Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751855AbaANLCb (ORCPT ); Tue, 14 Jan 2014 06:02:31 -0500 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:37390 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751760AbaANLC1 (ORCPT ); Tue, 14 Jan 2014 06:02:27 -0500 Subject: [PATCH v1] powernv/cpuidle: Back-end cpuidle driver for powernv platform. To: linux-pm@vger.kernel.org, benh@kernel.crashing.org, daniel.lezcano@linaro.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com, preeti@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org From: Deepthi Dharwar Date: Tue, 14 Jan 2014 16:32:40 +0530 Message-ID: <20140114110229.4091.25232.stgit@deepthi.in.ibm.com> In-Reply-To: <20140114110157.4091.80684.stgit@deepthi.in.ibm.com> References: <20140114110157.4091.80684.stgit@deepthi.in.ibm.com> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14011411-8878-0000-0000-00000A73F658 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Following patch ports the cpuidle framework for powernv platform and also implements a cpuidle back-end powernv idle driver calling on to power7_nap and snooze idle states. Signed-off-by: Deepthi Dharwar --- arch/powerpc/platforms/powernv/setup.c | 13 ++ drivers/cpuidle/Kconfig.powerpc | 9 ++ drivers/cpuidle/Makefile | 1 drivers/cpuidle/cpuidle-powernv.c | 169 ++++++++++++++++++++++++++++++++ 4 files changed, 191 insertions(+), 1 deletion(-) create mode 100644 drivers/cpuidle/cpuidle-powernv.c diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c index 19884b2..764a14e 100644 --- a/arch/powerpc/platforms/powernv/setup.c +++ b/arch/powerpc/platforms/powernv/setup.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -214,6 +215,16 @@ static int __init pnv_probe(void) return 1; } +void powernv_idle(void) +{ + /* Hook to cpuidle framework if available, else + * call on default platform idle code + */ + if (cpuidle_idle_call()) { + power7_idle(); + } +} + define_machine(powernv) { .name = "PowerNV", .probe = pnv_probe, @@ -223,7 +234,7 @@ define_machine(powernv) { .show_cpuinfo = pnv_show_cpuinfo, .progress = pnv_progress, .machine_shutdown = pnv_shutdown, - .power_save = power7_idle, + .power_save = powernv_idle, .calibrate_decr = generic_calibrate_decr, #ifdef CONFIG_KEXEC .kexec_cpu_down = pnv_kexec_cpu_down, diff --git a/drivers/cpuidle/Kconfig.powerpc b/drivers/cpuidle/Kconfig.powerpc index 8147de5..66c3a09 100644 --- a/drivers/cpuidle/Kconfig.powerpc +++ b/drivers/cpuidle/Kconfig.powerpc @@ -9,3 +9,12 @@ config PSERIES_CPUIDLE help Select this option to enable processor idle state management through cpuidle subsystem. + +config POWERNV_CPUIDLE + bool "Cpuidle driver for powernv platforms" + depends on CPU_IDLE + depends on PPC_POWERNV + default y + help + Select this option to enable processor idle state management + through cpuidle subsystem. diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index a6331ad..f71ae1b 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -17,3 +17,4 @@ obj-$(CONFIG_ARM_AT91_CPUIDLE) += cpuidle-at91.o ############################################################################### # POWERPC drivers obj-$(CONFIG_PSERIES_CPUIDLE) += cpuidle-pseries.o +obj-$(CONFIG_POWERNV_CPUIDLE) += cpuidle-powernv.o diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c new file mode 100644 index 0000000..78fd174 --- /dev/null +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -0,0 +1,169 @@ +/* + * cpuidle-powernv - idle state cpuidle driver. + * Adapted from drivers/cpuidle/cpuidle-pseries + * + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +struct cpuidle_driver powernv_idle_driver = { + .name = "powernv_idle", + .owner = THIS_MODULE, +}; + +static int max_idle_state; +static struct cpuidle_state *cpuidle_state_table; + +static int snooze_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + local_irq_enable(); + set_thread_flag(TIF_POLLING_NRFLAG); + + while (!need_resched()) { + HMT_low(); + HMT_very_low(); + } + + HMT_medium(); + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb(); + return index; +} + +static int nap_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + power7_idle(); + return index; +} + +/* + * States for dedicated partition case. + */ +static struct cpuidle_state powernv_states[] = { + { /* Snooze */ + .name = "snooze", + .desc = "snooze", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 0, + .target_residency = 0, + .enter = &snooze_loop }, + { /* NAP */ + .name = "NAP", + .desc = "NAP", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 10, + .target_residency = 100, + .enter = &nap_loop }, +}; + +static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n, + unsigned long action, void *hcpu) +{ + int hotcpu = (unsigned long)hcpu; + struct cpuidle_device *dev = + per_cpu(cpuidle_devices, hotcpu); + + if (dev && cpuidle_get_driver()) { + switch (action) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + cpuidle_pause_and_lock(); + cpuidle_enable_device(dev); + cpuidle_resume_and_unlock(); + break; + + case CPU_DEAD: + case CPU_DEAD_FROZEN: + cpuidle_pause_and_lock(); + cpuidle_disable_device(dev); + cpuidle_resume_and_unlock(); + break; + + default: + return NOTIFY_DONE; + } + } + return NOTIFY_OK; +} + +static struct notifier_block setup_hotplug_notifier = { + .notifier_call = powernv_cpuidle_add_cpu_notifier, +}; + +/* + * powernv_cpuidle_driver_init() + */ +static int powernv_cpuidle_driver_init(void) +{ + int idle_state; + struct cpuidle_driver *drv = &powernv_idle_driver; + + drv->state_count = 0; + + for (idle_state = 0; idle_state < max_idle_state; ++idle_state) { + /* Is the state not enabled? */ + if (cpuidle_state_table[idle_state].enter == NULL) + continue; + + drv->states[drv->state_count] = /* structure copy */ + cpuidle_state_table[idle_state]; + + drv->state_count += 1; + } + + return 0; +} + +/* + * powernv_idle_probe() + * Choose state table for shared versus dedicated partition + */ +static int powernv_idle_probe(void) +{ + + if (cpuidle_disable != IDLE_NO_OVERRIDE) + return -ENODEV; + + if (firmware_has_feature(FW_FEATURE_OPALv3)) { + cpuidle_state_table = powernv_states; + max_idle_state = ARRAY_SIZE(powernv_states); + } else + return -ENODEV; + + return 0; +} + +static int __init powernv_processor_idle_init(void) +{ + int retval; + + retval = powernv_idle_probe(); + if (retval) + return retval; + + powernv_cpuidle_driver_init(); + retval = cpuidle_register(&powernv_idle_driver, NULL); + if (retval) { + printk(KERN_DEBUG "Registration of powernv driver failed.\n"); + return retval; + } + + register_cpu_notifier(&setup_hotplug_notifier); + printk(KERN_DEBUG "powernv_idle_driver registered\n"); + return 0; +} + +device_initcall(powernv_processor_idle_init); -- 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/