From c1385c1f0ba3b80bd12f26c440612175088c664c Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:28 +0100 Subject: [PATCH 01/21] ACPI: processor: Simplify initial onlining to use same path for cold and hotplug Separate code paths, combined with a flag set in acpi_processor.c to indicate a struct acpi_processor was for a hotplugged CPU ensured that per CPU data was only set up the first time that a CPU was initialized. This appears to be unnecessary as the paths can be combined by letting the online logic also handle any CPUs online at the time of driver load. Motivation for this change, beyond simplification, is that ARM64 virtual CPU HP uses the same code paths for hotplug and cold path in acpi_processor.c so had no easy way to set the flag for hotplug only. Removing this necessity will enable ARM64 vCPU HP to reuse the existing code paths. Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Tested-by: Miguel Luis Reviewed-by: Gavin Shan Reviewed-by: Miguel Luis Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-2-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 7 +++--- drivers/acpi/processor_driver.c | 43 +++++++++------------------------ include/acpi/processor.h | 2 +- 3 files changed, 16 insertions(+), 36 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 7a0dd35d62c9..b2f0b6c19482 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -211,12 +211,11 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) } /* - * CPU got hot-added, but cpu_data is not initialized yet. Set a flag - * to delay cpu_idle/throttling initialization and do it when the CPU - * gets online for the first time. + * CPU got hot-added, but cpu_data is not initialized yet. Do + * cpu_idle/throttling initialization when the CPU gets online for + * the first time. */ pr_info("CPU%d has been hot-added\n", pr->id); - pr->flags.need_hotplug_init = 1; out: cpus_write_unlock(); diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 67db60eda370..cb52dd000b95 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -33,7 +33,6 @@ MODULE_AUTHOR("Paul Diefenbaugh"); MODULE_DESCRIPTION("ACPI Processor Driver"); MODULE_LICENSE("GPL"); -static int acpi_processor_start(struct device *dev); static int acpi_processor_stop(struct device *dev); static const struct acpi_device_id processor_device_ids[] = { @@ -47,7 +46,6 @@ static struct device_driver acpi_processor_driver = { .name = "processor", .bus = &cpu_subsys, .acpi_match_table = processor_device_ids, - .probe = acpi_processor_start, .remove = acpi_processor_stop, }; @@ -115,12 +113,9 @@ static int acpi_soft_cpu_online(unsigned int cpu) * CPU got physically hotplugged and onlined for the first time: * Initialize missing things. */ - if (pr->flags.need_hotplug_init) { + if (!pr->flags.previously_online) { int ret; - pr_info("Will online and init hotplugged CPU: %d\n", - pr->id); - pr->flags.need_hotplug_init = 0; ret = __acpi_processor_start(device); WARN(ret, "Failed to start CPU: %d\n", pr->id); } else { @@ -167,9 +162,6 @@ static int __acpi_processor_start(struct acpi_device *device) if (!pr) return -ENODEV; - if (pr->flags.need_hotplug_init) - return 0; - result = acpi_cppc_processor_probe(pr); if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS)) dev_dbg(&device->dev, "CPPC data invalid or not present\n"); @@ -185,32 +177,21 @@ static int __acpi_processor_start(struct acpi_device *device) status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, acpi_processor_notify, device); - if (ACPI_SUCCESS(status)) - return 0; + if (!ACPI_SUCCESS(status)) { + result = -ENODEV; + goto err_thermal_exit; + } + pr->flags.previously_online = 1; - result = -ENODEV; + return 0; + +err_thermal_exit: acpi_processor_thermal_exit(pr, device); - err_power_exit: acpi_processor_power_exit(pr); return result; } -static int acpi_processor_start(struct device *dev) -{ - struct acpi_device *device = ACPI_COMPANION(dev); - int ret; - - if (!device) - return -ENODEV; - - /* Protect against concurrent CPU hotplug operations */ - cpu_hotplug_disable(); - ret = __acpi_processor_start(device); - cpu_hotplug_enable(); - return ret; -} - static int acpi_processor_stop(struct device *dev) { struct acpi_device *device = ACPI_COMPANION(dev); @@ -279,9 +260,9 @@ static int __init acpi_processor_driver_init(void) if (result < 0) return result; - result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, - "acpi/cpu-drv:online", - acpi_soft_cpu_online, NULL); + result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, + "acpi/cpu-drv:online", + acpi_soft_cpu_online, NULL); if (result < 0) goto err; hp_online = result; diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 3f34ebb27525..e6f6074eadbf 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -217,7 +217,7 @@ struct acpi_processor_flags { u8 has_lpi:1; u8 power_setup_done:1; u8 bm_rld_set:1; - u8 need_hotplug_init:1; + u8 previously_online:1; }; struct acpi_processor { From d830ef3ac56941089f49ec13c80ea4aaa3c2e6c0 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:29 +0100 Subject: [PATCH 02/21] cpu: Do not warn on arch_register_cpu() returning -EPROBE_DEFER For arm64 the CPU registration cannot complete until the ACPI interpreter us up and running so in those cases the arch specific arch_register_cpu() will return -EPROBE_DEFER at this stage and the registration will be attempted later. Suggested-by: Rafael J. Wysocki Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Reviewed-by: Gavin Shan Tested-by: Miguel Luis Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-3-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/base/cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index c61ecb0c2ae2..1487cd9761a4 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -558,7 +558,7 @@ static void __init cpu_dev_register_generic(void) for_each_present_cpu(i) { ret = arch_register_cpu(i); - if (ret) + if (ret && ret != -EPROBE_DEFER) pr_warn("register_cpu %d failed (%d)\n", i, ret); } } From 157080f03c7abb7df58c4cb519e18c188cfb7404 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:30 +0100 Subject: [PATCH 03/21] ACPI: processor: Drop duplicated check on _STA (enabled + present) The ACPI bus scan will only result in acpi_processor_add() being called if _STA has already been checked and the result is that the processor is enabled and present. Hence drop this additional check. Suggested-by: Rafael J. Wysocki Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Reviewed-by: Gavin Shan Tested-by: Miguel Luis Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-4-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index b2f0b6c19482..161c95c9d60a 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -186,17 +186,11 @@ static void __init acpi_pcc_cpufreq_init(void) {} #ifdef CONFIG_ACPI_HOTPLUG_CPU static int acpi_processor_hotadd_init(struct acpi_processor *pr) { - unsigned long long sta; - acpi_status status; int ret; if (invalid_phys_cpuid(pr->phys_id)) return -ENODEV; - status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta); - if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) - return -ENODEV; - cpu_maps_update_begin(); cpus_write_lock(); From fadf231f0a06a6748a7fc4a2c29ac9ef7bca6bfd Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:31 +0100 Subject: [PATCH 04/21] ACPI: processor: Return an error if acpi_processor_get_info() fails in processor_add() Rafael observed [1] that returning 0 from processor_add() will result in acpi_default_enumeration() being called which will attempt to create a platform device, but that makes little sense when the processor is known to be not available. So just return the error code from acpi_processor_get_info() instead. Link: https://lore.kernel.org/all/CAJZ5v0iKU8ra9jR+EmgxbuNm=Uwx2m1-8vn_RAZ+aCiUVLe3Pw@mail.gmail.com/ [1] Suggested-by: Rafael J. Wysocki Acked-by: Rafael J. Wysocki Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-5-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- 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 161c95c9d60a..5f062806ca40 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -393,7 +393,7 @@ static int acpi_processor_add(struct acpi_device *device, result = acpi_processor_get_info(device); if (result) /* Processor is not physically present or unavailable */ - return 0; + return result; BUG_ON(pr->id >= nr_cpu_ids); From 47ec9b417ed9b6b8ec2a941cd84d9de62adc358a Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:32 +0100 Subject: [PATCH 05/21] ACPI: processor: Fix memory leaks in error paths of processor_add() If acpi_processor_get_info() returned an error, pr and the associated pr->throttling.shared_cpu_map were leaked. The unwind code was in the wrong order wrt to setup, relying on some unwind actions having no affect (clearing variables that were never set etc). That makes it harder to reason about so reorder and add appropriate labels to only undo what was actually set up in the first place. Acked-by: Rafael J. Wysocki Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-6-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 5f062806ca40..16e36e55a560 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -393,7 +393,7 @@ static int acpi_processor_add(struct acpi_device *device, result = acpi_processor_get_info(device); if (result) /* Processor is not physically present or unavailable */ - return result; + goto err_clear_driver_data; BUG_ON(pr->id >= nr_cpu_ids); @@ -408,7 +408,7 @@ static int acpi_processor_add(struct acpi_device *device, "BIOS reported wrong ACPI id %d for the processor\n", pr->id); /* Give up, but do not abort the namespace scan. */ - goto err; + goto err_clear_driver_data; } /* * processor_device_array is not cleared on errors to allow buggy BIOS @@ -420,12 +420,12 @@ static int acpi_processor_add(struct acpi_device *device, dev = get_cpu_device(pr->id); if (!dev) { result = -ENODEV; - goto err; + goto err_clear_per_cpu; } result = acpi_bind_one(dev, device); if (result) - goto err; + goto err_clear_per_cpu; pr->dev = dev; @@ -436,10 +436,11 @@ static int acpi_processor_add(struct acpi_device *device, dev_err(dev, "Processor driver could not be attached\n"); acpi_unbind_one(dev); - err: - free_cpumask_var(pr->throttling.shared_cpu_map); - device->driver_data = NULL; + err_clear_per_cpu: per_cpu(processors, pr->id) = NULL; + err_clear_driver_data: + device->driver_data = NULL; + free_cpumask_var(pr->throttling.shared_cpu_map); err_free_pr: kfree(pr); return result; From cd9239660b8c0357a7338a33d40a429e48273e77 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:33 +0100 Subject: [PATCH 06/21] ACPI: processor: Move checks and availability of acpi_processor earlier Make the per_cpu(processors, cpu) entries available earlier so that they are available in arch_register_cpu() as ARM64 will need access to the acpi_handle to distinguish between acpi_processor_add() and earlier registration attempts (which will fail as _STA cannot be checked). Reorder the remove flow to clear this per_cpu() after arch_unregister_cpu() has completed, allowing it to be used in there as well. Note that on x86 for the CPU hotplug case, the pr->id prior to acpi_map_cpu() may be invalid. Thus the per_cpu() structures must be initialized after that call or after checking the ID is valid (not hotplug path). Acked-by: Rafael J. Wysocki Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-7-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 88 +++++++++++++++++++++-------------- 1 file changed, 52 insertions(+), 36 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 16e36e55a560..0bc0419adf6b 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -183,8 +183,38 @@ static void __init acpi_pcc_cpufreq_init(void) {} #endif /* CONFIG_X86 */ /* Initialization */ +static DEFINE_PER_CPU(void *, processor_device_array); + +static int acpi_processor_set_per_cpu(struct