Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/arch/m68k/kernel/process.c
4 *
5 * Copyright (C) 1995 Hamish Macdonald
6 *
7 * 68060 fixes by Jesper Skov
8 */
9
10/*
11 * This file handles the architecture-dependent parts of process handling..
12 */
13
14#include <linux/errno.h>
15#include <linux/module.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/kernel.h>
21#include <linux/mm.h>
22#include <linux/slab.h>
23#include <linux/fs.h>
24#include <linux/smp.h>
25#include <linux/stddef.h>
26#include <linux/unistd.h>
27#include <linux/ptrace.h>
28#include <linux/user.h>
29#include <linux/reboot.h>
30#include <linux/init_task.h>
31#include <linux/mqueue.h>
32#include <linux/rcupdate.h>
33#include <linux/syscalls.h>
34#include <linux/uaccess.h>
35#include <linux/elfcore.h>
36
37#include <asm/traps.h>
38#include <asm/machdep.h>
39#include <asm/setup.h>
40
41
42asmlinkage void ret_from_fork(void);
43asmlinkage void ret_from_kernel_thread(void);
44
45void arch_cpu_idle(void)
46{
47#if defined(MACH_ATARI_ONLY)
48 /* block out HSYNC on the atari (falcon) */
49 __asm__("stop #0x2200" : : : "cc");
50#else
51 __asm__("stop #0x2000" : : : "cc");
52#endif
53}
54
55void machine_restart(char * __unused)
56{
57 if (mach_reset)
58 mach_reset();
59 for (;;);
60}
61
62void machine_halt(void)
63{
64 if (mach_halt)
65 mach_halt();
66 for (;;);
67}
68
69void machine_power_off(void)
70{
71 do_kernel_power_off();
72 for (;;);
73}
74
75void (*pm_power_off)(void);
76EXPORT_SYMBOL(pm_power_off);
77
78void show_regs(struct pt_regs * regs)
79{
80 pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
81 regs->format, regs->vector, regs->pc, regs->sr,
82 print_tainted());
83 pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
84 regs->orig_d0, regs->d0, regs->a2, regs->a1);
85 pr_info("A0: %08lx D5: %08lx D4: %08lx\n", regs->a0, regs->d5,
86 regs->d4);
87 pr_info("D3: %08lx D2: %08lx D1: %08lx\n", regs->d3, regs->d2,
88 regs->d1);
89 if (!(regs->sr & PS_S))
90 pr_info("USP: %08lx\n", rdusp());
91}
92
93void flush_thread(void)
94{
95 current->thread.fc = USER_DATA;
96#ifdef CONFIG_FPU
97 if (!FPU_IS_EMU) {
98 unsigned long zero = 0;
99 asm volatile("frestore %0": :"m" (zero));
100 }
101#endif
102}
103
104/*
105 * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
106 * And we need all registers saved, which means a bunch of stuff pushed
107 * on top of pt_regs, which means that sys_clone() arguments would be
108 * buried. We could, of course, copy them, but it's too costly for no
109 * good reason - generic clone() would have to copy them *again* for
110 * kernel_clone() anyway. So in this case it's actually better to pass pt_regs *
111 * and extract arguments for kernel_clone() from there. Eventually we might
112 * go for calling kernel_clone() directly from the wrapper, but only after we
113 * are finished with kernel_clone() prototype conversion.
114 */
115asmlinkage int m68k_clone(struct pt_regs *regs)
116{
117 /* regs will be equal to current_pt_regs() */
118 struct kernel_clone_args args = {
119 .flags = regs->d1 & ~CSIGNAL,
120 .pidfd = (int __user *)regs->d3,
121 .child_tid = (int __user *)regs->d4,
122 .parent_tid = (int __user *)regs->d3,
123 .exit_signal = regs->d1 & CSIGNAL,
124 .stack = regs->d2,
125 .tls = regs->d5,
126 };
127
128 return kernel_clone(&args);
129}
130
131/*
132 * Because extra registers are saved on the stack after the sys_clone3()
133 * arguments, this C wrapper extracts them from pt_regs * and then calls the
134 * generic sys_clone3() implementation.
