This is this remaining patches for ARM64 virtual cpu hotplug, which follows on from the previous set of 21 patches that GregKH has recently queued up, and "x86: intel_epb: Don't rely on link order" which can be found at:
https://lore.kernel.org/r/ZVyz/Ve5pPu8AWoA@shell.armlinux.org.uk
James Morse (19): ACPI: Only enumerate enabled (or functional) devices ACPI: processor: Add support for processors described as container packages ACPI: processor: Register CPUs that are online, but not described in the DSDT ACPI: processor: Register all CPUs from acpi_processor_get_info() ACPI: Rename ACPI_HOTPLUG_CPU to include 'present' ACPI: Move acpi_bus_trim_one() before acpi_scan_hot_remove() ACPI: Rename acpi_processor_hotadd_init and remove pre-processor guards ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug ACPI: Check _STA present bit before making CPUs not present ACPI: Warn when the present bit changes but the feature is not enabled arm64: acpi: Move get_cpu_for_acpi_id() to a header ACPICA: Add new MADT GICC flags fields irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs ACPI: add support to register CPUs based on the _STA enabled bit ACPI: processor: Only call arch_unregister_cpu() if HOTPLUG_CPU is selected arm64: document virtual CPU hotplug's expectations ACPI: Add _OSC bits to advertise OS support for toggling CPU present/enabled cpumask: Add enabled cpumask for present CPUs that can be brought online
Jean-Philippe Brucker (1): arm64: psci: Ignore DENIED CPUs
Russell King (Oracle) (1): ACPI: convert acpi_processor_post_eject() to use IS_ENABLED()
Documentation/arch/arm64/cpu-hotplug.rst | 79 ++++++++++++ Documentation/arch/arm64/index.rst | 1 + arch/arm64/include/asm/acpi.h | 11 ++ arch/arm64/kernel/acpi_numa.c | 11 -- arch/arm64/kernel/psci.c | 2 +- arch/arm64/kernel/smp.c | 3 +- arch/loongarch/Kconfig | 2 +- arch/loongarch/configs/loongson3_defconfig | 2 +- arch/loongarch/kernel/acpi.c | 4 +- arch/x86/Kconfig | 3 +- arch/x86/kernel/acpi/boot.c | 4 +- drivers/acpi/Kconfig | 13 +- drivers/acpi/acpi_processor.c | 141 +++++++++++++++++++-- drivers/acpi/bus.c | 16 +++ drivers/acpi/device_pm.c | 2 +- drivers/acpi/device_sysfs.c | 2 +- drivers/acpi/internal.h | 1 - drivers/acpi/property.c | 2 +- drivers/acpi/scan.c | 140 +++++++++++++------- drivers/base/cpu.c | 16 ++- drivers/irqchip/irq-gic-v3.c | 32 +++-- include/acpi/acpi_bus.h | 1 + include/acpi/actbl2.h | 1 + include/linux/acpi.h | 10 +- include/linux/cpumask.h | 25 ++++ kernel/cpu.c | 3 + 26 files changed, 421 insertions(+), 106 deletions(-) create mode 100644 Documentation/arch/arm64/cpu-hotplug.rst
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: James Morse james.morse@arm.com Signed-off-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Tested-by: Jonathan Cameron Jonathan.Cameron@huawei.com Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/device_pm.c | 2 +- drivers/acpi/device_sysfs.c | 2 +- drivers/acpi/internal.h | 1 - drivers/acpi/property.c | 2 +- drivers/acpi/scan.c | 24 ++++++++++++++---------- 5 files changed, 17 insertions(+), 14 deletions(-)
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 a34d8578b3da..ec05e40e8a96 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 253afdcf3aa9..ef5d0ae07903 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -106,7 +106,6 @@ 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); diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c index 99b4e3355435..1562e9806216 100644 --- a/drivers/acpi/property.c +++ b/drivers/acpi/property.c @@ -1419,7 +1419,7 @@ 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 083467e81415..208d9cbb9f76 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; } @@ -1913,11 +1913,6 @@ 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) @@ -2380,16 +2375,25 @@ 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 can't be sert until the present + * bit is set. + */ + if (device->status.present) + return device->status.enabled; + else + return device->status.functional; } EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
ACPI has two ways of describing processors in the DSDT. From ACPI v6.5, 5.2.12:
"Starting with ACPI Specification 6.3, the use of the Processor() object was deprecated. Only legacy systems should continue with this usage. On the Itanium architecture only, a _UID is provided for the Processor() that is a string object. This usage of _UID is also deprecated since it can preclude an OSPM from being able to match a processor to a non-enumerable device, such as those defined in the MADT. From ACPI Specification 6.3 onward, all processor objects for all architectures except Itanium must now use Device() objects with an _HID of ACPI0007, and use only integer _UID values."
Also see https://uefi.org/specs/ACPI/6.5/08_Processor_Configuration_and_Control.html#...
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 processor devices in a processor container. For more information, see build_cpus_aml() in Qemu hw/acpi/cpu.c and https://uefi.org/specs/ACPI/6.5/08_Processor_Configuration_and_Control.html#...
