[PATCH v4 13/13] coresight: Fix CTI module refcount leak by making it a helper device

The CTI module has some hard coded refcounting code that has a leak. For example running perf and then trying to unload it fails:

perf record -e cs_etm// -a -- ls rmmod coresight_cti

rmmod: ERROR: Module coresight_cti is in use

The coresight core already handles references of devices in use, so by making CTI a normal helper device, we get working refcounting for free.

Signed-off-by: James Clark james.clark@arm.com --- drivers/hwtracing/coresight/coresight-core.c | 106 ++++++------------ .../hwtracing/coresight/coresight-cti-core.c | 52 +++++---- .../hwtracing/coresight/coresight-cti-sysfs.c | 4 +- drivers/hwtracing/coresight/coresight-cti.h | 4 +- drivers/hwtracing/coresight/coresight-priv.h | 4 +- drivers/hwtracing/coresight/coresight-sysfs.c | 4 + include/linux/coresight.h | 30 +---- 7 files changed, 77 insertions(+), 127 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 16689fe4ba98..12cfca3712a0 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -236,60 +236,46 @@ void coresight_disclaim_device(struct coresight_device *csdev) } EXPORT_SYMBOL_GPL(coresight_disclaim_device);

-/* enable or disable an associated CTI device of the supplied CS device */ -static int -coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable) +/* + * Add a helper as an output device. This function takes the @coresight_mutex + * because it's assumed that it's called from the helper device, outside of the + * core code where the mutex would already be held. Don't add new calls to this + * from inside the core code, instead try to add the new helper to the DT and + * ACPI where it will be picked up and linked automatically. + */ +void coresight_add_helper(struct coresight_device *csdev, + struct coresight_device *helper) { - int ect_ret = 0; - struct coresight_device *ect_csdev = csdev->ect_dev; - struct module *mod; + int i; + struct coresight_connection conn = {}; + struct coresight_connection *new_conn;

- if (!ect_csdev) - return 0; - if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable)) - return 0; + lockdep_assert_not_held(&coresight_mutex); + might_sleep(); + mutex_lock(&coresight_mutex); + conn.dest_fwnode = fwnode_handle_get(dev_fwnode(&helper->dev)); + conn.dest_dev = helper; + conn.dest_port = conn.src_port = -1; + conn.src_dev = csdev;

- mod = ect_csdev->dev.parent->driver->owner; - if (enable) { - if (try_module_get(mod)) { - ect_ret = ect_ops(ect_csdev)->enable(ect_csdev); - if (ect_ret) { - module_put(mod); - } else { - get_device(ect_csdev->dev.parent); - csdev->ect_enabled = true; - } - } else - ect_ret = -ENODEV; - } else { - if (csdev->ect_enabled) { - ect_ret = ect_ops(ect_csdev)->disable(ect_csdev); - put_device(ect_csdev->dev.parent); - module_put(mod); - csdev->ect_enabled = false; - } - } + /* + * Check for duplicates because this is called every time a helper + * device is re-loaded. Existing connections will get re-linked + * automatically. + */ + for (i = 0; i < csdev->pdata->nr_outconns; ++i) + if (csdev->pdata->out_conns[i]->dest_fwnode == conn.dest_fwnode) + goto unlock;

- /* 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; -} + new_conn = + coresight_add_out_conn(csdev->dev.parent, csdev->pdata, &conn); + if (!IS_ERR(new_conn)) + coresight_add_in_conn(new_conn);

-/* - * 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; +unlock: mutex_unlock(&coresight_mutex); } -EXPORT_SYMBOL_GPL(coresight_set_assoc_ectdev_mutex); +EXPORT_SYMBOL_GPL(coresight_add_helper);

static int coresight_enable_sink(struct coresight_device *csdev, enum cs_mode mode, void *data) @@ -303,12 +289,8 @@ static int coresight_enable_sink(struct coresight_device *csdev, if (!sink_ops(csdev)->enable) return -EINVAL;

- 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; @@ -326,7 +308,6 @@ 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; }

