csky: Fixup add zero_fp fixup perf backtrace panic
[sfrench/cifs-2.6.git] / arch / csky / kernel / process.c
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 asmlinkage void ret_from_fork(void);
20 asmlinkage void ret_from_kernel_thread(void);
21
22 /*
23  * Some archs flush debug and FPU info here
24  */
25 void flush_thread(void){}
26
27 /*
28  * Return saved PC from a blocked thread
29  */
30 unsigned long thread_saved_pc(struct task_struct *tsk)
31 {
32         struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
33
34         return sw->r15;
35 }
36
37 int copy_thread(unsigned long clone_flags,
38                 unsigned long usp,
39                 unsigned long kthread_arg,
40                 struct task_struct *p)
41 {
42         struct switch_stack *childstack;
43         struct pt_regs *childregs = task_pt_regs(p);
44
45 #ifdef CONFIG_CPU_HAS_FPU
46         save_to_user_fp(&p->thread.user_fp);
47 #endif
48
49         childstack = ((struct switch_stack *) childregs) - 1;
50         memset(childstack, 0, sizeof(struct switch_stack));
51
52         /* setup ksp for switch_to !!! */
53         p->thread.ksp = (unsigned long)childstack;
54
55         if (unlikely(p->flags & PF_KTHREAD)) {
56                 memset(childregs, 0, sizeof(struct pt_regs));
57                 childstack->r15 = (unsigned long) ret_from_kernel_thread;
58                 childstack->r10 = kthread_arg;
59                 childstack->r9 = usp;
60                 childregs->sr = mfcr("psr");
61         } else {
62                 *childregs = *(current_pt_regs());
63                 if (usp)
64                         childregs->usp = usp;
65                 if (clone_flags & CLONE_SETTLS)
66                         task_thread_info(p)->tp_value = childregs->tls
67                                                       = childregs->regs[0];
68
69                 childregs->a0 = 0;
70                 childstack->r15 = (unsigned long) ret_from_fork;
71         }
72
73         return 0;
74 }
75
76 /* Fill in the fpu structure for a core dump.  */
77 int dump_fpu(struct pt_regs *regs, struct user_fp *fpu)
78 {
79         memcpy(fpu, &current->thread.user_fp, sizeof(*fpu));
80         return 1;
81 }
82 EXPORT_SYMBOL(dump_fpu);
83
84 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs)
85 {
86         struct pt_regs *regs = task_pt_regs(tsk);
87
88         /* NOTE: usp is error value. */
89         ELF_CORE_COPY_REGS((*pr_regs), regs)
90
91         return 1;
92 }
93
94 unsigned long get_wchan(struct task_struct *p)
95 {
96         unsigned long lr;
97         unsigned long *fp, *stack_start, *stack_end;
98         int count = 0;
99
100         if (!p || p == current || p->state == TASK_RUNNING)
101                 return 0;
102
103         stack_start = (unsigned long *)end_of_stack(p);
104         stack_end = (unsigned long *)(task_stack_page(p) + THREAD_SIZE);
105
106         fp = (unsigned long *) thread_saved_fp(p);
107         do {
108                 if (fp < stack_start || fp > stack_end)
109                         return 0;
110 #ifdef CONFIG_STACKTRACE
111                 lr = fp[1];
112                 fp = (unsigned long *)fp[0];
113 #else
114                 lr = *fp++;
115 #endif
116                 if (!in_sched_functions(lr) &&
117                     __kernel_text_address(lr))
118                         return lr;
119         } while (count++ < 16);
120
121         return 0;
122 }
123 EXPORT_SYMBOL(get_wchan);
124
125 #ifndef CONFIG_CPU_PM_NONE
126 void arch_cpu_idle(void)
127 {
128 #ifdef CONFIG_CPU_PM_WAIT
129         asm volatile("wait\n");
130 #endif
131
132 #ifdef CONFIG_CPU_PM_DOZE
133         asm volatile("doze\n");
134 #endif
135
136 #ifdef CONFIG_CPU_PM_STOP
137         asm volatile("stop\n");
138 #endif
139         local_irq_enable();
140 }
141 #endif