On 4/14/21 8:18 PM, Mike Leach wrote:
Configurations are first activated, then when any coresight device is enabled, the active configurations are checked and any matching one is enabled.
This patch provides the activation / enable API.
Signed-off-by: Mike Leach mike.leach@linaro.org Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org
.../hwtracing/coresight/coresight-config.h | 2 + .../hwtracing/coresight/coresight-syscfg.c | 172 ++++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 8 + include/linux/coresight.h | 2 + 4 files changed, 184 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-config.h b/drivers/hwtracing/coresight/coresight-config.h index 0667581822c1..25eb6c632692 100644 --- a/drivers/hwtracing/coresight/coresight-config.h +++ b/drivers/hwtracing/coresight/coresight-config.h @@ -127,6 +127,7 @@ struct cscfg_feature_desc {
- @nr_total_params: Sum of all parameters declared by used features
- @presets: Array of preset values.
- @event_ea: Extended attribute for perf event value
*/ struct cscfg_config_desc {
- @active_cnt: ref count for activate on this configuration.
@@ -139,6 +140,7 @@ struct cscfg_config_desc { int nr_total_params; const u64 *presets; /* nr_presets * nr_total_params */ struct dev_ext_attribute *event_ea;
- atomic_t active_cnt; };
/** diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtracing/coresight/coresight-syscfg.c index e35f8c0ac2f8..b234e45c153f 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -283,6 +283,7 @@ static int cscfg_load_config(struct cscfg_config_desc *config_desc) return err; list_add(&config_desc->item, &cscfg_mgr->config_desc_list);
- atomic_set(&config_desc->active_cnt, 0); return 0; }
@@ -468,6 +469,176 @@ void cscfg_unregister_csdev(struct coresight_device *csdev) } EXPORT_SYMBOL_GPL(cscfg_unregister_csdev); +/**
- cscfg_csdev_reset_feats - reset features for a CoreSight device.
- Resets all parameters and register values for any features loaded
- into @csdev to their default values.
- @csdev: The CoreSight device.
- */
+void cscfg_csdev_reset_feats(struct coresight_device *csdev) +{
- struct cscfg_feature_csdev *feat_csdev;
- mutex_lock(&cscfg_csdev_mutex);
- if (list_empty(&csdev->feature_csdev_list))
goto unlock_exit;- list_for_each_entry(feat_csdev, &csdev->feature_csdev_list, node)
cscfg_reset_feat(feat_csdev);+unlock_exit:
- mutex_unlock(&cscfg_csdev_mutex);
+} +EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats);
+/**
- cscfg_activate_config - Mark a configuration descriptor as active.
- This will be seen when csdev devices are enabled in the system.
- Only activated configurations can be enabled on individual devices.
- Activation protects the configuration from alteration or removal while
- active.
- Selection by hash value - generated from the configuration name when it
- was loaded and added to the cs_etm/configurations file system for selection
- by perf.
- Increments the configuration descriptor active count and the global active
- count.
- @cfg_hash: Hash value of the selected configuration name.
- */
+int cscfg_activate_config(unsigned long cfg_hash) +{
- struct cscfg_config_desc *config_desc;
- int err = -EINVAL;
- mutex_lock(&cscfg_mutex);
- list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {/** increment the global active count - control changes to* active configurations*/atomic_inc(&cscfg_mgr->sys_active_cnt);/** mark the descriptor as active so enable config on a* device instance will use it*/atomic_inc(&config_desc->active_cnt);err = 0;dev_dbg(cscfg_device(), "Activate config %s.\n", config_desc->name);break;}- }
- mutex_unlock(&cscfg_mutex);
- return err;
+} +EXPORT_SYMBOL_GPL(cscfg_activate_config);
+/**
- cscfg_deactivate_config - Mark a config descriptor as inactive.
- Decrement the configuration and global active counts.
- @cfg_hash: Hash value of the selected configuration name.
