xref: /openbmc/linux/arch/nios2/kernel/process.c (revision d5e7cafd)
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/tick.h>
18 #include <linux/uaccess.h>
19 
20 #include <asm/unistd.h>
21 #include <asm/traps.h>
22 #include <asm/cpuinfo.h>
23 
24 asmlinkage void ret_from_fork(void);
25 asmlinkage void ret_from_kernel_thread(void);
26 
27 void (*pm_power_off)(void) = NULL;
28 EXPORT_SYMBOL(pm_power_off);
29 
30 void arch_cpu_idle(void)
31 {
32 	local_irq_enable();
33 }
34 
35 /*
36  * The development boards have no way to pull a board reset. Just jump to the
37  * cpu reset address and let the boot loader or the code in head.S take care of
38  * resetting peripherals.
39  */
40 void machine_restart(char *__unused)
41 {
42 	pr_notice("Machine restart (%08x)...\n", cpuinfo.reset_addr);
43 	local_irq_disable();
44 	__asm__ __volatile__ (
45 	"jmp	%0\n\t"
46 	:
47 	: "r" (cpuinfo.reset_addr)
48 	: "r4");
49 }
50 
51 void machine_halt(void)
52 {
53 	pr_notice("Machine halt...\n");
54 	local_irq_disable();
55 	for (;;)
56 		;
57 }
58 
59 /*
60  * There is no way to power off the development boards. So just spin for now. If
61  * we ever have a way of resetting a board using a GPIO we should add that here.
62  */
63 void machine_power_off(void)
64 {
65 	pr_notice("Machine power off...\n");
66 	local_irq_disable();
67 	for (;;)
68 		;
69 }
70 
71 void show_regs(struct pt_regs *regs)
72 {
73 	pr_notice("\n");
74 	show_regs_print_info(KERN_DEFAULT);
75 
76 	pr_notice("r1: %08lx r2: %08lx r3: %08lx r4: %08lx\n",
77 		regs->r1,  regs->r2,  regs->r3,  regs->r4);
78 
79 	pr_notice("r5: %08lx r6: %08lx r7: %08lx r8: %08lx\n",
80 		regs->r5,  regs->r6,  regs->r7,  regs->r8);
81 
82 	pr_notice("r9: %08lx r10: %08lx r11: %08lx r12: %08lx\n",
83 		regs->r9,  regs->r10, regs->r11, regs->r12);
84 
85 	pr_notice("r13: %08lx r14: %08lx r15: %08lx\n",
86 		regs->r13, regs->r14, regs->r15);
87 
88 	pr_notice("ra: %08lx fp:  %08lx sp: %08lx gp: %08lx\n",
89 		regs->ra,  regs->fp,  regs->sp,  regs->gp);
90 
91 	pr_notice("ea: %08lx estatus: %08lx\n",
92 		regs->ea,  regs->estatus);
93 }
94 
95 void flush_thread(void)
96 {
97 	set_fs(USER_DS);
98 }
99 
100 int copy_thread(unsigned long clone_flags,
101 		unsigned long usp, unsigned long arg, struct task_struct *p)
102 {
103 	struct pt_regs *childregs = task_pt_regs(p);
104 	struct pt_regs *regs;
105 	struct switch_stack *stack;
106 	struct switch_stack *childstack =
107 		((struct switch_stack *)childregs) - 1;
108 
109 	if (unlikely(p->flags & PF_KTHREAD)) {
110 		memset(childstack, 0,
111 			sizeof(struct switch_stack) + sizeof(struct pt_regs));
112 
113 		childstack->r16 = usp;		/* fn */
114 		childstack->r17 = arg;
115 		childstack->ra = (unsigned long) ret_from_kernel_thread;
116 		childregs->estatus = STATUS_PIE;
117 		childregs->sp = (unsigned long) childstack;
118 
119 		p->thread.ksp = (unsigned long) childstack;
120 		p->thread.kregs = childregs;
121 		return 0;
122 	}
123 
124 	regs = current_pt_regs();
125 	*childregs = *regs;
126 	childregs->r2 = 0;	/* Set the return value for the child. */
127 	childregs->r7 = 0;
128 
129 	stack = ((struct switch_stack *) regs) - 1;
130 	*childstack = *stack;
131 	childstack->ra = (unsigned long)ret_from_fork;
132 	p->thread.kregs = childregs;
133 	p->thread.ksp = (unsigned long) childstack;
134 
135 	if (usp)
136 		childregs->sp = usp;
137 
138 	/* Initialize tls register. */
139 	if (clone_flags & CLONE_SETTLS)
140 		childstack->r23 = regs->r8;
141 
142 	return 0;
143 }
144 
145 /*
146  *	Generic dumping code. Used for panic and debug.
