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authorThomas Gleixner <tglx@linutronix.de>2023-05-13 00:07:04 +0300
committerPeter Zijlstra <peterz@infradead.org>2023-05-15 14:44:49 +0300
commite59e74dc48a309cb848ffc3d76a0d61aa6803c05 (patch)
tree9e58c48aff3090ed62f0d81d0f7443160ba82ed7 /arch/x86/power
parent666e1156b2c514f045827f50263ed2eb9d78671b (diff)
downloadlinux-e59e74dc48a309cb848ffc3d76a0d61aa6803c05.tar.xz
x86/topology: Remove CPU0 hotplug option
This was introduced together with commit e1c467e69040 ("x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI") to eventually support physical hotplug of CPU0: "We'll change this code in the future to wake up hard offlined CPU0 if real platform and request are available." 11 years later this has not happened and physical hotplug is not officially supported. Remove the cruft. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Tested-by: Helge Deller <deller@gmx.de> # parisc Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com> # Steam Deck Link: https://lore.kernel.org/r/20230512205255.715707999@linutronix.de
Diffstat (limited to 'arch/x86/power')
-rw-r--r--arch/x86/power/cpu.c37
1 files changed, 0 insertions, 37 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 7a4d5e911415..63230ff8cf4f 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -351,43 +351,6 @@ static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
case PM_HIBERNATION_PREPARE:
ret = bsp_check();
break;
-#ifdef CONFIG_DEBUG_HOTPLUG_CPU0
- case PM_RESTORE_PREPARE:
- /*
- * When system resumes from hibernation, online CPU0 because
- * 1. it's required for resume and
- * 2. the CPU was online before hibernation
- */
- if (!cpu_online(0))
- _debug_hotplug_cpu(0, 1);
- break;
- case PM_POST_RESTORE:
- /*
- * When a resume really happens, this code won't be called.
- *
- * This code is called only when user space hibernation software
- * prepares for snapshot device during boot time. So we just
- * call _debug_hotplug_cpu() to restore to CPU0's state prior to
- * preparing the snapshot device.
- *
- * This works for normal boot case in our CPU0 hotplug debug
- * mode, i.e. CPU0 is offline and user mode hibernation
- * software initializes during boot time.
- *
- * If CPU0 is online and user application accesses snapshot
- * device after boot time, this will offline CPU0 and user may
- * see different CPU0 state before and after accessing
- * the snapshot device. But hopefully this is not a case when
- * user debugging CPU0 hotplug. Even if users hit this case,
- * they can easily online CPU0 back.
- *
- * To simplify this debug code, we only consider normal boot
- * case. Otherwise we need to remember CPU0's state and restore
- * to that state and resolve racy conditions etc.
- */
- _debug_hotplug_cpu(0, 0);
- break;
-#endif
default:
break;
}