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1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2005-2017 Andes Technology Corporation
3
4#include <linux/sched.h>
5#include <linux/sched/debug.h>
6#include <linux/sched/task_stack.h>
7#include <linux/delay.h>
8#include <linux/kallsyms.h>
9#include <linux/uaccess.h>
10#include <asm/elf.h>
11#include <asm/proc-fns.h>
12#include <asm/fpu.h>
13#include <linux/ptrace.h>
14#include <linux/reboot.h>
15
16#if IS_ENABLED(CONFIG_LAZY_FPU)
17struct task_struct *last_task_used_math;
18#endif
19
20extern void setup_mm_for_reboot(char mode);
21
22extern inline void arch_reset(char mode)
23{
24 if (mode == 's') {
25 /* Use cpu handler, jump to 0 */
26 cpu_reset(0);
27 }
28}
29
30void (*pm_power_off) (void);
31EXPORT_SYMBOL(pm_power_off);
32
33static char reboot_mode_nds32 = 'h';
34
35int __init reboot_setup(char *str)
36{
37 reboot_mode_nds32 = str[0];
38 return 1;
39}
40
41static int cpub_pwroff(void)
42{
43 return 0;
44}
45
46__setup("reboot=", reboot_setup);
47
48void machine_halt(void)
49{
50 cpub_pwroff();
51}
52
53EXPORT_SYMBOL(machine_halt);
54
55void machine_power_off(void)
56{
57 if (pm_power_off)
58 pm_power_off();
59}
60
61EXPORT_SYMBOL(machine_power_off);
62
63void machine_restart(char *cmd)
64{
65 /*
66 * Clean and disable cache, and turn off interrupts
67 */
68 cpu_proc_fin();
69
70 /*
71 * Tell the mm system that we are going to reboot -
72 * we may need it to insert some 1:1 mappings so that
73 * soft boot works.
74 */
75 setup_mm_for_reboot(reboot_mode_nds32);
76
77 /* Execute kernel restart handler call chain */
78 do_kernel_restart(cmd);
79
80 /*
81 * Now call the architecture specific reboot code.
82 */
83 arch_reset(reboot_mode_nds32);
84
85 /*
86 * Whoops - the architecture was unable to reboot.
87 * Tell the user!
88 */
89 mdelay(1000);
90 pr_info("Reboot failed -- System halted\n");
91 while (1) ;
92}
93
94EXPORT_SYMBOL(machine_restart);
95
96void show_regs(struct pt_regs *regs)
97{
98 printk("PC is at %pS\n", (void *)instruction_pointer(regs));
99 printk("LP is at %pS\n", (void *)regs->lp);
100 pr_info("pc : [<%08lx>] lp : [<%08lx>] %s\n"
101 "sp : %08lx fp : %08lx gp : %08lx\n",
102 instruction_pointer(regs),
103 regs->lp, print_tainted(), regs->sp, regs->fp, regs->gp);
104 pr_info("r25: %08lx r24: %08lx\n", regs->uregs[25], regs->uregs[24]);
105
106 pr_info("r23: %08lx r22: %08lx r21: %08lx r20: %08lx\n",
107 regs->uregs[23], regs->uregs[22],
108 regs->uregs[21], regs->uregs[20]);
109 pr_info("r19: %08lx r18: %08lx r17: %08lx r16: %08lx\n",
110 regs->uregs[19], regs->uregs[18],
111 regs->uregs[17], regs->uregs[16]);
112 pr_info("r15: %08lx r14: %08lx r13: %08lx r12: %08lx\n",
113 regs->uregs[15], regs->uregs[14],
114 regs->uregs[13], regs->uregs[12]);
115 pr_info("r11: %08lx r10: %08lx r9 : %08lx r8 : %08lx\n",
116 regs->uregs[11], regs->uregs[10],
117 regs->uregs[9], regs->uregs[8]);
118 pr_info("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
119 regs->uregs[7], regs->uregs[6], regs->uregs[5], regs->uregs[4]);
120 pr_info("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
121 regs->uregs[3], regs->uregs[2], regs->uregs[1], regs->uregs[0]);
122 pr_info(" IRQs o%s Segment %s\n",
123 interrupts_enabled(regs) ? "n" : "ff",
124 segment_eq(get_fs(), KERNEL_DS)? "kernel" : "user");
125}
126
127EXPORT_SYMBOL(show_regs);
128
