Commit 5214b563 authored by Suzuki K Poulose's avatar Suzuki K Poulose Committed by Greg Kroah-Hartman
Browse files

coresight: etm4x: Add support for sysreg only devices 

Add support for devices with system instruction access only.
They don't have a memory mapped interface and thus are not
AMBA devices. System register access is not permitted to
TRCPDCR and thus skip access to them.

Link: https://lore.kernel.org/r/20210110224850.1880240-26-suzuki.poulose@arm.com


Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-28-mathieu.poirier@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e97db2cf

drivers/hwtracing/coresight/coresight-etm4x-core.c

+63 −5
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/seq_file.h>

#include <linux/uaccess.h>

#include <linux/perf_event.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/property.h>
@@ -1736,9 +1737,6 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid) 
			return -ENOMEM;

	}



	if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))

		drvdata->skip_power_up = true;



	drvdata->base = base;



	spin_lock_init(&drvdata->spinlock);
@@ -1762,6 +1760,11 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid) 
	if (!drvdata->arch)

		return -EINVAL;



	/* TRCPDCR is not accessible with system instructions. */

	if (!desc.access.io_mem ||

	    fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))

		drvdata->skip_power_up = true;



	etm4_init_trace_id(drvdata);

	etm4_set_default(&drvdata->config);
@@ -1820,6 +1823,25 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id) 
	return ret;

}



static int etm4_probe_platform_dev(struct platform_device *pdev)

{

	int ret;



	pm_runtime_get_noresume(&pdev->dev);

	pm_runtime_set_active(&pdev->dev);

	pm_runtime_enable(&pdev->dev);



	/*

	 * System register based devices could match the

	 * HW by reading appropriate registers on the HW

	 * and thus we could skip the PID.

	 */

	ret = etm4_probe(&pdev->dev, NULL, 0);



	pm_runtime_put(&pdev->dev);

	return ret;

}



static struct amba_cs_uci_id uci_id_etm4[] = {

	{

		/*  ETMv4 UCI data */
@@ -1869,6 +1891,17 @@ static int __exit etm4_remove_amba(struct amba_device *adev) 
	return 0;

}



static int __exit etm4_remove_platform_dev(struct platform_device *pdev)

{

	int ret = 0;

	struct etmv4_drvdata *drvdata = dev_get_drvdata(&pdev->dev);



	if (drvdata)

		ret = etm4_remove_dev(drvdata);

	pm_runtime_disable(&pdev->dev);

	return ret;

}



static const struct amba_id etm4_ids[] = {

	CS_AMBA_ID(0x000bb95d),			/* Cortex-A53 */

	CS_AMBA_ID(0x000bb95e),			/* Cortex-A57 */
@@ -1903,6 +1936,21 @@ static struct amba_driver etm4x_amba_driver = { 
	.id_table	= etm4_ids,

};



static const struct of_device_id etm4_sysreg_match[] = {

	{ .compatible	= "arm,coresight-etm4x-sysreg" },

	{}

};



static struct platform_driver etm4_platform_driver = {

	.probe		= etm4_probe_platform_dev,

	.remove		= etm4_remove_platform_dev,

	.driver			= {

		.name			= "coresight-etm4x",

		.of_match_table		= etm4_sysreg_match,

		.suppress_bind_attrs	= true,

	},

};



static int __init etm4x_init(void)

{

	int ret;
@@ -1915,16 +1963,26 @@ static int __init etm4x_init(void) 


	ret = amba_driver_register(&etm4x_amba_driver);

	if (ret) {

		pr_err("Error registering etm4x driver\n");

		etm4_pm_clear();

		pr_err("Error registering etm4x AMBA driver\n");

		goto clear_pm;

	}



	ret = platform_driver_register(&etm4_platform_driver);

	if (!ret)

		return 0;



	pr_err("Error registering etm4x platform driver\n");

	amba_driver_unregister(&etm4x_amba_driver);



clear_pm:

	etm4_pm_clear();

	return ret;

}



static void __exit etm4x_exit(void)

{

	amba_driver_unregister(&etm4x_amba_driver);

	platform_driver_unregister(&etm4_platform_driver);

	etm4_pm_clear();

}