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References: <20230404155121.1824126-1-james.clark@arm.com> <20230404155121.1824126-6-james.clark@arm.com>
In-Reply-To: <20230404155121.1824126-6-james.clark@arm.com>
From:   Mike Leach <mike.leach@linaro.org>
Date:   Wed, 12 Apr 2023 14:32:21 +0100
Message-ID: <CAJ9a7VhfYcrUm-wvsHzMBuFO5V=66G+cbv4AaJofLekQqfuFGw@mail.gmail.com>
Subject: Re: [PATCH v5 05/13] coresight: Rename connection members to make the
 direction explicit
To:     James Clark <james.clark@arm.com>
Cc:     coresight@lists.linaro.org, quic_jinlmao@quicinc.com,
        suzuki.poulose@arm.com,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
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Precedence: bulk

On Tue, 4 Apr 2023 at 16:52, James Clark <james.clark@arm.com> wrote:
>
> When input connections are added they will use the same connection
> object as the output so parent and child could be misinterpreted. Making
> the direction unambiguous in the names should improve readability.
>
> Signed-off-by: James Clark <james.clark@arm.com>
> ---
>  drivers/hwtracing/coresight/coresight-core.c  | 51 +++++++++----------
>  .../hwtracing/coresight/coresight-platform.c  | 30 +++++------
>  drivers/hwtracing/coresight/coresight-sysfs.c | 10 ++--
>  .../hwtracing/coresight/coresight-tmc-etr.c   |  2 +-
>  include/linux/coresight.h                     | 18 +++----
>  5 files changed, 55 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 0f6712a6fba3..f3dc320b374c 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -120,8 +120,8 @@ static int coresight_find_link_inport(struct coresight_device *csdev,
>
>         for (i = 0; i < parent->pdata->nr_outconns; i++) {
>                 conn = &parent->pdata->out_conns[i];
> -               if (conn->child_dev == csdev)
> -                       return conn->child_port;
> +               if (conn->dest_dev == csdev)
> +                       return conn->dest_port;
>         }
>
>         dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
> @@ -138,8 +138,8 @@ static int coresight_find_link_outport(struct coresight_device *csdev,
>
>         for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>                 conn = &csdev->pdata->out_conns[i];
> -               if (conn->child_dev == child)
> -                       return conn->outport;
> +               if (conn->dest_dev == child)
> +                       return conn->src_port;
>         }
>
>         dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
> @@ -606,7 +606,7 @@ coresight_find_enabled_sink(struct coresight_device *csdev)
>         for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>                 struct coresight_device *child_dev;
>
> -               child_dev = csdev->pdata->out_conns[i].child_dev;
> +               child_dev = csdev->pdata->out_conns[i].dest_dev;
>                 if (child_dev)
>                         sink = coresight_find_enabled_sink(child_dev);
>                 if (sink)
> @@ -722,7 +722,7 @@ static int coresight_grab_device(struct coresight_device *csdev)
>         for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>                 struct coresight_device *child;
>
> -               child = csdev->pdata->out_conns[i].child_dev;
> +               child = csdev->pdata->out_conns[i].dest_dev;
>                 if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
>                         if (!coresight_get_ref(child))
>                                 goto err;
> @@ -733,7 +733,7 @@ static int coresight_grab_device(struct coresight_device *csdev)
>         for (i--; i >= 0; i--) {
>                 struct coresight_device *child;
>
> -               child = csdev->pdata->out_conns[i].child_dev;
> +               child = csdev->pdata->out_conns[i].dest_dev;
>                 if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
>                         coresight_put_ref(child);
>         }
> @@ -752,7 +752,7 @@ static void coresight_drop_device(struct coresight_device *csdev)
>         for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>                 struct coresight_device *child;
>
> -               child = csdev->pdata->out_conns[i].child_dev;
> +               child = csdev->pdata->out_conns[i].dest_dev;
>                 if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
>                         coresight_put_ref(child);
>         }
> @@ -794,7 +794,7 @@ static int _coresight_build_path(struct coresight_device *csdev,
>         for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>                 struct coresight_device *child_dev;
>
> -               child_dev = csdev->pdata->out_conns[i].child_dev;
> +               child_dev = csdev->pdata->out_conns[i].dest_dev;
>                 if (child_dev &&
>                     _coresight_build_path(child_dev, sink, path) == 0) {
>                         found = true;
> @@ -964,7 +964,7 @@ coresight_find_sink(struct coresight_device *csdev, int *depth)
>                 struct coresight_device *child_dev, *sink = NULL;
>                 int child_depth = curr_depth;
>
> -               child_dev = csdev->pdata->out_conns[i].child_dev;
> +               child_dev = csdev->pdata->out_conns[i].dest_dev;
>                 if (child_dev)
>                         sink = coresight_find_sink(child_dev, &child_depth);
>
> @@ -1337,12 +1337,12 @@ static int coresight_orphan_match(struct device *dev, void *data)
>                 conn = &i_csdev->pdata->out_conns[i];
>
>                 /* Skip the port if FW doesn't describe it */
> -               if (!conn->child_fwnode)
> +               if (!conn->dest_fwnode)
