[PATCH] x86: x2apic: make stub functions available even if !CONFIG_X86_LOCAL_APIC

[PATCH] x86: x2apic: make stub functions available even if !CONFIG_X86_LOCAL_APIC

[Paolo Bonzini]

Some CONFIG_X86_X2APIC functions, especially x2apic_enabled(), are not
declared if !CONFIG_X86_LOCAL_APIC.  However, the same stubs that work
for !CONFIG_X86_X2APIC are okay even if there is no local APIC support
at all.

Avoid the introduction of #ifdefs by moving the x2apic declarations
completely outside the CONFIG_X86_LOCAL_APIC block.  (Unfortunately,
diff generation messes up the actual change that this patch makes).
There is no semantic change because CONFIG_X86_X2APIC depends on
CONFIG_X86_LOCAL_APIC.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Feng Wu <feng.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
	Failures are only visible with pending KVM changes to 4.4.
	The patch introducing them is at
	https://git.kernel.org/cgit/virt/kvm/kvm.git/commit/?h=vtd-pi&id=43ef83157e66f80a491202e5d65b225ad93d920a
	and the corresponding specification is section 9.12 of
	http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/vt-directed-io-spec.pdf
	[Posted Interrupt Descriptor (PID)].

 arch/x86/include/asm/apic.h | 110 ++++++++++++++++++++++----------------------
 1 file changed, 55 insertions(+), 55 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index ebf6d5e5668c..a30316bf801a 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -115,6 +115,59 @@ static inline bool apic_is_x2apic_enabled(void)
 	return msr & X2APIC_ENABLE;
 }
 
+extern void enable_IR_x2apic(void);
+
+extern int get_physical_broadcast(void);
+
+extern int lapic_get_maxlvt(void);
+extern void clear_local_APIC(void);
+extern void disconnect_bsp_APIC(int virt_wire_setup);
+extern void disable_local_APIC(void);
+extern void lapic_shutdown(void);
+extern void sync_Arb_IDs(void);
+extern void init_bsp_APIC(void);
+extern void setup_local_APIC(void);
+extern void init_apic_mappings(void);
+void register_lapic_address(unsigned long address);
+extern void setup_boot_APIC_clock(void);
+extern void setup_secondary_APIC_clock(void);
+extern int APIC_init_uniprocessor(void);
+
+#ifdef CONFIG_X86_64
+static inline int apic_force_enable(unsigned long addr)
+{
+	return -1;
+}
+#else
+extern int apic_force_enable(unsigned long addr);
+#endif
+
+extern int apic_bsp_setup(bool upmode);
+extern void apic_ap_setup(void);
+
+/*
+ * On 32bit this is mach-xxx local
+ */
+#ifdef CONFIG_X86_64
+extern int apic_is_clustered_box(void);
+#else
+static inline int apic_is_clustered_box(void)
+{
+	return 0;
+}
+#endif
+
+extern int setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask);
+
+#else /* !CONFIG_X86_LOCAL_APIC */
+static inline void lapic_shutdown(void) { }
+#define local_apic_timer_c2_ok		1
+static inline void init_apic_mappings(void) { }
+static inline void disable_local_APIC(void) { }
+# define setup_boot_APIC_clock x86_init_noop
+# define setup_secondary_APIC_clock x86_init_noop
+#endif /* !CONFIG_X86_LOCAL_APIC */
+
 #ifdef CONFIG_X86_X2APIC
 /*
  * Make previous memory operations globally visible before
@@ -186,67 +239,14 @@ static inline int x2apic_enabled(void)
 }
 
 #define x2apic_supported()	(cpu_has_x2apic)
-#else
+#else /* !CONFIG_X86_X2APIC */
 static inline void check_x2apic(void) { }
 static inline void x2apic_setup(void) { }
 static inline int x2apic_enabled(void) { return 0; }
 
