[PATCH v2 1/2] cpu/hotplug: Remove disable_nonboot_cpus()

From: Qais Yousef
Date: Thu Apr 30 2020 - 07:40:20 EST


The single user could have called freeze_secondary_cpus() directly.

Since this function was a source of confusion, remove it as it's
just a pointless wrapper.

While at it, rename enable_nonboot_cpus() to thaw_secondary_cpus() to
preserve the naming symmetry.

Done automatically via:

git grep -l enable_nonboot_cpus | xargs sed -i 's/enable_nonboot_cpus/thaw_secondary_cpus/g'

Signed-off-by: Qais Yousef <qais.yousef@xxxxxxx>
CC: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Pavel Machek <pavel@xxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Borislav Petkov <bp@xxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: x86@xxxxxxxxxx
CC: Todd E Brandt <todd.e.brandt@xxxxxxxxxxxxxxx>
CC: linux-pm@xxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
---

Changes in v2:
* Squash Patches 2 and 3 from v1 into Patch 1 in v2.
* Instead of revert, remove __freeze_secondary_cpus() manually
(Patch 2)

v1 discussion:

https://lore.kernel.org/lkml/20200409112742.3581-1-qais.yousef@xxxxxxx/


Documentation/power/suspend-and-cpuhotplug.rst | 6 +++---
arch/x86/kernel/smpboot.c | 4 ++--
arch/x86/power/cpu.c | 2 +-
include/linux/cpu.h | 12 +++---------
include/linux/smp.h | 4 ++--
kernel/cpu.c | 14 +++++++-------
.../pm-graph/config/custom-timeline-functions.cfg | 2 +-
tools/power/pm-graph/sleepgraph.py | 2 +-
8 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/Documentation/power/suspend-and-cpuhotplug.rst b/Documentation/power/suspend-and-cpuhotplug.rst
index 572d968c5375..ebedb6c75db9 100644
--- a/Documentation/power/suspend-and-cpuhotplug.rst
+++ b/Documentation/power/suspend-and-cpuhotplug.rst
@@ -48,7 +48,7 @@ More details follow::
|
|
v
- disable_nonboot_cpus()
+ freeze_secondary_cpus()
/* start */
|
v
@@ -83,7 +83,7 @@ More details follow::
Release cpu_add_remove_lock
|
v
- /* disable_nonboot_cpus() complete */
+ /* freeze_secondary_cpus() complete */
|
v
Do suspend
@@ -93,7 +93,7 @@ More details follow::
Resuming back is likewise, with the counterparts being (in the order of
execution during resume):

-* enable_nonboot_cpus() which involves::
+* thaw_secondary_cpus() which involves::

| Acquire cpu_add_remove_lock
| Decrease cpu_hotplug_disabled, thereby enabling regular cpu hotplug
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 69881b2d446c..9c31685af55a 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1372,12 +1372,12 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
speculative_store_bypass_ht_init();
}

-void arch_enable_nonboot_cpus_begin(void)
+void arch_thaw_secondary_cpus_begin(void)
{
set_mtrr_aps_delayed_init();
}

-void arch_enable_nonboot_cpus_end(void)
+void arch_thaw_secondary_cpus_end(void)
{
mtrr_aps_init();
}
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 915bb1639763..e0a9ad8829b0 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -307,7 +307,7 @@ int hibernate_resume_nonboot_cpu_disable(void)
if (ret)
return ret;
smp_ops.play_dead = resume_play_dead;
- ret = disable_nonboot_cpus();
+ ret = freeze_secondary_cpus(0);
smp_ops.play_dead = play_dead;
return ret;
}
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index beaed2dc269e..9d34dc3b859f 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -150,12 +150,7 @@ static inline int freeze_secondary_cpus(int primary)
return __freeze_secondary_cpus(primary, true);
}

-static inline int disable_nonboot_cpus(void)
-{
- return __freeze_secondary_cpus(0, false);
-}
-
-void enable_nonboot_cpus(void);
+extern void thaw_secondary_cpus(void);

static inline int suspend_disable_secondary_cpus(void)
{
@@ -168,12 +163,11 @@ static inline int suspend_disable_secondary_cpus(void)
}
static inline void suspend_enable_secondary_cpus(void)
{
- return enable_nonboot_cpus();
+ return thaw_secondary_cpus();
}

