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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>2024-01-08 12:37:54 +0000
commitcde838f1b530379b01880c6dd0be27283ccab02c (patch)
tree0237d86488c147588427b3e0c98b8e8416ac5e9f
parent412c3e5f94945293da12d6fcb279c9ea389ad29d (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 19fceb3ec4e2..b7a94c1348b0 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_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)