  clk: tegra: Define PLLD_DSI and remove dsia(b)_mux
  clk: tegra: Add support for the Tegra132 CAR IP block
  ...
2015-02-21 12:30:30 -08:00
Cyril Bur 4be1b29795 powerpc: add running_clock for powerpc to prevent spurious softlockup warnings
On POWER8 virtualised kernels the VTB register can be read to have a view
of time that only increases while the guest is running.  This will prevent
guests from seeing time jump if a guest is paused for significant amounts
of time.

On POWER7 and below virtualised kernels stolen time is subtracted from
local_clock as a best effort approximation.  This will not eliminate
spurious warnings in the case of a suspended guest but may reduce the
occurance in the case of softlockups due to host over commit.

Bare metal kernels should avoid reading the VTB as KVM does not restore
sane values when not executing, the approxmation is fine as host kernels
won't observe any stolen time.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Jones <drjones@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: chai wen <chaiw.fnst@cn.fujitsu.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Ben Zhang <benzh@chromium.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:13 -08:00
Kevin Hao f0d3730092 powerpc: call of_clk_init() from time_init()
So the boards which has COMMON_CLK enabled don't have to
invoke this in its board specific file.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Acked-by: Michael Turquette <mturquette@linaro.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
2015-01-20 10:09:02 -08:00
Neelesh Gupta 16b1d26e77 rtc/tpo: Driver to support rtc and wakeup on PowerNV platform
The patch implements the OPAL rtc driver that binds with the rtc
driver subsystem. The driver uses the platform device infrastructure
to probe the rtc device and register it to rtc class framework. The
'wakeup' is supported depending upon the property 'has-tpo' present
in the OF node. It provides a way to load the generic rtc driver in
in the absence of an OPAL driver.

The patch also moves the existing OPAL rtc get/set time interfaces to the
new driver and exposes the necessary OPAL calls using EXPORT_SYMBOL_GPL.

Test results:
-------------
Host:
[root@tul169p1 ~]# ls -l /sys/class/rtc/
total 0
lrwxrwxrwx 1 root root 0 Oct 14 03:07 rtc0 -> ../../devices/opal-rtc/rtc/rtc0
[root@tul169p1 ~]# cat /sys/devices/opal-rtc/rtc/rtc0/time
08:10:07
[root@tul169p1 ~]# echo `date '+%s' -d '+ 2 minutes'` > /sys/class/rtc/rtc0/wakealarm
[root@tul169p1 ~]# cat /sys/class/rtc/rtc0/wakealarm
1413274345
[root@tul169p1 ~]#

FSP:
$ smgr mfgState
standby
$ rtim timeofday

System time is valid: 2014/10/14 08:12:04.225115

$ smgr mfgState
ipling
$

CC: devicetree@vger.kernel.org
CC: tglx@linutronix.de
CC: rtc-linux@googlegroups.com
CC: a.zummo@towertech.it
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-17 18:04:01 +11:00
Christoph Lameter 69111bac42 powerpc: Replace __get_cpu_var uses
This still has not been merged and now powerpc is the only arch that does
not have this change. Sorry about missing linuxppc-dev before.

V2->V2
  - Fix up to work against 3.18-rc1

__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	__this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	__this_cpu_inc(y)

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
[mpe: Fix build errors caused by set/or_softirq_pending(), and rework
      assignment in __set_breakpoint() to use memcpy().]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-03 12:12:32 +11:00
Anton Blanchard e51df2c170 powerpc: Make a bunch of things static
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-25 23:14:41 +10:00
Anton Blanchard e1802b065d powerpc: Move more symbol exports next to function definitions
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-09-25 23:14:38 +10:00
Thomas Gleixner 4a0e637738 clocksource: Get rid of cycle_last
cycle_last was added to the clocksource to support the TSC
validation. We moved that to the core code, so we can get rid of the
extra copy.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:52 -07:00
Paul Bolle 6e0fdf9af2 powerpc: fix typo 'CONFIG_PMAC'
Commit b0d278b7d3 ("powerpc/perf_event: Reduce latency of calling
perf_event_do_pending") added a check for CONFIG_PMAC were a check for
CONFIG_PPC_PMAC was clearly intended.