Signed-off-by: James Morse james.morse@arm.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 Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 4fe2ef54088c..6a542e0ce396 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -626,9 +626,31 @@ static struct acpi_scan_handler processor_handler = { }, };
+static acpi_status acpi_processor_container_walk(acpi_handle handle, + u32 lvl, + void *context, + void **rv) +{ + struct acpi_device *adev; + acpi_status status; + + adev = acpi_get_acpi_dev(handle); + if (!adev) + return AE_ERROR; + + status = acpi_processor_add(adev, &processor_device_ids[0]); + acpi_put_acpi_dev(adev); + + return status; +} + static int acpi_processor_container_attach(struct acpi_device *dev, const struct acpi_device_id *id) { + acpi_walk_namespace(ACPI_TYPE_PROCESSOR, dev->handle, + ACPI_UINT32_MAX, acpi_processor_container_walk, + NULL, NULL, NULL); + return 1; }
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 6a542e0ce396..0511f2bc10bc 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -791,6 +791,25 @@ void __init acpi_processor_init(void) acpi_pcc_cpufreq_init(); }
+static int __init acpi_processor_register_missing_cpus(void) +{ + int cpu; + + if (acpi_disabled) + return 0; + + for_each_online_cpu(cpu) { + if (!get_cpu_device(cpu)) { + pr_err_once(FW_BUG "CPU %u has no ACPI namespace description!\n", cpu); + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); + arch_register_cpu(cpu); + } + } + + return 0; +} +subsys_initcall_sync(acpi_processor_register_missing_cpus); + #ifdef CONFIG_ACPI_PROCESSOR_CSTATE /** * acpi_processor_claim_cst_control - Request _CST control from the platform.
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 12 ++++++++++++ drivers/base/cpu.c | 6 +++++- 2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 0511f2bc10bc..e7ed4730cbbe 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -314,6 +314,18 @@ static int acpi_processor_get_info(struct acpi_device *device) cpufreq_add_device("acpi-cpufreq"); }
+ /* + * Register CPUs that are present. get_cpu_device() is used to skip + * duplicate CPU descriptions from firmware. + */ + if (!invalid_logical_cpuid(pr->id) && cpu_present(pr->id) && + !get_cpu_device(pr->id)) { + int ret = arch_register_cpu(pr->id); + + if (ret) + return ret; + } + /* * Extra Processor objects may be enumerated on MP systems with * less than the max # of CPUs. They should be ignored _iff diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 47de0f140ba6..13d052bf13f4 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -553,7 +553,11 @@ static void __init cpu_dev_register_generic(void) { int i, ret;
- if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES)) + /* + * When ACPI is enabled, CPUs are registered via + * acpi_processor_get_info(). + */ + if (!IS_ENABLED(CONFIG_GENERIC_CPU_DEVICES) || !acpi_disabled) return;
for_each_present_cpu(i) {
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com confilct: arch/loongarch/configs/loongson3_defconfig Signed-off-by: liwei liwei728@huawei.com --- arch/loongarch/Kconfig | 2 +- arch/loongarch/configs/loongson3_defconfig | 2 +- arch/loongarch/kernel/acpi.c | 4 ++-- arch/x86/Kconfig | 2 +- arch/x86/kernel/acpi/boot.c | 4 ++-- drivers/acpi/Kconfig | 4 ++-- drivers/acpi/acpi_processor.c | 10 +++++----- include/linux/acpi.h | 6 +++--- 8 files changed, 17 insertions(+), 17 deletions(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 12f5fcb630a7..1b49ba42de58 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -5,7 +5,7 @@ config LOONGARCH select ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_MCFG if ACPI - select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU + select ACPI_HOTPLUG_PRESENT_CPU if ACPI_PROCESSOR && HOTPLUG_CPU select ACPI_PPTT if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI select ARCH_BINFMT_ELF_STATE diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig index 569484674f7e..ec21b2e7aae3 100644 --- a/arch/loongarch/configs/loongson3_defconfig +++ b/arch/loongarch/configs/loongson3_defconfig @@ -59,7 +59,7 @@ CONFIG_ACPI_SPCR_TABLE=y CONFIG_ACPI_TAD=y CONFIG_ACPI_DOCK=y CONFIG_ACPI_IPMI=m -CONFIG_ACPI_HOTPLUG_CPU=y +CONFIG_ACPI_HOTPLUG_PRESENT_CPU=y CONFIG_ACPI_PCI_SLOT=y CONFIG_CPU_FREQ=y CONFIG_CPU_FREQ_STAT=y diff --git a/arch/loongarch/kernel/acpi.c b/arch/loongarch/kernel/acpi.c index 23601a3a8352..5b5990765908 100644 --- a/arch/loongarch/kernel/acpi.c +++ b/arch/loongarch/kernel/acpi.c @@ -293,7 +293,7 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size) memblock_reserve(addr, size); }
-#ifdef CONFIG_ACPI_HOTPLUG_CPU +#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU
#include <acpi/processor.h>
@@ -345,4 +345,4 @@ int acpi_unmap_cpu(int cpu) } EXPORT_SYMBOL(acpi_unmap_cpu);
-#endif /* CONFIG_ACPI_HOTPLUG_CPU */ +#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */ diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e4059e24445c..caa325b45410 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -60,7 +60,7 @@ config X86 # select ACPI_LEGACY_TABLES_LOOKUP if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI - select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU + select ACPI_HOTPLUG_PRESENT_CPU if ACPI_PROCESSOR && HOTPLUG_CPU select ARCH_32BIT_OFF_T if X86_32 select ARCH_CLOCKSOURCE_INIT select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index c55c0ef47a18..8202bd2d957d 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -817,7 +817,7 @@ static void __init acpi_set_irq_model_ioapic(void) /* * ACPI based hotplug support for CPU */ -#ifdef CONFIG_ACPI_HOTPLUG_CPU +#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU #include <acpi/processor.h>
static int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid) @@ -866,7 +866,7 @@ int acpi_unmap_cpu(int cpu) return (0); } EXPORT_SYMBOL(acpi_unmap_cpu); -#endif /* CONFIG_ACPI_HOTPLUG_CPU */ +#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base) { diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 8456d48ba702..417f9f3077d2 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -305,7 +305,7 @@ config ACPI_IPMI To compile this driver as a module, choose M here: the module will be called as acpi_ipmi.
