Re: [PATCH v7 07/10] Coresight: Add TPDA link driver

On 09/05/2022 14:39, Mao Jinlong wrote:

TPDA(Trace, Profiling and Diagnostics Aggregator) is to provide packetization, funneling and timestamping of TPDM data. Multiple monitors are connected to different input ports of TPDA.This change is to add tpda enable/disable/probe functions for coresight tpda driver.

---

| TPDM 0| | TPDM 1 | | TPDM 2|

---

 |               |             |
 |_ _ _ _ _ _    |     _ _ _ _ |
             |   |    |
             |   |    |
        ------------------
       |        TPDA      |
        ------------------

Signed-off-by: Tao Zhang quic_taozha@quicinc.com Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com

---

drivers/hwtracing/coresight/Kconfig | 11 + drivers/hwtracing/coresight/Makefile | 1 + drivers/hwtracing/coresight/coresight-tpda.c | 201 +++++++++++++++++++ drivers/hwtracing/coresight/coresight-tpda.h | 33 +++ 4 files changed, 246 insertions(+) create mode 100644 drivers/hwtracing/coresight/coresight-tpda.c create mode 100644 drivers/hwtracing/coresight/coresight-tpda.h

diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig index 5c506a1cd08f..447919565326 100644 --- a/drivers/hwtracing/coresight/Kconfig +++ b/drivers/hwtracing/coresight/Kconfig @@ -205,6 +205,7 @@ config CORESIGHT_TRBE config CORESIGHT_TPDM tristate "CoreSight Trace, Profiling & Diagnostics Monitor driver" select CORESIGHT_LINKS_AND_SINKS

• select CORESIGHT_TPDA help This driver provides support for configuring monitor. Monitors are primarily responsible for data set collection and support the

@@ -214,4 +215,14 @@ config CORESIGHT_TPDM To compile this driver as a module, choose M here: the module will be called coresight-tpdm. +config CORESIGHT_TPDA

• tristate "CoreSight Trace, Profiling & Diagnostics Aggregator driver"
• help

•  This driver provides support for configuring aggregator. This is
  

•  primarily useful for pulling the data sets from one or more
  

•  attached monitors and pushing the resultant data out. Multiple
  

•  monitors are connected on different input ports of TPDA.
  

•  To compile this driver as a module, choose M here: the module will be
  

•  called coresight-tpda.
  

  endif

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile index 6bb9b1746bc7..1712d82e7260 100644 --- a/drivers/hwtracing/coresight/Makefile +++ b/drivers/hwtracing/coresight/Makefile @@ -26,5 +26,6 @@ obj-$(CONFIG_CORESIGHT_CATU) += coresight-catu.o obj-$(CONFIG_CORESIGHT_CTI) += coresight-cti.o obj-$(CONFIG_CORESIGHT_TRBE) += coresight-trbe.o obj-$(CONFIG_CORESIGHT_TPDM) += coresight-tpdm.o +obj-$(CONFIG_CORESIGHT_TPDA) += coresight-tpda.o coresight-cti-y := coresight-cti-core.o coresight-cti-platform.o \ coresight-cti-sysfs.o diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c new file mode 100644 index 000000000000..126286e89679 --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-tpda.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
• */

+#include <linux/amba/bus.h> +#include <linux/bitmap.h> +#include <linux/coresight.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/fs.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-tpda.h" +#include "coresight-trace-id.h"

+DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");

+/* Settings pre enabling port control register */ +static void tpda_enable_pre_port(struct tpda_drvdata *drvdata) +{

• u32 val;
• val = readl_relaxed(drvdata->base + TPDA_CR);
• /* Bits 6 ~ 12 is for atid value */

minor nit, please could we use FIELD_PREP() and define the ATID field in the TPDA_CR accordingly ?

• val |= (drvdata->atid << 6)

then we could have :

val |= FIELD_PREP(TPDA_CR_ATID, drvdata->atid);

• writel_relaxed(val, drvdata->base + TPDA_CR);

+}

+static void tpda_enable_port(struct tpda_drvdata *drvdata, int port) +{

• u32 val;
• val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
• /* Enable the port */
• val |= TPDA_Pn_CR_ENA;
• writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));

+}

+static void _tpda_enable(struct tpda_drvdata *drvdata, int port)

minor nit: Similar to the tpdm, comment please use __tpda_{enable,disable}()

+{

• CS_UNLOCK(drvdata->base);
• if (!drvdata->enable)

• tpda_enable_pre_port(drvdata);
  

• tpda_enable_port(drvdata, port);
• CS_LOCK(drvdata->base);

+}

+static int tpda_enable(struct coresight_device *csdev, int inport, int outport) +{

• struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
• mutex_lock(&drvdata->lock);
• _tpda_enable(drvdata, inport);
• drvdata->enable = true;

I am wondering if this is good enough ? Do we need a refcount ? e.g, multiple TPDMs could be enabled independently and disabled indpendently. And the tpda must stay alive until the last "source" is gone away ?

