coresight: Populate CPU ID into coresight_device

Add a new flag CORESIGHT_DESC_CPU_BOUND to indicate components that
are CPU bound.  Populate CPU ID into the coresight_device structure;
otherwise, set CPU ID to -1 for non CPU bound devices.

Use the {0} initializer to clear coresight_desc structures to avoid
uninitialized values.

Tested-by: Jie Gan <jie.gan@oss.qualcomm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260515-arm_coresight_path_power_management_improvement-v14-4-f88c4a3ecfe9@arm.com

drivers/hwtracing/coresight/coresight-catu.c

@@ -514,7 +514,7 @@ static int __catu_probe(struct device *dev, struct resource *res)
 	int ret = 0;
 	u32 dma_mask;
 	struct catu_drvdata *drvdata;
-	struct coresight_desc catu_desc;
+	struct coresight_desc catu_desc = { 0 };
 	struct coresight_platform_data *pdata = NULL;
 	void __iomem *base;
 

drivers/hwtracing/coresight/coresight-core.c

@@ -1350,6 +1350,19 @@ coresight_init_device(struct coresight_desc *desc)
 	csdev->access = desc->access;
 	csdev->orphan = true;
 
+	if (desc->flags & CORESIGHT_DESC_CPU_BOUND) {
+		csdev->cpu = desc->cpu;
+	} else {
+		/* A per-CPU source or sink must set CPU_BOUND flag */
+		if (coresight_is_percpu_source(csdev) ||
+		    coresight_is_percpu_sink(csdev)) {
+			kfree(csdev);
+			return ERR_PTR(-EINVAL);
+		}
+
+		csdev->cpu = -1;
+	}
+
 	csdev->dev.type = &coresight_dev_type[desc->type];
 	csdev->dev.groups = desc->groups;
 	csdev->dev.parent = desc->dev;

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

@@ -659,7 +659,7 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
 	void __iomem *base;
 	struct device *dev = &adev->dev;
 	struct cti_drvdata *drvdata = NULL;
-	struct coresight_desc cti_desc;
+	struct coresight_desc cti_desc = { 0 };
 	struct coresight_platform_data *pdata = NULL;
 	struct resource *res = &adev->res;
 
@@ -702,11 +702,14 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
 	 * eCPU ID. System CTIs will have the name cti_sys<I> where I is an
 	 * index allocated by order of discovery.
 	 */
-	if (drvdata->ctidev.cpu >= 0)
+	if (drvdata->ctidev.cpu >= 0) {
+		cti_desc.cpu = drvdata->ctidev.cpu;
+		cti_desc.flags = CORESIGHT_DESC_CPU_BOUND;
 		cti_desc.name = devm_kasprintf(dev, GFP_KERNEL, "cti_cpu%d",
 					       drvdata->ctidev.cpu);
-	else
+	} else {
 		cti_desc.name = coresight_alloc_device_name("cti_sys", dev);
+	}
 	if (!cti_desc.name)
 		return -ENOMEM;
 

drivers/hwtracing/coresight/coresight-etm3x-core.c

@@ -891,6 +891,8 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 	desc.pdata = pdata;
 	desc.dev = dev;
 	desc.groups = coresight_etm_groups;
+	desc.cpu = drvdata->cpu;
+	desc.flags = CORESIGHT_DESC_CPU_BOUND;
 	drvdata->csdev = coresight_register(&desc);
 	if (IS_ERR(drvdata->csdev))
 		return PTR_ERR(drvdata->csdev);

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

@@ -2291,6 +2291,8 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
 	desc.pdata = pdata;
 	desc.dev = dev;
 	desc.groups = coresight_etmv4_groups;
+	desc.cpu = drvdata->cpu;
+	desc.flags = CORESIGHT_DESC_CPU_BOUND;
 	drvdata->csdev = coresight_register(&desc);
 	if (IS_ERR(drvdata->csdev))
 		return PTR_ERR(drvdata->csdev);

drivers/hwtracing/coresight/coresight-trbe.c

@@ -1289,6 +1289,8 @@ static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cp
 	desc.ops = &arm_trbe_cs_ops;
 	desc.groups = arm_trbe_groups;
 	desc.dev = dev;
+	desc.cpu = cpu;
+	desc.flags = CORESIGHT_DESC_CPU_BOUND;
 	trbe_csdev = coresight_register(&desc);
 	if (IS_ERR(trbe_csdev))
 		goto cpu_clear;

include/linux/coresight.h

@@ -141,6 +141,8 @@ struct csdev_access {
 		.base		= (_addr),	\
 	})
 
+#define CORESIGHT_DESC_CPU_BOUND	BIT(0)
+
 /**
  * struct coresight_desc - description of a component required from drivers
  * @type:	as defined by @coresight_dev_type.
@@ -153,6 +155,8 @@ struct csdev_access {
  *		in the component's sysfs sub-directory.
  * @name:	name for the coresight device, also shown under sysfs.
  * @access:	Describe access to the device
+ * @flags:	The descritpion flags.
+ * @cpu:	The CPU this component is affined to.
  */
 struct coresight_desc {
 	enum coresight_dev_type type;
@@ -163,6 +167,8 @@ struct coresight_desc {
 	const struct attribute_group **groups;
 	const char *name;
 	struct csdev_access access;
+	u32 flags;
+	int cpu;
 };
 
 /**
@@ -260,6 +266,7 @@ struct coresight_trace_id_map {
  *		device's spinlock when the coresight_mutex held and mode ==
  *		CS_MODE_SYSFS. Otherwise it must be accessed from inside the
  *		spinlock.
+ * @cpu:	The CPU this component is affined to (-1 for not CPU bound).
  * @orphan:	true if the component has connections that haven't been linked.
  * @sysfs_sink_activated: 'true' when a sink has been selected for use via sysfs
  *		by writing a 1 to the 'enable_sink' file.  A sink can be
@@ -286,6 +293,7 @@ struct coresight_device {
 	struct device dev;
 	atomic_t mode;
 	int refcnt;
+	int cpu;
 	bool orphan;
 	/* sink specific fields */
 	bool sysfs_sink_activated;