1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/module.h>
5#include <linux/sched.h>
6#include <linux/sched/task_stack.h>
7#include <linux/sched/debug.h>
8#include <linux/delay.h>
9#include <linux/kallsyms.h>
10#include <linux/uaccess.h>
11#include <linux/ptrace.h>
12#include <linux/elfcore.h>
13
14#include <asm/elf.h>
15#include <abi/reg_ops.h>
16
17struct cpuinfo_csky cpu_data[NR_CPUS];
18
19#ifdef CONFIG_STACKPROTECTOR
20#include <linux/stackprotector.h>
21unsigned long __stack_chk_guard __read_mostly;
22EXPORT_SYMBOL(__stack_chk_guard);
23#endif
24
25asmlinkage void ret_from_fork(void);
26asmlinkage void ret_from_kernel_thread(void);
27
28/*
29 * Some archs flush debug and FPU info here
30 */
31void flush_thread(void){}
32
33int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
34{
35 u64 clone_flags = args->flags;
36 unsigned long usp = args->stack;
37 unsigned long tls = args->tls;
38 struct switch_stack *childstack;
39 struct pt_regs *childregs = task_pt_regs(p);
40
41#ifdef CONFIG_CPU_HAS_FPU
42 save_to_user_fp(&p->thread.user_fp);
43#endif
44
45 childstack = ((struct switch_stack *) childregs) - 1;
46 memset(childstack, 0, sizeof(struct switch_stack));
47
48 /* setup thread.sp for switch_to !!! */
49 p->thread.sp = (unsigned long)childstack;
50
51 if (unlikely(args->fn)) {
52 memset(childregs, 0, sizeof(struct pt_regs));
53 childstack->r15 = (unsigned long) ret_from_kernel_thread;
54 childstack->r10 = (unsigned long) args->fn_arg;
55 childstack->r9 = (unsigned long) args->fn;
56 childregs->sr = mfcr("psr");
57 } else {
58 *childregs = *(current_pt_regs());
59 if (usp)
60 childregs->usp = usp;
61 if (clone_flags & CLONE_SETTLS)
62 task_thread_info(p)->tp_value = childregs->tls
63 = tls;
64
65 childregs->a0 = 0;
66 childstack->r15 = (unsigned long) ret_from_fork;
67 }
68
69 return 0;
70}
71
72/* Fill in the fpu structure for a core dump. */
73int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
74{
75 memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
76 return 1;
77}
78
79int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
80{
81 struct pt_regs *regs = task_pt_regs(tsk);
82
83 /* NOTE: usp is error value. */
84 ELF_CORE_COPY_REGS((*pr_regs), regs)
85
86 return 1;
87}
88
89#ifndef CONFIG_CPU_PM_NONE
90void arch_cpu_idle(void)
91{
92#ifdef CONFIG_CPU_PM_WAIT
93 asm volatile("wait\n");
94#endif
95
96#ifdef CONFIG_CPU_PM_DOZE
97 asm volatile("doze\n");
98#endif
99
100#ifdef CONFIG_CPU_PM_STOP
101 asm volatile("stop\n");
102#endif
103}
104#endif
105

source code of linux/arch/csky/kernel/process.c