• mutex_unlock(&drvdata->lock);
• dev_info(drvdata->dev, "TPDA inport %d enabled\n", inport);
• return 0;

+}

+static void _tpda_disable(struct tpda_drvdata *drvdata, int port) +{

• u32 val;
• CS_UNLOCK(drvdata->base);
• val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
• val &= ~TPDA_Pn_CR_ENA;
• writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
• CS_LOCK(drvdata->base);

+}

+static void tpda_disable(struct coresight_device *csdev, int inport,

• 	   int outport)
  

+{

• struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
• mutex_lock(&drvdata->lock);
• _tpda_disable(drvdata, inport);
• drvdata->enable = false;

This is not sufficient. We need to make sure the TPDA has a refcount of the enabled ports.

• mutex_unlock(&drvdata->lock);
• dev_info(drvdata->dev, "TPDA inport %d disabled\n", inport);

+}

+static const struct coresight_ops_link tpda_link_ops = {

• .enable = tpda_enable,
• .disable = tpda_disable,

+};

+static const struct coresight_ops tpda_cs_ops = {

• .link_ops = &tpda_link_ops,

+};

+static int tpda_init_default_data(struct tpda_drvdata *drvdata) +{

• int atid;
• /*

• * TPDA must has a unique atid. This atid can uniquely
  

• * identify the TPDM trace source connect to the TPDA.
  

nit: s/connect/connected/

Also how do we identify the different TPDM sources connected using a single atid ? Looking at the patch description it is possible to have multiple TPDMs connected to a single TPDA.

• */
  

• atid = coresight_trace_id_get_system_id(coresight_get_trace_id_map());
• if (atid < 0)

• return atid;
  

• drvdata->atid = atid;
• return 0;

+}

+static int tpda_probe(struct amba_device *adev, const struct amba_id *id) +{

• int ret;
• struct device *dev = &adev->dev;
• struct coresight_platform_data *pdata;
• struct tpda_drvdata *drvdata;
• struct coresight_desc desc = { 0 };
• 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;
  

• mutex_init(&drvdata->lock);
• ret = tpda_init_default_data(drvdata);
• if (ret)

• return ret;
  

• desc.name = coresight_alloc_device_name(&tpda_devs, dev);
• if (!desc.name)

• return -ENOMEM;
  

• desc.type = CORESIGHT_DEV_TYPE_LINK;
• desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG;
• desc.ops = &tpda_cs_ops;
• desc.pdata = adev->dev.platform_data;
• desc.dev = &adev->dev;

desc.access must be initialised.

• drvdata->csdev = coresight_register(&desc);
• if (IS_ERR(drvdata->csdev))

• return PTR_ERR(drvdata->csdev);
  

• pm_runtime_put(&adev->dev);
• dev_dbg(drvdata->dev, "TPDA initialized\n");
• return 0;

+}

+static void __exit tpda_remove(struct amba_device *adev) +{

• struct tpda_drvdata *drvdata = dev_get_drvdata(&adev->dev);
• coresight_unregister(drvdata->csdev);

+}

+/*

• • Different TPDA has different periph id.
• • The difference is 0-7 bits' value. So ignore 0-7 bits.
• */

+static struct amba_id tpda_ids[] = {

• {

• .id     = 0x000f0f00,
  

• .mask   = 0x000fff00,
  

• },
• { 0, 0},

+};

+static struct amba_driver tpda_driver = {

• .drv = {

• .name   = "coresight-tpda",
  

• .owner	= THIS_MODULE,
  

• .suppress_bind_attrs = true,
  

• },
• .probe = tpda_probe,
• .remove = tpda_remove,
• .id_table = tpda_ids,

+};

+module_amba_driver(tpda_driver);

+MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Trace, Profiling & Diagnostic Aggregator driver"); diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/hwtracing/coresight/coresight-tpda.h new file mode 100644 index 000000000000..6df1b72b3b76 --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-tpda.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
• */

+#ifndef _CORESIGHT_CORESIGHT_TPDA_H +#define _CORESIGHT_CORESIGHT_TPDA_H

+#define TPDA_CR (0x000) +#define TPDA_Pn_CR(n) (0x004 + (n * 4)) +/* Aggregator port enable bit */ +#define TPDA_Pn_CR_ENA BIT(0)

+#define TPDA_MAX_INPORTS 32

Please add the bit fields for TPDA_CR_ATID here and use the FIELD_PREP()

#define TPDA_CR_ATID GENMASK(12, 6)

+/**

• • struct tpda_drvdata - specifics associated to an TPDA component
• • @base: memory mapped base address for this component.
• • @dev: The device entity associated to this component.
• • @csdev: component vitals needed by the framework.
• • @lock: lock for the enable value.
• • @enable: enable status of the component.
• */

+struct tpda_drvdata {

• void __iomem *base;
• struct device *dev;
• struct coresight_device *csdev;
• struct mutex lock;

Why mutex and not spinlock ?

• bool enable;
• u32 atid;

u8 atid ?

Suzuki