1/*
2 * Architecture-dependent parts of process handling.
3 *
4 * Copyright (C) 2013 Altera Corporation
5 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
6 * Copyright (C) 2009 Wind River Systems Inc
7 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
8 * Copyright (C) 2004 Microtronix Datacom Ltd
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
12 * for more details.
13 */
14
15#include <linux/export.h>
16#include <linux/sched.h>
17#include <linux/sched/debug.h>
18#include <linux/sched/task.h>
19#include <linux/sched/task_stack.h>
20#include <linux/mm_types.h>
21#include <linux/tick.h>
22#include <linux/uaccess.h>
23
24#include <asm/unistd.h>
25#include <asm/traps.h>
26#include <asm/cpuinfo.h>
27
28asmlinkage void ret_from_fork(void);
29asmlinkage void ret_from_kernel_thread(void);
30
31void (*pm_power_off)(void) = NULL;
32EXPORT_SYMBOL(pm_power_off);
33
34void arch_cpu_idle(void)
35{
36}
37
38/*
39 * The development boards have no way to pull a board reset. Just jump to the
40 * cpu reset address and let the boot loader or the code in head.S take care of
41 * resetting peripherals.
42 */
43void machine_restart(char *__unused)
44{
45 pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);
46 local_irq_disable();
47 __asm__ __volatile__ (
48 "jmp %0\n\t"
49 :
50 : "r" (cpuinfo.reset_addr)
51 : "r4");
52}
53
54void machine_halt(void)
55{
56 pr_notice("Machine halt...\n");
57 local_irq_disable();
58 for (;;)
59 ;
60}
61
62/*
63 * There is no way to power off the development boards. So just spin for now. If
64 * we ever have a way of resetting a board using a GPIO we should add that here.
65 */
66void machine_power_off(void)
67{
68 pr_notice("Machine power off...\n");
69 local_irq_disable();
70 for (;;)
71 ;
72}
73
74void show_regs(struct pt_regs *regs)
75{
76 pr_notice("\n");
77 show_regs_print_info(KERN_DEFAULT);
78
79 pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",
80 regs->r1, regs->r2, regs->r3, regs->r4);
81
82 pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",
83 regs->r5, regs->r6, regs->r7, regs->r8);
84
85 pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",
86 regs->r9, regs->r10, regs->r11, regs->r12);
87
88 pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",
89 regs->r13, regs->r14, regs->r15);
90
91 pr_notice("ra: %08lx fp: %08lx sp: %08lx gp: %08lx\n",
92 regs->ra, regs->fp, regs->sp, regs->gp);
93
94 pr_notice("ea: %08lx estatus: %08lx\n",
95 regs->ea, regs->estatus);
96}
97
98void flush_thread(void)
99{
100}
101
102int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
103{
104 unsigned long clone_flags = args->flags;
105 unsigned long usp = args->stack;
106 unsigned long tls = args->tls;
107 struct pt_regs *childregs = task_pt_regs(p);
108 struct pt_regs *regs;
109 struct switch_stack *stack;
110 struct switch_stack *childstack =
111 ((struct switch_stack *)childregs) - 1;
112
113 if (unlikely(args->fn)) {
114 memset(childstack, 0,
115 sizeof(struct switch_stack) + sizeof(struct pt_regs));
116
117 childstack->r16 = (unsigned long) args->fn;
118 childstack->r17 = (unsigned long) args->fn_arg;
119 childstack->ra = (unsigned long) ret_from_kernel_thread;
120 childregs->estatus = STATUS_PIE;
121 childregs->sp = (unsigned long) childstack;
122
123 p->thread.ksp = (unsigned long) childstack;
124 p->thread.kregs = childregs;
125 return 0;
126 }
127
128 regs = current_pt_regs();
129 *childregs = *regs;
130 childregs->r2 = 0; /* Set the return value for the child. */
131 childregs->r7 = 0;
132
133 stack = ((struct switch_stack *) regs) - 1;
134 *childstack = *stack;
135 childstack->ra = (unsigned long)ret_from_fork;
136 p->thread.kregs = childregs;
137 p->thread.ksp = (unsigned long) childstack;
138
139 if (usp)
140 childregs->sp = usp;
141
142 /* Initialize tls register. */
143 if (clone_flags & CLONE_SETTLS)
144 childstack->r23 = tls;
145
146 return 0;
147}
148
149/*
150 * Generic dumping code. Used for panic and debug.
