xref: /openbmc/linux/arch/nios2/kernel/process.c (revision 8bbecfb4)
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 
28 asmlinkage void ret_from_fork(void);
29 asmlinkage void ret_from_kernel_thread(void);
30 
31 void (*pm_power_off)(void) = NULL;
32 EXPORT_SYMBOL(pm_power_off);
33 
34 void arch_cpu_idle(void)
35 {
36 	raw_local_irq_enable();
37 }
38 
39 /*
40  * The development boards have no way to pull a board reset. Just jump to the
41  * cpu reset address and let the boot loader or the code in head.S take care of
42  * resetting peripherals.
43  */
44 void machine_restart(char *__unused)
45 {
46 	pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);
47 	local_irq_disable();
48 	__asm__ __volatile__ (
49 	"jmp	%0\n\t"
50 	:
51 	: "r" (cpuinfo.reset_addr)
52 	: "r4");
53 }
54 
55 void machine_halt(void)
56 {
57 	pr_notice("Machine halt...\n");
58 	local_irq_disable();
59 	for (;;)
60 		;
61 }
62 
63 /*
64  * There is no way to power off the development boards. So just spin for now. If
65  * we ever have a way of resetting a board using a GPIO we should add that here.
66  */
67 void machine_power_off(void)
68 {
69 	pr_notice("Machine power off...\n");
70 	local_irq_disable();
71 	for (;;)
72 		;
73 }
74 
75 void show_regs(struct pt_regs *regs)
76 {
77 	pr_notice("\n");
78 	show_regs_print_info(KERN_DEFAULT);
79 
80 	pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",
81 		regs->r1,  regs->r2,  regs->r3,  regs->r4);
82 
83 	pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",
84 		regs->r5,  regs->r6,  regs->r7,  regs->r8);
85 
86 	pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",
87 		regs->r9,  regs->r10, regs->r11, regs->r12);
88 
89 	pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",
90 		regs->r13, regs->r14, regs->r15);
91 
92 	pr_notice("ra: %08lx fp:  %08lx sp: %08lx gp: %08lx\n",
93 		regs->ra,  regs->fp,  regs->sp,  regs->gp);
94 
95 	pr_notice("ea: %08lx estatus: %08lx\n",
96 		regs->ea,  regs->estatus);
97 }
98 
99 void flush_thread(void)
100 {
101 }
102 
103 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
104 		struct task_struct *p, unsigned long tls)
105 {
106 	struct pt_regs *childregs = task_pt_regs(p);
107 	struct pt_regs *regs;
108 	struct switch_stack *stack;
109 	struct switch_stack *childstack =
110 		((struct switch_stack *)childregs) - 1;
111 
112 	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
113 		memset(childstack, 0,
114 			sizeof(struct switch_stack) + sizeof(struct pt_regs));
115 
116 		childstack->r16 = usp;		/* fn */
117 		childstack->r17 = arg;
118 		childstack->ra = (unsigned long) ret_from_kernel_thread;
119 		childregs->estatus = STATUS_PIE;
120 		childregs->sp = (unsigned long) childstack;
121 
122 		p->thread.ksp = (unsigned long) childstack;
123 		p->thread.kregs = childregs;
124 		return 0;
125 	}
126 
127 	regs = current_pt_regs();
128 	*childregs = *regs;
129 	childregs->r2 = 0;	/* Set the return value for the child. */
130 	childregs->r7 = 0;
131 
132 	stack = ((struct switch_stack *) regs) - 1;
133 	*childstack = *stack;
134 	childstack->ra = (unsigned long)ret_from_fork;
135 	p->thread.kregs = childregs;
136 	p->thread.ksp = (unsigned long) childstack;
137 
138 	if (usp)
139 		childregs->sp = usp;
140 
141 	/* Initialize tls register. */
142 	if (clone_flags & CLONE_SETTLS)
143 		childstack->r23 = tls;
144 
145 	return 0;
146 }
147 
148 /*
149  *	Generic dumping code. Used for panic and debug.
