From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp02.au.ibm.com (e23smtp02.au.ibm.com [202.81.31.144]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id A72861A0D1C for ; Sat, 2 May 2015 21:15:24 +1000 (AEST) Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sat, 2 May 2015 21:15:22 +1000 Received: from d23relay10.au.ibm.com (d23relay10.au.ibm.com [9.190.26.77]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id D54563578048 for ; Sat, 2 May 2015 21:15:19 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t42BFAMg37093396 for ; Sat, 2 May 2015 21:15:19 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t42BELol022238 for ; Sat, 2 May 2015 21:14:21 +1000 Message-ID: <5544B179.1050901@linux.vnet.ibm.com> Date: Sat, 02 May 2015 16:44:01 +0530 From: Neelesh Gupta MIME-Version: 1.0 To: Vipin K Parashar , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH] powerpc/powernv: Add poweroff (EPOW, DPO) events support for PowerNV platform References: <1430374028-32181-1-git-send-email-vipin@linux.vnet.ibm.com> In-Reply-To: <1430374028-32181-1-git-send-email-vipin@linux.vnet.ibm.com> Content-Type: multipart/alternative; boundary="------------040008030303060900050405" Cc: stewart@linux.vnet.ibm.com, joel@jms.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is a multi-part message in MIME format. --------------040008030303060900050405 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit On 04/30/2015 11:37 AM, Vipin K Parashar wrote: > diff --git a/arch/powerpc/platforms/powernv/opal-poweroff-events.c b/arch/powerpc/platforms/powernv/opal-poweroff-events.c > new file mode 100644 > index 0000000..9b169e2 > --- /dev/null > +++ b/arch/powerpc/platforms/powernv/opal-poweroff-events.c > @@ -0,0 +1,358 @@ > +/* > + * PowerNV poweroff events support > + * > + * Copyright 2015 IBM Corp. > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public License > + * as published by the Free Software Foundation; either version > + * 2 of the License, or (at your option) any later version. > + */ > + > +#define pr_fmt(fmt) "POWEROFF_EVENT: " fmt > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* System EPOW status */ > +u32 epow_status[OPAL_MAX_EPOW_CLASSES]; > +int num_epow_classes; static > + > +/* EPOW event timer and corresponding locks */ > +static struct timer_list epow_timer; > +static DEFINE_SPINLOCK(epow_timer_spinlock); > + > +/* EPOW, DPO event status values */ > +#define DPO_DETECTED 1 > +#define EPOW_DETECTED 1 > + > +/* EPOW events supported */ > +#define EPOW_POWER_UPS 0 > +#define EPOW_POWER_UPS_LOW 1 > +#define EPOW_TEMP_HIGH_AMB 2 > +#define EPOW_TEMP_CRIT_AMB 3 > +#define EPOW_TEMP_HIGH_INT 4 > +#define EPOW_TEMP_CRIT_INT 5 > +#define MAX_EPOW_EVENTS 6 > + > +/* EPOW events description */ > +static const char * const epow_events_map[] = { > + [EPOW_POWER_UPS] = "UPS", > + [EPOW_POWER_UPS_LOW] = "UPS-low", > + [EPOW_TEMP_HIGH_AMB] = "high-ambient-temp", > + [EPOW_TEMP_CRIT_AMB] = "crit-ambient-temp", > + [EPOW_TEMP_HIGH_INT] = "high-internal-temp", > + [EPOW_TEMP_CRIT_INT] = "crit-internal-temp", > +}; > + > +/* EPOW events timeout values */ > +static int epow_timeout[MAX_EPOW_EVENTS]; > + > +/* > + * TODO: Export various event timeout values via device tree. > + * Zero