-config ACPI_HOTPLUG_CPU +config ACPI_HOTPLUG_PRESENT_CPU bool depends on ACPI_PROCESSOR && HOTPLUG_CPU select ACPI_CONTAINER @@ -399,7 +399,7 @@ config ACPI_PCI_SLOT
config ACPI_CONTAINER bool "Container and Module Devices" - default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU) + default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_PRESENT_CPU) help This driver supports ACPI Container and Module devices (IDs ACPI0004, PNP0A05, and PNP0A06). diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index e7ed4730cbbe..c8e960ff0aca 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -183,7 +183,7 @@ static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */
/* Initialization */ -#ifdef CONFIG_ACPI_HOTPLUG_CPU +#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU static int acpi_processor_hotadd_init(struct acpi_processor *pr) { unsigned long long sta; @@ -228,7 +228,7 @@ static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) { return -ENODEV; } -#endif /* CONFIG_ACPI_HOTPLUG_CPU */ +#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
static int acpi_processor_get_info(struct acpi_device *device) { @@ -461,7 +461,7 @@ static int acpi_processor_add(struct acpi_device *device, return result; }
-#ifdef CONFIG_ACPI_HOTPLUG_CPU +#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU /* Removal */ static void acpi_processor_remove(struct acpi_device *device) { @@ -505,7 +505,7 @@ static void acpi_processor_remove(struct acpi_device *device) free_cpumask_var(pr->throttling.shared_cpu_map); kfree(pr); } -#endif /* CONFIG_ACPI_HOTPLUG_CPU */ +#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
#ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC bool __init processor_physically_present(acpi_handle handle) @@ -630,7 +630,7 @@ static const struct acpi_device_id processor_device_ids[] = { static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, -#ifdef CONFIG_ACPI_HOTPLUG_CPU +#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU .detach = acpi_processor_remove, #endif .hotplug = { diff --git a/include/linux/acpi.h b/include/linux/acpi.h index b51ecc2619a0..ae879abbf51b 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -321,12 +321,12 @@ static inline int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu, } #endif
-#ifdef CONFIG_ACPI_HOTPLUG_CPU +#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU /* Arch dependent functions for cpu hotplug support */ int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id, int *pcpu); int acpi_unmap_cpu(int cpu); -#endif /* CONFIG_ACPI_HOTPLUG_CPU */ +#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr); @@ -649,7 +649,7 @@ static inline u32 acpi_osc_ctx_get_cxl_control(struct acpi_osc_context *context) #define ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS 0x0000000F
/* Enable _OST when all relevant hotplug operations are enabled */ -#if defined(CONFIG_ACPI_HOTPLUG_CPU) && \ +#if defined(CONFIG_ACPI_HOTPLUG_PRESENT_CPU) && \ defined(CONFIG_ACPI_HOTPLUG_MEMORY) && \ defined(CONFIG_ACPI_CONTAINER) #define ACPI_HOTPLUG_OST
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/scan.c | 76 ++++++++++++++++++++++----------------------- 1 file changed, 38 insertions(+), 38 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 208d9cbb9f76..e4db9d0c694c 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -244,6 +244,44 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) return 0; }
+static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) +{ + struct acpi_scan_handler *handler = adev->handler; + + acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL); + + adev->flags.match_driver = false; + if (handler) { + if (handler->detach) + handler->detach(adev); + + adev->handler = NULL; + } else { + device_release_driver(&adev->dev); + } + /* + * Most likely, the device is going away, so put it into D3cold before + * that. + */ + acpi_device_set_power(adev, ACPI_STATE_D3_COLD); + adev->flags.initialized = false; + acpi_device_clear_enumerated(adev); + + return 0; +} + +/** + * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects. + * @adev: Root of the ACPI namespace scope to walk. + * + * Must be called under acpi_scan_lock. + */ +void acpi_bus_trim(struct acpi_device *adev) +{ + acpi_bus_trim_one(adev, NULL); +} +EXPORT_SYMBOL_GPL(acpi_bus_trim); + static int acpi_scan_hot_remove(struct acpi_device *device) { acpi_handle handle = device->handle; @@ -2512,44 +2550,6 @@ int acpi_bus_scan(acpi_handle handle) } EXPORT_SYMBOL(acpi_bus_scan);
-static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) -{ - struct acpi_scan_handler *handler = adev->handler; - - acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL); - - adev->flags.match_driver = false; - if (handler) { - if (handler->detach) - handler->detach(adev); - - adev->handler = NULL; - } else { - device_release_driver(&adev->dev); - } - /* - * Most likely, the device is going away, so put it into D3cold before - * that. - */ - acpi_device_set_power(adev, ACPI_STATE_D3_COLD); - adev->flags.initialized = false; - acpi_device_clear_enumerated(adev); - - return 0; -} - -/** - * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects. - * @adev: Root of the ACPI namespace scope to walk. - * - * Must be called under acpi_scan_lock. - */ -void acpi_bus_trim(struct acpi_device *adev) -{ - acpi_bus_trim_one(adev, NULL); -} -EXPORT_SYMBOL_GPL(acpi_bus_trim); - int acpi_bus_register_early_device(int type) { struct acpi_device *device = NULL;
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 Tested-by: Miguel Luis miguel.luis@oracle.com Tested-by: Vishnu Pajjuri vishnu@os.amperecomputing.com Tested-by: Jianyong Wu jianyong.wu@arm.com Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 14 +++++--------- include/linux/acpi.h | 2 -- 2 files changed, 5 insertions(+), 11 deletions(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index c8e960ff0aca..26e3efb74614 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -183,13 +183,15 @@ static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */
/* Initialization */ -#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU -static int acpi_processor_hotadd_init(struct acpi_processor *pr) +static int acpi_processor_make_present(struct acpi_processor *pr) { unsigned long long sta; acpi_status status; int ret;
