// SPDX-License-Identifier: GPL-2.0-only/* * arch/arm/kernel/thumbee.c * * Copyright (C) 2008 ARM Limited */ #include <linux/kernel.h>#include <linux/init.h> #include <asm/cputype.h>#include <asm/system_info.h>#include <asm/thread_notify.h> /* * Access to the ThumbEE Handler Base register */static inline unsigned long teehbr_read(void){	unsigned long v;	asm("mrc	p14, 6, %0, c1, c0, 0\n" : "=r" (v));	return v;} static inline void teehbr_write(unsigned long v){	asm("mcr	p14, 6, %0, c1, c0, 0\n" : : "r" (v));} static int thumbee_notifier(struct notifier_block *self, unsigned long cmd, void *t){	struct thread_info *thread = t; 	switch (cmd) {	case THREAD_NOTIFY_FLUSH:		teehbr_write(0);		break;	case THREAD_NOTIFY_SWITCH:		current_thread_info()->thumbee_state = teehbr_read();		teehbr_write(thread->thumbee_state);		break;	} 	return NOTIFY_DONE;} static struct notifier_block thumbee_notifier_block = {	.notifier_call	= thumbee_notifier,}; static int __init thumbee_init(void){	unsigned long pfr0;	unsigned int cpu_arch = cpu_architecture(); 	if (cpu_arch < CPU_ARCH_ARMv7)		return 0; 	pfr0 = read_cpuid_ext(CPUID_EXT_PFR0);	if ((pfr0 & 0x0000f000) != 0x00001000)		return 0; 	pr_info("ThumbEE CPU extension supported.\n");	elf_hwcap |= HWCAP_THUMBEE;	thread_register_notifier(&thumbee_notifier_block); 	return 0;} late_initcall(thumbee_init);