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fde39441 GU |
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> | |
5b57ba37 | 28 | #include <linux/rcupdate.h> |
fde39441 GU |
29 | |
30 | #include <asm/uaccess.h> | |
fde39441 GU |
31 | #include <asm/traps.h> |
32 | #include <asm/machdep.h> | |
33 | #include <asm/setup.h> | |
34 | #include <asm/pgtable.h> | |
35 | ||
36 | ||
37 | asmlinkage void ret_from_fork(void); | |
533e6903 | 38 | asmlinkage void ret_from_kernel_thread(void); |
fde39441 GU |
39 | |
40 | ||
41 | /* | |
42 | * Return saved PC from a blocked thread | |
43 | */ | |
44 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
45 | { | |
46 | struct switch_stack *sw = (struct switch_stack *)tsk->thread.ksp; | |
47 | /* Check whether the thread is blocked in resume() */ | |
48 | if (in_sched_functions(sw->retpc)) | |
49 | return ((unsigned long *)sw->a6)[1]; | |
50 | else | |
51 | return sw->retpc; | |
52 | } | |
53 | ||
54 | /* | |
55 | * The idle loop on an m68k.. | |
56 | */ | |
57 | static void default_idle(void) | |
58 | { | |
59 | if (!need_resched()) | |
60 | #if defined(MACH_ATARI_ONLY) | |
61 | /* block out HSYNC on the atari (falcon) */ | |
62 | __asm__("stop #0x2200" : : : "cc"); | |
63 | #else | |
64 | __asm__("stop #0x2000" : : : "cc"); | |
65 | #endif | |
66 | } | |
67 | ||
68 | void (*idle)(void) = default_idle; | |
69 | ||
70 | /* | |
71 | * The idle thread. There's no useful work to be | |
72 | * done, so just try to conserve power and have a | |
73 | * low exit latency (ie sit in a loop waiting for | |
74 | * somebody to say that they'd like to reschedule) | |
75 | */ | |
76 | void cpu_idle(void) | |
77 | { | |
78 | /* endless idle loop with no priority at all */ | |
79 | while (1) { | |
5b57ba37 | 80 | rcu_idle_enter(); |
fde39441 GU |
81 | while (!need_resched()) |
82 | idle(); | |
5b57ba37 | 83 | rcu_idle_exit(); |
b57cb723 | 84 | schedule_preempt_disabled(); |
fde39441 GU |
85 | } |
86 | } | |
87 | ||
88 | void machine_restart(char * __unused) | |
89 | { | |
90 | if (mach_reset) | |
91 | mach_reset(); | |
92 | for (;;); | |
93 | } | |
94 | ||
95 | void machine_halt(void) | |
96 | { | |
97 | if (mach_halt) | |
98 | mach_halt(); | |
99 | for (;;); | |
100 | } | |
101 | ||
102 | void machine_power_off(void) | |
103 | { | |
104 | if (mach_power_off) | |
105 | mach_power_off(); | |
106 | for (;;); | |
107 | } | |
108 | ||
109 | void (*pm_power_off)(void) = machine_power_off; | |
110 | EXPORT_SYMBOL(pm_power_off); | |
111 | ||
112 | void show_regs(struct pt_regs * regs) | |
113 | { | |
114 | printk("\n"); | |
115 | printk("Format %02x Vector: %04x PC: %08lx Status: %04x %s\n", | |
116 | regs->format, regs->vector, regs->pc, regs->sr, print_tainted()); | |
117 | printk("ORIG_D0: %08lx D0: %08lx A2: %08lx A1: %08lx\n", | |
118 | regs->orig_d0, regs->d0, regs->a2, regs->a1); | |
119 | printk("A0: %08lx D5: %08lx D4: %08lx\n", | |
120 | regs->a0, regs->d5, regs->d4); | |
121 | printk("D3: %08lx D2: %08lx D1: %08lx\n", | |
122 | regs->d3, regs->d2, regs->d1); | |
123 | if (!(regs->sr & PS_S)) | |
124 | printk("USP: %08lx\n", rdusp()); | |
125 | } | |
126 | ||
fde39441 GU |
127 | void flush_thread(void) |
128 | { | |
129 | current->thread.fs = __USER_DS; | |
130 | #ifdef CONFIG_FPU | |
131 | if (!FPU_IS_EMU) { | |
132 | unsigned long zero = 0; | |
133 | asm volatile("frestore %0": :"m" (zero)); | |
134 | } | |
135 | #endif | |
136 | } | |
137 | ||
138 | /* | |
20ecc91c AV |
139 | * Why not generic sys_clone, you ask? m68k passes all arguments on stack. |
140 | * And we need all registers saved, which means a bunch of stuff pushed | |
141 | * on top of pt_regs, which means that sys_clone() arguments would be | |
142 | * buried. We could, of course, copy them, but it's too costly for no | |
143 | * good reason - generic clone() would have to copy them *again* for | |
