1 // SPDX-License-Identifier: GPL-2.0-or-later
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
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/tick.h>
14 #include <linux/ptrace.h>
15 #include <linux/uaccess.h>
17 #include <asm/unistd.h>
18 #include <asm/processor.h>
20 #include <asm/string.h>
21 #include <asm/switch_to.h>
23 extern asmlinkage void ret_from_fork(void);
24 extern asmlinkage void ret_from_kernel_thread(void);
26 void arch_cpu_idle(void)
32 void show_regs(struct pt_regs *regs)
34 show_regs_print_info(KERN_DEFAULT);
36 pr_cont("sepc: " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
37 regs->sepc, regs->ra, regs->sp);
38 pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
39 regs->gp, regs->tp, regs->t0);
40 pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
41 regs->t1, regs->t2, regs->s0);
42 pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
43 regs->s1, regs->a0, regs->a1);
44 pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
45 regs->a2, regs->a3, regs->a4);
46 pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
47 regs->a5, regs->a6, regs->a7);
48 pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
49 regs->s2, regs->s3, regs->s4);
50 pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
51 regs->s5, regs->s6, regs->s7);
52 pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
53 regs->s8, regs->s9, regs->s10);
54 pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
55 regs->s11, regs->t3, regs->t4);
56 pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
59 pr_cont("sstatus: " REG_FMT " sbadaddr: " REG_FMT " scause: " REG_FMT "\n",
60 regs->sstatus, regs->sbadaddr, regs->scause);
63 void start_thread(struct pt_regs *regs, unsigned long pc,
66 regs->sstatus = SR_SPIE;
68 regs->sstatus |= SR_FS_INITIAL;
70 * Restore the initial value to the FP register
71 * before starting the user program.
73 fstate_restore(current, regs);
80 void flush_thread(void)
84 * Reset FPU state and context
85 * frm: round to nearest, ties to even (IEEE default)
86 * fflags: accrued exceptions cleared
88 fstate_off(current, task_pt_regs(current));
89 memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate));
93 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
95 fstate_save(src, task_pt_regs(src));
100 int copy_thread(unsigned long clone_flags, unsigned long usp,
101 unsigned long arg, struct task_struct *p)
103 struct pt_regs *childregs = task_pt_regs(p);
105 /* p->thread holds context to be restored by __switch_to() */
106 if (unlikely(p->flags & PF_KTHREAD)) {
108 const register unsigned long gp __asm__ ("gp");
109 memset(childregs, 0, sizeof(struct pt_regs));
111 childregs->sstatus = SR_SPP | SR_SPIE; /* Supervisor, irqs on */
113 p->thread.ra = (unsigned long)ret_from_kernel_thread;
114 p->thread.s[0] = usp; /* fn */
115 p->thread.s[1] = arg;
117 *childregs = *(current_pt_regs());
118 if (usp) /* User fork */
120 if (clone_flags & CLONE_SETTLS)
121 childregs->tp = childregs->a5;
122 childregs->a0 = 0; /* Return value of fork() */
123 p->thread.ra = (unsigned long)ret_from_fork;
125 p->thread.sp = (unsigned long)childregs; /* kernel sp */