[tip:x86/mm] x86/smp: Remove stack_smp_processor_id()

[tip-bot for Andy Lutomirski]

Commit-ID:  fb59831b496a5bb7d0a06c7e702d88d1757edfca
Gitweb:     http://git.kernel.org/tip/fb59831b496a5bb7d0a06c7e702d88d1757edfca
Author:     Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Thu, 14 Jul 2016 13:22:58 -0700
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 15 Jul 2016 10:26:30 +0200

x86/smp: Remove stack_smp_processor_id()

It serves no purpose -- raw_smp_processor_id() works fine.  This
change will be needed to move thread_info off the stack.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/a2bf4f07fbc30fb32f9f7f3f8f94ad3580823847.1468527351.git.luto@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/include/asm/cpu.h   | 1 -
 arch/x86/include/asm/smp.h   | 6 ------
 arch/x86/kernel/cpu/common.c | 2 +-
 3 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 678637a..59d34c5 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -17,7 +17,6 @@ static inline void prefill_possible_map(void) {}
 
 #define cpu_physical_id(cpu)			boot_cpu_physical_apicid
 #define safe_smp_processor_id()			0
-#define stack_smp_processor_id()		0
 
 #endif /* CONFIG_SMP */
 
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 66b0573..0576b61 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -172,12 +172,6 @@ extern int safe_smp_processor_id(void);
 #elif defined(CONFIG_X86_64_SMP)
 #define raw_smp_processor_id() (this_cpu_read(cpu_number))
 
-#define stack_smp_processor_id()					\
-({								\
-	struct thread_info *ti;						\
-	__asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (CURRENT_MASK));	\
-	ti->cpu;							\
-})
 #define safe_smp_processor_id()		smp_processor_id()
 
 #endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 0fe6953..d22a7b9 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1452,7 +1452,7 @@ void cpu_init(void)
 	struct task_struct *me;
 	struct tss_struct *t;
 	unsigned long v;
-	int cpu = stack_smp_processor_id();
+	int cpu = raw_smp_processor_id();
 	int i;
 
 	wait_for_master_cpu(cpu);