xref: /openbmc/linux/arch/csky/kernel/process.c (revision dd5e5554)
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 
13 #include <asm/elf.h>
14 #include <abi/reg_ops.h>
15 
16 struct cpuinfo_csky cpu_data[NR_CPUS];
17 
18 #ifdef CONFIG_STACKPROTECTOR
19 #include <linux/stackprotector.h>
20 unsigned long __stack_chk_guard __read_mostly;
21 EXPORT_SYMBOL(__stack_chk_guard);
22 #endif
23 
24 asmlinkage void ret_from_fork(void);
25 asmlinkage void ret_from_kernel_thread(void);
26 
27 /*
28  * Some archs flush debug and FPU info here
29  */
30 void flush_thread(void){}
31 
32 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
33 {
34 	unsigned long clone_flags = args->flags;
35 	unsigned long usp = args->stack;
36 	unsigned long tls = args->tls;
37 	struct switch_stack *childstack;
38 	struct pt_regs *childregs = task_pt_regs(p);
39 
40 #ifdef CONFIG_CPU_HAS_FPU
41 	save_to_user_fp(&p->thread.user_fp);
42 #endif
43 
44 	childstack = ((struct switch_stack *) childregs) - 1;
45 	memset(childstack, 0, sizeof(struct switch_stack));
46 
47 	/* setup thread.sp for switch_to !!! */
48 	p->thread.sp = (unsigned long)childstack;
49 
50 	if (unlikely(args->fn)) {
51 		memset(childregs, 0, sizeof(struct pt_regs));
52 		childstack->r15 = (unsigned long) ret_from_kernel_thread;
53 		childstack->r10 = (unsigned long) args->fn_arg;
54 		childstack->r9 = (unsigned long) args->fn;
55 		childregs->sr = mfcr("psr");
56 	} else {
57 		*childregs = *(current_pt_regs());
58 		if (usp)
59 			childregs->usp = usp;
60 		if (clone_flags & CLONE_SETTLS)
61 			task_thread_info(p)->tp_value = childregs->tls
62 						      = tls;
63 
64 		childregs->a0 = 0;
65 		childstack->r15 = (unsigned long) ret_from_fork;
66 	}
67 
68 	return 0;
69 }
70 
71 /* Fill in the fpu structure for a core dump.  */
72 int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
73 {
74 	memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
75 	return 1;
76 }
77 EXPORT_SYMBOL(dump_fpu);
78 
79 int 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
90 void 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 	raw_local_irq_enable();
104 }
105 #endif
106