Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966584AbbDVRGu (ORCPT ); Wed, 22 Apr 2015 13:06:50 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:43510 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966454AbbDVRGs (ORCPT ); Wed, 22 Apr 2015 13:06:48 -0400 From: Shilpasri G Bhat To: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Cc: Shilpasri G Bhat , "Rafael J. Wysocki" , Viresh Kumar , linux-pm@vger.kernel.org Subject: [PATCH 2/2] cpufreq: powernv: Register for OCC related opal_message notification Date: Wed, 22 Apr 2015 22:34:25 +0530 Message-Id: <1429722265-2953-2-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1429722265-2953-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> References: <1429722265-2953-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15042217-0005-0000-0000-000004E80E61 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4244 Lines: 133 OCC is an On-Chip-Controller which takes care of power and thermal safety of the chip. During runtime due to power failure or overtemperature the OCC may throttle the frequencies of the CPUs to remain within the power budget. We want the cpufreq driver to be aware of such situations to be able to report it to the user. We register to opal_message_notifier to receive OCC messages from opal. powernv_cpufreq_throttle_check() reports any frequency throttling and this patch will report the reason or event that caused throttling. We can be throttled if OCC is reset or OCC limits Pmax due to power or thermal reasons. We are also notified of unthrottling after an OCC reset or if OCC restores Pmax on the chip. Signed-off-by: Shilpasri G Bhat CC: "Rafael J. Wysocki" CC: Viresh Kumar CC: linux-pm@vger.kernel.org --- drivers/cpufreq/powernv-cpufreq.c | 70 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index ebef0d8..5718765 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -32,6 +32,7 @@ #include #include #include /* Required for cpu_sibling_mask() in UP configs */ +#include #define POWERNV_MAX_PSTATES 256 #define PMSR_PSAFE_ENABLE (1UL << 30) @@ -40,7 +41,7 @@ #define PMSR_LP(x) ((x >> 48) & 0xFF) static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; -static bool rebooting, throttled; +static bool rebooting, throttled, occ_reset; /* * Note: The set of pstates consists of contiguous integers, the @@ -395,6 +396,72 @@ static struct notifier_block powernv_cpufreq_reboot_nb = { .notifier_call = powernv_cpufreq_reboot_notifier, }; +static char throttle_reason[6][50] = { "No throttling", + "Power Cap", + "Processor Over Temperature", + "Power Supply Failure", + "OverCurrent", + "OCC Reset" + }; + +static int powernv_cpufreq_occ_msg(struct notifier_block *nb, + unsigned long msg_type, void *msg) +{ + struct opal_msg *occ_msg = msg; + uint64_t token; + uint64_t chip_id, reason; + + if (msg_type != OPAL_MSG_OCC) + return 0; + token = be64_to_cpu(occ_msg->params[0]); + switch (token) { + case 0: + occ_reset = true; + /* + * powernv_cpufreq_throttle_check() is called in + * target() callback which can detect the throttle state + * for governors like ondemand. + * But static governors will not call target() often thus + * report throttling here. + */ + if (!throttled) { + throttled = true; + pr_crit("CPU Frequency is throttled\n"); + } + pr_info("OCC in Reset\n"); + break; + case 1: + pr_info("OCC is Loaded\n"); + break; + case 2: + chip_id = be64_to_cpu(occ_msg->params[1]); + reason = be64_to_cpu(occ_msg->params[2]); + if (occ_reset) { + occ_reset = false; + throttled = false; + pr_info("OCC is Active\n"); + /* Sanity check for static governors */ + powernv_cpufreq_throttle_check(smp_processor_id()); + } else if (reason) { + throttled = true; + pr_info("Pmax reduced due to %s on chip %x\n", + throttle_reason[reason], (int)chip_id); + } else { + throttled = false; + pr_info("%s on chip %x\n", + throttle_reason[reason], (int)chip_id); + } + break; + } + return 0; +} + +static struct notifier_block powernv_cpufreq_opal_nb = { + .notifier_call = powernv_cpufreq_occ_msg, + .next = NULL, + .priority = 0, +}; + static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) { struct powernv_smp_call_data freq_data; @@ -430,6 +497,7 @@ static int __init powernv_cpufreq_init(void) } register_reboot_notifier(&powernv_cpufreq_reboot_nb); + opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); return cpufreq_register_driver(&powernv_cpufreq_driver); } module_init(powernv_cpufreq_init); -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/