From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755521Ab3FLHkY (ORCPT ); Wed, 12 Jun 2013 03:40:24 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:43607 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753824Ab3FLHkW (ORCPT ); Wed, 12 Jun 2013 03:40:22 -0400 X-AuditID: cbfee61a-b7f3b6d000006edd-4a-51b825e3d4ea Date: Wed, 12 Jun 2013 09:39:38 +0200 From: Lukasz Majewski To: Viresh Kumar Cc: "Rafael J. Wysocky" , "cpufreq@vger.kernel.org" , Linux PM list , Vincent Guittot , Jonghwa Lee , Myungjoo Ham , linux-kernel , Lukasz Majewski , Andre Przywara , Daniel Lezcano , Kukjin Kim Subject: Re: [PATCH v2 1/3] cpufreq:boost: CPU frequency boost code unification for software and hardware solutions Message-id: <20130612093938.1cf73c9a@amdc308.digital.local> In-reply-to: References: <1370502472-7249-1-git-send-email-l.majewski@samsung.com> <1370941408-29304-1-git-send-email-l.majewski@samsung.com> <1370941408-29304-2-git-send-email-l.majewski@samsung.com> Organization: SPRC Poland X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.10; x86_64-pc-linux-gnu) MIME-version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrHLMWRmVeSWpSXmKPExsVy+t9jAd3HqjsCDWYs0bf483Y5q8XTph/s FvM+y1p0nn3CbNG74CqbxZtH3BaXd81hs/jce4TR4nbjCjaL/oW9TBYdR74xW2z86uHA43Hn 2h42j3XT3jJ79G1ZxejxaHELo8fnTXIBrFFcNimpOZllqUX6dglcGe9W/GIvmF9Y8e/kO/YG xgtBXYycHBICJhJLN35mhLDFJC7cW8/WxcjFISSwiFHi89W7rCAJIYF2JokPe7hAbBYBVYk5 Dw+AxdkE9CQ+333K1MXIwSEioCXx8mYqSC+zwDNmicdf1oDVCAuUSjyZ+ZIdxOYVsJY48WE+ mM0pECxx5dU9ZohlbUwSOxcdYQFJ8AtISrT/+8EMcZGdxLlPG6CaBSV+TL4HVsMMtGzztiZW CFteYvOat8wTGAVnISmbhaRsFpKyBYzMqxhFUwuSC4qT0nMN9YoTc4tL89L1kvNzNzGCY+WZ 1A7GlQ0WhxgFOBiVeHgPmG0PFGJNLCuuzD3EKMHBrCTC+0d4R6AQb0piZVVqUX58UWlOavEh RmkOFiVx3gOt1oFCAumJJanZqakFqUUwWSYOTqkGxhbZW3yKjiwlSimb181I/BsTuE7/0tej deZMl1LNH9lZluzuWXJll2xI5pT1D1tiLCaWh0pu6ig3XN7dsGzVDiMOo06tz4q2YceT2V68 750Z8odzukDDgkvmqtJPVCeKFzxc8eXukhtZV24L3XL2FE2QMtgW9lR8n35zUn0dn33jsvn8 JwSnKrEUZyQaajEXFScCAEZDMKiRAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Viresh, > Hi, > > Change subject to: "cpufreq: Add boost frequency support in core" Ok. > > On 11 June 2013 14:33, Lukasz Majewski wrote: > > This commit adds support for software based frequency boosting. > > No. It adds support for both software and hardware boosting. So just > write: This commit adds boost frequency support in cpufreq core > (Hardware & Software). Ok. > > > Some SoC (like Exynos4 - e.g. 4x12) allow setting frequency above > > its normal condition limits. Such a change shall be only done for a > > short > > s/condition/operation > s/change/mode > s/done/used > Ok. > > time. > > > > Overclocking (boost) support is essentially provided by platform > > dependent cpufreq driver. > > > > This commit unifies support for SW and HW (Intel) over clocking > > solutions in the core cpufreq driver. Previously the "boost" sysfs > > attribute was defined at acpi driver code. > > By default boost is disabled. One global attribute is available at: > > /sys/devices/system/cpu/cpufreq/boost. > > Enter a blank line here. Ok > > > It only shows up when cpufreq driver supports overclocking. > > Under the hood frequencies dedicated for boosting are marked with a > > special flag (CPUFREQ_BOOST_FREQ) at driver's frequency table. > > It is the user's concern to enable/disable overclocking with proper > > call to sysfs. > > Good. > > > Signed-off-by: Lukasz Majewski > > Signed-off-by: Myungjoo Ham > > > > --- ^^^^ [*] this --- was added manually by me. > > Changes for v2: > > - Removal of cpufreq_boost structure and move its fields to > > cpufreq_driver structure > > - Flag to indicate if global