#else /* !CONFIG_PM_SLEEP_SMP */
-static inline int disable_nonboot_cpus(void) { return 0; }
-static inline void enable_nonboot_cpus(void) {}
+static inline void thaw_secondary_cpus(void) {}
static inline int suspend_disable_secondary_cpus(void) { return 0; }
static inline void suspend_enable_secondary_cpus(void) { }
#endif /* !CONFIG_PM_SLEEP_SMP */
diff --git a/include/linux/smp.h b/include/linux/smp.h
index cbc9162689d0..04019872c7bc 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -227,8 +227,8 @@ static inline int get_boot_cpu_id(void)
*/
extern void arch_disable_smp_support(void);

-extern void arch_enable_nonboot_cpus_begin(void);
-extern void arch_enable_nonboot_cpus_end(void);
+extern void arch_thaw_secondary_cpus_begin(void);
+extern void arch_thaw_secondary_cpus_end(void);

void smp_setup_processor_id(void);

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 12ae636e9cb6..10c60e9f58b7 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1376,8 +1376,8 @@ int __freeze_secondary_cpus(int primary, bool suspend)

/*
* Make sure the CPUs won't be enabled by someone else. We need to do
- * this even in case of failure as all disable_nonboot_cpus() users are
- * supposed to do enable_nonboot_cpus() on the failure path.
+ * this even in case of failure as all freeze_secondary_cpus() users are
+ * supposed to do thaw_secondary_cpus() on the failure path.
*/
cpu_hotplug_disabled++;

@@ -1385,15 +1385,15 @@ int __freeze_secondary_cpus(int primary, bool suspend)
return error;
}

-void __weak arch_enable_nonboot_cpus_begin(void)
+void __weak arch_thaw_secondary_cpus_begin(void)
{
}

-void __weak arch_enable_nonboot_cpus_end(void)
+void __weak arch_thaw_secondary_cpus_end(void)
{
}

-void enable_nonboot_cpus(void)
+void thaw_secondary_cpus(void)
{
int cpu, error;

@@ -1405,7 +1405,7 @@ void enable_nonboot_cpus(void)

pr_info("Enabling non-boot CPUs ...\n");

- arch_enable_nonboot_cpus_begin();
+ arch_thaw_secondary_cpus_begin();

for_each_cpu(cpu, frozen_cpus) {
trace_suspend_resume(TPS("CPU_ON"), cpu, true);
@@ -1418,7 +1418,7 @@ void enable_nonboot_cpus(void)
pr_warn("Error taking CPU%d up: %d\n", cpu, error);
}

- arch_enable_nonboot_cpus_end();
+ arch_thaw_secondary_cpus_end();

cpumask_clear(frozen_cpus);
out:
diff --git a/tools/power/pm-graph/config/custom-timeline-functions.cfg b/tools/power/pm-graph/config/custom-timeline-functions.cfg
index 4f80ad7d7275..962e5768681c 100644
--- a/tools/power/pm-graph/config/custom-timeline-functions.cfg
+++ b/tools/power/pm-graph/config/custom-timeline-functions.cfg
@@ -125,7 +125,7 @@ acpi_suspend_begin:
suspend_console:
acpi_pm_prepare:
syscore_suspend:
-arch_enable_nonboot_cpus_end:
+arch_thaw_secondary_cpus_end:
syscore_resume:
acpi_pm_finish:
resume_console:
diff --git a/tools/power/pm-graph/sleepgraph.py b/tools/power/pm-graph/sleepgraph.py
index f7d1c1f62f86..530a9f681410 100755
--- a/tools/power/pm-graph/sleepgraph.py
+++ b/tools/power/pm-graph/sleepgraph.py
@@ -192,7 +192,7 @@ class SystemValues:
'suspend_console': {},
'acpi_pm_prepare': {},
'syscore_suspend': {},
- 'arch_enable_nonboot_cpus_end': {},
+ 'arch_thaw_secondary_cpus_end': {},
'syscore_resume': {},
'acpi_pm_finish': {},
'resume_console': {},
--
2.17.1