[Skiboot] [PATCH 3/3] ipmi/wdt: Add ipmi watchdog timer support
Alistair Popple
alistair at popple.id.au
Tue Jan 13 15:21:15 AEDT 2015
Add support for an ipmi watchdog timer. This patch will cause the
system to be reset if opal_run_pollers() isn't called for more than
about 60 seconds.
The timer is reset just prior to running the payload. It is the
responsibility of the payload to ensure either opal_run_pollers() is
called frequently enough or to disable the watchdog timer by sending
appropriate ipmi commands.
Signed-off-by: Alistair Popple <alistair at popple.id.au>
---
core/init.c | 7 ++-
hw/ipmi/Makefile.inc | 1 +
hw/ipmi/ipmi-watchdog.c | 142 ++++++++++++++++++++++++++++++++++++++++++++
include/ipmi.h | 13 ++++
platforms/astbmc/common.c | 1 +
platforms/astbmc/palmetto.c | 1 +
6 files changed, 163 insertions(+), 2 deletions(-)
create mode 100644 hw/ipmi/ipmi-watchdog.c
diff --git a/core/init.c b/core/init.c
index cffa638..ffd4621 100644
--- a/core/init.c
+++ b/core/init.c
@@ -44,6 +44,8 @@
#include <hostservices.h>
#include <timer.h>
+#include <ipmi.h>
+
/*
* Boot semaphore, incremented by each CPU calling in
*
@@ -367,7 +369,7 @@ void __noreturn load_and_boot_kernel(bool is_reboot)
}
fsp_console_select_stdout();
- /*
+ /*
* OCC takes few secs to boot. Call this as late as
* as possible to avoid delay.
*/
@@ -672,6 +674,8 @@ void __noreturn main_cpu_entry(const void *fdt, u32 master_cpu)
/* ... and add remaining reservations to the DT */
mem_region_add_dt_reserved();
+ ipmi_wdt_reset();
+
load_and_boot_kernel(false);
}
@@ -707,4 +711,3 @@ void __noreturn secondary_cpu_entry(void)
__secondary_cpu_entry();
}
-
diff --git a/hw/ipmi/Makefile.inc b/hw/ipmi/Makefile.inc
index 02670d7..1c358a9 100644
--- a/hw/ipmi/Makefile.inc
+++ b/hw/ipmi/Makefile.inc
@@ -1,5 +1,6 @@
SUBDIRS += hw/ipmi
IPMI_OBJS = ipmi-rtc.o ipmi-power.o ipmi-opal.o ipmi-fru.o ipmi-sel.o
+IPMI_OBJS += ipmi-watchdog.o
IPMI = hw/ipmi/built-in.o
$(IPMI): $(IPMI_OBJS:%=hw/ipmi/%)
diff --git a/hw/ipmi/ipmi-watchdog.c b/hw/ipmi/ipmi-watchdog.c
new file mode 100644
index 0000000..20607ec
--- /dev/null
+++ b/hw/ipmi/ipmi-watchdog.c
@@ -0,0 +1,142 @@
+
+/* Copyright 2013-2014 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <ipmi.h>
+#include <lock.h>
+#include <opal.h>
+#include <device.h>
+#include <timer.h>
+#include <timebase.h>
+
+#define TIMER_USE_DONT_LOG 0x80
+#define TIMER_USE_DONT_STOP 0x40
+#define TIMER_USE_POST 0x02
+
+/* WDT expiration actions */
+#define WDT_POWER_CYCLE_ACTION 0x01
+#define WDT_NO_ACTION 0x00
+
+/* How long to set the overall watchdog timeout for. In units of
+ * 100ms. If the timer is not reset within this time the watchdog
+ * expiration action will occur. */
+#define WDT_TIMEOUT 600
+
+/* How often to reset the timer using schedule_timer(). Too short and
+we risk accidently resetting the system due to opal_run_pollers() not
+being called in time, too short and we waste time resetting the wdt
+more frequently than neccessary. */
+#define WDT_MARGIN 300
+
+static struct lock ipmi_msg_lock = LOCK_UNLOCKED;
+static bool ipmi_msg_busy = true;
+static struct ipmi_msg *ipmi_msg;
+static struct timer wdt_timer;
+
+static void ipmi_wdt_complete(struct ipmi_msg *msg)
+{
+ ipmi_msg_busy = false;
+
+ if (msg->cmd == IPMI_CMD(IPMI_RESET_WDT) && !msg->user_data)
+ schedule_timer(&wdt_timer, msecs_to_tb((WDT_TIMEOUT - WDT_MARGIN)*100));
+}
+
+/* As the WDT message is used continually we reduce stress on the
+ * memory allocator by using a single message. This function waits for
+ * the message to become available by running the pollers to flush the
+ * queue. For the WDT case this makes sense as a backlog of IPMI
+ * messages could cause a reset if we don't prioritise the processing
