cpufreq: amd-pstate: Add boost mode support for AMD P-State

If the sbios supports the boost mode of AMD P-State, let's switch to
boost enabled by default.

Signed-off-by: Huang Rui <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/cpufreq/amd-pstate.c

···
 struct amd_cpudata {
 	int	cpu;
 
+	struct	freq_qos_request req[2];
 	u64	cppc_req_cached;
 
 	u32	highest_perf;
···
 	u32	min_freq;
 	u32	nominal_freq;
 	u32	lowest_nonlinear_freq;
+
+	bool	boost_supported;
 };
 
 static inline int pstate_enable(bool enable)
···
 	return lowest_nonlinear_freq * 1000;
 }
 
+static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
+{
+	struct amd_cpudata *cpudata = policy->driver_data;
+	int ret;
+
+	if (!cpudata->boost_supported) {
+		pr_err("Boost mode is not supported by this processor or SBIOS\n");
+		return -EINVAL;
+	}
+
+	if (state)
+		policy->cpuinfo.max_freq = cpudata->max_freq;
+	else
+		policy->cpuinfo.max_freq = cpudata->nominal_freq;
+
+	policy->max = policy->cpuinfo.max_freq;
+
+	ret = freq_qos_update_request(&cpudata->req[1],
+				      policy->cpuinfo.max_freq);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
+{
+	u32 highest_perf, nominal_perf;
+
+	highest_perf = READ_ONCE(cpudata->highest_perf);
+	nominal_perf = READ_ONCE(cpudata->nominal_perf);
+
+	if (highest_perf <= nominal_perf)
+		return;
+
+	cpudata->boost_supported = true;
+	amd_pstate_driver.boost_enabled = true;
+}
+
 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 {
 	int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
···
 
 	ret = amd_pstate_init_perf(cpudata);
 	if (ret)
-		goto free_cpudata;
+		goto free_cpudata1;
 
 	min_freq = amd_get_min_freq(cpudata);
 	max_freq = amd_get_max_freq(cpudata);
···
 		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
 			min_freq, max_freq);
 		ret = -EINVAL;
-		goto free_cpudata;
+		goto free_cpudata1;
 	}
 
 	policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY;
···
 	if (boot_cpu_has(X86_FEATURE_CPPC))
 		policy->fast_switch_possible = true;
 
+	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[0],
+				   FREQ_QOS_MIN, policy->cpuinfo.min_freq);
+	if (ret < 0) {
+		dev_err(dev, "Failed to add min-freq constraint (%d)\n", ret);
+		goto free_cpudata1;
+	}
+
+	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[1],
+				   FREQ_QOS_MAX, policy->cpuinfo.max_freq);
+	if (ret < 0) {
+		dev_err(dev, "Failed to add max-freq constraint (%d)\n", ret);
+		goto free_cpudata2;
+	}
+
 	/* Initial processor data capability frequencies */
 	cpudata->max_freq = max_freq;
 	cpudata->min_freq = min_freq;
···
 
 	policy->driver_data = cpudata;
 
+	amd_pstate_boost_init(cpudata);
+
 	return 0;
 
-free_cpudata:
+free_cpudata2:
+	freq_qos_remove_request(&cpudata->req[0]);
+free_cpudata1:
 	kfree(cpudata);
 	return ret;
 }
···
 
 	cpudata = policy->driver_data;
 
+	freq_qos_remove_request(&cpudata->req[1]);
+	freq_qos_remove_request(&cpudata->req[0]);
 	kfree(cpudata);
 
 	return 0;
···
 	.target		= amd_pstate_target,
 	.init		= amd_pstate_cpu_init,
 	.exit		= amd_pstate_cpu_exit,
+	.set_boost	= amd_pstate_set_boost,
 	.name		= "amd-pstate",
 };