diff mbox series

[RFC,19/32] ACPI: Warn when the present bit changes but the feature is not enabled

Message ID 20230203135043.409192-20-james.morse@arm.com (mailing list archive)
State RFC, archived
Headers show
Series ACPI/arm64: add support for virtual cpuhotplug | expand

Commit Message

James Morse Feb. 3, 2023, 1:50 p.m. UTC 
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@arm.com>
---
 drivers/acpi/acpi_processor.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index e6419b06cb37..572a12672c0e 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -155,8 +155,10 @@  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;
@@ -414,8 +416,10 @@  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)