ACPI firmware can trigger the events to add and remove CPUs, but the
OS may not support this.
Print a warning when this happens.
This gives early warning on arm64 systems that don't support
CONFIG_ACPI_HOTPLUG_PRESENT_CPU, as making CPUs not present has
side effects for other parts of the system.
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
drivers/acpi/acpi_processor.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 2cafea1edc24..b67616079751 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -188,8 +188,10 @@ static int acpi_processor_make_present(struct acpi_processor *pr)
acpi_status status;
int ret;
- if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU))
+ if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) {
+ pr_err_once("Changing CPU present bit is not supported\n");
return -ENODEV;
+ }
if (invalid_phys_cpuid(pr->phys_id))
return -ENODEV;
@@ -462,8 +464,10 @@ static void acpi_processor_make_not_present(struct acpi_device *device)
{
struct acpi_processor *pr;
- if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU))
+ if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) {
+ pr_err_once("Changing CPU present bit is not supported");
return;
+ }
pr = acpi_driver_data(device);
if (pr->id >= nr_cpu_ids)
--
2.39.2
