Introduce x86_64 %rip-relative addressing to PER_CPU_VAR macro. Instruction with %rip-relative address operand is one byte shorter than its absolute address counterpart and is also compatible with position independent executable (-fpie) build.
Cc: Thomas Gleixner <t...@linutronix.de> Cc: Ingo Molnar <mi...@redhat.com> Cc: Borislav Petkov <b...@alien8.de> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Uros Bizjak <ubiz...@gmail.com> --- arch/x86/include/asm/percpu.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 83e6a4bcea38..c53c5a7f8e78 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -4,19 +4,21 @@ #ifdef CONFIG_X86_64 #define __percpu_seg gs +#define __percpu_rel (%rip) #else #define __percpu_seg fs +#define __percpu_rel #endif #ifdef __ASSEMBLY__ #ifdef CONFIG_SMP #define PER_CPU_ARG(arg) %__percpu_seg:arg -#define PER_CPU_VAR(var) %__percpu_seg:var +#define PER_CPU_VAR(var) %__percpu_seg:(var)##__percpu_rel #else /* ! SMP */ #define PER_CPU_ARG(arg) arg -#define PER_CPU_VAR(var) var -#endif /* SMP */ +#define PER_CPU_VAR(var) (var)##__percpu_rel +#endif /* SMP */ #ifdef CONFIG_X86_64_SMP #define INIT_PER_CPU_VAR(var) init_per_cpu__##var -- 2.41.0
