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authorJames Morse <james.morse@arm.com>2021-07-02 16:55:34 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2024-01-30 10:57:27 +0000
commita70f9123454ee5f046b5364106bdc63906437fce (patch)
tree04e11906180c9edb636531dd4bb08ea61b566f87
parent96f46409f00ed5c47a6dc9acd6684bae77294f0f (diff)
ACPI: Warn when the present bit changes but the feature is not enabled
ACPI firmware can trigger the events to add and remove CPUs, but the OS may not support this. Print an error message 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> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Tested-by: Miguel Luis <miguel.luis@oracle.com> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> Tested-by: Jianyong Wu <jianyong.wu@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Update commit message with suggestion from Gavin Shan
-rw-r--r--drivers/acpi/acpi_processor.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 77d47e6c2474..d1d33e74216c 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -189,8 +189,10 @@ static int acpi_processor_make_present(struct acpi_processor *pr)
acpi_status status;
int ret;
- if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_CPU))
+ if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_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_CPU))
+ if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_CPU)) {
+ pr_err_once("Changing CPU present bit is not supported");
return;
+ }
pr = acpi_driver_data(device);
if (pr->id >= nr_cpu_ids)