[linux-block.git] / arch / loongarch / kernel / process.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Author: Huacai Chen <chenhuacai@loongson.cn>
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 *
 * Derived from MIPS:
 * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
 * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2004 Thiemo Seufer
 * Copyright (C) 2013  Imagination Technologies Ltd.
 */
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/export.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/personality.h>
#include <linux/sys.h>
#include <linux/completion.h>
#include <linux/kallsyms.h>
#include <linux/random.h>
#include <linux/prctl.h>
#include <linux/nmi.h>

#include <asm/asm.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
#include <asm/elf.h>
#include <asm/fpu.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/irq_regs.h>
#include <asm/loongarch.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/reg.h>
#include <asm/unwind.h>
#include <asm/vdso.h>

#ifdef CONFIG_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif

/*
 * Idle related variables and functions
 */

unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
EXPORT_SYMBOL(boot_option_idle_override);

#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
	play_dead();
}
#endif

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

void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
{
	unsigned long crmd;
	unsigned long prmd;
	unsigned long euen;

	/* New thread loses kernel privileges. */
	crmd = regs->csr_crmd & ~(PLV_MASK);
	crmd |= PLV_USER;
	regs->csr_crmd = crmd;

	prmd = regs->csr_prmd & ~(PLV_MASK);
	prmd |= PLV_USER;
	regs->csr_prmd = prmd;

	euen = regs->csr_euen & ~(CSR_EUEN_FPEN);
	regs->csr_euen = euen;
	lose_fpu(0);

	clear_thread_flag(TIF_LSX_CTX_LIVE);
	clear_thread_flag(TIF_LASX_CTX_LIVE);
	clear_used_math();
	regs->csr_era = pc;
	regs->regs[3] = sp;
}

void exit_thread(struct task_struct *tsk)
{
}

int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
	/*
	 * Save any process state which is live in hardware registers to the
	 * parent context prior to duplication. This prevents the new child
	 * state becoming stale if the parent is preempted before copy_thread()
	 * gets a chance to save the parent's live hardware registers to the
	 * child context.
	 */
	preempt_disable();

	if (is_fpu_owner())
		save_fp(current);

	preempt_enable();

	if (used_math())
		memcpy(dst, src, sizeof(struct task_struct));
	else
		memcpy(dst, src, offsetof(struct task_struct, thread.fpu.fpr));

	return 0;
}

/*
 * Copy architecture-specific thread state
 */
int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
{
	unsigned long childksp;
	unsigned long tls = args->tls;
	unsigned long usp = args->stack;
	unsigned long clone_flags = args->flags;
	struct pt_regs *childregs, *regs = current_pt_regs();

	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE;

	/* set up new TSS. */
	childregs = (struct pt_regs *) childksp - 1;
	/*  Put the stack after the struct pt_regs.  */
	childksp = (unsigned long) childregs;
	p->thread.sched_cfa = 0;
	p->thread.csr_euen = 0;
	p->thread.csr_crmd = csr_read32(LOONGARCH_CSR_CRMD);
	p->thread.csr_prmd = csr_read32(LOONGARCH_CSR_PRMD);
	p->thread.csr_ecfg = csr_read32(LOONGARCH_CSR_ECFG);
	if (unlikely(args->fn)) {
		/* kernel thread */
		p->thread.reg03 = childksp;
		p->thread.reg23 = (unsigned long)args->fn;
		p->thread.reg24 = (unsigned long)args->fn_arg;
		p->thread.reg01 = (unsigned long)ret_from_kernel_thread;
		p->thread.sched_ra = (unsigned long)ret_from_kernel_thread;
		memset(childregs, 0, sizeof(struct pt_regs));
		childregs->csr_euen = p->thread.csr_euen;
		childregs->csr_crmd = p->thread.csr_crmd;
		childregs->csr_prmd = p->thread.csr_prmd;
		childregs->csr_ecfg = p->thread.csr_ecfg;
		goto out;
	}

