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path: root/drivers/rtc/rtc-opal.c
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2018-05-01rtc: opal: Fix OPAL RTC driver OPAL_BUSY loopsNicholas Piggin
commit 682e6b4da5cbe8e9a53f979a58c2a9d7dc997175 upstream. The OPAL RTC driver does not sleep in case it gets OPAL_BUSY or OPAL_BUSY_EVENT from firmware, which causes large scheduling latencies, up to 50 seconds have been observed here when RTC stops responding (BMC reboot can do it). Fix this by converting it to the standard form OPAL_BUSY loop that sleeps. Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks") Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22rtc-opal: Fix handling of firmware error codes, prevent busy loopsStewart Smith
commit 5b8b58063029f02da573120ef4dc9079822e3cda upstream. According to the OPAL docs: skiboot-5.2.5/doc/opal-api/opal-rtc-read-3.txt skiboot-5.2.5/doc/opal-api/opal-rtc-write-4.txt OPAL_HARDWARE may be returned from OPAL_RTC_READ or OPAL_RTC_WRITE and this indicates either a transient or permanent error. Prior to this patch, Linux was not dealing with OPAL_HARDWARE being a permanent error particularly well, in that you could end up in a busy loop. This was not too hard to trigger on an AMI BMC based OpenPOWER machine doing a continuous "ipmitool mc reset cold" to the BMC, the result of that being that we'd get stuck in an infinite loop in opal_get_rtc_time(). We now retry a few times before returning the error higher up the stack. Fixes: 16b1d26e77b1 ("rtc/tpo: Driver to support rtc and wakeup on PowerNV platform") Cc: stable@vger.kernel.org # v3.19+ Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24rtc: opal: Implement rtc_class_ops.alarm_irq_enable callbackVaibhav Jain
Provide an implementation of the callback rtc_class_ops.alarm_irq_enable for rtc-opal driver. This callback is called when the wake alarm is disabled via the command: 'echo 0 > /sys/class/rtc/rtc0/wakealarm' Without this the Timed-Power-On(TPO) config remains set even when its disabled by the above command and FSP will still force machine boot at previously configured alarm time. The callback is implemented as function opal_tpo_alarm_irq_enable() which calls opal_set_tpo_time() with alarm.enabled == 0. A branch is added to opal_set_tpo_time() to handle this case by passing y_m_d == h_m_s_ms == 0 to opal as arguments for opal_tpo_write() call. Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-05-31rtc: opal: Handle disabled TPO in opal_get_tpo_time()Vaibhav Jain
On PowerNV platform when Timed-Power-On(TPO) is disabled, read of stored TPO yields value with all date components set to '0' inside opal_get_tpo_time(). The function opal_to_tm() then converts it to an offset from year 1900 yielding alarm-time == "1900-00-01 00:00:00". This causes problems with __rtc_read_alarm() that expecting an offset from "1970-00-01 00:00:00" and returned alarm-time results in a -ve value for time64_t. Which ultimately results in this error reported in kernel logs with a seemingly garbage value: "rtc rtc0: invalid alarm value: -2-1--1041528741 2005511117:71582844:32" We fix this by explicitly handling the case of all alarm date-time components being '0' inside opal_get_tpo_time() and returning -ENOENT in such a case. This signals generic rtc that no alarm is set and it bails out from the alarm initialization flow without reporting the above error. Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Reported-by: Steve Best <sbest@redhat.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-06-29powerpc/opal: Add inline function to get rc from an ASYNC_COMP opal_msgSuraj Jitindar Singh
An opal_msg of type OPAL_MSG_ASYNC_COMP contains the return code in the params[1] struct member. However this isn't intuitive or obvious when reading the code and requires that a user look at the skiboot documentation or opal-api.h to verify this. Add an inline function to get the return code from an opal_msg and update call sites accordingly. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-16powerpc: Remove broken GregorianDay()Daniel Axtens
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>
2015-11-08rtc: opal: enable support for the stardard "wakeup-source" propertySudeep Holla
Though the opal rtc driver should and will continue to support the legacy "has-tpo" property to enable RTC as the wakeup source, we need to add support for the new standard property "wakeup-source" This patch adds support for "wakeup-source" property in addition to the existing "has-tpo" property. Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: rtc-linux@googlegroups.com Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-11-08rtc: opal: fix type of tokenAndrzej Hajda
The variable can take signed values. The problem has been detected using proposed semantic patch scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1]. [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576 Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05rtc: opal: Enable alarms only when opal supports tpoVaibhav Jain
rtc-opal driver provides support for rtc alarms via timed-power-on(tpo). However some Power platforms like BML use a fake rtc clock and don't support tpo. Such platforms are indicated by the missing 'has-tpo' property in the device tree. Current implementation however enables callback for rtc_class_ops.read/set alarm irrespective of the tpo support from the platform. This results in a failed opal call when kernel tries to read an existing alarms via opal_get_tpo_time during rtc device registration. This patch fixes this issue by setting opal_rtc_ops.read/set_alarm callback pointers only when tpo is supported. Acked-by: Michael Neuling <mikey@neuling.org> Acked-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05rtc: Drop owner assignment from platform_driverKrzysztof Kozlowski
platform_driver does not need to set an owner because platform_driver_register() will set it. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-04-17rtc: use more standard kernel logging stylesJoe Perches
Neaten the logging a bit by adding #define pr_fmt Miscellanea: o Remove __FILE__/__func__ uses o Coalesce formats adding missing spaces o Align arguments o (rtc-cmos) Integrated 2 consecutive messages Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-17rtc/tpo: Driver to support rtc and wakeup on PowerNV platformNeelesh Gupta
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>