| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <4ddc9078-1059-45a2-8f44-c904d62c854f@arm.com>
Date: Mon, 21 Oct 2024 13:36:32 +0100
From: Suzuki K Poulose <suzuki.poulose@....com>
To: Mao Jinlong <quic_jinlmao@...cinc.com>, Mike Leach
<mike.leach@...aro.org>, James Clark <james.clark@....com>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Cc: coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v5 3/3] coresight: dummy: Add static trace id support for
dummy source
On 21/10/2024 13:31, Suzuki K Poulose wrote:
> On 18/10/2024 04:22, Mao Jinlong wrote:
>> 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@...cinc.com>
>> ---
>> .../sysfs-bus-coresight-devices-dummy-source | 15 +++++
>> drivers/hwtracing/coresight/coresight-dummy.c | 59 +++++++++++++++++--
>> 2 files changed, 70 insertions(+), 4 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@...cinc.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@...cinc.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..602a7e89e311 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 scnprintf(buf, PAGE_SIZE, "%#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, trace_id;
>> +
>> + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
>> + if (!drvdata)
>> + return -ENOMEM;
>> if (of_device_is_compatible(node, "arm,coresight-dummy-source")) {
>> @@ -90,6 +123,25 @@ 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);
This may be worth an error message, it is a rare one. Othewise, there is
no clue on what caused the failure. Or have a specific error code as a
result ?
>> + if (ret < 0)
>> + return ret;
e.g., return -EBUSY ? /* Device or resource not available */
>> +
>> + } 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)
>> @@ -108,10 +160,6 @@ static int dummy_probe(struct platform_device *pdev)
>> return PTR_ERR(pdata);
>> 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);
Additionally we should drop the system_id if registering the coresight
device fails.
Suzuki
>> @@ -131,7 +179,10 @@ static void dummy_remove(struct platform_device
>> *pdev)
>> {
>> struct dummy_drvdata *drvdata = platform_get_drvdata(pdev);
>> struct device *dev = &pdev->dev;
>> + struct device_node *node = dev->of_node;
>
> ^^ Why is this needed ? The rest looks fine to me
>
>> + if (IS_VALID_CS_TRACE_ID(drvdata->traceid))
>> + coresight_trace_id_put_system_id(drvdata->traceid);
>> pm_runtime_disable(dev);
>> coresight_unregister(drvdata->csdev);
>> }
>
Powered by blists - more mailing lists