@@ -351,17 +332,11 @@ static int coresight_enable_link(struct coresight_device *csdev, return PTR_ERR(outconn);

if (link_ops(csdev)->enable) { - ret = coresight_control_assoc_ectdev(csdev, true); - if (!ret) { - ret = link_ops(csdev)->enable(csdev, inconn, outconn); - if (ret) - coresight_control_assoc_ectdev(csdev, false); - } + ret = link_ops(csdev)->enable(csdev, inconn, outconn); + if (!ret) + csdev->enable = true; }

- if (!ret) - csdev->enable = true; - return ret; }

@@ -382,7 +357,6 @@ static void coresight_disable_link(struct coresight_device *csdev,

if (link_ops(csdev)->disable) { link_ops(csdev)->disable(csdev, inconn, outconn); - coresight_control_assoc_ectdev(csdev, false); }

if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) { @@ -410,14 +384,9 @@ int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,

if (!csdev->enable) { if (source_ops(csdev)->enable) { - ret = coresight_control_assoc_ectdev(csdev, true); - if (ret) - return ret; ret = source_ops(csdev)->enable(csdev, data, mode); - if (ret) { - coresight_control_assoc_ectdev(csdev, false); + if (ret) return ret; - } } csdev->enable = true; } @@ -488,7 +457,6 @@ bool coresight_disable_source(struct coresight_device *csdev, void *data) if (atomic_dec_return(&csdev->refcnt) == 0) { if (source_ops(csdev)->disable) source_ops(csdev)->disable(csdev, data); - coresight_control_assoc_ectdev(csdev, false); coresight_disable_helpers(csdev); csdev->enable = false; } diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c index 277c890a1f1f..7023ff70cc28 100644 --- a/drivers/hwtracing/coresight/coresight-cti-core.c +++ b/drivers/hwtracing/coresight/coresight-cti-core.c @@ -555,7 +555,10 @@ static void cti_add_assoc_to_csdev(struct coresight_device *csdev) mutex_lock(&ect_mutex);

/* exit if current is an ECT device.*/ - if ((csdev->type == CORESIGHT_DEV_TYPE_ECT) || list_empty(&ect_net)) + if ((csdev->type == CORESIGHT_DEV_TYPE_HELPER && + csdev->subtype.helper_subtype == + CORESIGHT_DEV_SUBTYPE_HELPER_ECT_CTI) || + list_empty(&ect_net)) goto cti_add_done;

/* if we didn't find the csdev previously we used the fwnode name */ @@ -571,8 +574,7 @@ static void cti_add_assoc_to_csdev(struct coresight_device *csdev) * if we found a matching csdev then update the ECT * association pointer for the device with this CTI. */ - coresight_set_assoc_ectdev_mutex(csdev, - ect_item->csdev); + coresight_add_helper(csdev, ect_item->csdev); break; } } @@ -582,26 +584,30 @@ static void cti_add_assoc_to_csdev(struct coresight_device *csdev)

/* * Removing the associated devices is easier. - * A CTI will not have a value for csdev->ect_dev. */ static void cti_remove_assoc_from_csdev(struct coresight_device *csdev) { struct cti_drvdata *ctidrv; struct cti_trig_con *tc; struct cti_device *ctidev; + union coresight_dev_subtype cti_subtype = { + .helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_ECT_CTI + }; + struct coresight_device *cti_csdev = coresight_find_output_type( + csdev->pdata, CORESIGHT_DEV_TYPE_HELPER, cti_subtype); + + if (!cti_csdev) + return;

