/* * Copyright 2010 Tilera Corporation. All Rights Reserved. * *   This program is free software; you can redistribute it and/or *   modify it under the terms of the GNU General Public License *   as published by the Free Software Foundation, version 2. * *   This program is distributed in the hope that it will be useful, but *   WITHOUT ANY WARRANTY; without even the implied warranty of *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or *   NON INFRINGEMENT.  See the GNU General Public License for *   more details. */ #ifndef _ASM_TILE_PERCPU_H#define _ASM_TILE_PERCPU_H register unsigned long my_cpu_offset_reg asm("tp"); #ifdef CONFIG_PREEMPT/* * For full preemption, we can't just use the register variable * directly, since we need barrier() to hazard against it, causing the * compiler to reload anything computed from a previous "tp" value. * But we also don't want to use volatile asm, since we'd like the * compiler to be able to cache the value across multiple percpu reads. * So we use a fake stack read as a hazard against barrier(). * The 'U' constraint is like 'm' but disallows postincrement. */static inline unsigned long __my_cpu_offset(void){	unsigned long tp;	register unsigned long *sp asm("sp");	asm("move %0, tp" : "=r" (tp) : "U" (*sp));	return tp;}#define __my_cpu_offset __my_cpu_offset()#else/* * We don't need to hazard against barrier() since "tp" doesn't ever * change with PREEMPT_NONE, and with PREEMPT_VOLUNTARY it only * changes at function call points, at which we are already re-reading * the value of "tp" due to "my_cpu_offset_reg" being a global variable. */#define __my_cpu_offset my_cpu_offset_reg#endif #define set_my_cpu_offset(tp) (my_cpu_offset_reg = (tp)) #include <asm-generic/percpu.h> #endif /* _ASM_TILE_PERCPU_H */