timeout value for any event suggests that it needs > + * immediate shutdown. > + */ > +#define TIMEOUT_EPOW_POWER_UPS 450 > +#define TIMEOUT_EPOW_TEMP_HIGH_AMB 450 > + > +/* > + * Get various EPOW event timeouts. > + * TODO: For now hardcoding timeout values but they need to be > + * obtained via firmware device-tree. > + */ > +void get_epow_timeouts(void) static ? > +{ > + epow_timeout[EPOW_POWER_UPS] = TIMEOUT_EPOW_POWER_UPS; > + epow_timeout[EPOW_TEMP_HIGH_AMB] = TIMEOUT_EPOW_TEMP_HIGH_AMB; What about the timeout values for other cases ? don't see assigned anywhere but used in the process_epow() function.. > +} > + > +/* EPOW poweroff function. */ > +static void epow_poweroff(unsigned long event) > +{ > + pr_info("Powering off system due to %s EPOW event\n", > + epow_events_map[event]); > + orderly_poweroff(true); > +} > + > +/* Start EPOW poweroff timer */ > +static void start_epow_timer(unsigned long event, int32_t timeout) 'event' is of type 'int' which you are passing.. > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&epow_timer_spinlock, flags); > + /* Check for already running epow poweroff timer */ > + if (timer_pending(&epow_timer)) { > + /* Timer for same event */ > + if (epow_timer.data == event) { > + spin_unlock_irqrestore(&epow_timer_spinlock, flags); > + return; > + } > + > + /* Timer with early poweroff timeout */ > + if (epow_timer.expires < (jiffies + timeout * HZ)) { Should it also return for the equal condition ? if (epow_timer.expires <= (jiffies + timeout * HZ)) > + event = epow_timer.data; > + spin_unlock_irqrestore(&epow_timer_spinlock, flags); > + pr_info("Poweroff already scheduled for %s EPOW event " > + "with earlier timeout.\n", > + epow_events_map[event]); > + return; > + } > + } > + > + /* Start a new timer/modify existing timer with new timeout value */ > + epow_timer.data = event; > + mod_timer(&epow_timer, jiffies + timeout * HZ); > + spin_unlock_irqrestore(&epow_timer_spinlock, flags); > + pr_info("Scheduled system poweroff due to %s EPOW event " > + "after %d seconds\n", epow_events_map[event], timeout); > +} > + > +/* Stop poweroff timer */ > +static void stop_epow_timer(void) > +{ > + int rc; > + unsigned long flags; > + > + spin_lock_irqsave(&epow_timer_spinlock, flags); > + rc = del_timer(&epow_timer); > + spin_unlock_irqrestore(&epow_timer_spinlock, flags); > + > + if (rc) > + pr_info("Poweroff timer deactivated\n"); > +} > + > +/* Get DPO status */ > +static int get_dpo_status(int32_t *dpo_timeout) > +{ > + int rc; > + __be32 opal_dpo_timeout; > + > + rc = opal_get_dpo_status(&opal_dpo_timeout); > + if (rc == OPAL_WRONG_STATE) { > + *dpo_timeout = 0; > + return 0; > + } > + > + *dpo_timeout = be32_to_cpu(opal_dpo_timeout); > + return DPO_DETECTED; > +} > + > +/* Process DPO event */ > +void process_dpo(void) static function ? > +{ > + pr_info("Powering off system due to poweroff request.