cpufreq: move freq change notifications to cpufreq core

Most of the drivers do following in their ->target_index() routines:

	struct cpufreq_freqs freqs;
	freqs.old = old freq...
	freqs.new = new freq...

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	/* Change rate here */

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

This is replicated over all cpufreq drivers today and there doesn't exists a
good enough reason why this shouldn't be moved to cpufreq core instead.

There are few special cases though, like exynos5440, which doesn't do everything
on the call to ->target_index() routine and call some kind of bottom halves for
doing this work, work/tasklet/etc..

They may continue doing notification from their own code as flag:
CPUFREQ_ASYNC_NOTIFICATION is already set for them.

All drivers are also modified in this patch to avoid breaking 'git bisect', as
double notification would happen otherwise.

Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/acpi-cpufreq.c

@@ -428,14 +428,10 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 {
 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
 	struct acpi_processor_performance *perf;
-	struct cpufreq_freqs freqs;
 	struct drv_cmd cmd;
 	unsigned int next_perf_state = 0; /* Index into perf table */
 	int result = 0;
 
-	pr_debug("acpi_cpufreq_target %d (%d)\n",
-			data->freq_table[index].frequency, policy->cpu);
-
 	if (unlikely(data == NULL ||
 	     data->acpi_data == NULL || data->freq_table == NULL)) {
 		return -ENODEV;
@@ -483,23 +479,17 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy,
 	else
 		cmd.mask = cpumask_of(policy->cpu);
 
-	freqs.old = perf->states[perf->state].core_frequency * 1000;
-	freqs.new = data->freq_table[index].frequency;
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-
 	drv_write(&cmd);
 
 	if (acpi_pstate_strict) {
-		if (!check_freqs(cmd.mask, freqs.new, data)) {
+		if (!check_freqs(cmd.mask, data->freq_table[index].frequency,
+					data)) {
 			pr_debug("acpi_cpufreq_target failed (%d)\n",
 				policy->cpu);
 			result = -EAGAIN;
-			freqs.new = freqs.old;
 		}
 	}
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
 	if (!result)
 		perf->state = next_perf_state;
 

drivers/cpufreq/arm_big_little.c

@@ -192,39 +192,25 @@ bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
 static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
 		unsigned int index)
 {
-	struct cpufreq_freqs freqs;
 	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
-	int ret = 0;
+	unsigned int freqs_new;
 
 	cur_cluster = cpu_to_cluster(cpu);
 	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
 
-	freqs.old = bL_cpufreq_get_rate(cpu);
-	freqs.new = freq_table[cur_cluster][index].frequency;
-
-	pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
-			__func__, cpu, cur_cluster, freqs.old, freqs.new,
-			freqs.new);
+	freqs_new = freq_table[cur_cluster][index].frequency;
 
 	if (is_bL_switching_enabled()) {
 		if ((actual_cluster == A15_CLUSTER) &&
-				(freqs.new < clk_big_min)) {
+				(freqs_new < clk_big_min)) {
 			new_cluster = A7_CLUSTER;
 		} else if ((actual_cluster == A7_CLUSTER) &&
-				(freqs.new > clk_little_max)) {
+				(freqs_new > clk_little_max)) {
 			new_cluster = A15_CLUSTER;
 		}
 	}
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-
-	ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs.new);
-	if (ret)
-		freqs.new = freqs.old;
-
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
-	return ret;
+	return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
 }
 
 static inline u32 get_table_count(struct cpufreq_frequency_table *table)

drivers/cpufreq/at32ap-cpufreq.c

@@ -37,27 +37,23 @@ static unsigned long	loops_per_jiffy_ref;
 
 static int at32_set_target(struct cpufreq_policy *policy, unsigned int index)
 {
-	struct cpufreq_freqs freqs;
+	unsigned int old_freq, new_freq;
 
-	freqs.old = at32_get_speed(0);
-	freqs.new = freq_table[index].frequency;
+	old_freq = at32_get_speed(0);
+	new_freq = freq_table[index].frequency;
 
 	if (!ref_freq) {
-		ref_freq = freqs.old;
+		ref_freq = old_freq;
 		loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy;
 	}
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-	if (freqs.old < freqs.new)
+	if (old_freq < new_freq)
 		boot_cpu_data.loops_per_jiffy = cpufreq_scale(
-				loops_per_jiffy_ref, ref_freq, freqs.new);
-	clk_set_rate(cpuclk, freqs.new * 1000);
-	if (freqs.new < freqs.old)
+				loops_per_jiffy_ref, ref_freq, new_freq);
+	clk_set_rate(cpuclk, new_freq * 1000);
+	if (new_freq < old_freq)
 		boot_cpu_data.loops_per_jiffy = cpufreq_scale(
-				loops_per_jiffy_ref, ref_freq, freqs.new);
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
-	pr_debug("cpufreq: set frequency %u Hz\n", freqs.new * 1000);
+				loops_per_jiffy_ref, ref_freq, new_freq);
 
