| Message ID | 20240418135412.14730-9-Jonathan.Cameron@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpu hotplug | expand |
On Thu, Apr 18, 2024 at 3:58 PM Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > > From: James Morse <james.morse@arm.com> > > 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: Joanthan 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: Jonathan Cameron <Jonathan.Cameron@huawei.com> No objections: Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > ---- > v7: > - No change. > v6: > - Switch to flags. > Russell, you hadn't signed off on this when posting last time. > Do you want to insert a suitable tag now? > v5: > - Rebase to take into account the changes to scan handling in the > meantime. > --- > 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 4e65011e706c..beb1761db579 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -471,7 +471,7 @@ 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; > > @@ -639,7 +639,7 @@ 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 1ec9677e6c2d..3ec54624664a 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -245,6 +245,7 @@ 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) > { > @@ -273,8 +274,6 @@ 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); > } > @@ -284,6 +283,28 @@ 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; > @@ -301,6 +322,7 @@ 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)) > @@ -313,7 +335,7 @@ 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); > /* > @@ -336,6 +358,8 @@ 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 e7796f373d0d..51a4b936f19e 100644 > --- a/include/acpi/acpi_bus.h > +++ b/include/acpi/acpi_bus.h > @@ -129,6 +129,7 @@ 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; > -- > 2.39.2 >
On 2024/4/18 21:54, Jonathan Cameron wrote: > From: James Morse <james.morse@arm.com> > > 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: Joanthan 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: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
On Thu, 18 Apr 2024 14:54:04 +0100 Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote: > From: James Morse <james.morse@arm.com> > > 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: Joanthan Cameron <Jonathan.Cameron@huawei.com> Gavin's earlier review showed I can't type. Fixed up by dropping this RB seeing as I signed off anyway. > 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: Jonathan Cameron <Jonathan.Cameron@huawei.com> >
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 4e65011e706c..beb1761db579 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -471,7 +471,7 @@ 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; @@ -639,7 +639,7 @@ 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 1ec9677e6c2d..3ec54624664a 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -245,6 +245,7 @@ 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) { @@ -273,8 +274,6 @@ 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); } @@ -284,6 +283,28 @@ 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; @@ -301,6 +322,7 @@ 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)) @@ -313,7 +335,7 @@ 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); /* @@ -336,6 +358,8 @@ 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 e7796f373d0d..51a4b936f19e 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -129,6 +129,7 @@ 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;