Re: [PATCH] x86/jailhouse: fix building without X86_X2APIC

[Dou Liyang <douly.fnst@cn.fujitsu.com>]

Hi Arnd,

At 01/16/2018 04:23 AM, Arnd Bergmann wrote:
> When CONFIG_X86_X2APIC is disabled, jailhouse fails to build:
> 
> arch/x86/kernel/jailhouse.c: In function 'jailhouse_get_smp_config':
> arch/x86/kernel/jailhouse.c:73:3: error: 'x2apic_phys' undeclared (first use in this function); did you mean 'x2apic_mode'?
> 
> The code is protected by an appropriate x2apic_enabled() check that leads
> to the assignment being optimized out without a link-time reference to
> x2apic_phys, so we just lack a declaration.
> 
> Let's move x2apic_mode and x2apic_phys outside of the #ifdef together,
> for consistency.
> 
> Fixes: 11c8dc419bbc ("x86/jailhouse: Enable APIC and SMP support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   arch/x86/include/asm/apic.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
> index 98722773391d..0317d635d9ba 100644
> --- a/arch/x86/include/asm/apic.h
> +++ b/arch/x86/include/asm/apic.h
> @@ -188,6 +188,8 @@ static inline void lapic_assign_system_vectors(void) { }
>   static inline void lapic_assign_legacy_vector(unsigned int i, bool r) { }
>   #endif /* !CONFIG_X86_LOCAL_APIC */
>   
> +extern int x2apic_mode;
> +extern int x2apic_phys;
We can't do that, adding a macro for the X2APIC=n case is enough

Thanks,
	dou

-------------------------8<----------------------

Subject: [PATCH] x86/apic: Add a macro named x2apic_phys for the 
X2APIC=n case

The x86 system may build failed in the X2APIC=n case, due to the missing of
x2apic_phys.

So add a macro named x2apic_phys for the X2APIC=n case.

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
---
  arch/x86/include/asm/apic.h | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index a9e57f08bfa6..ca5940fb995a 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -264,7 +264,8 @@ static inline void x2apic_setup(void) { }
  static inline int x2apic_enabled(void) { return 0; }

  #define x2apic_mode		(0)
-#define	x2apic_supported()	(0)
+#define x2apic_phys		(0)
+#define x2apic_supported()	(0)
  #endif /* !CONFIG_X86_X2APIC */

  struct irq_data;
--