linux/arch/nds32/kernel/process.c

263 lines
6.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/delay.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <asm/elf.h>
#include <asm/proc-fns.h>
#include <asm/fpu.h>
#include <linux/ptrace.h>
#include <linux/reboot.h>
#if IS_ENABLED(CONFIG_LAZY_FPU)
struct task_struct *last_task_used_math;
#endif
extern void setup_mm_for_reboot(char mode);
extern inline void arch_reset(char mode)
{
if (mode == 's') {
/* Use cpu handler, jump to 0 */
cpu_reset(0);
}
}
void (*pm_power_off) (void);
EXPORT_SYMBOL(pm_power_off);
static char reboot_mode_nds32 = 'h';
int __init reboot_setup(char *str)
{
reboot_mode_nds32 = str[0];
return 1;
}
static int cpub_pwroff(void)
{
return 0;
}
__setup("reboot=", reboot_setup);
void machine_halt(void)
{
cpub_pwroff();
}
EXPORT_SYMBOL(machine_halt);
void machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
}
EXPORT_SYMBOL(machine_power_off);
void machine_restart(char *cmd)
{
/*
* Clean and disable cache, and turn off interrupts
*/
cpu_proc_fin();
/*
* Tell the mm system that we are going to reboot -
* we may need it to insert some 1:1 mappings so that
* soft boot works.
*/
setup_mm_for_reboot(reboot_mode_nds32);
/* Execute kernel restart handler call chain */
do_kernel_restart(cmd);
/*
* Now call the architecture specific reboot code.
*/
arch_reset(reboot_mode_nds32);
/*
* Whoops - the architecture was unable to reboot.
* Tell the user!
*/
mdelay(1000);
pr_info("Reboot failed -- System halted\n");
while (1) ;
}
EXPORT_SYMBOL(machine_restart);
void show_regs(struct pt_regs *regs)
{
printk("PC is at %pS\n", (void *)instruction_pointer(regs));
printk("LP is at %pS\n", (void *)regs->lp);
pr_info("pc : [<%08lx>] lp : [<%08lx>] %s\n"
"sp : %08lx fp : %08lx gp : %08lx\n",
instruction_pointer(regs),
regs->lp, print_tainted(), regs->sp, regs->fp, regs->gp);
pr_info("r25: %08lx r24: %08lx\n", regs->uregs[25], regs->uregs[24]);
pr_info("r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
regs->uregs[23], regs->uregs[22],
regs->uregs[21], regs->uregs[20]);
pr_info("r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
regs->uregs[19], regs->uregs[18],
regs->uregs[17], regs->uregs[16]);
pr_info("r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
regs->uregs[15], regs->uregs[14],
regs->uregs[13], regs->uregs[12]);
pr_info("r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
regs->uregs[11], regs->uregs[10],
regs->uregs[9], regs->uregs[8]);
pr_info("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
regs->uregs[7], regs->uregs[6], regs->uregs[5], regs->uregs[4]);
pr_info("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
regs->uregs[3], regs->uregs[2], regs->uregs[1], regs->uregs[0]);
pr_info(" IRQs o%s Segment %s\n",
interrupts_enabled(regs) ? "n" : "ff",
segment_eq(get_fs(), KERNEL_DS)? "kernel" : "user");
}
EXPORT_SYMBOL(show_regs);
void exit_thread(struct task_struct *tsk)
{
#if defined(CONFIG_FPU) && defined(CONFIG_LAZY_FPU)
if (last_task_used_math == tsk)
last_task_used_math = NULL;
#endif
}
void flush_thread(void)
{
#if defined(CONFIG_FPU)
clear_fpu(task_pt_regs(current));
clear_used_math();
# ifdef CONFIG_LAZY_FPU
if (last_task_used_math == current)
last_task_used_math = NULL;
# endif
#endif
}
DEFINE_PER_CPU(struct task_struct *, __entry_task);
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
/* kernel thread fn */
p->thread.cpu_context.r6 = stack_start;
/* kernel thread argument */
p->thread.cpu_context.r7 = stk_sz;
} else {
*childregs = *current_pt_regs();
if (stack_start)
childregs->sp = stack_start;
/* child get zero as ret. */
childregs->uregs[0] = 0;
childregs->osp = 0;
if (clone_flags & CLONE_SETTLS)
childregs->uregs[25] = childregs->uregs[3];
}
/* cpu context switching */
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
p->thread.cpu_context.sp = (unsigned long)childregs;
#if IS_ENABLED(CONFIG_FPU)
if (used_math()) {
# if !IS_ENABLED(CONFIG_LAZY_FPU)
unlazy_fpu(current);
# else
preempt_disable();
if (last_task_used_math == current)
save_fpu(current);
preempt_enable();
# endif
p->thread.fpu = current->thread.fpu;
clear_fpu(task_pt_regs(p));
set_stopped_child_used_math(p);
}
#endif
#ifdef CONFIG_HWZOL
childregs->lb = 0;
childregs->le = 0;
childregs->lc = 0;
#endif
return 0;
}
#if IS_ENABLED(CONFIG_FPU)
struct task_struct *_switch_fpu(struct task_struct *prev, struct task_struct *next)
{
#if !IS_ENABLED(CONFIG_LAZY_FPU)
unlazy_fpu(prev);
#endif
if (!(next->flags & PF_KTHREAD))
clear_fpu(task_pt_regs(next));
return prev;
}
#endif
/*
* fill in the fpe structure for a core dump...
*/
int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
{
int fpvalid = 0;
#if IS_ENABLED(CONFIG_FPU)
struct task_struct *tsk = current;
fpvalid = tsk_used_math(tsk);
if (fpvalid) {
lose_fpu();
memcpy(fpu, &tsk->thread.fpu, sizeof(*fpu));
}
#endif
return fpvalid;
}
EXPORT_SYMBOL(dump_fpu);
unsigned long get_wchan(struct task_struct *p)
{
unsigned long fp, lr;
unsigned long stack_start, stack_end;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
stack_start = (unsigned long)end_of_stack(p);
stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
fp = thread_saved_fp(p);
do {
if (fp < stack_start || fp > stack_end)
return 0;
lr = ((unsigned long *)fp)[0];
if (!in_sched_functions(lr))
return lr;
fp = *(unsigned long *)(fp + 4);
} while (count++ < 16);
}
return 0;
}
EXPORT_SYMBOL(get_wchan);