@@ -1225,6 +1225,16 @@ static void arm_trbe_enable_cpu(void *info)
enable_percpu_irq(drvdata->irq, IRQ_TYPE_NONE);
}
+static void arm_trbe_disable_cpu(void *info)
+{
+ struct trbe_drvdata *drvdata = info;
+ struct trbe_cpudata *cpudata = this_cpu_ptr(drvdata->cpudata);
+
+ disable_percpu_irq(drvdata->irq);
+ trbe_reset_local(cpudata);
+}
+
+
static void arm_trbe_register_coresight_cpu(struct trbe_drvdata *drvdata, int cpu)
{
struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
@@ -1329,18 +1339,12 @@ static void arm_trbe_probe_cpu(void *info)
cpumask_clear_cpu(cpu, &drvdata->supported_cpus);
}
-static void arm_trbe_remove_coresight_cpu(void *info)
+static void arm_trbe_remove_coresight_cpu(struct trbe_drvdata *drvdata, int cpu)
{
- int cpu = smp_processor_id();
- struct trbe_drvdata *drvdata = info;
- struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
struct coresight_device *trbe_csdev = coresight_get_percpu_sink(cpu);
- disable_percpu_irq(drvdata->irq);
- trbe_reset_local(cpudata);
if (trbe_csdev) {
coresight_unregister(trbe_csdev);
- cpudata->drvdata = NULL;
coresight_set_percpu_sink(cpu, NULL);
}
}
@@ -1369,8 +1373,10 @@ static int arm_trbe_remove_coresight(struct trbe_drvdata *drvdata)
{
int cpu;
- for_each_cpu(cpu, &drvdata->supported_cpus)
- smp_call_function_single(cpu, arm_trbe_remove_coresight_cpu, drvdata, 1);
+ for_each_cpu(cpu, &drvdata->supported_cpus) {
+ smp_call_function_single(cpu, arm_trbe_disable_cpu, drvdata, 1);
+ arm_trbe_remove_coresight_cpu(drvdata, cpu);
+ }
free_percpu(drvdata->cpudata);
return 0;
}
@@ -1409,12 +1415,8 @@ static int arm_trbe_cpu_teardown(unsigned int cpu, struct hlist_node *node)
{
struct trbe_drvdata *drvdata = hlist_entry_safe(node, struct trbe_drvdata, hotplug_node);
- if (cpumask_test_cpu(cpu, &drvdata->supported_cpus)) {
- struct trbe_cpudata *cpudata = per_cpu_ptr(drvdata->cpudata, cpu);
-
- disable_percpu_irq(drvdata->irq);
- trbe_reset_local(cpudata);
- }
+ if (cpumask_test_cpu(cpu, &drvdata->supported_cpus))
+ arm_trbe_disable_cpu(drvdata);
return 0;
}
smp_call_function_single() will allocate an IPI interrupt vector to the target processor and send a function call request to the interrupt vector. After the target processor receives the IPI interrupt, it will execute arm_trbe_remove_coresight_cpu() call request in the interrupt handler. According to the device_unregister() stack information, if other process is useing the device, the down_write() may sleep, and trigger deadlocks or unexpected errors. arm_trbe_remove_coresight_cpu coresight_unregister device_unregister device_del kobject_del __kobject_del sysfs_remove_dir kernfs_remove down_write ---------> it may sleep Add a helper arm_trbe_disable_cpu() to disable TRBE precpu irq and reset per TRBE. Simply call arm_trbe_remove_coresight_cpu() directly without useing the smp_call_function_single(), which is the same as registering the TRBE coresight device. Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver") Signed-off-by: Junhao He <hejunhao3@huawei.com> Link: https://lore.kernel.org/r/20230814093813.19152-2-hejunhao3@huawei.com [ Remove duplicate cpumask checks during removal ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> [ v3 - Remove the operation of assigning NULL to cpudata->drvdata ] --- drivers/hwtracing/coresight/coresight-trbe.c | 32 +++++++++++--------- 1 file changed, 17 insertions(+), 15 deletions(-)