coresight: cti: Add CPU idle pm notifer to CTI devices (6a0953ce) · Commits · 戴 / test

drivers/hwtracing/coresight/coresight-cti.c

+69 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@
		#include <linux/atomic.h>
		#include <linux/bits.h>
		#include <linux/coresight.h>
		#include <linux/cpu_pm.h>
		#include <linux/cpuhotplug.h>
		#include <linux/device.h>
		#include <linux/io.h>
		@@ -656,6 +657,70 @@ static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata)
		}
		}

		/ cti PM callbacks /
		static int cti_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,
		void *v)
		{
		struct cti_drvdata *drvdata;
		unsigned int cpu = smp_processor_id();
		int notify_res = NOTIFY_OK;

		if (!cti_cpu_drvdata[cpu])
		return NOTIFY_OK;

		drvdata = cti_cpu_drvdata[cpu];

		if (WARN_ON_ONCE(drvdata->ctidev.cpu != cpu))
		return NOTIFY_BAD;

		spin_lock(&drvdata->spinlock);

		switch (cmd) {
		case CPU_PM_ENTER:
		/* CTI regs all static - we have a copy & nothing to save */
		drvdata->config.hw_powered = false;
		if (drvdata->config.hw_enabled)
		coresight_disclaim_device(drvdata->base);
		break;

		case CPU_PM_ENTER_FAILED:
		drvdata->config.hw_powered = true;
		if (drvdata->config.hw_enabled) {
		if (coresight_claim_device(drvdata->base))
		drvdata->config.hw_enabled = false;
		}
		break;

		case CPU_PM_EXIT:
		/* write hardware registers to re-enable. */
		drvdata->config.hw_powered = true;
		drvdata->config.hw_enabled = false;

		/* check enable reference count to enable HW */
		if (atomic_read(&drvdata->config.enable_req_count)) {
		/* check we can claim the device as we re-power */
		if (coresight_claim_device(drvdata->base))
		goto cti_notify_exit;

		drvdata->config.hw_enabled = true;
		cti_write_all_hw_regs(drvdata);
		}
		break;

		default:
		notify_res = NOTIFY_DONE;
		break;
		}

		cti_notify_exit:
		spin_unlock(&drvdata->spinlock);
		return notify_res;
		}

		static struct notifier_block cti_cpu_pm_nb = {
		.notifier_call = cti_cpu_pm_notify,
		};

		/* CPU HP handlers */
		static int cti_starting_cpu(unsigned int cpu)
		{
		@@ -687,6 +752,8 @@ static void cti_pm_release(struct cti_drvdata *drvdata)
		{
		if (drvdata->ctidev.cpu >= 0) {
		if (--nr_cti_cpu == 0) {
		cpu_pm_unregister_notifier(&cti_cpu_pm_nb);

		cpuhp_remove_state_nocalls(
		CPUHP_AP_ARM_CORESIGHT_CTI_STARTING);
		}
		@@ -815,6 +882,8 @@ static int cti_probe(struct amba_device adev, const struct amba_id id)
		"arm/coresight_cti:starting",
		cti_starting_cpu, cti_dying_cpu);

		if (!ret)
		ret = cpu_pm_register_notifier(&cti_cpu_pm_nb);
		cpus_read_unlock();
		if (ret)
		goto err_out;

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