Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752127AbZKSLbA (ORCPT ); Thu, 19 Nov 2009 06:31:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751854AbZKSLbA (ORCPT ); Thu, 19 Nov 2009 06:31:00 -0500 Received: from cantor.suse.de ([195.135.220.2]:47688 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbZKSLa6 (ORCPT ); Thu, 19 Nov 2009 06:30:58 -0500 From: Thomas Renninger Organization: SUSE Products GmbH To: Dave Jones Subject: [PATCH] ACPI: do not define acpi_processor_get_bios_limit() in processor.h (snd ver) Date: Thu, 19 Nov 2009 12:31:01 +0100 User-Agent: KMail/1.10.3 (Linux/2.6.27.29-0.1-default; KDE/4.1.3; x86_64; ; ) Cc: Alex Chiang , Len Brown , linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org References: <20091117220729.25933.57884.stgit@bob.kio> <20091117221125.25933.71150.stgit@bob.kio> <20091118000909.GB1855@redhat.com> In-Reply-To: <20091118000909.GB1855@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200911191231.02905.trenn@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10990 Lines: 326 Hi, On Wednesday 18 November 2009 01:09:09 Dave Jones wrote: > On Tue, Nov 17, 2009 at 03:11:25PM -0700, Alex Chiang wrote: > > If we provide a definition for acpi_processor_get_bios_limit(), we will > > encounter build errors (multiple definitions of the function) when we > > do not have CONFIG_CPU_FREQ configured. > > > > We've already changed the modules that depend on this function to only > > get built when CONFIG_CPU_FREQ is configured, so removing the definition > > when unconfigured is safe. > > > > Cc: Thomas Renninger > > Cc: Len Brown > > Signed-off-by: Alex Chiang > > --- > > > > include/acpi/processor.h | 5 ----- > > 1 files changed, 0 insertions(+), 5 deletions(-) > > There's 2-3 other fixes pending for the bios_limit patch. Alex removed the function that should have get static inline and that looks like the right fix for two mentioned problems. > For now, I've dropped it from cpufreq.next, until Thomas sends > a rediffed version with the compilation problems fixed. Attached is my old version, merged with Alex's one. Alex drops out as author of the fix by that, hope that's ok with you. I also added a build fix for powernow-k7 if: # CONFIG_X86_POWERNOW_K7_ACPI is not set Instead of always including acpi_processor.h, I added: +#ifdef CONFIG_X86_POWERNOW_K7_ACPI + .bios_limit = acpi_processor_get_bios_limit, +#endif Otherwise I could imagine you run into the next trouble if you enable powernow-k7 (without acpi support) and remove the acpi processor driver. I test compiled the relevant cpufreq drivers on i386 with cpufreq on/off and with CONFIG_X86_POWERNOW_K7_ACPI switched off. I hope that was all? Thanks, Thomas --- ACPI/CPUFREQ: Introduce bios_limit per cpu cpufreq sysfs interface This interface is mainly intended (and implemented) for ACPI _PPC BIOS frequency limitations, but other cpufreq drivers can also use it for similar use-cases. Why is this needed: Currently it's not obvious why cpufreq got limited. People see cpufreq/scaling_max_freq reduced, but this could have happened by: - any userspace prog writing to scaling_max_freq - thermal limitations - hardware (_PPC in ACPI case) limitiations Therefore export bios_limit (in kHz) to: - Point the user that it's the BIOS (broken or intended) which limits frequency - Export it as a sysfs interface for userspace progs. While this was a rarely used feature on laptops, there will appear more and more server implemenations providing "Green IT" features like allowing the service processor to limit the frequency. People want to know about HW/BIOS frequency limitations. All ACPI P-state driven cpufreq drivers are covered with this patch: - powernow-k8 - powernow-k7 - acpi-cpufreq Tested with a patched DSDT which limits the first two cores (_PPC returns 1) via _PPC, exposed by bios_limit: # echo 2200000 >cpu2/cpufreq/scaling_max_freq # cat cpu*/cpufreq/scaling_max_freq 2600000 2600000 2200000 2200000 # #scaling_max_freq shows general user/thermal/BIOS limitations # cat cpu*/cpufreq/bios_limit 2600000 2600000 2800000 2800000 # #bios_limit only shows the HW/BIOS limitation CC: Pallipadi Venkatesh CC: Len Brown CC: davej@codemonkey.org.uk CC: linux@dominikbrodowski.net Signed-off-by: Thomas Renninger diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt index 2a5b850..eeb958b 100644 --- a/Documentation/cpu-freq/user-guide.txt +++ b/Documentation/cpu-freq/user-guide.txt @@ -203,6 +203,17 @@ scaling_cur_freq : Current frequency of the CPU as determined by the frequency the kernel thinks the CPU runs at. +bios_limit : If the BIOS tells the OS to limit a CPU to + lower frequencies, the user can read out the + maximum available frequency from this file. + This typically can happen through (often not + intended) BIOS settings, restrictions + triggered through a service processor or other + BIOS/HW based implementations. + This does not cover thermal ACPI limitations + which can be detected through the generic + thermal driver. + If you have selected the "userspace" governor which allows you to set the CPU operating frequency to a specific value, you can read out the current frequency in diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 8b581d3..d2e7c77 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -764,14 +764,15 @@ static struct freq_attr *acpi_cpufreq_attr[] = { }; static struct cpufreq_driver acpi_cpufreq_driver = { - .verify = acpi_cpufreq_verify, - .target = acpi_cpufreq_target, - .init = acpi_cpufreq_cpu_init, - .exit = acpi_cpufreq_cpu_exit, - .resume = acpi_cpufreq_resume, - .name = "acpi-cpufreq", - .owner = THIS_MODULE, - .attr = acpi_cpufreq_attr, + .verify = acpi_cpufreq_verify, + .target = acpi_cpufreq_target, + .bios_limit = acpi_processor_get_bios_limit, + .init = acpi_cpufreq_cpu_init, + .exit = acpi_cpufreq_cpu_exit, + .resume = acpi_cpufreq_resume, + .name = "acpi-cpufreq", + .owner = THIS_MODULE, + .attr = acpi_cpufreq_attr, }; static int __init acpi_cpufreq_init(void) diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k7.c b/arch/x86/kernel/cpu/cpufreq/powernow-k7.c index d47c775..9a97116 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k7.