Commit 06ee47aa authored by LeoLiu-oc's avatar LeoLiu-oc
Browse files

cpufreq: ACPI: add ITMT support when CPPC enabled 

zhaoxin inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBB6OU


CVE: NA

-------------------

The _CPC method can get per-core highest frequency.
The highest frequency may varies between cores which mean cores can
running at different max frequency, so can use it as a core priority
and give a hint to scheduler in order to put critical task to the
higher priority core.

Fixes: a5456c60 ("cpufreq: ACPI: add ITMT support when CPPC enabled").
Signed-off-by: default avatarLeoLiu-oc <leoliu-oc@zhaoxin.com>
parent 3ce195bf

arch/x86/kernel/itmt.c

+2 −0
Original line number Diff line number Diff line
@@ -122,6 +122,7 @@ int sched_set_itmt_support(void) 


	return 0;

}

EXPORT_SYMBOL(sched_set_itmt_support);



/**

 * sched_clear_itmt_support() - Revoke platform's support of ITMT
@@ -181,3 +182,4 @@ void sched_set_itmt_core_prio(int prio, int cpu) 
{

	per_cpu(sched_core_priority, cpu) = prio;

}

EXPORT_SYMBOL(sched_set_itmt_core_prio);

drivers/cpufreq/acpi-cpufreq.c

+60 −1
Original line number Diff line number Diff line
@@ -627,6 +627,19 @@ static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c) 
}

#endif



/* The work item is needed to avoid CPU hotplug locking issues */

static void sched_itmt_work_fn(struct work_struct *work)

{

	sched_set_itmt_support();

}



static DECLARE_WORK(sched_itmt_work, sched_itmt_work_fn);



static void sched_set_itmt(void)

{

	schedule_work(&sched_itmt_work);

}



#ifdef CONFIG_ACPI_CPPC_LIB

static u64 get_max_boost_ratio(unsigned int cpu)

{
@@ -663,8 +676,49 @@ static u64 get_max_boost_ratio(unsigned int cpu) 


	return div_u64(highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);

}



static bool cppc_highest_perf_diff;

static struct cpumask core_prio_cpumask;



static void core_set_itmt_prio(int cpu)

{

	u64 highest_perf = 0;

	int ret = 0;

	static u64 max_highest_perf = 0, min_highest_perf = U64_MAX;



	ret = cppc_get_highest_perf(cpu, &highest_perf);

	if (ret) {

		pr_debug("CPU%d: Unable to get performance capabilities (%d)\n", cpu, ret);

		return;

	}

	sched_set_itmt_core_prio(highest_perf, cpu);

	cpumask_set_cpu(cpu, &core_prio_cpumask);



	if (max_highest_perf <= min_highest_perf) {

		if (highest_perf > max_highest_perf)

			max_highest_perf = highest_perf;



		if (highest_perf < min_highest_perf)

			min_highest_perf = highest_perf;



		if (max_highest_perf > min_highest_perf)

			cppc_highest_perf_diff = true;

	}



	if (cppc_highest_perf_diff && cpumask_equal(&core_prio_cpumask, cpu_online_mask)) {

		/*

		 * This code  can be run during CPU online under the CPU hotplug locks,

		 * so sched_set_itmt cannot be called from here.

		 * queue a work item to invoke it

		 */

		pr_debug("queue a work to set itmt support and enable\n");

		sched_set_itmt();

	}

}



#else

static inline u64 get_max_boost_ratio(unsigned int cpu) { return 0; }

static void core_set_itmt_prio(int cpu) {}

#endif



static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
@@ -677,7 +731,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) 
	unsigned int valid_states = 0;

	unsigned int result = 0;

	u64 max_boost_ratio;

	unsigned int i;

	unsigned int i, j = 0;

#ifdef CONFIG_SMP

	static int blacklisted;

#endif
@@ -742,6 +796,11 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) 
	}

#endif



	if (c->x86_vendor == X86_VENDOR_CENTAUR || c->x86_vendor == X86_VENDOR_ZHAOXIN) {

		for_each_cpu(j, policy->cpus)

			core_set_itmt_prio(j);

	}



	/* capability check */

	if (perf->state_count <= 1) {

		pr_debug("No P-States\n");