Fixes: b0d278b7d3 ("powerpc/perf_event: Reduce latency of calling perf_event_do_pending")
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-06-11 17:04:29 +10:00
Anton Blanchard 8050936caf powerpc: irq work racing with timer interrupt can result in timer interrupt hang
I am seeing an issue where a CPU running perf eventually hangs.
Traces show timer interrupts happening every 4 seconds even
when a userspace task is running on the CPU. /proc/timer_list
also shows pending hrtimers have not run in over an hour,
including the scheduler.

Looking closer, decrementers_next_tb is getting set to
0xffffffffffffffff, and at that point we will never take
a timer interrupt again.

In __timer_interrupt() we set decrementers_next_tb to
0xffffffffffffffff and rely on ->event_handler to update it:

        *next_tb = ~(u64)0;
        if (evt->event_handler)
                evt->event_handler(evt);

In this case ->event_handler is hrtimer_interrupt. This will eventually
call back through the clockevents code with the next event to be
programmed:

static int decrementer_set_next_event(unsigned long evt,
                                      struct clock_event_device *dev)
{
        /* Don't adjust the decrementer if some irq work is pending */
        if (test_irq_work_pending())
                return 0;
        __get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;

If irq work came in between these two points, we will return
before updating decrementers_next_tb and we never process a timer
interrupt again.

This looks to have been introduced by 0215f7d8c5 (powerpc: Fix races
with irq_work). Fix it by removing the early exit and relying on
code later on in the function to force an early decrementer:

       /* We may have raced with new irq work */
       if (test_irq_work_pending())
               set_dec(1);

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-12 14:29:28 +10:00
Preeti U Murthy 0d94873011 cpuidle/powernv: Add "Fast-Sleep" CPU idle state
Fast sleep is one of the deep idle states on Power8 in which local timers of
CPUs stop. On PowerPC we do not have an external clock device which can
handle wakeup of such CPUs. Now that we have the support in the tick broadcast
framework for archs that do not sport such a device and the low level support
for fast sleep, enable it in the cpuidle framework on PowerNV.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-05 15:57:04 +11:00
Preeti U Murthy 1b7839559b powerpc: Split timer_interrupt() into timer handling and interrupt handling routines
Split timer_interrupt(), which is the local timer interrupt handler on ppc
into routines called during regular interrupt handling and __timer_interrupt(),
which takes care of running local timers and collecting time related stats.

This will enable callers interested only in running expired local timers to
directly call into __timer_interupt(). One of the use cases of this is the
tick broadcast IPI handling in which the sleeping CPUs need to handle the local
timers that have expired.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-05 15:56:16 +11:00
Srivatsa S. Bhat 1b67bee129 powerpc: Implement tick broadcast IPI as a fixed IPI message
For scalability and performance reasons, we want the tick broadcast IPIs
to be handled as efficiently as possible. Fixed IPI messages
are one of the most efficient mechanisms available - they are faster than
the smp_call_function mechanism because the IPI handlers are fixed and hence
they don't involve costly operations such as adding IPI handlers to the target
CPU's function queue, acquiring locks for synchronization etc.

Luckily we have an unused IPI message slot, so use that to implement
tick broadcast IPIs efficiently.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[Functions renamed to tick_broadcast* and Changelog modified by
 Preeti U. Murthy<preeti@linux.vnet.ibm.com>]
Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Geoff Levand <geoff@infradead.org> [For the PS3 part]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-03-05 15:55:04 +11:00
Benjamin Herrenschmidt 0215f7d8c5 powerpc: Fix races with irq_work
If we set irq_work on a processor and immediately afterward, before the
irq work has a chance to be processed, we change the decrementer value,
we can seriously delay the handling of that irq_work.

