[PATCH v2] MIPS: SMP-CPS: fix build error when HOTPLUG_CPU not set

From: Randy Dunlap
Date: Fri Feb 17 2023 - 15:07:56 EST


When MIPS_CPS=y, MIPS_CPS_PM is not set, HOTPLUG_CPU is not set, and
KEXEC=y, cps_shutdown_this_cpu() attempts to call cps_pm_enter_state(),
which is not built when MIPS_CPS_PM is not set.
Conditionally execute the else branch based on CONFIG_HOTPLUG_CPU
to remove the build error.
This build failure is from a randconfig file.

mips-linux-ld: arch/mips/kernel/smp-cps.o: in function `$L162':
smp-cps.c:(.text.cps_kexec_nonboot_cpu+0x31c): undefined reference to `cps_pm_enter_state'

Fixes: 1447864bee4c ("MIPS: kexec: CPS systems to halt nonboot CPUs")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Dengcheng Zhu <dzhu@xxxxxxxxxxxx>
Cc: Paul Burton <paulburton@xxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxx>
---
v2: use IS_ENABLED() instead of #ifdef-ery (Sergei)

arch/mips/kernel/smp-cps.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff -- a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -424,9 +424,11 @@ static void cps_shutdown_this_cpu(enum c
wmb();
}
} else {
- pr_debug("Gating power to core %d\n", core);
- /* Power down the core */
- cps_pm_enter_state(CPS_PM_POWER_GATED);
+ if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) {
+ pr_debug("Gating power to core %d\n", core);
+ /* Power down the core */
+ cps_pm_enter_state(CPS_PM_POWER_GATED);
+ }
}
}