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) { - cti_remove_sysfs_link(ctidrv, tc); - tc->con_dev = NULL; - break; - } + ctidrv = csdev_to_cti_drvdata(cti_csdev); + ctidev = &ctidrv->ctidev; + list_for_each_entry(tc, &ctidev->trig_cons, node) { + if (tc->con_dev == csdev) { + cti_remove_sysfs_link(ctidrv, tc); + tc->con_dev = NULL; + break; } - csdev->ect_dev = NULL; } mutex_unlock(&ect_mutex); } @@ -630,8 +636,8 @@ static void cti_update_conn_xrefs(struct cti_drvdata *drvdata) /* if we can set the sysfs link */ if (cti_add_sysfs_link(drvdata, tc)) /* set the CTI/csdev association */ - coresight_set_assoc_ectdev_mutex(tc->con_dev, - drvdata->csdev); + coresight_add_helper(tc->con_dev, + drvdata->csdev); else /* otherwise remove reference from CTI */ tc->con_dev = NULL; @@ -646,8 +652,6 @@ static void cti_remove_conn_xrefs(struct cti_drvdata *drvdata)

list_for_each_entry(tc, &ctidev->trig_cons, node) { if (tc->con_dev) { - coresight_set_assoc_ectdev_mutex(tc->con_dev, - NULL); cti_remove_sysfs_link(drvdata, tc); tc->con_dev = NULL; } @@ -795,27 +799,27 @@ static void cti_pm_release(struct cti_drvdata *drvdata) }

/** cti ect operations **/ -int cti_enable(struct coresight_device *csdev) +int cti_enable(struct coresight_device *csdev, enum cs_mode mode, void *data) { struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);

return cti_enable_hw(drvdata); }

-int cti_disable(struct coresight_device *csdev) +int cti_disable(struct coresight_device *csdev, void *data) { struct cti_drvdata *drvdata = csdev_to_cti_drvdata(csdev);

return cti_disable_hw(drvdata); }

-static const struct coresight_ops_ect cti_ops_ect = { +static const struct coresight_ops_helper cti_ops_ect = { .enable = cti_enable, .disable = cti_disable, };

static const struct coresight_ops cti_ops = { - .ect_ops = &cti_ops_ect, + .helper_ops = &cti_ops_ect, };

/* @@ -922,8 +926,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)

/* set up coresight component description */ cti_desc.pdata = pdata; - cti_desc.type = CORESIGHT_DEV_TYPE_ECT; - cti_desc.subtype.ect_subtype = CORESIGHT_DEV_SUBTYPE_ECT_CTI; + cti_desc.type = CORESIGHT_DEV_TYPE_HELPER; + cti_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_ECT_CTI; cti_desc.ops = &cti_ops; cti_desc.groups = drvdata->ctidev.con_groups; cti_desc.dev = dev; diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c index e528cff9d4e2..d25dd2737b49 100644 --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c @@ -112,11 +112,11 @@ static ssize_t enable_store(struct device *dev, ret = pm_runtime_resume_and_get(dev->parent); if (ret) return ret; - ret = cti_enable(drvdata->csdev); + ret = cti_enable(drvdata->csdev, CS_MODE_SYSFS, NULL); if (ret) pm_runtime_put(dev->parent); } else { - ret = cti_disable(drvdata->csdev); + ret = cti_disable(drvdata->csdev, NULL); if (!ret) pm_runtime_put(dev->parent); } diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h index 8b106b13a244..cb9ee616d01f 100644 --- a/drivers/hwtracing/coresight/coresight-cti.h +++ b/drivers/hwtracing/coresight/coresight-cti.h @@ -215,8 +215,8 @@ int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata, const char *assoc_dev_name); struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs, int out_sigs); -int cti_enable(struct coresight_device *csdev); -int cti_disable(struct coresight_device *csdev); +int cti_enable(struct coresight_device *csdev, enum cs_mode mode, void *data); +int cti_disable(struct coresight_device *csdev, void *data); void cti_write_all_hw_regs(struct cti_drvdata *drvdata); void cti_write_intack(struct device *dev, u32 ackval); void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value); diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 5575014f73e0..1801ff4e467b 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -211,8 +211,8 @@ void coresight_release_platform_data(struct coresight_device *csdev, 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); +void coresight_add_helper(struct coresight_device *csdev, + struct coresight_device *helper);

void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev); struct coresight_device *coresight_get_percpu_sink(int cpu); diff --git a/drivers/hwtracing/coresight/coresight-sysfs.c b/drivers/hwtracing/coresight/coresight-sysfs.c index 464ba5e1343b..dd78e9fcfc4d 100644 --- a/drivers/hwtracing/coresight/coresight-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-sysfs.c @@ -148,6 +148,10 @@ int coresight_make_links(struct coresight_device *orig, char *outs = NULL, *ins = NULL; struct coresight_sysfs_link *link = NULL;