 	return 0;
 }

drivers/cpufreq/blackfin-cpufreq.c

@@ -132,27 +132,23 @@ static int bfin_target(struct cpufreq_policy *policy, unsigned int index)
 #ifndef CONFIG_BF60x
 	unsigned int plldiv;
 #endif
-	struct cpufreq_freqs freqs;
 	static unsigned long lpj_ref;
 	static unsigned int  lpj_ref_freq;
+	unsigned int old_freq, new_freq;
 	int ret = 0;
 
 #if defined(CONFIG_CYCLES_CLOCKSOURCE)
 	cycles_t cycles;
 #endif
 
-	freqs.old = bfin_getfreq_khz(0);
-	freqs.new = bfin_freq_table[index].frequency;
+	old_freq = bfin_getfreq_khz(0);
+	new_freq = bfin_freq_table[index].frequency;
 
-	pr_debug("cpufreq: changing cclk to %lu; target = %u, oldfreq = %u\n",
-			freqs.new, freqs.new, freqs.old);
-
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
 #ifndef CONFIG_BF60x
 	plldiv = (bfin_read_PLL_DIV() & SSEL) | dpm_state_table[index].csel;
 	bfin_write_PLL_DIV(plldiv);
 #else
-	ret = cpu_set_cclk(policy->cpu, freqs.new * 1000);
+	ret = cpu_set_cclk(policy->cpu, new_freq * 1000);
 	if (ret != 0) {
 		WARN_ONCE(ret, "cpufreq set freq failed %d\n", ret);
 		return ret;
@@ -168,17 +164,13 @@ static int bfin_target(struct cpufreq_policy *policy, unsigned int index)
 #endif
 	if (!lpj_ref_freq) {
 		lpj_ref = loops_per_jiffy;
-		lpj_ref_freq = freqs.old;
+		lpj_ref_freq = old_freq;
 	}
-	if (freqs.new != freqs.old) {
+	if (new_freq != old_freq) {
 		loops_per_jiffy = cpufreq_scale(lpj_ref,
-				lpj_ref_freq, freqs.new);
+				lpj_ref_freq, new_freq);
 	}
 
-	/* TODO: just test case for cycles clock source, remove later */
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
-	pr_debug("cpufreq: done\n");
 	return ret;
 }
 

drivers/cpufreq/cpufreq-cpu0.c

@@ -37,30 +37,27 @@ static unsigned int cpu0_get_speed(unsigned int cpu)
 
 static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
 {
-	struct cpufreq_freqs freqs;
 	struct dev_pm_opp *opp;
 	unsigned long volt = 0, volt_old = 0, tol = 0;
+	unsigned int old_freq, new_freq;
 	long freq_Hz, freq_exact;
 	int ret;
 
 	freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
 	if (freq_Hz < 0)
 		freq_Hz = freq_table[index].frequency * 1000;
-	freq_exact = freq_Hz;
-	freqs.new = freq_Hz / 1000;
-	freqs.old = clk_get_rate(cpu_clk) / 1000;
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
+	freq_exact = freq_Hz;
+	new_freq = freq_Hz / 1000;
+	old_freq = clk_get_rate(cpu_clk) / 1000;
 
 	if (!IS_ERR(cpu_reg)) {
 		rcu_read_lock();
 		opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz);
 		if (IS_ERR(opp)) {
 			rcu_read_unlock();
 			pr_err("failed to find OPP for %ld\n", freq_Hz);
-			freqs.new = freqs.old;
-			ret = PTR_ERR(opp);
-			goto post_notify;
+			return PTR_ERR(opp);
 		}
 		volt = dev_pm_opp_get_voltage(opp);
 		rcu_read_unlock();
@@ -69,16 +66,15 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
 	}
 
 	pr_debug("%u MHz, %ld mV --> %u MHz, %ld mV\n",
-		 freqs.old / 1000, volt_old ? volt_old / 1000 : -1,
-		 freqs.new / 1000, volt ? volt / 1000 : -1);
+		 old_freq / 1000, volt_old ? volt_old / 1000 : -1,
+		 new_freq / 1000, volt ? volt / 1000 : -1);
 