Fix it by checking in a few places for pending irq work, first before
changing the decrementer in decrementer_set_next_event() and after
changing it in the same function and in timer_interrupt().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-01-15 13:59:03 +11:00
fan.du c041cfa2af powerpc: Make irq_stat.timers_irqs counting more specific
Current irq_stat.timers_irqs counting doesn't discriminate timer event handler
and other timer interrupt(like arch_irq_work_raise). Sometimes we need to know
exactly how much interrupts timer event handler fired, so let's be more specific
on this.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02 14:14:50 +11:00
Anton Blanchard 84b073868b powerpc/pseries: Duplicate dtl entries sometimes sent to userspace
When reading from the dispatch trace log (dtl) userspace interface, I
sometimes see duplicate entries. One example:

# hexdump -C dtl.out

00000000  07 04 00 0c 00 00 48 44  00 00 00 00 00 00 00 00
00000010  00 0c a0 b4 16 83 6d 68  00 00 00 00 00 00 00 00
00000020  00 00 00 00 10 00 13 50  80 00 00 00 00 00 d0 32

00000030  07 04 00 0c 00 00 48 44  00 00 00 00 00 00 00 00
00000040  00 0c a0 b4 16 83 6d 68  00 00 00 00 00 00 00 00
00000050  00 00 00 00 10 00 13 50  80 00 00 00 00 00 d0 32

The problem is in scan_dispatch_log() where we call dtl_consumer()
but bail out before incrementing the index.

To fix this I moved dtl_consumer() after the timebase comparison.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-11-21 10:33:39 +11:00
Linus Torvalds 39eda2aba6 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Ben Herrenschmidt:
 "Here's the powerpc batch for this merge window.  Some of the
  highlights are:

   - A bunch of endian fixes ! We don't have full LE support yet in that
     release but this contains a lot of fixes all over arch/powerpc to
     use the proper accessors, call the firmware with the right endian
     mode, etc...

   - A few updates to our "powernv" platform (non-virtualized, the one
     to run KVM on), among other, support for bridging the P8 LPC bus
     for UARTs, support and some EEH fixes.

   - Some mpc51xx clock API cleanups in preparation for a clock API
     overhaul

   - A pile of cleanups of our old math emulation code, including better
     support for using it to emulate optional FP instructions on
     embedded chips that otherwise have a HW FPU.

   - Some infrastructure in selftest, for powerpc now, but could be
     generalized, initially used by some tests for our perf instruction
     counting code.

   - A pile of fixes for hotplug on pseries (that was seriously
     bitrotting)

   - The usual slew of freescale embedded updates, new boards, 64-bit
     hiberation support, e6500 core PMU support, etc..."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits)
  powerpc: Correct FSCR bit definitions
  powerpc/xmon: Fix printing of set of CPUs in xmon
  powerpc/pseries: Move lparcfg.c to platforms/pseries
  powerpc/powernv: Return secondary CPUs to firmware on kexec
  powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32
  powerpc: Cleanup handling of the DSCR bit in the FSCR register
  powerpc/pseries: Child nodes are not detached by dlpar_detach_node
  powerpc/pseries: Add mising of_node_put in delete_dt_node
  powerpc/pseries: Make dlpar_configure_connector parent node aware
  powerpc/pseries: Do all node initialization in dlpar_parse_cc_node
  powerpc/pseries: Fix parsing of initial node path in update_dt_node
  powerpc/pseries: Pack update_props_workarea to map correctly to rtas buffer header
  powerpc/pseries: Fix over writing of rtas return code in update_dt_node
  powerpc/pseries: Fix creation of loop in device node property list
  powerpc: Skip emulating & leave interrupts off for kernel program checks
  powerpc: Add more exception trampolines for hypervisor exceptions
  powerpc: Fix location and rename exception trampolines
  powerpc: Add more trap names to xmon
  powerpc/pseries: Add a warning in the case of cross-cpu VPA registration
  powerpc: Update the 00-Index in Documentation/powerpc
  ...
2013-09-06 10:49:42 -07:00
Anton Blanchard 7ffcf8ec26 powerpc: Fix little endian lppaca, slb_shadow and dtl_entry
The lppaca, slb_shadow and dtl_entry hypervisor structures are
big endian, so we have to byte swap them in little endian builds.