\n"); > + orderly_poweroff(true); > +} > + > +/* Get EPOW status */ > +static int get_epow_status(void) > +{ > + int i; > + bool epow_detected = false; > + > + __be32 opal_epow_status[OPAL_MAX_EPOW_CLASSES]; > + __be32 opal_epow_classes; > + > + opal_epow_classes = cpu_to_be32(OPAL_MAX_EPOW_CLASSES); > + for (i = 0; i < OPAL_MAX_EPOW_CLASSES; i++) > + opal_epow_status[i] = cpu_to_be32(0); > + > + /* Get EPOW events information from OPAL */ > + opal_get_epow_status(opal_epow_status, &opal_epow_classes); > + > + /* Copy EPOW status */ > + memset(epow_status, 0, sizeof(epow_status[0] * OPAL_MAX_EPOW_CLASSES)); > + num_epow_classes = be32_to_cpu(opal_epow_classes); > + for (i = 0; i < num_epow_classes; i++) { > + epow_status[i] = be32_to_cpu(opal_epow_status[i]); > + if (epow_status[i]) > + epow_detected = true; > + } > + > + pr_info("EPOW classes supported OPAL = %d, Host = %d " > + "EPOW Status = 0x%x, 0x%x, 0x%x\n", > + num_epow_classes, OPAL_MAX_EPOW_CLASSES, > + epow_status[0], epow_status[1], epow_status[2]); > + > + if (epow_detected) > + return EPOW_DETECTED; > + > + return 0; > +} > + > +/* Process EPOW information */ > +void process_epow(void) > +{ > + int i, timeout = 0, event = -1; > + bool epow_normal = false; > + > + /* Check for EPOW return to normal state */ > + for (i = 0; i < OPAL_MAX_EPOW_CLASSES; i++) { s/OPAL_MAX_EPOW_CLASSES/num_epow_classes > + if (epow_status[i]) > + break; > + } > + > + if (i == OPAL_MAX_EPOW_CLASSES) > + epow_normal = true; > + > + /* Cancel any pending shutdown timer due to EPOW normal state.*/ > + if (epow_normal) { > + stop_epow_timer(); > + return; > + } > + > + /* Determine EPOW events and poweroff timeouts */ > + if (epow_status[OPAL_EPOW_POWER] & OPAL_EPOW_POWER_UPS) { > + pr_info("EPOW due to system running on UPS power\n"); > + event = EPOW_POWER_UPS; > + timeout = epow_timeout[EPOW_POWER_UPS]; > + } > + > + if (epow_status[OPAL_EPOW_POWER] & OPAL_EPOW_POWER_UPS_LOW) { > + pr_info("EPOW due to system running on UPS power " > + "with low battery\n"); > + event = EPOW_POWER_UPS_LOW; > + timeout = epow_timeout[EPOW_POWER_UPS_LOW]; > + } > + > + if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_HIGH_AMB) { > + pr_info("EPOW due to high ambient temperature\n"); > + event = EPOW_TEMP_HIGH_AMB; > + timeout = epow_timeout[EPOW_TEMP_HIGH_AMB]; > + } > + > + if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_CRIT_AMB) { > + pr_info("EPOW due to critical ambient temperature\n"); > + event = EPOW_TEMP_CRIT_AMB; > + timeout = epow_timeout[EPOW_TEMP_CRIT_AMB]; > + } > + > + if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_HIGH_INT) { > + pr_info("EPOW due to high internal temperature\n"); > + event = EPOW_TEMP_HIGH_INT; > + timeout = epow_timeout[EPOW_TEMP_HIGH_INT]; > + } > + > + if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_CRIT_INT) { > + pr_info("EPOW due to critical internal temperature\n"); > + event = EPOW_TEMP_CRIT_INT; > + timeout = epow_timeout[EPOW_TEMP_CRIT_INT]; > + } 'event' & 'timeout' values are getting updated after each check, I guess for multiple types of epow cases.. Can it be changed to if-elseif-if construct.. and check based on the criticality ...? > + > + if (event == -1) { > + pr_err("Unknown EPOW event\n"); > + return; > + } > + > + /* Start EPOW poweroff timer */ > + start_epow_timer(event, timeout); > +} > + > +/* Check for any existing EPOW, DPO events and process them, if existing */ > +static void process_existing_poweroff_events(void) > +{ > + int rc; > + int32_t dpo_timeout; > + > + /* Check for any existing DPO event */ > + rc = get_dpo_status(&dpo_timeout); > + if (rc == DPO_DETECTED) { > + pr_info("Existing DPO event detected\n"); > + process_dpo(); > + return; > + } else > + pr_info("No existing DPO event detected\n"); > + > + /* Check for any existing EPOW event */ > + rc = get_epow_status(); > + if (rc == EPOW_DETECTED) { > + pr_info("Existing EPOW event detected.