Re: [PATCH v2 6/6] powernv:cpufreq: Implement the driver-get() method

2014-03-17 Thread Preeti U Murthy 
On 03/10/2014 04:41 PM, Gautham R. Shenoy wrote:
 From: Gautham R. Shenoy e...@linux.vnet.ibm.com
 
 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 e...@linux.vnet.ibm.com
 ---
  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 pre...@linux.vnet.ibm.com

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[PATCH v2 6/6] powernv:cpufreq: Implement the driver-get() method

2014-03-10 Thread Gautham R. Shenoy 
From: Gautham R. Shenoy e...@linux.vnet.ibm.com

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 e...@linux.vnet.ibm.com
---
 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,
-- 
1.8.3.1

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