+ if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) + return -ENODEV; + if (invalid_phys_cpuid(pr->phys_id)) return -ENODEV;
@@ -223,12 +225,6 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) cpu_maps_update_done(); return ret; } -#else -static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) -{ - return -ENODEV; -} -#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
static int acpi_processor_get_info(struct acpi_device *device) { @@ -335,7 +331,7 @@ static int acpi_processor_get_info(struct acpi_device *device) * because cpuid <-> apicid mapping is persistent now. */ if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) { - int ret = acpi_processor_hotadd_init(pr); + int ret = acpi_processor_make_present(pr);
if (ret) return ret; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index ae879abbf51b..320da5e762ab 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -321,12 +321,10 @@ static inline int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu, } #endif
-#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU /* Arch dependent functions for cpu hotplug support */ int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id, int *pcpu); int acpi_unmap_cpu(int cpu); -#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 4 +-- drivers/acpi/scan.c | 52 ++++++++++++++++++++++++++++++----- include/acpi/acpi_bus.h | 1 + 3 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 26e3efb74614..b6f5005985c3 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -459,7 +459,7 @@ static int acpi_processor_add(struct acpi_device *device,
#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_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;
@@ -627,7 +627,7 @@ static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, #ifdef CONFIG_ACPI_HOTPLUG_PRESENT_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 e4db9d0c694c..7b2f126c335c 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -244,18 +244,28 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) return 0; }
-static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) +/** + * acpi_bus_trim_one() - Detach scan handlers and drivers from ACPI device + * objects. + * @adev: Root of the ACPI namespace scope to walk. + * @eject: Pointer to a bool that indicates if this was due to an + * eject-request. + * + * Must be called under acpi_scan_lock. + * If @eject points to true, clearing the device enumeration is deferred until + * acpi_bus_post_eject() is called. + */ +static int acpi_bus_trim_one(struct acpi_device *adev, void *eject) { struct acpi_scan_handler *handler = adev->handler; + bool is_eject = *(bool *)eject;
- acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, NULL); + acpi_dev_for_each_child_reverse(adev, acpi_bus_trim_one, eject);
adev->flags.match_driver = false; if (handler) { if (handler->detach) handler->detach(adev); - - adev->handler = NULL; } else { device_release_driver(&adev->dev); } @@ -265,7 +275,12 @@ static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) */ acpi_device_set_power(adev, ACPI_STATE_D3_COLD); adev->flags.initialized = false; - acpi_device_clear_enumerated(adev); + + /* For eject this is deferred to acpi_bus_post_eject() */ + if (!is_eject) { + adev->handler = NULL; + acpi_device_clear_enumerated(adev); + }
return 0; } @@ -278,15 +293,36 @@ static int acpi_bus_trim_one(struct acpi_device *adev, void *not_used) */ void acpi_bus_trim(struct acpi_device *adev) { - acpi_bus_trim_one(adev, NULL); + bool eject = false; + + acpi_bus_trim_one(adev, &eject); } EXPORT_SYMBOL_GPL(acpi_bus_trim);
+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; +} + static int acpi_scan_hot_remove(struct acpi_device *device) { acpi_handle handle = device->handle; unsigned long long sta; acpi_status status; + bool eject = true;
if (device->handler && device->handler->hotplug.demand_offline) { if (!acpi_scan_is_offline(device, true)) @@ -299,7 +335,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device)
acpi_handle_debug(handle, "Ejecting\n");
- acpi_bus_trim(device); + acpi_bus_trim_one(device, &eject);
acpi_evaluate_lck(handle, 0); /* @@ -322,6 +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 0b7eab0ef7d7..03f565245dfd 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -127,6 +127,7 @@ 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;
From: "Russell King (Oracle)" rmk+kernel@armlinux.org.uk
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
Rather than ifdef'ing acpi_processor_post_eject() and its use site, use IS_ENABLED() to increase compile coverage.
Signed-off-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b6f5005985c3..01c460881662 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -457,12 +457,14 @@ static int acpi_processor_add(struct acpi_device *device, return result; }
-#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU /* Removal */ static void acpi_processor_post_eject(struct acpi_device *device) { struct acpi_processor *pr;
+ if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) + return; + if (!device || !acpi_driver_data(device)) return;
@@ -501,7 +503,6 @@ static void acpi_processor_post_eject(struct acpi_device *device) free_cpumask_var(pr->throttling.shared_cpu_map); kfree(pr); } -#endif /* CONFIG_ACPI_HOTPLUG_PRESENT_CPU */
#ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC bool __init processor_physically_present(acpi_handle handle) @@ -626,9 +627,7 @@ static const struct acpi_device_id processor_device_ids[] = { static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, -#ifdef CONFIG_ACPI_HOTPLUG_PRESENT_CPU .post_eject = acpi_processor_post_eject, -#endif .hotplug = { .enabled = true, },
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 Tested-by: Miguel Luis miguel.luis@oracle.com Tested-by: Vishnu Pajjuri vishnu@os.amperecomputing.com Tested-by: Jianyong Wu jianyong.wu@arm.com Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 01c460881662..19fceb3ec4e2 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -458,16 +458,13 @@ static int acpi_processor_add(struct acpi_device *device, }
