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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-11 20:54:28 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-11 20:54:28 +0200
commit7e724422a7e9dfc8229ba90ee95aaafb902a788b (patch)
treef24b9a9d15040948475ccde31425fff1332937cf /drivers/hwtracing
parent4682f21368352ce087e3a2f73e1e6d776c38f685 (diff)
parent4d45bc82df667ad9e9cb8361830e54fc1264e993 (diff)
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Merge tag 'coresight-next-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux into char-misc-next
Suzuki writes: CoreSight self-hosted tracing changes for v5.20. - Fixes LOCKDEP warnings on module unload with configfs - Conversion of DT bindings to DT schema - Branch broadcast support for perf cs_etm - Etm4x driver fixes for build failures with Clang and unrolled loops Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> * tag 'coresight-next-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux: coresight: etm4x: avoid build failure with unrolled loops Documentation: coresight: Expand branch broadcast documentation Documentation: coresight: Link config options to existing documentation Documentation: coresight: Turn numbered subsections into real subsections coresight: Add config flag to enable branch broadcast Documentation: coresight: Escape coresight bindings file wildcard dt-bindings: arm: Convert CoreSight CPU debug to DT schema dt-bindings: arm: Convert CoreSight bindings to DT schema dt-bindings: arm: Rename Coresight filenames to match compatible coresight: syscfg: Update load and unload operations coresight: configfs: Fix unload of configurations on module exit coresight: Clear the connection field properly
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-config.h2
-rw-r--r--drivers/hwtracing/coresight/coresight-core.c1
-rw-r--r--drivers/hwtracing/coresight/coresight-etm-perf.c2
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x-core.c14
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x.h3
-rw-r--r--drivers/hwtracing/coresight/coresight-syscfg.c295
-rw-r--r--drivers/hwtracing/coresight/coresight-syscfg.h13
7 files changed, 277 insertions, 53 deletions
diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h
index 2e1670523461..6ba013975741 100644
--- a/drivers/hwtracing/coresight/coresight-config.h
+++ b/drivers/hwtracing/coresight/coresight-config.h
@@ -134,6 +134,7 @@ struct cscfg_feature_desc {
* @active_cnt: ref count for activate on this configuration.
* @load_owner: handle to load owner for dynamic load and unload of configs.
* @fs_group: reference to configfs group for dynamic unload.
+ * @available: config can be activated - multi-stage load sets true on completion.
*/
struct cscfg_config_desc {
const char *name;
@@ -148,6 +149,7 @@ struct cscfg_config_desc {
atomic_t active_cnt;
void *load_owner;
struct config_group *fs_group;
+ bool available;
};
/**
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index ee6ce92ab4c3..1edfec1e9d18 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1424,6 +1424,7 @@ static int coresight_remove_match(struct device *dev, void *data)
* platform data.
*/
fwnode_handle_put(conn->child_fwnode);
+ conn->child_fwnode = NULL;
/* No need to continue */
break;
}
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index c039b6ae206f..43bbd5dc3d3b 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -52,6 +52,7 @@ static DEFINE_PER_CPU(struct coresight_device *, csdev_src);
* The PMU formats were orignally for ETMv3.5/PTM's ETMCR 'config';
* now take them as general formats and apply on all ETMs.
*/
+PMU_FORMAT_ATTR(branch_broadcast, "config:"__stringify(ETM_OPT_BRANCH_BROADCAST));
PMU_FORMAT_ATTR(cycacc, "config:" __stringify(ETM_OPT_CYCACC));
/* contextid1 enables tracing CONTEXTIDR_EL1 for ETMv4 */
PMU_FORMAT_ATTR(contextid1, "config:" __stringify(ETM_OPT_CTXTID));
@@ -97,6 +98,7 @@ static struct attribute *etm_config_formats_attr[] = {
&format_attr_sinkid.attr,
&format_attr_preset.attr,
&format_attr_configid.attr,
+ &format_attr_branch_broadcast.attr,
NULL,
};
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 87299e99dabb..cf249ecad5a5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -696,6 +696,20 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
}
+ /* branch broadcast - enable if selected and supported */
+ if (attr->config & BIT(ETM_OPT_BRANCH_BROADCAST)) {
+ if (!drvdata->trcbb) {
+ /*
+ * Missing BB support could cause silent decode errors
+ * so fail to open if it's not supported.
