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2023-10-24ACPI: processor: Only call arch_unregister_cpu() if HOTPLUG_CPU is selectedaarch64/hotplug-vcpu/v6.6-rc7James Morse
The kbuild robot points out that configurations without HOTPLUG_CPU selected can try to build acpi_processor_post_eject() without success as arch_unregister_cpu() is not defined. Check this explicitly. This will be merged into: | ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug for any subsequent posting. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: James Morse <james.morse@arm.com>
2023-10-24cpumask: Add enabled cpumask for present CPUs that can be brought onlineJames Morse
The 'offline' file in sysfs shows all offline CPUs, including those that aren't present. User-space is expected to remove not-present CPUs from this list to learn which CPUs could be brought online. CPUs can be present but not-enabled. These CPUs can't be brought online until the firmware policy changes, which comes with an ACPI notification that will register the CPUs. With only the offline and present files, user-space is unable to determine which CPUs it can try to bring online. Add a new CPU mask that shows this based on all the registered CPUs. Signed-off-by: James Morse <james.morse@arm.com>
2023-10-24ACPI: Add _OSC bits to advertise OS support for toggling CPU present/enabledJames Morse
Platform firmware can disabled a CPU, or make it not-present by making an eject-request notification, then waiting for the os to make it offline and call _EJx. After the firmware updates _STA with the new status. Not all operating systems support this. For arm64 making CPUs not-present has never been supported. For all ACPI architectures, making CPUs disabled has recently been added. Firmware can't know what the OS has support for. Add two new _OSC bits to advertise whether the OS supports the _STA enabled or present bits being toggled for CPUs. This will be important for arm64 if systems that support physical CPU hotplug ever appear as arm64 linux doesn't currently support this, so firmware shouldn't try. Advertising this support to firmware is useful for cloud orchestrators to know whether they can scale a particular VM by adding CPUs. Signed-off-by: James Morse <james.morse@arm.com> --- I'm assuming ia64 with physical hotplug machines once existed, and that Loongarch machines with support for this don't.
2023-10-24arm64: document virtual CPU hotplug's expectationsJames Morse
Add a description of physical and virtual CPU hotplug, explain the differences and elaborate on what is required in ACPI for a working virtual hotplug system. Signed-off-by: James Morse <james.morse@arm.com>
2023-10-24ACPI: add support to register CPUs based on the _STA enabled bitJames Morse
acpi_processor_get_info() registers all present CPUs. Registering a CPU is what creates the sysfs entries and triggers the udev notifications. arm64 virtual machines that support 'virtual cpu hotplug' use the enabled bit to indicate whether the CPU can be brought online, as the existing ACPI tables require all hardware to be described and present. If firmware describes a CPU as present, but disabled, skip the registration. Such CPUs are present, but can't be brought online for whatever reason. (e.g. firmware/hypervisor policy). Once firmware sets the enabled bit, the CPU can be registered and brought online by user-space. Online CPUs, or CPUs that are missing an _STA method must always be registered. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24arm64: psci: Ignore DENIED CPUsJean-Philippe Brucker
When a CPU is marked as disabled, but online capable in the MADT, PSCI applies some firmware policy to control when it can be brought online. PSCI returns DENIED to a CPU_ON request if this is not currently permitted. The OS can learn the current policy from the _STA enabled bit. Handle the PSCI DENIED return code gracefully instead of printing an error. See https://developer.arm.com/documentation/den0022/f/?lang=en page 58. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> [ morse: Rewrote commit message ] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2 * Add specification reference * Use EPERM rather than EPROBE_DEFER
2023-10-24irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUsJames Morse
To support virtual CPU hotplug, ACPI has added an 'online capable' bit to the MADT GICC entries. This indicates a disabled CPU entry may not be possible to online via PSCI until firmware has set enabled bit in _STA. What about the redistributor in the GICC entry? ACPI doesn't want to say. Assume the worst: When a redistributor is described in the GICC entry, but the entry is marked as disabled at boot, assume the redistributor is inaccessible. The GICv3 driver doesn't support late online of redistributors, so this means the corresponding CPU can't be brought online either. Clear the possible and present bits. Systems that want CPU hotplug in a VM can ensure their redistributors are always-on, and describe them that way with a GICR entry in the MADT. When mapping redistributors found via GICC entries, handle the case where the arch code believes the CPU is present and possible, but it does not have an accessible redistributor. Print a warning and clear the present and possible bits. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> ---- Disabled but online-capable CPUs cause this message to be printed if their redistributors are described via GICC: | GICv3: CPU 3's redistributor is inaccessible: this CPU can't be brought online If ACPI's _STA tries to make the cpu present later, this message is printed: | Changing CPU present bit is not supported Changes since RFC v2: * use gicc->flags & (ACPI_MADT_ENABLED | ACPI_MADT_GICC_CPU_CAPABLE)