	/* user thread */
	*childregs = *regs;
	childregs->regs[4] = 0; /* Child gets zero as return value */
	if (usp)
		childregs->regs[3] = usp;

	p->thread.reg03 = (unsigned long) childregs;
	p->thread.reg01 = (unsigned long) ret_from_fork;
	p->thread.sched_ra = (unsigned long) ret_from_fork;

	/*
	 * New tasks lose permission to use the fpu. This accelerates context
	 * switching for most programs since they don't use the fpu.
	 */
	childregs->csr_euen = 0;

	if (clone_flags & CLONE_SETTLS)
		childregs->regs[2] = tls;

out:
	clear_tsk_thread_flag(p, TIF_USEDFPU);
	clear_tsk_thread_flag(p, TIF_USEDSIMD);
	clear_tsk_thread_flag(p, TIF_LSX_CTX_LIVE);
	clear_tsk_thread_flag(p, TIF_LASX_CTX_LIVE);

	return 0;
}

unsigned long __get_wchan(struct task_struct *task)
{
	unsigned long pc = 0;
	struct unwind_state state;

	if (!try_get_task_stack(task))
		return 0;

	for (unwind_start(&state, task, NULL);
	     !unwind_done(&state); unwind_next_frame(&state)) {
		pc = unwind_get_return_address(&state);
		if (!pc)
			break;
		if (in_sched_functions(pc))
			continue;
		break;
	}

	put_task_stack(task);

	return pc;
}

bool in_irq_stack(unsigned long stack, struct stack_info *info)
{
	unsigned long nextsp;
	unsigned long begin = (unsigned long)this_cpu_read(irq_stack);
	unsigned long end = begin + IRQ_STACK_START;

	if (stack < begin || stack >= end)
		return false;

	nextsp = *(unsigned long *)end;
	if (nextsp & (SZREG - 1))
		return false;

	info->begin = begin;
	info->end = end;
	info->next_sp = nextsp;
	info->type = STACK_TYPE_IRQ;

	return true;
}

bool in_task_stack(unsigned long stack, struct task_struct *task,
			struct stack_info *info)
{
	unsigned long begin = (unsigned long)task_stack_page(task);
	unsigned long end = begin + THREAD_SIZE;

	if (stack < begin || stack >= end)
		return false;

	info->begin = begin;
	info->end = end;
	info->next_sp = 0;
	info->type = STACK_TYPE_TASK;

	return true;
}

int get_stack_info(unsigned long stack, struct task_struct *task,
		   struct stack_info *info)
{
	task = task ? : current;

	if (!stack || stack & (SZREG - 1))
		goto unknown;

	if (in_task_stack(stack, task, info))
		return 0;

	if (task != current)
		goto unknown;

	if (in_irq_stack(stack, info))
		return 0;

unknown:
	info->type = STACK_TYPE_UNKNOWN;
	return -EINVAL;
}

unsigned long stack_top(void)
{
	unsigned long top = TASK_SIZE & PAGE_MASK;

	/* Space for the VDSO & data page */
	top -= PAGE_ALIGN(current->thread.vdso->size);
	top -= PAGE_SIZE;

	/* Space to randomize the VDSO base */
	if (current->flags & PF_RANDOMIZE)
		top -= VDSO_RANDOMIZE_SIZE;

	return top;
}

/*
 * Don't forget that the stack pointer must be aligned on a 8 bytes
 * boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
 */
unsigned long arch_align_stack(unsigned long sp)
{
	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
		sp -= get_random_u32_below(PAGE_SIZE);

	return sp & STACK_ALIGN;
}

static DEFINE_PER_CPU(call_single_data_t, backtrace_csd);
static struct cpumask backtrace_csd_busy;

static void handle_backtrace(void *info)
{
	nmi_cpu_backtrace(get_irq_regs());
	cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy);
}