LE KVM hosts will also need to be fixed but for now add an #error
to remind us.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14 15:33:35 +10:00
Anton Blanchard 6f7aba7bb4 powerpc: Add some endian annotations to time and xics code
Fix a couple of sparse warnings.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14 15:33:24 +10:00
Rusty Russell 8c6ffba0ed PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.
Sweep of the simple cases.

Cc: netdev@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-15 11:25:01 +09:30
Paul Gortmaker 061d19f279 powerpc: Delete __cpuinit usage from all users
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the powerpc uses of the __cpuinit macros.  There
are no __CPUINIT users in assembly files in powerpc.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-07-01 11:10:36 +10:00
Adrian-Leonard Radu 09652b00cd powerpc: Use PTR_RET instead of IS_ERR/PTR_ERR
Signed-off-by: Adrian-Leonard Radu <ady8radu@gmail.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
2013-04-18 13:03:48 +10:00
Linus Torvalds 266d7ad7f4 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer changes from Ingo Molnar:
 "Main changes:

   - ntp: Add CONFIG_RTC_SYSTOHC: a generic RTC driver facility
     complementing the existing CONFIG_RTC_HCTOSYS, which uses NTP to
     keep the hardware clock updated.

   - posix-timers: Fix clock_adjtime to always return timex data on
     success.  This is changing the ABI, but no breakage was expected
     and found - caution is warranted nevertheless.

   - platform persistent clock improvements/cleanups.

   - clockevents: refactor timer broadcast handling to be more generic
     and less duplicated with matching architecture code (mostly ARM
     motivated.)

   - various fixes and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet()
  posix-cpu-timers: Fix nanosleep task_struct leak
  clockevents: Fix generic broadcast for FEAT_C3STOP
  time, Fix setting of hardware clock in NTP code
  hrtimer: Prevent hrtimer_enqueue_reprogram race
  clockevents: Add generic timer broadcast function
  clockevents: Add generic timer broadcast receiver
  timekeeping: Switch HAS_PERSISTENT_CLOCK to ALWAYS_USE_PERSISTENT_CLOCK
  x86/time/rtc: Don't print extended CMOS year when reading RTC
  x86: Select HAS_PERSISTENT_CLOCK on x86
  timekeeping: Add CONFIG_HAS_PERSISTENT_CLOCK option
  rtc: Skip the suspend/resume handling if persistent clock exist
  timekeeping: Add persistent_clock_exist flag
  posix-timers: Fix clock_adjtime to always return timex data on success
  Round the calculated scale factor in set_cyc2ns_scale()
  NTP: Add a CONFIG_RTC_SYSTOHC configuration
  MAINTAINERS: Update John Stultz's email
  time: create __getnstimeofday for WARNless calls
2013-02-19 19:05:45 -08:00
Linus Torvalds d652e1eb8e Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "Main changes:

   - scheduler side full-dynticks (user-space execution is undisturbed
     and receives no timer IRQs) preparation changes that convert the
     cputime accounting code to be full-dynticks ready, from Frederic
     Weisbecker.

   - Initial sched.h split-up changes, by Clark Williams

   - select_idle_sibling() performance improvement by Mike Galbraith:

        " 1 tbench pair (worst case) in a 10 core + SMT package:

          pre   15.22 MB/sec 1 procs
          post 252.01 MB/sec 1 procs "

  - sched_rr_get_interval() ABI fix/change.  We think this detail is not
    used by apps (so it's not an ABI in practice), but lets keep it
    under observation.

  - misc RT scheduling cleanups, optimizations"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h>
  cputime: Remove irqsave from seqlock readers
  sched, powerpc: Fix sched.h split-up build failure
  cputime: Restore CPU_ACCOUNTING config defaults for PPC64
  sched/rt: Move rt specific bits into new header file
  sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice
  sched: Move sched.h sysctl bits into separate header
  sched: Fix signedness bug in yield_to()
  sched: Fix select_idle_sibling() bouncing cow syndrome
  sched/rt: Further simplify pick_rt_task()
  sched/rt: Do not account zero delta_exec in update_curr_rt()
  cputime: Safely read cputime of full dynticks CPUs
  kvm: Prepare to add generic guest entry/exit callbacks
  cputime: Use accessors to read task cputime stats
  cputime: Allow dynamic switch between tick/virtual based cputime accounting
  cputime: Generic on-demand virtual cputime accounting
  cputime: Move default nsecs_to_cputime() to jiffies based cputime file
  cputime: Librarize per nsecs resolution cputime definitions
  cputime: Avoid multiplication overflow on utime scaling
  context_tracking: Export context state for generic vtime
  ...