+ * of the IPMI message queue. */
+static void get_ipmi_msg(void)
+{
+retry:
+ while (ipmi_msg_busy)
+ time_wait_ms(100);
+
+ lock(&ipmi_msg_lock);
+ if (ipmi_msg_busy) {
+ unlock(&ipmi_msg_lock);
+ goto retry;
+ }
+
+ ipmi_msg_busy = true;
+ unlock(&ipmi_msg_lock);
+}
+
+static void set_wdt(uint8_t action, uint16_t count)
+{
+ get_ipmi_msg();
+ ipmi_init_msg(ipmi_msg, IPMI_DEFAULT_INTERFACE, IPMI_SET_WDT,
+ ipmi_wdt_complete, NULL, 6, 0);
+ ipmi_msg->data[0] = TIMER_USE_DONT_LOG
+ | TIMER_USE_POST; /* Timer Use */
+ ipmi_msg->data[1] = action; /* Timer Actions */
+ ipmi_msg->data[2] = 0; /* Pre-timeout Interval */
+ ipmi_msg->data[3] = 0; /* Timer Use Flags */
+ ipmi_msg->data[4] = count & 0xff; /* Initial countdown (lsb) */
+ ipmi_msg->data[5] = (count >> 8) & 0xff; /* Initial countdown (msb) */
+ ipmi_queue_msg(ipmi_msg);
+}
+
+static void reset_wdt(struct timer *t __unused, void *data)
+{
+ get_ipmi_msg();
+ ipmi_init_msg(ipmi_msg, IPMI_DEFAULT_INTERFACE, IPMI_RESET_WDT,
+ ipmi_wdt_complete, data, 0, 0);
+ ipmi_queue_msg(ipmi_msg);
+}
+
+void ipmi_wdt_final_reset(void)
+{
+ cancel_timer(&wdt_timer);
+ reset_wdt(NULL, (void *) !NULL);
+}
+
+void ipmi_wdt_reset(void)
+{
+ cancel_timer(&wdt_timer);
+ reset_wdt(NULL, NULL);
+}
+
+void ipmi_wdt_init(void)
+{
+ ipmi_msg = ipmi_mkmsg(IPMI_DEFAULT_INTERFACE, IPMI_SET_WDT,
+ ipmi_wdt_complete, NULL, NULL, 6, 0);
+ if (!ipmi_msg) {
+ prerror("Unable to allocate watchdog ipmi message\n");
+ return;
+ }
+
+ ipmi_msg_busy = false;
+ init_timer(&wdt_timer, reset_wdt, NULL);
+ set_wdt(WDT_POWER_CYCLE_ACTION, WDT_TIMEOUT);
+
+ /* Start the WDT */
+ reset_wdt(NULL, NULL);
+
+ /* For some reason we have to reset it twice to get it to
+ * actually start the first time. */
+ reset_wdt(NULL, NULL);
+
+ /* Crank the state machines until we've processed the reset
+ * command to start the wdt. This ensures the wdt has started
+ * before we hand control over to the rest of the system.*/
+ get_ipmi_msg();
+ ipmi_msg_busy = false;
+
+ return;
+}
diff --git a/include/ipmi.h b/include/ipmi.h
index bbeae5a..40dee24 100644
--- a/include/ipmi.h
+++ b/include/ipmi.h
@@ -93,6 +93,8 @@
#define IPMI_CHASSIS_CONTROL IPMI_CODE(IPMI_NETFN_CHASSIS, 0x02)
#define IPMI_SET_POWER_STATE IPMI_CODE(IPMI_NETFN_APP, 0x06)
#define IPMI_GET_POWER_STATE IPMI_CODE(IPMI_NETFN_APP, 0x07)
+#define IPMI_RESET_WDT IPMI_CODE(IPMI_NETFN_APP, 0x22)
+#define IPMI_SET_WDT IPMI_CODE(IPMI_NETFN_APP, 0x24)
#define IPMI_PARTIAL_ADD_ESEL IPMI_CODE(IPMI_NETFN_OEM, 0xf0)
@@ -202,4 +204,15 @@ void ipmi_fru_init(uint8_t fru_dev_id);
struct errorlog;
int ipmi_elog_commit(struct errorlog *elog_buf);
+/* Starts the watchdog timer */
+void ipmi_wdt_init(void);
+
+/* Queue a watchdog timer reset. Schedules future resets to prevent
+ * timer expiration. */
+void ipmi_wdt_reset(void);
+
+/* Reset the watchdog timer. Does not return until the timer has been
+ * reset and does not schedule future resets. */
+void ipmi_wdt_final_reset(void);
+
#endif
diff --git a/platforms/astbmc/common.c b/platforms/astbmc/common.c
index 993ac4c..336d275 100644
--- a/platforms/astbmc/common.c
+++ b/platforms/astbmc/common.c
@@ -51,6 +51,7 @@ void astbmc_init(void)
/* Register the BT interface with the IPMI layer */
bt_init();
+ ipmi_wdt_init();
ipmi_rtc_init();
ipmi_opal_init();
ipmi_fru_init(0x01);
diff --git a/platforms/astbmc/palmetto.c b/platforms/astbmc/palmetto.c
index a0030e8..b9ef4a4 100644
--- a/platforms/astbmc/palmetto.c
+++ b/platforms/astbmc/palmetto.c
@@ -51,4 +51,5 @@ DECLARE_PLATFORM(palmetto) = {
.cec_power_down = astbmc_ipmi_power_down,
.cec_reboot = astbmc_ipmi_reboot,
.elog_commit = ipmi_elog_commit,
+ .exit = ipmi_wdt_final_reset,
};
--
1.8.3.2
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