| Message ID | Zbp5xzmFhKDAgHws@shell.armlinux.org.uk (mailing list archive) |
|---|---|
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpu hotplug | expand |
Hi > On 31 Jan 2024, at 15:49, Russell King <rmk+kernel@armlinux.org.uk> wrote: > > From: James Morse <james.morse@arm.com> > > Today the ACPI enumeration code 'visits' all devices that are present. > > This is a problem for arm64, where CPUs are always present, but not > always enabled. When a device-check occurs because the firmware-policy > has changed and a CPU is now enabled, the following error occurs: > | acpi ACPI0007:48: Enumeration failure > > This is ultimately because acpi_dev_ready_for_enumeration() returns > true for a device that is not enabled. The ACPI Processor driver > will not register such CPUs as they are not 'decoding their resources'. > > ACPI allows a device to be functional instead of maintaining the > present and enabled bit, but we can't simply check the enabled bit > for all devices since firmware can be buggy. > > If ACPI indicates that the device is present and enabled, then all well > and good, we can enumate it. However, if the device is present and not enumerate > enabled, then we also check whether the device is a processor device > to limit the impact of this new check to just processor devices. > > This avoids enumerating present && functional processor devices that > are not enabled. > > Signed-off-by: James Morse <james.morse@arm.com> > Co-developed-by: Rafael J. Wysocki <rjw@rjwysocki.net> > Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> > --- > Changes since RFC v2: > * Incorporate comment suggestion by Gavin Shan. > Changes since RFC v3: > * Fixed "sert" typo. > Changes since RFC v3 (smaller series): > * Restrict checking the enabled bit to processor devices, update > commit comments. > * Use Rafael's suggestion in > https://lore.kernel.org/r/5760569.DvuYhMxLoT@kreacher > * Updated with a fix - see: > https://lore.kernel.org/all/Zbe8WQRASx6D6RaG@shell.armlinux.org.uk/ > --- > drivers/acpi/acpi_processor.c | 11 +++++++++ > drivers/acpi/device_pm.c | 2 +- > drivers/acpi/device_sysfs.c | 2 +- > drivers/acpi/internal.h | 4 ++- > drivers/acpi/property.c | 2 +- > drivers/acpi/scan.c | 46 +++++++++++++++++++++++++++-------- > 6 files changed, 53 insertions(+), 14 deletions(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index 4fe2ef54088c..cf7c1cca69dd 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -626,6 +626,17 @@ static struct acpi_scan_handler processor_handler = { > }, > }; > > +bool acpi_device_is_processor(const struct acpi_device *adev) > +{ > + if (adev->device_type == ACPI_BUS_TYPE_PROCESSOR) > + return true; > + > + if (adev->device_type != ACPI_BUS_TYPE_DEVICE) > + return false; > + > + return acpi_scan_check_handler(adev, &processor_handler); > +} > + > static int acpi_processor_container_attach(struct acpi_device *dev, > const struct acpi_device_id *id) > { > diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c > index 3b4d048c4941..e3c80f3b3b57 100644 > --- a/drivers/acpi/device_pm.c > +++ b/drivers/acpi/device_pm.c > @@ -313,7 +313,7 @@ int acpi_bus_init_power(struct acpi_device *device) > return -EINVAL; > > device->power.state = ACPI_STATE_UNKNOWN; > - if (!acpi_device_is_present(device)) { > + if (!acpi_dev_ready_for_enumeration(device)) { > device->flags.initialized = false; > return -ENXIO; > } > diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c > index 23373faa35ec..a0256d2493a7 100644 > --- a/drivers/acpi/device_sysfs.c > +++ b/drivers/acpi/device_sysfs.c > @@ -141,7 +141,7 @@ static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalia > struct acpi_hardware_id *id; > > /* Avoid unnecessarily loading modules for non present devices. */ > - if (!acpi_device_is_present(acpi_dev)) > + if (!acpi_dev_ready_for_enumeration(acpi_dev)) > return 0; > > /* > diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h > index 6588525c45ef..1bc8b6db60c5 100644 > --- a/drivers/acpi/internal.h > +++ b/drivers/acpi/internal.h > @@ -62,6 +62,8 @@ void acpi_sysfs_add_hotplug_profile(struct acpi_hotplug_profile *hotplug, > int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler, > const char *hotplug_profile_name); > void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val); > +bool acpi_scan_check_handler(const struct acpi_device *adev, > + struct acpi_scan_handler *handler); > > #ifdef CONFIG_DEBUG_FS > extern struct dentry *acpi_debugfs_dir; > @@ -121,7 +123,6 @@ int acpi_device_setup_files(struct acpi_device *dev); > void