Fix up conflict in kernel/context_tracking.c due to comment additions.
2013-02-19 18:19:48 -08:00
Thomas Gleixner 90889a635a Merge branch 'fortglx/3.9/time' of git://git.linaro.org/people/jstultz/linux into timers/core
Trivial conflict in arch/x86/Kconfig

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-02-04 11:03:03 +01:00
Tiejun Chen 689dfa894c powerpc: Max next_tb to prevent from replaying timer interrupt
With lazy interrupt, we always call __check_irq_replaysome with
decrementers_next_tb to check if we need to replay timer interrupt.
So in hotplug case we also need to set decrementers_next_tb as MAX
to make sure __check_irq_replay don't replay timer interrupt
when return as we expect, otherwise we'll trap here infinitely.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-29 10:18:16 +11:00
Frederic Weisbecker c11f11fcbd kvm: Prepare to add generic guest entry/exit callbacks
Do some ground preparatory work before adding guest_enter()
and guest_exit() context tracking callbacks. Those will
be later used to read the guest cputime safely when we
run in full dynticks mode.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-01-27 20:35:40 +01:00
Frederic Weisbecker abf917cd91 cputime: Generic on-demand virtual cputime accounting
If we want to stop the tick further idle, we need to be
able to account the cputime without using the tick.

Virtual based cputime accounting solves that problem by
hooking into kernel/user boundaries.

However implementing CONFIG_VIRT_CPU_ACCOUNTING require
low level hooks and involves more overhead. But we already
have a generic context tracking subsystem that is required
for RCU needs by archs which plan to shut down the tick
outside idle.

This patch implements a generic virtual based cputime
accounting that relies on these generic kernel/user hooks.

There are some upsides of doing this:

- This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING
if context tracking is already built (already necessary for RCU in full
tickless mode).

- We can rely on the generic context tracking subsystem to dynamically
(de)activate the hooks, so that we can switch anytime between virtual
and tick based accounting. This way we don't have the overhead
of the virtual accounting when the tick is running periodically.

And one downside:

- There is probably more overhead than a native virtual based cputime
accounting. But this relies on hooks that are already set anyway.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-01-27 19:23:27 +01:00
Jason Gunthorpe 023f333a99 NTP: Add a CONFIG_RTC_SYSTOHC configuration
The purpose of this option is to allow ARM/etc systems that rely on the
class RTC subsystem to have the same kind of automatic NTP based
synchronization that we have on PC platforms. Today ARM does not
implement update_persistent_clock and makes extensive use of the class
RTC system.

When enabled CONFIG_RTC_SYSTOHC will provide a generic
rtc_update_persistent_clock that stores the current time in the RTC and
is intended complement the existing CONFIG_RTC_HCTOSYS option that loads
the RTC at boot.

Like with RTC_HCTOSYS the platform's update_persistent_clock is used
first, if it works. Platforms with mixed class RTC and non-RTC drivers
need to return ENODEV when class RTC should be used. Such an update for
PPC is included in this patch.

Long term, implementations of update_persistent_clock should migrate to
proper class RTC drivers and use CONFIG_RTC_SYSTOHC instead.

Tested on ARM kirkwood and PPC405

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-01-15 18:16:06 -08:00
Shan Hai ce73ec6db4 powerpc/vdso: Remove redundant locking in update_vsyscall_tz()
The locking in update_vsyscall_tz() is not only unnecessary because the vdso
code copies the data unproteced in __kernel_gettimeofday() but also
introduces a hard to reproduce race condition between update_vsyscall()
and update_vsyscall_tz(), which causes user space process to loop
forever in vdso code.