acpi_processor *pr, + struct acpi_device *device) +{ + BUG_ON(pr->id >= nr_cpu_ids); + + /* + * Buggy BIOS check. + * ACPI id of processors can be reported wrongly by the BIOS. + * Don't trust it blindly + */ + if (per_cpu(processor_device_array, pr->id) != NULL && + per_cpu(processor_device_array, pr->id) != device) { + dev_warn(&device->dev, + "BIOS reported wrong ACPI id %d for the processor\n", + pr->id); + return -EINVAL; + } + /* + * processor_device_array is not cleared on errors to allow buggy BIOS + * checks. + */ + per_cpu(processor_device_array, pr->id) = device; + per_cpu(processors, pr->id) = pr; + + return 0; +} + #ifdef CONFIG_ACPI_HOTPLUG_CPU -static int acpi_processor_hotadd_init(struct acpi_processor *pr) +static int acpi_processor_hotadd_init(struct acpi_processor *pr, + struct acpi_device *device) { int ret; @@ -198,8 +228,16 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr) if (ret) goto out; + ret = acpi_processor_set_per_cpu(pr, device); + if (ret) { + acpi_unmap_cpu(pr->id); + goto out; + } + ret = arch_register_cpu(pr->id); if (ret) { + /* Leave the processor device array in place to detect buggy bios */ + per_cpu(processors, pr->id) = NULL; acpi_unmap_cpu(pr->id); goto out; } @@ -217,7 +255,8 @@ out: return ret; } #else -static inline int acpi_processor_hotadd_init(struct acpi_processor *pr) +static inline int acpi_processor_hotadd_init(struct acpi_processor *pr, + struct acpi_device *device) { return -ENODEV; } @@ -232,6 +271,7 @@ static int acpi_processor_get_info(struct acpi_device *device) acpi_status status = AE_OK; static int cpu0_initialized; unsigned long long value; + int ret; acpi_processor_errata(); @@ -315,12 +355,12 @@ static int acpi_processor_get_info(struct acpi_device *device) * NOTE: Even if the processor has a cpuid, it may not be present * because cpuid <-> apicid mapping is persistent now. */ - if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) { - int ret = acpi_processor_hotadd_init(pr); - - if (ret) - return ret; - } + if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) + ret = acpi_processor_hotadd_init(pr, device); + else + ret = acpi_processor_set_per_cpu(pr, device); + if (ret) + return ret; /* * On some boxes several processors use the same processor bus id. @@ -365,8 +405,6 @@ static int acpi_processor_get_info(struct acpi_device *device) * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. * Such things have to be put in and set up by the processor driver's .probe(). */ -static DEFINE_PER_CPU(void *, processor_device_array); - static int acpi_processor_add(struct acpi_device *device, const struct acpi_device_id *id) { @@ -395,28 +433,6 @@ static int acpi_processor_add(struct acpi_device *device, if (result) /* Processor is not physically present or unavailable */ goto err_clear_driver_data; - BUG_ON(pr->id >= nr_cpu_ids); - - /* - * Buggy BIOS check. - * ACPI id of processors can be reported wrongly by the BIOS. - * Don't trust it blindly - */ - if (per_cpu(processor_device_array, pr->id) != NULL && - per_cpu(processor_device_array, pr->id) != device) { - dev_warn(&device->dev, - "BIOS reported wrong ACPI id %d for the processor\n", - pr->id); - /* Give up, but do not abort the namespace scan. */ - goto err_clear_driver_data; - } - /* - * processor_device_array is not cleared on errors to allow buggy BIOS - * checks. - */ - per_cpu(processor_device_array, pr->id) = device; - per_cpu(processors, pr->id) = pr; - dev = get_cpu_device(pr->id); if (!dev) { result = -ENODEV; @@ -470,10 +486,6 @@ static void acpi_processor_remove(struct acpi_device *device) device_release_driver(pr->dev); acpi_unbind_one(pr->dev); - /* Clean up. */ - per_cpu(processor_device_array, pr->id) = NULL; - per_cpu(processors, pr->id) = NULL; - cpu_maps_update_begin(); cpus_write_lock(); @@ -481,6 +493,10 @@ static void acpi_processor_remove(struct acpi_device *device) arch_unregister_cpu(pr->id); acpi_unmap_cpu(pr->id); + /* Clean up. */ + per_cpu(processor_device_array, pr->id) = NULL; + per_cpu(processors, pr->id) = NULL; + cpus_write_unlock(); cpu_maps_update_done(); From 36b921637e900c77f5f9bd5b45db522124068a96 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:34 +0100 Subject: [PATCH 07/21] ACPI: processor: Add acpi_get_processor_handle() helper If CONFIG_ACPI_PROCESSOR provide a helper to retrieve the acpi_handle for a given CPU allowing access to methods in DSDT. Tested-by: Miguel Luis Reviewed-by: Gavin Shan Acked-by: Rafael J. Wysocki Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-8-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 11 +++++++++++ include/linux/acpi.h | 7 +++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 0bc0419adf6b..56592462d2fb 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -35,6 +35,17 @@ EXPORT_PER_CPU_SYMBOL(processors); struct acpi_processor_errata errata __read_mostly; EXPORT_SYMBOL_GPL(errata); +acpi_handle acpi_get_processor_handle(int cpu) +{ + struct acpi_processor *pr; + + pr = per_cpu(processors, cpu); + if (pr) + return pr->handle; + + return NULL; +} + static int acpi_processor_errata_piix4(struct pci_dev *dev) { u8 value1 = 0; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 28c3fb2bef0d..fd45bfab66b8 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -304,6 +304,8 @@ int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id, int acpi_unmap_cpu(int cpu); #endif /* CONFIG_ACPI_HOTPLUG_CPU */ +acpi_handle acpi_get_processor_handle(int cpu); + #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr); #endif @@ -1076,6 +1078,11 @@ static inline bool acpi_sleep_state_supported(u8 sleep_state) return false; } +static inline acpi_handle acpi_get_processor_handle(int cpu) +{ + return NULL; +} + #endif /* !CONFIG_ACPI */ extern void arch_post_acpi_subsys_init(void); From b398a91decd9d4b399389a12675ea7716039b964 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:35 +0100 Subject: [PATCH 08/21] ACPI: processor: Register deferred CPUs from acpi_processor_get_info() The arm64 specific arch_register_cpu() call may defer CPU registration until the ACPI interpreter is available and the _STA method can be evaluated. If this occurs, then a second attempt is made in acpi_processor_get_info(). Note that the arm64 specific call has not yet been added so for now this will be called for the original hotplug case. For architectures that do not defer until the ACPI Processor driver loads (e.g. x86), for initially present CPUs there will already be a CPU device. If present do not try to register again. Systems can still be booted with 'acpi=off', or not include an ACPI description at all as in these cases arch_register_cpu() will not have deferred registration when first called. This moves the CPU register logic back to a subsys_initcall(), while the memory nodes will have been registered earlier. Note this is where the call was prior to the cleanup series so there should be no side effects of moving it back again for this specific case. [PATCH 00/21] Initial cleanups for vCPU HP. https://lore.kernel.org/all/ZVyz%2FVe5pPu8AWoA@shell.armlinux.org.uk/ commit 5b95f94c3b9f ("x86/topology: Switch over to GENERIC_CPU_DEVICES") Signed-off-by: James Morse Signed-off-by: Russell King (Oracle) Reviewed-by: Gavin Shan Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Reviewed-by: Hanjun Guo Acked-by: Rafael J. Wysocki Co-developed-by: Jonathan Cameron Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-9-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 56592462d2fb..f0b7a789f0a1 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -359,14 +359,14 @@ static int acpi_processor_get_info(struct acpi_device *device) } /* - * Extra Processor objects may be enumerated on MP systems with - * less than the max # of CPUs. They should be ignored _iff - * they are physically not present. - * - * NOTE: Even if the processor has a cpuid, it may not be present - * because cpuid <-> apicid mapping is persistent now. + * This code is not called unless we know the CPU is present and + * enabled. The two paths are: + * a) Initially present CPUs on architectures that do not defer + * their arch_register_cpu() calls until this point. + * b) Hotplugged CPUs (enabled bit in _STA has transitioned from not + * enabled to enabled) */ - if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) + if (!get_cpu_device(pr->id)) ret = acpi_processor_hotadd_init(pr, device); else ret = acpi_processor_set_per_cpu(pr, device); From 1859a671bdb9b3df114c3fdf85b1032a9a8d208d Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:36 +0100 Subject: [PATCH 09/21] ACPI: scan: switch to flags for acpi_scan_check_and_detach() Precursor patch adds the ability to pass a uintptr_t of flags into acpi_scan_check_and detach() so that additional flags can be added to indicate whether to defer portions of the eject flow. The new flag follows in the next patch. Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Reviewed-by: Gavin Shan Tested-by: Miguel Luis Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-10-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/scan.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 503773707e01..4d649ce5876f 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -243,13 +243,16 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) return 0; } -static int acpi_scan_check_and_detach(struct acpi_device *adev, void *check) +#define ACPI_SCAN_CHECK_FLAG_STATUS BIT(0) + +static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p) { struct acpi_scan_handler *handler = adev->handler; + uintptr_t flags = (uintptr_t)p; - acpi_dev_for_each_child_reverse(adev, acpi_scan_check_and_detach, check); + acpi_dev_for_each_child_reverse(adev, acpi_scan_check_and_detach, p); - if (check) { + if (flags & ACPI_SCAN_CHECK_FLAG_STATUS) { acpi_bus_get_status(adev); /* * Skip devices that are still there and take the enabled @@ -287,7 +290,9 @@ static int acpi_scan_check_and_detach(struct acpi_device *adev, void *check) static void acpi_scan_check_subtree(struct acpi_device *adev) { - acpi_scan_check_and_detach(adev, (void *)true); + uintptr_t flags = ACPI_SCAN_CHECK_FLAG_STATUS; + + acpi_scan_check_and_detach(adev, (void *)flags); } static int acpi_scan_hot_remove(struct acpi_device *device) @@ -2596,7 +2601,9 @@ EXPORT_SYMBOL(acpi_bus_scan); */ void acpi_bus_trim(struct acpi_device *adev) { - acpi_scan_check_and_detach(adev, NULL); + uintptr_t flags = 0; + + acpi_scan_check_and_detach(adev, (void *)flags); } EXPORT_SYMBOL_GPL(acpi_bus_trim); From 3b9d0a78aeda194994892f7c42f6ca5feb45eadd Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:37 +0100 Subject: [PATCH 10/21] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug struct acpi_scan_handler has a detach callback that is used to remove a driver when a bus is changed. When interacting with an eject-request, the detach callback is called before _EJ0. This means the ACPI processor driver can't use _STA to determine if a CPU has been made not-present, or some of the other _STA bits have been changed. acpi_processor_remove() needs to know the value of _STA after _EJ0 has been called. Add a post_eject callback to struct acpi_scan_handler. This is called after acpi_scan_hot_remove() has successfully called _EJ0. Because acpi_scan_check_and_detach() also clears the handler pointer, it needs to be told if the caller will go on to call acpi_bus_post_eject(), so that acpi_device_clear_enumerated() and clearing the handler pointer can be deferred. An extra flag is added to flags field introduced in the previous patch to achieve this. Signed-off-by: James Morse Reviewed-by: Gavin Shan Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Acked-by: Rafael J. Wysocki Reviewed-by: Hanjun Guo Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-11-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/acpi/acpi_processor.c | 4 ++-- drivers/acpi/scan.c | 30 +++++++++++++++++++++++++++--- include/acpi/acpi_bus.h | 1 + 3 files changed, 30 insertions(+), 5 deletions(-) diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index f0b7a789f0a1..64e10bad8072 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -475,7 +475,7 @@ static int acpi_processor_add(struct acpi_device *device, #ifdef CONFIG_ACPI_HOTPLUG_CPU /* Removal */ -static void acpi_processor_remove(struct acpi_device *device) +static void acpi_processor_post_eject(struct acpi_device *device) { struct acpi_processor *pr; @@ -643,7 +643,7 @@ static struct acpi_scan_handler processor_handler = { .ids = processor_device_ids, .attach = acpi_processor_add, #ifdef CONFIG_ACPI_HOTPLUG_CPU - .detach = acpi_processor_remove, + .post_eject = acpi_processor_post_eject, #endif .hotplug = { .enabled = true, diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 4d649ce5876f..0aa20623525a 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -244,6 +244,7 @@ static int acpi_scan_try_to_offline(struct acpi_device *device) } #define ACPI_SCAN_CHECK_FLAG_STATUS BIT(0) +#define ACPI_SCAN_CHECK_FLAG_EJECT BIT(1) static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p) { @@ -272,8 +273,6 @@ static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p) if (handler) { if (handler->detach) handler->detach(adev); - - adev->handler = NULL; } else { device_release_driver(&adev->dev); } @@ -283,6 +282,28 @@ static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p) */ acpi_device_set_power(adev, ACPI_STATE_D3_COLD); adev->flags.initialized = false; + + /* For eject this is deferred to acpi_bus_post_eject() */ + if (!(flags & ACPI_SCAN_CHECK_FLAG_EJECT)) { + adev->handler = NULL; + acpi_device_clear_enumerated(adev); + } + return 0; +} + +static int acpi_bus_post_eject(struct acpi_device *adev, void *not_used) +{ + struct acpi_scan_handler *handler = adev->handler; + + acpi_dev_for_each_child_reverse(adev, acpi_bus_post_eject, NULL); + + if (handler) { + if (handler->post_eject) + handler->post_eject(adev); + + adev->handler = NULL; + } + acpi_device_clear_enumerated(adev); return 0; @@ -300,6 +321,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device) acpi_handle handle = device->handle; unsigned long long sta; acpi_status status; + uintptr_t flags = ACPI_SCAN_CHECK_FLAG_EJECT; if (device->handler && device->handler->hotplug.demand_offline) { if (!acpi_scan_is_offline(device, true)) @@ -312,7 +334,7 @@ static int acpi_scan_hot_remove(struct acpi_device *device) acpi_handle_debug(handle, "Ejecting\n"); - acpi_bus_trim(device); + acpi_scan_check_and_detach(device, (void *)flags); acpi_evaluate_lck(handle, 0); /* @@ -335,6 +357,8 @@ static int acpi_scan_hot_remove(struct acpi_device *device) } else if (sta & ACPI_STA_DEVICE_ENABLED) { acpi_handle_warn(handle, "Eject incomplete - status 0x%llx\n", sta); + } else { + acpi_bus_post_eject(device, NULL); } return 0; diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 1a4dfd7a1c4a..05ca49478537 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -134,6 +134,7 @@ struct acpi_scan_handler { bool (*match)(const char *idstr, const struct acpi_device_id **matchid); int (*attach)(struct acpi_device *dev, const struct acpi_device_id *id); void (*detach)(struct acpi_device *dev); + void (*post_eject)(struct acpi_device *dev); void (*bind)(struct device *phys_dev); void (*unbind)(struct device *phys_dev); struct acpi_hotplug_profile hotplug; From 8d34b6f17b9ac93faa2791eb037dcb08bdf755de Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:38 +0100 Subject: [PATCH 11/21] arm64: acpi: Move get_cpu_for_acpi_id() to a header 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 Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Signed-off-by: Russell King (Oracle) Acked-by: Hanjun Guo Signed-off-by: Jonathan Cameron Reviewed-by: Lorenzo Pieralisi Link: https://lore.kernel.org/r/20240529133446.28446-12-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- 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 2488444274c70038eb6b686cba5f1ce48ebb9cdd Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:39 +0100 Subject: [PATCH 12/21] arm64: acpi: Harden get_cpu_for_acpi_id() against missing CPU entry In a review discussion of the changes to support vCPU hotplug where a check was added on the GICC being enabled if was online, it was noted that there is need to map back to the cpu and use that to index into a cpumask. As such, a valid ID is needed. If an MPIDR check fails in acpi_map_gic_cpu_interface() it is possible for the entry in cpu_madt_gicc[cpu] == NULL. This function would then cause a NULL pointer dereference. Whilst a path to trigger this has not been established, harden this caller against the possibility. Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-13-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/acpi.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index bc9a6656fc0c..a407f9cd549e 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -124,7 +124,8 @@ 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)) + if (acpi_cpu_get_madt_gicc(cpu) && + uid == get_acpi_id_for_cpu(cpu)) return cpu; return -EINVAL; From fa2dabe57220e6af78ed7a2f7016bf250a618204 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:40 +0100 Subject: [PATCH 13/21] irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() 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 will complicate 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 Reviewed-by: Gavin Shan Tested-by: Miguel Luis Signed-off-by: Russell King (Oracle) Reviewed-by: Jonathan Cameron Signed-off-by: Jonathan Cameron Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20240529133446.28446-14-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- drivers/irqchip/irq-gic-v3.