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 | #include "process.h" |
42 | |
43 | asmlinkage void ret_from_fork(void); |
44 | asmlinkage void ret_from_kernel_thread(void); |
45 | |
46 | void arch_cpu_idle(void) |
47 | { |
48 | #if defined(MACH_ATARI_ONLY) |
49 | /* block out HSYNC on the atari (falcon) */ |
50 | __asm__("stop #0x2200" : : : "cc" ); |
51 | #else |
52 | __asm__("stop #0x2000" : : : "cc" ); |
53 | #endif |
54 | } |
55 | |
56 | void machine_restart(char * __unused) |
57 | { |
58 | if (mach_reset) |
59 | mach_reset(); |
60 | for (;;); |
61 | } |
62 | |
63 | void machine_halt(void) |
64 | { |
65 | if (mach_halt) |
66 | mach_halt(); |
67 | for (;;); |
68 | } |
69 | |
70 | void machine_power_off(void) |
71 | { |
72 | do_kernel_power_off(); |
73 | for (;;); |
74 | } |
75 | |
76 | void (*pm_power_off)(void); |
77 | EXPORT_SYMBOL(pm_power_off); |
78 | |
79 | void show_regs(struct pt_regs * regs) |
80 | { |
81 | pr_info("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n" , |
82 | regs->format, regs->vector, regs->pc, regs->sr, |
83 | print_tainted()); |
84 | pr_info("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n" , |
85 | regs->orig_d0, regs->d0, regs->a2, regs->a1); |
86 | pr_info("A0: %08lx D5: %08lx D4: %08lx\n" , regs->a0, regs->d5, |
87 | regs->d4); |
88 | pr_info("D3: %08lx D2: %08lx D1: %08lx\n" , regs->d3, regs->d2, |
89 | regs->d1); |
90 | if (!(regs->sr & PS_S)) |
91 | pr_info("USP: %08lx\n" , rdusp()); |
92 | } |
93 | |
94 | void flush_thread(void) |
95 | { |
96 | current->thread.fc = USER_DATA; |
97 | #ifdef CONFIG_FPU |
98 | if (!FPU_IS_EMU) { |
99 | unsigned long zero = 0; |
100 | asm volatile("frestore %0" : :"m" (zero)); |
101 | } |
102 | #endif |
103 | } |
104 | |
105 | /* |
106 | * Why not generic sys_clone, you ask? m68k passes all arguments on stack. |
107 | * And we need all registers saved, which means a bunch of stuff pushed |
108 | * on top of pt_regs, which means that sys_clone() arguments would be |
109 | * buried. We could, of course, copy them, but it's too costly for no |
110 | * good reason - generic clone() would have to copy them *again* for |
111 | * kernel_clone() anyway. So in this case it's actually better to pass pt_regs * |
112 | * and extract arguments for kernel_clone() from there. Eventually we might |
113 | * go for calling kernel_clone() directly from the wrapper, but only after we |
114 | * are finished with kernel_clone() prototype conversion. |
115 | */ |
116 | asmlinkage int m68k_clone(struct pt_regs *regs) |
117 | { |
118 | /* regs will be equal to current_pt_regs() */ |
119 | struct kernel_clone_args args = { |
120 | .flags = regs->d1 & ~CSIGNAL, |
121 | .pidfd = (int __user *)regs->d3, |
122 | .child_tid = (int __user *)regs->d4, |
123 | .parent_tid = (int __user *)regs->d3, |
124 | .exit_signal = regs->d1 & CSIGNAL, |
125 | .stack = regs->d2, |
126 | .tls = regs->d5, |
127 | }; |
128 | |
129 | return kernel_clone(kargs: &args); |
130 | } |
131 | |
132 | /* |
133 | * Because extra registers are saved on the stack after the sys_clone3() |
134 | * arguments, this C wrapper extracts them from pt_regs * and then calls the |
135 | * generic sys_clone3() implementation. |
136 | */ |
137 | asmlinkage int m68k_clone3(struct pt_regs *regs) |
138 | { |
139 | return sys_clone3((struct clone_args __user *)regs->d1, regs->d2); |
140 | } |
141 | |
142 | int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) |
143 | { |
144 | unsigned long clone_flags = args->flags; |
145 | unsigned long usp = args->stack; |
146 | unsigned long tls = args->tls; |
147 | struct fork_frame { |
148 | struct switch_stack sw; |
149 | struct pt_regs regs; |
150 | } *frame; |
151 | |
152 | frame = (struct fork_frame *) (task_stack_page(task: p) + THREAD_SIZE) - 1; |
153 | |
154 | p->thread.ksp = (unsigned long)frame; |
155 | p->thread.esp0 = (unsigned long)&frame->regs; |
156 | |
157 | /* |
158 | * Must save the current SFC/DFC value, NOT the value when |
