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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
34#include <linux/uaccess.h>
35#include <asm/traps.h>
36#include <asm/machdep.h>
37#include <asm/setup.h>
38#include <asm/pgtable.h>
39
40
41asmlinkage void ret_from_fork(void);
42asmlinkage void ret_from_kernel_thread(void);
43
44void arch_cpu_idle(void)
45{
46#if defined(MACH_ATARI_ONLY)
47 /* block out HSYNC on the atari (falcon) */
48 __asm__("stop #0x2200" : : : "cc");
49#else
50 __asm__("stop #0x2000" : : : "cc");
51#endif
52}
53
54void machine_restart(char * __unused)
55{
56 if (mach_reset)
57 mach_reset();
58 for (;;);
59}
60
61void machine_halt(void)
62{
63 if (mach_halt)
64 mach_halt();
65 for (;;);
66}
67
68void machine_power_off(void)
69{
70 if (mach_power_off)
71 mach_power_off();
72 for (;;);
73}
74
75void (*pm_power_off)(void) = machine_power_off;
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.fs = __USER_DS;
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 * do_fork() anyway. So in this case it's actually better to pass pt_regs *
111 * and extract arguments for do_fork() from there. Eventually we might
112 * go for calling do_fork() directly from the wrapper, but only after we
113 * are finished with do_fork() prototype conversion.
114 */
115asmlinkage int m68k_clone(struct pt_regs *regs)
116{
117 /* regs will be equal to current_pt_regs() */
118 return do_fork(regs->d1, regs->d2, 0,
119 (int __user *)regs->d3, (int __user *)regs->d4);
120}
121
122int copy_thread(unsigned long clone_flags, unsigned long usp,
123 unsigned long arg, struct task_struct *p)
124{
125 struct fork_frame {
126 struct switch_stack sw;
127 struct pt_regs regs;
128 } *frame;
129
130 frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
131
132 p->thread.ksp = (unsigned long)frame;
133 p->thread.esp0 = (unsigned long)&frame->regs;
134
135 /*
136 * Must save the current SFC/DFC value, NOT the value when
137 * the parent was last descheduled - RGH 10-08-96
138 */
139 p->thread.fs = get_fs().seg;
140
141 if (unlikely(p->flags & PF_KTHREAD)) {
142 /* kernel thread */
143 memset(frame, 0, sizeof(struct fork_frame));
144 frame->regs.sr = PS_S;
145 frame->sw.a3 = usp; /* function */
146 frame->sw.d7 = arg;
147 frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
148 p->thread.usp = 0;
149 return 0;
150 }
151 memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
152 sizeof(struct fork_frame));
153 frame->regs.d0 = 0;
154 frame->sw.retpc = (unsigned long)ret_from_fork;
155 p->thread.usp = usp ?: rdusp();
156
157 if (clone_flags & CLONE_SETTLS)
158 task_thread_info(p)->tp_value = frame->regs.d5;
159
160#ifdef CONFIG_FPU
161 if (!FPU_IS_EMU) {
162 /* Copy the current fpu state */
163 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
164
165 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
166 if (CPU_IS_COLDFIRE) {
167 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
168 "fmovel %/fpiar,%1\n\t"
169 "fmovel %/fpcr,%2\n\t"
170 "fmovel %/fpsr,%3"
171 :
172 : "m" (p->thread.fp[0]),
173 "m" (p->thread.fpcntl[0]),
174 "m" (p->thread.fpcntl[1]),
175 "m" (p->thread.fpcntl[2])
176 : "memory");
177 } else {
178 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
179 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
180 :
