Re: [PATCH v9 08/15] coresight: cti: Enable CTI associated with devices.

Mathieu Poirier
2020-02-17T23:12:34Z

Hi Suzuki,

As far as I can tell Mike made the modifications you have requested. Please
have a look to make sure it is the case before I add this to my next tree.

Thanks,
Mathieu

On Mon, Feb 10, 2020 at 09:39:17PM +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>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-cti.c | 129 +++++++++++++++++++
> drivers/hwtracing/coresight/coresight-cti.h | 1 +
> drivers/hwtracing/coresight/coresight-priv.h | 12 ++
> drivers/hwtracing/coresight/coresight.c | 71 +++++++++-
> include/linux/coresight.h | 4 +
> 5 files changed, 212 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
> index 77c2af247917..c4494923d030 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.c
> +++ b/drivers/hwtracing/coresight/coresight-cti.c
> @@ -4,6 +4,7 @@
> * Author: Mike Leach <mike.leach@linaro.org>
> */
>
> +#include <linux/property.h>
> #include "coresight-cti.h"
>
> /**
> @@ -440,6 +441,131 @@ 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, set trig con association pointer
> + * and return found.
> + */
> +static bool
> +cti_match_fixup_csdev(struct cti_device *ctidev, const char *node_name,
> + struct coresight_device *csdev)
> +{
> + struct cti_trig_con *tc;
> + const char *csdev_name;
> +
> + list_for_each_entry(tc, &ctidev->trig_cons, node) {
> + if (tc->con_dev_name) {
> + if (!strcmp(node_name, tc->con_dev_name)) {
> + /* match: so swap in csdev name & dev */
> + csdev_name = dev_name(&csdev->dev);
> + tc->con_dev_name =
> + devm_kstrdup(&csdev->dev, csdev_name,
> + GFP_KERNEL);
> + tc->con_dev = csdev;
> + 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.
> + * (called from coresight_register() with coresight_mutex locked).
> + */
> +void cti_add_assoc_to_csdev(struct coresight_device *csdev)
> +{
> + struct cti_drvdata *ect_item;
> + struct cti_device *ctidev;
> + const char *node_name = NULL;
> +
> + /* 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 = cti_plat_get_node_name(dev_fwnode(csdev->dev.parent));
> + if (!node_name)
> + goto cti_add_done;
> +
> + /* for each CTI in list... */
> + list_for_each_entry(ect_item, &ect_net, node) {
> + ctidev = &ect_item->ctidev;
> + if (cti_match_fixup_csdev(ctidev, node_name, csdev)) {
> + /*
> + * if we found a matching csdev then update the ECT
> + * association pointer for the device with this CTI.
> + */
> + csdev->ect_dev = ect_item->csdev;
> + break;
> + }
> + }
> +cti_add_done:
> + mutex_unlock(&ect_mutex);
> +}
> +EXPORT_SYMBOL_GPL(cti_add_assoc_to_csdev);
> +
> +/*
> + * Removing the associated devices is easier.
> + * A CTI will not have a value for csdev->ect_dev.
> + */
> +void cti_remove_assoc_from_csdev(struct coresight_device *csdev)
> +{
> + struct cti_drvdata *ctidrv;
> + struct cti_trig_con *tc;
> + struct cti_device *ctidev;
> +
> + mutex_lock(&ect_mutex);
> + if (csdev->ect_dev) {
> + ctidrv = csdev_to_cti_drvdata(csdev->ect_dev);
> + ctidev = &ctidrv->ctidev;
> + list_for_each_entry(tc, &ctidev->trig_cons, node) {
> + if (tc->con_dev == csdev->ect_dev) {
> + tc->con_dev = NULL;
> + break;
> + }
> + }
> + csdev->ect_dev = NULL;
> + }
> + mutex_unlock(&ect_mutex);
> +}
> +EXPORT_SYMBOL_GPL(cti_remove_assoc_from_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)
> + /* set tc->con_dev->ect_dev */
> + coresight_set_assoc_ectdev_mutex(tc->con_dev,
> + drvdata->csdev);
> + }
> +}
> +
> +static void cti_remove_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) {
> + coresight_set_assoc_ectdev_mutex(tc->con_dev,
> + NULL);
> + }
> + }
> +}
> +
> /** cti ect operations **/
> int cti_enable(struct coresight_device *csdev)
> {
> @@ -474,6 +600,7 @@ static void cti_device_release(struct device *dev)
> struct cti_drvdata *ect_item, *ect_tmp;
>
> mutex_lock(&ect_mutex);
> + cti_remove_conn_xrefs(drvdata);
>
> /* remove from the list */
> list_for_each_entry_safe(ect_item, ect_tmp, &ect_net, node) {
> @@ -565,6 +692,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
> /* add to list of CTI devices */
> mutex_lock(&ect_mutex);
> list_add(&drvdata->node, &ect_net);
> + /* set any cross references */
> + cti_update_conn_xrefs(drvdata);
> mutex_unlock(&ect_mutex);
>
> /* set up release chain */
> diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
> index 469a06a1bb78..578d7e9ac67e 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.h
> +++ b/drivers/hwtracing/coresight/coresight-cti.h
> @@ -216,6 +216,7 @@ int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
> u32 channel_idx);
> struct coresight_platform_data *
> coresight_cti_get_platform_data(struct device *dev);
> +const char *cti_plat_get_node_name(struct fwnode_handle *fwnode);
>
> /* cti powered and enabled */
> static inline bool cti_active(struct cti_config *cfg)
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 357ffef7b825..890f9a5c97c6 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -162,6 +162,16 @@ 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);
> +extern void cti_remove_assoc_from_csdev(struct coresight_device *csdev);
> +
> +#else
> +static inline void cti_add_assoc_to_csdev(struct coresight_device *csdev) {}
> +static inline void
> +cti_remove_assoc_from_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.
> @@ -204,5 +214,7 @@ static inline void *coresight_get_uci_data(const struct amba_id *id)
> void coresight_release_platform_data(struct coresight_platform_data *pdata);
> struct coresight_device *
> coresight_find_csdev_by_fwnode(struct fwnode_handle *r_fwnode);
> +void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev,
> + struct coresight_device *ect_csdev);
>
> #endif
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 39a5d9f7a395..c71553c09f8e 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -216,6 +216,44 @@ 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");
> + return ect_ret;
> +}
> +
> +/*
> + * Set the associated ect / cti device while holding the coresight_mutex
> + * to avoid a race with coresight_enable that may try to use this value.
> + */
> +void coresight_set_assoc_ectdev_mutex(struct coresight_device *csdev,
> + struct coresight_device *ect_csdev)
> +{
> + mutex_lock(&coresight_mutex);
> + csdev->ect_dev = ect_csdev;
> + mutex_unlock(&coresight_mutex);
> +}
> +
> static int coresight_enable_sink(struct coresight_device *csdev,
> u32 mode, void *data)
> {
> @@ -228,9 +266,14 @@ 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;
>
> return 0;
> @@ -246,6 +289,7 @@ 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 +313,15 @@ 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 +351,10 @@ 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 +375,14 @@ 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 +405,7 @@ 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;
> @@ -964,6 +1023,7 @@ static void coresight_device_release(struct device *dev)
> {
> struct coresight_device *csdev = to_coresight_device(dev);
>
> + cti_remove_assoc_from_csdev(csdev);
> fwnode_handle_put(csdev->dev.fwnode);
> kfree(csdev->refcnt);
> kfree(csdev);
> @@ -1246,6 +1306,7 @@ 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..193cc9dbf448 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;
> };
>
> /*
> --
> 2.17.1
>