The following patch removes the locking from update_vsyscall_tz().

Locking is not only unnecessary because the vdso code copies the data
unprotected in __kernel_gettimeofday() but also erroneous because updating
the tb_update_count is not atomic and introduces a hard to reproduce race
condition between update_vsyscall() and update_vsyscall_tz(), which further
causes user space process to loop forever in vdso code.

The below scenario describes the race condition,
x==0	Boot CPU			other CPU
	proc_P: x==0
	    timer interrupt
		update_vsyscall
x==1		    x++;sync		settimeofday
					    update_vsyscall_tz
x==2						x++;sync
x==3		    sync;x++
						sync;x++
	proc_P: x==3 (loops until x becomes even)

Because the ++ operator would be implemented as three instructions and not
atomic on powerpc.

A similar change was made for x86 in commit 6c260d5863
("x86: vdso: Remove bogus locking in update_vsyscall_tz")

Signed-off-by: Shan Hai <shan.hai@windriver.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-01-03 16:45:51 +11:00
Frederic Weisbecker 1b2852b152 vtime: Warn if irqs aren't disabled on system time accounting APIs
System time accounting APIs such as vtime_account_system() and
vtime_account_idle() need to be irqsafe. Current callers include
irq entry, exit and kvm, all of which have been checked against that
requirement. Now it's better to grow that with an automatic check
in case we have further callers or we missed something.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
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>
2012-11-20 15:42:51 +01:00
Frederic Weisbecker e3942ba040 vtime: Consolidate a bit the ctx switch code
On ia64 and powerpc, vtime context switch only consists
in flushing system and user pending time, plus a few
arch housekeeping.

Consolidate that into a generic implementation. s390 is
a special case because pending user and system time accounting
there is hard to dissociate. So it's keeping its own implementation.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
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>
2012-11-19 16:41:32 +01:00
Frederic Weisbecker bcebdf8465 vtime: Explicitly account pending user time on process tick
All vtime implementations just flush the user time on process
tick. Consolidate that in generic code by calling a user time
accounting helper. This avoids an indirect call in ia64 and
prepare to also consolidate vtime context switch code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
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>
2012-11-19 16:41:21 +01:00
Frederic Weisbecker fd25b4c2f2 vtime: Remove the underscore prefix invasion
Prepending irq-unsafe vtime APIs with underscores was actually
a bad idea as the result is a big mess in the API namespace that
is even waiting to be further extended. Also these helpers
are always called from irq safe callers except kvm. Just
provide a vtime_account_system_irqsafe() for this specific
case so that we can remove the underscore prefix on other
vtime functions.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
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>
2012-11-19 16:40:16 +01:00
Frederic Weisbecker 11113334d1 vtime: Make vtime_account_system() irqsafe
vtime_account_system() currently has only one caller with
vtime_account() which is irq safe.

Now we are going to call it from other places like kvm where
irqs are not always disabled by the time we account the cputime.

So let's make it irqsafe. The arch implementation part is now
prefixed with "__".

vtime_account_idle() arch implementation is prefixed accordingly
to stay consistent.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
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>
2012-10-29 21:31:31 +01:00
Linus Torvalds 03d3602a83 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core update from Thomas Gleixner:
 - Bug fixes (one for a longstanding dead loop issue)
 - Rework of time related vsyscalls
 - Alarm timer updates
 - Jiffies updates to remove compile time dependencies

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Cast raw_interval to u64 to avoid shift overflow
  timers: Fix endless looping between cascade() and internal_add_timer()
  time/jiffies: bring back unconditional LATCH definition
  time: Convert x86_64 to using new update_vsyscall
  time: Only do nanosecond rounding on GENERIC_TIME_VSYSCALL_OLD systems
  time: Introduce new GENERIC_TIME_VSYSCALL
  time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD
  time: Move update_vsyscall definitions to timekeeper_internal.h
  time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes
  jiffies: Remove compile time assumptions about CLOCK_TICK_RATE
  jiffies: Kill unused TICK_USEC_TO_NSEC
  alarmtimer: Rename alarmtimer_remove to alarmtimer_dequeue
  alarmtimer: Remove unused helpers & defines
  alarmtimer: Use hrtimer per-alarm instead of per-base
  alarmtimer: Implement minimum alarm interval for allowing suspend
2012-10-12 22:17:48 +09:00
Linus Torvalds 5f3d2f2e1a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Benjamin Herrenschmidt:
 "Some highlights in addition to the usual batch of fixes:

   - 64TB address space support for 64-bit processes by Aneesh Kumar

   - Gavin Shan did a major cleanup & re-organization of our EEH support
     code (IBM fancy PCI error handling & recovery infrastructure) which
     paves the way for supporting different platform backends, along
     with some rework of the PCIe code for the PowerNV platform in order
     to remove home made resource allocations and instead use the
     generic code (which is possible after some small improvements to it
     done by Gavin).

   - Uprobes support by Ananth N Mavinakayanahalli

   - A pile of embedded updates from Freescale folks, including new SoC
     and board supports, more KVM stuff including preparing for 64-bit
     BookE KVM support, ePAPR 1.1 updates, etc..."

Fixup trivial conflicts in drivers/scsi/ipr.c

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits)
  powerpc/iommu: Fix multiple issues with IOMMU pools code
  powerpc: Fix VMX fix for memcpy case
  driver/mtd:IFC NAND:Initialise internal SRAM before any write
  powerpc/fsl-pci: use 'Header Type' to identify PCIE mode
  powerpc/eeh: Don't release eeh_mutex in eeh_phb_pe_get
  powerpc: Remove tlb batching hack for nighthawk
  powerpc: Set paca->data_offset = 0 for boot cpu
  powerpc/perf: Sample only if SIAR-Valid bit is set in P7+
  powerpc/fsl-pci: fix warning when CONFIG_SWIOTLB is disabled
  powerpc/mpc85xx: Update interrupt handling for IFC controller
  powerpc/85xx: Enable USB support in p1023rds_defconfig
  powerpc/smp: Do not disable IPI interrupts during suspend
  powerpc/eeh: Fix crash on converting OF node to edev
  powerpc/eeh: Lock module while handling EEH event
  powerpc/kprobe: Don't emulate store when kprobe stwu r1
  powerpc/kprobe: Complete kprobe and migrate exception frame
  powerpc/kprobe: Introduce a new thread flag
  powerpc: Remove unused __get_user64() and __put_user64()
  powerpc/eeh: Global mutex to protect PE tree
  powerpc/eeh: Remove EEH PE for normal PCI hotplug
  ...
2012-10-06 03:16:12 +09:00
Linus Torvalds 0b981cb94b Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
 "Continued quest to clean up and enhance the cputime code by Frederic
  Weisbecker, in preparation for future tickless kernel features.

  Other than that, smallish changes."

Fix up trivial conflicts due to additions next to each other in arch/{x86/}Kconfig

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  cputime: Make finegrained irqtime accounting generally available
  cputime: Gather time/stats accounting config options into a single menu
  ia64: Reuse system and user vtime accounting functions on task switch
  ia64: Consolidate user vtime accounting
  vtime: Consolidate system/idle context detection
  cputime: Use a proper subsystem naming for vtime related APIs
  sched: cpu_power: enable ARCH_POWER
  sched/nohz: Clean up select_nohz_load_balancer()
  sched: Fix load avg vs. cpu-hotplug
  sched: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW
  sched: Fix nohz_idle_balance()
  sched: Remove useless code in yield_to()
  sched: Add time unit suffix to sched sysctl knobs
  sched/debug: Limit sd->*_idx range on sysctl
  sched: Remove AFFINE_WAKEUPS feature flag
  s390: Remove leftover account_tick_vtime() header
  cputime: Consolidate vtime handling on context switch
  sched: Move cputime code to its own file
  cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING
  tile: Remove SD_PREFER_LOCAL leftover
  ...
2012-10-01 10:43:39 -07:00