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ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug

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struct acpi_scan_handler has a detach callback that is used to remove
a driver when a bus is changed. When interacting with an eject-request,
the detach callback is called before _EJ0.

This means the ACPI processor driver can't use _STA to determine if a
CPU has been made not-present, or some of the other _STA bits have been
changed. acpi_processor_remove() needs to know the value of _STA after
_EJ0 has been called.

Add a post_eject callback to struct acpi_scan_handler. This is called
after acpi_scan_hot_remove() has successfully called _EJ0. Because
acpi_scan_check_and_detach() also clears the handler pointer,
it needs to be told if the caller will go on to call
acpi_bus_post_eject(), so that acpi_device_clear_enumerated()
and clearing the handler pointer can be deferred.
An extra flag is added to flags field introduced in the previous
patch to achieve this.

Signed-off-by: James Morse <james.morse@arm.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>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240529133446.28446-11-Jonathan.Cameron@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
James Morse 2024-05-29 14:34:37 +01:00 committed by Catalin Marinas
parent 1859a671bd
commit 3b9d0a78ae
3 changed files with 30 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
drivers/acpi/acpi_processor.c
View file

@ -475,7 +475,7 @@ static int acpi_processor_add(struct acpi_device *device,
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* Removal */
static void acpi_processor_remove(struct acpi_device *device)
static void acpi_processor_post_eject(struct acpi_device *device)
{
struct acpi_processor *pr;
@ -643,7 +643,7 @@ static struct acpi_scan_handler processor_handler = {
.ids = processor_device_ids,
.attach = acpi_processor_add,
#ifdef CONFIG_ACPI_HOTPLUG_CPU
.detach = acpi_processor_remove,
.post_eject = acpi_processor_post_eject,
#endif
.hotplug = {
.enabled = true,

30
drivers/acpi/scan.c
View file

@ -244,6 +244,7 @@ static int acpi_scan_try_to_offline(struct acpi_device *device)
}
#define ACPI_SCAN_CHECK_FLAG_STATUS BIT(0)
#define ACPI_SCAN_CHECK_FLAG_EJECT BIT(1)
static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p)
{
@ -272,8 +273,6 @@ static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p)
if (handler) {
if (handler->detach)
handler->detach(adev);
adev->handler = NULL;
} else {
device_release_driver(&adev->dev);
}
@ -283,6 +282,28 @@ static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p)
*/
acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
adev->flags.initialized = false;
/* For eject this is deferred to acpi_bus_post_eject() */
if (!(flags & ACPI_SCAN_CHECK_FLAG_EJECT)) {
adev->handler = NULL;
acpi_device_clear_enumerated(adev);
}
return 0;
}
static int acpi_bus_post_eject(struct acpi_device *adev, void *not_used)
{
struct acpi_scan_handler *handler = adev->handler;
acpi_dev_for_each_child_reverse(adev, acpi_bus_post_eject, NULL);
if (handler) {
if (handler->post_eject)
handler->post_eject(adev);
adev->handler = NULL;
}
acpi_device_clear_enumerated(adev);
return 0;
@ -300,6 +321,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
acpi_handle handle = device->handle;
unsigned long long sta;
acpi_status status;
uintptr_t flags = ACPI_SCAN_CHECK_FLAG_EJECT;
if (device->handler && device->handler->hotplug.demand_offline) {
if (!acpi_scan_is_offline(device, true))
@ -312,7 +334,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
acpi_handle_debug(handle, "Ejecting\n");
acpi_bus_trim(device);
acpi_scan_check_and_detach(device, (void *)flags);
acpi_evaluate_lck(handle, 0);
/*
@ -335,6 +357,8 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
} else if (sta & ACPI_STA_DEVICE_ENABLED) {
acpi_handle_warn(handle,
"Eject incomplete - status 0x%llx\n", sta);
} else {
acpi_bus_post_eject(device, NULL);
}
return 0;

1
include/acpi/acpi_bus.h
View file

@ -134,6 +134,7 @@ struct acpi_scan_handler {
bool (*match)(const char *idstr, const struct acpi_device_id **matchid);
int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id);
void (*detach)(struct acpi_device *dev);
void (*post_eject)(struct acpi_device *dev);
void (*bind)(struct device *phys_dev);
void (*unbind)(struct device *phys_dev);
struct acpi_hotplug_profile hotplug;