\n"); > + process_epow(); > + } else > + pr_info("No existing EPOW event detected\n"); > + > +} > + > +/* Platform EPOW message received */ > +static int opal_epow_event(struct notifier_block *nb, > + unsigned long msg_type, void *msg) > +{ > + pr_info("EPOW event received\n"); > + > + /* Get EPOW event details */ > + get_epow_status(); > + > + /* Process EPOW event information */ > + process_epow(); > + > + return 0; > +} > + > + > +/* Platform DPO message received */ > +static int opal_dpo_event(struct notifier_block *nb, > + unsigned long msg_type, void *msg) > +{ > + pr_info("DPO event received.\n"); > + process_dpo(); > + > + return 0; > +} > + > + > +/* OPAL EPOW event notifier block */ > +static struct notifier_block opal_epow_nb = { > + .notifier_call = opal_epow_event, > + .next = NULL, > + .priority = 0, > +}; > + > +/* OPAL DPO event notifier block */ > +static struct notifier_block opal_dpo_nb = { > + .notifier_call = opal_dpo_event, > + .next = NULL, > + .priority = 0, > +}; > + > +/* Poweroff events init */ > +static int opal_poweroff_events_init(void) Use '__init' macro for the initialization function. > +{ > + int ret; > + > + /* Initialize poweroff timer */ > + init_timer(&epow_timer); > + epow_timer.function = epow_poweroff; > + > + /* Get EPOW event timeout values */ > + get_epow_timeouts(); > + > + /* Check for any existing EPOW or DPO events. */ > + process_existing_poweroff_events(); > + > + /* Register EPOW event notifier */ > + ret = opal_message_notifier_register(OPAL_MSG_EPOW, &opal_epow_nb); > + if (ret) { > + pr_err("EPOW event notifier registration failed\n"); > + return ret; > + } > + > + /* Register DPO event notifier */ > + ret = opal_message_notifier_register(OPAL_MSG_DPO, &opal_dpo_nb); > + if (ret) { > + pr_err("DPO event notifier registration failed\n"); > + opal_notifier_unregister(&opal_epow_nb); opal_message_notifier_unregister() instead. plus delete the timer too. Regards, Neelesh. > + return ret; > + } > + > + > + pr_info("OPAL poweroff events support initialized\n"); > + > + return 0; > +} > + > +machine_subsys_initcall(powernv, opal_poweroff_events_init); > diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S > index a7ade94..5d3c8e3 100644 > --- a/arch/powerpc/platforms/powernv/opal-wrappers.S > +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S > @@ -249,6 +249,7 @@ OPAL_CALL(opal_pci_reinit, OPAL_PCI_REINIT); > OPAL_CALL(opal_pci_mask_pe_error, OPAL_PCI_MASK_PE_ERROR); > OPAL_CALL(opal_set_slot_led_status, OPAL_SET_SLOT_LED_STATUS); > OPAL_CALL(opal_get_epow_status, OPAL_GET_EPOW_STATUS); > +OPAL_CALL(opal_get_dpo_status, OPAL_GET_DPO_STATUS); > OPAL_CALL(opal_set_system_attention_led, OPAL_SET_SYSTEM_ATTENTION_LED); > OPAL_CALL(opal_pci_next_error, OPAL_PCI_NEXT_ERROR); > OPAL_CALL(opal_pci_poll, OPAL_PCI_POLL); --------------040008030303060900050405 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 7bit

