diff options
| author | Qais Yousef <qais.yousef@arm.com> | 2020-03-23 13:51:01 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-03-25 12:59:34 +0100 |
| commit | d720f98604391dab6aa3cb4c1bc005ed1aba4703 (patch) | |
| tree | 4aa30be79a98f962c38b731a507add852860d9db /kernel/cpu.c | |
| parent | 5efbe6a6e1c077b4022d9e89d79543c6106c6e25 (diff) | |
| download | linux-d720f98604391dab6aa3cb4c1bc005ed1aba4703.tar.bz2 | |
cpu/hotplug: Provide bringup_hibernate_cpu()
arm64 uses cpu_up() in the resume from hibernation code to ensure that the
CPU on which the system hibernated is online. Provide a core function for
this.
[ tglx: Split out from the combo arm64 patch ]
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200323135110.30522-9-qais.yousef@arm.com
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 03c727195b65..f803678684e9 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1275,6 +1275,29 @@ int add_cpu(unsigned int cpu) } EXPORT_SYMBOL_GPL(add_cpu); +/** + * bringup_hibernate_cpu - Bring up the CPU that we hibernated on + * @sleep_cpu: The cpu we hibernated on and should be brought up. + * + * On some architectures like arm64, we can hibernate on any CPU, but on + * wake up the CPU we hibernated on might be offline as a side effect of + * using maxcpus= for example. + */ +int bringup_hibernate_cpu(unsigned int sleep_cpu) +{ + int ret; + + if (!cpu_online(sleep_cpu)) { + pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n"); + ret = cpu_up(sleep_cpu); + if (ret) { + pr_err("Failed to bring hibernate-CPU up!\n"); + return ret; + } + } + return 0; +} + #ifdef CONFIG_PM_SLEEP_SMP static cpumask_var_t frozen_cpus; |