Re: [PATCH v5 08/14] coresight: cti: Enable CTI associated with devices.

Mathieu Poirier
2019-11-25T22:48:37Z

On Tue, Nov 19, 2019 at 11:19:06PM +0000, Mike Leach wrote:
> The CoreSight subsystem enables a path of devices from source to sink.
> Any CTI devices associated with the path devices must be enabled at the
> same time.
>
> This patch adds an associated coresight_device element to the main
> coresight device structure, and uses this to create associations between
> the CTI and other devices based on the device tree data. The associated
> device element is used to enable CTI in conjunction with the path elements.
>
> CTI devices are reference counted so where a single CTI is associated with
> multiple elements on the path, it will be enabled on the first associated
> device enable, and disabled with the last associated device disable.
>
> Signed-off-by: Mike Leach <mike.leach@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-cti.c | 87 +++++++++++++++++++
> .../hwtracing/coresight/coresight-platform.c | 23 +++++
> drivers/hwtracing/coresight/coresight-priv.h | 6 ++
> drivers/hwtracing/coresight/coresight.c | 58 +++++++++++--
> include/linux/coresight.h | 5 ++
> 5 files changed, 173 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
> index 369488dd7b8e..cf116463149a 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.c
> +++ b/drivers/hwtracing/coresight/coresight-cti.c
> @@ -440,6 +440,90 @@ int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
> return err;
> }
>
> +/*
> + * Look for a matching connection device name in the list of
> + * connections. If found then swap in the csdev name and return
> + * found.
> + */
> +static bool
> +cti_match_con_name(struct cti_device *ctidev, const char *node_name,
> + const char *csdev_name)
> +{
> + struct cti_trig_con *trig_con;
> +
> + list_for_each_entry(trig_con, &ctidev->trig_cons, node) {
> + if (trig_con->con_dev_name) {
> + if (!strcmp(node_name, trig_con->con_dev_name)) {
> + /* match: so swap in csdev name */
> + kfree(trig_con->con_dev_name);
> + trig_con->con_dev_name =
> + kstrdup(csdev_name, GFP_KERNEL);
> + return true;
> + }
> + }
> + }
> + return false;
> +}
> +
> +/*
> + * Search the cti list to add an associated CTI into the supplied CS device
> + * This will set the association if CTI declared before the CS device
> + */
> +void cti_add_assoc_to_csdev(struct coresight_device *csdev)
> +{
> + struct cti_drvdata *ect_item;
> + struct cti_device *ctidev;
> + const char *node_name = NULL, *csdev_name;
> +
> + /* protect the list */
> + mutex_lock(&ect_mutex);
> +
> + /* exit if current is an ECT device.*/
> + if ((csdev->type == CORESIGHT_DEV_TYPE_ECT) || list_empty(&ect_net))
> + goto cti_add_done;
> +
> + /* if we didn't find the csdev previously we used the fwnode name */
> + node_name = coresight_get_fwnode_name(csdev->dev.parent);
> +
> + if (!node_name)
> + goto cti_add_done;
> +
> + /* this is the name we want to use for the association */
> + csdev_name = dev_name(&csdev->dev);
> +
> + /* for each CTI in list... */
> + list_for_each_entry(ect_item, &ect_net, node) {
> + ctidev = &ect_item->ctidev;
> + if (cti_match_con_name(ctidev, node_name, csdev_name)) {
> + /*
> + * if we found a matching name then update the
> + * association pointers.
> + */
> + csdev->ect_dev = ect_item->csdev;
> + goto cti_add_done;
> + }
> + }
> +cti_add_done:
> + mutex_unlock(&ect_mutex);
> +}
> +EXPORT_SYMBOL_GPL(cti_add_assoc_to_csdev);
> +
> +/*
> + * Update the cross references where the associated device was found
> + * while we were building the connection info. This will occur if the
