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Message-ID: <d949c0e7-e791-45cf-89f3-82a26f70382b@quicinc.com>
Date: Fri, 23 May 2025 16:37:56 +0800
From: Yuanfang Zhang <quic_yuanfang@...cinc.com>
To: Leo Yan <leo.yan@....com>
CC: Suzuki K Poulose <suzuki.poulose@....com>,
Mike Leach
<mike.leach@...aro.org>,
James Clark <james.clark@...aro.org>, Rob Herring
<robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley
<conor+dt@...nel.org>,
Alexander Shishkin
<alexander.shishkin@...ux.intel.com>,
<kernel@....qualcomm.com>, <linux-arm-msm@...r.kernel.org>,
<coresight@...ts.linaro.org>, <linux-arm-kernel@...ts.infradead.org>,
<devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v6 2/2] coresight: add coresight Trace Network On Chip
driver
On 5/22/2025 9:05 PM, Leo Yan wrote:
> Hi Yuanfang,
>
> On Thu, May 22, 2025 at 04:07:52PM +0800, Yuanfang Zhang wrote:
>> Add a driver to support Coresight device Trace Network On Chip (TNOC),
>> which is an integration hierarchy integrating functionalities of TPDA
>> and funnels. It aggregates the trace and transports to coresight trace
>> bus.
>
> The code quality is good for me. However, I still have several minor
> comments.
>
>> Compared to current configuration, it has the following advantages:
>> 1. Reduce wires between subsystems.
>> 2. Continue cleaning the infrastructure.
>> 3. Reduce Data overhead by transporting raw data from source to target.
>>
>> +------------------------+ +-------------------------+
>> | Video Subsystem | |Video Subsystem |
>> | +-------------+ | | +------------+ |
>> | | Video TPDM | | | | Video TPDM | |
>> | +-------------+ | | +------------+ |
>> | | | | | |
>> | v | | v |
>> | +---------------+ | | +-----------+ |
>> | | Video funnel | | | |Video TNOC | |
>> | +---------------+ | | +-----------+ |
>> +------------|-----------+ +------------|------------+
>> | |
>> v-----+ |
>> +--------------------|---------+ |
>> | Multimedia v | |
>> | Subsystem +--------+ | |
>> | | TPDA | | v
>> | +----|---+ | +---------------------+
>> | | | | Aggregator TNOC |
>> | | | +----------|----------+
>> | +-- | |
>> | | | |
>> | | | |
>> | +------v-----+ | |
>> | | Funnel | | |
>> | +------------+ | |
>> +----------------|-------------+ |
>> | |
>> v v
>> +--------------------+ +------------------+
>> | Coresight Sink | | Coresight Sink |
>> +--------------------+ +------------------+
>>
>> Current Configuration TNOC
>>
>> Signed-off-by: Yuanfang Zhang <quic_yuanfang@...cinc.com>
>> ---
>> drivers/hwtracing/coresight/Kconfig | 13 ++
>> drivers/hwtracing/coresight/Makefile | 1 +
>> drivers/hwtracing/coresight/coresight-tnoc.c | 192 +++++++++++++++++++++++++++
>> drivers/hwtracing/coresight/coresight-tnoc.h | 34 +++++
>> 4 files changed, 240 insertions(+)
>>
>> diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
>> index ecd7086a5b83e86b6bc8ea039d6d26a628334ed3..f20600d58f38568f8178f69d3f678c2df2cbca7e 100644
>> --- a/drivers/hwtracing/coresight/Kconfig
>> +++ b/drivers/hwtracing/coresight/Kconfig
>> @@ -259,4 +259,17 @@ config CORESIGHT_DUMMY
>>
>> To compile this driver as a module, choose M here: the module will be
>> called coresight-dummy.
>> +
>> +config CORESIGHT_TNOC
>> + tristate "Coresight Trace Network On Chip driver"
>> + help
>> + This driver provides support for Trace Network On Chip (TNOC) component.
>> + TNOC is an interconnect used to collect traces from various subsystems
>> + and transport to a coresight trace sink. It sits in the different
>> + tiles of SOC and aggregates the trace local to the tile and transports
>> + it another tile or to coresight trace sink eventually.
>> +
>> + To compile this driver as a module, choose M here: the module will be
>> + called coresight-tnoc.