static void raise_backtrace(cpumask_t *mask)
{
	call_single_data_t *csd;
	int cpu;

	for_each_cpu(cpu, mask) {
		/*
		 * If we previously sent an IPI to the target CPU & it hasn't
		 * cleared its bit in the busy cpumask then it didn't handle
		 * our previous IPI & it's not safe for us to reuse the
		 * call_single_data_t.
		 */
		if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) {
			pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n",
				cpu);
			continue;
		}

		csd = &per_cpu(backtrace_csd, cpu);
		csd->func = handle_backtrace;
		smp_call_function_single_async(cpu, csd);
	}
}

void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
{
	nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace);
}

#ifdef CONFIG_64BIT
void loongarch_dump_regs64(u64 *uregs, const struct pt_regs *regs)
{
	unsigned int i;

	for (i = LOONGARCH_EF_R1; i <= LOONGARCH_EF_R31; i++) {
		uregs[i] = regs->regs[i - LOONGARCH_EF_R0];
	}

	uregs[LOONGARCH_EF_ORIG_A0] = regs->orig_a0;
	uregs[LOONGARCH_EF_CSR_ERA] = regs->csr_era;
	uregs[LOONGARCH_EF_CSR_BADV] = regs->csr_badvaddr;
	uregs[LOONGARCH_EF_CSR_CRMD] = regs->csr_crmd;
	uregs[LOONGARCH_EF_CSR_PRMD] = regs->csr_prmd;
	uregs[LOONGARCH_EF_CSR_EUEN] = regs->csr_euen;
	uregs[LOONGARCH_EF_CSR_ECFG] = regs->csr_ecfg;
	uregs[LOONGARCH_EF_CSR_ESTAT] = regs->csr_estat;
}
#endif /* CONFIG_64BIT */
Commit	Line	Data
803b0fc5 HC	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Author: Huacai Chen <chenhuacai@loongson.cn>
	4	* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
	5	*
	6	* Derived from MIPS:
	7	* Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
	8	* Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
	9	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
	10	* Copyright (C) 2004 Thiemo Seufer
	11	* Copyright (C) 2013 Imagination Technologies Ltd.
	12	*/
	13	#include <linux/cpu.h>
	14	#include <linux/init.h>
	15	#include <linux/kernel.h>
	16	#include <linux/errno.h>
	17	#include <linux/sched.h>
	18	#include <linux/sched/debug.h>
	19	#include <linux/sched/task.h>
	20	#include <linux/sched/task_stack.h>
	21	#include <linux/mm.h>
	22	#include <linux/stddef.h>
	23	#include <linux/unistd.h>
	24	#include <linux/export.h>
	25	#include <linux/ptrace.h>
	26	#include <linux/mman.h>
	27	#include <linux/personality.h>
	28	#include <linux/sys.h>
	29	#include <linux/completion.h>
	30	#include <linux/kallsyms.h>
	31	#include <linux/random.h>
	32	#include <linux/prctl.h>
	33	#include <linux/nmi.h>
	34
	35	#include <asm/asm.h>
	36	#include <asm/bootinfo.h>
	37	#include <asm/cpu.h>
	38	#include <asm/elf.h>
	39	#include <asm/fpu.h>
	40	#include <asm/io.h>
	41	#include <asm/irq.h>
	42	#include <asm/irq_regs.h>
	43	#include <asm/loongarch.h>
	44	#include <asm/pgtable.h>
	45	#include <asm/processor.h>
	46	#include <asm/reg.h>
49232773	47	#include <asm/unwind.h>
803b0fc5 HC	48	#include <asm/vdso.h>
803b0fc5 HC	49
09f33601 HC	50	#ifdef CONFIG_STACKPROTECTOR
	51	#include <linux/stackprotector.h>
