[mirror_ubuntu-jammy-kernel.git] / arch / riscv / kernel / process.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
 *  Chen Liqin <liqin.chen@sunplusct.com>
 *  Lennox Wu <lennox.wu@sunplusct.com>
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2017 SiFive
 */

#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/tick.h>
#include <linux/ptrace.h>
#include <linux/uaccess.h>

#include <asm/unistd.h>
#include <asm/processor.h>
#include <asm/csr.h>
#include <asm/stacktrace.h>
#include <asm/string.h>
#include <asm/switch_to.h>
#include <asm/thread_info.h>

register unsigned long gp_in_global __asm__("gp");

#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif

extern asmlinkage void ret_from_fork(void);
extern asmlinkage void ret_from_kernel_thread(void);

void arch_cpu_idle(void)
{
	wait_for_interrupt();
	raw_local_irq_enable();
}

void __show_regs(struct pt_regs *regs)
{
	show_regs_print_info(KERN_DEFAULT);

	if (!user_mode(regs)) {
		pr_cont("epc : %pS\n", (void *)regs->epc);
		pr_cont(" ra : %pS\n", (void *)regs->ra);
	}

	pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
		regs->epc, regs->ra, regs->sp);
	pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
		regs->gp, regs->tp, regs->t0);
	pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
		regs->t1, regs->t2, regs->s0);
	pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
		regs->s1, regs->a0, regs->a1);
	pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
		regs->a2, regs->a3, regs->a4);
	pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
		regs->a5, regs->a6, regs->a7);
	pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
		regs->s2, regs->s3, regs->s4);
	pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
		regs->s5, regs->s6, regs->s7);
	pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
		regs->s8, regs->s9, regs->s10);
	pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
		regs->s11, regs->t3, regs->t4);
	pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
		regs->t5, regs->t6);

	pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n",
		regs->status, regs->badaddr, regs->cause);
}
void show_regs(struct pt_regs *regs)
{
	__show_regs(regs);
	if (!user_mode(regs))
		dump_backtrace(regs, NULL, KERN_DEFAULT);
}

void start_thread(struct pt_regs *regs, unsigned long pc,
	unsigned long sp)
{
	regs->status = SR_PIE;
	if (has_fpu()) {
		regs->status |= SR_FS_INITIAL;
		/*
		 * Restore the initial value to the FP register
		 * before starting the user program.
		 */
		fstate_restore(current, regs);
	}
	regs->epc = pc;
	regs->sp = sp;
}

void flush_thread(void)
{
#ifdef CONFIG_FPU
	/*
	 * Reset FPU state and context
	 *	frm: round to nearest, ties to even (IEEE default)
	 *	fflags: accrued exceptions cleared
	 */
	fstate_off(current, task_pt_regs(current));
	memset(&current->thread.fstate, 0, sizeof(current->thread.fstate));
#endif
}

int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
	fstate_save(src, task_pt_regs(src));
	*dst = *src;
	return 0;
}

int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
		struct task_struct *p, unsigned long tls)
{
	struct pt_regs *childregs = task_pt_regs(p);

	memset(&p->thread.s, 0, sizeof(p->thread.s));

	/* p->thread holds context to be restored by __switch_to() */
	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
		/* Kernel thread */
		memset(childregs, 0, sizeof(struct pt_regs));
		childregs->gp = gp_in_global;
		/* Supervisor/Machine, irqs on: */
		childregs->status = SR_PP | SR_PIE;