+ /* Helper devices aren't shown in sysfs */ + if (conn->dest_port == -1 && conn->src_port == -1) + return 0; + do { outs = devm_kasprintf(&orig->dev, GFP_KERNEL, "out:%d", conn->src_port); diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 61dfbab5fa98..225a5fa71baf 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -40,8 +40,7 @@ enum coresight_dev_type { CORESIGHT_DEV_TYPE_LINK, CORESIGHT_DEV_TYPE_LINKSINK, CORESIGHT_DEV_TYPE_SOURCE, - CORESIGHT_DEV_TYPE_HELPER, - CORESIGHT_DEV_TYPE_ECT, + CORESIGHT_DEV_TYPE_HELPER };

enum coresight_dev_subtype_sink { @@ -66,12 +65,7 @@ enum coresight_dev_subtype_source {

enum coresight_dev_subtype_helper { CORESIGHT_DEV_SUBTYPE_HELPER_CATU, -}; - -/* Embedded Cross Trigger (ECT) sub-types */ -enum coresight_dev_subtype_ect { - CORESIGHT_DEV_SUBTYPE_ECT_NONE, - CORESIGHT_DEV_SUBTYPE_ECT_CTI, + CORESIGHT_DEV_SUBTYPE_HELPER_ECT_CTI };

/** @@ -84,8 +78,6 @@ enum coresight_dev_subtype_ect { * by @coresight_dev_subtype_source. * @helper_subtype: type of helper this component is, as defined * by @coresight_dev_subtype_helper. - * @ect_subtype: type of cross trigger this component is, as - * defined by @coresight_dev_subtype_ect */ union coresight_dev_subtype { /* We have some devices which acts as LINK and SINK */ @@ -95,7 +87,6 @@ union coresight_dev_subtype { }; enum coresight_dev_subtype_source source_subtype; enum coresight_dev_subtype_helper helper_subtype; - enum coresight_dev_subtype_ect ect_subtype; };

/** @@ -239,8 +230,6 @@ struct coresight_sysfs_link { * from source to that sink. * @ea: Device attribute for sink representation under PMU directory. * @def_sink: cached reference to default sink found for this device. - * @ect_dev: Associated cross trigger device. Not part of the trace data - * path or connections. * @nr_links: number of sysfs links created to other components from this * device. These will appear in the "connections" group. * @has_conns_grp: Have added a "connections" group for sysfs links. @@ -263,12 +252,9 @@ struct coresight_device { bool activated; /* true only if a sink is part of a path */ struct dev_ext_attribute *ea; struct coresight_device *def_sink; - /* cross trigger handling */ - struct coresight_device *ect_dev; /* sysfs links between components */ int nr_links; bool has_conns_grp; - bool ect_enabled; /* true only if associated ect device is enabled */ /* system configuration and feature lists */ struct list_head feature_csdev_list; struct list_head config_csdev_list; @@ -380,23 +366,11 @@ struct coresight_ops_helper { int (*disable)(struct coresight_device *csdev, void *data); };

-/** - * struct coresight_ops_ect - Ops for an embedded cross trigger device - * - * @enable : Enable the device - * @disable : Disable the device - */ -struct coresight_ops_ect { - int (*enable)(struct coresight_device *csdev); - int (*disable)(struct coresight_device *csdev); -}; - struct coresight_ops { const struct coresight_ops_sink *sink_ops; const struct coresight_ops_link *link_ops; const struct coresight_ops_source *source_ops; const struct coresight_ops_helper *helper_ops; - const struct coresight_ops_ect *ect_ops; };

#if IS_ENABLED(CONFIG_CORESIGHT)