mainline inclusion from mainline-v7.0-rc1 commit 13ebeef6a1b9c4e5c9789f835cc4ec34873f0bb1 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9134 CVE: NA Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... ---------------------------------------------------------------------- Currently, the ACPI idle driver is registered from within a CPU hotplug callback. Although this didn't cause any functional issues, this is questionable and confusing. And it is better to register the cpuidle driver when all of the CPUs have been brought up. So add a new function to initialize acpi_idle_driver based on the power management information of an available CPU and register cpuidle driver in acpi_processor_driver_init(). This commit has four changes under the commit 7a8c994cbb2d (ACPI: processor: idle: Optimize ACPI idle driver registration): 1) move acpi_processor_register_idle_driver() ahead of the driver_register(). 2) add acpi_processor_cstate_first_run_checks() before calling acpi_processor_get_power_info(). 3) squash the commit 9d68320b2bca (ACPI: processor: idle: Fix function defined but not used warning) into this change. 4) use for_each_possible_cpu(cpu) to scan all possible cpus. Signed-off-by: Huisong Li <lihuisong@huawei.com> Tested-by: Borislav Petkov (AMD) <bp@alien8.de> [ rjw: New comment edits, changelog tweak ] Link: https://patch.msgid.link/20251223100914.2407069-2-lihuisong@huawei.com Signed-off-by: Huisong Li <lihuisong@huawei.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- drivers/acpi/processor_driver.c | 9 ++++- drivers/acpi/processor_idle.c | 66 +++++++++++++++++++++------------ include/acpi/processor.h | 2 + 3 files changed, 53 insertions(+), 24 deletions(-) diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 4bd16b3f0781..63ad8d8cb9e0 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -269,9 +269,11 @@ static int __init acpi_processor_driver_init(void) acpi_processor_ignore_ppc_init(); } + acpi_processor_register_idle_driver(); + result = driver_register(&acpi_processor_driver); if (result < 0) - return result; + goto unregister_idle_drv;; result = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "acpi/cpu-drv:online", @@ -286,6 +288,10 @@ static int __init acpi_processor_driver_init(void) return 0; err: driver_unregister(&acpi_processor_driver); + +unregister_idle_drv: + acpi_processor_unregister_idle_driver(); + return result; } @@ -303,6 +309,7 @@ static void __exit acpi_processor_driver_exit(void) cpuhp_remove_state_nocalls(hp_online); cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD); driver_unregister(&acpi_processor_driver); + acpi_processor_unregister_idle_driver(); } module_init(acpi_processor_driver_init); diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 709e1228e408..a191a9843418 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1387,7 +1387,49 @@ int acpi_processor_power_state_has_changed(struct acpi_processor *pr) return 0; } -static int acpi_processor_registered; +void acpi_processor_register_idle_driver(void) +{ + struct acpi_processor *pr; + int ret = -ENODEV; + int cpu; + + /* + * ACPI idle driver is used by all possible CPUs. + * Use the processor power info of one in them to set up idle states. + * Note that the existing idle handler will be used on platforms that + * only support C1. + */ + for_each_possible_cpu(cpu) { + pr = per_cpu(processors, cpu); + if (!pr) + continue; + + acpi_processor_cstate_first_run_checks(); + ret = acpi_processor_get_power_info(pr); + if (!ret) { + pr->flags.power_setup_done = 1; + acpi_processor_setup_cpuidle_states(pr); + break; + } + } + + if (ret) { + pr_debug("No ACPI power information from any CPUs.\n"); + return; + } + + ret = cpuidle_register_driver(&acpi_idle_driver); + if (ret) { + pr_debug("register %s failed.\n", acpi_idle_driver.name); + return; + } + pr_debug("%s registered with cpuidle.\n", acpi_idle_driver.name); +} + +void acpi_processor_unregister_idle_driver(void) +{ + cpuidle_unregister_driver(&acpi_idle_driver); +} int acpi_processor_power_init(struct acpi_processor *pr) { @@ -1402,22 +1444,7 @@ int acpi_processor_power_init(struct acpi_processor *pr) if (!acpi_processor_get_power_info(pr)) pr->flags.power_setup_done = 1; - /* - * Install the idle handler if processor power management is supported. - * Note that we use previously set idle handler will be used on - * platforms that only support C1. - */ if (pr->flags.power) { - /* Register acpi_idle_driver if not already registered */ - if (!acpi_processor_registered) { - acpi_processor_setup_cpuidle_states(pr); - retval = cpuidle_register_driver(&acpi_idle_driver); - if (retval) - return retval; - pr_debug("%s registered with cpuidle\n", - acpi_idle_driver.name); - } - dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return -ENOMEM; @@ -1430,14 +1457,11 @@ int acpi_processor_power_init(struct acpi_processor *pr) */ retval = cpuidle_register_device(dev); if (retval) { - if (acpi_processor_registered == 0) - cpuidle_unregister_driver(&acpi_idle_driver); per_cpu(acpi_cpuidle_device, pr->id) = NULL; kfree(dev); return retval; } - acpi_processor_registered++; } return 0; } @@ -1451,10 +1475,6 @@ int acpi_processor_power_exit(struct acpi_processor *pr) if (pr->flags.power) { cpuidle_unregister_device(dev); - acpi_processor_registered--; - if (acpi_processor_registered == 0) - cpuidle_unregister_driver(&acpi_idle_driver); - kfree(dev); } diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 3f34ebb27525..f85bbb7b8c6c 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -418,6 +418,8 @@ int acpi_processor_power_init(struct acpi_processor *pr); int acpi_processor_power_exit(struct acpi_processor *pr); int acpi_processor_power_state_has_changed(struct acpi_processor *pr); int acpi_processor_hotplug(struct acpi_processor *pr); +void acpi_processor_register_idle_driver(void); +void acpi_processor_unregister_idle_driver(void); #else static inline int acpi_processor_power_init(struct acpi_processor *pr) { -- 2.33.0