151 */
152void dump(struct pt_regs *fp)
153{
154 unsigned long *sp;
155 unsigned char *tp;
156 int i;
157
158 pr_emerg("\nCURRENT PROCESS:\n\n");
159 pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);
160
161 if (current->mm) {
162 pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
163 (int) current->mm->start_code,
164 (int) current->mm->end_code,
165 (int) current->mm->start_data,
166 (int) current->mm->end_data,
167 (int) current->mm->end_data,
168 (int) current->mm->brk);
169 pr_emerg("USER-STACK=%08x KERNEL-STACK=%08x\n\n",
170 (int) current->mm->start_stack,
171 (int)(((unsigned long) current) + THREAD_SIZE));
172 }
173
174 pr_emerg("PC: %08lx\n", fp->ea);
175 pr_emerg("SR: %08lx SP: %08lx\n",
176 (long) fp->estatus, (long) fp);
177
178 pr_emerg("r1: %08lx r2: %08lx r3: %08lx\n",
179 fp->r1, fp->r2, fp->r3);
180
181 pr_emerg("r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
182 fp->r4, fp->r5, fp->r6, fp->r7);
183 pr_emerg("r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
184 fp->r8, fp->r9, fp->r10, fp->r11);
185 pr_emerg("r12: %08lx r13: %08lx r14: %08lx r15: %08lx\n",
186 fp->r12, fp->r13, fp->r14, fp->r15);
187 pr_emerg("or2: %08lx ra: %08lx fp: %08lx sp: %08lx\n",
188 fp->orig_r2, fp->ra, fp->fp, fp->sp);
189 pr_emerg("\nUSP: %08x TRAPFRAME: %08x\n",
190 (unsigned int) fp->sp, (unsigned int) fp);
191
192 pr_emerg("\nCODE:");
193 tp = ((unsigned char *) fp->ea) - 0x20;
194 for (sp = (unsigned long *) tp, i = 0; (i < 0x40); i += 4) {
195 if ((i % 0x10) == 0)
196 pr_emerg("\n%08x: ", (int) (tp + i));
197 pr_emerg("%08x ", (int) *sp++);
198 }
199 pr_emerg("\n");
200
201 pr_emerg("\nKERNEL STACK:");
202 tp = ((unsigned char *) fp) - 0x40;
203 for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
204 if ((i % 0x10) == 0)
205 pr_emerg("\n%08x: ", (int) (tp + i));
206 pr_emerg("%08x ", (int) *sp++);
207 }
208 pr_emerg("\n");
209 pr_emerg("\n");
210
211 pr_emerg("\nUSER STACK:");
212 tp = (unsigned char *) (fp->sp - 0x10);
213 for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
214 if ((i % 0x10) == 0)
215 pr_emerg("\n%08x: ", (int) (tp + i));
216 pr_emerg("%08x ", (int) *sp++);
217 }
218 pr_emerg("\n\n");
219}
220
221unsigned long __get_wchan(struct task_struct *p)
222{
223 unsigned long fp, pc;
224 unsigned long stack_page;
225 int count = 0;
226
227 stack_page = (unsigned long)p;
228 fp = ((struct switch_stack *)p->thread.ksp)->fp; /* ;dgt2 */
229 do {
230 if (fp < stack_page+sizeof(struct task_struct) ||
231 fp >= 8184+stack_page) /* ;dgt2;tmp */
232 return 0;
233 pc = ((unsigned long *)fp)[1];
234 if (!in_sched_functions(addr: pc))
235 return pc;
236 fp = *(unsigned long *) fp;
237 } while (count++ < 16); /* ;dgt2;tmp */
238 return 0;
239}
240
241/*
242 * Do necessary setup to start up a newly executed thread.
243 * Will startup in user mode (status_extension = 0).
244 */
245void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
246{
247 memset((void *) regs, 0, sizeof(struct pt_regs));
248 regs->estatus = ESTATUS_EPIE | ESTATUS_EU;
249 regs->ea = pc;
250 regs->sp = sp;
251}
252
253asmlinkage int nios2_clone(unsigned long clone_flags, unsigned long newsp,
254 int __user *parent_tidptr, int __user *child_tidptr,
255 unsigned long tls)
256{
257 struct kernel_clone_args args = {
258 .flags = (lower_32_bits(clone_flags) & ~CSIGNAL),
259 .pidfd = parent_tidptr,
260 .child_tid = child_tidptr,
261 .parent_tid = parent_tidptr,
262 .exit_signal = (lower_32_bits(clone_flags) & CSIGNAL),
263 .stack = newsp,
264 .tls = tls,
265 };
266
267 return kernel_clone(kargs: &args);
268}
269

source code of linux/arch/nios2/kernel/process.c