diff options
Diffstat (limited to 'arch/x86/power')
| -rw-r--r-- | arch/x86/power/cpu.c | 10 | ||||
| -rw-r--r-- | arch/x86/power/hibernate_64.c | 33 |
2 files changed, 43 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index a7d966964c6f..513ce09e9950 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -299,7 +299,17 @@ int hibernate_resume_nonboot_cpu_disable(void) * address in its instruction pointer may not be possible to resolve * any more at that point (the page tables used by it previously may * have been overwritten by hibernate image data). + * + * First, make sure that we wake up all the potentially disabled SMT + * threads which have been initially brought up and then put into + * mwait/cpuidle sleep. + * Those will be put to proper (not interfering with hibernation + * resume) sleep afterwards, and the resumed kernel will decide itself + * what to do with them. */ + ret = cpuhp_smt_enable(); + if (ret) + return ret; smp_ops.play_dead = resume_play_dead; ret = disable_nonboot_cpus(); smp_ops.play_dead = play_dead; diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c index 0ef5e5204968..9c80966c80ba 100644 --- a/arch/x86/power/hibernate_64.c +++ b/arch/x86/power/hibernate_64.c @@ -13,6 +13,7 @@ #include <linux/suspend.h> #include <linux/scatterlist.h> #include <linux/kdebug.h> +#include <linux/cpu.h> #include <crypto/hash.h> @@ -347,3 +348,35 @@ int arch_hibernation_header_restore(void *addr) return 0; } + +int arch_resume_nosmt(void) +{ + int ret = 0; + /* + * We reached this while coming out of hibernation. This means + * that SMT siblings are sleeping in hlt, as mwait is not safe + * against control transition during resume (see comment in + * hibernate_resume_nonboot_cpu_disable()). + * + * If the resumed kernel has SMT disabled, we have to take all the + * SMT siblings out of hlt, and offline them again so that they + * end up in mwait proper. + * + * Called with hotplug disabled. + */ + cpu_hotplug_enable(); + if (cpu_smt_control == CPU_SMT_DISABLED || + cpu_smt_control == CPU_SMT_FORCE_DISABLED) { + enum cpuhp_smt_control old = cpu_smt_control; + + ret = cpuhp_smt_enable(); + if (ret) + goto out; + ret = cpuhp_smt_disable(old); + if (ret) + goto out; + } +out: + cpu_hotplug_disable(); + return ret; +} |