boost attribute is already defined > > - Extent the pr_{err|debbug} functions to show current function > > names --- > > You don't have to manually add "---" here. Just keep a blank line > instead. One "---" is added by git automatically. The [*] was added to distinct the changelog from rest of the commit. At least older versions of GIT required this to not include changelog to commit messages. > > > drivers/cpufreq/cpufreq.c | 69 > > ++++++++++++++++++++++++++++++++++++++++++ > > drivers/cpufreq/freq_table.c | 57 > > ++++++++++++++++++++++++++++++++-- include/linux/cpufreq.h | > > 12 ++++++++ 3 files changed, 136 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > > index 1b8a48e..98ba5f1 100644 > > --- a/drivers/cpufreq/cpufreq.c > > +++ b/drivers/cpufreq/cpufreq.c > > @@ -40,6 +40,7 @@ > > * also protects the cpufreq_cpu_data array. > > */ > > static struct cpufreq_driver *cpufreq_driver; > > +static bool cpufreq_boost_sysfs_defined; > > static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); > > #ifdef CONFIG_HOTPLUG_CPU > > /* This one keeps track of the previously set governor of a > > removed CPU */ @@ -315,6 +316,33 @@ > > EXPORT_SYMBOL_GPL(cpufreq_notify_transition); /********************************************************************* > > * SYSFS > > INTERFACE * > > *********************************************************************/ > > +ssize_t show_boost_status(struct kobject *kobj, > > + struct attribute *attr, char *buf) > > +{ > > + return sprintf(buf, "%d\n", cpufreq_driver->boost_en); > > This isn't correct. It shows if cpufreq driver supports boost or > not and it should show if boost is enabled from sysfs when > cpufreq driver supports boost. The cpufreq_driver->low_level_boost() is only valid when cpufreq driver supports boost. Otherwise it is NULL. Thereof you will not see those attributes exported to /sysfs until cpufreq driver supports boost. When "boost" attribute is exported - then it returns state of boosting (if it is enabled or not). > > > +} > > + > > +static ssize_t store_boost_status(struct kobject *kobj, struct > > attribute *attr, > > + const char *buf, size_t count) > > +{ > > + int ret, enable; > > + > > + ret = sscanf(buf, "%d", &enable); > > + if (ret != 1 || enable < 0 || enable > 1) > > + return -EINVAL; > > + > > + if (cpufreq_boost_trigger_state(enable)) { > > + pr_err("%s: Cannot %sable boost!\n", __func__, > > + enable ? "en" : "dis"); > > %sable doesn't look very much readable. Use complete strings: > "enable" and "disable". Ok. > > > + return -EINVAL; > > + } > > + > > + return count; > > +} > > + > > +static struct global_attr global_boost = __ATTR(boost, 0644, > > + show_boost_status, > > + store_boost_status); > > User define_one_global_rw. Ok, will reuse available macros (this code was taken directly from acpi-cpufreq.c file). > > > static struct cpufreq_governor *__find_governor(const char > > *str_governor) { > > @@ -754,6 +782,17 @@ static int cpufreq_add_dev_interface(unsigned > > int cpu, > > Why not do this in cpufreq_register_driver()? Good point. I will move this code to cpufreq_register_driver. > > > goto err_out_kobj_put; > > drv_attr++; > > } > > + if (cpufreq_driver->low_level_boost > > && !cpufreq_boost_sysfs_defined) { > > I thought low_level_boost() is a function which will only be supported > for drivers > using hardware boost feature, like intel. I think that we shall give users some flexibility and don't assume that low_level_boost is only used for one solution/vendor. It is also needed with software controlled boost. Please refer to patch 3/3. > And so we must have used > boost_en here. boost_en has two meanings: 0 - either boost disabled or not supported (when low_level_boost=NULL). 