[PATCH v3 2/2] coresight: add coresight Trace Network On Chip driver
Suzuki K Poulose
suzuki.poulose at arm.com
Fri Apr 11 02:59:46 PDT 2025
On 11/04/2025 09:57, 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.
>
> 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
> | +----|---+ | +---------------------+
> | | | | Aggoregator TNOC |
> | | | +----------|----------+
> | +-- | |
> | | | |
> | | | |
> | +------v-----+ | |
> | | Funnel | | |
> | +------------+ | |
> +----------------|-------------+ |
> | |
> v v
> +--------------------+ +------------------+
> | Coresight Sink | | Coresight Sink |
> +--------------------+ +------------------+
If each NOC has TraceID, how do you reliably decode the trace ?
Is there a single NOC/TPDA in the path from Source to sink ?
>
> Current Configuration TNOC
>
> Signed-off-by: Yuanfang Zhang <quic_yuanfang at quicinc.com>
> ---
> drivers/hwtracing/coresight/Kconfig | 13 ++
> drivers/hwtracing/coresight/Makefile | 1 +
> drivers/hwtracing/coresight/coresight-tnoc.c | 186 +++++++++++++++++++++++++++
> drivers/hwtracing/coresight/coresight-tnoc.h | 34 +++++
> 4 files changed, 234 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..2ec4ead892f0166a3e84f777679c0f73f5da0e83
> --- /dev/null
> +++ b/drivers/hwtracing/coresight/coresight-tnoc.c
> @@ -0,0 +1,186 @@
> +// 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);
> +
> + /* Config sync CR */
> + writel_relaxed(TRACE_NOC_SYN_VAL, drvdata->base + TRACE_NOC_SYNCR);
See my comment below about SYN_VAL. Please add a meaningful comment than
explaining what is obvious from the code.
> +
> + /* Set Ctrl register */
Same here. Comment need not explain what is obvious from the code. But
a description of why we choose the values below is helpful.
> + val = readl_relaxed(drvdata->base + TRACE_NOC_CTRL);
> +
> + val = val & ~TRACE_NOC_CTRL_FLAGTYPE;
> + val = val | TRACE_NOC_CTRL_FREQTYPE;
> + val = 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);
> + 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);
> +}
> +
> +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);
> +
> + 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 = 0x000fff00,
Is the mask sufficient ? fyi, the tpdm mask was fixed in
commit c8ea5f41b421.
Suzuk
> + },
> + {},
> +};
> +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..1291a153412c1c92be530cffe25fb56c2fca0395
> --- /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_SYN_VAL 0xFFFF
TRACE_NOC_SYNCR_xx ?
What does VAL indicate ? It sounds too generic to indicate anything
meaningful. Does it mean, allow all inputs ?
Suzuki
> +
> +/*
> + * 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.
> + * @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. */
> + u32 atid;
> +};
>
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