diff options
| author | James Morse <james.morse@arm.com> | 2022-11-02 16:15:24 +0000 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2023-08-29 15:30:18 +0100 |
| commit | b74a4ba60fbf9e3f5fbcca347176c214dee19a68 (patch) | |
| tree | 4e092e70cc20d43fe510aa6797a5bc60ade210dc /drivers/base | |
| parent | 4713d1ec441c56edde6e9f9582848893087c8209 (diff) | |
cpumask: Add enabled cpumask for present CPUs that can be brought onlinevcpu-rmkaarch64/hotplug-vcpu/v6.5
The 'offline' file in sysfs shows all offline CPUs, including those
that aren't present. User-space is expected to remove not-present CPUs
from thie list to learn which CPUs could be brought online.
CPUs can be present but not-enabled. These CPUs can't be brought online
until the firmware policy changes, which comes with an ACPI notification
that will register the CPUs.
With only the offline and present files, user-space is unable to
determine which CPUs it can try to bring online. Add a new CPU mask
that shows this based on all the registered CPUs.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/cpu.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index f572d1f182fc..b96367da685b 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -76,6 +76,7 @@ void unregister_cpu(struct cpu *cpu) { int logical_cpu = cpu->dev.id; + set_cpu_enabled(logical_cpu, false); unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); device_unregister(&cpu->dev); @@ -254,6 +255,13 @@ static ssize_t print_cpus_offline(struct device *dev, } static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); +static ssize_t print_cpus_enabled(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_enabled_mask)); +} +static DEVICE_ATTR(enabled, 0444, print_cpus_enabled, NULL); + static ssize_t print_cpus_isolated(struct device *dev, struct device_attribute *attr, char *buf) { @@ -384,6 +392,7 @@ int register_cpu(struct cpu *cpu, int num) register_cpu_under_node(num, cpu_to_node(num)); dev_pm_qos_expose_latency_limit(&cpu->dev, PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); + set_cpu_enabled(num, true); return 0; } @@ -465,6 +474,7 @@ static struct attribute *cpu_root_attrs[] = { &cpu_attrs[2].attr.attr, &dev_attr_kernel_max.attr, &dev_attr_offline.attr, + &dev_attr_enabled.attr, &dev_attr_isolated.attr, #ifdef CONFIG_NO_HZ_FULL &dev_attr_nohz_full.attr, |