Dynamic trace id was introduced in coresight subsystem, so trace id is allocated dynamically. However, some hardware ATB source has static trace id and it cannot be changed via software programming. For such source, it can call coresight_get_static_trace_id to get the fixed trace id from device node and pass id to coresight_trace_id_get_static_system_id to reserve the id.

Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com Reviewed-by: Mike Leach mike.leach@linaro.org --- .../hwtracing/coresight/coresight-platform.c | 6 +++ .../hwtracing/coresight/coresight-trace-id.c | 39 +++++++++++++------ .../hwtracing/coresight/coresight-trace-id.h | 9 +++++ include/linux/coresight.h | 1 + 4 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c index 64e171eaad82..633d96b9577a 100644 --- a/drivers/hwtracing/coresight/coresight-platform.c +++ b/drivers/hwtracing/coresight/coresight-platform.c @@ -796,6 +796,12 @@ int coresight_get_cpu(struct device *dev) } EXPORT_SYMBOL_GPL(coresight_get_cpu);

+int coresight_get_static_trace_id(struct device *dev, u32 *id) +{ + return fwnode_property_read_u32(dev_fwnode(dev), "arm,static-trace-id", id); +} +EXPORT_SYMBOL_GPL(coresight_get_static_trace_id); + struct coresight_platform_data * coresight_get_platform_data(struct device *dev) { diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c index d98e12cb30ec..df8fe50b413f 100644 --- a/drivers/hwtracing/coresight/coresight-trace-id.c +++ b/drivers/hwtracing/coresight/coresight-trace-id.c @@ -12,6 +12,12 @@

#include "coresight-trace-id.h"

+enum trace_id_flags { + TRACE_ID_ANY = 0x0, + TRACE_ID_PREFER_ODD = 0x1, + TRACE_ID_REQ_STATIC = 0x2, +}; + /* Default trace ID map. Used in sysfs mode and for system sources */ static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0); static struct coresight_trace_id_map id_map_default = { @@ -74,16 +80,18 @@ static int coresight_trace_id_find_odd_id(struct coresight_trace_id_map *id_map) * Otherwise allocate next available ID. */ static int coresight_trace_id_alloc_new_id(struct coresight_trace_id_map *id_map, - int preferred_id, bool prefer_odd_id) + int preferred_id, unsigned int flags) { int id = 0;

/* for backwards compatibility, cpu IDs may use preferred value */ - if (IS_VALID_CS_TRACE_ID(preferred_id) && - !test_bit(preferred_id, id_map->used_ids)) { - id = preferred_id; - goto trace_id_allocated; - } else if (prefer_odd_id) { + if (IS_VALID_CS_TRACE_ID(preferred_id)) { + if (!test_bit(preferred_id, id_map->used_ids)) { + id = preferred_id; + goto trace_id_allocated; + } else if (flags & TRACE_ID_REQ_STATIC) + return -EINVAL; + } else if (flags & TRACE_ID_PREFER_ODD) { /* may use odd ids to avoid preferred legacy cpu IDs */ id = coresight_trace_id_find_odd_id(id_map); if (id) @@ -153,7 +161,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map */ id = coresight_trace_id_alloc_new_id(id_map, CORESIGHT_LEGACY_CPU_TRACE_ID(cpu), - false); + TRACE_ID_ANY); if (!IS_VALID_CS_TRACE_ID(id)) goto get_cpu_id_out_unlock;

@@ -188,14 +196,14 @@ static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma DUMP_ID_MAP(id_map); }

-static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map) +static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map, + int preferred_id, unsigned int traceid_flags) { unsigned long flags; int id;

spin_lock_irqsave(&id_map->lock, flags); - /* prefer odd IDs for system components to avoid legacy CPU IDS */ - id = coresight_trace_id_alloc_new_id(id_map, 0, true); + id = coresight_trace_id_alloc_new_id(id_map, preferred_id, traceid_flags); spin_unlock_irqrestore(&id_map->lock, flags);

DUMP_ID(id); @@ -255,10 +263,19 @@ EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id_map);

int coresight_trace_id_get_system_id(void) { - return coresight_trace_id_map_get_system_id(&id_map_default); + /* prefer odd IDs for system components to avoid legacy CPU IDS */ + return coresight_trace_id_map_get_system_id(&id_map_default, 0, + TRACE_ID_PREFER_ODD); } EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id);

+int coresight_trace_id_get_static_system_id(int trace_id) +{ + return coresight_trace_id_map_get_system_id(&id_map_default, + trace_id, TRACE_ID_REQ_STATIC); +} +EXPORT_SYMBOL_GPL(coresight_trace_id_get_static_system_id); + void coresight_trace_id_put_system_id(int id) { coresight_trace_id_map_put_system_id(&id_map_default, id); diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h index 9aae50a553ca..db68e1ec56b6 100644 --- a/drivers/hwtracing/coresight/coresight-trace-id.h +++ b/drivers/hwtracing/coresight/coresight-trace-id.h @@ -116,6 +116,15 @@ int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *i */ int coresight_trace_id_get_system_id(void);

+/** + * Allocate a CoreSight static trace ID for a system component. + * + * Used to allocate static IDs for system trace sources such as dummy source. + * + * return: Trace ID or -EINVAL if allocation is impossible. + */ +int coresight_trace_id_get_static_system_id(int id); + /** * Release an allocated system trace ID. * diff --git a/include/linux/coresight.h b/include/linux/coresight.h index c13342594278..129795873072 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -662,6 +662,7 @@ void coresight_relaxed_write64(struct coresight_device *csdev, void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset);

extern int coresight_get_cpu(struct device *dev); +extern int coresight_get_static_trace_id(struct device *dev, u32 *id);

struct coresight_platform_data *coresight_get_platform_data(struct device *dev); struct coresight_connection *

Some dummy source has static trace id configured in HW and it cannot be changed via software programming. Configure the trace id in device tree and reserve the id when device probe.

Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com --- .../sysfs-bus-coresight-devices-dummy-source | 15 ++++ drivers/hwtracing/coresight/coresight-dummy.c | 81 ++++++++++++++++--- 2 files changed, 87 insertions(+), 9 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source b/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source new file mode 100644 index 000000000000..c7d975e75d85 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-dummy-source @@ -0,0 +1,15 @@ +What: /sys/bus/coresight/devices/dummy_source<N>/enable_source +Date: Oct 2024 +KernelVersion: 6.13 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (RW) Enable/disable tracing of dummy source. A sink should be activated + before enabling the source. The path of coresight components linking + the source to the sink is configured and managed automatically by the + coresight framework. + +What: /sys/bus/coresight/devices/dummy_source<N>/traceid +Date: Oct 2024 +KernelVersion: 6.13 +Contact: Mao Jinlong quic_jinlmao@quicinc.com +Description: (R) Show the trace ID that will appear in the trace stream + coming from this trace entity. diff --git a/drivers/hwtracing/coresight/coresight-dummy.c b/drivers/hwtracing/coresight/coresight-dummy.c index bb85fa663ffc..666fd36b81b9 100644 --- a/drivers/hwtracing/coresight/coresight-dummy.c +++ b/drivers/hwtracing/coresight/coresight-dummy.c @@ -11,10 +11,12 @@ #include <linux/pm_runtime.h>

#include "coresight-priv.h" +#include "coresight-trace-id.h"

struct dummy_drvdata { struct device *dev; struct coresight_device *csdev; + u8 traceid; };

DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source"); @@ -72,6 +74,32 @@ static const struct coresight_ops dummy_sink_cs_ops = { .sink_ops = &dummy_sink_ops, };

+/* User can get the trace id of dummy source from this node. */ +static ssize_t traceid_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + unsigned long val; + struct dummy_drvdata *drvdata = dev_get_drvdata(dev->parent); + + val = drvdata->traceid; + return sysfs_emit(buf, "%#lx\n", val); +} +static DEVICE_ATTR_RO(traceid); + +static struct attribute *coresight_dummy_attrs[] = { + &dev_attr_traceid.attr, + NULL, +}; + +static const struct attribute_group coresight_dummy_group = { + .attrs = coresight_dummy_attrs, +}; + +static const struct attribute_group *coresight_dummy_groups[] = { + &coresight_dummy_group, + NULL, +}; + static int dummy_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -79,6 +107,11 @@ static int dummy_probe(struct platform_device *pdev) struct coresight_platform_data *pdata; struct dummy_drvdata *drvdata; struct coresight_desc desc = { 0 }; + int ret = 0, trace_id = 0; + + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); + if (!drvdata) + return -ENOMEM;

if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {

@@ -90,6 +123,26 @@ static int dummy_probe(struct platform_device *pdev) desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_OTHERS; desc.ops = &dummy_source_cs_ops; + desc.groups = coresight_dummy_groups; + + ret = coresight_get_static_trace_id(dev, &trace_id); + if (!ret) { + /* Get the static id if id is set in device tree. */ + ret = coresight_trace_id_get_static_system_id(trace_id); + if (ret < 0) { + dev_err(dev, "Fail to get static id.\n"); + return -EBUSY; + } + } else { + /* Get next available id if id is not set in device tree. */ + trace_id = coresight_trace_id_get_system_id(); + if (trace_id < 0) { + ret = trace_id; + return ret; + } + } + drvdata->traceid = (u8)trace_id; + } else if (of_device_is_compatible(node, "arm,coresight-dummy-sink")) { desc.name = coresight_alloc_device_name(&sink_devs, dev); if (!desc.name) @@ -104,27 +157,35 @@ static int dummy_probe(struct platform_device *pdev) }

pdata = coresight_get_platform_data(dev); - if (IS_ERR(pdata)) - return PTR_ERR(pdata); + if (IS_ERR(pdata)) { + ret = PTR_ERR(pdata); + goto free_id; + } pdev->dev.platform_data = pdata;

- drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); - if (!drvdata) - return -ENOMEM; - drvdata->dev = &pdev->dev; platform_set_drvdata(pdev, drvdata);

desc.pdata = pdev->dev.platform_data; desc.dev = &pdev->dev; drvdata->csdev = coresight_register(&desc); - if (IS_ERR(drvdata->csdev)) - return PTR_ERR(drvdata->csdev); + if (IS_ERR(drvdata->csdev)) { + ret = PTR_ERR(drvdata->csdev); + goto free_id; + }

pm_runtime_enable(dev); dev_dbg(dev, "Dummy device initialized\n");

- return 0; + ret = 0; + goto out; + +free_id: + if (IS_VALID_CS_TRACE_ID(drvdata->traceid)) + coresight_trace_id_put_system_id(drvdata->traceid); + +out: + return ret; }

static void dummy_remove(struct platform_device *pdev) @@ -132,6 +193,8 @@ static void dummy_remove(struct platform_device *pdev) struct dummy_drvdata *drvdata = platform_get_drvdata(pdev); struct device *dev = &pdev->dev;

+ if (IS_VALID_CS_TRACE_ID(drvdata->traceid)) + coresight_trace_id_put_system_id(drvdata->traceid); pm_runtime_disable(dev); coresight_unregister(drvdata->csdev); }