/* Removal */ -static void acpi_processor_post_eject(struct acpi_device *device) +static void acpi_processor_make_not_present(struct acpi_device *device) { struct acpi_processor *pr;
if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) return;
- if (!device || !acpi_driver_data(device)) - return; - pr = acpi_driver_data(device); if (pr->id >= nr_cpu_ids) goto out; @@ -504,6 +501,29 @@ static void acpi_processor_post_eject(struct acpi_device *device) kfree(pr); }
+static void acpi_processor_post_eject(struct acpi_device *device) +{ + struct acpi_processor *pr; + unsigned long long sta; + acpi_status status; + + if (!device) + return; + + pr = acpi_driver_data(device); + if (!pr || pr->id >= nr_cpu_ids || invalid_phys_cpuid(pr->phys_id)) + return; + + status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status)) + return; + + if (cpu_present(pr->id) && !(sta & ACPI_STA_DEVICE_PRESENT)) { + acpi_processor_make_not_present(device); + return; + } +} + #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC bool __init processor_physically_present(acpi_handle handle) {
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 19fceb3ec4e2..b7a94c1348b0 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -189,8 +189,10 @@ static int acpi_processor_make_present(struct acpi_processor *pr) acpi_status status; int ret;
- if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) + if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) { + pr_err_once("Changing CPU present bit is not supported\n"); return -ENODEV; + }
if (invalid_phys_cpuid(pr->phys_id)) return -ENODEV; @@ -462,8 +464,10 @@ static void acpi_processor_make_not_present(struct acpi_device *device) { struct acpi_processor *pr;
- if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) + if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) { + pr_err_once("Changing CPU present bit is not supported"); return; + }
pr = acpi_driver_data(device); if (pr->id >= nr_cpu_ids)
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- arch/arm64/include/asm/acpi.h | 11 +++++++++++ arch/arm64/kernel/acpi_numa.c | 11 ----------- 2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 6792a1f83f2a..bc9a6656fc0c 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -119,6 +119,17 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu) return acpi_cpu_get_madt_gicc(cpu)->uid; }
+static inline int get_cpu_for_acpi_id(u32 uid) +{ + int cpu; + + for (cpu = 0; cpu < nr_cpu_ids; cpu++) + if (uid == get_acpi_id_for_cpu(cpu)) + return cpu; + + return -EINVAL; +} + static inline void arch_fix_phys_package_id(int num, u32 slot) { } void __init acpi_init_cpus(void); int apei_claim_sea(struct pt_regs *regs); diff --git a/arch/arm64/kernel/acpi_numa.c b/arch/arm64/kernel/acpi_numa.c index e51535a5f939..0c036a9a3c33 100644 --- a/arch/arm64/kernel/acpi_numa.c +++ b/arch/arm64/kernel/acpi_numa.c @@ -34,17 +34,6 @@ int __init acpi_numa_get_nid(unsigned int cpu) return acpi_early_node_map[cpu]; }
-static inline int get_cpu_for_acpi_id(u32 uid) -{ - int cpu; - - for (cpu = 0; cpu < nr_cpu_ids; cpu++) - if (uid == get_acpi_id_for_cpu(cpu)) - return cpu; - - return -EINVAL; -} - static int __init acpi_parse_gicc_pxm(union acpi_subtable_headers *header, const unsigned long end) {
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- include/acpi/actbl2.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h index 3751ae69432f..c433a079d8e1 100644 --- a/include/acpi/actbl2.h +++ b/include/acpi/actbl2.h @@ -1046,6 +1046,7 @@ struct acpi_madt_generic_interrupt { /* ACPI_MADT_ENABLED (1) Processor is usable if set */ #define ACPI_MADT_PERFORMANCE_IRQ_MODE (1<<1) /* 01: Performance Interrupt Mode */ #define ACPI_MADT_VGIC_IRQ_MODE (1<<2) /* 02: VGIC Maintenance Interrupt mode */ +#define ACPI_MADT_GICC_CPU_CAPABLE (1<<3) /* 03: CPU is online capable */
/* 12: Generic Distributor (ACPI 5.0 + ACPI 6.0 changes) */
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- drivers/irqchip/irq-gic-v3.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 515cbb53dada..125198c69ae0 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -2441,21 +2441,15 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header,
/* * If GICC is enabled and has valid gicr base address, then it means - * GICR base is presented via GICC + * GICR base is presented via GICC. The redistributor is only known to + * be accessible if the GICC is marked as enabled. If this bit is not + * set, we'd need to add the redistributor at runtime, which isn't + * supported. */ - if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) { + if (gicc->flags & ACPI_MADT_ENABLED && gicc->gicr_base_address) acpi_data.enabled_rdists++; - return 0; - }
- /* - * It's perfectly valid firmware can pass disabled GICC entry, driver - * should not treat as errors, skip the entry instead of probe fail. - */ - if (!acpi_gicc_is_usable(gicc)) - return 0; - - return -ENODEV; + return 0; }
static int __init gic_acpi_count_gicr_regions(void)
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: 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) Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com
Signed-off-by: liwei liwei728@huawei.com --- drivers/irqchip/irq-gic-v3.c | 14 ++++++++++++++ include/linux/acpi.h | 2 +- 2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 125198c69ae0..d49d6e62f869 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -2391,11 +2391,25 @@ gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header, (struct acpi_madt_generic_interrupt *)header; u32 reg = readl_relaxed(acpi_data.dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK; u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2; + int cpu = get_cpu_for_acpi_id(gicc->uid); void __iomem *redist_base;
if (!acpi_gicc_is_usable(gicc)) return 0;