	52	unsigned long __stack_chk_guard __read_mostly;
	53	EXPORT_SYMBOL(__stack_chk_guard);
	54	#endif
	55
803b0fc5 HC	56	/*
	57	* Idle related variables and functions
	58	*/
	59
	60	unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
	61	EXPORT_SYMBOL(boot_option_idle_override);
	62
46859ac8 HC	63	#ifdef CONFIG_HOTPLUG_CPU
	64	void arch_cpu_idle_dead(void)
	65	{
	66	play_dead();
	67	}
	68	#endif
	69
803b0fc5 HC	70	asmlinkage void ret_from_fork(void);
	71	asmlinkage void ret_from_kernel_thread(void);
	72
	73	void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
	74	{
	75	unsigned long crmd;
	76	unsigned long prmd;
	77	unsigned long euen;
	78
	79	/* New thread loses kernel privileges. */
	80	crmd = regs->csr_crmd & ~(PLV_MASK);
	81	crmd \|= PLV_USER;
	82	regs->csr_crmd = crmd;
	83
	84	prmd = regs->csr_prmd & ~(PLV_MASK);
	85	prmd \|= PLV_USER;
	86	regs->csr_prmd = prmd;
	87
	88	euen = regs->csr_euen & ~(CSR_EUEN_FPEN);
	89	regs->csr_euen = euen;
	90	lose_fpu(0);
	91
	92	clear_thread_flag(TIF_LSX_CTX_LIVE);
	93	clear_thread_flag(TIF_LASX_CTX_LIVE);
	94	clear_used_math();
	95	regs->csr_era = pc;
	96	regs->regs[3] = sp;
	97	}
	98
	99	void exit_thread(struct task_struct *tsk)
	100	{
	101	}
	102
	103	int arch_dup_task_struct(struct task_struct dst, struct task_struct src)
	104	{
	105	/*
	106	* Save any process state which is live in hardware registers to the
	107	* parent context prior to duplication. This prevents the new child
	108	* state becoming stale if the parent is preempted before copy_thread()
	109	* gets a chance to save the parent's live hardware registers to the
	110	* child context.
	111	*/
	112	preempt_disable();
	113
	114	if (is_fpu_owner())
	115	save_fp(current);
	116
	117	preempt_enable();
	118
	119	if (used_math())
	120	memcpy(dst, src, sizeof(struct task_struct));
	121	else
	122	memcpy(dst, src, offsetof(struct task_struct, thread.fpu.fpr));
	123
	124	return 0;
	125	}
	126
	127	/*
	128	* Copy architecture-specific thread state
	129	*/
0626e1c9	130	int copy_thread(struct task_struct p, const struct kernel_clone_args args)
803b0fc5 HC	131	{
803b0fc5 HC	132	unsigned long childksp;
0626e1c9 HC	133	unsigned long tls = args->tls;
	134	unsigned long usp = args->stack;
	135	unsigned long clone_flags = args->flags;
803b0fc5 HC	136	struct pt_regs childregs, regs = current_pt_regs();
803b0fc5 HC	137
b40fa75e	138	childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
803b0fc5 HC	139
	140	/* set up new TSS. */
	141	childregs = (struct pt_regs *) childksp - 1;
	142	/* Put the stack after the struct pt_regs. */
	143	childksp = (unsigned long) childregs;
93a4fa62	144	p->thread.sched_cfa = 0;
803b0fc5 HC	145	p->thread.csr_euen = 0;
	146	p->thread.csr_crmd = csr_read32(LOONGARCH_CSR_CRMD);
	147	p->thread.csr_prmd = csr_read32(LOONGARCH_CSR_PRMD);
	148	p->thread.csr_ecfg = csr_read32(LOONGARCH_CSR_ECFG);
0626e1c9	149	if (unlikely(args->fn)) {
803b0fc5	150	/* kernel thread */
803b0fc5	151	p->thread.reg03 = childksp;
