watchdog: Add a flag to indicate the watchdog doesn't reboot things

Some watchdogs merely trigger external alarms and controls. In a managed
environment this is very useful but we want drivers to be able to figure
out which is which now multiple dogs can be loaded. Thus add an ALARMONLY
feature flag.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: create all the proper device files

Create the watchdog class and it's associated devices.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: use dev_ functions

While they are registered all our watchdogs now have a valid device object
so we can in turn use that to report problems nicely.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: watchdog_dev: Rewrite wrapper code

Rewrite and extend the wrapper code so that we can easily introduce
locking (this to be able to prevent potential multithreading issues).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: Add Locking support

This patch fixes some potential multithreading issues, despite only
allowing one process to open the /dev/watchdog device, we can still get
called multiple times at the same time, since a program could be using thread,
or could share the fd after a fork.

This causes 2 potential problems:
1) watchdog_start / open do an unlocked test_n_set / test_n_clear,
   if these 2 race, the watchdog could be stopped while the active
   bit indicates it is running or visa versa.

2) Most watchdog_dev drivers probably assume that only one
   watchdog-op will get called at a time, this is not necessary
   true atm.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: Add support for dynamically allocated watchdog_device structs

If a driver's watchdog_device struct is part of a dynamically allocated
struct (which it often will be), merely locking the module is not enough,
even with a drivers module locked, the driver can be unbound from the device,
examples:
1) The root user can unbind it through sysfd
2) The i2c bus master driver being unloaded for an i2c watchdog

I will gladly admit that these are corner cases, but we still need to handle
them correctly.

The fix for this consists of 2 parts:
1) Add ref / unref operations, so that the driver can refcount the struct
   holding the watchdog_device struct and delay freeing it until any
   open filehandles referring to it are closed
2) Most driver operations will do IO on the device and the driver should not
   do any IO on the device after it has been unbound. Rather then letting each
   driver deal with this internally, it is better to ensure at the watchdog
   core level that no operations (other then unref) will get called after
   the driver has called watchdog_unregister_device(). This actually is the
   bulk of this patch.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: sch56xx: Use watchdog core

Convert sch56xx drivers to the generic watchdog core.

Note this patch depends on the "watchdog: Add multiple device support" patch
from Alan Cox.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: sch56xx: Remove unnecessary checks for register changes

Since the watchdog core keeps track of the watchdog's active state, start/stop
will never get called when no changes are necessary. So we can remove the
check for the output_enable register changing before writing it (which is
an expensive operation).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: sch56xx-common: Add proper ref-counting of watchdog data

This fixes referencing free-ed memory in the corner case where /dev/watchdog
is open when the platform driver gets unbound from the platform device.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Watchdog: DA9052/53 PMIC watchdog support

This driver adds support for the watchdog functionality provided by
the Dialog Semiconductor DA9052 PMIC chip.

Tested on samsung smdkv6410 and i.mx53 QS boards.

Signed-off-by: Anthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: sch56xx-common: set correct bits in register()

WDOG_NO_WAY_OUT (3) and WDOG_ACTIVE (0) are the bit numbers, not a mask.
So "data->wddev.status |= WDOG_ACTIVE;" was intended to set bit zero but
it is a no-op.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
hwmon/sch56xx: Depend on watchdog for watchdog core functions

Since the watchdog code in sch56xx-common now uses the watchdog core, the
Kconfig entires for the sch5627 and sch5636 should depend on WATCHDOG
being set. Also select the watchdog core when we select one of the drivers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: sp805_wdt: convert to watchdog core

This patch converts existing sp805 watchdog driver to use already in place
common infrastructure present in watchdog core. With this lot of code goes away.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: sp805_wdt: Add clk_{un}prepare support

clk_{un}prepare() routines are required for required on some platforms to run
part of clk enable/disable() routines from contexts that can schedule.

This patch adds support for these routines in sp805 driver.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
watchdog: iTCO_wdt.c: fix printk format warnings

Fix printk format warnings:

drivers/watchdog/iTCO_wdt.c:577:3: warning: format '%04llx' expects type 'long long unsigned int', but argument 2 has type 'resource_size_t'
drivers/watchdog/iTCO_wdt.c:594:3: warning: format '%04llx' expects type 'long long unsigned int', but argument 2 has type 'resource_size_t'
drivers/watchdog/iTCO_wdt.c:600:2: warning: format '%04llx' expects type 'long long unsigned int', but argument 4 has type 'resource_size_t'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Fixes for perf/urgent from Arnaldo Carvalho de Melo:

 * Fix fallback to --stdio when TUI not supported, from Namhyung Kim.

 * Use right cast for pointers/long in libtraceevent, from Namhyung Kim.

 * Be consistent on using the right error reporting interface for fatal errors,
   from Namhyung Kim.

 * Fix fallback to --stdio when TUI not supported, from Namhyung Kim.

 * Use the right index in asm only view in the annotate browser.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Annotation fixes/improvements from Arnaldo Carvalho de Melo:

. Make the annotatation toggles (hide_src_code, jump_arrows, use_offset, etc)
  global so that navigation doesn't resets them on new annotations.

. Introduce an '[annotate]' config file section to allow permanent changes
  to the annotate browser defaults.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
s390/kernel: Introduce memcpy_absolute() function

This patch introduces the new function memcpy_absolute() that allows to
copy memory using absolute addressing. This means that the prefix swap
does not apply when this function is used.

With this patch also all s390 kernel code that accesses absolute zero
now uses the new memcpy_absolute() function. The old and less generic
copy_to_absolute_zero() function is removed.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/kernel: Fix smp_call_ipl_cpu() for offline CPUs

If the IPL CPU is offline, currently the pcpu_delegate() function
used by smp_call_ipl_cpu() does not work because pcpu_delegate()
modifies the lowcore of the target CPU. In case of an offline
IPL CPU currently the prefix register is zero but pcpu->lowcore
still points to the old prefix page. Therefore the lowcore changes
done by pcpu_delegate() have no effect.

With this fix pcpu_delegate() now uses memcpy_absolute() and therefore
also prepares the absolute zero lowcore if the target CPU has prefix
register zero.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/cpu: remove cpu "capabilities" sysfs attribute

It has been a big mistage to add the capabilities attribute to the
cpus in sysfs:
First the attribute only contains the cpu capability of primary cpus,
which however is not necessarily (or better: unlikely) the type of
cpu the kernel runs on, which is typically an IFL.
In addition all information that is necessary is available in
/proc/sysinfo already. So this attribute partially duplicated
informations.
So programs should look into the sysinfo file to retrieve all
informations they are interested in.

Since with this kernel release also the powersavings cpu attributes
are removed this seems to be a good opportunity to remove another
broken interface.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>