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k7.c @@ -714,14 +714,17 @@ static struct freq_attr *powernow_table_attr[] = { }; static struct cpufreq_driver powernow_driver = { - .verify = powernow_verify, - .target = powernow_target, - .get = powernow_get, - .init = powernow_cpu_init, - .exit = powernow_cpu_exit, - .name = "powernow-k7", - .owner = THIS_MODULE, - .attr = powernow_table_attr, + .verify = powernow_verify, + .target = powernow_target, + .get = powernow_get, +#ifdef CONFIG_X86_POWERNOW_K7_ACPI + .bios_limit = acpi_processor_get_bios_limit, +#endif + .init = powernow_cpu_init, + .exit = powernow_cpu_exit, + .name = "powernow-k7", + .owner = THIS_MODULE, + .attr = powernow_table_attr, }; static int __init powernow_init(void) diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c index f30d253..a9df944 100644 --- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c +++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c @@ -1398,14 +1398,15 @@ static struct freq_attr *powernow_k8_attr[] = { }; static struct cpufreq_driver cpufreq_amd64_driver = { - .verify = powernowk8_verify, - .target = powernowk8_target, - .init = powernowk8_cpu_init, - .exit = __devexit_p(powernowk8_cpu_exit), - .get = powernowk8_get, - .name = "powernow-k8", - .owner = THIS_MODULE, - .attr = powernow_k8_attr, + .verify = powernowk8_verify, + .target = powernowk8_target, + .bios_limit = acpi_processor_get_bios_limit, + .init = powernowk8_cpu_init, + .exit = __devexit_p(powernowk8_cpu_exit), + .get = powernowk8_get, + .name = "powernow-k8", + .owner = THIS_MODULE, + .attr = powernow_k8_attr, }; /* driver entry point for init */ diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 8ba0ed0..6b4be59 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -167,6 +167,19 @@ int acpi_processor_ppc_has_changed(struct acpi_processor *pr) return cpufreq_update_policy(pr->id); } +int acpi_processor_get_bios_limit(int cpu, unsigned int *limit) +{ + struct acpi_processor *pr; + + pr = per_cpu(processors, cpu); + if (!pr || !pr->performance || !pr->performance->state_count) + return -ENODEV; + *limit = pr->performance->states[pr->performance_platform_limit]. + core_frequency * 1000; + return 0; +} +EXPORT_SYMBOL(acpi_processor_get_bios_limit); + void acpi_processor_ppc_init(void) { if (!cpufreq_register_notifier diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 5b9b1c8..f20668c 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -647,6 +647,21 @@ static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) return policy->governor->show_setspeed(policy, buf); } +/** + * show_scaling_driver - show the current cpufreq HW/BIOS limitation + */ +static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) +{ + unsigned int limit; + int ret; + if (cpufreq_driver->bios_limit) { + ret = cpufreq_driver->bios_limit(policy->cpu, &limit); + if (!ret) + return sprintf(buf, "%u\n", limit); + } + return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); +} + #define define_one_ro(_name) \ static struct freq_attr _name = \ __ATTR(_name, 0444, show_##_name, NULL) @@ -666,6 +681,7 @@ define_one_ro(cpuinfo_transition_latency); define_one_ro(scaling_available_governors); define_one_ro(scaling_driver); define_one_ro(scaling_cur_freq); +define_one_ro(bios_limit); define_one_ro(related_cpus); define_one_ro(affected_cpus); define_one_rw(scaling_min_freq); @@ -905,6 +921,11 @@ static int cpufreq_add_dev_interface(unsigned int cpu, if (ret) goto err_out_kobj_put; } + if (cpufreq_driver->bios_limit) { + ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); + if (ret) + goto err_out_kobj_put; + } spin_lock_irqsave(&cpufreq_driver_lock, flags); for_each_cpu(j, policy->cpus) { diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 740ac3a..8b668ea 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -295,6 +295,7 @@ static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx void acpi_processor_ppc_init(void); void acpi_processor_ppc_exit(void); int acpi_processor_ppc_has_changed(struct acpi_processor *pr); +extern int acpi_processor_get_bios_limit(int cpu, unsigned int *limit); #else static inline void acpi_processor_ppc_init(void) { @@ -316,6 +317,11 @@ static inline int acpi_processor_ppc_has_changed(struct acpi_processor *pr) } return 0; } +static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit) +{ + return -ENODEV; +} + #endif /* CONFIG_CPU_FREQ */ /* in processor_throttling.c */ diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 79a2340..4de02b1 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -232,6 +232,7 @@ struct cpufreq_driver { /* optional */ unsigned int (*getavg) (struct cpufreq_policy *policy, unsigned int cpu); + int (*bios_limit) (int cpu, unsigned int *limit); int (*exit) (struct cpufreq_policy *policy); int (*suspend) (struct cpufreq_policy *policy, pm_message_t pmsg); -- 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/