0626e1c9 HC	152	p->thread.reg23 = (unsigned long)args->fn;
	153	p->thread.reg24 = (unsigned long)args->fn_arg;
	154	p->thread.reg01 = (unsigned long)ret_from_kernel_thread;
93a4fa62	155	p->thread.sched_ra = (unsigned long)ret_from_kernel_thread;
803b0fc5 HC	156	memset(childregs, 0, sizeof(struct pt_regs));
	157	childregs->csr_euen = p->thread.csr_euen;
	158	childregs->csr_crmd = p->thread.csr_crmd;
	159	childregs->csr_prmd = p->thread.csr_prmd;
	160	childregs->csr_ecfg = p->thread.csr_ecfg;
e428e961	161	goto out;
803b0fc5 HC	162	}
	163
	164	/* user thread */
	165	childregs = regs;
	166	childregs->regs[4] = 0; /* Child gets zero as return value */
	167	if (usp)
	168	childregs->regs[3] = usp;
	169
	170	p->thread.reg03 = (unsigned long) childregs;
	171	p->thread.reg01 = (unsigned long) ret_from_fork;
93a4fa62	172	p->thread.sched_ra = (unsigned long) ret_from_fork;
803b0fc5 HC	173
	174	/*
	175	* New tasks lose permission to use the fpu. This accelerates context
	176	* switching for most programs since they don't use the fpu.
	177	*/
	178	childregs->csr_euen = 0;
	179
e428e961 HC	180	if (clone_flags & CLONE_SETTLS)
	181	childregs->regs[2] = tls;
	182
	183	out:
803b0fc5 HC	184	clear_tsk_thread_flag(p, TIF_USEDFPU);
	185	clear_tsk_thread_flag(p, TIF_USEDSIMD);
	186	clear_tsk_thread_flag(p, TIF_LSX_CTX_LIVE);
	187	clear_tsk_thread_flag(p, TIF_LASX_CTX_LIVE);
	188
803b0fc5 HC	189	return 0;
	190	}
	191
	192	unsigned long __get_wchan(struct task_struct *task)
	193	{
429a9671	194	unsigned long pc = 0;
93a4fa62 QZ	195	struct unwind_state state;
	196
	197	if (!try_get_task_stack(task))
	198	return 0;
	199
429a9671 JH	200	for (unwind_start(&state, task, NULL);
429a9671 JH	201	!unwind_done(&state); unwind_next_frame(&state)) {
93a4fa62 QZ	202	pc = unwind_get_return_address(&state);
	203	if (!pc)
	204	break;
	205	if (in_sched_functions(pc))
	206	continue;
	207	break;
	208	}
	209
	210	put_task_stack(task);
	211
	212	return pc;
803b0fc5 HC	213	}
803b0fc5 HC	214
49232773 QZ	215	bool in_irq_stack(unsigned long stack, struct stack_info *info)
	216	{
	217	unsigned long nextsp;
	218	unsigned long begin = (unsigned long)this_cpu_read(irq_stack);
	219	unsigned long end = begin + IRQ_STACK_START;
	220
	221	if (stack < begin \|\| stack >= end)
	222	return false;
	223
	224	nextsp = (unsigned long )end;
	225	if (nextsp & (SZREG - 1))
	226	return false;
	227
	228	info->begin = begin;
	229	info->end = end;
	230	info->next_sp = nextsp;
	231	info->type = STACK_TYPE_IRQ;
	232
	233	return true;
	234	}
	235
	236	bool in_task_stack(unsigned long stack, struct task_struct *task,
	237	struct stack_info *info)
	238	{
	239	unsigned long begin = (unsigned long)task_stack_page(task);
b40fa75e	240	unsigned long end = begin + THREAD_SIZE;
49232773 QZ	241
	242	if (stack < begin \|\| stack >= end)
	243	return false;
	244
	245	info->begin = begin;
	246	info->end = end;
	247	info->next_sp = 0;
	248	info->type = STACK_TYPE_TASK;
	249
	250	return true;
	251	}
	252
	253	int get_stack_info(unsigned long stack, struct task_struct *task,