2023-10-24irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc()James Morse
gic_acpi_match_gicc() is only called via gic_acpi_count_gicr_regions(). It should only count the number of enabled redistributors, but it also tries to sanity check the GICC entry, currently returning an error if the Enabled bit is set, but the gicr_base_address is zero. Adding support for the online-capable bit to the sanity check complicates it, for no benefit. The existing check implicitly depends on gic_acpi_count_gicr_regions() previous failing to find any GICR regions (as it is valid to have gicr_base_address of zero if the redistributors are described via a GICR entry). Instead of complicating the check, remove it. Failures that happen at this point cause the irqchip not to register, meaning no irqs can be requested. The kernel grinds to a panic() pretty quickly. Without the check, MADT tables that exhibit this problem are still caught by gic_populate_rdist(), which helpfully also prints what went wrong: | CPU4: mpidr 100 has no re-distributor! Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24ACPICA: Add new MADT GICC flags fieldsJames Morse
Add the new flag field to the MADT's GICC structure. 'Online Capable' indicates a disabled CPU can be enabled later. See ACPI specification 6.5 Tabel 5.37: GICC CPU Interface Flags. Signed-off-by: James Morse <james.morse@arm.com> --- This patch probably needs to go via the upstream acpica project, but is included here so the feature can be tested. If the ACPICA header files are updated before merging this patch set, this patch will need to be dropped. Changes since RFC v2: * Add ACPI specification reference.
2023-10-24arm64: acpi: Move get_cpu_for_acpi_id() to a headerJames Morse
ACPI identifies CPUs by UID. get_cpu_for_acpi_id() maps the ACPI UID to the linux CPU number. The helper to retrieve this mapping is only available in arm64's numa code. Move it to live next to get_acpi_id_for_cpu(). Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24LoongArch: Use the __weak version of arch_unregister_cpu()James Morse
LoongArch provides its own arch_unregister_cpu(). This clears the hotpluggable flag, then unregisters the CPU. It isn't necessary to clear the hotpluggable flag when unregistering a cpu. unregister_cpu() writes NULL to the percpu cpu_sys_devices pointer, meaning cpu_is_hotpluggable() will return false, as get_cpu_device() has returned NULL. Remove arch_unregister_cpu() and use the __weak version. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24ACPI: Warn when the present bit changes but the feature is not enabledJames Morse
ACPI firmware can trigger the events to add and remove CPUs, but the OS may not support this. Print an error message when this happens. This gives early warning on arm64 systems that don't support CONFIG_ACPI_HOTPLUG_PRESENT_CPU, as making CPUs not present has side effects for other parts of the system. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Update commit message with suggestion from Gavin Shan
2023-10-24ACPI: Check _STA present bit before making CPUs not presentJames Morse
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>
2023-10-24ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplugJames Morse
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_bus_trim_one() 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. The existing not-used pointer is used for this. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Joanthan Cameron <Jonathan.Cameron@huawei.com>
2023-10-24ACPI: Rename acpi_processor_hotadd_init and remove pre-processor guardsJames Morse
acpi_processor_hotadd_init() will make a CPU present by mapping it based on its hardware id. 'hotadd_init' is ambiguous once there are two different behaviours for cpu hotplug. This is for toggling the _STA present bit. Subsequent patches will add support for toggling the _STA enabled bit, named acpi_processor_make_enabled(). Rename it acpi_processor_make_present() to make it clear this is for CPUs that were not previously present. Expose the function prototypes it uses to allow the preprocessor guards to be removed. The IS_ENABLED() check will let the compiler dead-code elimination pass remove this if it isn't going to be used. Signed-off-by: James Morse <james.morse@arm.com>
2023-10-24ACPI: Move acpi_bus_trim_one() before acpi_scan_hot_remove()James Morse
A subsequent patch will change acpi_scan_hot_remove() to call acpi_bus_trim_one() instead of acpi_bus_trim(), meaning it can no longer rely on the prototype in the header file. Move these functions further up the file. No change in behaviour. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24drivers: base: Implement weak arch_unregister_cpu()James Morse
Add arch_unregister_cpu() to allow the ACPI machinery to call unregister_cpu(). This is enough for arm64, riscv and loongarch, but needs to be overridden by x86 and ia64 who need to do more work. CC: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: James Morse <james.morse@arm.com> --- Changes since v1: * Added CONFIG_HOTPLUG_CPU ifdeffery around unregister_cpu Changes since RFC v2: * Move earlier in the series
2023-10-24ACPI: Rename ACPI_HOTPLUG_CPU to include 'present'James Morse
The code behind ACPI_HOTPLUG_CPU allows a not-present CPU to become present. This isn't the only use of HOTPLUG_CPU. On arm64 and riscv CPUs can be taken offline as a power saving measure. On arm64 an offline CPU may be disabled by firmware, preventing it from being brought back online, but it remains present throughout. Adding code to prevent user-space trying to online these disabled CPUs needs some additional terminology. Rename the Kconfig symbol CONFIG_ACPI_HOTPLUG_PRESENT_CPU to reflect that it makes possible CPUs present. HOTPLUG_CPU is untouched as this is only about the ACPI mechanism. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Add Loongarch update
2023-10-24ACPI: processor: Register all CPUs from acpi_processor_get_info()James Morse
To allow ACPI to skip the call to arch_register_cpu() when the _STA value indicates the CPU can't be brought online right now, move the arch_register_cpu() call into acpi_processor_get_info(). Systems can still be booted with 'acpi=off', or not include an ACPI description at all. For these, the CPUs continue to be registered by cpu_dev_register_generic(). This moves the CPU register logic back to a subsys_initcall(), while the memory nodes will have been registered earlier. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Fixup comment in acpi_processor_get_info() (Gavin Shan) * Add comment in cpu_dev_register_generic() (Gavin Shan)
2023-10-24ACPI: processor: Register CPUs that are online, but not described in the DSDTJames Morse
ACPI has two descriptions of CPUs, one in the MADT/APIC table, the other in the DSDT. Both are required. (ACPI 6.5's 8.4 "Declaring Processors" says "Each processor in the system must be declared in the ACPI namespace"). Having two descriptions allows firmware authors to get this wrong. If CPUs are described in the MADT/APIC, they will be brought online early during boot. Once the register_cpu() calls are moved to ACPI, they will be based on the DSDT description of the CPUs. When CPUs are missing from the DSDT description, they will end up online, but not registered. Add a helper that runs after acpi_init() has completed to register CPUs that are online, but weren't found in the DSDT. Any CPU that is registered by this code triggers a firmware-bug warning and kernel taint. Qemu TCG only describes the first CPU in the DSDT, unless cpu-hotplug is configured. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24ACPI: processor: Add support for processors described as container packagesJames Morse
ACPI has two ways of describing processors in the DSDT. Either as a device object with HID ACPI0007, or as a type 'C' package inside a Processor Container. The ACPI processor driver probes CPUs described as devices, but not those described as packages. Duplicate descriptions are not allowed, the ACPI processor driver already parses the UID from both devices and containers. acpi_processor_get_info() returns an error if the UID exists twice in the DSDT. The missing probe for CPUs described as packages creates a problem for moving the cpu_register() calls into the acpi_processor driver, as CPUs described like this don't get registered, leading to errors from other subsystems when they try to add new sysfs entries to the CPU node. (e.g. topology_sysfs_init()'s use of topology_add_dev() via cpuhp) To fix this, parse the processor container and call acpi_processor_add() for each processor that is discovered like this. The processor container handler is added with acpi_scan_add_handler(), so no detach call will arrive. Qemu TCG describes CPUs using packages in a processor container. Signed-off-by: James Morse <james.morse@arm.com>
2023-10-24ACPI: Only enumerate enabled (or functional) devicesJames Morse
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'. Change acpi_dev_ready_for_enumeration() to also check the enabled bit. ACPI allows a device to be functional instead of maintaining the present and enabled bit. Make this behaviour an explicit check with a reference to the spec, and then check the present and enabled bits. This is needed to avoid enumerating present && functional devices that are not enabled. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- If this change causes problems on deployed hardware, I suggest an arch opt-in: ACPI_IGNORE_STA_ENABLED, that causes acpi_dev_ready_for_enumeration() to only check the present bit. Changes since RFC v2: * Incorporate comment suggestion by Gavin Shan. Other review comments from Jonathan Cameron not yet addressed.
2023-10-24arch_topology: Make register_cpu_capacity_sysctl() tolerant to late CPUsJames Morse
register_cpu_capacity_sysctl() adds a property to sysfs that describes the CPUs capacity. This is done from a subsys_initcall() that assumes all possible CPUs are registered. With CPU hotplug, possible CPUs aren't registered until they become present, (or for arm64 enabled). This leads to messages during boot: | register_cpu_capacity_sysctl: too early to get CPU1 device! and once these CPUs are added to the system, the file is missing. Move this to a cpuhp callback, so that the file is created once CPUs are brought online. This covers CPUs that are added late by mechanisms like hotplug. One observable difference is the file is now missing for offline CPUs. Signed-off-by: James Morse <james.morse@arm.com> --- If the offline CPUs thing is a problem for the tools that consume this value, we'd need to move cpu_capacity to be part of cpu.c's common_cpu_attr_groups.
2023-10-24riscv: Switch over to GENERIC_CPU_DEVICESJames Morse
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be overridden by the arch code, switch over to this to allow common code to choose when the register_cpu() call is made. This allows topology_init() to be removed. This is an intermediate step to the logic being moved to drivers/acpi, where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Add note about initialisation order change.
2023-10-24LoongArch: Switch over to GENERIC_CPU_DEVICESJames Morse
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be overridden by the arch code, switch over to this to allow common code to choose when the register_cpu() call is made. This allows topology_init() to be removed. This is an intermediate step to the logic being moved to drivers/acpi, where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. This is a subtle change. Originally: - on boot, topology_init() would have marked present CPUs that io_master() is true for as hotplug-incapable. - if a CPU is hotplugged that is an io_master(), it can later be hot-unplugged. The new behaviour is that any CPU that io_master() is true for will now always be marked as hotplug-incapable, thus even if it was hotplugged, it can no longer be hot-unplugged. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Explain the change in behaviour in the patch description (highlighted by Jonathan Cameron - thanks.) Add note about initialisation order change.
2023-10-24x86/topology: Switch over to GENERIC_CPU_DEVICESJames Morse
Now that GENERIC_CPU_DEVICES calls arch_register_cpu(), which can be overridden by the arch code, switch over to this to allow common code to choose when the register_cpu() call is made. x86's struct cpus come from struct x86_cpu, which has no other members or users. Remove this and use the version defined by common code. This is an intermediate step to the logic being moved to drivers/acpi, where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> ---- Changes since RFC: * Fixed the second copy of arch_register_cpu() used for non-hotplug Changes since RFC v2: * Remove duplicate of the weak generic arch_register_cpu(), spotted by Jonathan Cameron. Add note about initialisation order change.
2023-10-24x86: intel_epb: Don't rely on link orderJames Morse
intel_epb_init() is called as a subsys_initcall() to register cpuhp callbacks. The callbacks make use of get_cpu_device() which will return NULL unless register_cpu() has been called. register_cpu() is called from topology_init(), which is also a subsys_initcall(). This is fragile. Moving the register_cpu() to a different subsys_initcall() leads to a NULL dereference during boot. Make intel_epb_init() a late_initcall(), user-space can't provide a policy before this point anyway. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- subsys_initcall_sync() would be an option, but moving the register_cpu() calls into ACPI also means adding a safety net for CPUs that are online but not described properly by firmware. This lives in subsys_initcall_sync().
2023-10-24ia64/topology: Switch over to GENERIC_CPU_DEVICESJames Morse
ia64 has its own arch specific data structure for cpus: struct ia64_cpu. This has one member, making ia64's cpu_devices the same as that provided be GENERIC_CPU_DEVICES. ia64 craetes a percpu struct ia64_cpu called cpu_devices, which has no users. Instead it uses the struct ia64_cpu named sysfs_cpus allocated at boot. Remove the arch specific structure allocation and initialisation. ia64's arch_register_cpu() now overrides the weak version from GENERIC_CPU_DEVICES, and uses the percpu cpu_devices defined by core code. All uses of sysfs_cpus are changed to use the percpu cpu_devices. This is an intermediate step to the logic being moved to drivers/acpi, where GENERIC_CPU_DEVICES will do the work when booting with acpi=off. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Add note about initialisation order change.
2023-10-24arm64: setup: Switch over to GENERIC_CPU_DEVICES using arch_register_cpu()James Morse
To allow ACPI's _STA value to hide CPUs that are present, but not available to online right now due to VMM or firmware policy, the register_cpu() call needs to be made by the ACPI machinery when ACPI is in use. This allows it to hide CPUs that are unavailable from sysfs. Switching to GENERIC_CPU_DEVICES is an intermediate step to allow all five ACPI architectures to be modified at once. Switch over to GENERIC_CPU_DEVICES, and provide an arch_register_cpu() that populates the hotpluggable flag. arch_register_cpu() is also the interface the ACPI machinery expects. The struct cpu in struct cpuinfo_arm64 is never used directly, remove it to use the one GENERIC_CPU_DEVICES provides. This changes the CPUs visible in sysfs from possible to present, but on arm64 smp_prepare_cpus() ensures these are the same. This patch also has the effect of moving the registration of CPUs from subsys to driver core initialisation, prior to any initcalls running. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Add note about initialisation order change.
2023-10-24drivers: base: Print a warning instead of panic() when register_cpu() failsJames Morse
loongarch, mips, parisc, riscv and sh all print a warning if register_cpu() returns an error. Architectures that use GENERIC_CPU_DEVICES call panic() instead. Errors in this path indicate something is wrong with the firmware description of the platform, but the kernel is able to keep running. Downgrade this to a warning to make it easier to debug this issue. This will allow architectures that switching over to GENERIC_CPU_DEVICES to drop their warning, but keep the existing behaviour. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24drivers: base: remove unnecessary call to register_cpu_under_node()Russell King (Oracle)
Since "drivers: base: Move cpu_dev_init() after node_dev_init()", we can remove some redundant code. node_dev_init() will walk through the nodes calling register_one_node() on each. This will trickle down to __register_one_node() which walks all present CPUs, calling register_cpu_under_node() on each. register_cpu_under_node() will call get_cpu_device(cpu) for each, which will return NULL until the CPU is registered using register_cpu(). This now happens _after_ node_dev_init(). Therefore, calling register_cpu_under_node() from __register_one_node() becomes a no-op, and can be removed. Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24drivers: base: Move cpu_dev_init() after node_dev_init()James Morse
NUMA systems require the node descriptions to be ready before CPUs are registered. This is so that the node symlinks can be created in sysfs. Currently no NUMA platform uses GENERIC_CPU_DEVICES, meaning that CPUs are registered by arch code, instead of cpu_dev_init(). Move cpu_dev_init() after node_dev_init() so that NUMA architectures can use GENERIC_CPU_DEVICES. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Note: Jonathan's comment still needs addressing - see https://lore.kernel.org/r/20230914121612.00006ac7@Huawei.com
2023-10-24drivers: base: Allow parts of GENERIC_CPU_DEVICES to be overriddenJames Morse
Architectures often have extra per-cpu work that needs doing before a CPU is registered, often to determine if a CPU is hotpluggable. To allow the ACPI architectures to use GENERIC_CPU_DEVICES, move the cpu_register() call into arch_register_cpu(), which is made __weak so architectures with extra work can override it. This aligns with the way x86, ia64 and loongarch register hotplug CPUs when they become present. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC: * Dropped __init from x86/ia64 arch_register_cpu() Changes since RFC v2: * Dropped unnecessary Loongarch asm/cpu.h changes
2023-10-24drivers: base: Use present CPUs in GENERIC_CPU_DEVICESJames Morse
Three of the five ACPI architectures create sysfs entries using register_cpu() for present CPUs, whereas arm64, riscv and all GENERIC_CPU_DEVICES do this for possible CPUs. Registering a CPU is what causes them to show up in sysfs. It makes very little sense to register all possible CPUs. Registering a CPU is what triggers the udev notifications allowing user-space to react to newly added CPUs. To allow all five ACPI architectures to use GENERIC_CPU_DEVICES, change it to use for_each_present_cpu(). Making the ACPI architectures use GENERIC_CPU_DEVICES is a pre-requisite step to centralise their cpu_register() logic, before moving it into the ACPI processor driver. When ACPI is disabled this work would be done by cpu_dev_register_generic(). Of the ACPI architectures that register possible CPUs, arm64 and riscv do not support making possible CPUs present as they use the weak 'always fails' version of arch_register_cpu(). Only two of the eight architectures that use GENERIC_CPU_DEVICES have a distinction between present and possible CPUs. The following architectures use GENERIC_CPU_DEVICES but are not SMP, so possible == present: * m68k * microblaze * nios2 The following architectures use GENERIC_CPU_DEVICES and consider possible == present: * csky: setup_smp() * processor_probe() sets possible for all CPUs and present for all CPUs except the boot cpu, which will have been done by init/main.c::start_kernel(). um appears to be a subarchitecture of x86. The remaining architecture using GENERIC_CPU_DEVICES are: * openrisc and hexagon: where smp_init_cpus() makes all CPUs < NR_CPUS possible, whereas smp_prepare_cpus() only makes CPUs < setup_max_cpus present. After this change, openrisc and hexagon systems that use the max_cpus command line argument would not see the other CPUs present in sysfs. This should not be a problem as these CPUs can't bre brought online as _cpu_up() checks cpu_present(). After this change, only CPUs which are present appear in sysfs. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24ACPI: Move ACPI_HOTPLUG_CPU to be disabled on arm64 and riscvJames Morse
Neither arm64 nor riscv support physical hotadd of CPUs that were not present at boot. For arm64 much of the platform description is in static tables which do not have update methods. arm64 does support HOTPLUG_CPU, which is backed by a firmware interface to turn CPUs on and off. acpi_processor_hotadd_init() and acpi_processor_remove() are for adding and removing CPUs that were not present at boot. arm64 systems that do this are not supported as there is currently insufficient information in the platform description. (e.g. did the GICR get removed too?) arm64 currently relies on the MADT enabled flag check in map_gicc_mpidr() to prevent CPUs that were not described as present at boot from being added to the system. Similarly, riscv relies on the same check in map_rintc_hartid(). Both architectures also rely on the weak 'always fails' definitions of acpi_map_cpu() and arch_register_cpu(). Subsequent changes will redefine ACPI_HOTPLUG_CPU as making possible CPUs present. Neither arm64 nor riscv support this. Disable ACPI_HOTPLUG_CPU for arm64 and riscv by removing 'default y' and selecting it on the other three ACPI architectures. This allows the weak definitions of some symbols to be removed. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC: * Expanded conditions to avoid ACPI_HOTPLUG_CPU being enabled when HOTPLUG_CPU isn't.
2023-10-24arm64, irqchip/gic-v3, ACPI: Move MADT GICC enabled check into a helperJames Morse
ACPI, irqchip and the architecture code all inspect the MADT enabled bit for a GICC entry in the MADT. The addition of an 'online capable' bit means all these sites need updating. Move the current checks behind a helper to make future updates easier. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> --- Changes since RFC v2: * Remove unnecessary parens * Moved earlier in series
2023-10-24ACPI: Rename acpi_scan_device_not_present() to be about enumerationJames Morse
acpi_scan_device_not_present() is called when a device in the hierarchy is not available for enumeration. Historically enumeration was only based on whether the device was present. To add support for only enumerating devices that are both present and enabled, this helper should be renamed. It was only ever about enumeration, rename it acpi_scan_device_not_enumerated(). No change in behaviour is intended. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24ACPI: Use the acpi_device_is_present() helper in more placesJames Morse
acpi_device_is_present() checks the present or functional bits from the cached copy of _STA. A few places open-code this check. Use the helper instead to improve readability. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Miguel Luis <miguel.luis@oracle.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-24parisc: simplify smp_prepare_boot_cpu()Russell King (Oracle)
smp_prepare_boot_cpu() reads the cpuid of the first CPU, printing a message to state which processor booted, and setting it online and present. This cpuid is retrieved from per_cpu(cpu_data, 0).cpuid, which is initialised in arch/parisc/kernel/processor.c:processor_probe() thusly: p = &per_cpu(cpu_data, cpuid); ... p->cpuid = cpuid; /* save CPU id */ Consequently, the cpuid retrieved seems to be guaranteed to also be zero, meaning that the message printed in this boils down to: pr_info("SMP: bootstrap CPU ID is 0\n"); Moreover, since kernel/cpu.c::boot_cpu_init() already sets CPU 0 to be present and online, there is no need to do this again in smp_prepare_boot_cpu(). Remove this code, and simplify the printk(). Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2023-10-22Linux 6.6-rc7Linus Torvalds
2023-10-22Merge tag 'phy-fixes-6.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy Pull phy fixes from Vinod Koul: - mapphone-mdm6600 runtime pm & pinctrl handling fixes - Qualcomm qmp usb pcs register fixes, qmp pcie register size warning fix, m31 fixes for wrong pointer in PTR_ERR and dropping wrong vreg check, qmp combo fix for 8550 power config register - realtek usb fix for debugfs_create_dir() and kconfig dependency * tag 'phy-fixes-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy: phy: realtek: Realtek PHYs should depend on ARCH_REALTEK phy: qualcomm: Fix typos in comments phy: qcom-qmp-combo: initialize PCS_USB registers phy: qcom-qmp-combo: Square out 8550 POWER_STATE_CONFIG1 phy: qcom: m31: Remove unwanted qphy->vreg is NULL check phy: realtek: usb: Drop unnecessary error check for debugfs_create_dir() phy: qcom: phy-qcom-m31: change m31_ipq5332_regs to static phy: qcom: phy-qcom-m31: fix wrong pointer pass to PTR_ERR() dt-bindings: phy: qcom,ipq8074-qmp-pcie: fix warning regarding reg size phy: qcom-qmp-usb: split PCS_USB init table for sc8280xp and sa8775p phy: qcom-qmp-usb: initialize PCS_USB registers phy: mapphone-mdm6600: Fix pinctrl_pm handling for sleep pins phy: mapphone-mdm6600: Fix runtime PM for remove phy: mapphone-mdm6600: Fix runtime disable on probe
2023-10-22Merge tag 'efi-fixes-for-v6.6-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: "The boot_params pointer fix uses a somewhat ugly extern struct declaration but this will be cleaned up the next cycle. - don't try to print warnings to the console when it is no longer available - fix theoretical memory leak in SSDT override handling - make sure that the boot_params global variable is set before the KASLR code attempts to hash it for 'randomness' - avoid soft lockups in the memory acceptance code" * tag 'efi-fixes-for-v6.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi/unaccepted: Fix soft lockups caused by parallel memory acceptance x86/boot: efistub: Assign global boot_params variable efi: fix memory leak in krealloc failure handling x86/efistub: Don't try to print after ExitBootService()
