From 3b9d0a78aeda194994892f7c42f6ca5feb45eadd Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:37 +0100 Subject: [PATCH] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug 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 Reviewed-by: Gavin Shan Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-11-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 4 ++-- drivers/acpi/scan.c | 30 +++++++++++++++++++++++++++--- include/acpi/acpi_bus.h | 1 + 3 files changed, 30 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index f0b7a789f0a1..64e10bad8072 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -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, diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 4d649ce5876f..0aa20623525a 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -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; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 1a4dfd7a1c4a..05ca49478537 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -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;