locking/core: Provide common cpu_relax_yield() definition

No need to duplicate the same define everywhere. Since
the only user is stop-machine and the only provider is
s390, we can use a default implementation of cpu_relax_yield()
in sched.h.

Suggested-by: Russell King <[e-mail]>
Signed-off-by: Christian Borntraeger <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Acked-by: Russell King <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Martin Schwidefsky <[e-mail]>
Cc: Nicholas Piggin <[e-mail]>
Cc: Noam Camus <[e-mail]>
Cc: Paul E. McKenney <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: linux-s390 <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/alpha/include/asm/processor.h

···
   ((tsk) == current ? rdusp() : task_thread_info(tsk)->pcb.usp)
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 #define ARCH_HAS_PREFETCH
 #define ARCH_HAS_PREFETCHW

arch/arc/include/asm/processor.h

···
 #ifndef CONFIG_EZNPS_MTM_EXT
 
 #define cpu_relax()		barrier()
-#define cpu_relax_yield()	cpu_relax()
 
 #else
 
 #define cpu_relax()     \
 	__asm__ __volatile__ (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
-
-#define cpu_relax_yield()	cpu_relax()
 
 #endif
 

arch/arm/include/asm/processor.h

···
 #define cpu_relax()			barrier()
 #endif
 
-#define cpu_relax_yield()  	              cpu_relax()
-
 #define task_pt_regs(p) \
 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
 

arch/arm64/include/asm/processor.h

···
 	asm volatile("yield" ::: "memory");
 }
 
-#define cpu_relax_yield()                     cpu_relax()
-
 /* Thread switching */
 extern struct task_struct *cpu_switch_to(struct task_struct *prev,
 					 struct task_struct *next);

arch/avr32/include/asm/processor.h

···
 #define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 3))
 
 #define cpu_relax()		barrier()
-#define cpu_relax_yield()	cpu_relax()
 #define cpu_sync_pipeline()	asm volatile("sub pc, -2" : : : "memory")
 
 struct cpu_context {

arch/blackfin/include/asm/processor.h

···
 #define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)
 
 #define cpu_relax()    	smp_mb()
-#define cpu_relax_yield()      cpu_relax()
 
 /* Get the Silicon Revision of the chip */
 static inline uint32_t __pure bfin_revid(void)

arch/c6x/include/asm/processor.h

···
 #define KSTK_ESP(task)	(task_pt_regs(task)->sp)
 
 #define cpu_relax()		do { } while (0)
-#define cpu_relax_yield()             cpu_relax()
 
 extern const struct seq_operations cpuinfo_op;
 

arch/cris/include/asm/processor.h

···
 #define init_stack      (init_thread_union.stack)
 
 #define cpu_relax()     barrier()
-#define cpu_relax_yield() cpu_relax()
 
 void default_idle(void);
 

arch/frv/include/asm/processor.h

···
 #define	KSTK_ESP(tsk)	((tsk)->thread.frame0->sp)
 
 #define cpu_relax() barrier()
-#define cpu_relax_yield() cpu_relax()
 
 /* data cache prefetch */
 #define ARCH_HAS_PREFETCH

arch/h8300/include/asm/processor.h

···
 #define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)
 
 #define cpu_relax()    barrier()
-#define cpu_relax_yield() cpu_relax()
 
 #define HARD_RESET_NOW() ({		\
 	local_irq_disable();		\

arch/hexagon/include/asm/processor.h

···
 }
 
 #define cpu_relax() __vmyield()
-#define cpu_relax_yield() cpu_relax()
 
 /*
  * Decides where the kernel will search for a free chunk of vm space during

arch/ia64/include/asm/processor.h

···
 }
 
 #define cpu_relax()	ia64_hint(ia64_hint_pause)
-#define cpu_relax_yield() cpu_relax()
 
 static inline int
 ia64_get_irr(unsigned int vector)

arch/m32r/include/asm/processor.h

···
 #define KSTK_ESP(tsk)  ((tsk)->thread.sp)
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 #endif /* _ASM_M32R_PROCESSOR_H */

arch/m68k/include/asm/processor.h

···
 #define task_pt_regs(tsk)	((struct pt_regs *) ((tsk)->thread.esp0))
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 #endif

arch/metag/include/asm/processor.h

···
 #define user_stack_pointer(regs)        ((regs)->ctx.AX[0].U0)
 
 #define cpu_relax()     barrier()
-#define cpu_relax_yield() cpu_relax()
 
 extern void setup_priv(void);
 

arch/microblaze/include/asm/processor.h

···
 extern const struct seq_operations cpuinfo_op;
 
