On 2/12/21 8:55 AM, shuo.a.liu@xxxxxxxxx wrote:
> From: Shuo Liu <shuo.a.liu@xxxxxxxxx>
>
> 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")
> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Signed-off-by: Shuo Liu <shuo.a.liu@xxxxxxxxx>
> ---
> I followed Greg's idea that add {add,remove}_cpu() functions prototypes.
> The v2 solution is different from the v1, so i removed Randy's Acked-by.
> Randy, please help have a look on v2.
>
> v2:
> - Drop the #ifdef in .c solution. Add {add,remove}_cpu() prototypes. (Suggested by Greg)
>
> include/linux/cpu.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/include/linux/cpu.h b/include/linux/cpu.h
> index 3aaa0687e8df..94a578a96202 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; }
I would have done: return 0;
Anyway:
Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested
> static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
> #endif /* !CONFIG_HOTPLUG_CPU */
thanks.
--
~Randy