1 - boost is enabled. > > > + ret = sysfs_create_file(cpufreq_global_kobject, > > + &(global_boost.attr)); > > cpufreq_sysfs_create_file(), check > 2361be23666232dbb4851a527f466c4cbf5340fc for details. Ok, I will rebase those changes to newest kernel/git/rafael/linux-pm.git ,branch kernel_pm/pm-cpufreq > > > + if (ret) { > > + pr_err("%s: cannot register global boost > > sysfs file\n", > > + __func__); > > + goto err_out_kobj_put; > > + } > > + cpufreq_boost_sysfs_defined = 1; > > + } > > + > > if (cpufreq_driver->get) { > > ret = sysfs_create_file(&policy->kobj, > > &cpuinfo_cur_freq.attr); if (ret) > > @@ -1853,6 +1892,30 @@ static struct notifier_block __refdata > > cpufreq_cpu_notifier = { }; > > > > /********************************************************************* > > + * > > BOOST * > > + > > *********************************************************************/ > > +int cpufreq_boost_trigger_state(int state) +{ > > + int ret = 0; > > + > > + if (!cpufreq_driver->low_level_boost) > > + return -ENODEV; > > I am certainly not aligned with your design. What's the > use of this field? I had to rewrite a bit :-) patches since we decided to drop struct cpufreq_boost. I've added two fields to cpufreq_driver: - low_level_boost: * When boost is not supported (default) it is set to NULL. This field has two purposes: Indicates if boost is available on the system and provides address of low level callback * When cpufreq driver assigns pointer to this field, it means that it is supported - boost_en: * It shows if boost is enabled or disabled/not supported to the rest of the system. > And please update documentation too for these > new entries in cpufreq_driver structure. Ok I will extend it. > > > + if (cpufreq_driver->boost_en != state) { > > So, you are using boost_en to see if boost is enabled from sysfs? > Then you have put it at wrong place. I check if boost is already enabled. > > I thought there would be three variables: > - cpufreq_driver->boost_supported: boost is enabled for driver For this purpose I check the low_level_boost pointer if it's NULL or not. > - cpufreq_driver->low_level_boost(): to set desired boost state > (Only for hardware boosting) It has two purposes (as described above) and can be used (defined) by software and hardware boost solutions. > - boost_enabled: global variable in cpufreq.c file, used only if > cpufreq_driver->boost_supported is true. I think that boost enabled flag shall be defined at cpufreq driver (please look into acpi_cpufreq.c - which used another set of global flags). It will then provide one flag for cpufreq.c (core) and drivers. However I've added one global flag: cpufreq_boost_sysfs_defined which indicates if /sys/devices/system/cpu/cpufreq/boost attribute has been already defined (to prevent multiple definitions attempts). > > > > diff --git a/drivers/cpufreq/freq_table.c > > b/drivers/cpufreq/freq_table.c index d7a7966..4e4f692 100644 > > --- a/drivers/cpufreq/freq_table.c > > +++ b/drivers/cpufreq/freq_table.c > > @@ -20,6 +20,27 @@ > > * FREQUENCY TABLE > > HELPERS * > > *********************************************************************/ > > > > +unsigned int > > +cpufreq_frequency_table_max(struct cpufreq_frequency_table > > *freq_table, > > + int boost) > > +{ > > + int i = 0, boost_freq_max = 0, freq_max = 0; > > + > > + for (; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) { > > + if (freq_table[i].index == CPUFREQ_BOOST_FREQ) { > > + if (freq_table[i].frequency > > > boost_freq_max) > > + boost_freq_max = > > freq_table[i].frequency; > > Do above only when boost==true and below when boost==false. Ok. > > > + } else { > > + if (freq_table[i].frequency > freq_max) > > + freq_max = freq_table[i].frequency; > > + } > > + } > > + > > + return boost ? boost_freq_max : freq_max; > > + > > +} > > +EXPORT_SYMBOL_GPL(cpufreq_frequency_table_max); > > + > > int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy, > > struct cpufreq_frequency_table > > *table) { > > @@ -171,7 +192,8 @@ static DEFINE_PER_CPU(struct > > cpufreq_frequency_table *, cpufreq_show_table); /** > > * show_available_freqs - show available frequencies for the > > specified CPU */ > > -static ssize_t show_available_freqs(struct cpufreq_policy *policy, > > char *buf) +static ssize_t show_available_freqs(struct > > cpufreq_policy *policy, char *buf, > > + int show_boost) > > { > > unsigned int i = 0; > > unsigned int cpu = policy->cpu; > > @@ -186,22 +208,53 @@ static ssize_t show_available_freqs(struct > > cpufreq_policy *policy, char *buf) for (i = 0; > > (table[i].frequency != CPUFREQ_TABLE_END); i++) { if > > (table[i].frequency == CPUFREQ_ENTRY_INVALID) continue; > > + if (show_boost) > > + if (table[i].index != CPUFREQ_BOOST_FREQ) > > + continue; > > + > > Looks wrong. You will show boost freqs when show_boost is false. My purpose here is to display frequencies only tagged with CPUFREQ_BOOST_FREQ and when show_boost is true. When show_boost is false, the operation of the function is unchanged. > > > count += sprintf(&buf[count], "%d ", > > table[i].frequency); } > > count += sprintf(&buf[count], "\n"); > > > > return count; > > +} > > > > +/** > > + * show_available_normal_freqs - show normal boost frequencies for > > + * the specified CPU > > + */ > > +static ssize_t show_available_normal_freqs(struct cpufreq_policy > > *policy, > > + char *buf) > > +{ > > + return show_available_freqs(policy, buf, 0); > > } > > > > struct freq_attr cpufreq_freq_attr_scaling_available_freqs = { > > .attr = { .name = "scaling_available_frequencies", > > .mode = 0444, > > }, > > - .show = show_available_freqs, > > + .show = show_available_normal_freqs, > > }; > > EXPORT_SYMBOL_GPL(cpufreq_freq_attr_scaling_available_freqs); > > > > +/** > > + * show_available_boost_freqs - show available boost frequencies > > for > > + * the specified CPU > > + */ > > +static ssize_t show_available_boost_freqs(struct cpufreq_policy > > *policy, > > + char *buf) > > +{ > > + return show_available_freqs(policy, buf, 1); > > +} > > + > > +struct freq_attr cpufreq_freq_attr_boost_available_freqs = { > > + .attr = { .name = "scaling_boost_frequencies", > > + .mode = 0444, > > + }, > > + .show = show_available_boost_freqs, > > +}; > > +EXPORT_SYMBOL_GPL(cpufreq_freq_attr_boost_available_freqs); > > + > > Code redundancy can be reduced by creating a macro for declaring > **_availabe_freqs, its attributes and export symbol. Yes, you are right here. Those two structures only differ with different names. > > > /* > > * if you use these, you must assure that the frequency table is > > valid > > * all the time between get_attr and put_attr! > > With this patch alone, we would be using boost frequencies even in > normal cases where we haven't enabled boost. Correct me if I'm wrong here, but the cpufreq_freq_attr_boost_available_freqs will be added to cpufreq driver's freq_attr table (i.e. *exynos_cpufreq_attr[]). It is cpufreq driver's responsibility to add this attribute. By default all other drivers add only cpufreq_freq_attr_boost_available_freqs. -- Best regards, Lukasz Majewski Samsung R&D Institute Poland (SRPOL) | Linux Platform Group