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/cpu.h>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/sched/debug.h>
14 #include <linux/sched/task_stack.h>
15 #include <linux/tick.h>
16 #include <linux/ptrace.h>
17 #include <linux/uaccess.h>
19 #include <asm/unistd.h>
20 #include <asm/processor.h>
22 #include <asm/stacktrace.h>
23 #include <asm/string.h>
24 #include <asm/switch_to.h>
25 #include <asm/thread_info.h>
26 #include <asm/cpuidle.h>
28 register unsigned long gp_in_global __asm__("gp");
30 #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK)
31 #include <linux/stackprotector.h>
32 unsigned long __stack_chk_guard __read_mostly;
33 EXPORT_SYMBOL(__stack_chk_guard);
36 extern asmlinkage void ret_from_fork(void);
37 extern asmlinkage void ret_from_kernel_thread(void);
39 void arch_cpu_idle(void)
42 raw_local_irq_enable();
45 void __show_regs(struct pt_regs *regs)
47 show_regs_print_info(KERN_DEFAULT);
49 if (!user_mode(regs)) {
50 pr_cont("epc : %pS\n", (void *)regs->epc);
51 pr_cont(" ra : %pS\n", (void *)regs->ra);
54 pr_cont("epc : " REG_FMT " ra : " REG_FMT " sp : " REG_FMT "\n",
55 regs->epc, regs->ra, regs->sp);
56 pr_cont(" gp : " REG_FMT " tp : " REG_FMT " t0 : " REG_FMT "\n",
57 regs->gp, regs->tp, regs->t0);
58 pr_cont(" t1 : " REG_FMT " t2 : " REG_FMT " s0 : " REG_FMT "\n",
59 regs->t1, regs->t2, regs->s0);
60 pr_cont(" s1 : " REG_FMT " a0 : " REG_FMT " a1 : " REG_FMT "\n",
61 regs->s1, regs->a0, regs->a1);
62 pr_cont(" a2 : " REG_FMT " a3 : " REG_FMT " a4 : " REG_FMT "\n",
63 regs->a2, regs->a3, regs->a4);
64 pr_cont(" a5 : " REG_FMT " a6 : " REG_FMT " a7 : " REG_FMT "\n",
65 regs->a5, regs->a6, regs->a7);
66 pr_cont(" s2 : " REG_FMT " s3 : " REG_FMT " s4 : " REG_FMT "\n",
67 regs->s2, regs->s3, regs->s4);
68 pr_cont(" s5 : " REG_FMT " s6 : " REG_FMT " s7 : " REG_FMT "\n",
69 regs->s5, regs->s6, regs->s7);
70 pr_cont(" s8 : " REG_FMT " s9 : " REG_FMT " s10: " REG_FMT "\n",
71 regs->s8, regs->s9, regs->s10);
72 pr_cont(" s11: " REG_FMT " t3 : " REG_FMT " t4 : " REG_FMT "\n",
73 regs->s11, regs->t3, regs->t4);
74 pr_cont(" t5 : " REG_FMT " t6 : " REG_FMT "\n",
77 pr_cont("status: " REG_FMT " badaddr: " REG_FMT " cause: " REG_FMT "\n",
78 regs->status, regs->badaddr, regs->cause);
80 void show_regs(struct pt_regs *regs)
84 dump_backtrace(regs, NULL, KERN_DEFAULT);
87 void start_thread(struct pt_regs *regs, unsigned long pc,
90 regs->status = SR_PIE;
92 regs->status |= SR_FS_INITIAL;
94 * Restore the initial value to the FP register
95 * before starting the user program.
97 fstate_restore(current, regs);
103 void flush_thread(void)
107 * Reset FPU state and context
108 * frm: round to nearest, ties to even (IEEE default)
109 * fflags: accrued exceptions cleared
111 fstate_off(current, task_pt_regs(current));
112 memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate));
116 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
118 fstate_save(src, task_pt_regs(src));
123 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
124 struct task_struct *p, unsigned long tls)
126 struct pt_regs *childregs = task_pt_regs(p);
128 /* p->thread holds context to be restored by __switch_to() */
129 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
131 memset(childregs, 0, sizeof(struct pt_regs));
132 childregs->gp = gp_in_global;
133 /* Supervisor/Machine, irqs on: */
134 childregs->status = SR_PP | SR_PIE;
136 p->thread.ra = (unsigned long)ret_from_kernel_thread;
137 p->thread.s[0] = usp; /* fn */
138 p->thread.s[1] = arg;
140 *childregs = *(current_pt_regs());
141 if (usp) /* User fork */
143 if (clone_flags & CLONE_SETTLS)
145 childregs->a0 = 0; /* Return value of fork() */
146 p->thread.ra = (unsigned long)ret_from_fork;
148 p->thread.sp = (unsigned long)childregs; /* kernel sp */