		p->thread.ra = (unsigned long)ret_from_kernel_thread;
		p->thread.s[0] = usp; /* fn */
		p->thread.s[1] = arg;
	} else {
		*childregs = *(current_pt_regs());
		if (usp) /* User fork */
			childregs->sp = usp;
		if (clone_flags & CLONE_SETTLS)
			childregs->tp = tls;
		childregs->a0 = 0; /* Return value of fork() */
		p->thread.ra = (unsigned long)ret_from_fork;
	}
	p->thread.sp = (unsigned long)childregs; /* kernel sp */
	return 0;
}
Commit	Line	Data
588cb88c	1	// SPDX-License-Identifier: GPL-2.0-or-later
7db91e57 PD	2	/*
	3	* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
	4	* Chen Liqin <liqin.chen@sunplusct.com>
	5	* Lennox Wu <lennox.wu@sunplusct.com>
	6	* Copyright (C) 2012 Regents of the University of California
	7	* Copyright (C) 2017 SiFive
7db91e57 PD	8	*/
7db91e57 PD	9
5ed881bc	10	#include <linux/cpu.h>
7db91e57 PD	11	#include <linux/kernel.h>
7db91e57 PD	12	#include <linux/sched.h>
86b276c1	13	#include <linux/sched/debug.h>
7db91e57 PD	14	#include <linux/sched/task_stack.h>
	15	#include <linux/tick.h>
	16	#include <linux/ptrace.h>
5e454b54	17	#include <linux/uaccess.h>
7db91e57 PD	18
7db91e57 PD	19	#include <asm/unistd.h>
7db91e57 PD	20	#include <asm/processor.h>
7db91e57 PD	21	#include <asm/csr.h>
091b9450	22	#include <asm/stacktrace.h>
7db91e57 PD	23	#include <asm/string.h>
7db91e57 PD	24	#include <asm/switch_to.h>
5ed881bc	25	#include <asm/thread_info.h>
7db91e57	26
8356c379	27	register unsigned long gp_in_global __asm__("gp");
52e7c52d	28
fea2fed2	29	#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
f2c9699f GR	30	#include <linux/stackprotector.h>
	31	unsigned long __stack_chk_guard __read_mostly;
	32	EXPORT_SYMBOL(__stack_chk_guard);
	33	#endif
	34
7db91e57 PD	35	extern asmlinkage void ret_from_fork(void);
	36	extern asmlinkage void ret_from_kernel_thread(void);
	37
	38	void arch_cpu_idle(void)
	39	{
	40	wait_for_interrupt();
58c644ba	41	raw_local_irq_enable();
7db91e57 PD	42	}
7db91e57 PD	43
091b9450	44	void __show_regs(struct pt_regs *regs)
7db91e57 PD	45	{
	46	show_regs_print_info(KERN_DEFAULT);
	47
da401e89 KW	48	if (!user_mode(regs)) {
	49	pr_cont("epc : %pS\n", (void *)regs->epc);
	50	pr_cont(" ra : %pS\n", (void *)regs->ra);
	51	}
	52
	53	pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
a4c3733d	54	regs->epc, regs->ra, regs->sp);
7db91e57 PD	55	pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
	56	regs->gp, regs->tp, regs->t0);
	57	pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
	58	regs->t1, regs->t2, regs->s0);
	59	pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
	60	regs->s1, regs->a0, regs->a1);
	61	pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
	62	regs->a2, regs->a3, regs->a4);
	63	pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
	64	regs->a5, regs->a6, regs->a7);
	65	pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
	66	regs->s2, regs->s3, regs->s4);
	67	pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
	68	regs->s5, regs->s6, regs->s7);
	69	pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
	70	regs->s8, regs->s9, regs->s10);
	71	pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
	72	regs->s11, regs->t3, regs->t4);
	73	pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
	74	regs->t5, regs->t6);
	75
a4c3733d CH	76	pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n",
a4c3733d CH	77	regs->status, regs->badaddr, regs->cause);
7db91e57	78	}
091b9450 KW	79	void show_regs(struct pt_regs *regs)
	80	{
	81	__show_regs(regs);
	82	if (!user_mode(regs))
	83	dump_backtrace(regs, NULL, KERN_DEFAULT);
	84	}
7db91e57 PD	85
	86	void start_thread(struct pt_regs *regs, unsigned long pc,
	87	unsigned long sp)
	88	{
a4c3733d	89	regs->status = SR_PIE;
37a7a2a1	90	if (has_fpu()) {
a4c3733d	91	regs->status \|= SR_FS_INITIAL;
8ac71d7e VC	92	/*
	93	* Restore the initial value to the FP register
	94	* before starting the user program.
	95	*/
	96	fstate_restore(current, regs);
	97	}
a4c3733d	98	regs->epc = pc;
7db91e57	99	regs->sp = sp;
7db91e57 PD	100	}
	101
	102	void flush_thread(void)
	103	{
9671f706	104	#ifdef CONFIG_FPU
7db91e57	105	/*
8ac71d7e	106	* Reset FPU state and context
7db91e57 PD	107	* frm: round to nearest, ties to even (IEEE default)
	108	* fflags: accrued exceptions cleared
	109	*/
8ac71d7e	110	fstate_off(current, task_pt_regs(current));
7db91e57	111	memset(&current->thread.fstate, 0, sizeof(current->thread.fstate));
9671f706	112	#endif
7db91e57 PD	113	}
	114
	115	int arch_dup_task_struct(struct task_struct dst, struct task_struct src)
	116	{
	117	fstate_save(src, task_pt_regs(src));
	118	dst = src;
	119	return 0;
	120	}
	121
714acdbd CB	122	int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
714acdbd CB	123	struct task_struct *p, unsigned long tls)
7db91e57 PD	124	{
	125	struct pt_regs *childregs = task_pt_regs(p);
	126
092482e4 JZ	127	memset(&p->thread.s, 0, sizeof(p->thread.s));
092482e4 JZ	128
7db91e57	129	/* p->thread holds context to be restored by __switch_to() */
4727dc20	130	if (unlikely(p->flags & (PF_KTHREAD \| PF_IO_WORKER))) {
7db91e57	131	/* Kernel thread */
7db91e57	132	memset(childregs, 0, sizeof(struct pt_regs));
52e7c52d	133	childregs->gp = gp_in_global;
a4c3733d CH	134	/* Supervisor/Machine, irqs on: */
a4c3733d CH	135	childregs->status = SR_PP \| SR_PIE;
7db91e57 PD	136
	137	p->thread.ra = (unsigned long)ret_from_kernel_thread;
	138	p->thread.s[0] = usp; /* fn */
	139	p->thread.s[1] = arg;
	140	} else {
	141	childregs = (current_pt_regs());
	142	if (usp) /* User fork */
	143	childregs->sp = usp;
	144	if (clone_flags & CLONE_SETTLS)
20bda4ed	145	childregs->tp = tls;
7db91e57 PD	146	childregs->a0 = 0; /* Return value of fork() */
	147	p->thread.ra = (unsigned long)ret_from_fork;
	148	}
	149	p->thread.sp = (unsigned long)childregs; /* kernel sp */
	150	return 0;
	151	}