The RTC controls the input source of the main 32kHz oscillator in the
system, feeding it to the clock unit too.

By default, this is using an internal, very inaccurate (+/- 30%)
oscillator with a divider to make it roughly around 32kHz. This is however
quite impractical for the RTC, since our time will not be tracked properly.

Since this oscillator is an input of the main clock unit, and since that
clock unit will be probed using CLK_OF_DECLARE, we have to use it as well,
leading to a two stage probe: one to enable the clock, the other one to
enable the RTC.

There is also a slight change in the binding that is required (and should
have been from the beginning), since we'll need a phandle to the external
oscillator used on that board. We support the old binding by not allowing
to switch to the external oscillator and only using the internal one (which
was the previous behaviour) in the case where we're missing that phandle.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The RTC is clocked from either an internal, imprecise, oscillator or an
external one, which is usually much more accurate.

The difference perceived between the time elapsed and the time reported by
the RTC is in a 10% scale, which prevents the RTC from being useful at all.

Fortunately, the external oscillator is reported to be mandatory in the
Allwinner datasheet, so we can just switch to it.

Cc: stable@vger.kernel.org
Fixes: 9765d2d9 ("rtc: sun6i: Add sun6i RTC driver")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Some registers have a read-modify-write access pattern that are not atomic.

Add some locking to prevent from concurrent accesses.

Cc: stable@vger.kernel.org
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Since we have to provide the clock very early on, the RTC driver cannot be
built as a module. Make sure that won't happen.

Cc: stable@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This adds bindings and simple probing for the Cortina Systems Gemini
SoC RTC.

Cc: Janos Laube <janos.dev@gmail.com>
Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This patches fixes comparison between signed and unsigned values as it
could produce an incorrect result when the signed value is converted to
unsigned:

drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_valid_alrm':
drivers/rtc/rtc-stm32.c:404:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if ((((tm->tm_year > cur_year) &&
...

It also fixes comparison always true or false due to the fact that unsigned
value is compared against zero with >= or <:

drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_init':
drivers/rtc/rtc-stm32.c:514:35: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
  for (pred_a = pred_a_max; pred_a >= 0; pred_a-- ) {

drivers/rtc/rtc-stm32.c:530:44: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
     (rate - ((pred_a + 1) * (pred_s + 1)) < 0) ?

Fixes: 4e64350f ("rtc: add STM32 RTC driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Using the ~ operator on a BIT() constant results in a large 'unsigned long'
constant that won't fit into an 'unsigned int' function argument on 64-bit
architectures, resulting in a harmless build warning in x86 allmodconfig:

drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_probe':
drivers/rtc/rtc-stm32.c:651:51: error: large integer implicitly truncated to unsigned type [-Werror=overflow]
  regmap_update_bits(rtc->dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP);

As PWR_CR_DBP mask prevents other bits to be cleared, replace all
~PWR_CR_DBP by 0.

Fixes: 4e64350f ("rtc: add STM32 RTC driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Accessing the registers of the RTC block on Tegra requires the module
clock to be enabled. This only works because the RTC module clock will
be enabled by default during early boot. However, because the clock is
unused, the CCF will disable it at late_init time. This causes the RTC
to become unusable afterwards. This can easily be reproduced by trying
to use the RTC:

	$ hwclock --rtc /dev/rtc1

This will hang the system. I ran into this by following up on a report
by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It
turns out that the rtc-tegra driver's ->shutdown() implementation will
hang the CPU, because of the disabled clock, before the system can be
rebooted.

What confused me for a while is that the same driver is used on prior
Tegra generations where the hang can not be observed. However, as Peter
De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC
clock is enabled by the tegra20_timer.c clocksource driver, which uses
the RTC to provide a persistent clock. This code is never enabled on
64-bit Tegra because the persistent clock infrastructure does not exist
on 64-bit ARM.

The proper fix for this is to add proper clock handling to the RTC
driver in order to ensure that the clock is enabled when the driver
requires it. All device trees contain the clock already, therefore
no additional changes are required.
Reported-by: Martin Michlmayr <tbm@cyrius.com>
Acked-By Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The ordering of includes is currently completely arbitrary, making it
impossible to decide where to put new includes. Remove the dilemma by
sort the include list alphabetically.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The new driver has a stray #ifdef in it that causes a build error:

drivers/rtc/rtc-stm32.c:718:21: error: 'stm32_rtc_of_match' undeclared here (not in a function); did you mean 'stm32_rtc_pm_ops'?

As the #ifdef serves no purpose here, let's just remove it.