181 : "m" (p->thread.fp[0]),
182 "m" (p->thread.fpcntl[0])
183 : "memory");
184 }
185 }
186
187 /* Restore the state in case the fpu was busy */
188 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
189 }
190#endif /* CONFIG_FPU */
191
192 return 0;
193}
194
195/* Fill in the fpu structure for a core dump. */
196int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
197{
198 if (FPU_IS_EMU) {
199 int i;
200
201 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
202 memcpy(fpu->fpregs, current->thread.fp, 96);
203 /* Convert internal fpu reg representation
204 * into long double format
205 */
206 for (i = 0; i < 24; i += 3)
207 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
208 ((fpu->fpregs[i] & 0x0000ffff) << 16);
209 return 1;
210 }
211
212 if (IS_ENABLED(CONFIG_FPU)) {
213 char fpustate[216];
214
215 /* First dump the fpu context to avoid protocol violation. */
216 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
217 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
218 return 0;
219
220 if (CPU_IS_COLDFIRE) {
221 asm volatile ("fmovel %/fpiar,%0\n\t"
222 "fmovel %/fpcr,%1\n\t"
223 "fmovel %/fpsr,%2\n\t"
224 "fmovemd %/fp0-%/fp7,%3"
225 :
226 : "m" (fpu->fpcntl[0]),
227 "m" (fpu->fpcntl[1]),
228 "m" (fpu->fpcntl[2]),
229 "m" (fpu->fpregs[0])
230 : "memory");
231 } else {
232 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
233 :
234 : "m" (fpu->fpcntl[0])
235 : "memory");
236 asm volatile ("fmovemx %/fp0-%/fp7,%0"
237 :
238 : "m" (fpu->fpregs[0])
239 : "memory");
240 }
241 }
242
243 return 1;
244}
245EXPORT_SYMBOL(dump_fpu);
246
247unsigned long get_wchan(struct task_struct *p)
248{
249 unsigned long fp, pc;
250 unsigned long stack_page;
251 int count = 0;
252 if (!p || p == current || p->state == TASK_RUNNING)
253 return 0;
254
255 stack_page = (unsigned long)task_stack_page(p);
256 fp = ((struct switch_stack *)p->thread.ksp)->a6;
257 do {
258 if (fp < stack_page+sizeof(struct thread_info) ||
259 fp >= 8184+stack_page)
260 return 0;
261 pc = ((unsigned long *)fp)[1];
262 if (!in_sched_functions(pc))
263 return pc;
264 fp = *(unsigned long *) fp;
265 } while (count++ < 16);
266 return 0;
267}
1/*
2 * linux/arch/m68k/kernel/process.c
3 *
4 * Copyright (C) 1995 Hamish Macdonald
5 *
6 * 68060 fixes by Jesper Skov
7 */
8
9/*
10 * This file handles the architecture-dependent parts of process handling..
11 */
12
13#include <linux/errno.h>
14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
18#include <linux/slab.h>
19#include <linux/fs.h>
20#include <linux/smp.h>
21#include <linux/stddef.h>
22#include <linux/unistd.h>
23#include <linux/ptrace.h>
24#include <linux/user.h>
25#include <linux/reboot.h>
26#include <linux/init_task.h>
27#include <linux/mqueue.h>
28
29#include <asm/uaccess.h>
30#include <asm/traps.h>
31#include <asm/machdep.h>
32#include <asm/setup.h>
33#include <asm/pgtable.h>
34
35
36asmlinkage void ret_from_fork(void);
37
38
39/*
40 * Return saved PC from a blocked thread
41 */
42unsigned long thread_saved_pc(struct task_struct *tsk)
43{
44 struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp;
45 /* Check whether the thread is blocked in resume() */
46 if (in_sched_functions(sw->retpc))
47 return ((unsigned long *)sw->a6)[1];
48 else
49 return sw->retpc;
50}
51
52/*
53 * The idle loop on an m68k..