150  */
151 void dump(struct pt_regs *fp)
152 {
153 	unsigned long	*sp;
154 	unsigned char	*tp;
155 	int		i;
156 
157 	pr_emerg("\nCURRENT PROCESS:\n\n");
158 	pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);
159 
160 	if (current->mm) {
161 		pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
162 			(int) current->mm->start_code,
163 			(int) current->mm->end_code,
164 			(int) current->mm->start_data,
165 			(int) current->mm->end_data,
166 			(int) current->mm->end_data,
167 			(int) current->mm->brk);
168 		pr_emerg("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
169 			(int) current->mm->start_stack,
170 			(int)(((unsigned long) current) + THREAD_SIZE));
171 	}
172 
173 	pr_emerg("PC: %08lx\n", fp->ea);
174 	pr_emerg("SR: %08lx    SP: %08lx\n",
175 		(long) fp->estatus, (long) fp);
176 
177 	pr_emerg("r1: %08lx    r2: %08lx    r3: %08lx\n",
178 		fp->r1, fp->r2, fp->r3);
179 
180 	pr_emerg("r4: %08lx    r5: %08lx    r6: %08lx    r7: %08lx\n",
181 		fp->r4, fp->r5, fp->r6, fp->r7);
182 	pr_emerg("r8: %08lx    r9: %08lx    r10: %08lx    r11: %08lx\n",
183 		fp->r8, fp->r9, fp->r10, fp->r11);
184 	pr_emerg("r12: %08lx  r13: %08lx    r14: %08lx    r15: %08lx\n",
185 		fp->r12, fp->r13, fp->r14, fp->r15);
186 	pr_emerg("or2: %08lx   ra: %08lx     fp: %08lx    sp: %08lx\n",
187 		fp->orig_r2, fp->ra, fp->fp, fp->sp);
188 	pr_emerg("\nUSP: %08x   TRAPFRAME: %08x\n",
189 		(unsigned int) fp->sp, (unsigned int) fp);
190 
191 	pr_emerg("\nCODE:");
192 	tp = ((unsigned char *) fp->ea) - 0x20;
193 	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
194 		if ((i % 0x10) == 0)
195 			pr_emerg("\n%08x: ", (int) (tp + i));
196 		pr_emerg("%08x ", (int) *sp++);
197 	}
198 	pr_emerg("\n");
199 
200 	pr_emerg("\nKERNEL STACK:");
201 	tp = ((unsigned char *) fp) - 0x40;
202 	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
203 		if ((i % 0x10) == 0)
204 			pr_emerg("\n%08x: ", (int) (tp + i));
205 		pr_emerg("%08x ", (int) *sp++);
206 	}
207 	pr_emerg("\n");
208 	pr_emerg("\n");
209 
210 	pr_emerg("\nUSER STACK:");
211 	tp = (unsigned char *) (fp->sp - 0x10);
212 	for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
213 		if ((i % 0x10) == 0)
214 			pr_emerg("\n%08x: ", (int) (tp + i));
215 		pr_emerg("%08x ", (int) *sp++);
216 	}
217 	pr_emerg("\n\n");
218 }
219 
220 unsigned long get_wchan(struct task_struct *p)
221 {
222 	unsigned long fp, pc;
223 	unsigned long stack_page;
224 	int count = 0;
225 
226 	if (!p || p == current || p->state == TASK_RUNNING)
227 		return 0;
228 
229 	stack_page = (unsigned long)p;
230 	fp = ((struct switch_stack *)p->thread.ksp)->fp;	/* ;dgt2 */
231 	do {
232 		if (fp < stack_page+sizeof(struct task_struct) ||
233 			fp >= 8184+stack_page)	/* ;dgt2;tmp */
234 			return 0;
235 		pc = ((unsigned long *)fp)[1];
236 		if (!in_sched_functions(pc))
237 			return pc;
238 		fp = *(unsigned long *) fp;
239 	} while (count++ < 16);		/* ;dgt2;tmp */
240 	return 0;
241 }
242 
243 /*
244  * Do necessary setup to start up a newly executed thread.
245  * Will startup in user mode (status_extension = 0).
246  */
247 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
248 {
249 	memset((void *) regs, 0, sizeof(struct pt_regs));
250 	regs->estatus = ESTATUS_EPIE | ESTATUS_EU;
251 	regs->ea = pc;
252 	regs->sp = sp;
253 }
254 
255 asmlinkage int nios2_clone(unsigned long clone_flags, unsigned long newsp,
256 			   int __user *parent_tidptr, int __user *child_tidptr,
257 			   unsigned long tls)
258 {
259 	struct kernel_clone_args args = {
260 		.flags		= (lower_32_bits(clone_flags) & ~CSIGNAL),
261 		.pidfd		= parent_tidptr,
262 		.child_tid	= child_tidptr,
263 		.parent_tid	= parent_tidptr,
264 		.exit_signal	= (lower_32_bits(clone_flags) & CSIGNAL),
265 		.stack		= newsp,
266 		.tls		= tls,
267 	};
268 
269 	return kernel_clone(&args);
270 }
271