- */
+void cscfg_deactivate_config(unsigned long cfg_hash) +{
- struct cscfg_config_desc *config_desc;
- mutex_lock(&cscfg_mutex);
- list_for_each_entry(config_desc, &cscfg_mgr->config_desc_list, item) {
if ((unsigned long)config_desc->event_ea->var == cfg_hash) {atomic_dec(&config_desc->active_cnt);atomic_dec(&cscfg_mgr->sys_active_cnt);dev_dbg(cscfg_device(), "Deactivate config %s.\n", config_desc->name);break;}- }
- mutex_unlock(&cscfg_mutex);
+} +EXPORT_SYMBOL_GPL(cscfg_deactivate_config);
+/**
- cscfg_csdev_enable_active_config - Enable matching active configuration for device.
- Enables the configuration selected by @cfg_hash if the configuration is supported
- on the device and has been activated.
- If active and supported the CoreSight device @csdev will be programmed with the
- configuration, using @preset parameters.
- Should be called before driver hardware enable for the requested device, prior to
- programming and enabling the physical hardware.
- @csdev: CoreSight device to program.
- @cfg_hash: Selector for the configuration.
- @preset: Preset parameter values to use, 0 for current / default values.
- */
+int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
unsigned long cfg_hash, int preset)+{
- struct cscfg_config_csdev *config_csdev_active = NULL, *config_csdev_item;
- const struct cscfg_config_desc *config_desc;
- int err = 0;
- /* quickly check global count */
- if (!atomic_read(&cscfg_mgr->sys_active_cnt))
return 0;- mutex_lock(&cscfg_csdev_mutex);
- list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) {
config_desc = config_csdev_item->config_desc;if ((atomic_read(&config_desc->active_cnt)) &&((unsigned long)config_desc->event_ea->var == cfg_hash)) {config_csdev_active = config_csdev_item;break;}- }
- if (config_csdev_active) {
err = cscfg_csdev_enable_config(config_csdev_active, preset);if (!err)csdev->active_cscfg_ctxt = (void *)config_csdev_active;- }
- mutex_unlock(&cscfg_csdev_mutex);
- return err;
+} +EXPORT_SYMBOL_GPL(cscfg_csdev_enable_active_config);
+/**
- cscfg_csdev_disable_active_config - disable an active config on the device.
- Disables the active configuration on the CoreSight device @csdev.
- Disable will save the values of any registers marked in the configurations
- as save on disable.
- Should be called after driver hardware disable for the requested device,
- after disabling the physical hardware and reading back registers.
- @csdev: The CoreSight device.
- */
+void cscfg_csdev_disable_active_config(struct coresight_device *csdev) +{
- struct cscfg_config_csdev *config_csdev;
- mutex_lock(&cscfg_csdev_mutex);
This line seems to cause a bug report when the kernel is compiled with CONFIG_DEBUG_ATOMIC_SLEEP=y
I have tested this by applying the series to 5.10 kernel on Dragonboard 845c.
It only happens when strobing is used.
