Hi Mathieu,
On Fri, 14 Feb 2020 at 22:31, Mathieu Poirier
<mathieu.poirier@xxxxxxxxxx> wrote:
>
> Hi Mike,
>
> On Tue, Feb 11, 2020 at 10:58:06AM +0000, Mike Leach wrote:
> > From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> >
> > Coresight device connections are a bit complicated and is not
> > exposed currently to the user. One has to look at the platform
> > descriptions (DT bindings or ACPI bindings) to make an understanding.
> > Given the new naming scheme, it will be helpful to have this information
> > to choose the appropriate devices for tracing. This patch exposes
> > the device connections via links in the sysfs directories.
> >
> > e.g, for a connection devA[OutputPort_X] -> devB[InputPort_Y]
> > is represented as two symlinks:
> >
> > /sys/bus/coresight/.../devA/out:X -> /sys/bus/coresight/.../devB
> > /sys/bus/coresight/.../devB/in:Y -> /sys/bus/coresight/.../devA
> >
> > Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> >
> > Revised to use the generic sysfs links functions & link structures.
> > Provides a connections sysfs group to hold the links.
> >
> > Co-developed-by: Mike Leach <mike.leach@xxxxxxxxxx>
> > Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
>
> Because this patch is "From:" Suzuki, this should be:
>
> Co-developed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
>
if I do the above then checkpatch.pl:-
WARNING: Co-developed-by: should not be used to attribute nominal
patch author 'Suzuki K Poulose <suzuki.poulose@xxxxxxx>'
#25:
Co-developed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
WARNING: Co-developed-by and Signed-off-by: name/email do not match
#25:
Co-developed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Mike Leach <mike.leach@xxxxxxxxxx>
Regards
Mike
> You can expand on Suzuki's contribution or the modifications you've done to it
> in the changelog.
>
> With the above:
>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
>
> > ---
> > drivers/hwtracing/coresight/coresight-priv.h | 5 ++
> > drivers/hwtra cing/coresight/coresight-sysfs.c | 80 +++++++++++++++++++
> > drivers/hwtracing/coresight/coresight.c | 46 ++++++++---
> > include/linux/coresight.h | 2 +
> > 4 files changed, 121 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> > index a4a658d46045..5a36f0f50899 100644
> > --- a/drivers/hwtracing/coresight/coresight-priv.h
> > +++ b/drivers/hwtracing/coresight/coresight-priv.h
> > @@ -157,6 +157,11 @@ int coresight_add_sysfs_link(struct coresight_sysfs_link *info);
> > void coresight_remove_sysfs_link(struct coresight_sysfs_link *info);
> > int coresight_create_conns_sysfs_group(struct coresight_device *csdev);
> > void coresight_remove_conns_sysfs_group(struct coresight_device *csdev);
> > +int coresight_make_links(struct coresight_device *orig,
> > + struct coresight_connection *conn,
> > + struct coresight_device *target);
> > +void coresight_remove_links(struct coresight_device *orig,
> > + struct coresight_connection *conn);
> >
> > #ifdef CONFIG_CORESIGHT_SOURCE_ETM3X
> > extern int etm_readl_cp14(u32 off, unsigned int *val);
> > diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
> > index 17d565941e5e..0f18332b9f19 100644
> > --- a/drivers/hwtracing/coresight/coresight-sysfs.c
> > +++ b/drivers/hwtracing/coresight/coresight-sysfs.c
> > @@ -122,3 +122,83 @@ void coresight_remove_sysfs_link(struct coresight_sysfs_link *info)
> > info->orig->nr_links--;
> > info->target->nr_links--;
> > }
> > +
> > +/*
> > + * coresight_make_links: Make a link for a connection from a @orig
> > + * device to @target, represented by @conn.
> > + *
> > + * e.g, for devOrig[output_X] -> devTarget[input_Y] is represented
> > + * as two symbolic links :
> > + *
> > + * /sys/.../devOrig/out:X -> /sys/.../devTarget/
> > + * /sys/.../devTarget/in:Y -> /sys/.../devOrig/
> > + *
> > + * The link names are allocated for a device where it appears. i.e, the
> > + * "out" link on the master and "in" link on the slave device.
> > + * The link info is stored in the connection record for avoiding
> > + * the reconstruction of names for removal.
> > + */
> > +int coresight_make_links(struct coresight_device *orig,
> > + struct coresight_connection *conn,
> > + struct coresight_device *target)
> > +{
> > + int ret = -ENOMEM;
> > + char *outs = NULL, *ins = NULL;
> > + struct coresight_sysfs_link *link = NULL;
> > +
> > + do {
> > + outs = devm_kasprintf(&orig->dev, GFP_KERNEL,
> > + "out:%d", conn->outport);
> > + if (!outs)
> > + break;
> > + ins = devm_kasprintf(&target->dev, GFP_KERNEL,
> > + "in:%d", conn->child_port);
> > + if (!ins)
> > + break;
> > + link = devm_kzalloc(&orig->dev,
> > + sizeof(struct coresight_sysfs_link),
> > + GFP_KERNEL);
> > + if (!link)
> > + break;
> > +
> > + link->orig = orig;
> > + link->target = target;
> > + link->orig_name = outs;
> > + link->target_name = ins;
> > +
> > + ret = coresight_add_sysfs_link(link);
> > + if (ret)
> > + break;
> > +
> > + conn->link = link;
> > +
> > + /*
> > + * Install the device connection. This also indicates that
> > + * the links are operational on both ends.
> > + */
> > + conn->child_dev = target;
> > + return 0;
> > + } while (0);
> > +
> > + return ret;
> > +}
> > +
> > +/*
> > + * coresight_remove_links: Remove the sysfs links for a given connection @conn,
> > + * from @orig device to @target device. See coresight_make_links() for more
> > + * details.
