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 
arch_cpu_idle(void)34 void 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  */
machine_restart(char * __unused)43 void 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 
machine_halt(void)54 void 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  */
machine_power_off(void)66 void machine_power_off(void)
67 {
68 	pr_notice("Machine power off...\n");
69 	local_irq_disable();
70 	for (;;)
71 		;
72 }
73 
show_regs(struct pt_regs * regs)74 void 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 
flush_thread(void)98 void flush_thread(void)
99 {
100 }
101 
copy_thread(struct task_struct * p,const struct kernel_clone_args * args)102 int 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  */
dump(struct pt_regs * fp)152 void 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 
__get_wchan(struct task_struct * p)221 unsigned 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(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  */
start_thread(struct pt_regs * regs,unsigned long pc,unsigned long sp)245 void 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 
nios2_clone(unsigned long clone_flags,unsigned long newsp,int __user * parent_tidptr,int __user * child_tidptr,unsigned long tls)253 asmlinkage 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(&args);
268 }
269