	254	struct stack_info *info)
	255	{
	256	task = task ? : current;
	257
	258	if (!stack \|\| stack & (SZREG - 1))
	259	goto unknown;
	260
	261	if (in_task_stack(stack, task, info))
	262	return 0;
	263
	264	if (task != current)
	265	goto unknown;
	266
	267	if (in_irq_stack(stack, info))
	268	return 0;
	269
	270	unknown:
	271	info->type = STACK_TYPE_UNKNOWN;
	272	return -EINVAL;
	273	}
	274
803b0fc5 HC	275	unsigned long stack_top(void)
	276	{
	277	unsigned long top = TASK_SIZE & PAGE_MASK;
	278
	279	/* Space for the VDSO & data page */
	280	top -= PAGE_ALIGN(current->thread.vdso->size);
	281	top -= PAGE_SIZE;
	282
	283	/* Space to randomize the VDSO base */
	284	if (current->flags & PF_RANDOMIZE)
	285	top -= VDSO_RANDOMIZE_SIZE;
	286
	287	return top;
	288	}
	289
	290	/*
	291	* Don't forget that the stack pointer must be aligned on a 8 bytes
	292	* boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
	293	*/
	294	unsigned long arch_align_stack(unsigned long sp)
	295	{
	296	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
8032bf12	297	sp -= get_random_u32_below(PAGE_SIZE);
803b0fc5 HC	298
	299	return sp & STACK_ALIGN;
	300	}
	301
	302	static DEFINE_PER_CPU(call_single_data_t, backtrace_csd);
	303	static struct cpumask backtrace_csd_busy;
	304
	305	static void handle_backtrace(void *info)
	306	{
	307	nmi_cpu_backtrace(get_irq_regs());
	308	cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy);
	309	}
	310
	311	static void raise_backtrace(cpumask_t *mask)
	312	{
	313	call_single_data_t *csd;
	314	int cpu;
	315
	316	for_each_cpu(cpu, mask) {
	317	/*
	318	* If we previously sent an IPI to the target CPU & it hasn't
	319	* cleared its bit in the busy cpumask then it didn't handle
	320	* our previous IPI & it's not safe for us to reuse the
	321	* call_single_data_t.
	322	*/
	323	if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) {
	324	pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n",
	325	cpu);
	326	continue;
	327	}
	328
	329	csd = &per_cpu(backtrace_csd, cpu);
	330	csd->func = handle_backtrace;
	331	smp_call_function_single_async(cpu, csd);
	332	}
	333	}
	334
	335	void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
	336	{
	337	nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace);
	338	}
	339
	340	#ifdef CONFIG_64BIT
	341	void loongarch_dump_regs64(u64 uregs, const struct pt_regs regs)
	342	{
	343	unsigned int i;
	344
	345	for (i = LOONGARCH_EF_R1; i <= LOONGARCH_EF_R31; i++) {
	346	uregs[i] = regs->regs[i - LOONGARCH_EF_R0];
	347	}
	348
	349	uregs[LOONGARCH_EF_ORIG_A0] = regs->orig_a0;
	350	uregs[LOONGARCH_EF_CSR_ERA] = regs->csr_era;
	351	uregs[LOONGARCH_EF_CSR_BADV] = regs->csr_badvaddr;
	352	uregs[LOONGARCH_EF_CSR_CRMD] = regs->csr_crmd;
	353	uregs[LOONGARCH_EF_CSR_PRMD] = regs->csr_prmd;
	354	uregs[LOONGARCH_EF_CSR_EUEN] = regs->csr_euen;
	355	uregs[LOONGARCH_EF_CSR_ECFG] = regs->csr_ecfg;
	356	uregs[LOONGARCH_EF_CSR_ESTAT] = regs->csr_estat;
	357	}
	358	#endif /* CONFIG_64BIT */