+ */
+ ret = -EINVAL;
+ goto out;
+ } else {
+ config->cfg |= BIT(ETM4_CFG_BIT_BB);
+ }
+ }
+
out:
return ret;
}
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 33869c1d20c3..a7bfea31f7d8 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -7,6 +7,7 @@
#define _CORESIGHT_CORESIGHT_ETM_H
#include <asm/local.h>
+#include <linux/const.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include "coresight-priv.h"
@@ -515,7 +516,7 @@
({ \
u64 __val; \
\
- if (__builtin_constant_p((offset))) \
+ if (__is_constexpr((offset))) \
__val = read_etm4x_sysreg_const_offset((offset)); \
else \
__val = etm4x_sysreg_read((offset), true, (_64bit)); \
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c
index 11850fd8c3b5..11138a9762b0 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg.c
+++ b/drivers/hwtracing/coresight/coresight-syscfg.c
@@ -415,6 +415,27 @@ static void cscfg_remove_owned_csdev_features(struct coresight_device *csdev, vo
}
/*
+ * Unregister all configuration and features from configfs owned by load_owner.
+ * Although this is called without the list mutex being held, it is in the
+ * context of an unload operation which are strictly serialised,
+ * so the lists cannot change during this call.
+ */
+static void cscfg_fs_unregister_cfgs_feats(void *load_owner)
+{
+ struct cscfg_config_desc *config_desc;
+ struct cscfg_feature_desc *feat_desc;
+
+ list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
+ if (config_desc->load_owner == load_owner)
+ cscfg_configfs_del_config(config_desc);
+ }
+ list_for_each_entry(feat_desc, &cscfg_mgr->feat_desc_list, item) {
+ if (feat_desc->load_owner == load_owner)
+ cscfg_configfs_del_feature(feat_desc);
+ }
+}
+
+/*
* removal is relatively easy - just remove from all lists, anything that
* matches the owner. Memory for the descriptors will be managed by the owner,
* memory for the csdev items is devm_ allocated with the individual csdev
@@ -426,6 +447,8 @@ static void cscfg_unload_owned_cfgs_feats(void *load_owner)
struct cscfg_feature_desc *feat_desc, *feat_tmp;
struct cscfg_registered_csdev *csdev_item;
+ lockdep_assert_held(&cscfg_mutex);
+
/* remove from each csdev instance feature and config lists */
list_for_each_entry(csdev_item, &cscfg_mgr->csdev_desc_list, item) {
/*
@@ -439,7 +462,6 @@ static void cscfg_unload_owned_cfgs_feats(void *load_owner)
/* remove from the config descriptor lists */
list_for_each_entry_safe(config_desc, cfg_tmp, &cscfg_mgr->config_desc_list, item) {
if (config_desc->load_owner == load_owner) {
- cscfg_configfs_del_config(config_desc);
etm_perf_del_symlink_cscfg(config_desc);
list_del(&config_desc->item);
}
@@ -448,12 +470,90 @@ static void cscfg_unload_owned_cfgs_feats(void *load_owner)
/* remove from the feature descriptor lists */
list_for_each_entry_safe(feat_desc, feat_tmp, &cscfg_mgr->feat_desc_list, item) {
if (feat_desc->load_owner == load_owner) {
- cscfg_configfs_del_feature(feat_desc);
list_del(&feat_desc->item);
}
}
}
+/*
+ * load the features and configs to the lists - called with list mutex held
+ */
+static int cscfg_load_owned_cfgs_feats(struct cscfg_config_desc **config_descs,
+ struct cscfg_feature_desc **feat_descs,
+ struct cscfg_load_owner_info *owner_info)
+{
+ int i, err;
+
+ lockdep_assert_held(&cscfg_mutex);
+
+ /* load features first */
+ if (feat_descs) {
+ for (i = 0; feat_descs[i]; i++) {
+ err = cscfg_load_feat(feat_descs[i]);
+ if (err) {
+ pr_err("coresight-syscfg: Failed to load feature %s\n",
+ feat_descs[i]->name);
+ return err;
+ }
+ feat_descs[i]->load_owner = owner_info;
+ }
+ }
+
+ /* next any configurations to check feature dependencies */
+ if (config_descs) {
+ for (i = 0; config_descs[i]; i++) {
+ err = cscfg_load_config(config_descs[i]);
+ if (err) {
+ pr_err("coresight-syscfg: Failed to load configuration %s\n",
+ config_descs[i]->name);
+ return err;
+ }
+ config_descs[i]->load_owner = owner_info;
+ config_descs[i]->available = false;
+ }
+ }
+ return 0;
+}
+
+/* set configurations as available to activate at the end of the load process */
+static void cscfg_set_configs_available(struct cscfg_config_desc **config_descs)
+{
+ int i;
+
+ lockdep_assert_held(&cscfg_mutex);
+
+ if (config_descs) {
+ for (i = 0; config_descs[i]; i++)
+ config_descs[i]->available = true;
+ }
+}
+
+/*
+ * Create and register each of the configurations and features with configfs.