On 04/30/2015 11:37 AM, Vipin K Parashar wrote:
diff --git a/arch/powerpc/platforms/powernv/opal-poweroff-events.c b/arch/powerpc/platforms/powernv/opal-poweroff-events.c
new file mode 100644
index 0000000..9b169e2
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-poweroff-events.c
@@ -0,0 +1,358 @@
+/*
+ * PowerNV poweroff events support
+ *
+ * Copyright 2015 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt)	"POWEROFF_EVENT: "    fmt
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/reboot.h>
+#include <asm/opal.h>
+#include <asm/machdep.h>
+
+/* System EPOW status */
+u32 epow_status[OPAL_MAX_EPOW_CLASSES];
+int num_epow_classes;

static

+
+/* EPOW event timer and corresponding locks */
+static struct timer_list epow_timer;
+static DEFINE_SPINLOCK(epow_timer_spinlock);
+
+/* EPOW, DPO event status values */
+#define	DPO_DETECTED	1
+#define	EPOW_DETECTED	1
+
+/* EPOW events supported */
+#define EPOW_POWER_UPS          0
+#define EPOW_POWER_UPS_LOW      1
+#define EPOW_TEMP_HIGH_AMB      2
+#define EPOW_TEMP_CRIT_AMB      3
+#define EPOW_TEMP_HIGH_INT      4
+#define EPOW_TEMP_CRIT_INT      5
+#define MAX_EPOW_EVENTS		6
+
+/* EPOW events description */
+static const char * const epow_events_map[] = {
+	[EPOW_POWER_UPS]	= "UPS",
+	[EPOW_POWER_UPS_LOW]	= "UPS-low",
+	[EPOW_TEMP_HIGH_AMB]	= "high-ambient-temp",
+	[EPOW_TEMP_CRIT_AMB]	= "crit-ambient-temp",
+	[EPOW_TEMP_HIGH_INT]	= "high-internal-temp",
+	[EPOW_TEMP_CRIT_INT]	= "crit-internal-temp",
+};
+
+/* EPOW events timeout values */
+static int epow_timeout[MAX_EPOW_EVENTS];
+
+/*
+ * TODO: Export various event timeout values via device tree.
+ *  Zero timeout value for any event suggests that it needs
+ *  immediate shutdown.
+ */
+#define TIMEOUT_EPOW_POWER_UPS		450
+#define TIMEOUT_EPOW_TEMP_HIGH_AMB	450
+
+/*
+ * Get various EPOW event timeouts.
+ * TODO: For now hardcoding timeout values but they need to be
+ * obtained via firmware device-tree.
+ */
+void get_epow_timeouts(void)

static ?

+{
+	epow_timeout[EPOW_POWER_UPS] = TIMEOUT_EPOW_POWER_UPS;
+	epow_timeout[EPOW_TEMP_HIGH_AMB] = TIMEOUT_EPOW_TEMP_HIGH_AMB;

What about the timeout values for other cases ? don't see assigned
anywhere but used in the process_epow() function..

+}
+
+/* EPOW poweroff function. */
+static void epow_poweroff(unsigned long event)
+{
+	pr_info("Powering off system due to %s EPOW event\n",
+				epow_events_map[event]);
+	orderly_poweroff(true);
+}
+
+/* Start EPOW poweroff timer */
+static void start_epow_timer(unsigned long event, int32_t timeout)

'event' is of type 'int' which you are passing..

+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&epow_timer_spinlock, flags);
+	/* Check for already running epow poweroff timer */
+	if (timer_pending(&epow_timer)) {
+		/* Timer for same event */
+		if (epow_timer.data == event) {
+			spin_unlock_irqrestore(&epow_timer_spinlock, flags);
+			return;
+		}
+
+		/* Timer with early poweroff timeout */
+		if (epow_timer.expires < (jiffies + timeout * HZ)) {

Should it also return for the equal condition ?
if (epow_timer.expires <= (jiffies + timeout * HZ))
+			event = epow_timer.data;
+			spin_unlock_irqrestore(&epow_timer_spinlock, flags);
+			pr_info("Poweroff already scheduled for %s EPOW event "
+					"with earlier timeout.\n",
+					epow_events_map[event]);
+			return;
+		}
+	}
+
+	/* Start a new timer/modify existing timer with new timeout value */
+	epow_timer.data = event;
+	mod_timer(&epow_timer, jiffies + timeout  * HZ);
+	spin_unlock_irqrestore(&epow_timer_spinlock, flags);
+	pr_info("Scheduled system poweroff due to %s EPOW event "
+			"after %d seconds\n", epow_events_map[event], timeout);
+}
+
+/* Stop poweroff timer */
+static void stop_epow_timer(void)
+{
+	int rc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&epow_timer_spinlock, flags);
+	rc = del_timer(&epow_timer);
+	spin_unlock_irqrestore(&epow_timer_spinlock, flags);
+
+	if (rc)
+		pr_info("Poweroff timer deactivated\n");
+}
+
+/* Get DPO status */
+static int get_dpo_status(int32_t *dpo_timeout)
+{
+	int rc;
+	__be32 opal_dpo_timeout;
+
+	rc = opal_get_dpo_status(&opal_dpo_timeout);
+	if (rc == OPAL_WRONG_STATE) {
+		*dpo_timeout = 0;
+		return 0;
+	}
+
+	*dpo_timeout = be32_to_cpu(opal_dpo_timeout);
+	return DPO_DETECTED;
+}
+
+/* Process DPO event */
+void process_dpo(void)

static function ?