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 6fb276504bcc..10af15f93d4d 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -2415,19 +2415,10 @@ 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 */ - if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) { + if (acpi_gicc_is_usable(gicc) && 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 d633da5d3ab1a0eb26a2213d65da1e189e82f8ab Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:41 +0100 Subject: [PATCH 14/21] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs 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. This means that a "usable" GIC redistributor is one that is marked as either enabled, or online capable. The meaning of the acpi_gicc_is_usable() would become less clear than just checking the pair of flags at call sites. As such, drop that helper function. The test in gic_acpi_match_gicc() remains as testing just the enabled bit so the count of enabled distributors is correct. 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. Rather than modifying cpu masks that may already have been used, register a new cpuhp callback to fail this case. This must run earlier than the main gic_starting_cpu() so that this case can be rejected before the section of cpuhp that runs on the CPU that is coming up as that is not allowed to fail. This solution keeps the handling of this broken firmware corner case local to the GIC driver. As precise ordering of this callback doesn't need to be controlled as long as it is in that initial prepare phase, use CPUHP_BP_PREPARE_DYN. 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. Suggested-by: Marc Zyngier Signed-off-by: James Morse Signed-off-by: Russell King (Oracle) Tested-by: Miguel Luis Co-developed-by: Jonathan Cameron Signed-off-by: Jonathan Cameron Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20240529133446.28446-15-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/kernel/smp.c | 3 ++- drivers/acpi/processor_core.c | 3 ++- drivers/irqchip/irq-gic-v3.c | 46 ++++++++++++++++++++++++++++++++--- include/linux/acpi.h | 5 ---- 4 files changed, 46 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 31c8b3094dd7..6b0572daa9da 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -530,7 +530,8 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor) { u64 hwid = processor->arm_mpidr; - if (!acpi_gicc_is_usable(processor)) { + if (!(processor->flags & + (ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE))) { pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid); return; } diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c index b203cfe28550..b04b684f3190 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -90,7 +90,8 @@ static int map_gicc_mpidr(struct acpi_subtable_header *entry, struct acpi_madt_generic_interrupt *gicc = container_of(entry, struct acpi_madt_generic_interrupt, header); - if (!acpi_gicc_is_usable(gicc)) + if (!(gicc->flags & + (ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE))) return -ENODEV; /* device_declaration means Device object in DSDT, in the diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 10af15f93d4d..cc81515c1413 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -44,6 +44,8 @@ #define GIC_IRQ_TYPE_PARTITION (GIC_IRQ_TYPE_LPI + 1) +static struct cpumask broken_rdists __read_mostly; + struct redist_region { void __iomem *redist_base; phys_addr_t phys_base; @@ -1293,6 +1295,18 @@ static void gic_cpu_init(void) #define MPIDR_TO_SGI_RS(mpidr) (MPIDR_RS(mpidr) << ICC_SGI1R_RS_SHIFT) #define MPIDR_TO_SGI_CLUSTER_ID(mpidr) ((mpidr) & ~0xFUL) +/* + * gic_starting_cpu() is called after the last point where cpuhp is allowed + * to fail. So pre check for problems earlier. + */ +static int gic_check_rdist(unsigned int cpu) +{ + if (cpumask_test_cpu(cpu, &broken_rdists)) + return -EINVAL; + + return 0; +} + static int gic_starting_cpu(unsigned int cpu) { gic_cpu_init(); @@ -1384,6 +1398,10 @@ static void __init gic_smp_init(void) }; int base_sgi; + cpuhp_setup_state_nocalls(CPUHP_BP_PREPARE_DYN, + "irqchip/arm/gicv3:checkrdist", + gic_check_rdist, NULL); + cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING, "irqchip/arm/gicv3:starting", gic_starting_cpu, NULL); @@ -2365,9 +2383,25 @@ gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header, u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2; void __iomem *redist_base; - if (!acpi_gicc_is_usable(gicc)) + /* Neither enabled or online capable means it doesn't exist, skip it */ + if (!(gicc->flags & (ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE))) 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)) { + int cpu = get_cpu_for_acpi_id(gicc->uid); + + pr_warn("CPU %u's redistributor is inaccessible: this CPU can't be brought online\n", cpu); + if (cpu >= 0) + cpumask_set_cpu(cpu, &broken_rdists); + return 0; + } + redist_base = ioremap(gicc->gicr_base_address, size); if (!redist_base) return -ENOMEM; @@ -2413,9 +2447,12 @@ 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; @@ -2474,7 +2511,8 @@ static int __init gic_acpi_parse_virt_madt_gicc(union acpi_subtable_headers *hea int maint_irq_mode; static int first_madt = true; - if (!acpi_gicc_is_usable(gicc)) + if (!