+ * Called without mutex being held.
+ */
+static int cscfg_fs_register_cfgs_feats(struct cscfg_config_desc **config_descs,
+ struct cscfg_feature_desc **feat_descs)
+{
+ int i, err;
+
+ if (feat_descs) {
+ for (i = 0; feat_descs[i]; i++) {
+ err = cscfg_configfs_add_feature(feat_descs[i]);
+ if (err)
+ return err;
+ }
+ }
+ if (config_descs) {
+ for (i = 0; config_descs[i]; i++) {
+ err = cscfg_configfs_add_config(config_descs[i]);
+ if (err)
+ return err;
+ }
+ }
+ return 0;
+}
+
/**
* cscfg_load_config_sets - API function to load feature and config sets.
*
@@ -476,57 +576,63 @@ int cscfg_load_config_sets(struct cscfg_config_desc **config_descs,
struct cscfg_feature_desc **feat_descs,
struct cscfg_load_owner_info *owner_info)
{
- int err = 0, i = 0;
+ int err = 0;
mutex_lock(&cscfg_mutex);
-
- /* load features first */
- if (feat_descs) {
- while (feat_descs[i]) {
- err = cscfg_load_feat(feat_descs[i]);
- if (!err)
- err = cscfg_configfs_add_feature(feat_descs[i]);
- if (err) {
- pr_err("coresight-syscfg: Failed to load feature %s\n",
- feat_descs[i]->name);
- cscfg_unload_owned_cfgs_feats(owner_info);
- goto exit_unlock;
- }
- feat_descs[i]->load_owner = owner_info;
- i++;
- }
+ if (cscfg_mgr->load_state != CSCFG_NONE) {
+ mutex_unlock(&cscfg_mutex);
+ return -EBUSY;
}
+ cscfg_mgr->load_state = CSCFG_LOAD;
- /* next any configurations to check feature dependencies */
- i = 0;
- if (config_descs) {
- while (config_descs[i]) {
- err = cscfg_load_config(config_descs[i]);
- if (!err)
- err = cscfg_configfs_add_config(config_descs[i]);
- if (err) {
- pr_err("coresight-syscfg: Failed to load configuration %s\n",
- config_descs[i]->name);
- cscfg_unload_owned_cfgs_feats(owner_info);
- goto exit_unlock;
- }
- config_descs[i]->load_owner = owner_info;
- i++;
- }
- }
+ /* first load and add to the lists */
+ err = cscfg_load_owned_cfgs_feats(config_descs, feat_descs, owner_info);
+ if (err)
+ goto err_clean_load;
/* add the load owner to the load order list */
list_add_tail(&owner_info->item, &cscfg_mgr->load_order_list);
if (!list_is_singular(&cscfg_mgr->load_order_list)) {
/* lock previous item in load order list */
err = cscfg_owner_get(list_prev_entry(owner_info, item));
- if (err) {
- cscfg_unload_owned_cfgs_feats(owner_info);
- list_del(&owner_info->item);
- }
+ if (err)
+ goto err_clean_owner_list;
}
+ /*
+ * make visible to configfs - configfs manipulation must occur outside
+ * the list mutex lock to avoid circular lockdep issues with configfs
+ * built in mutexes and semaphores. This is safe as it is not possible
+ * to start a new load/unload operation till the current one is done.