 	/* scaling up?  scale voltage before frequency */
-	if (!IS_ERR(cpu_reg) && freqs.new > freqs.old) {
+	if (!IS_ERR(cpu_reg) && new_freq > old_freq) {
 		ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
 		if (ret) {
 			pr_err("failed to scale voltage up: %d\n", ret);
-			freqs.new = freqs.old;
-			goto post_notify;
+			return ret;
 		}
 	}
 
@@ -87,23 +83,18 @@ static int cpu0_set_target(struct cpufreq_policy *policy, unsigned int index)
 		pr_err("failed to set clock rate: %d\n", ret);
 		if (!IS_ERR(cpu_reg))
 			regulator_set_voltage_tol(cpu_reg, volt_old, tol);
-		freqs.new = freqs.old;
-		goto post_notify;
+		return ret;
 	}
 
 	/* scaling down?  scale voltage after frequency */
-	if (!IS_ERR(cpu_reg) && freqs.new < freqs.old) {
+	if (!IS_ERR(cpu_reg) && new_freq < old_freq) {
 		ret = regulator_set_voltage_tol(cpu_reg, volt, tol);
 		if (ret) {
 			pr_err("failed to scale voltage down: %d\n", ret);
-			clk_set_rate(cpu_clk, freqs.old * 1000);
-			freqs.new = freqs.old;
+			clk_set_rate(cpu_clk, old_freq * 1000);
 		}
 	}
 
-post_notify:
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
 	return ret;
 }
 

drivers/cpufreq/cpufreq.c

@@ -1669,6 +1669,8 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 		retval = cpufreq_driver->target(policy, target_freq, relation);
 	else if (cpufreq_driver->target_index) {
 		struct cpufreq_frequency_table *freq_table;
+		struct cpufreq_freqs freqs;
+		bool notify;
 		int index;
 
 		freq_table = cpufreq_frequency_get_table(policy->cpu);
@@ -1684,10 +1686,42 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy,
 			goto out;
 		}
 
-		if (freq_table[index].frequency == policy->cur)
+		if (freq_table[index].frequency == policy->cur) {
 			retval = 0;
-		else
-			retval = cpufreq_driver->target_index(policy, index);
+			goto out;
+		}
+
+		notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION);
+
+		if (notify) {
+			freqs.old = policy->cur;
+			freqs.new = freq_table[index].frequency;
+			freqs.flags = 0;
+
+			pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n",
+					__func__, policy->cpu, freqs.old,
+					freqs.new);
+
+			cpufreq_notify_transition(policy, &freqs,
+					CPUFREQ_PRECHANGE);
+		}
+
+		retval = cpufreq_driver->target_index(policy, index);
+		if (retval)
+			pr_err("%s: Failed to change cpu frequency: %d\n",
+					__func__, retval);
+
+		if (notify) {
+			/*
+			 * Notify with old freq in case we failed to change
+			 * frequency
+			 */
+			if (retval)
+				freqs.new = freqs.old;
+
+			cpufreq_notify_transition(policy, &freqs,
+					CPUFREQ_POSTCHANGE);
+		}
 	}
 
 out:

drivers/cpufreq/cris-artpec3-cpufreq.c

@@ -29,15 +29,9 @@ static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
 
 static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
 {
-	struct cpufreq_freqs freqs;
 	reg_clkgen_rw_clk_ctrl clk_ctrl;
 	clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
 
-	freqs.old = cris_freq_get_cpu_frequency(policy->cpu);
-	freqs.new = cris_freq_table[state].frequency;
-
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-
 	local_irq_disable();
 
 	/* Even though we may be SMP they will share the same clock
@@ -50,8 +44,6 @@ static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
 
 	local_irq_enable();
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
 	return 0;
 }
 

drivers/cpufreq/cris-etraxfs-cpufreq.c

@@ -29,15 +29,9 @@ static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
 
 static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
 {
-	struct cpufreq_freqs freqs;
 	reg_config_rw_clk_ctrl clk_ctrl;
 	clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl);
 
-	freqs.old = cris_freq_get_cpu_frequency(policy->cpu);
-	freqs.new = cris_freq_table[state].frequency;
-
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
-
 	local_irq_disable();
 
 	/* Even though we may be SMP they will share the same clock
@@ -50,8 +44,6 @@ static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
 
 	local_irq_enable();
 
-	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
-
 	return 0;
 }