// SPDX-License-Identifier: GPL-2.0/* * arch/sh/kernel/process.c * * This file handles the architecture-dependent parts of process handling.. * *  Copyright (C) 1995  Linus Torvalds * *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima *		     Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC *		     Copyright (C) 2002 - 2008  Paul Mundt */#include <linux/module.h>#include <linux/mm.h>#include <linux/sched/debug.h>#include <linux/sched/task.h>#include <linux/sched/task_stack.h>#include <linux/slab.h>#include <linux/elfcore.h>#include <linux/fs.h>#include <linux/ftrace.h>#include <linux/hw_breakpoint.h>#include <linux/prefetch.h>#include <linux/stackprotector.h>#include <linux/uaccess.h>#include <asm/mmu_context.h>#include <asm/fpu.h>#include <asm/syscalls.h>#include <asm/switch_to.h> void show_regs(struct pt_regs * regs){	pr_info("\n");	show_regs_print_info(KERN_DEFAULT); 	pr_info("PC is at %pS\n", (void *)instruction_pointer(regs));	pr_info("PR is at %pS\n", (void *)regs->pr); 	pr_info("PC  : %08lx SP  : %08lx SR  : %08lx ", regs->pc,		regs->regs[15], regs->sr);#ifdef CONFIG_MMU	pr_cont("TEA : %08x\n", __raw_readl(MMU_TEA));#else	pr_cont("\n");#endif 	pr_info("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",		regs->regs[0], regs->regs[1], regs->regs[2], regs->regs[3]);	pr_info("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",		regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]);	pr_info("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",		regs->regs[8], regs->regs[9], regs->regs[10], regs->regs[11]);	pr_info("R12 : %08lx R13 : %08lx R14 : %08lx\n",		regs->regs[12], regs->regs[13], regs->regs[14]);	pr_info("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",		regs->mach, regs->macl, regs->gbr, regs->pr); 	show_trace(NULL, (unsigned long *)regs->regs[15], regs, KERN_DEFAULT);	show_code(regs);} void start_thread(struct pt_regs *regs, unsigned long new_pc,		  unsigned long new_sp){	regs->pr = 0;	regs->sr = SR_FD;	regs->pc = new_pc;	regs->regs[15] = new_sp; 	free_thread_xstate(current);}EXPORT_SYMBOL(start_thread); void flush_thread(void){	struct task_struct *tsk = current; 	flush_ptrace_hw_breakpoint(tsk); #if defined(CONFIG_SH_FPU)	/* Forget lazy FPU state */	clear_fpu(tsk, task_pt_regs(tsk));	clear_used_math();#endif} void release_thread(struct task_struct *dead_task){	/* do nothing */} asmlinkage void ret_from_fork(void);asmlinkage void ret_from_kernel_thread(void); int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,		struct task_struct *p, unsigned long tls){	struct thread_info *ti = task_thread_info(p);	struct pt_regs *childregs; #if defined(CONFIG_SH_DSP)	struct task_struct *tsk = current; 	if (is_dsp_enabled(tsk)) {		/* We can use the __save_dsp or just copy the struct:		 * __save_dsp(p);		 * p->thread.dsp_status.status |= SR_DSP		 */		p->thread.dsp_status = tsk->thread.dsp_status;	}#endif 	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps)); 	childregs = task_pt_regs(p);	p->thread.sp = (unsigned long) childregs;	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {		memset(childregs, 0, sizeof(struct pt_regs));		p->thread.pc = (unsigned long) ret_from_kernel_thread;		childregs->regs[4] = arg;		childregs->regs[5] = usp;		childregs->sr = SR_MD;#if defined(CONFIG_SH_FPU)		childregs->sr |= SR_FD;#endif		ti->addr_limit = KERNEL_DS;		ti->status &= ~TS_USEDFPU;		p->thread.fpu_counter = 0;		return 0;	}	*childregs = *current_pt_regs(); 	if (usp)		childregs->regs[15] = usp;	ti->addr_limit = USER_DS; 	if (clone_flags & CLONE_SETTLS)		childregs->gbr = tls; 	childregs->regs[0] = 0; /* Set return value for child */	p->thread.pc = (unsigned long) ret_from_fork;	return 0;} /* *	switch_to(x,y) should switch tasks from x to y. * */__notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next){	struct thread_struct *next_t = &next->thread; #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)	__stack_chk_guard = next->stack_canary;#endif 	unlazy_fpu(prev, task_pt_regs(prev)); 	/* we're going to use this soon, after a few expensive things */	if (next->thread.fpu_counter > 5)		prefetch(next_t->xstate); #ifdef CONFIG_MMU	/*	 * Restore the kernel mode register	 *	k7 (r7_bank1)	 */	asm volatile("ldc	%0, r7_bank"		     : /* no output */		     : "r" (task_thread_info(next)));#endif 	/*	 * If the task has used fpu the last 5 timeslices, just do a full	 * restore of the math state immediately to avoid the trap; the	 * chances of needing FPU soon are obviously high now	 */	if (next->thread.fpu_counter > 5)		__fpu_state_restore(); 	return prev;} unsigned long get_wchan(struct task_struct *p){	unsigned long pc; 	if (!p || p == current || p->state == TASK_RUNNING)		return 0; 	/*	 * The same comment as on the Alpha applies here, too ...	 */	pc = thread_saved_pc(p); #ifdef CONFIG_FRAME_POINTER	if (in_sched_functions(pc)) {		unsigned long schedule_frame = (unsigned long)p->thread.sp;		return ((unsigned long *)schedule_frame)[21];	}#endif 	return pc;}