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 6759f78733ab..82afeaf2ccc4 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; }; /**