>> +
>> endif
>> diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
>> index 8e62c3150aebd1e82b445fafc97a0a9b44397b0e..880e9ed6bfe9c711492c6a2cd972751f56dd8010 100644
>> --- a/drivers/hwtracing/coresight/Makefile
>> +++ b/drivers/hwtracing/coresight/Makefile
>> @@ -34,6 +34,7 @@ obj-$(CONFIG_CORESIGHT_SINK_TPIU) += coresight-tpiu.o
>> obj-$(CONFIG_CORESIGHT_SINK_ETBV10) += coresight-etb10.o
>> obj-$(CONFIG_CORESIGHT_LINKS_AND_SINKS) += coresight-funnel.o \
>> coresight-replicator.o
>> +obj-$(CONFIG_CORESIGHT_TNOC) += coresight-tnoc.o
>> obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o
>> coresight-etm3x-y := coresight-etm3x-core.o coresight-etm-cp14.o \
>> coresight-etm3x-sysfs.o
>> diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..5658501155d322d28e87ff820c7ba8b787eff7ce
>> --- /dev/null
>> +++ b/drivers/hwtracing/coresight/coresight-tnoc.c
>> @@ -0,0 +1,192 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> + #include <linux/amba/bus.h>
>> + #include <linux/coresight.h>
>> + #include <linux/device.h>
>> + #include <linux/io.h>
>> + #include <linux/kernel.h>
>> + #include <linux/module.h>
>> + #include <linux/of.h>
>> + #include <linux/platform_device.h>
>> +
>> +#include "coresight-priv.h"
>> +#include "coresight-tnoc.h"
>> +#include "coresight-trace-id.h"
>> +
>> +DEFINE_CORESIGHT_DEVLIST(trace_noc_devs, "traceNoc");
>> +
>> +static void trace_noc_enable_hw(struct trace_noc_drvdata *drvdata)
>> +{
>> + u32 val;
>> +
>> + /* Set ATID */
>> + writel_relaxed(drvdata->atid, drvdata->base + TRACE_NOC_XLD);
>> +
>> + /* Set the data word count between 'SYNC' packets */
>> + writel_relaxed(TRACE_NOC_SYNC_INTERVAL, drvdata->base + TRACE_NOC_SYNCR);
>> +
>> + /* Set the Control register:
>> + * - Set the FLAG packets to 'FLAG' packets
>> + * - Set the FREQ packets to 'FREQ_TS' packets
>> + * - Enable generation of output ATB traffic
>> + */
>> +
>> + val = readl_relaxed(drvdata->base + TRACE_NOC_CTRL);
>> +
>> + val &= ~TRACE_NOC_CTRL_FLAGTYPE;
>> + val |= TRACE_NOC_CTRL_FREQTYPE;
>> + val |= TRACE_NOC_CTRL_PORTEN;
>> +
>> + writel(val, drvdata->base + TRACE_NOC_CTRL);
>> +}
>> +
>> +static int trace_noc_enable(struct coresight_device *csdev, struct coresight_connection *inport,
>> + struct coresight_connection *outport)
>> +{
>> + struct trace_noc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>> +
>> + spin_lock(&drvdata->spinlock);
>
> scoped_guard(spinlock, &drvdata->spinlock) {
>
> }
>
Done in next patch.
>> + if (csdev->refcnt == 0)
>> + trace_noc_enable_hw(drvdata);
>> +
>> + csdev->refcnt++;
>> + spin_unlock(&drvdata->spinlock);
>> +
>> + dev_dbg(drvdata->dev, "Trace NOC is enabled\n");
>> + return 0;
>> +}
>> +
>> +static void trace_noc_disable_hw(struct trace_noc_drvdata *drvdata)
>> +{
>> + writel(0x0, drvdata->base + TRACE_NOC_CTRL);
>> +}
>
> It is not necessary to use a function to encapsulate single operations.
>
> Please drop the function trace_noc_disable_hw() and directly use
> writel() in the call site.
Done in next patch.
>
>> +
>> +static void trace_noc_disable(struct coresight_device *csdev, struct coresight_connection *inport,
>> + struct coresight_connection *outport)
>> +{
>> + struct trace_noc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>> +
>> + spin_lock(&drvdata->spinlock);
>> + if (--csdev->refcnt == 0)
>> + trace_noc_disable_hw(drvdata);
>> +
>> + spin_unlock(&drvdata->spinlock);
>> + dev_dbg(drvdata->dev, "Trace NOC is disabled\n");
>> +}
>> +
>> +static int trace_noc_id(struct coresight_device *csdev, __maybe_unused enum cs_mode mode,
>> + __maybe_unused struct coresight_device *sink)
>> +{
>> + struct trace_noc_drvdata *drvdata;
>> +
>> + drvdata = dev_get_drvdata(csdev->dev.parent);
>> +
>> + return drvdata->atid;
>> +}
>> +
>> +static const struct coresight_ops_link trace_noc_link_ops = {
>> + .enable = trace_noc_enable,
>> + .disable = trace_noc_disable,
>> +};
>> +
>> +static const struct coresight_ops trace_noc_cs_ops = {
>> + .trace_id = trace_noc_id,
>> + .link_ops = &trace_noc_link_ops,
>> +};
>> +
>> +static int trace_noc_init_default_data(struct trace_noc_drvdata *drvdata)
>> +{
>> + int atid;
>> +
>> + atid = coresight_trace_id_get_system_id();
>> + if (atid < 0)
>> + return atid;
>> +
>> + drvdata->atid = atid;
>> +
>> + return 0;
>> +}
>> +
>> +static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id)
>> +{
>> + struct device *dev = &adev->dev;
>> + struct coresight_platform_data *pdata;
>> + struct trace_noc_drvdata *drvdata;
>> + struct coresight_desc desc = { 0 };
>> + int ret;
>> +
>> + desc.name = coresight_alloc_device_name(&trace_noc_devs, dev);
>> + if (!desc.name)
>> + return -ENOMEM;
>> +
>> + pdata = coresight_get_platform_data(dev);
>> + if (IS_ERR(pdata))
>> + return PTR_ERR(pdata);
>> + adev->dev.platform_data = pdata;
>> +
>> + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
>> + if (!drvdata)
>> + return -ENOMEM;
>> +
>> + drvdata->dev = &adev->dev;
>> + dev_set_drvdata(dev, drvdata);
>> +
>> + drvdata->base = devm_ioremap_resource(dev, &adev->res);
>> + if (!drvdata->base)
>> + return -ENOMEM;
>> +
>> + spin_lock_init(&drvdata->spinlock);
>> +
>> + ret = trace_noc_init_default_data(drvdata);
>> + if (ret)
>> + return ret;
>> +
>> + desc.ops = &trace_noc_cs_ops;
>> + desc.type = CORESIGHT_DEV_TYPE_LINK;
>> + desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
>> + desc.pdata = adev->dev.platform_data;
>> + desc.dev = &adev->dev;
>> + desc.access = CSDEV_ACCESS_IOMEM(drvdata->base);
>> + drvdata->csdev = coresight_register(&desc);
>> + if (IS_ERR(drvdata->csdev))
>> + return PTR_ERR(drvdata->csdev);
>
> Invoke coresight_trace_id_put_system_id() for registration failure.