> + * assoc device was registered before the CTI.
> + */
> +static void cti_update_conn_xrefs(struct cti_drvdata *drvdata)
> +{
> + struct cti_trig_con *tc;
> + struct cti_device *ctidev = &drvdata->ctidev;
> +
> + list_for_each_entry(tc, &ctidev->trig_cons, node) {
> + if (tc->con_dev)
> + tc->con_dev->ect_dev = drvdata->csdev;
> + }
> +}
> +
> /** cti ect operations **/
> int cti_enable(struct coresight_device *csdev)
> {
> @@ -574,6 +658,9 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
> drvdata->csdev_release = drvdata->csdev->dev.release;
> drvdata->csdev->dev.release = cti_device_release;
>
> + /* set any cross references */
> + cti_update_conn_xrefs(drvdata);
> +
> /* all done - dec pm refcount */
> pm_runtime_put(&adev->dev);
> dev_info(&drvdata->csdev->dev, "CTI initialized\n");
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index 3c5bee429105..6721cb1af5fe 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -293,6 +293,12 @@ static int of_get_coresight_platform_data(struct device *dev,
>
> return 0;
> }
> +
> +static inline const char *of_coresight_get_node_name(struct device *dev)
> +{
> + return dev->of_node->full_name;
> +}
> +
> #else
> static inline int
> of_get_coresight_platform_data(struct device *dev,
> @@ -305,6 +311,11 @@ static inline int of_coresight_get_cpu(struct device *dev)
> {
> return -ENODEV;
> }
> +
> +static inline const char *of_coresight_get_node_name(struct device *dev)
> +{
> + return NULL;
> +}
> #endif
>
> #ifdef CONFIG_ACPI
> @@ -766,6 +777,18 @@ static inline int acpi_coresight_get_cpu(struct device *dev)
> }
> #endif
>
> +const char *coresight_get_fwnode_name(struct device *dev)
> +{
> + const char *node_name = NULL;
> + struct fwnode_handle *fwnode = dev_fwnode(dev);
> +
> + if (is_of_node(fwnode))
> + node_name = of_coresight_get_node_name(dev);
> +
> + return node_name;
> +}
> +EXPORT_SYMBOL_GPL(coresight_get_fwnode_name);
> +
> int coresight_get_cpu(struct device *dev)
> {
> if (is_of_node(dev->fwnode))
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index aba6b789c969..484e5ec593bb 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -162,6 +162,12 @@ static inline int etm_readl_cp14(u32 off, unsigned int *val) { return 0; }
> static inline int etm_writel_cp14(u32 off, u32 val) { return 0; }
> #endif
>
> +#ifdef CONFIG_CORESIGHT_CTI
> +extern void cti_add_assoc_to_csdev(struct coresight_device *csdev);
> +#else
> +static inline void cti_add_assoc_to_csdev(struct coresight_device *csdev) {}
> +#endif
> +
> /*
> * Macros and inline functions to handle CoreSight UCI data and driver
> * private data in AMBA ID table entries, and extract data values.
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 1a5fdf2710ff..7657be009246 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -216,6 +216,31 @@ void coresight_disclaim_device(void __iomem *base)
> CS_LOCK(base);
> }
>
> +/* enable or disable an associated CTI device of the supplied CS device */
> +static int
> +coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
> +{
> + int ect_ret = 0;
> + struct coresight_device *ect_csdev = csdev->ect_dev;
> +
> + if (!ect_csdev)
> + return 0;
> +
> + if (enable) {
> + if (ect_ops(ect_csdev)->enable)
> + ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
> + } else {
> + if (ect_ops(ect_csdev)->disable)
> + ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
> + }
> +
> + /* output warning if ECT enable is preventing trace operation */
> + if (ect_ret)
> + dev_info(&csdev->dev, "Associated ECT device (%s) %s failed\n",
> + dev_name(&ect_csdev->dev), enable ? "enable" : "disable");