54 */
55static void default_idle(void)
56{
57 if (!need_resched())
58#if defined(MACH_ATARI_ONLY)
59 /* block out HSYNC on the atari (falcon) */
60 __asm__("stop #0x2200" : : : "cc");
61#else
62 __asm__("stop #0x2000" : : : "cc");
63#endif
64}
65
66void (*idle)(void) = default_idle;
67
68/*
69 * The idle thread. There's no useful work to be
70 * done, so just try to conserve power and have a
71 * low exit latency (ie sit in a loop waiting for
72 * somebody to say that they'd like to reschedule)
73 */
74void cpu_idle(void)
75{
76 /* endless idle loop with no priority at all */
77 while (1) {
78 while (!need_resched())
79 idle();
80 schedule_preempt_disabled();
81 }
82}
83
84void machine_restart(char * __unused)
85{
86 if (mach_reset)
87 mach_reset();
88 for (;;);
89}
90
91void machine_halt(void)
92{
93 if (mach_halt)
94 mach_halt();
95 for (;;);
96}
97
98void machine_power_off(void)
99{
100 if (mach_power_off)
101 mach_power_off();
102 for (;;);
103}
104
105void (*pm_power_off)(void) = machine_power_off;
106EXPORT_SYMBOL(pm_power_off);
107
108void show_regs(struct pt_regs * regs)
109{
110 printk("\n");
111 printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n",
112 regs->format, regs->vector, regs->pc, regs->sr, print_tainted());
113 printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n",
114 regs->orig_d0, regs->d0, regs->a2, regs->a1);
115 printk("A0: %08lx D5: %08lx D4: %08lx\n",
116 regs->a0, regs->d5, regs->d4);
117 printk("D3: %08lx D2: %08lx D1: %08lx\n",
118 regs->d3, regs->d2, regs->d1);
119 if (!(regs->sr & PS_S))
120 printk("USP: %08lx\n", rdusp());
121}
122
123/*
124 * Create a kernel thread
125 */
126int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
127{
128 int pid;
129 mm_segment_t fs;
130
131 fs = get_fs();
132 set_fs (KERNEL_DS);
133
134 {
135 register long retval __asm__ ("d0");
136 register long clone_arg __asm__ ("d1") = flags | CLONE_VM | CLONE_UNTRACED;
137
138 retval = __NR_clone;
139 __asm__ __volatile__
140 ("clrl %%d2\n\t"
141 "trap #0\n\t" /* Linux/m68k system call */
142 "tstl %0\n\t" /* child or parent */
143 "jne 1f\n\t" /* parent - jump */
144#ifdef CONFIG_MMU
145 "lea %%sp@(%c7),%6\n\t" /* reload current */
146 "movel %6@,%6\n\t"
147#endif
148 "movel %3,%%sp@-\n\t" /* push argument */
149 "jsr %4@\n\t" /* call fn */
150 "movel %0,%%d1\n\t" /* pass exit value */
151 "movel %2,%%d0\n\t" /* exit */
152 "trap #0\n"
153 "1:"
154 : "+d" (retval)
155 : "i" (__NR_clone), "i" (__NR_exit),
156 "r" (arg), "a" (fn), "d" (clone_arg), "r" (current),
157 "i" (-THREAD_SIZE)
158 : "d2");
159
160 pid = retval;
161 }
162
163 set_fs (fs);
164 return pid;
165}
166EXPORT_SYMBOL(kernel_thread);
167
168void flush_thread(void)
169{
170 current->thread.fs = __USER_DS;
171#ifdef CONFIG_FPU
172 if (!FPU_IS_EMU) {
173 unsigned long zero = 0;
174 asm volatile("frestore %0": :"m" (zero));
175 }
176#endif
177}
178
179/*
180 * "m68k_fork()".. By the time we get here, the
181 * non-volatile registers have also been saved on the
182 * stack. We do some ugly pointer stuff here.. (see
183 * also copy_thread)
184 */
185
186asmlinkage int m68k_fork(struct pt_regs *regs)
187{
188#ifdef CONFIG_MMU
189 return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
190#else
191 return -EINVAL;
192#endif
193}
194
195asmlinkage int m68k_vfork(struct pt_regs *regs)
196{
197 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
198 NULL, NULL);
199}
200
201asmlinkage int m68k_clone(struct pt_regs *regs)
202{
203 unsigned long clone_flags;
204 unsigned long newsp;
205 int __user *parent_tidptr, *child_tidptr;
206
207 /* syscall2 puts clone_flags in d1 and usp in d2 */
208 clone_flags = regs->d1;
209 newsp = regs->d2;
210 parent_tidptr = (int __user *)regs->d3;
211 child_tidptr = (int __user *)regs->d4;
212 if (!newsp)
213 newsp = rdusp();
214 return do_fork(clone_flags, newsp, regs, 0,
215 parent_tidptr, child_tidptr);
216}
217
218int copy_thread(unsigned long clone_flags, unsigned long usp,
219 unsigned long unused,
220 struct task_struct * p, struct pt_regs * regs)
221{
222 struct pt_regs * childregs;