> > + */
> > +void coresight_remove_links(struct coresight_device *orig,
> > + struct coresight_connection *conn)
> > +{
> > + if (!orig || !conn->link)
> > + return;
> > +
> > + coresight_remove_sysfs_link(conn->link);
> > +
> > + devm_kfree(&conn->child_dev->dev, conn->link->target_name);
> > + devm_kfree(&orig->dev, conn->link->orig_name);
> > + devm_kfree(&orig->dev, conn->link);
> > + conn->link = NULL;
> > + conn->child_dev = NULL;
> > +}
> > diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> > index 07f66a3968f1..4f10cfa9dc18 100644
> > --- a/drivers/hwtracing/coresight/coresight.c
> > +++ b/drivers/hwtracing/coresight/coresight.c
> > @@ -1031,7 +1031,7 @@ static void coresight_device_release(struct device *dev)
> >
> > static int coresight_orphan_match(struct device *dev, void *data)
> > {
> > - int i;
> > + int i, ret = 0;
> > bool still_orphan = false;
> > struct coresight_device *csdev, *i_csdev;
> > struct coresight_connection *conn;
> > @@ -1056,19 +1056,23 @@ static int coresight_orphan_match(struct device *dev, void *data)
> > /* We have found at least one orphan connection */
> > if (conn->child_dev == NULL) {
> > /* Does it match this newly added device? */
> > - if (conn->child_fwnode == csdev->dev.fwnode)
> > - conn->child_dev = csdev;
> > - else
> > + if (conn->child_fwnode == csdev->dev.fwnode) {
> > + ret = coresight_make_links(i_csdev,
> > + conn, csdev);
> > + if (ret)
> > + return ret;
> > + } else {
> > /* This component still has an orphan */
> > still_orphan = true;
> > + }
> > }
> > }
> >
> > i_csdev->orphan = still_orphan;
> >
> > /*
> > - * Returning '0' ensures that all known component on the
> > - * bus will be checked.
> > + * Returning '0' in case we didn't encounter any error,
> > + * ensures that all known component on the bus will be checked.
> > */
> > return 0;
> > }
> > @@ -1082,15 +1086,21 @@ static int coresight_fixup_orphan_conns(struct coresight_device *csdev)
> >
> > static int coresight_fixup_device_conns(struct coresight_device *csdev)
> > {
> > - int i;
> > + int i, ret = 0;
> >
> > for (i = 0; i < csdev->pdata->nr_outport; i++) {
> > struct coresight_connection *conn = &csdev->pdata->conns[i];
> >
> > conn->child_dev =
> > coresight_find_csdev_by_fwnode(conn->child_fwnode);
> > - if (!conn->child_dev)
> > + if (conn->child_dev) {
> > + ret = coresight_make_links(csdev, conn,
> > + conn->child_dev);
> > + if (ret)
> > + break;
> > + } else {
> > csdev->orphan = true;
> > + }
> > }
> >
> > return 0;
> > @@ -1121,7 +1131,7 @@ static int coresight_remove_match(struct device *dev, void *data)
> >
> > if (csdev->dev.fwnode == conn->child_fwnode) {
> > iterator->orphan = true;
> > - conn->child_dev = NULL;
> > + coresight_remove_links(iterator, conn);
> > /*
> > * Drop the reference to the handle for the remote
> > * device acquired in parsing the connections from
> > @@ -1215,13 +1225,23 @@ void coresight_release_platform_data(struct coresight_device *csdev,
> > struct coresight_platform_data *pdata)
> > {
> > int i;
> > + struct coresight_connection *conns = pdata->conns;
> >
> > for (i = 0; i < pdata->nr_outport; i++) {
> > - if (pdata->conns[i].child_fwnode) {
> > - fwnode_handle_put(pdata->conns[i].child_fwnode);
> > + /* If we have made the links, remove them now */
> > + if (csdev && conns[i].child_dev)
> > + coresight_remove_links(csdev, &conns[i]);
> > + /*
> > + * Drop the refcount and clear the handle as this device
> > + * is going away
> > + */
> > + if (conns[i].child_fwnode) {
> > + fwnode_handle_put(conns[i].child_fwnode);
> > pdata->conns[i].child_fwnode = NULL;
> > }
> > }
> > + if (csdev)
> > + coresight_remove_conns_sysfs_group(csdev);
> > }
> >
> > struct coresight_device *coresight_register(struct coresight_desc *desc)
> > @@ -1303,7 +1323,9 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
> >
> > mutex_lock(&coresight_mutex);
> >
> > - ret = coresight_fixup_device_conns(csdev);
> > + ret = coresight_create_conns_sysfs_group(csdev);
> > + if (!ret)
> > + ret = coresight_fixup_device_conns(csdev);
> > if (!ret)
> > ret = coresight_fixup_orphan_conns(csdev);
> > if (!ret)
> > diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> > index a2ec25e02ca9..ccd17304d7bd 100644
> > --- a/include/linux/coresight.h
> > +++ b/include/linux/coresight.h
> > @@ -140,12 +140,14 @@ struct coresight_desc {
> > * @chid_fwnode: remote component's fwnode handle.
> > * @child_dev: a @coresight_device representation of the component
> > connected to @outport.
> > + * @link: Representation of the connection as a sysfs link.
> > */
> > struct coresight_connection {
> > int outport;
> > int child_port;
> > struct fwnode_handle *child_fwnode;
> > struct coresight_device *child_dev;
> > + struct coresight_sysfs_link *link;
> > };
> >
> > /**
> > --
> > 2.17.1
> >
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