159 | * the parent was last descheduled - RGH 10-08-96 |
160 | */ |
161 | p->thread.fc = USER_DATA; |
162 | |
163 | if (unlikely(args->fn)) { |
164 | /* kernel thread */ |
165 | memset(frame, 0, sizeof(struct fork_frame)); |
166 | frame->regs.sr = PS_S; |
167 | frame->sw.a3 = (unsigned long)args->fn; |
168 | frame->sw.d7 = (unsigned long)args->fn_arg; |
169 | frame->sw.retpc = (unsigned long)ret_from_kernel_thread; |
170 | p->thread.usp = 0; |
171 | return 0; |
172 | } |
173 | memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs), |
174 | sizeof(struct fork_frame)); |
175 | frame->regs.d0 = 0; |
176 | frame->sw.retpc = (unsigned long)ret_from_fork; |
177 | p->thread.usp = usp ?: rdusp(); |
178 | |
179 | if (clone_flags & CLONE_SETTLS) |
180 | task_thread_info(p)->tp_value = tls; |
181 | |
182 | #ifdef CONFIG_FPU |
183 | if (!FPU_IS_EMU) { |
184 | /* Copy the current fpu state */ |
185 | asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory" ); |
186 | |
187 | if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) { |
188 | if (CPU_IS_COLDFIRE) { |
189 | asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t" |
190 | "fmovel %/fpiar,%1\n\t" |
191 | "fmovel %/fpcr,%2\n\t" |
192 | "fmovel %/fpsr,%3" |
193 | : |
194 | : "m" (p->thread.fp[0]), |
195 | "m" (p->thread.fpcntl[0]), |
196 | "m" (p->thread.fpcntl[1]), |
197 | "m" (p->thread.fpcntl[2]) |
198 | : "memory" ); |
199 | } else { |
200 | asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" |
201 | "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" |
202 | : |
203 | : "m" (p->thread.fp[0]), |
204 | "m" (p->thread.fpcntl[0]) |
205 | : "memory" ); |
206 | } |
207 | } |
208 | |
209 | /* Restore the state in case the fpu was busy */ |
210 | asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); |
211 | } |
212 | #endif /* CONFIG_FPU */ |
213 | |
214 | return 0; |
215 | } |
216 | |
217 | /* Fill in the fpu structure for a core dump. */ |
218 | int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu) |
219 | { |
220 | if (FPU_IS_EMU) { |
221 | int i; |
222 | |
223 | memcpy(fpu->fpcntl, current->thread.fpcntl, 12); |
224 | memcpy(fpu->fpregs, current->thread.fp, 96); |
225 | /* Convert internal fpu reg representation |
226 | * into long double format |
227 | */ |
228 | for (i = 0; i < 24; i += 3) |
229 | fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | |
230 | ((fpu->fpregs[i] & 0x0000ffff) << 16); |
231 | return 1; |
232 | } |
233 | |
234 | if (IS_ENABLED(CONFIG_FPU)) { |
235 | char fpustate[216]; |
236 | |
237 | /* First dump the fpu context to avoid protocol violation. */ |
238 | asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory" ); |
239 | if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) |
240 | return 0; |
241 | |
242 | if (CPU_IS_COLDFIRE) { |
243 | asm volatile ("fmovel %/fpiar,%0\n\t" |
244 | "fmovel %/fpcr,%1\n\t" |
245 | "fmovel %/fpsr,%2\n\t" |
246 | "fmovemd %/fp0-%/fp7,%3" |
247 | : |
248 | : "m" (fpu->fpcntl[0]), |
249 | "m" (fpu->fpcntl[1]), |
250 | "m" (fpu->fpcntl[2]), |
251 | "m" (fpu->fpregs[0]) |
252 | : "memory" ); |
253 | } else { |
254 | asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" |
255 | : |
256 | : "m" (fpu->fpcntl[0]) |
257 | : "memory" ); |
258 | asm volatile ("fmovemx %/fp0-%/fp7,%0" |
259 | : |
260 | : "m" (fpu->fpregs[0]) |
261 | : "memory" ); |
262 | } |
263 | } |
264 | |
265 | return 1; |
266 | } |
267 | |
268 | unsigned long __get_wchan(struct task_struct *p) |
269 | { |
270 | unsigned long fp, pc; |
271 | unsigned long stack_page; |
272 | int count = 0; |
273 | |
274 | stack_page = (unsigned long)task_stack_page(task: p); |
275 | fp = ((struct switch_stack *)p->thread.ksp)->a6; |
276 | do { |
277 | if (fp < stack_page+sizeof(struct thread_info) || |
278 | fp >= 8184+stack_page) |
279 | return 0; |
280 | pc = ((unsigned long *)fp)[1]; |
281 | if (!in_sched_functions(addr: pc)) |
282 | return pc; |
283 | fp = *(unsigned long *) fp; |
284 | } while (count++ < 16); |
285 | return 0; |
286 | } |
287 | |