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@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a2bf4f07fbc30fb32f9f7f3f8f94ad3580823847.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index 678637a..59d34c5 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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);