(gicc->flags & + (ACPI_MADT_ENABLED | ACPI_MADT_GICC_ONLINE_CAPABLE))) return 0; maint_irq_mode = (gicc->flags & ACPI_MADT_VGIC_IRQ_MODE) ? diff --git a/include/linux/acpi.h b/include/linux/acpi.h index fd45bfab66b8..9f8c9d29b035 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -237,11 +237,6 @@ acpi_table_parse_cedt(enum acpi_cedt_type id, int acpi_parse_mcfg (struct acpi_table_header *header); 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; -} - #if defined(CONFIG_X86) || defined(CONFIG_LOONGARCH) void acpi_numa_processor_affinity_init (struct acpi_srat_cpu_affinity *pa); #else From 643e12da4a4983a34658e33f2b1581caee9cac8c Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Wed, 29 May 2024 14:34:42 +0100 Subject: [PATCH 15/21] arm64: psci: Ignore DENIED CPUs 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. Note the alternatives to the PSCI cpu_boot() callback do not return -EPERM so the change in smp.c has no affect. See https://developer.arm.com/documentation/den0022/f/?lang=en page 58. Signed-off-by: Jean-Philippe Brucker [ morse: Rewrote commit message ] Signed-off-by: James Morse Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Reviewed-by: Gavin Shan Signed-off-by: Russell King (Oracle) Signed-off-by: Jonathan Cameron Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-16-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- 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 6b0572daa9da..a755b9f902fa 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -132,7 +132,8 @@ 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 eba4675008a6e4cbff27b579a837bd29be2642de Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:43 +0100 Subject: [PATCH 16/21] arm64: arch_register_cpu() variant to check if an ACPI handle is now available. The ARM64 architecture does not support physical CPU HP today. To avoid any possibility of a bug against such an architecture if defined in future, check for the physical CPU HP case (not present) and return an error on any such attempt. On ARM64 virtual CPU Hotplug relies on the status value that can be queried via the AML method _STA for the CPU object. There are two conditions in which the CPU can be registered. 1) ACPI disabled. 2) ACPI enabled and the acpi_handle is available. _STA evaluates to the CPU is both enabled and present. (Note that in absence of the _STA method they are always in this state). If neither of these conditions is met the CPU is not 'yet' ready to be used and -EPROBE_DEFER is returned. Success occurs in the early attempt to register the CPUs if we are booting with DT (no concept yet of vCPU HP) if not it succeeds for already enabled CPUs when the ACPI Processor driver attaches to them. Finally it may succeed via the CPU Hotplug code indicating that the CPU is now enabled. For ACPI if CONFIG_ACPI_PROCESSOR the only path to get to arch_register_cpu() with that handle set is via acpi_processor_hot_add_init() which is only called from an ACPI bus scan in which _STA has already been queried there is no need to repeat it here. Add a comment to remind us of this in the future. Suggested-by: Rafael J. Wysocki Tested-by: Miguel Luis Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-17-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/kernel/smp.c | 53 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index a755b9f902fa..1c84375f978e 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -511,6 +511,59 @@ static int __init smp_cpu_setup(int cpu) static bool bootcpu_valid __initdata; static unsigned int cpu_count = 1; +int arch_register_cpu(int cpu) +{ + acpi_handle acpi_handle = acpi_get_processor_handle(cpu); + struct cpu *c = &per_cpu(cpu_devices, cpu); + + if (!acpi_disabled && !acpi_handle && + IS_ENABLED(CONFIG_ACPI_HOTPLUG_CPU)) + return -EPROBE_DEFER; + +#ifdef CONFIG_ACPI_HOTPLUG_CPU + /* For now block anything that looks like physical CPU Hotplug */ + if (invalid_logical_cpuid(cpu) || !cpu_present(cpu)) { + pr_err_once("Changing CPU present bit is not supported\n"); + return -ENODEV; + } +#endif + + /* + * Availability of the acpi handle is sufficient to establish + * that _STA has aleady been checked. No need to recheck here. + */ + c->hotpluggable = arch_cpu_is_hotpluggable(cpu); + + return register_cpu(c, cpu); +} + +#ifdef CONFIG_ACPI_HOTPLUG_CPU +void arch_unregister_cpu(int cpu) +{ + acpi_handle acpi_handle = acpi_get_processor_handle(cpu); + struct cpu *c = &per_cpu(cpu_devices, cpu); + acpi_status status; + unsigned long long sta; + + if (!acpi_handle) { + pr_err_once("Removing a CPU without associated ACPI handle\n"); + return; + } + + status = acpi_evaluate_integer(acpi_handle, "_STA", NULL, &sta); + if (ACPI_FAILURE(status)) + return; + + /* For now do not allow anything that looks like physical CPU HP */ + if (cpu_present(cpu) && !(sta & ACPI_STA_DEVICE_PRESENT)) { + pr_err_once("Changing CPU present bit is not supported\n"); + return; + } + + unregister_cpu(c); +} +#endif /* CONFIG_ACPI_HOTPLUG_CPU */ + #ifdef CONFIG_ACPI static struct acpi_madt_generic_interrupt cpu_madt_gicc[NR_CPUS]; From 9d0873892f4d4bf62a351897e91e5169b4c6f4aa Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 29 May 2024 14:34:44 +0100 Subject: [PATCH 17/21] arm64: Kconfig: Enable hotplug CPU on arm64 if ACPI_PROCESSOR is enabled. In order to move arch_register_cpu() to be called via the same path for initially present CPUs described by ACPI and hotplugged CPUs ACPI_HOTPLUG_CPU needs to be enabled. The protection against invalid IDs in acpi_map_cpu() is needed as at least one production BIOS is in the wild which reports entries in DSDT (with no _STA method, so assumed enabled and present) that don't match MADT. Tested-by: Miguel Luis Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-18-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/Kconfig | 1 + arch/arm64/kernel/acpi.