+ /* + * Capable but disabled CPUs can be brought online later. What about + * the redistributor? ACPI doesn't want to say! + * Virtual hotplug systems can use the MADT's "always-on" GICR entries. + * Otherwise, prevent such CPUs from being brought online. + */ + if (!(gicc->flags & ACPI_MADT_ENABLED)) { + pr_warn_once("CPU %u's redistributor is inaccessible: this CPU can't be brought online\n", cpu); + set_cpu_present(cpu, false); + set_cpu_possible(cpu, false); + return 0; + } + redist_base = ioremap(gicc->gicr_base_address, size); if (!redist_base) return -ENOMEM; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 320da5e762ab..d7a85792fef6 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -258,7 +258,7 @@ void acpi_table_print_madt_entry (struct acpi_subtable_header *madt);
static inline bool acpi_gicc_is_usable(struct acpi_madt_generic_interrupt *gicc) { - return gicc->flags & ACPI_MADT_ENABLED; + return gicc->flags & (ACPI_MADT_ENABLED | ACPI_MADT_GICC_CPU_CAPABLE); }
/* the following numa functions are architecture-dependent */
From: Jean-Philippe Brucker jean-philippe@linaro.org
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- arch/arm64/kernel/psci.c | 2 +- arch/arm64/kernel/smp.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 29a8e444db83..fabd732d0a2d 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -40,7 +40,7 @@ static int cpu_psci_cpu_boot(unsigned int cpu) { phys_addr_t pa_secondary_entry = __pa_symbol(secondary_entry); int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry); - if (err) + if (err && err != -EPERM) pr_err("failed to boot CPU%d (%d)\n", cpu, err);
return err; diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 0874834d33ec..32e47aabd486 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -125,7 +125,8 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) /* Now bring the CPU into our world */ ret = boot_secondary(cpu, idle); if (ret) { - pr_err("CPU%u: failed to boot: %d\n", cpu, ret); + if (ret != -EPERM) + pr_err("CPU%u: failed to boot: %d\n", cpu, ret); return ret; }
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Russell King (Oracle) rmk+kernel@armlinux.org.uk Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b7a94c1348b0..5dabb426481f 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -228,6 +228,32 @@ static int acpi_processor_make_present(struct acpi_processor *pr) return ret; }
+static int acpi_processor_make_enabled(struct acpi_processor *pr) +{ + unsigned long long sta; + acpi_status status; + bool present, enabled; + + if (!acpi_has_method(pr->handle, "_STA")) + return arch_register_cpu(pr->id); + + status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status)) + return -ENODEV; + + present = sta & ACPI_STA_DEVICE_PRESENT; + enabled = sta & ACPI_STA_DEVICE_ENABLED; + + if (cpu_online(pr->id) && (!present || !enabled)) { + pr_err_once(FW_BUG "CPU %u is online, but described as not present or disabled!\n", pr->id); + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); + } else if (!present || !enabled) { + return -ENODEV; + } + + return arch_register_cpu(pr->id); +} + static int acpi_processor_get_info(struct acpi_device *device) { union acpi_object object = { 0 }; @@ -318,7 +344,7 @@ static int acpi_processor_get_info(struct acpi_device *device) */ if (!invalid_logical_cpuid(pr->id) && cpu_present(pr->id) && !get_cpu_device(pr->id)) { - int ret = arch_register_cpu(pr->id); + int ret = acpi_processor_make_enabled(pr);
if (ret) return ret; @@ -526,6 +552,9 @@ static void acpi_processor_post_eject(struct acpi_device *device) acpi_processor_make_not_present(device); return; } + + if (cpu_present(pr->id) && !(sta & ACPI_STA_DEVICE_ENABLED)) + arch_unregister_cpu(pr->id); }
#ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 Tested-by: Miguel Luis miguel.luis@oracle.com Tested-by: Vishnu Pajjuri vishnu@os.amperecomputing.com Tested-by: Jianyong Wu jianyong.wu@arm.com Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- drivers/acpi/acpi_processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 5dabb426481f..ea12e70dfd39 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -537,7 +537,7 @@ static void acpi_processor_post_eject(struct acpi_device *device) unsigned long long sta; acpi_status status;
- if (!device) + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU) || !device) return;
pr = acpi_driver_data(device);
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 Reviewed-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: liwei liwei728@huawei.com --- Documentation/arch/arm64/cpu-hotplug.rst | 79 ++++++++++++++++++++++++ Documentation/arch/arm64/index.rst | 1 + 2 files changed, 80 insertions(+) create mode 100644 Documentation/arch/arm64/cpu-hotplug.rst
diff --git a/Documentation/arch/arm64/cpu-hotplug.rst b/Documentation/arch/arm64/cpu-hotplug.rst new file mode 100644 index 000000000000..76ba8d932c72 --- /dev/null +++ b/Documentation/arch/arm64/cpu-hotplug.rst @@ -0,0 +1,79 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. _cpuhp_index: + +==================== +CPU Hotplug and ACPI +==================== + +CPU hotplug in the arm64 world is commonly used to describe the kernel taking +CPUs online/offline using PSCI. This document is about ACPI firmware allowing +CPUs that were not available during boot to be added to the system later. + +``possible`` and ``present`` refer to the state of the CPU as seen by linux. + + +CPU Hotplug on physical systems - CPUs not present at boot +---------------------------------------------------------- + +Physical systems need to mark a CPU that is ``possible`` but not ``present`` as +being ``present``. An example would be a dual socket machine, where the package +in one of the sockets can be replaced while the system is running. + +This is not supported. + +In the arm64 world CPUs are not a single device but a slice of the system. +There are no systems that support the physical addition (or removal) of CPUs +while the system is running, and ACPI is not able to sufficiently describe +them. + +e.g. New CPUs come with new caches, but the platform's cache toplogy is +described in a static table, the PPTT. How caches are shared between CPUs is +not discoverable, and must be described by firmware. + +e.g. The GIC redistributor for each CPU must be accessed by the driver during +boot to discover the system wide supported features. ACPI's MADT GICC +structures can describe a redistributor associated with a disabled CPU, but +can't describe whether the redistributor is accessible, only that it is not +'always on'. + +arm64's ACPI