>                         continue;
>                 /* We have found at least one orphan connection */
> -               if (conn->child_dev == NULL) {
> +               if (conn->dest_dev == NULL) {
>                         /* Does it match this newly added device? */
> -                       if (conn->child_fwnode == csdev->dev.fwnode) {
> +                       if (conn->dest_fwnode == csdev->dev.fwnode) {
>                                 ret = coresight_make_links(i_csdev,
>                                                            conn, csdev);
>                                 if (ret)
> @@ -1377,13 +1377,12 @@ static int coresight_fixup_device_conns(struct coresight_device *csdev)
>         for (i = 0; i < csdev->pdata->nr_outconns; i++) {
>                 struct coresight_connection *conn = &csdev->pdata->out_conns[i];
>
> -               if (!conn->child_fwnode)
> +               if (!conn->dest_fwnode)
>                         continue;
> -               conn->child_dev =
> -                       coresight_find_csdev_by_fwnode(conn->child_fwnode);
> -               if (conn->child_dev && conn->child_dev->has_conns_grp) {
> -                       ret = coresight_make_links(csdev, conn,
> -                                                  conn->child_dev);
> +               conn->dest_dev =
> +                       coresight_find_csdev_by_fwnode(conn->dest_fwnode);
> +               if (conn->dest_dev && conn->dest_dev->has_conns_grp) {
> +                       ret = coresight_make_links(csdev, conn, conn->dest_dev);
>                         if (ret)
>                                 break;
>                 } else {
> @@ -1414,14 +1413,14 @@ static int coresight_remove_match(struct device *dev, void *data)
>         for (i = 0; i < iterator->pdata->nr_outconns; i++) {
>                 conn = &iterator->pdata->out_conns[i];
>
> -               if (conn->child_dev == NULL || conn->child_fwnode == NULL)
> +               if (conn->dest_dev == NULL || conn->dest_fwnode == NULL)
>                         continue;
>
> -               if (csdev->dev.fwnode == conn->child_fwnode) {
> +               if (csdev->dev.fwnode == conn->dest_fwnode) {
>                         iterator->orphan = true;
>                         coresight_remove_links(iterator, conn);
>
> -                       conn->child_dev = NULL;
> +                       conn->dest_dev = NULL;
>                         /* No need to continue */
>                         break;
>                 }
> @@ -1547,15 +1546,15 @@ void coresight_release_platform_data(struct coresight_device *csdev,
>
>         for (i = 0; i < pdata->nr_outconns; i++) {
>                 /* If we have made the links, remove them now */
> -               if (csdev && conns[i].child_dev)
> +               if (csdev && conns[i].dest_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);
> -                       conns[i].child_fwnode = NULL;
> +               if (conns[i].dest_fwnode) {
> +                       fwnode_handle_put(conns[i].dest_fwnode);
> +                       conns[i].dest_fwnode = NULL;
>                 }
>         }
>         if (csdev)
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index ed865e0621a9..566cc99a2c34 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -252,13 +252,13 @@ static int of_coresight_parse_endpoint(struct device *dev,
>                 }
>
>                 conn = &pdata->out_conns[endpoint.port];
> -               if (conn->child_fwnode) {
> +               if (conn->dest_fwnode) {
>                         dev_warn(dev, "Duplicate output port %d\n",
>                                  endpoint.port);
>                         ret = -EINVAL;
>                         break;
>                 }
> -               conn->outport = endpoint.port;
> +               conn->src_port = endpoint.port;
>                 /*
>                  * Hold the refcount to the target device. This could be
>                  * released via:
> @@ -267,8 +267,8 @@ static int of_coresight_parse_endpoint(struct device *dev,
>                  * 2) While removing the target device via
>                  *    coresight_remove_match()
>                  */
> -               conn->child_fwnode = fwnode_handle_get(rdev_fwnode);
> -               conn->child_port = rendpoint.port;
> +               conn->dest_fwnode = fwnode_handle_get(rdev_fwnode);
> +               conn->dest_port = rendpoint.port;
>                 /* Connection record updated */
>         } while (0);
>
> @@ -649,8 +649,8 @@ static int acpi_coresight_parse_link(struct acpi_device *adev,
>
>         dir = fields[3].integer.value;
>         if (dir == ACPI_CORESIGHT_LINK_MASTER) {
> -               conn->outport = fields[0].integer.value;
> -               conn->child_port = fields[1].integer.value;
> +               conn->src_port = fields[0].integer.value;
> +               conn->dest_port = fields[1].integer.value;
>                 rdev = coresight_find_device_by_fwnode(&r_adev->fwnode);
>                 if (!rdev)
>                         return -EPROBE_DEFER;
> @@ -662,14 +662,14 @@ static int acpi_coresight_parse_link(struct acpi_device *adev,
>                  * 2) While removing the target device via
>                  *    coresight_remove_match().
>                  */
> -               conn->child_fwnode = fwnode_handle_get(&r_adev->fwnode);
> +               conn->dest_fwnode = fwnode_handle_get(&r_adev->fwnode);
>         } else if (dir == ACPI_CORESIGHT_LINK_SLAVE) {
>                 /*
>                  * We are only interested in the port number
>                  * for the input ports at this component.