Fixes: 4e64350f ("rtc: add STM32 RTC driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The remove function can be called at runtime for a manual 'unbind'
operation and must not be left out from a built-in driver, as kbuild
complains:

`stm32_rtc_remove' referenced in section `.data.stm32_rtc_driver' of drivers/rtc/rtc-stm32.o: defined in discarded section `.exit.text' of drivers/rtc/rtc-stm32.o

This removes the extraneous annotation.

Fixes: 4e64350f ("rtc: add STM32 RTC driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This patch adds support for the STM32 RTC.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This patch adds documentation of device tree bindings for the STM32 RTC.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Armada38x wants to modify its rtc_class_ops to remove the interrupt
handling when there is no usable interrupt, but this means we leave
function pointers in writable memory.

Since rtc_class_ops is small, arrange to have two instances, one for
when we have interrupts, and one for when we have none, both marked
const.  This allows the compiler to place them in read-only memory,
which is better than placing them in __ro_after_init.

Thanks to Bhumika Goyal <bhumirks@gmail.com> for pointing out that
the structure was writable and submitting a patch to add
__ro_after_init.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Declare rtc_class_ops structures as const as they are only passed
as an argument to the function devm_rtc_device_register. This argument
is of type const struct rtc_class_ops *, so rtc_class_ops structures
having this property can be declared const.
Done using Coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct rtc_class_ops i@p = {...};

@ok1@
identifier r1.i;
position p;
@@
devm_rtc_device_register(...,&i@p,...)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct rtc_class_ops i;
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Document the DryIce security violation interrupt.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The DryIce chipset has a dedicated security violation interrupt that is
triggered for security violations (if configured to do so).  According
to the publicly available imx258 reference manual, irq 56 is used for
this interrupt.

If an irq number is provided for the security violation interrupt,
install the same handler that we're already using for the "normal"
interrupt.

imxdi->irq is used only in the probe function, make it a local variable.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This patch adds alarm support. This allows to configure the chip
to generate an interrupt when the alarm matches current time value.
Alarm can be programmed up to one year in the future
and is accurate to the second.
Signed-off-by: Emil Bartczak <emilbart@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This patch adds support for saving/loading weekday value from the chip.
Signed-off-by: Emil Bartczak <emilbart@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

According to RES-3124064:

The device supports CPU write and read access to the RTC time register.
However, due to this restriction, read and write from/to internal RTC
register may fail.

Workaround:
General setup:
1. Configure the RTC Mbus Bridge Timing Control register (offset 0x184A0)
   to value 0xFD4D4FFF
   Write RTC WRCLK Period to its maximum value (0x3FF)
   Write RTC WRCLK setup to 0x29
   Write RTC WRCLK High Time to 0x53 (default value)
   Write RTC Read Output Delay to its maximum value (0x1F)
   Mbus - Read All Byte Enable to 0x1 (default value)
2. Configure the RTC Test Configuration Register (offset 0xA381C) bit3
   to '1' (Reserved, Marvell internal)

For any RTC register read operation:
1. Read the requested register 100 times.
2. Find the result that appears most frequently and use this result
   as the correct value.

For any RTC register write operation:
1. Issue two dummy writes of 0x0 to the RTC Status register (offset
   0xA3800).
2. Write the time to the RTC Time register (offset 0xA380C).

This patch is based on the work of Shaker Daibes
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Fixes checkpatch.pl warning:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Texas Instrument's TPS65910 has support for compensating RTC crystal
inaccuracies. When enabled every hour RTC counter value will be compensated
with two's complement value.
Signed-off-by: Vesa Jääskeläinen <vesa.jaaskelainen@vaisala.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Remove spinlock and use the "rtc->ops_lock" from RTC subsystem instead.
spin_lock_irqsave() is not needed here because we do not have hard IRQs.

This patch fixes the following issue:

root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
root@GE004097290448 b850v3:~# hwclock --systohc
[   82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855
[   82.113660]  lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1
[   82.121329] CPU: 0 PID: 855 Comm: hwclock Not tainted 4.8.0-00042-g09d5410-dirty #20
[   82.129078] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[   82.135609] Backtrace:
[   82.138090] [<8010d378>] (dump_backtrace) from [<8010d5c0>] (show_stack+0x20/0x24)
[   82.145664]  r7:ec936000 r6:600a0013 r5:00000000 r4:81031680
[   82.151402] [<8010d5a0>] (show_stack) from [<80401518>] (dump_stack+0xb4/0xe8)
[   82.158636] [<80401464>] (dump_stack) from [<8017b8b0>] (spin_dump+0x84/0xcc)
[   82.165775]  r10:00000000 r9:ec936000 r8:81056090 r7:600a0013 r6:edb4899c r5:edb4899c
[   82.173691]  r4:e5033e00 r3:00000000
[   82.177308] [<8017b82c>] (spin_dump) from [<8017bcb0>] (do_raw_spin_unlock+0x108/0x130)
[   82.185314]  r5:edb4899c r4:edb4899c
[   82.188938] [<8017bba8>] (do_raw_spin_unlock) from [<8094b93c>] (_raw_spin_unlock_irqrestore+0x34/0x54)
[   82.198333]  r5:edb4899c r4:600a0013
[   82.201953] [<8094b908>] (_raw_spin_unlock_irqrestore) from [<8065b090>] (rx8010_set_time+0x14c/0x188)
[   82.211261]  r5:00000020 r4:edb48990
[   82.214882] [<8065af44>] (rx8010_set_time) from [<80653fe4>] (rtc_set_time+0x70/0x104)
[   82.222801]  r7:00000051 r6:edb39da0 r5:edb39c00 r4:ec937e8c
[   82.228535] [<80653f74>] (rtc_set_time) from [<80655774>] (rtc_dev_ioctl+0x3c4/0x674)
[   82.236368]  r7:00000051 r6:7ecf1b74 r5:00000000 r4:edb39c00
[   82.242106] [<806553b0>] (rtc_dev_ioctl) from [<80284034>] (do_vfs_ioctl+0xa4/0xa6c)
[   82.249851]  r8:00000003 r7:80284a40 r6:ed1e9c80 r5:edb44e60 r4:7ecf1b74
[   82.256642] [<80283f90>] (do_vfs_ioctl) from [<80284a40>] (SyS_ioctl+0x44/0x6c)
[   82.263953]  r10:00000000 r9:ec936000 r8:7ecf1b74 r7:4024700a r6:ed1e9c80 r5:00000003
[   82.271869]  r4:ed1e9c80
[   82.274432] [<802849fc>] (SyS_ioctl) from [<80108520>] (ret_fast_syscall+0x0/0x1c)
[   82.282005]  r9:ec936000 r8:801086c4 r7:00000036 r6:00000000 r5:00000003 r4:0008e1bc
root@GE004097290448 b850v3:~#
Message from syslogd@GE004097290448 at Dec  3 11:17:08 ...
 kernel:[   82.108175] BUG: spinlock wrong CPU on CPU#0, hwclock/855

Message from syslogd@GE004097290448 at Dec  3 11:17:08 ...
 kernel:[   82.113660]  lock: 0xedb4899c, .magic: dead4ead, .owner: hwclock/855, .owner_cpu: 1
hwclock --systohc
root@GE004097290448 b850v3:~#
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

I am getting the following warning when I build kernel 4.9-git on my
PowerBook G4 with a 32-bit PPC processor:

    AS      arch/powerpc/kernel/misc_32.o
  arch/powerpc/kernel/misc_32.S:299:7: warning: "CONFIG_FSL_BOOKE" is not defined [-Wundef]

This problem is evident after commit 989cea5c ("kbuild: prevent
lib-ksyms.o rebuilds"); however, this change in kbuild only exposes an
error that has been in the code since 2005 when this source file was
created.  That was with commit 9994a338 ("powerpc: Introduce
entry_{32,64}.S, misc_{32,64}.S, systbl.S").

The offending line does not make a lot of sense.  This error does not
seem to cause any errors in the executable, thus I am not recommending
that it be applied to any stable versions.

Thanks to Nicholas Piggin for suggesting this solution.

Fixes: 9994a338 ("powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Nicholas Piggin <npiggin@gmail.com>
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: Linus Torvalds <torvalds@linux-foundation.org>

The timer type simplifications caused a new gcc warning:

  drivers/base/power/domain.c: In function ‘genpd_runtime_suspend’:
  drivers/base/power/domain.c:562:14: warning: ‘time_start’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));

despite the actual use of "time_start" not having changed in any way.
It appears that simply changing the type of ktime_t from a union to a
plain scalar type made gcc check the use.

The variable wasn't actually used uninitialized, but gcc apparently
failed to notice that the conditional around the use was exactly the
same as the conditional around the initialization of that variable.

Add an unnecessary initialization just to shut up the compiler.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t

Pull SMP hotplug notifier removal from Thomas Gleixner:
 "This is the final cleanup of the hotplug notifier infrastructure. The
  series has been reintgrated in the last two days because there came a
  new driver using the old infrastructure via the SCSI tree.