tables assume that everything described is ``present``. + + +CPU Hotplug on virtual systems - CPUs not enabled at boot +--------------------------------------------------------- + +Virtual systems have the advantage that all the properties the system will +ever have can be described at boot. There are no power-domain considerations +as such devices are emulated. + +CPU Hotplug on virtual systems is supported. It is distinct from physical +CPU Hotplug as all resources are described as ``present``, but CPUs may be +marked as disabled by firmware. Only the CPU's online/offline behaviour is +influenced by firmware. An example is where a virtual machine boots with a +single CPU, and additional CPUs are added once a cloud orchestrator deploys +the workload. + +For a virtual machine, the VMM (e.g. Qemu) plays the part of firmware. + +Virtual hotplug is implemented as a firmware policy affecting which CPUs can be +brought online. Firmware can enforce its policy via PSCI's return codes. e.g. +``DENIED``. + +The ACPI tables must describe all the resources of the virtual machine. CPUs +that firmware wishes to disable either from boot (or later) should not be +``enabled`` in the MADT GICC structures, but should have the ``online capable`` +bit set, to indicate they can be enabled later. The boot CPU must be marked as +``enabled``. The 'always on' GICR structure must be used to describe the +redistributors. + +CPUs described as ``online capable`` but not ``enabled`` can be set to enabled +by the DSDT's Processor object's _STA method. On virtual systems the _STA method +must always report the CPU as ``present``. Changes to the firmware policy can +be notified to the OS via device-check or eject-request. + +CPUs described as ``enabled`` in the static table, should not have their _STA +modified dynamically by firmware. Soft-restart features such as kexec will +re-read the static properties of the system from these static tables, and +may malfunction if these no longer describe the running system. Linux will +re-discover the dynamic properties of the system from the _STA method later +during boot. diff --git a/Documentation/arch/arm64/index.rst b/Documentation/arch/arm64/index.rst index d08e924204bf..78544de0a8a9 100644 --- a/Documentation/arch/arm64/index.rst +++ b/Documentation/arch/arm64/index.rst @@ -13,6 +13,7 @@ ARM64 Architecture asymmetric-32bit booting cpu-feature-registers + cpu-hotplug elf_hwcaps hugetlbpage kdump
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: liwei liwei728@huawei.com --- arch/x86/Kconfig | 1 + drivers/acpi/Kconfig | 9 +++++++++ drivers/acpi/acpi_processor.c | 14 +++++++++++++- drivers/acpi/bus.c | 16 ++++++++++++++++ include/linux/acpi.h | 4 ++++ 5 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index caa325b45410..58b37e93407e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -61,6 +61,7 @@ config X86 select ACPI_LEGACY_TABLES_LOOKUP if ACPI select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI select ACPI_HOTPLUG_PRESENT_CPU if ACPI_PROCESSOR && HOTPLUG_CPU + select ACPI_HOTPLUG_IGNORE_OSC if ACPI && HOTPLUG_CPU select ARCH_32BIT_OFF_T if X86_32 select ARCH_CLOCKSOURCE_INIT select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 417f9f3077d2..c49978b4b11f 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -310,6 +310,15 @@ config ACPI_HOTPLUG_PRESENT_CPU depends on ACPI_PROCESSOR && HOTPLUG_CPU select ACPI_CONTAINER
+config ACPI_HOTPLUG_IGNORE_OSC + bool + depends on ACPI_HOTPLUG_PRESENT_CPU + help + Ignore whether firmware acknowledged support for toggling the CPU + present bit in _STA. Some architectures predate the _OSC bits, so + firmware doesn't know to do this. + + config ACPI_PROCESSOR_AGGREGATOR tristate "Processor Aggregator" depends on ACPI_PROCESSOR diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index ea12e70dfd39..5bb207a7a1dd 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -182,6 +182,18 @@ static void __init acpi_pcc_cpufreq_init(void) static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */
+static bool acpi_processor_hotplug_present_supported(void) +{ + if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) + return false; + + /* x86 systems pre-date the _OSC bit */ + if (IS_ENABLED(CONFIG_ACPI_HOTPLUG_IGNORE_OSC)) + return true; + + return osc_sb_hotplug_present_support_acked; +} + /* Initialization */ static int acpi_processor_make_present(struct acpi_processor *pr) { @@ -189,7 +201,7 @@ static int acpi_processor_make_present(struct acpi_processor *pr) acpi_status status; int ret;
- if (!IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) { + if (!acpi_processor_hotplug_present_supported()) { pr_err_once("Changing CPU present bit is not supported\n"); return -ENODEV; } diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index a4aa53b7e2bb..b42f17bfbb09 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -298,6 +298,13 @@ EXPORT_SYMBOL_GPL(osc_sb_native_usb4_support_confirmed);
bool osc_sb_cppc2_support_acked;
+/* + * ACPI 6.? Proposed Operating System Capabilities for modifying CPU + * present/enable. + */ +bool osc_sb_hotplug_enabled_support_acked; +bool osc_sb_hotplug_present_support_acked; + static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48"; static void acpi_bus_osc_negotiate_platform_control(void) { @@ -346,6 +353,11 @@ static void acpi_bus_osc_negotiate_platform_control(void)
if (!ghes_disable) capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT; + + capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_ENABLED_SUPPORT; + if (IS_ENABLED(CONFIG_ACPI_HOTPLUG_PRESENT_CPU)) + capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_PRESENT_SUPPORT; + if (ACPI_FAILURE(acpi_get_handle(NULL, "\_SB", &handle))) return;
@@ -383,6 +395,10 @@ static void acpi_bus_osc_negotiate_platform_control(void) capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT; osc_cpc_flexible_adr_space_confirmed = capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_CPC_FLEXIBLE_ADR_SPACE; + osc_sb_hotplug_enabled_support_acked = + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_HOTPLUG_ENABLED_SUPPORT; + osc_sb_hotplug_present_support_acked = + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_HOTPLUG_PRESENT_SUPPORT; }