>                  * Store the port number in child_port.
>                  */
> -               conn->child_port = fields[0].integer.value;
> +               conn->dest_port = fields[0].integer.value;
>         } else {
>                 /* Invalid direction */
>                 return -EINVAL;
> @@ -718,11 +718,11 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev,
>                         return dir;
>
>                 if (dir == ACPI_CORESIGHT_LINK_MASTER) {
> -                       if (ptr->outport >= pdata->nr_outconns)
> -                               pdata->nr_outconns = ptr->outport + 1;
> +                       if (ptr->src_port >= pdata->nr_outconns)
> +                               pdata->nr_outconns = ptr->src_port + 1;
>                         ptr++;
>                 } else {
> -                       WARN_ON(pdata->nr_inconns == ptr->child_port + 1);
> +                       WARN_ON(pdata->nr_inconns == ptr->dest_port + 1);
>                         /*
>                          * We do not track input port connections for a device.
>                          * However we need the highest port number described,
> @@ -730,8 +730,8 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev,
>                          * record for an output connection. Hence, do not move
>                          * the ptr for input connections
>                          */
> -                       if (ptr->child_port >= pdata->nr_inconns)
> -                               pdata->nr_inconns = ptr->child_port + 1;
> +                       if (ptr->dest_port >= pdata->nr_inconns)
> +                               pdata->nr_inconns = ptr->dest_port + 1;
>                 }
>         }
>
> @@ -741,10 +741,10 @@ static int acpi_coresight_parse_graph(struct acpi_device *adev,
>
>         /* Copy the connection information to the final location */
>         for (i = 0; conns + i < ptr; i++) {
> -               int port = conns[i].outport;
> +               int port = conns[i].src_port;
>
>                 /* Duplicate output port */
> -               WARN_ON(pdata->out_conns[port].child_fwnode);
> +               WARN_ON(pdata->out_conns[port].dest_fwnode);
>                 pdata->out_conns[port] = conns[i];
>         }
>
> diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c
> index 34d2a2d31d00..a4a8e8e642e8 100644
> --- a/drivers/hwtracing/coresight/coresight-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-sysfs.c
> @@ -150,11 +150,11 @@ int coresight_make_links(struct coresight_device *orig,
>
>         do {
>                 outs = devm_kasprintf(&orig->dev, GFP_KERNEL,
> -                                     "out:%d", conn->outport);
> +                                     "out:%d", conn->src_port);
>                 if (!outs)
>                         break;
>                 ins = devm_kasprintf(&target->dev, GFP_KERNEL,
> -                                    "in:%d", conn->child_port);
> +                                    "in:%d", conn->dest_port);
>                 if (!ins)
>                         break;
>                 link = devm_kzalloc(&orig->dev,
> @@ -178,7 +178,7 @@ int coresight_make_links(struct coresight_device *orig,
>                  * Install the device connection. This also indicates that
>                  * the links are operational on both ends.
>                  */
> -               conn->child_dev = target;
> +               conn->dest_dev = target;
>                 return 0;
>         } while (0);
>
> @@ -198,9 +198,9 @@ void coresight_remove_links(struct coresight_device *orig,
>
>         coresight_remove_sysfs_link(conn->link);
>
> -       devm_kfree(&conn->child_dev->dev, conn->link->target_name);
> +       devm_kfree(&conn->dest_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;
> +       conn->dest_dev = NULL;
>  }
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index 4711dfa7418c..61234cb8052a 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -782,7 +782,7 @@ tmc_etr_get_catu_device(struct tmc_drvdata *drvdata)
>                 return NULL;
>
>         for (i = 0; i < etr->pdata->nr_outconns; i++) {
> -               tmp = etr->pdata->out_conns[i].child_dev;
> +               tmp = etr->pdata->out_conns[i].dest_dev;
>                 if (tmp && coresight_is_catu_device(tmp))
>                         return tmp;
>         }
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index daf392fcb67a..b6f444804bf3 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -164,18 +164,18 @@ struct coresight_desc {
>
>  /**
>   * struct coresight_connection - representation of a single connection
> - * @outport:   a connection's output port number.
> - * @child_port:        remote component's port number @output is connected to.
> - * @chid_fwnode: remote component's fwnode handle.
> - * @child_dev: a @coresight_device representation of the component
> -               connected to @outport.
> + * @src_port:  a connection's output port number.
> + * @dest_port: destination's input port number @src_port is connected to.
> + * @dest_fwnode: destination component's fwnode handle.
> + * @dest_dev:  a @coresight_device representation of the component
> +               connected to @src_port. NULL until the device is created
>   * @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;
> +       int src_port;
> +       int dest_port;
> +       struct fwnode_handle *dest_fwnode;
> +       struct coresight_device *dest_dev;
>         struct coresight_sysfs_link *link;
>  };
>
> --
> 2.34.1
>

Reviewed-by: Mike Leach <mike.leach@linaro.org>

-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK