From 51f24030358bdeeb9e75a38618dd029c5a53beeb Mon Sep 17 00:00:00 2001 From: Shuo Liu Date: Sun, 21 Feb 2021 21:43:38 +0800 Subject: [PATCH] cpu/hotplug: Fix build error of using {add,remove}_cpu() with !CONFIG_SMP MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 279dcf693ac7 ("virt: acrn: Introduce an interface for Service VM to control vCPU") introduced {add,remove}_cpu() usage and it hit below error with !CONFIG_SMP: ../drivers/virt/acrn/hsm.c: In function ‘remove_cpu_store’: ../drivers/virt/acrn/hsm.c:389:3: error: implicit declaration of function ‘remove_cpu’; [-Werror=implicit-function-declaration] remove_cpu(cpu); ../drivers/virt/acrn/hsm.c:402:2: error: implicit declaration of function ‘add_cpu’; [-Werror=implicit-function-declaration] add_cpu(cpu); Add add_cpu() function prototypes with !CONFIG_SMP and remove_cpu() with !CONFIG_HOTPLUG_CPU for such usage. Fixes: 279dcf693ac7 ("virt: acrn: Introduce an interface for Service VM to control vCPU") Cc: Stephen Rothwell Cc: Thomas Gleixner Cc: Greg Kroah-Hartman Cc: Qais Yousef Reported-by: Randy Dunlap Reviewed-by: Qais Yousef Acked-by: Randy Dunlap # build-tested Signed-off-by: Shuo Liu Link: https://lore.kernel.org/r/20210221134339.57851-1-shuo.a.liu@intel.com Signed-off-by: Greg Kroah-Hartman --- include/linux/cpu.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 3aaa068..94a578a 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -108,6 +108,8 @@ static inline void cpu_maps_update_done(void) { } +static inline int add_cpu(unsigned int cpu) { return 0;} + #endif /* CONFIG_SMP */ extern struct bus_type cpu_subsys; @@ -137,6 +139,7 @@ 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 int remove_cpu(unsigned int cpu) { return -EPERM; } static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } #endif /* !CONFIG_HOTPLUG_CPU */ -- 2.7.4