acpi_device_remove_files(struct acpi_device *dev); > void acpi_device_add_finalize(struct acpi_device *device); > void acpi_free_pnp_ids(struct acpi_device_pnp *pnp); > -bool acpi_device_is_present(const struct acpi_device *adev); > bool acpi_device_is_battery(struct acpi_device *adev); > bool acpi_device_is_first_physical_node(struct acpi_device *adev, > const struct device *dev); > @@ -133,6 +134,7 @@ int acpi_bus_register_early_device(int type); > const struct acpi_device *acpi_companion_match(const struct device *dev); > int __acpi_device_uevent_modalias(const struct acpi_device *adev, > struct kobj_uevent_env *env); > +bool acpi_device_is_processor(const struct acpi_device *adev); > > /* -------------------------------------------------------------------------- > Power Resource > diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c > index a6ead5204046..9f8d54038770 100644 > --- a/drivers/acpi/property.c > +++ b/drivers/acpi/property.c > @@ -1486,7 +1486,7 @@ static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode) > if (!is_acpi_device_node(fwnode)) > return false; > > - return acpi_device_is_present(to_acpi_device_node(fwnode)); > + return acpi_dev_ready_for_enumeration(to_acpi_device_node(fwnode)); > } > > static const void * > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index e6ed1ba91e5c..fd2e8b3a5749 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -304,7 +304,7 @@ static int acpi_scan_device_check(struct acpi_device *adev) > int error; > > acpi_bus_get_status(adev); > - if (acpi_device_is_present(adev)) { > + if (acpi_dev_ready_for_enumeration(adev)) { > /* > * This function is only called for device objects for which > * matching scan handlers exist. The only situation in which > @@ -338,7 +338,7 @@ static int acpi_scan_bus_check(struct acpi_device *adev, void *not_used) > int error; > > acpi_bus_get_status(adev); > - if (!acpi_device_is_present(adev)) { > + if (!acpi_dev_ready_for_enumeration(adev)) { > acpi_scan_device_not_enumerated(adev); > return 0; > } > @@ -1917,11 +1917,6 @@ static bool acpi_device_should_be_hidden(acpi_handle handle) > return true; > } > > -bool acpi_device_is_present(const struct acpi_device *adev) > -{ > - return adev->status.present || adev->status.functional; > -} > - > static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler, > const char *idstr, > const struct acpi_device_id **matchid) > @@ -1942,6 +1937,18 @@ static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler, > return false; > } > > +bool acpi_scan_check_handler(const struct acpi_device *adev, > + struct acpi_scan_handler *handler) > +{ > + struct acpi_hardware_id *hwid; > + > + list_for_each_entry(hwid, &adev->pnp.ids, list) > + if (acpi_scan_handler_matching(handler, hwid->id, NULL)) > + return true; > + > + return false; > +} > + > static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr, > const struct acpi_device_id **matchid) > { > @@ -2405,16 +2412,35 @@ EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies); > * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration > * @device: Pointer to the &struct acpi_device to check > * > - * Check if the device is present and has no unmet dependencies. > + * Check if the device is functional or enabled and has no unmet dependencies. > * > - * Return true if the device is ready for enumeratino. Otherwise, return false. > + * Return true if the device is ready for enumeration. Otherwise, return false. > */ > bool acpi_dev_ready_for_enumeration(const struct acpi_device *device) > { > if (device->flags.honor_deps && device->dep_unmet) > return false; > > - return acpi_device_is_present(device); > + /* > + * ACPI 6.5's 6.3.7 "_STA (Device Status)" allows firmware to return > + * (!present && functional) for certain types of devices that should be > + * enumerated. Note that the enabled bit should not be set unless the > + * present bit is set. > + * > + * However, limit this only to processor devices to reduce possible > + * regressions with firmware. > + */ > + if (!device->status.present) > + return device->status.functional; > + > + /* > + * Fast path - if enabled is set, avoid the more expensive test to > + * check whether this device is a processor. > + */ > + if (device->status.enabled) > + return true; > + > + return !acpi_device_is_processor(device); Otherwise, feel free to add: Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Tested-by: Miguel Luis <miguel.luis@oracle.com> Thanks Miguel > } > EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration); > > -- > 2.30.2 > >