Add a devicetree binding document for ftrace node. Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> --- .../devicetree/bindings/tracing/ftrace.yaml | 170 ++++++++++++++++++++ 1 file changed, 170 insertions(+) create mode 100644 Documentation/devicetree/bindings/tracing/ftrace.yaml diff --git a/Documentation/devicetree/bindings/tracing/ftrace.yaml b/Documentation/devicetree/bindings/tracing/ftrace.yaml new file mode 100644 index 000000000000..cbd7af986c38 --- /dev/null +++ b/Documentation/devicetree/bindings/tracing/ftrace.yaml @@ -0,0 +1,170 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +# Copyright 2019 Linaro Ltd. +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/tracing/ftrace.yaml#"; +$schema: "http://devicetree.org/meta-schemas/core.yaml#"; + +title: Ftrace setting devicetree binding + +maintainers: + - Masami Hiramatsu <mhiramat@xxxxxxxxxx> + +description: | + Boot-time ftrace tracing setting via devicetree. Users can use devicetree node + for programming ftrace boot-time tracing. + +properties: + compatible: + items: + - const: linux,ftrace + + trace-clock: + allOf: + - $ref: /schemas/types.yaml#/definitions/string + - enum: [ global, local, counter, uptime, perf, mono, mono_raw, boot, ppc-tb, x86-tsc ] + description: Specify which clock method is used for trace-clock. + + dump-on-oops: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - enum: [0, 1, 2] + description: | + A neumerical flag to enable ftrace dump on Kernel Oops. 0 means no dump, + 1 means dump on the origin cpu of the oops, and means dump on all cpus. + + traceoff-on-warning: + $ref: /schemas/types.yaml#/definitions/flag + description: A flag to stop tracing on warning. + + tp-printk: + $ref: /schemas/types.yaml#/definitions/flag + description: A flag to send tracing output to printk buffer too. + + alloc-snapshot: + $ref: /schemas/types.yaml#/definitions/flag + description: | + A flag to allocate snapshot buffer at boot. This will be required if you + use "snapshot" action on some events. + + buffer-size-kb: + allOf: + - $ref: /schemas/types.yaml#/definitions/uint32 + - minimum: 1 + description: | + The size of per-cpu tracing buffer in KByte. Note that the size must be + larger than page size, and total size of buffers depends on the number + of CPUs. + + events: + minItems: 1 + $ref: /schemas/types.yaml#/definitions/string-array + description: | + A string array of enabling events (including wildcard patterns). + See Documentation/trace/events.rst for detail. + + options: + minItems: 1 + $ref: /schemas/types.yaml#/definitions/string-array + description: | + A string array of trace options for ftrace to control what gets printed + in the trace output or manipulate the tracers. + See Documentation/trace/ftrace.rst#trace_options for detail. + + tracer: + default: nop + $ref: /schemas/types.yaml#/definitions/string + description: A string of the tracer to start up. + +patternProperties: + "event[0-9a-fA-F]+$": + type: object + + description: | + event-* properties are child nodes for per-event settings. It is also + able to define new kprobe events and synthetic events. Note that you + can not define both "probes" and "fields" properties on same event. + + properties: + event: + $ref: /schemas/types.yaml#/definitions/string + description: | + Event name string formatted as "GROUP:EVENT". For synthetic event, + you must use "synthetic" for group name. For kprobe and synthetic + event, you can ommit the group name. + + probes: + minItems: 1 + $ref: /schemas/types.yaml#/definitions/string-array + description: | + A string array of kprobe event definitions, including location + (symbol+offset) and event arguments. + See Documentation/trace/kprobetrace.rst for detail. + + fields: + minItems: 1 + $ref: /schemas/types.yaml#/definitions/string-array + description: | + A string of synthetic event's fields definition. Note that you + don't need to repeat event name. + + filter: + $ref: /schemas/types.yaml#/definitions/string + description: A string of event filter rule + + actions: + minItems: 1 + $ref: /schemas/types.yaml#/definitions/string-array + description: A string array of event trigger actions. + + enable: + type: boolean + description: | + A flag to enable event. Note that the event is not enabled by + default. (But actions will set the event soft-disabled) + + oneOf: + - required: + - event + - required: + - event + - probes + - required: + - event + - fields + +required: + - compatible + +examples: + - | + ftrace { + compatible = "linux,ftrace"; + events = "initcall:*"; + tp-printk; + buffer-size-kb = <0x400>; + event0 { + event = "task:task_newtask"; + filter = "pid < 128"; + enable; + }; + event1 { + event = "kprobes:vfs_read"; + probes = "vfs_read $arg1 $arg2"; + filter = "common_pid < 200"; + }; + event2 { + event = "initcall_latency"; + fields = "unsigned long func", "u64 lat"; + actions = "hist:keys=func.sym,lat:vals=lat:sort=lat"; + }; + event3 { + event = "initcall:initcall_start"; + actions = "hist:keys=func:ts0=common_timestamp.usecs"; + }; + event4 { + event = "initcall:initcall_finish"; + actions = "hist:keys=func:lat=common_timestamp.usecs-$ts0:onmatch(initcall.initcall_start).initcall_latency(func,$lat)"; + }; + + };