+ */
+ mutex_unlock(&cscfg_mutex);
+
+ /* create the configfs elements */
+ err = cscfg_fs_register_cfgs_feats(config_descs, feat_descs);
+ mutex_lock(&cscfg_mutex);
+
+ if (err)
+ goto err_clean_cfs;
+
+ /* mark any new configs as available for activation */
+ cscfg_set_configs_available(config_descs);
+ goto exit_unlock;
+
+err_clean_cfs:
+ /* cleanup after error registering with configfs */
+ cscfg_fs_unregister_cfgs_feats(owner_info);
+
+ if (!list_is_singular(&cscfg_mgr->load_order_list))
+ cscfg_owner_put(list_prev_entry(owner_info, item));
+
+err_clean_owner_list:
+ list_del(&owner_info->item);
+
+err_clean_load:
+ cscfg_unload_owned_cfgs_feats(owner_info);
+
exit_unlock:
+ cscfg_mgr->load_state = CSCFG_NONE;
mutex_unlock(&cscfg_mutex);
return err;
}
@@ -543,6 +649,9 @@ EXPORT_SYMBOL_GPL(cscfg_load_config_sets);
* 1) no configurations are active.
* 2) the set being unloaded was the last to be loaded to maintain dependencies.
*
+ * Once the unload operation commences, we disallow any configuration being
+ * made active until it is complete.
+ *
* @owner_info: Information on owner for set being unloaded.
*/
int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
@@ -551,6 +660,13 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
struct cscfg_load_owner_info *load_list_item = NULL;
mutex_lock(&cscfg_mutex);
+ if (cscfg_mgr->load_state != CSCFG_NONE) {
+ mutex_unlock(&cscfg_mutex);
+ return -EBUSY;
+ }
+
+ /* unload op in progress also prevents activation of any config */
+ cscfg_mgr->load_state = CSCFG_UNLOAD;
/* cannot unload if anything is active */
if (atomic_read(&cscfg_mgr->sys_active_cnt)) {
@@ -571,7 +687,12 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
goto exit_unlock;
}
- /* unload all belonging to load_owner */
+ /* remove from configfs - again outside the scope of the list mutex */
+ mutex_unlock(&cscfg_mutex);
+ cscfg_fs_unregister_cfgs_feats(owner_info);
+ mutex_lock(&cscfg_mutex);
+
+ /* unload everything from lists belonging to load_owner */
cscfg_unload_owned_cfgs_feats(owner_info);
/* remove from load order list */
@@ -582,6 +703,7 @@ int cscfg_unload_config_sets(struct cscfg_load_owner_info *owner_info)
list_del(&owner_info->item);
exit_unlock:
+ cscfg_mgr->load_state = CSCFG_NONE;
mutex_unlock(&cscfg_mutex);
return err;
}
@@ -759,8 +881,15 @@ static int _cscfg_activate_config(unsigned long cfg_hash)
struct cscfg_config_desc *config_desc;
int err = -EINVAL;
+ if (cscfg_mgr->load_state == CSCFG_UNLOAD)
+ return -EBUSY;
+
list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {
+ /* if we happen upon a partly loaded config, can't use it */
+ if (config_desc->available == false)
+ return -EBUSY;
+
/* must ensure that config cannot be unloaded in use */
err = cscfg_owner_get(config_desc->load_owner);
if (err)
@@ -1022,8 +1151,10 @@ struct device *cscfg_device(void)
/* Must have a release function or the kernel will complain on module unload */
static void cscfg_dev_release(struct device *dev)
{
+ mutex_lock(&cscfg_mutex);
kfree(cscfg_mgr);
cscfg_mgr = NULL;
+ mutex_unlock(&cscfg_mutex);
}
/* a device is needed to "own" some kernel elements such as sysfs entries. */
@@ -1042,6 +1173,14 @@ static int cscfg_create_device(void)
if (!cscfg_mgr)
goto create_dev_exit_unlock;
+ /* initialise the cscfg_mgr structure */
+ INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list);
+ INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list);
+ INIT_LIST_HEAD(&cscfg_mgr->config_desc_list);
+ INIT_LIST_HEAD(&cscfg_mgr->load_order_list);
+ atomic_set(&cscfg_mgr->sys_active_cnt, 0);
+ cscfg_mgr->load_state = CSCFG_NONE;
+
/* setup the device */
dev = cscfg_device();
dev->release = cscfg_dev_release;
@@ -1056,17 +1195,73 @@ create_dev_exit_unlock:
return err;
}
-static void cscfg_clear_device(void)
+/*
+ * Loading and unloading is generally on user discretion.
+ * If exiting due to coresight module unload, we need to unload any configurations that remain,
+ * before we unregister the configfs intrastructure.
+ *
+ * Do this by walking the load_owner list and taking appropriate action, depending on the load
+ * owner type.