Indentation problem - please replace with:

dev_info(&csdev->dev, "Associated ECT device (%s) %s failed\n",
dev_name(&ect_csdev->dev),
enable ? "enable" : "disable");

> + return ect_ret;
> +}
> +
> static int coresight_enable_sink(struct coresight_device *csdev,
> u32 mode, void *data)
> {
> @@ -228,11 +253,15 @@ static int coresight_enable_sink(struct coresight_device *csdev,
> if (!sink_ops(csdev)->enable)
> return -EINVAL;
>
> - ret = sink_ops(csdev)->enable(csdev, mode, data);
> + ret = coresight_control_assoc_ectdev(csdev, true);
> if (ret)
> return ret;
> + ret = sink_ops(csdev)->enable(csdev, mode, data);
> + if (ret) {
> + coresight_control_assoc_ectdev(csdev, false);
> + return ret;
> + }
> csdev->enable = true;
> -

Unneeded modification.

With the above changes:
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> return 0;
> }
>
> @@ -246,6 +275,7 @@ static void coresight_disable_sink(struct coresight_device *csdev)
> ret = sink_ops(csdev)->disable(csdev);
> if (ret)
> return;
> + coresight_control_assoc_ectdev(csdev, false);
> csdev->enable = false;
> }
>
> @@ -269,8 +299,15 @@ static int coresight_enable_link(struct coresight_device *csdev,
> if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && outport < 0)
> return outport;
>
> - if (link_ops(csdev)->enable)
> - ret = link_ops(csdev)->enable(csdev, inport, outport);
> + if (link_ops(csdev)->enable) {
> + ret = coresight_control_assoc_ectdev(csdev, true);
> + if (!ret) {
> + ret = link_ops(csdev)->enable(csdev, inport, outport);
> + if (ret)
> + coresight_control_assoc_ectdev(csdev, false);
> + }
> + }
> +
> if (!ret)
> csdev->enable = true;
>
> @@ -300,8 +337,10 @@ static void coresight_disable_link(struct coresight_device *csdev,
> nr_conns = 1;
> }
>
> - if (link_ops(csdev)->disable)
> + if (link_ops(csdev)->disable) {
> link_ops(csdev)->disable(csdev, inport, outport);
> + coresight_control_assoc_ectdev(csdev, false);
> + }
>
> for (i = 0; i < nr_conns; i++)
> if (atomic_read(&csdev->refcnt[i]) != 0)
> @@ -322,9 +361,14 @@ static int coresight_enable_source(struct coresight_device *csdev, u32 mode)
>
> if (!csdev->enable) {
> if (source_ops(csdev)->enable) {
> - ret = source_ops(csdev)->enable(csdev, NULL, mode);
> + ret = coresight_control_assoc_ectdev(csdev, true);
> if (ret)
> return ret;
> + ret = source_ops(csdev)->enable(csdev, NULL, mode);
> + if (ret) {
> + coresight_control_assoc_ectdev(csdev, false);
> + return ret;
> + };
> }
> csdev->enable = true;
> }
> @@ -347,6 +391,7 @@ static bool coresight_disable_source(struct coresight_device *csdev)
> if (atomic_dec_return(csdev->refcnt) == 0) {
> if (source_ops(csdev)->disable)
> source_ops(csdev)->disable(csdev, NULL);
> + coresight_control_assoc_ectdev(csdev, false);
> csdev->enable = false;
> }
> return !csdev->enable;
> @@ -1252,6 +1297,7 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
>
> coresight_fixup_device_conns(csdev);
> coresight_fixup_orphan_conns(csdev);
> + cti_add_assoc_to_csdev(csdev);
>
> mutex_unlock(&coresight_mutex);
>
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index b3e582d96a34..b5dc9baf0c58 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -163,6 +163,8 @@ struct coresight_connection {
> * activated but not yet enabled. Enabling for a _sink_
> * appens when a source has been selected for that it.
> * @ea: Device attribute for sink representation under PMU directory.
> + * @ect_dev: Associated cross trigger device. Not part of the trace data
> + * path or connections.
> */
> struct coresight_device {
> struct coresight_platform_data *pdata;
> @@ -176,6 +178,8 @@ struct coresight_device {
> /* sink specific fields */
> bool activated; /* true only if a sink is part of a path */
> struct dev_ext_attribute *ea;
> + /* cross trigger handling */
> + struct coresight_device *ect_dev;
> };
>
> /*
> @@ -341,5 +345,6 @@ static inline bool coresight_loses_context_with_cpu(struct device *dev)
> extern int coresight_get_cpu(struct device *dev);
>
> struct coresight_platform_data *coresight_get_platform_data(struct device *dev);
> +extern const char *coresight_get_fwnode_name(struct device *dev);
>
> #endif
> --
> 2.17.1