Re: linux-next: Tree for July 27 (xen)

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Tue, 27 Jul 2010, Randy Dunlap wrote:
> Stephen Rothwell wrote:
> > Hi all,
> > 
> > Changes since 20100726:
> > 
> > 
> > The xen tree lost its build problems but gained a conflict against Linus'
> > tree.
> 
> when X86_32=y, SMP=n, X86_LOCAL_APIC=n:
> 
> drivers/built-in.o: In function `xen_callback_vector':
> (.text+0x41238): undefined reference to `first_system_vector'
> 
> alloc_intr_gate() calls alloc_system_vector(), which uses first_system_vector.

this patch should solve the issue:

---

alloc_system_vector: access first_system_vector when X86_LOCAL_APIC=y

Currently alloc_system_vector reads and writes first_system_vector
unconditionally while first_system_vector is only defined when
CONFIG_X86_LOCAL_APIC=y.
This patch makes sure first_system_vector is accessed only in that case.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 617bd56..f83e055 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -341,8 +341,10 @@ static inline void alloc_system_vector(int vector)
 {
 	if (!test_bit(vector, used_vectors)) {
 		set_bit(vector, used_vectors);
+#if defined(CONFIG_X86_LOCAL_APIC)
 		if (first_system_vector > vector)
 			first_system_vector = vector;
+#endif
 	} else
 		BUG();
 }