+{
+	pr_info("Powering off system due to poweroff request.\n");
+	orderly_poweroff(true);
+}
+
+/* Get EPOW status */
+static int get_epow_status(void)
+{
+	int i;
+	bool epow_detected = false;
+
+	__be32 opal_epow_status[OPAL_MAX_EPOW_CLASSES];
+	__be32 opal_epow_classes;
+
+	opal_epow_classes = cpu_to_be32(OPAL_MAX_EPOW_CLASSES);
+	for (i = 0; i < OPAL_MAX_EPOW_CLASSES; i++)
+		opal_epow_status[i] = cpu_to_be32(0);
+
+	/* Get EPOW events information from OPAL */
+	opal_get_epow_status(opal_epow_status, &opal_epow_classes);
+
+	/* Copy EPOW status */
+	memset(epow_status, 0, sizeof(epow_status[0] * OPAL_MAX_EPOW_CLASSES));
+	num_epow_classes = be32_to_cpu(opal_epow_classes);
+	for (i = 0; i < num_epow_classes; i++) {
+		epow_status[i] = be32_to_cpu(opal_epow_status[i]);
+		if (epow_status[i])
+			epow_detected = true;
+	}
+
+	pr_info("EPOW classes supported OPAL = %d, Host = %d "
+			"EPOW Status = 0x%x, 0x%x, 0x%x\n",
+			num_epow_classes, OPAL_MAX_EPOW_CLASSES,
+			epow_status[0], epow_status[1], epow_status[2]);
+
+	if (epow_detected)
+		return EPOW_DETECTED;
+
+	return 0;
+}
+
+/* Process EPOW information */
+void process_epow(void)
+{
+	int i, timeout = 0, event = -1;
+	bool epow_normal = false;
+
+	/* Check for EPOW return to normal state */
+	for (i = 0; i < OPAL_MAX_EPOW_CLASSES; i++) {

s/OPAL_MAX_EPOW_CLASSES/num_epow_classes

+		if (epow_status[i])
+			break;
+	}
+
+	if (i == OPAL_MAX_EPOW_CLASSES)
+		epow_normal = true;
+
+	/* Cancel any pending shutdown timer due to EPOW normal state.*/
+	if (epow_normal) {
+		stop_epow_timer();
+		return;
+	}
+
+	/* Determine EPOW events and poweroff timeouts */
+	if (epow_status[OPAL_EPOW_POWER] & OPAL_EPOW_POWER_UPS) {
+		pr_info("EPOW due to system running on UPS power\n");
+		event = EPOW_POWER_UPS;
+		timeout = epow_timeout[EPOW_POWER_UPS];
+	}
+
+	if (epow_status[OPAL_EPOW_POWER] & OPAL_EPOW_POWER_UPS_LOW) {
+		pr_info("EPOW due to system running on UPS power "
+				"with low battery\n");
+		event = EPOW_POWER_UPS_LOW;
+		timeout = epow_timeout[EPOW_POWER_UPS_LOW];
+	}
+
+	if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_HIGH_AMB) {
+		pr_info("EPOW due to high ambient temperature\n");
+		event = EPOW_TEMP_HIGH_AMB;
+		timeout = epow_timeout[EPOW_TEMP_HIGH_AMB];
+	}
+
+	if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_CRIT_AMB) {
+		pr_info("EPOW due to critical ambient temperature\n");
+		event = EPOW_TEMP_CRIT_AMB;
+		timeout = epow_timeout[EPOW_TEMP_CRIT_AMB];
+	}
+
+	if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_HIGH_INT) {
+		pr_info("EPOW due to high internal temperature\n");
+		event = EPOW_TEMP_HIGH_INT;
+		timeout = epow_timeout[EPOW_TEMP_HIGH_INT];
+	}
+
+	if (epow_status[OPAL_EPOW_TEMP] & OPAL_EPOW_TEMP_CRIT_INT) {
+		pr_info("EPOW due to critical internal temperature\n");
+		event = EPOW_TEMP_CRIT_INT;
+		timeout = epow_timeout[EPOW_TEMP_CRIT_INT];
+	}

'event' & 'timeout' values are getting updated after each check, I guess
for multiple types of epow cases.. Can it be changed to if-elseif-if construct..
and check based on the criticality ...?