The report is this:
[13431.885395] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283 [13431.893919] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 3525, name: perf [13431.901882] CPU: 0 PID: 3525 Comm: perf Tainted: G W 5.10.0-rc5-17282-g923b456a55fb #124 [13431.911436] Hardware name: Thundercomm Dragonboard 845c (DT) [13431.917450] Call trace: [13431.919938] dump_backtrace+0x0/0x1a0 [13431.923644] show_stack+0x18/0x68 [13431.927008] dump_stack+0xd0/0x12c [13431.930444] ___might_sleep+0xf0/0x130 [13431.934228] __might_sleep+0x54/0x90 [13431.937945] mutex_lock+0x28/0x80 [13431.941468] cscfg_csdev_disable_active_config+0x24/0x50 [13431.946952] etm4_disable+0xf0/0x100 [13431.950571] etm_event_stop+0xb8/0x130 [13431.954380] etm_event_del+0x14/0x20 [13431.958008] event_sched_out.isra.0+0x84/0x1c8 [13431.962496] group_sched_out.part.0+0x44/0xc8 [13431.967010] __perf_event_disable+0xe4/0x198 [13431.971549] event_function+0x8c/0xe8 [13431.975256] remote_function+0x64/0x78 [13431.979161] generic_exec_single+0xa0/0x100 [13431.983876] smp_call_function_single+0x158/0x1d8 [13431.988629] event_function_call+0x128/0x138 [13431.992942] _perf_event_disable+0x48/0x70 [13431.997082] perf_event_for_each_child+0x3c/0x90 [13432.001751] _perf_ioctl+0x198/0x4a8 [13432.005359] perf_ioctl+0x4c/0x78 [13432.008715] __arm64_sys_ioctl+0xa8/0xf0 [13432.012835] el0_svc_common.constprop.0+0x78/0x1a0 [13432.017767] do_el0_svc+0x24/0x90 [13432.021616] el0_sync_handler+0x160/0x168 [13432.025670] el0_sync+0x174/0x180
- config_csdev = (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt;
- if (config_csdev) {
cscfg_csdev_disable_config(config_csdev);csdev->active_cscfg_ctxt = NULL;- }
- mutex_unlock(&cscfg_csdev_mutex);
+} +EXPORT_SYMBOL_GPL(cscfg_csdev_disable_active_config);
- /* Initialise system configuration management device. */
struct device *cscfg_device(void) @@ -536,6 +707,7 @@ int __init cscfg_init(void) INIT_LIST_HEAD(&cscfg_mgr->csdev_desc_list); INIT_LIST_HEAD(&cscfg_mgr->feat_desc_list); INIT_LIST_HEAD(&cscfg_mgr->config_desc_list);
- atomic_set(&cscfg_mgr->sys_active_cnt, 0);
dev_info(cscfg_device(), "CoreSight Configuration manager initialised"); return 0; diff --git a/drivers/hwtracing/coresight/coresight-syscfg.h b/drivers/hwtracing/coresight/coresight-syscfg.h index 5bcae3b374c6..a52775890670 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.h +++ b/drivers/hwtracing/coresight/coresight-syscfg.h @@ -24,12 +24,14 @@
- @csdev_desc_list: List of coresight devices registered with the configuration manager.
- @feat_desc_list: List of feature descriptors to load into registered devices.
- @config_desc_list: List of system configuration descriptors to load into registered devices.
*/ struct cscfg_manager { struct device dev; struct list_head csdev_desc_list; struct list_head feat_desc_list; struct list_head config_desc_list;
- @sys_active_cnt: Total number of active config descriptor references.
- atomic_t sys_active_cnt; };
/* get reference to dev in cscfg_manager */ @@ -61,5 +63,11 @@ int cscfg_load_config_sets(struct cscfg_config_desc **cfg_descs, int cscfg_register_csdev(struct coresight_device *csdev, u32 match_flags, struct cscfg_csdev_feat_ops *ops); void cscfg_unregister_csdev(struct coresight_device *csdev); +int cscfg_activate_config(unsigned long cfg_hash); +void cscfg_deactivate_config(unsigned long cfg_hash); +void cscfg_csdev_reset_feats(struct coresight_device *csdev); +int cscfg_csdev_enable_active_config(struct coresight_device *csdev,
unsigned long cfg_hash, int preset);+void cscfg_csdev_disable_active_config(struct coresight_device *csdev); #endif /* CORESIGHT_SYSCFG_H */ diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 6fb516e1b22e..a348049ee08b 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -222,6 +222,7 @@ struct coresight_sysfs_link {
- @has_conns_grp: Have added a "connections" group for sysfs links.
- @feature_csdev_list: List of complex feature programming added to the device.
- @config_csdev_list: List of system configurations added to the device.
*/ struct coresight_device { struct coresight_platform_data *pdata;
- @active_cscfg_ctxt: Context information for current active system configuration.
@@ -246,6 +247,7 @@ struct coresight_device { /* system configuration and feature lists */ struct list_head feature_csdev_list; struct list_head config_csdev_list;
- void *active_cscfg_ctxt; };
/*