 #define x2apic_mode		(0)
 #define	x2apic_supported()	(0)
-#endif
-
-extern void enable_IR_x2apic(void);
-
-extern int get_physical_broadcast(void);
-
-extern int lapic_get_maxlvt(void);
-extern void clear_local_APIC(void);
-extern void disconnect_bsp_APIC(int virt_wire_setup);
-extern void disable_local_APIC(void);
-extern void lapic_shutdown(void);
-extern void sync_Arb_IDs(void);
-extern void init_bsp_APIC(void);
-extern void setup_local_APIC(void);
-extern void init_apic_mappings(void);
-void register_lapic_address(unsigned long address);
-extern void setup_boot_APIC_clock(void);
-extern void setup_secondary_APIC_clock(void);
-extern int APIC_init_uniprocessor(void);
-
-#ifdef CONFIG_X86_64
-static inline int apic_force_enable(unsigned long addr)
-{
-	return -1;
-}
-#else
-extern int apic_force_enable(unsigned long addr);
-#endif
-
-extern int apic_bsp_setup(bool upmode);
-extern void apic_ap_setup(void);
-
-/*
- * On 32bit this is mach-xxx local
- */
-#ifdef CONFIG_X86_64
-extern int apic_is_clustered_box(void);
-#else
-static inline int apic_is_clustered_box(void)
-{
-	return 0;
-}
-#endif
-
-extern int setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask);
-
-#else /* !CONFIG_X86_LOCAL_APIC */
-static inline void lapic_shutdown(void) { }
-#define local_apic_timer_c2_ok		1
-static inline void init_apic_mappings(void) { }
-static inline void disable_local_APIC(void) { }
-# define setup_boot_APIC_clock x86_init_noop
-# define setup_secondary_APIC_clock x86_init_noop
-#endif /* !CONFIG_X86_LOCAL_APIC */
+#endif /* !CONFIG_X86_X2APIC */
 
 #ifdef CONFIG_X86_64
 #define	SET_APIC_ID(x)		(apic->set_apic_id(x))
-- 
1.8.3.1

[tip:x86/apic] x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC

[tip-bot for Paolo Bonzini]

Commit-ID:  e02ae3871355194a61b03a07d96fd71e81d7eff9
Gitweb:     http://git.kernel.org/tip/e02ae3871355194a61b03a07d96fd71e81d7eff9
Author:     Paolo Bonzini <pbonzini@redhat.com>
AuthorDate: Mon, 28 Sep 2015 12:26:31 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 30 Sep 2015 21:17:36 +0200

x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC

Some CONFIG_X86_X2APIC functions, especially x2apic_enabled(), are not
declared if !CONFIG_X86_LOCAL_APIC.  However, the same stubs that work
for !CONFIG_X86_X2APIC are okay even if there is no local APIC support
at all.

Avoid the introduction of #ifdefs by moving the x2apic declarations
completely outside the CONFIG_X86_LOCAL_APIC block.  (Unfortunately,
diff generation messes up the actual change that this patch makes).
There is no semantic change because CONFIG_X86_X2APIC depends on
CONFIG_X86_LOCAL_APIC.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Feng Wu <feng.wu@intel.com>
Link: http://lkml.kernel.org/r/1443435991-35750-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/apic.h | 110 ++++++++++++++++++++++----------------------
 1 file changed, 55 insertions(+), 55 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index ebf6d5e..a30316b 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -115,6 +115,59 @@ static inline bool apic_is_x2apic_enabled(void)
 	return msr & X2APIC_ENABLE;
 }
 
+extern void enable_IR_x2apic(void);
+
+extern int get_physical_broadcast(void);
+
+extern int lapic_get_maxlvt(void);
+extern void clear_local_APIC(void);
+extern void disconnect_bsp_APIC(int virt_wire_setup);
+extern void disable_local_APIC(void);
+extern void lapic_shutdown(void);
+extern void sync_Arb_IDs(void);
+extern void init_bsp_APIC(void);
+extern void setup_local_APIC(void);
+extern void init_apic_mappings(void);
+void register_lapic_address(unsigned long address);
+extern void setup_boot_APIC_clock(void);
+extern void setup_secondary_APIC_clock(void);
+extern int APIC_init_uniprocessor(void);
+
+#ifdef CONFIG_X86_64
+static inline int apic_force_enable(unsigned long addr)
+{
+	return -1;
+}
+#else
+extern int apic_force_enable(unsigned long addr);
+#endif
+
+extern int apic_bsp_setup(bool upmode);
+extern void apic_ap_setup(void);
+
+/*
+ * On 32bit this is mach-xxx local
+ */
+#ifdef CONFIG_X86_64
+extern int apic_is_clustered_box(void);
+#else
+static inline int apic_is_clustered_box(void)
+{
+	return 0;
+}
+#endif
+
+extern int setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask);
+
+#else /* !CONFIG_X86_LOCAL_APIC */
+static inline void lapic_shutdown(void) { }
+#define local_apic_timer_c2_ok		1
+static inline void init_apic_mappings(void) { }
+static inline void disable_local_APIC(void) { }
+# define setup_boot_APIC_clock x86_init_noop
+# define setup_secondary_APIC_clock x86_init_noop
+#endif /* !CONFIG_X86_LOCAL_APIC */
+
 #ifdef CONFIG_X86_X2APIC
 /*
  * Make previous memory operations globally visible before
@@ -186,67 +239,14 @@ static inline int x2apic_enabled(void)
 }
 
