diff options
| author | James Morse <james.morse@arm.com> | 2021-07-02 16:48:41 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2023-10-23 10:05:41 +0100 |
| commit | ec9d76d28b7ba0386d89d71ac4512841630ad6c7 (patch) | |
| tree | f42b8e4d42f0c06493bd57596535de1a19a98666 | |
| parent | dd118968bb3f521daafa5c45280d0e266acf3251 (diff) | |
ACPI: Check _STA present bit before making CPUs not present
When called acpi_processor_post_eject() unconditionally make a CPU
not-present and unregisters it.
To add support for AML events where the CPU has become disabled, but
remains present, the _STA method should be checked before calling
acpi_processor_remove().
Rename acpi_processor_post_eject() acpi_processor_remove_possible(), and
check the _STA before calling.
Adding the function prototype for arch_unregister_cpu() allows the
preprocessor guards to be removed.
After this change CPUs will remain registered and visible to
user-space as offline if buggy firmware triggers an eject-request,
but doesn't clear the corresponding _STA bits after _EJ0 has been
called.
Signed-off-by: James Morse <james.morse@arm.com>
| -rw-r--r-- | drivers/acpi/acpi_processor.c | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b6f5005985c3..19fceb3ec4e2 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -457,13 +457,12 @@ static int acpi_processor_add(struct acpi_device *device, return result; } -#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU /* Removal */ -static void acpi_processor_post_eject(struct acpi_device *device) +static void acpi_processor_make_not_present(struct acpi_device *device) { struct acpi_processor *pr; - if (!device || !acpi_driver_data(device)) + if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) return; pr = acpi_driver_data(device); @@ -501,7 +500,29 @@ static void acpi_processor_post_eject(struct acpi_device *device) free_cpumask_var(pr->throttling.shared_cpu_map); kfree(pr); } -#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */ + +static void acpi_processor_post_eject(struct acpi_device *device) +{ + struct acpi_processor *pr; + unsigned long long sta; + acpi_status status; + + if (!device) + return; + + pr = acpi_driver_data(device); + if (!pr || pr->id >= nr_cpu_ids || invalid_phys_cpuid(pr->phys_id)) + return; + + status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status)) + return; + + if (cpu_present(pr->id) && !(sta & ACPI_STA_DEVICE_PRESENT)) { + acpi_processor_make_not_present(device); + return; + } +} #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC bool __init processor_physically_present(acpi_handle handle) @@ -626,9 +647,7 @@ static const struct acpi_device_id processor_device_ids[] = { static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, -#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU .post_eject = acpi_processor_post_eject, -#endif .hotplug = { .enabled = true, }, |