>
Done in next patch.
>> +
>> + pm_runtime_put(&adev->dev);
>> +
>> + return 0;
>> +}
>> +
>> +static void trace_noc_remove(struct amba_device *adev)
>> +{
>> + struct trace_noc_drvdata *drvdata = dev_get_drvdata(&adev->dev);
>> +
>> + coresight_trace_id_put_system_id(drvdata->atid);
>> + coresight_unregister(drvdata->csdev);
>> +}
>> +
>> +static struct amba_id trace_noc_ids[] = {
>> + {
>> + .id = 0x000f0c00,
>> + .mask = 0x00ffff00,
>> + },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(amba, trace_noc_ids);
>> +
>> +static struct amba_driver trace_noc_driver = {
>> + .drv = {
>> + .name = "coresight-trace-noc",
>> + .suppress_bind_attrs = true,
>> + },
>> + .probe = trace_noc_probe,
>> + .remove = trace_noc_remove,
>> + .id_table = trace_noc_ids,
>> +};
>> +
>> +module_amba_driver(trace_noc_driver);
>> +
>> +MODULE_LICENSE("GPL");
>> +MODULE_DESCRIPTION("Trace NOC driver");
>> diff --git a/drivers/hwtracing/coresight/coresight-tnoc.h b/drivers/hwtracing/coresight/coresight-tnoc.h
>> new file mode 100644
>> index 0000000000000000000000000000000000000000..34c696965ec50e3664d55e04e22d5b854d6937a7
>> --- /dev/null
>> +++ b/drivers/hwtracing/coresight/coresight-tnoc.h
>> @@ -0,0 +1,34 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Copyright (c) 2025 Qualcomm Innovation Center, Inc. All rights reserved.
>> + */
>> +
>> +#define TRACE_NOC_CTRL 0x008
>> +#define TRACE_NOC_XLD 0x010
>> +#define TRACE_NOC_FREQVAL 0x018
>> +#define TRACE_NOC_SYNCR 0x020
>> +
>> +/* Enable generation of output ATB traffic.*/
>> +#define TRACE_NOC_CTRL_PORTEN BIT(0)
>> +/* Sets the type of issued ATB FLAG packets.*/
>> +#define TRACE_NOC_CTRL_FLAGTYPE BIT(7)
>> +/* Sets the type of issued ATB FREQ packet*/
>> +#define TRACE_NOC_CTRL_FREQTYPE BIT(8)
>> +
>> +#define TRACE_NOC_SYNC_INTERVAL 0xFFFF
>> +
>> +/*
>> + * struct trace_noc_drvdata - specifics associated to a trace noc component
>> + * @base: memory mapped base address for this component.
>> + * @dev: device node for trace_noc_drvdata.
>> + * @csdev: component vitals needed by the framework.
>> + * @spinlock: only one at a time pls.
>
> Change to "serialize enable/disable operations" ?
Done in next patch.
>
>> + * @atid: id for the trace packet.
>> + */
>> +struct trace_noc_drvdata {
>> + void __iomem *base;
>> + struct device *dev;
>> + struct coresight_device *csdev;
>> + spinlock_t spinlock; /* lock for the drvdata. */
>
> Remove comment "lock for the drvdata" ? As it has been described in
> the head comments.
it was suggested by "checkpatch.pl", removed in next patch.
>
>> + u32 atid;
>> +};
>
> Please move the content into coresight-tnoc.c and drop the header.
>
> The definitions are private for the driver, it is not necessary to
> maintain them in a header.
Done in next patch.
>
>
>>
>> --
>> 2.34.1
>>
>> _______________________________________________
>> CoreSight mailing list -- coresight@...ts.linaro.org
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