From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 32B592C0098 for ; Mon, 17 Mar 2014 20:15:07 +1100 (EST) Received: from /spool/local by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 17 Mar 2014 03:15:05 -0600 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id BFF4319D8036 for ; Mon, 17 Mar 2014 03:14:59 -0600 (MDT) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by b03cxnp08026.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s2H9EUuZ9699752 for ; Mon, 17 Mar 2014 10:14:30 +0100 Received: from d03av05.boulder.ibm.com (localhost [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s2H9F2SF005218 for ; Mon, 17 Mar 2014 03:15:02 -0600 Message-ID: <5326BC2E.7060503@linux.vnet.ibm.com> Date: Mon, 17 Mar 2014 14:41:10 +0530 From: Preeti U Murthy MIME-Version: 1.0 To: "Gautham R. Shenoy" Subject: Re: [PATCH v2 6/6] powernv:cpufreq: Implement the driver->get() method References: <1394449861-8688-1-git-send-email-ego@linux.vnet.ibm.com> <1394449861-8688-7-git-send-email-ego@linux.vnet.ibm.com> In-Reply-To: <1394449861-8688-7-git-send-email-ego@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Cc: linuxppc-dev@ozlabs.org, srivatsa.bhat@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 03/10/2014 04:41 PM, Gautham R. Shenoy wrote: > 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 | 48 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 48 insertions(+) > > diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c > index 183bbc4..6f3b6e1 100644 > --- a/drivers/cpufreq/powernv-cpufreq.c > +++ b/drivers/cpufreq/powernv-cpufreq.c > @@ -223,6 +223,53 @@ 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; > + cpumask_var_t sibling_mask; > + > + if (unlikely(!zalloc_cpumask_var(&sibling_mask, GFP_KERNEL))) { > + smp_call_function_single(cpu, powernv_read_cpu_freq, > + &ret_freq, 1); > + return ret_freq; > + } > + > + powernv_cpu_to_core_mask(cpu, sibling_mask); > + smp_call_function_any(sibling_mask, powernv_read_cpu_freq, > + &ret_freq, 1); > + > + free_cpumask_var(sibling_mask); > + return ret_freq; > +} > + > static void set_pstate(void *pstate) > { > unsigned long val; > @@ -309,6 +356,7 @@ 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", > Reviewed-by: Preeti U Murthy