  Summary:

   - convert the last leftover drivers utilizing notifiers

   - fixup for a completely broken hotplug user

   - prevent setup of already used states

   - removal of the notifiers

   - treewide cleanup of hotplug state names

   - consolidation of state space

  There is a sphinx based documentation pending, but that needs review
  from the documentation folks"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/armada-xp: Consolidate hotplug state space
  irqchip/gic: Consolidate hotplug state space
  coresight/etm3/4x: Consolidate hotplug state space
  cpu/hotplug: Cleanup state names
  cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions
  staging/lustre/libcfs: Convert to hotplug state machine
  scsi/bnx2i: Convert to hotplug state machine
  scsi/bnx2fc: Convert to hotplug state machine
  cpu/hotplug: Prevent overwriting of callbacks
  x86/msr: Remove bogus cleanup from the error path
  bus: arm-ccn: Prevent hotplug callback leak
  perf/x86/intel/cstate: Prevent hotplug callback leak
  ARM/imx/mmcd: Fix broken cpu hotplug handling
  scsi: qedi: Convert to hotplug state machine

Pull turbostat updates from Len Brown.

* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools/power turbostat: remove obsolete -M, -m, -C, -c options
  tools/power turbostat: Make extensible via the --add parameter
  tools/power turbostat: Denverton uses a 25 MHz crystal, not 19.2 MHz
  tools/power turbostat: line up headers when -M is used
  tools/power turbostat: fix SKX PKG_CSTATE_LIMIT decoding
  tools/power turbostat: Support Knights Mill (KNM)
  tools/power turbostat: Display HWP OOB status
  tools/power turbostat: fix Denverton BCLK
  tools/power turbostat: use intel-family.h model strings
  tools/power/turbostat: Add Denverton RAPL support
  tools/power/turbostat: Add Denverton support
  tools/power/turbostat: split core MSR support into status + limit
  tools/power turbostat: fix error case overflow read of slm_freq_table[]
  tools/power turbostat: Allocate correct amount of fd and irq entries
  tools/power turbostat: switch to tab delimited output
  tools/power turbostat: Gracefully handle ACPI S3
  tools/power turbostat: tidy up output on Joule counter overflow

Add a new page flag, PageWaiters, to indicate the page waitqueue has
tasks waiting. This can be tested rather than testing waitqueue_active
which requires another cacheline load.

This bit is always set when the page has tasks on page_waitqueue(page),
and is set and cleared under the waitqueue lock. It may be set when
there are no tasks on the waitqueue, which will cause a harmless extra
wakeup check that will clears the bit.

The generic bit-waitqueue infrastructure is no longer used for pages.
Instead, waitqueues are used directly with a custom key type. The
generic code was not flexible enough to have PageWaiters manipulation
under the waitqueue lock (which simplifies concurrency).

This improves the performance of page lock intensive microbenchmarks by
2-3%.

Putting two bits in the same word opens the opportunity to remove the
memory barrier between clearing the lock bit and testing the waiters
bit, after some work on the arch primitives (e.g., ensuring memory
operand widths match and cover both bits).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A page is not added to the swap cache without being swap backed,
so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

No point in going through loops and hoops instead of just comparing the
values.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

ktime is a union because the initial implementation stored the time in
scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
variant for 32bit machines. The Y2038 cleanup removed the timespec variant
and switched everything to scalar nanoseconds. The union remained, but
become completely pointless.

Get rid of the union and just keep ktime_t as simple typedef of type s64.

The conversion was done with coccinelle and some manual mopping up.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>

The mpic is either the main interrupt controller or is cascaded behind a
GIC. The mpic is single instance and the modes are mutually exclusive, so
there is no reason to have seperate cpu hotplug states.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/20161221192112.333161745@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

Even if both drivers are compiled in only one instance can run on a given
system depending on the available GIC version.

So having seperate hotplug states for them is pointless.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.252416267@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

Even if both drivers are compiled in only one instance can run on a given
system depending on the available tracer cell.

So having seperate hotplug states for them is pointless.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: http://lkml.kernel.org/r/20161221192112.162765484@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

hotcpu_notifier(), cpu_notifier(), __hotcpu_notifier(), __cpu_notifier(),
register_hotcpu_notifier(), register_cpu_notifier(),
__register_hotcpu_notifier(), __register_cpu_notifier(),
unregister_hotcpu_notifier(), unregister_cpu_notifier(),
__unregister_hotcpu_notifier(), __unregister_cpu_notifier()

are unused now. Remove them and all related code.

Remove also the now pointless cpu notifier error injection mechanism. The
states can be executed step by step and error rollback is the same as cpu
down, so any state transition can be tested w/o requiring the notifier
error injection.

Some CPU hotplug states are kept as they are (ab)used for hotplug state
tracking.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161221192112.005642358@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>