147  */
148 void dump(struct pt_regs *fp)
149 {
150 	unsigned long	*sp;
151 	unsigned char	*tp;
152 	int		i;
153 
154 	pr_emerg("\nCURRENT PROCESS:\n\n");
155 	pr_emerg("COMM=%s PID=%d\n", current->comm, current->pid);
156 
157 	if (current->mm) {
158 		pr_emerg("TEXT=%08x-%08x DATA=%08x-%08x BSS=%08x-%08x\n",
159 			(int) current->mm->start_code,
160 			(int) current->mm->end_code,
161 			(int) current->mm->start_data,
162 			(int) current->mm->end_data,
163 			(int) current->mm->end_data,
164 			(int) current->mm->brk);
165 		pr_emerg("USER-STACK=%08x  KERNEL-STACK=%08x\n\n",
166 			(int) current->mm->start_stack,
167 			(int)(((unsigned long) current) + THREAD_SIZE));
168 	}
169 
170 	pr_emerg("PC: %08lx\n", fp->ea);
171 	pr_emerg("SR: %08lx    SP: %08lx\n",
172 		(long) fp->estatus, (long) fp);
173 
174 	pr_emerg("r1: %08lx    r2: %08lx    r3: %08lx\n",
175 		fp->r1, fp->r2, fp->r3);
176 
177 	pr_emerg("r4: %08lx    r5: %08lx    r6: %08lx    r7: %08lx\n",
178 		fp->r4, fp->r5, fp->r6, fp->r7);
179 	pr_emerg("r8: %08lx    r9: %08lx    r10: %08lx    r11: %08lx\n",
180 		fp->r8, fp->r9, fp->r10, fp->r11);
181 	pr_emerg("r12: %08lx  r13: %08lx    r14: %08lx    r15: %08lx\n",
182 		fp->r12, fp->r13, fp->r14, fp->r15);
183 	pr_emerg("or2: %08lx   ra: %08lx     fp: %08lx    sp: %08lx\n",
184 		fp->orig_r2, fp->ra, fp->fp, fp->sp);
185 	pr_emerg("\nUSP: %08x   TRAPFRAME: %08x\n",
186 		(unsigned int) fp->sp, (unsigned int) fp);
187 
188 	pr_emerg("\nCODE:");
189 	tp = ((unsigned char *) fp->ea) - 0x20;
190 	for (sp = (unsigned long *) tp, i = 0; (i < 0x40);  i += 4) {
191 		if ((i % 0x10) == 0)
192 			pr_emerg("\n%08x: ", (int) (tp + i));
193 		pr_emerg("%08x ", (int) *sp++);
194 	}
195 	pr_emerg("\n");
196 
197 	pr_emerg("\nKERNEL STACK:");
198 	tp = ((unsigned char *) fp) - 0x40;
199 	for (sp = (unsigned long *) tp, i = 0; (i < 0xc0); i += 4) {
200 		if ((i % 0x10) == 0)
201 			pr_emerg("\n%08x: ", (int) (tp + i));
202 		pr_emerg("%08x ", (int) *sp++);
203 	}
204 	pr_emerg("\n");
205 	pr_emerg("\n");
206 
207 	pr_emerg("\nUSER STACK:");
208 	tp = (unsigned char *) (fp->sp - 0x10);
209 	for (sp = (unsigned long *) tp, i = 0; (i < 0x80); i += 4) {
210 		if ((i % 0x10) == 0)
211 			pr_emerg("\n%08x: ", (int) (tp + i));
212 		pr_emerg("%08x ", (int) *sp++);
213 	}
214 	pr_emerg("\n\n");
215 }
216 
217 unsigned long get_wchan(struct task_struct *p)
218 {
219 	unsigned long fp, pc;
220 	unsigned long stack_page;
221 	int count = 0;
222 
223 	if (!p || p == current || p->state == TASK_RUNNING)
224 		return 0;
225 
226 	stack_page = (unsigned long)p;
227 	fp = ((struct switch_stack *)p->thread.ksp)->fp;	/* ;dgt2 */
228 	do {
229 		if (fp < stack_page+sizeof(struct task_struct) ||
230 			fp >= 8184+stack_page)	/* ;dgt2;tmp */
231 			return 0;
232 		pc = ((unsigned long *)fp)[1];
233 		if (!in_sched_functions(pc))
234 			return pc;
235 		fp = *(unsigned long *) fp;
236 	} while (count++ < 16);		/* ;dgt2;tmp */
237 	return 0;
238 }
239 
240 /*
241  * Do necessary setup to start up a newly executed thread.
242  * Will startup in user mode (status_extension = 0).
243  */
244 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
245 {
246 	memset((void *) regs, 0, sizeof(struct pt_regs));
247 	regs->estatus = ESTATUS_EPIE | ESTATUS_EU;
248 	regs->ea = pc;
249 	regs->sp = sp;
250 }
251 
252 #include <linux/elfcore.h>
253 
254 /* Fill in the FPU structure for a core dump. */
255 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
256 {
257 	return 0; /* Nios2 has no FPU and thus no FPU registers */
258 }
259