135 */
136asmlinkage int m68k_clone3(struct pt_regs *regs)
137{
138 return sys_clone3((struct clone_args __user *)regs->d1, regs->d2);
139}
140
141int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
142{
143 unsigned long clone_flags = args->flags;
144 unsigned long usp = args->stack;
145 unsigned long tls = args->tls;
146 struct fork_frame {
147 struct switch_stack sw;
148 struct pt_regs regs;
149 } *frame;
150
151 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
152
153 p->thread.ksp = (unsigned long)frame;
154 p->thread.esp0 = (unsigned long)&frame->regs;
155
156 /*
157 * Must save the current SFC/DFC value, NOT the value when
158 * the parent was last descheduled - RGH 10-08-96
159 */
160 p->thread.fc = USER_DATA;
161
162 if (unlikely(args->fn)) {
163 /* kernel thread */
164 memset(frame, 0, sizeof(struct fork_frame));
165 frame->regs.sr = PS_S;
166 frame->sw.a3 = (unsigned long)args->fn;
167 frame->sw.d7 = (unsigned long)args->fn_arg;
168 frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
169 p->thread.usp = 0;
170 return 0;
171 }
172 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
173 sizeof(struct fork_frame));
174 frame->regs.d0 = 0;
175 frame->sw.retpc = (unsigned long)ret_from_fork;
176 p->thread.usp = usp ?: rdusp();
177
178 if (clone_flags & CLONE_SETTLS)
179 task_thread_info(p)->tp_value = tls;
180
181#ifdef CONFIG_FPU
182 if (!FPU_IS_EMU) {
183 /* Copy the current fpu state */
184 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
185
186 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
187 if (CPU_IS_COLDFIRE) {
188 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
189 "fmovel %/fpiar,%1\n\t"
190 "fmovel %/fpcr,%2\n\t"
191 "fmovel %/fpsr,%3"
192 :
193 : "m" (p->thread.fp[0]),
194 "m" (p->thread.fpcntl[0]),
195 "m" (p->thread.fpcntl[1]),
196 "m" (p->thread.fpcntl[2])
197 : "memory");
198 } else {
199 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
200 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
201 :
202 : "m" (p->thread.fp[0]),
203 "m" (p->thread.fpcntl[0])
204 : "memory");
205 }
206 }
207
208 /* Restore the state in case the fpu was busy */
209 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
210 }
211#endif /* CONFIG_FPU */
212
213 return 0;
214}
215
216/* Fill in the fpu structure for a core dump. */
217int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
218{
219 if (FPU_IS_EMU) {
220 int i;
221
222 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
223 memcpy(fpu->fpregs, current->thread.fp, 96);
224 /* Convert internal fpu reg representation
225 * into long double format
226 */
227 for (i = 0; i < 24; i += 3)
228 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
229 ((fpu->fpregs[i] & 0x0000ffff) << 16);
230 return 1;
231 }
232
233 if (IS_ENABLED(CONFIG_FPU)) {
234 char fpustate[216];
235
236 /* First dump the fpu context to avoid protocol violation. */
237 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
238 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
239 return 0;
240
241 if (CPU_IS_COLDFIRE) {
242 asm volatile ("fmovel %/fpiar,%0\n\t"
243 "fmovel %/fpcr,%1\n\t"
244 "fmovel %/fpsr,%2\n\t"
245 "fmovemd %/fp0-%/fp7,%3"
246 :
247 : "m" (fpu->fpcntl[0]),
248 "m" (fpu->fpcntl[1]),
249 "m" (fpu->fpcntl[2]),
250 "m" (fpu->fpregs[0])
251 : "memory");
252 } else {
253 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
254 :
255 : "m" (fpu->fpcntl[0])
256 : "memory");
257 asm volatile ("fmovemx %/fp0-%/fp7,%0"
258 :
259 : "m" (fpu->fpregs[0])
260 : "memory");
261 }
262 }
263
264 return 1;
265}
266
267unsigned long __get_wchan(struct task_struct *p)
268{
269 unsigned long fp, pc;
270 unsigned long stack_page;
271 int count = 0;
272
273 stack_page = (unsigned long)task_stack_page(p);
274 fp = ((struct switch_stack *)p->thread.ksp)->a6;
275 do {
276 if (fp < stack_page+sizeof(struct thread_info) ||
277 fp >= 8184+stack_page)
278 return 0;
279 pc = ((unsigned long *)fp)[1];
280 if (!in_sched_functions(pc))
281 return pc;
282 fp = *(unsigned long *) fp;
283 } while (count++ < 16);
284 return 0;
285}
1#ifdef CONFIG_MMU
2#include "process_mm.c"
3#else
4#include "process_no.c"
5#endif