Delay probe the CPU cluster replicator when all CPUs of the cluster are offline, and re-probe the replicator when any CPU in the cluster comes online.
Key changes: - Maintain a global list to track delayed replicators waiting for CPU online. - Add a CPU hotplug callback to retry registration on CPU online events.
Signed-off-by: Yuanfang Zhang yuanfang.zhang@oss.qualcomm.com --- drivers/hwtracing/coresight/coresight-replicator.c | 65 ++++++++++++++++++++-- 1 file changed, 61 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c index c5a9c7a2adfa90ae22890ed730fc008fe6901778..1dfe11940cd6001db3cf17249b0493027b65e19c 100644 --- a/drivers/hwtracing/coresight/coresight-replicator.c +++ b/drivers/hwtracing/coresight/coresight-replicator.c @@ -26,6 +26,9 @@ #define REPLICATOR_IDFILTER1 0x004
DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator"); +static LIST_HEAD(replicator_delay_probe); +static enum cpuhp_state hp_online; +static DEFINE_SPINLOCK(delay_lock);
/** * struct replicator_drvdata - specifics associated to a replicator component @@ -37,6 +40,8 @@ DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator"); * @spinlock: serialize enable/disable operations. * @check_idfilter_val: check if the context is lost upon clock removal. * @cpumask: CPU mask representing the CPUs related to this replicator. + * @dev: pointer to the device associated with this replicator. + * @link: link to the delay_probed list. */ struct replicator_drvdata { void __iomem *base; @@ -46,6 +51,8 @@ struct replicator_drvdata { raw_spinlock_t spinlock; bool check_idfilter_val; struct cpumask *cpumask; + struct device *dev; + struct list_head link; };
struct replicator_smp_arg { @@ -395,7 +402,7 @@ static int replicator_probe(struct device *dev, struct resource *res) drvdata->cpumask = replicator_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, @@ -403,10 +410,15 @@ static int replicator_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, &replicator_delay_probe); + cpus_read_unlock(); return 0; + } + + cpus_read_unlock(); } else if (res) { replicator_init_hw(drvdata); } @@ -420,8 +432,13 @@ static int replicator_remove(struct device *dev) { struct replicator_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; }
@@ -554,8 +571,44 @@ static struct amba_driver dynamic_replicator_driver = { .id_table = dynamic_replicator_ids, };
+static int replicator_online_cpu(unsigned int cpu) +{ + struct replicator_drvdata *drvdata, *tmp; + int ret; + + spin_lock(&delay_lock); + list_for_each_entry_safe(drvdata, tmp, &replicator_delay_probe, link) { + if (cpumask_test_cpu(cpu, drvdata->cpumask)) { + list_del(&drvdata->link); + spin_unlock(&delay_lock); + ret = pm_runtime_resume_and_get(drvdata->dev); + if (ret < 0) + return 0; + + replicator_clear_self_claim_tag(drvdata); + replicator_reset(drvdata); + replicator_add_coresight_dev(drvdata->dev); + pm_runtime_put(drvdata->dev); + spin_lock(&delay_lock); + } + } + spin_unlock(&delay_lock); + return 0; +} + static int __init replicator_init(void) { + int ret; + + ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, + "arm/coresight-replicator:online", + replicator_online_cpu, NULL); + + if (ret > 0) + hp_online = ret; + else + return ret; + return coresight_init_driver("replicator", &dynamic_replicator_driver, &replicator_driver, THIS_MODULE); } @@ -563,6 +616,10 @@ static int __init replicator_init(void) static void __exit replicator_exit(void) { coresight_remove_driver(&dynamic_replicator_driver, &replicator_driver); + if (hp_online) { + cpuhp_remove_state_nocalls(hp_online); + hp_online = 0; + } }
module_init(replicator_init);