kfree(context.ret.pointer); diff --git a/include/linux/acpi.h b/include/linux/acpi.h index d7a85792fef6..6a52349354be 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -579,12 +579,16 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context); #define OSC_SB_NATIVE_USB4_SUPPORT 0x00040000 #define OSC_SB_PRM_SUPPORT 0x00200000 #define OSC_SB_FFH_OPR_SUPPORT 0x00400000 +#define OSC_SB_HOTPLUG_ENABLED_SUPPORT 0x00800000 +#define OSC_SB_HOTPLUG_PRESENT_SUPPORT 0x01000000
extern bool osc_sb_apei_support_acked; extern bool osc_pc_lpi_support_confirmed; extern bool osc_sb_native_usb4_support_confirmed; extern bool osc_sb_cppc2_support_acked; extern bool osc_cpc_flexible_adr_space_confirmed; +extern bool osc_sb_hotplug_enabled_support_acked; +extern bool osc_sb_hotplug_present_support_acked;
/* USB4 Capabilities */ #define OSC_USB_USB3_TUNNELING 0x00000001
From: James Morse james.morse@arm.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8XMTL CVE: NA
---------------------------------
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 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: Thomas Gleixner tglx@linutronix.de Signed-off-by: liwei liwei728@huawei.com --- drivers/base/cpu.c | 10 ++++++++++ include/linux/cpumask.h | 25 +++++++++++++++++++++++++ kernel/cpu.c | 3 +++ 3 files changed, 38 insertions(+)
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 13d052bf13f4..a6e96a0a92b7 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -95,6 +95,7 @@ void unregister_cpu(struct cpu *cpu) { int logical_cpu = cpu->dev.id;
+ set_cpu_enabled(logical_cpu, false); unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu));
device_unregister(&cpu->dev); @@ -273,6 +274,13 @@ static ssize_t print_cpus_offline(struct device *dev, } static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL);
+static ssize_t print_cpus_enabled(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_enabled_mask)); +} +static DEVICE_ATTR(enabled, 0444, print_cpus_enabled, NULL); + static ssize_t print_cpus_isolated(struct device *dev, struct device_attribute *attr, char *buf) { @@ -413,6 +421,7 @@ int register_cpu(struct cpu *cpu, int num) register_cpu_under_node(num, cpu_to_node(num)); dev_pm_qos_expose_latency_limit(&cpu->dev, PM_QOS_RESUME_LATENCY_NO_CONSTRAINT); + set_cpu_enabled(num, true);
return 0; } @@ -494,6 +503,7 @@ static struct attribute *cpu_root_attrs[] = { &cpu_attrs[2].attr.attr, &dev_attr_kernel_max.attr, &dev_attr_offline.attr, + &dev_attr_enabled.attr, &dev_attr_isolated.attr, #ifdef CONFIG_NO_HZ_FULL &dev_attr_nohz_full.attr, diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index f10fb87d49db..a29ee03f13ff 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -92,6 +92,7 @@ static inline void set_nr_cpu_ids(unsigned int nr) * * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable * cpu_present_mask - has bit 'cpu' set iff cpu is populated + * cpu_enabled_mask - has bit 'cpu' set iff cpu can be brought online * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler * cpu_active_mask - has bit 'cpu' set iff cpu available to migration * @@ -124,11 +125,13 @@ static inline void set_nr_cpu_ids(unsigned int nr)
extern struct cpumask __cpu_possible_mask; extern struct cpumask __cpu_online_mask; +extern struct cpumask __cpu_enabled_mask; extern struct cpumask __cpu_present_mask; extern struct cpumask __cpu_active_mask; extern struct cpumask __cpu_dying_mask; #define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask) #define cpu_online_mask ((const struct cpumask *)&__cpu_online_mask) +#define cpu_enabled_mask ((const struct cpumask *)&__cpu_enabled_mask) #define cpu_present_mask ((const struct cpumask *)&__cpu_present_mask) #define cpu_active_mask ((const struct cpumask *)&__cpu_active_mask) #define cpu_dying_mask ((const struct cpumask *)&__cpu_dying_mask) @@ -973,6 +976,7 @@ extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); #else #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) +#define for_each_enabled_cpu(cpu) for_each_cpu((cpu), cpu_enabled_mask) #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) #endif
@@ -995,6 +999,15 @@ set_cpu_possible(unsigned int cpu, bool possible) cpumask_clear_cpu(cpu, &__cpu_possible_mask); }
+static inline void +set_cpu_enabled(unsigned int cpu, bool can_be_onlined) +{ + if (can_be_onlined) + cpumask_set_cpu(cpu, &__cpu_enabled_mask); + else + cpumask_clear_cpu(cpu, &__cpu_enabled_mask); +} + static inline void set_cpu_present(unsigned int cpu, bool present) { @@ -1074,6 +1087,7 @@ static __always_inline unsigned int num_online_cpus(void) return raw_atomic_read(&__num_online_cpus); } #define num_possible_cpus() cpumask_weight(cpu_possible_mask) +#define num_enabled_cpus() cpumask_weight(cpu_enabled_mask) #define num_present_cpus() cpumask_weight(cpu_present_mask) #define num_active_cpus() cpumask_weight(cpu_active_mask)
@@ -1082,6 +1096,11 @@ static inline bool cpu_online(unsigned int cpu) return cpumask_test_cpu(cpu, cpu_online_mask); }
+static inline bool cpu_enabled(unsigned int cpu) +{ + return cpumask_test_cpu(cpu, cpu_enabled_mask); +} + static inline bool cpu_possible(unsigned int cpu) { return cpumask_test_cpu(cpu, cpu_possible_mask); @@ -1106,6 +1125,7 @@ static inline bool cpu_dying(unsigned int cpu)
#define num_online_cpus() 1U #define num_possible_cpus() 1U +#define num_enabled_cpus() 1U #define num_present_cpus() 1U #define num_active_cpus() 1U
@@ -1119,6 +1139,11 @@ static inline bool cpu_possible(unsigned int cpu) return cpu == 0; }
+static inline bool cpu_enabled(unsigned int cpu) +{ + return cpu == 0; +} + static inline bool cpu_present(unsigned int cpu) { return cpu == 0; diff --git a/kernel/cpu.c b/kernel/cpu.c index 72e0f5380bf6..75c4e69c06cf 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -3118,6 +3118,9 @@ EXPORT_SYMBOL(__cpu_possible_mask); struct cpumask __cpu_online_mask __read_mostly; EXPORT_SYMBOL(__cpu_online_mask);
+struct cpumask __cpu_enabled_mask __read_mostly; +EXPORT_SYMBOL(__cpu_enabled_mask); + struct cpumask __cpu_present_mask __read_mostly; EXPORT_SYMBOL(__cpu_present_mask);
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