2023-10-21Merge tag 'powerpc-6.6-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - Fix stale propagated yield_cpu in qspinlocks leading to lockups - Fix broken hugepages on some configs due to ARCH_FORCE_MAX_ORDER - Fix a spurious warning when copros are in use at exit time Thanks to Nicholas Piggin, Christophe Leroy, Nysal Jan K.A Sachin Sant, and Shrikanth Hegde. * tag 'powerpc-6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/qspinlock: Fix stale propagated yield_cpu powerpc/64s/radix: Don't warn on copros in radix__tlb_flush() powerpc/mm: Allow ARCH_FORCE_MAX_ORDER up to 12
2023-10-21Merge tag 'gpio-fixes-for-v6.6-rc7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux Pull gpio fixes from Bartosz Golaszewski: - fix interrupt handling in suspend and wakeup in gpio-vf610 - fix a bug on setting direction to output in gpio-vf610 - add a missing memset() in gpio ACPI code * tag 'gpio-fixes-for-v6.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: gpiolib: acpi: Add missing memset(0) to acpi_get_gpiod_from_data() gpio: vf610: set value before the direction to avoid a glitch gpio: vf610: mask the gpio irq in system suspend and support wakeup
2023-10-21Merge tag 'rust-fixes-6.6' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust fixes from Miguel Ojeda: - GCC build: fix bindgen build error with '-fstrict-flex-arrays' - Error module: fix the description for 'ECHILD' and fix Markdown style nit - Code docs: fix logo replacement - Docs: update docs output path - Kbuild: remove old docs output path in 'cleandocs' target * tag 'rust-fixes-6.6' of https://github.com/Rust-for-Linux/linux: rust: docs: fix logo replacement kbuild: remove old Rust docs output path docs: rust: update Rust docs output path rust: fix bindgen build error with fstrict-flex-arrays rust: error: Markdown style nit rust: error: fix the description for `ECHILD`
2023-10-21Merge tag 'sched-urgent-2023-10-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Fix a recently introduced use-after-free bug" * tag 'sched-urgent-2023-10-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/eevdf: Fix heap corruption more
2023-10-21Merge tag 'perf-urgent-2023-10-21' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events fix from Ingo Molnar: "Fix group event semantics" * tag 'perf-urgent-2023-10-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Disallow mis-matched inherited group reads
2023-10-21Merge tag 'probes-fixes-v6.6-rc6.2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probes fixes from Masami Hiramatsu: - kprobe-events: Fix kprobe events to reject if the attached symbol is not unique name because it may not the function which the user want to attach to. (User can attach a probe to such symbol using the nearest unique symbol + offset.) - selftest: Add a testcase to ensure the kprobe event rejects non unique symbol correctly. * tag 'probes-fixes-v6.6-rc6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: selftests/ftrace: Add new test case which checks non unique symbol tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols
2023-10-21Merge tag 's390-6.6-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Vasily Gorbik: - Fix IOMMU bitmap allocation in s390 PCI to avoid out of bounds access when IOMMU pages aren't a multiple of 64 - Fix kasan crashes when accessing DCSS mapping in memory holes by adding corresponding kasan zero shadow mappings - Fix a memory leak in css_alloc_subchannel in case dma_set_coherent_mask fails * tag 's390-6.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pci: fix iommu bitmap allocation s390/kasan: handle DCSS mapping in memory holes s390/cio: fix a memleak in css_alloc_subchannel
2023-10-21Merge tag 'platform-drivers-x86-v6.6-5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86 Pull x86 platform driver fixes from Hans de Goede: - Fix spurious brightness down presses on newer Asus laptop models - Fix backlight control not working on T2 Mac Pro all-in-ones - Add Armin Wolf as new maintainer for the WMI bus driver and change its status from orphaned to maintained - A few other small fixes * tag 'platform-drivers-x86-v6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: platform/mellanox: mlxbf-tmfifo: Fix a warning message apple-gmux: Hard Code max brightness for MMIO gmux platform/surface: platform_profile: Propagate error if profile registration fails platform/x86: asus-wmi: Map 0x2a code, Ignore 0x2b and 0x2c events platform/x86: asus-wmi: Only map brightness codes when using asus-wmi backlight control platform/x86: asus-wmi: Change ASUS_WMI_BRN_DOWN code from 0x20 to 0x2e platform/x86: wmi: Update MAINTAINERS entry platform/x86: msi-ec: Fix the 3rd config platform/x86: intel-uncore-freq: Conditionally create attribute for read frequency platform: mellanox: Fix a resource leak in an error handling path in probing flow