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Violators will be prosecuted; Thu, 20 Mar 2014 22:11:13 +1000 Received: from d23relay05.au.ibm.com (d23relay05.au.ibm.com [9.190.235.152]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 686952CE8047 for ; Thu, 20 Mar 2014 23:11:13 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay05.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s2KBoqLo8585716 for ; Thu, 20 Mar 2014 22:50:52 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s2KCBCXX004168 for ; Thu, 20 Mar 2014 23:11:12 +1100 Received: from sofia.in.ibm.com (sofia.in.ibm.com [9.124.35.168]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id s2KCB2Mt003964; Thu, 20 Mar 2014 23:11:11 +1100 From: "Gautham R. Shenoy" To: linuxppc-dev@ozlabs.org, linux-pm@vger.kernel.org Subject: [PATCH v3 5/5] powernv:cpufreq: Implement the driver->get() method Date: Thu, 20 Mar 2014 17:41:00 +0530 Message-Id: <1395317460-14811-6-git-send-email-ego@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1395317460-14811-1-git-send-email-ego@linux.vnet.ibm.com> References: <1395317460-14811-1-git-send-email-ego@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14032012-9264-0000-0000-000005AD8207 Cc: "Gautham R. Shenoy" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: "Gautham R. Shenoy" The current frequency of a cpu is reported through the sysfs file cpuinfo_cur_freq. This requires the driver to implement a "->get(unsigned int cpu)" method which will return the current operating frequency. Implement a function named powernv_cpufreq_get() which reads the local pstate from the PMSR and returns the corresponding frequency. Set the powernv_cpufreq_driver.get hook to powernv_cpufreq_get(). Signed-off-by: Gautham R. Shenoy --- drivers/cpufreq/powernv-cpufreq.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 46bee8a..ef6ed8c 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -206,6 +206,43 @@ static inline void set_pmspr(unsigned long sprn, unsigned long val) BUG(); } +/* + * Computes the current frequency on this cpu + * and stores the result in *ret_freq. + */ +static void powernv_read_cpu_freq(void *ret_freq) +{ + unsigned long pmspr_val; + s8 local_pstate_id; + int *cur_freq, freq, pstate_id; + + cur_freq = (int *)ret_freq; + pmspr_val = get_pmspr(SPRN_PMSR); + + /* The local pstate id corresponds bits 48..55 in the PMSR. + * Note: Watch out for the sign! */ + local_pstate_id = (pmspr_val >> 48) & 0xFF; + pstate_id = local_pstate_id; + + freq = pstate_id_to_freq(pstate_id); + pr_debug("cpu %d pmsr %lx pstate_id %d frequency %d \n", + smp_processor_id(), pmspr_val, pstate_id, freq); + *cur_freq = freq; +} + +/* + * Returns the cpu frequency as reported by the firmware for 'cpu'. + * This value is reported through the sysfs file cpuinfo_cur_freq. + */ +unsigned int powernv_cpufreq_get(unsigned int cpu) +{ + int ret_freq; + + smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq, + &ret_freq, 1); + return ret_freq; +} + static void set_pstate(void *pstate) { unsigned long val; @@ -297,6 +334,7 @@ static int powernv_cpufreq_target(struct cpufreq_policy *policy, static struct cpufreq_driver powernv_cpufreq_driver = { .verify = powernv_cpufreq_verify, .target = powernv_cpufreq_target, + .get = powernv_cpufreq_get, .init = powernv_cpufreq_cpu_init, .exit = powernv_cpufreq_cpu_exit, .name = "powernv-cpufreq",