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5d91259ee7b5..e8f2ef2312db 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -5,6 +5,7 @@ config ARM64 select ACPI_CCA_REQUIRED if ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_GTDT if ACPI + select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR select ACPI_IORT if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ACPI_MCFG if (ACPI && PCI) diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index e0e7b93c16cc..9360ba86678b 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -30,6 +30,7 @@ #include #include +#include #include #include #include @@ -423,6 +424,27 @@ void arch_reserve_mem_area(acpi_physical_address addr, size_t size) memblock_mark_nomap(addr, size); } +#ifdef CONFIG_ACPI_HOTPLUG_CPU +int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 apci_id, + int *pcpu) +{ + /* If an error code is passed in this stub can't fix it */ + if (*pcpu < 0) { + pr_warn_once("Unable to map CPU to valid ID\n"); + return *pcpu; + } + + return 0; +} +EXPORT_SYMBOL(acpi_map_cpu); + +int acpi_unmap_cpu(int cpu) +{ + return 0; +} +EXPORT_SYMBOL(acpi_unmap_cpu); +#endif /* CONFIG_ACPI_HOTPLUG_CPU */ + #ifdef CONFIG_ACPI_FFH /* * Implements ARM64 specific callbacks to support ACPI FFH Operation Region as From 828ce929d1c3aff0e9a330fea40d29980e17e256 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:45 +0100 Subject: [PATCH 18/21] arm64: document virtual CPU hotplug's expectations 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 Reviewed-by: Jonathan Cameron Signed-off-by: Russell King (Oracle) Tested-by: Miguel Luis Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-19-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- 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 4e1a7df4548003fc081360b0f4edce3f7a991bfc Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 29 May 2024 14:34:46 +0100 Subject: [PATCH 19/21] cpumask: Add enabled cpumask for present CPUs that can be brought online 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 Tested-by: Miguel Luis Tested-by: Vishnu Pajjuri Tested-by: Jianyong Wu Acked-by: Thomas Gleixner Signed-off-by: Russell King (Oracle) Reviewed-by: Gavin Shan Signed-off-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240529133446.28446-20-Jonathan.Cameron@huawei.com Signed-off-by: Catalin Marinas --- .../ABI/testing/sysfs-devices-system-cpu | 6 +++++ drivers/base/cpu.c | 10 ++++++++ include/linux/cpumask.h | 25 +++++++++++++++++++ kernel/cpu.c | 3 +++ 4 files changed, 44 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index e7e160954e79..53ed1a803422 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -694,3 +694,9 @@ Description: (RO) indicates whether or not the kernel directly supports modifying the crash elfcorehdr for CPU hot un/plug and/or on/offline changes. + +What: /sys/devices/system/cpu/enabled +Date: Nov 2022 +Contact: Linux kernel mailing list +Description: + (RO) the list of CPUs that can be brought online. diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 1487cd9761a4..b57326fd48d4 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 23686bed441d..954d4adc8f81 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -93,6 +93,7 @@ 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 * @@ -125,11 +126,13 @@ 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) @@ -1075,6 +1078,7 @@ 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 @@ -1092,6 +1096,15 @@ 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) { @@ -1173,6 +1186,7 @@ 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) @@ -1181,6 +1195,11 @@ 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); @@ -1205,6 +1224,7 @@ 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 @@ -1218,6 +1238,11 @@ 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 563877d6c28b..a2f3ad276814 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -3069,6 +3069,9 @@ 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); From 46800e38ef0e45a73839ded0347885ada2b4f7bb Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Mon, 1 Jul 2024 10:11:32 +1000 Subject: [PATCH 20/21] arm64: Kconfig: Fix dependencies to enable ACPI_HOTPLUG_CPU MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Both ACPI_PROCESSOR and HOTPLUG_CPU are needed by ACPI_HOTPLUG_CPU. Otherwise, we can have compiling error with the following configurations. CONFIG_HOTPLUG_CPU=n CONFIG_ACPI_PROCESSOR=y CONFIG_ACPI_HOTPLUG_CPU=y arch/arm64/kernel/smp.c: In function ‘arch_unregister_cpu’: arch/arm64/kernel/smp.c:563:9: error: implicit declaration of \ function ‘unregister_cpu’; did you mean ‘register_cpu’? \ [-Werror=implicit-function-declaration] 563 | unregister_cpu(c); | ^~~~~~~~~~~~~~ | register_cpu Fix it by enabling ACPI_HOTPLUG_CPU when both ACPI_PROCESSOR and HOTPLUG_CPU are enabled, consistent with other architectures like x86 and loongarch. Fixes: 9d0873892f4d ("arm64: Kconfig: Enable hotplug CPU on arm64 if ACPI_PROCESSOR is enabled.") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202406300437.XnuW0n34-lkp@intel.com/ Signed-off-by: Gavin Shan Acked-by: Jonathan Cameron Link: https://lore.kernel.org/r/20240701001132.1585153-1-gshan@redhat.com Signed-off-by: Catalin Marinas --- arch/arm64/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e8f2ef2312db..ff17c5705324 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -5,7 +5,7 @@ config ARM64 select ACPI_CCA_REQUIRED if ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_GTDT if ACPI - select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR + select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU select ACPI_IORT if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI select ACPI_MCFG if (ACPI && PCI) From 080402007007ca1bed8bcb103625137a5c8446c6 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Fri, 5 Jul 2024 12:54:29 +0100 Subject: [PATCH 21/21] irqchip/gic-v3: Fix 'broken_rdists' unused warning when !SMP and !ACPI Compiling the GICv3 driver on arm32 with CONFIG_SMP disabled (CONFIG_ACPI is not available) generates an unused variable warning for 'broken_rdists'. Add a __maybe_unused attribute to silence the compiler. Fixes: d633da5d3ab1 ("irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs") Cc: # .x Acked-by: Marc Zyngier Signed-off-by: Catalin Marinas --- drivers/irqchip/irq-gic-v3.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index cc81515c1413..18619d29b2ed 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -44,7 +44,7 @@ #define GIC_IRQ_TYPE_PARTITION (GIC_IRQ_TYPE_LPI + 1) -static struct cpumask broken_rdists __read_mostly; +static struct cpumask broken_rdists __read_mostly __maybe_unused; struct redist_region { void __iomem *redist_base;