223 struct switch_stack * childstack, *stack;
224 unsigned long *retp;
225
226 childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
227
228 *childregs = *regs;
229 childregs->d0 = 0;
230
231 retp = ((unsigned long *) regs);
232 stack = ((struct switch_stack *) retp) - 1;
233
234 childstack = ((struct switch_stack *) childregs) - 1;
235 *childstack = *stack;
236 childstack->retpc = (unsigned long)ret_from_fork;
237
238 p->thread.usp = usp;
239 p->thread.ksp = (unsigned long)childstack;
240
241 if (clone_flags & CLONE_SETTLS)
242 task_thread_info(p)->tp_value = regs->d5;
243
244 /*
245 * Must save the current SFC/DFC value, NOT the value when
246 * the parent was last descheduled - RGH 10-08-96
247 */
248 p->thread.fs = get_fs().seg;
249
250#ifdef CONFIG_FPU
251 if (!FPU_IS_EMU) {
252 /* Copy the current fpu state */
253 asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory");
254
255 if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) {
256 if (CPU_IS_COLDFIRE) {
257 asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t"
258 "fmovel %/fpiar,%1\n\t"
259 "fmovel %/fpcr,%2\n\t"
260 "fmovel %/fpsr,%3"
261 :
262 : "m" (p->thread.fp[0]),
263 "m" (p->thread.fpcntl[0]),
264 "m" (p->thread.fpcntl[1]),
265 "m" (p->thread.fpcntl[2])
266 : "memory");
267 } else {
268 asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t"
269 "fmoveml %/fpiar/%/fpcr/%/fpsr,%1"
270 :
271 : "m" (p->thread.fp[0]),
272 "m" (p->thread.fpcntl[0])
273 : "memory");
274 }
275 }
276
277 /* Restore the state in case the fpu was busy */
278 asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0]));
279 }
280#endif /* CONFIG_FPU */
281
282 return 0;
283}
284
285/* Fill in the fpu structure for a core dump. */
286#ifdef CONFIG_FPU
287int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
288{
289 char fpustate[216];
290
291 if (FPU_IS_EMU) {
292 int i;
293
294 memcpy(fpu->fpcntl, current->thread.fpcntl, 12);
295 memcpy(fpu->fpregs, current->thread.fp, 96);
296 /* Convert internal fpu reg representation
297 * into long double format
298 */
299 for (i = 0; i < 24; i += 3)
300 fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) |
301 ((fpu->fpregs[i] & 0x0000ffff) << 16);
302 return 1;
303 }
304
305 /* First dump the fpu context to avoid protocol violation. */
306 asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory");
307 if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2])
308 return 0;
309
310 if (CPU_IS_COLDFIRE) {
311 asm volatile ("fmovel %/fpiar,%0\n\t"
312 "fmovel %/fpcr,%1\n\t"
313 "fmovel %/fpsr,%2\n\t"
314 "fmovemd %/fp0-%/fp7,%3"
315 :
316 : "m" (fpu->fpcntl[0]),
317 "m" (fpu->fpcntl[1]),
318 "m" (fpu->fpcntl[2]),
319 "m" (fpu->fpregs[0])
320 : "memory");
321 } else {
322 asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0"
323 :
324 : "m" (fpu->fpcntl[0])
325 : "memory");
326 asm volatile ("fmovemx %/fp0-%/fp7,%0"
327 :
328 : "m" (fpu->fpregs[0])
329 : "memory");
330 }
331
332 return 1;
333}
334EXPORT_SYMBOL(dump_fpu);
335#endif /* CONFIG_FPU */
336
337/*
338 * sys_execve() executes a new program.
339 */
340asmlinkage int sys_execve(const char __user *name,
341 const char __user *const __user *argv,
342 const char __user *const __user *envp)
343{
344 int error;
345 char * filename;
346 struct pt_regs *regs = (struct pt_regs *) &name;
347
348 filename = getname(name);
349 error = PTR_ERR(filename);
350 if (IS_ERR(filename))
351 return error;
352 error = do_execve(filename, argv, envp, regs);
353 putname(filename);
354 return error;
355}
356
357unsigned long get_wchan(struct task_struct *p)
358{
359 unsigned long fp, pc;
360 unsigned long stack_page;
361 int count = 0;
362 if (!p || p == current || p->state == TASK_RUNNING)
363 return 0;
364
365 stack_page = (unsigned long)task_stack_page(p);
366 fp = ((struct switch_stack *)p->thread.ksp)->a6;
367 do {
368 if (fp < stack_page+sizeof(struct thread_info) ||
369 fp >= 8184+stack_page)
370 return 0;
371 pc = ((unsigned long *)fp)[1];
372 if (!in_sched_functions(pc))
373 return pc;
374 fp = *(unsigned long *) fp;
375 } while (count++ < 16);
376 return 0;
377}