 #define x2apic_supported()	(cpu_has_x2apic)
-#else
+#else /* !CONFIG_X86_X2APIC */
 static inline void check_x2apic(void) { }
 static inline void x2apic_setup(void) { }
 static inline int x2apic_enabled(void) { return 0; }
 
 #define x2apic_mode		(0)
 #define	x2apic_supported()	(0)
-#endif
-
-extern void enable_IR_x2apic(void);
-
-extern int get_physical_broadcast(void);
-
-extern int lapic_get_maxlvt(void);
-extern void clear_local_APIC(void);
-extern void disconnect_bsp_APIC(int virt_wire_setup);
-extern void disable_local_APIC(void);
-extern void lapic_shutdown(void);
-extern void sync_Arb_IDs(void);
-extern void init_bsp_APIC(void);
-extern void setup_local_APIC(void);
-extern void init_apic_mappings(void);
-void register_lapic_address(unsigned long address);
-extern void setup_boot_APIC_clock(void);
-extern void setup_secondary_APIC_clock(void);
-extern int APIC_init_uniprocessor(void);
-
-#ifdef CONFIG_X86_64
-static inline int apic_force_enable(unsigned long addr)
-{
-	return -1;
-}
-#else
-extern int apic_force_enable(unsigned long addr);
-#endif
-
-extern int apic_bsp_setup(bool upmode);
-extern void apic_ap_setup(void);
-
-/*
- * On 32bit this is mach-xxx local
- */
-#ifdef CONFIG_X86_64
-extern int apic_is_clustered_box(void);
-#else
-static inline int apic_is_clustered_box(void)
-{
-	return 0;
-}
-#endif
-
-extern int setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask);
-
-#else /* !CONFIG_X86_LOCAL_APIC */
-static inline void lapic_shutdown(void) { }
-#define local_apic_timer_c2_ok		1
-static inline void init_apic_mappings(void) { }
-static inline void disable_local_APIC(void) { }
-# define setup_boot_APIC_clock x86_init_noop
-# define setup_secondary_APIC_clock x86_init_noop
-#endif /* !CONFIG_X86_LOCAL_APIC */
+#endif /* !CONFIG_X86_X2APIC */
 
 #ifdef CONFIG_X86_64
 #define	SET_APIC_ID(x)		(apic->set_apic_id(x))

Re: [tip:x86/apic] x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC

[Thomas Gleixner]

Paolo,

On Wed, 30 Sep 2015, tip-bot for Paolo Bonzini wrote:

> Commit-ID:  e02ae3871355194a61b03a07d96fd71e81d7eff9
> Gitweb:     http://git.kernel.org/tip/e02ae3871355194a61b03a07d96fd71e81d7eff9
> Author:     Paolo Bonzini <pbonzini@redhat.com>
> AuthorDate: Mon, 28 Sep 2015 12:26:31 +0200
> Committer:  Thomas Gleixner <tglx@linutronix.de>
> CommitDate: Wed, 30 Sep 2015 21:17:36 +0200
> 
> x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC

That commit is available for you in a separate branch

  git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/for-kvm

so you can pull that into your tree.

Thanks,

	tglx

Re: [tip:x86/apic] x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC

[Paolo Bonzini]

On 30/09/2015 21:26, Thomas Gleixner wrote:
> Paolo,
> 
> On Wed, 30 Sep 2015, tip-bot for Paolo Bonzini wrote:
> 
>> Commit-ID:  e02ae3871355194a61b03a07d96fd71e81d7eff9
>> Gitweb:     http://git.kernel.org/tip/e02ae3871355194a61b03a07d96fd71e81d7eff9
>> Author:     Paolo Bonzini <pbonzini@redhat.com>
>> AuthorDate: Mon, 28 Sep 2015 12:26:31 +0200
>> Committer:  Thomas Gleixner <tglx@linutronix.de>
>> CommitDate: Wed, 30 Sep 2015 21:17:36 +0200
>>
>> x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC
> 
> That commit is available for you in a separate branch
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/for-kvm
> 
> so you can pull that into your tree.

Thank you very much Thomas.

Paolo