+
+	if (event == -1) {
+		pr_err("Unknown EPOW event\n");
+		return;
+	}
+
+	/* Start EPOW poweroff timer */
+	start_epow_timer(event, timeout);
+}
+
+/* Check for any existing EPOW, DPO events and process them, if existing */
+static void process_existing_poweroff_events(void)
+{
+	int rc;
+	int32_t dpo_timeout;
+
+	/* Check for any existing DPO event */
+	rc = get_dpo_status(&dpo_timeout);
+	if (rc == DPO_DETECTED) {
+		pr_info("Existing DPO event detected\n");
+		process_dpo();
+		return;
+	 } else
+		pr_info("No existing DPO event detected\n");
+
+	/* Check for any existing EPOW event */
+	rc = get_epow_status();
+	if (rc == EPOW_DETECTED) {
+		pr_info("Existing EPOW event detected.\n");
+		process_epow();
+	} else
+		pr_info("No existing EPOW event detected\n");
+
+}
+
+/* Platform EPOW message received */
+static int opal_epow_event(struct notifier_block *nb,
+			unsigned long msg_type, void *msg)
+{
+	pr_info("EPOW event received\n");
+
+	/* Get EPOW event details */
+	get_epow_status();
+
+	/* Process EPOW event information */
+	process_epow();
+
+	return 0;
+}
+
+
+/* Platform DPO message received */
+static int opal_dpo_event(struct notifier_block *nb,
+				unsigned long msg_type, void *msg)
+{
+	pr_info("DPO event received.\n");
+	process_dpo();
+
+	return 0;
+}
+
+
+/* OPAL EPOW event notifier block */
+static struct notifier_block opal_epow_nb = {
+	.notifier_call  = opal_epow_event,
+	.next           = NULL,
+	.priority       = 0,
+};
+
+/* OPAL DPO event notifier block */
+static struct notifier_block opal_dpo_nb = {
+	.notifier_call  = opal_dpo_event,
+	.next           = NULL,
+	.priority       = 0,
+};
+
+/* Poweroff events init */
+static int opal_poweroff_events_init(void)

Use '__init' macro for the initialization function.

+{
+	int ret;
+
+	/* Initialize poweroff timer */
+	init_timer(&epow_timer);
+	epow_timer.function = epow_poweroff;
+
+	/* Get EPOW event timeout values */
+	get_epow_timeouts();
+
+	/* Check for any existing EPOW or DPO events. */
+	process_existing_poweroff_events();
+
+	/* Register EPOW event notifier */
+	ret = opal_message_notifier_register(OPAL_MSG_EPOW, &opal_epow_nb);
+	if (ret) {
+		pr_err("EPOW event notifier registration failed\n");
+		return ret;
+	}
+
+	/* Register DPO event notifier */
+	ret = opal_message_notifier_register(OPAL_MSG_DPO, &opal_dpo_nb);
+	if (ret) {
+		pr_err("DPO event notifier registration failed\n");
+		opal_notifier_unregister(&opal_epow_nb);

opal_message_notifier_unregister() instead.
plus delete the timer too.

Regards,
Neelesh.

 
+		return ret;
+	}
+
+
+	pr_info("OPAL poweroff events support initialized\n");
+
+	return 0;
+}
+
+machine_subsys_initcall(powernv, opal_poweroff_events_init);
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index a7ade94..5d3c8e3 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -249,6 +249,7 @@ OPAL_CALL(opal_pci_reinit,			OPAL_PCI_REINIT);
 OPAL_CALL(opal_pci_mask_pe_error,		OPAL_PCI_MASK_PE_ERROR);
 OPAL_CALL(opal_set_slot_led_status,		OPAL_SET_SLOT_LED_STATUS);
 OPAL_CALL(opal_get_epow_status,			OPAL_GET_EPOW_STATUS);
+OPAL_CALL(opal_get_dpo_status,			OPAL_GET_DPO_STATUS);
 OPAL_CALL(opal_set_system_attention_led,	OPAL_SET_SYSTEM_ATTENTION_LED);
 OPAL_CALL(opal_pci_next_error,			OPAL_PCI_NEXT_ERROR);
 OPAL_CALL(opal_pci_poll,			OPAL_PCI_POLL);

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