From: "tip-bot2 for Qais Yousef" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Qais Yousef <qais.yousef@arm.com>,
Thomas Gleixner <tglx@linutronix.de>, x86 <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [tip: smp/core] cpu/hotplug: Create a new function to shutdown nonboot cpus
Date: Wed, 25 Mar 2020 12:06:06 -0000 [thread overview]
Message-ID: <158513796687.28353.802984004704044880.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20200323135110.30522-3-qais.yousef@arm.com>
The following commit has been merged into the smp/core branch of tip:
Commit-ID: 0441a5597c5d02ed7abed1d989eaaa1595dedac5
Gitweb: https://git.kernel.org/tip/0441a5597c5d02ed7abed1d989eaaa1595dedac5
Author: Qais Yousef <qais.yousef@arm.com>
AuthorDate: Mon, 23 Mar 2020 13:50:55
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 25 Mar 2020 12:59:31 +01:00
cpu/hotplug: Create a new function to shutdown nonboot cpus
This function will be used later in machine_shutdown() for some
architectures.
disable_nonboot_cpus() is not safe to use when doing machine_down(),
because it relies on freeze_secondary_cpus() which in turn is a
suspend/resume related freeze and could abort if the logic detects any
pending activities that can prevent finishing the offlining process.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200323135110.30522-3-qais.yousef@arm.com
---
include/linux/cpu.h | 2 ++
kernel/cpu.c | 42 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 44 insertions(+)
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index cf8cf38..64a246e 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -120,6 +120,7 @@ extern void cpu_hotplug_enable(void);
void clear_tasks_mm_cpumask(int cpu);
int cpu_down(unsigned int cpu);
int remove_cpu(unsigned int cpu);
+extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
#else /* CONFIG_HOTPLUG_CPU */
@@ -131,6 +132,7 @@ static inline int cpus_read_trylock(void) { return true; }
static inline void lockdep_assert_cpus_held(void) { }
static inline void cpu_hotplug_disable(void) { }
static inline void cpu_hotplug_enable(void) { }
+static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
#endif /* !CONFIG_HOTPLUG_CPU */
/* Wrappers which go away once all code is converted */
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 069802f..03c7271 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1069,6 +1069,48 @@ int remove_cpu(unsigned int cpu)
}
EXPORT_SYMBOL_GPL(remove_cpu);
+void smp_shutdown_nonboot_cpus(unsigned int primary_cpu)
+{
+ unsigned int cpu;
+ int error;
+
+ cpu_maps_update_begin();
+
+ /*
+ * Make certain the cpu I'm about to reboot on is online.
+ *
+ * This is inline to what migrate_to_reboot_cpu() already do.
+ */
+ if (!cpu_online(primary_cpu))
+ primary_cpu = cpumask_first(cpu_online_mask);
+
+ for_each_online_cpu(cpu) {
+ if (cpu == primary_cpu)
+ continue;
+
+ error = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
+ if (error) {
+ pr_err("Failed to offline CPU%d - error=%d",
+ cpu, error);
+ break;
+ }
+ }
+
+ /*
+ * Ensure all but the reboot CPU are offline.
+ */
+ BUG_ON(num_online_cpus() > 1);
+
+ /*
+ * Make sure the CPUs won't be enabled by someone else after this
+ * point. Kexec will reboot to a new kernel shortly resetting
+ * everything along the way.
+ */
+ cpu_hotplug_disabled++;
+
+ cpu_maps_update_done();
+}
+
#else
#define takedown_cpu NULL
#endif /*CONFIG_HOTPLUG_CPU*/
next prev parent reply other threads:[~2020-03-25 12:06 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-23 13:50 [PATCH v4 00/17] Convert cpu_up/down to device_online/offline Qais Yousef
2020-03-23 13:50 ` [PATCH v4 01/17] cpu: Add new {add,remove}_cpu() functions Qais Yousef
2020-03-23 15:00 ` Paul E. McKenney
2020-03-25 12:06 ` [tip: smp/core] cpu/hotplug: " tip-bot2 for Qais Yousef
2020-03-23 13:50 ` [PATCH v4 02/17] smp: Create a new function to shutdown nonboot cpus Qais Yousef
2020-03-25 12:06 ` tip-bot2 for Qais Yousef [this message]
2020-03-23 13:50 ` [PATCH v4 03/17] ia64: Replace cpu_down with smp_shutdown_nonboot_cpus() Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] ia64: Replace cpu_down() " tip-bot2 for Qais Yousef
2020-03-23 13:50 ` [PATCH v4 04/17] arm: Don't use disable_nonboot_cpus() Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] ARM: " tip-bot2 for Qais Yousef
2020-03-23 13:50 ` [PATCH v4 05/17] arm: Use reboot_cpu instead of hardcoding it to 0 Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] ARM: " tip-bot2 for Qais Yousef
2020-03-23 13:50 ` [PATCH v4 06/17] arm64: Don't use disable_nonboot_cpus() Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] " tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 07/17] arm64: Use reboot_cpu instead of hardconding it to 0 Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] " tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 08/17] arm64: hibernate.c: Create a new function to handle cpu_up(sleep_cpu) Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] arm64: hibernate: Use bringup_hibernate_cpu() tip-bot2 for Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] cpu/hotplug: Provide bringup_hibernate_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 09/17] x86: Replace cpu_up/down with add/remove_cpu Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] x86/smp: Replace cpu_up/down() with add/remove_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 10/17] powerpc: Replace cpu_up/down with add/remove_cpu Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] powerpc: Replace cpu_up/down() with add/remove_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 11/17] sparc: Replace cpu_up/down with add/remove_cpu Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] sparc: Replace cpu_up/down() with add/remove_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 12/17] parisc: Replace cpu_up/down with add/remove_cpu Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] parisc: Replace cpu_up/down() with add/remove_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 13/17] driver: xen: Replace cpu_up/down with device_online/offline Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] xen/cpuhotplug: Replace cpu_up/down() with device_online/offline() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 14/17] firmware: psci: Replace cpu_up/down with add/remove_cpu Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] firmware: psci: Replace cpu_up/down() with add/remove_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 15/17] torture: Replace cpu_up/down with add/remove_cpu Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] torture: Replace cpu_up/down() with add/remove_cpu() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 16/17] smp: Create a new function to bringup nonboot cpus online Qais Yousef
2020-03-25 12:06 ` [tip: smp/core] cpu/hotplug: Move bringup of secondary CPUs out of smp_init() tip-bot2 for Qais Yousef
2020-03-23 13:51 ` [PATCH v4 17/17] cpu: Hide cpu_up/down Qais Yousef
2020-03-25 12:05 ` [tip: smp/core] cpu/hotplug: Hide cpu_up/down() tip-bot2 for Qais Yousef
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