18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0-only */ 28c2ecf20Sopenharmony_ci/* 38c2ecf20Sopenharmony_ci * Copyright 2012 Calxeda, Inc. 48c2ecf20Sopenharmony_ci */ 58c2ecf20Sopenharmony_ci#ifndef _ASM_ARM_PERCPU_H_ 68c2ecf20Sopenharmony_ci#define _ASM_ARM_PERCPU_H_ 78c2ecf20Sopenharmony_ci 88c2ecf20Sopenharmony_ciregister unsigned long current_stack_pointer asm ("sp"); 98c2ecf20Sopenharmony_ci 108c2ecf20Sopenharmony_ci/* 118c2ecf20Sopenharmony_ci * Same as asm-generic/percpu.h, except that we store the per cpu offset 128c2ecf20Sopenharmony_ci * in the TPIDRPRW. TPIDRPRW only exists on V6K and V7 138c2ecf20Sopenharmony_ci */ 148c2ecf20Sopenharmony_ci#if defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6) 158c2ecf20Sopenharmony_cistatic inline void set_my_cpu_offset(unsigned long off) 168c2ecf20Sopenharmony_ci{ 178c2ecf20Sopenharmony_ci /* Set TPIDRPRW */ 188c2ecf20Sopenharmony_ci asm volatile("mcr p15, 0, %0, c13, c0, 4" : : "r" (off) : "memory"); 198c2ecf20Sopenharmony_ci} 208c2ecf20Sopenharmony_ci 218c2ecf20Sopenharmony_cistatic inline unsigned long __my_cpu_offset(void) 228c2ecf20Sopenharmony_ci{ 238c2ecf20Sopenharmony_ci unsigned long off; 248c2ecf20Sopenharmony_ci 258c2ecf20Sopenharmony_ci /* 268c2ecf20Sopenharmony_ci * Read TPIDRPRW. 278c2ecf20Sopenharmony_ci * We want to allow caching the value, so avoid using volatile and 288c2ecf20Sopenharmony_ci * instead use a fake stack read to hazard against barrier(). 298c2ecf20Sopenharmony_ci */ 308c2ecf20Sopenharmony_ci asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) 318c2ecf20Sopenharmony_ci : "Q" (*(const unsigned long *)current_stack_pointer)); 328c2ecf20Sopenharmony_ci 338c2ecf20Sopenharmony_ci return off; 348c2ecf20Sopenharmony_ci} 358c2ecf20Sopenharmony_ci#define __my_cpu_offset __my_cpu_offset() 368c2ecf20Sopenharmony_ci#else 378c2ecf20Sopenharmony_ci#define set_my_cpu_offset(x) do {} while(0) 388c2ecf20Sopenharmony_ci 398c2ecf20Sopenharmony_ci#endif /* CONFIG_SMP */ 408c2ecf20Sopenharmony_ci 418c2ecf20Sopenharmony_ci#include <asm-generic/percpu.h> 428c2ecf20Sopenharmony_ci 438c2ecf20Sopenharmony_ci#endif /* _ASM_ARM_PERCPU_H_ */ 44