+ */
+static void cscfg_unload_cfgs_on_exit(void)
{
- struct cscfg_config_desc *cfg_desc;
+ struct cscfg_load_owner_info *owner_info = NULL;
+ /*
+ * grab the mutex - even though we are exiting, some configfs files
+ * may still be live till we dump them, so ensure list data is
+ * protected from a race condition.
+ */
mutex_lock(&cscfg_mutex);
- list_for_each_entry(cfg_desc, &cscfg_mgr->config_desc_list, item) {
- etm_perf_del_symlink_cscfg(cfg_desc);
+ while (!list_empty(&cscfg_mgr->load_order_list)) {
+
+ /* remove in reverse order of loading */
+ owner_info = list_last_entry(&cscfg_mgr->load_order_list,
+ struct cscfg_load_owner_info, item);
+
+ /* action according to type */
+ switch (owner_info->type) {
+ case CSCFG_OWNER_PRELOAD:
+ /*
+ * preloaded descriptors are statically allocated in
+ * this module - just need to unload dynamic items from
+ * csdev lists, and remove from configfs directories.
+ */
+ pr_info("cscfg: unloading preloaded configurations\n");
+ break;
+
+ case CSCFG_OWNER_MODULE:
+ /*
+ * this is an error - the loadable module must have been unloaded prior
+ * to the coresight module unload. Therefore that module has not
+ * correctly unloaded configs in its own exit code.
+ * Nothing to do other than emit an error string as the static descriptor
+ * references we need to unload will have disappeared with the module.
+ */
+ pr_err("cscfg: ERROR: prior module failed to unload configuration\n");
+ goto list_remove;
+ }
+
+ /* remove from configfs - outside the scope of the list mutex */
+ mutex_unlock(&cscfg_mutex);
+ cscfg_fs_unregister_cfgs_feats(owner_info);
+ mutex_lock(&cscfg_mutex);
+
+ /* Next unload from csdev lists. */
+ cscfg_unload_owned_cfgs_feats(owner_info);
+
+list_remove:
+ /* remove from load order list */
+ list_del(&owner_info->item);
}
+ mutex_unlock(&cscfg_mutex);
+}
+
+static void cscfg_clear_device(void)
+{
+ cscfg_unload_cfgs_on_exit();
cscfg_configfs_release(cscfg_mgr);
device_unregister(cscfg_device());
- mutex_unlock(&cscfg_mutex);
}
/* Initialise system config management API device */
@@ -1074,20 +1269,16 @@ int __init cscfg_init(void)
{
int err = 0;
+ /* create the device and init cscfg_mgr */
err = cscfg_create_device();
if (err)
return err;
+ /* initialise configfs subsystem */
err = cscfg_configfs_init(cscfg_mgr);
if (err)
goto exit_err;
- INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list);
- INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list);
- INIT_LIST_HEAD(&cscfg_mgr->config_desc_list);
- INIT_LIST_HEAD(&cscfg_mgr->load_order_list);
- atomic_set(&cscfg_mgr->sys_active_cnt, 0);
-
/* preload built-in configurations */
err = cscfg_preload(THIS_MODULE);
if (err)
diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h
index 9106ffab4833..66e2db890d82 100644
--- a/drivers/hwtracing/coresight/coresight-syscfg.h
+++ b/drivers/hwtracing/coresight/coresight-syscfg.h
@@ -12,6 +12,17 @@
#include "coresight-config.h"
+/*
+ * Load operation types.
+ * When loading or unloading, another load operation cannot be run.
+ * When unloading configurations cannot be activated.
+ */
+enum cscfg_load_ops {
+ CSCFG_NONE,
+ CSCFG_LOAD,
+ CSCFG_UNLOAD
+};
+
/**
* System configuration manager device.
*
@@ -30,6 +41,7 @@
* @cfgfs_subsys: configfs subsystem used to manage configurations.
* @sysfs_active_config:Active config hash used if CoreSight controlled from sysfs.
* @sysfs_active_preset:Active preset index used if CoreSight controlled from sysfs.
+ * @load_state: A multi-stage load/unload operation is in progress.
*/
struct cscfg_manager {
struct device dev;
@@ -41,6 +53,7 @@ struct cscfg_manager {
struct configfs_subsystem cfgfs_subsys;
u32 sysfs_active_config;
int sysfs_active_preset;
+ enum cscfg_load_ops load_state;
};
/* get reference to dev in cscfg_manager */