xref: /openbmc/linux/arch/csky/kernel/process.c (revision 88f4ede4)
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/version.h>
6 #include <linux/sched.h>
7 #include <linux/sched/task_stack.h>
8 #include <linux/sched/debug.h>
9 #include <linux/delay.h>
10 #include <linux/kallsyms.h>
11 #include <linux/uaccess.h>
12 #include <linux/ptrace.h>
13 
14 #include <asm/elf.h>
15 #include <abi/reg_ops.h>
16 
17 struct cpuinfo_csky cpu_data[NR_CPUS];
18 
19 #ifdef CONFIG_STACKPROTECTOR
20 #include <linux/stackprotector.h>
21 unsigned long __stack_chk_guard __read_mostly;
22 EXPORT_SYMBOL(__stack_chk_guard);
23 #endif
24 
25 asmlinkage void ret_from_fork(void);
26 asmlinkage void ret_from_kernel_thread(void);
27 
28 /*
29  * Some archs flush debug and FPU info here
30  */
31 void flush_thread(void){}
32 
33 int copy_thread(unsigned long clone_flags,
34 		unsigned long usp,
35 		unsigned long kthread_arg,
36 		struct task_struct *p,
37 		unsigned long tls)
38 {
39 	struct switch_stack *childstack;
40 	struct pt_regs *childregs = task_pt_regs(p);
41 
42 #ifdef CONFIG_CPU_HAS_FPU
43 	save_to_user_fp(&p->thread.user_fp);
44 #endif
45 
46 	childstack = ((struct switch_stack *) childregs) - 1;
47 	memset(childstack, 0, sizeof(struct switch_stack));
48 
49 	/* setup thread.sp for switch_to !!! */
50 	p->thread.sp = (unsigned long)childstack;
51 
52 	if (unlikely(p->flags & PF_KTHREAD)) {
53 		memset(childregs, 0, sizeof(struct pt_regs));
54 		childstack->r15 = (unsigned long) ret_from_kernel_thread;
55 		childstack->r10 = kthread_arg;
56 		childstack->r9 = usp;
57 		childregs->sr = mfcr("psr");
58 	} else {
59 		*childregs = *(current_pt_regs());
60 		if (usp)
61 			childregs->usp = usp;
62 		if (clone_flags & CLONE_SETTLS)
63 			task_thread_info(p)->tp_value = childregs->tls
64 						      = tls;
65 
66 		childregs->a0 = 0;
67 		childstack->r15 = (unsigned long) ret_from_fork;
68 	}
69 
70 	return 0;
71 }
72 
73 /* Fill in the fpu structure for a core dump.  */
74 int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
75 {
76 	memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
77 	return 1;
78 }
79 EXPORT_SYMBOL(dump_fpu);
80 
81 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
82 {
83 	struct pt_regs *regs = task_pt_regs(tsk);
84 
85 	/* NOTE: usp is error value. */
86 	ELF_CORE_COPY_REGS((*pr_regs), regs)
87 
88 	return 1;
89 }
90 
91 #ifndef CONFIG_CPU_PM_NONE
92 void arch_cpu_idle(void)
93 {
94 #ifdef CONFIG_CPU_PM_WAIT
95 	asm volatile("wait\n");
96 #endif
97 
98 #ifdef CONFIG_CPU_PM_DOZE
99 	asm volatile("doze\n");
100 #endif
101 
102 #ifdef CONFIG_CPU_PM_STOP
103 	asm volatile("stop\n");
104 #endif
105 	raw_local_irq_enable();
106 }
107 #endif
108