[PATCH 05/14] cpufreq: intel_pstate: Clean up intel_pstate_busy_pid_reset()

From: Rafael J. Wysocki
Date: Sun Mar 12 2017 - 13:32:55 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

intel_pstate_busy_pid_reset() is the only caller of pid_reset(),
pid_p_gain_set(), pid_i_gain_set(), and pid_d_gain_set(). Moreover,
it passes constatns as two parameters of pid_reset() and all of
the other routines above essentially contain the same code, so
fold all of them into the caller and drop unnecessary computations.

Introduce percent_fp() for converting integer values in percent
to fixed-point fractions and use it in the above code cleanup.

Finally, rename intel_pstate_busy_pid_reset() to
intel_pstate_pid_reset() as it also is used for the
initialization of PID parameters for every CPU and the
meaning of the "busy" part of the name is not particularly
clear.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/cpufreq/intel_pstate.c | 46 ++++++++++++++---------------------------
1 file changed, 16 insertions(+), 30 deletions(-)

Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -79,6 +79,11 @@ static inline int ceiling_fp(int32_t x)
return ret;
}

+static inline int32_t percent_fp(int percent)
+{
+ return div_fp(percent, 100);
+}
+
static inline u64 mul_ext_fp(u64 x, u64 y)
{
return (x * y) >> EXT_FRAC_BITS;
@@ -547,29 +552,6 @@ static inline void intel_pstate_exit_per
}
#endif

-static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
- int deadband, int integral) {
- pid->setpoint = int_tofp(setpoint);
- pid->deadband = int_tofp(deadband);
- pid->integral = int_tofp(integral);
- pid->last_err = int_tofp(setpoint) - int_tofp(busy);
-}
-
-static inline void pid_p_gain_set(struct _pid *pid, int percent)
-{
- pid->p_gain = div_fp(percent, 100);
-}
-
-static inline void pid_i_gain_set(struct _pid *pid, int percent)
-{
- pid->i_gain = div_fp(percent, 100);
-}
-
-static inline void pid_d_gain_set(struct _pid *pid, int percent)
-{
- pid->d_gain = div_fp(percent, 100);
-}
-
static signed int pid_calc(struct _pid *pid, int32_t busy)
{
signed int result;
@@ -607,13 +589,17 @@ static signed int pid_calc(struct _pid *
return (signed int)fp_toint(result);
}

-static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
+static inline void intel_pstate_pid_reset(struct cpudata *cpu)
{
- pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
- pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
- pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
+ struct _pid *pid = &cpu->pid;

- pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.deadband, 0);
+ pid->p_gain = percent_fp(pid_params.p_gain_pct);
+ pid->d_gain = percent_fp(pid_params.d_gain_pct);
+ pid->i_gain = percent_fp(pid_params.i_gain_pct);
+ pid->setpoint = int_tofp(pid_params.setpoint);
+ pid->last_err = pid->setpoint - int_tofp(100);
+ pid->deadband = int_tofp(pid_params.deadband);
+ pid->integral = 0;
}

static inline void update_turbo_state(void)
@@ -985,7 +971,7 @@ static int pid_param_set(void *data, u64
pid_params.sample_rate_ns = pid_params.sample_rate_ms * NSEC_PER_MSEC;
for_each_possible_cpu(cpu)
if (all_cpu_data[cpu])
- intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
+ intel_pstate_pid_reset(all_cpu_data[cpu]);

return 0;
}
@@ -1994,7 +1980,7 @@ static int intel_pstate_init_cpu(unsigne

intel_pstate_get_cpu_pstates(cpu);

- intel_pstate_busy_pid_reset(cpu);
+ intel_pstate_pid_reset(cpu);

pr_debug("controlling: cpu %d\n", cpunum);