129void exit_thread(struct task_struct *tsk)
130{
131#if defined(CONFIG_FPU) && defined(CONFIG_LAZY_FPU)
132 if (last_task_used_math == tsk)
133 last_task_used_math = NULL;
134#endif
135}
136
137void flush_thread(void)
138{
139#if defined(CONFIG_FPU)
140 clear_fpu(task_pt_regs(current));
141 clear_used_math();
142# ifdef CONFIG_LAZY_FPU
143 if (last_task_used_math == current)
144 last_task_used_math = NULL;
145# endif
146#endif
147}
148
149DEFINE_PER_CPU(struct task_struct *, __entry_task);
150
151asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
152int copy_thread(unsigned long clone_flags, unsigned long stack_start,
153 unsigned long stk_sz, struct task_struct *p)
154{
155 struct pt_regs *childregs = task_pt_regs(p);
156
157 memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
158
159 if (unlikely(p->flags & PF_KTHREAD)) {
160 memset(childregs, 0, sizeof(struct pt_regs));
161 /* kernel thread fn */
162 p->thread.cpu_context.r6 = stack_start;
163 /* kernel thread argument */
164 p->thread.cpu_context.r7 = stk_sz;
165 } else {
166 *childregs = *current_pt_regs();
167 if (stack_start)
168 childregs->sp = stack_start;
169 /* child get zero as ret. */
170 childregs->uregs[0] = 0;
171 childregs->osp = 0;
172 if (clone_flags & CLONE_SETTLS)
173 childregs->uregs[25] = childregs->uregs[3];
174 }
175 /* cpu context switching */
176 p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
177 p->thread.cpu_context.sp = (unsigned long)childregs;
178
179#if IS_ENABLED(CONFIG_FPU)
180 if (used_math()) {
181# if !IS_ENABLED(CONFIG_LAZY_FPU)
182 unlazy_fpu(current);
183# else
184 preempt_disable();
185 if (last_task_used_math == current)
186 save_fpu(current);
187 preempt_enable();
188# endif
189 p->thread.fpu = current->thread.fpu;
190 clear_fpu(task_pt_regs(p));
191 set_stopped_child_used_math(p);
192 }
193#endif
194
195#ifdef CONFIG_HWZOL
196 childregs->lb = 0;
197 childregs->le = 0;
198 childregs->lc = 0;
199#endif
200
201 return 0;
202}
203
204#if IS_ENABLED(CONFIG_FPU)
205struct task_struct *_switch_fpu(struct task_struct *prev, struct task_struct *next)
206{
207#if !IS_ENABLED(CONFIG_LAZY_FPU)
208 unlazy_fpu(prev);
209#endif
210 if (!(next->flags & PF_KTHREAD))
211 clear_fpu(task_pt_regs(next));
212 return prev;
213}
214#endif
215
216/*
217 * fill in the fpe structure for a core dump...
218 */
219int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
220{
221 int fpvalid = 0;
222#if IS_ENABLED(CONFIG_FPU)
223 struct task_struct *tsk = current;
224
225 fpvalid = tsk_used_math(tsk);
226 if (fpvalid) {
227 lose_fpu();
228 memcpy(fpu, &tsk->thread.fpu, sizeof(*fpu));
229 }
230#endif
231 return fpvalid;
232}
233
234EXPORT_SYMBOL(dump_fpu);
235
236unsigned long get_wchan(struct task_struct *p)
237{
238 unsigned long fp, lr;
239 unsigned long stack_start, stack_end;
240 int count = 0;
241
242 if (!p || p == current || p->state == TASK_RUNNING)
243 return 0;
244
245 if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
246 stack_start = (unsigned long)end_of_stack(p);
247 stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
248
249 fp = thread_saved_fp(p);
250 do {
251 if (fp < stack_start || fp > stack_end)
252 return 0;
253 lr = ((unsigned long *)fp)[0];
254 if (!in_sched_functions(lr))
255 return lr;
256 fp = *(unsigned long *)(fp + 4);
257 } while (count++ < 16);
258 }
259 return 0;
260}
261
262EXPORT_SYMBOL(get_wchan);