 # define cpu_relax()		barrier()
-# define cpu_relax_yield() cpu_relax()
 
 #define task_pt_regs(tsk) \
 		(((struct pt_regs *)(THREAD_SIZE + task_stack_page(tsk))) - 1)

arch/mips/include/asm/processor.h

···
 #define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status)
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 /*
  * Return_address is a replacement for __builtin_return_address(count)

arch/mn10300/include/asm/processor.h

···
 extern void dodgy_tsc(void);
 
 #define cpu_relax() barrier()
-#define cpu_relax_yield() cpu_relax()
 
 /*
  * User space process size: 1.75GB (default).

arch/nios2/include/asm/processor.h

···
 #define KSTK_ESP(tsk)	((tsk)->thread.kregs->sp)
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 #endif /* __ASSEMBLY__ */
 

arch/openrisc/include/asm/processor.h

···
 #define init_stack      (init_thread_union.stack)
 
 #define cpu_relax()     barrier()
-#define cpu_relax_yield() cpu_relax()
 
 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_OPENRISC_PROCESSOR_H */

arch/parisc/include/asm/processor.h

···
 #define KSTK_ESP(tsk)	((tsk)->thread.regs.gr[30])
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 /*
  * parisc_requires_coherency() is used to identify the combined VIPT/PIPT

arch/powerpc/include/asm/processor.h

···
 #define cpu_relax()	barrier()
 #endif
 
-#define cpu_relax_yield() cpu_relax()
-
 /* Check that a certain kernel stack pointer is valid in task_struct p */
 int validate_sp(unsigned long sp, struct task_struct *p,
                        unsigned long nbytes);

arch/s390/include/asm/processor.h

···
 /*
  * Give up the time slice of the virtual PU.
  */
+#define cpu_relax_yield cpu_relax_yield
 void cpu_relax_yield(void);
 
 #define cpu_relax() barrier()

arch/score/include/asm/processor.h

···
 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
 
 #define cpu_relax()		barrier()
-#define cpu_relax_yield()	cpu_relax()
 #define release_thread(thread)	do {} while (0)
 
 /*

arch/sh/include/asm/processor.h

···
 
 #define cpu_sleep()	__asm__ __volatile__ ("sleep" : : : "memory")
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 void default_idle(void);
 void stop_this_cpu(void *);

arch/sparc/include/asm/processor_32.h

···
 int do_mathemu(struct pt_regs *regs, struct task_struct *fpt);
 
 #define cpu_relax()	barrier()
-#define cpu_relax_yield() cpu_relax()
 
 extern void (*sparc_idle)(void);
 

arch/sparc/include/asm/processor_64.h

···
 				     "nop\n\t"				\
 				     ".previous"			\
 				     ::: "memory")
-#define cpu_relax_yield() cpu_relax()
 
 /* Prefetch support.  This is tuned for UltraSPARC-III and later.
  * UltraSPARC-I will treat these as nops, and UltraSPARC-II has

arch/tile/include/asm/processor.h

···
 	barrier();
 }
 
-#define cpu_relax_yield() cpu_relax()
-
 /* Info on this processor (see fs/proc/cpuinfo.c) */
 struct seq_operations;
 extern const struct seq_operations cpuinfo_op;

arch/unicore32/include/asm/processor.h

···
 unsigned long get_wchan(struct task_struct *p);
 
 #define cpu_relax()			barrier()
-#define cpu_relax_yield()		cpu_relax()
 
 #define task_pt_regs(p) \
 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)

arch/x86/include/asm/processor.h

···
 	rep_nop();
 }
 
-#define cpu_relax_yield() cpu_relax()
-
 /* Stop speculative execution and prefetching of modified code. */
 static inline void sync_core(void)
 {

arch/x86/um/asm/processor.h

···
 }
 
 #define cpu_relax()		rep_nop()
-#define cpu_relax_yield()	cpu_relax()
 
 #define task_pt_regs(t) (&(t)->thread.regs)
 

arch/xtensa/include/asm/processor.h

···
 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->areg[1])
 
 #define cpu_relax()  barrier()
-#define cpu_relax_yield() cpu_relax()
 
 /* Special register access. */
 

include/linux/sched.h

···
 static inline void calc_load_exit_idle(void) { }
 #endif /* CONFIG_NO_HZ_COMMON */
 
+#ifndef cpu_relax_yield
+#define cpu_relax_yield() cpu_relax()
+#endif
+
 /*
  * Do not use outside of architecture code which knows its limitations.
  *