Delay probe the cpu cluster funnel when all CPUs of this cluster are offline, re-probe the funnel when any CPU in the cluster comes online.
Key changes: - Introduce a global list to track delayed funnels waiting for CPU online. - Add CPU hotplug callback to retry registration when the CPU comes up.
Signed-off-by: Yuanfang Zhang yuanfang.zhang@oss.qualcomm.com --- drivers/hwtracing/coresight/coresight-funnel.c | 62 +++++++++++++++++++++++--- 1 file changed, 57 insertions(+), 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c index 12c29eb98b2122a3ade4cbed9a0d91c67ec777ed..43b9287a865eb26ce021521e4a5f193c48188bba 100644 --- a/drivers/hwtracing/coresight/coresight-funnel.c +++ b/drivers/hwtracing/coresight/coresight-funnel.c @@ -32,6 +32,9 @@ #define FUNNEL_ENSx_MASK 0xff
DEFINE_CORESIGHT_DEVLIST(funnel_devs, "funnel"); +static LIST_HEAD(funnel_delay_probe); +static enum cpuhp_state hp_online; +static DEFINE_SPINLOCK(delay_lock);
/** * struct funnel_drvdata - specifics associated to a funnel component @@ -42,6 +45,8 @@ DEFINE_CORESIGHT_DEVLIST(funnel_devs, "funnel"); * @priority: port selection order. * @spinlock: serialize enable/disable operations. * @cpumask: CPU mask representing the CPUs related to this funnel. + * @dev: pointer to the device associated with this funnel. + * @link: list node for adding this funnel to the delayed probe list. */ struct funnel_drvdata { void __iomem *base; @@ -51,6 +56,8 @@ struct funnel_drvdata { unsigned long priority; raw_spinlock_t spinlock; struct cpumask *cpumask; + struct device *dev; + struct list_head link; };
struct funnel_smp_arg { @@ -372,7 +379,7 @@ static int funnel_probe(struct device *dev, struct resource *res) drvdata->cpumask = funnel_get_cpumask(dev); if (!drvdata->cpumask) return -EINVAL; - + drvdata->dev = dev; cpus_read_lock(); for_each_cpu(cpu, drvdata->cpumask) { ret = smp_call_function_single(cpu, @@ -380,10 +387,15 @@ static int funnel_probe(struct device *dev, struct resource *res) if (!ret) break; } - cpus_read_unlock();
- if (ret) + if (ret) { + scoped_guard(spinlock, &delay_lock) + list_add(&drvdata->link, &funnel_delay_probe); + cpus_read_unlock(); return 0; + } + + cpus_read_unlock(); } else if (res) { funnel_clear_self_claim_tag(drvdata); } @@ -395,9 +407,12 @@ static int funnel_remove(struct device *dev) { struct funnel_drvdata *drvdata = dev_get_drvdata(dev);
- if (drvdata->csdev) + if (drvdata->csdev) { coresight_unregister(drvdata->csdev); - + } else { + scoped_guard(spinlock, &delay_lock) + list_del(&drvdata->link); + } return 0; }
@@ -535,8 +550,41 @@ static struct amba_driver dynamic_funnel_driver = { .id_table = dynamic_funnel_ids, };
+static int funnel_online_cpu(unsigned int cpu) +{ + struct funnel_drvdata *drvdata, *tmp; + int ret; + + list_for_each_entry_safe(drvdata, tmp, &funnel_delay_probe, link) { + if (cpumask_test_cpu(cpu, drvdata->cpumask)) { + scoped_guard(spinlock, &delay_lock) + list_del(&drvdata->link); + + ret = pm_runtime_resume_and_get(drvdata->dev); + if (ret < 0) + return 0; + + funnel_clear_self_claim_tag(drvdata); + funnel_add_coresight_dev(drvdata->dev); + pm_runtime_put(drvdata->dev); + } + } + return 0; +} + static int __init funnel_init(void) { + int ret; + + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "arm/coresight-funnel:online", + funnel_online_cpu, NULL); + + if (ret > 0) + hp_online = ret; + else + return ret; + return coresight_init_driver("funnel", &dynamic_funnel_driver, &funnel_driver, THIS_MODULE); } @@ -544,6 +592,10 @@ static int __init funnel_init(void) static void __exit funnel_exit(void) { coresight_remove_driver(&dynamic_funnel_driver, &funnel_driver); + if (hp_online) { + cpuhp_remove_state_nocalls(hp_online); + hp_online = 0; + } }
module_init(funnel_init);