144 | * do_fork() anyway. So in this case it's actually better to pass pt_regs * | |
145 | * and extract arguments for do_fork() from there. Eventually we might | |
146 | * go for calling do_fork() directly from the wrapper, but only after we | |
147 | * are finished with do_fork() prototype conversion. | |
fde39441 | 148 | */ |
fde39441 GU |
149 | asmlinkage int m68k_clone(struct pt_regs *regs) |
150 | { | |
20ecc91c AV |
151 | /* regs will be equal to current_pt_regs() */ |
152 | return do_fork(regs->d1, regs->d2, regs, 0, | |
153 | (int __user *)regs->d3, (int __user *)regs->d4); | |
fde39441 GU |
154 | } |
155 | ||
156 | int copy_thread(unsigned long clone_flags, unsigned long usp, | |
afa86fc4 | 157 | unsigned long arg, struct task_struct *p) |
fde39441 | 158 | { |
20ecc91c AV |
159 | struct fork_frame { |
160 | struct switch_stack sw; | |
161 | struct pt_regs regs; | |
162 | } *frame; | |
fde39441 | 163 | |
20ecc91c | 164 | frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1; |
fde39441 | 165 | |
20ecc91c AV |
166 | p->thread.ksp = (unsigned long)frame; |
167 | p->thread.esp0 = (unsigned long)&frame->regs; | |
fde39441 GU |
168 | |
169 | /* | |
170 | * Must save the current SFC/DFC value, NOT the value when | |
171 | * the parent was last descheduled - RGH 10-08-96 | |
172 | */ | |
173 | p->thread.fs = get_fs().seg; | |
174 | ||
20ecc91c | 175 | if (unlikely(p->flags & PF_KTHREAD)) { |
533e6903 | 176 | /* kernel thread */ |
20ecc91c AV |
177 | memset(frame, 0, sizeof(struct fork_frame)); |
178 | frame->regs.sr = PS_S; | |
179 | frame->sw.a3 = usp; /* function */ | |
180 | frame->sw.d7 = arg; | |
181 | frame->sw.retpc = (unsigned long)ret_from_kernel_thread; | |
533e6903 AV |
182 | p->thread.usp = 0; |
183 | return 0; | |
184 | } | |
20ecc91c AV |
185 | memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs), |
186 | sizeof(struct fork_frame)); | |
187 | frame->regs.d0 = 0; | |
188 | frame->sw.retpc = (unsigned long)ret_from_fork; | |
189 | p->thread.usp = usp ?: rdusp(); | |
533e6903 AV |
190 | |
191 | if (clone_flags & CLONE_SETTLS) | |
20ecc91c | 192 | task_thread_info(p)->tp_value = frame->regs.d5; |
533e6903 | 193 | |
fde39441 GU |
194 | #ifdef CONFIG_FPU |
195 | if (!FPU_IS_EMU) { | |
196 | /* Copy the current fpu state */ | |
197 | asm volatile ("fsave %0" : : "m" (p->thread.fpstate[0]) : "memory"); | |
198 | ||
199 | if (!CPU_IS_060 ? p->thread.fpstate[0] : p->thread.fpstate[2]) { | |
200 | if (CPU_IS_COLDFIRE) { | |
201 | asm volatile ("fmovemd %/fp0-%/fp7,%0\n\t" | |
202 | "fmovel %/fpiar,%1\n\t" | |
203 | "fmovel %/fpcr,%2\n\t" | |
204 | "fmovel %/fpsr,%3" | |
205 | : | |
206 | : "m" (p->thread.fp[0]), | |
207 | "m" (p->thread.fpcntl[0]), | |
208 | "m" (p->thread.fpcntl[1]), | |
209 | "m" (p->thread.fpcntl[2]) | |
210 | : "memory"); | |
211 | } else { | |
212 | asm volatile ("fmovemx %/fp0-%/fp7,%0\n\t" | |
213 | "fmoveml %/fpiar/%/fpcr/%/fpsr,%1" | |
214 | : | |
215 | : "m" (p->thread.fp[0]), | |
216 | "m" (p->thread.fpcntl[0]) | |
217 | : "memory"); | |
218 | } | |
219 | } | |
220 | ||
221 | /* Restore the state in case the fpu was busy */ | |
222 | asm volatile ("frestore %0" : : "m" (p->thread.fpstate[0])); | |
223 | } | |
224 | #endif /* CONFIG_FPU */ | |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | /* Fill in the fpu structure for a core dump. */ | |
230 | #ifdef CONFIG_FPU | |
231 | int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) | |
232 | { | |
233 | char fpustate[216]; | |
234 | ||
235 | if (FPU_IS_EMU) { | |
236 | int i; | |
237 | ||
238 | memcpy(fpu->fpcntl, current->thread.fpcntl, 12); | |
239 | memcpy(fpu->fpregs, current->thread.fp, 96); | |
240 | /* Convert internal fpu reg representation | |
241 | * into long double format | |
242 | */ | |
243 | for (i = 0; i < 24; i += 3) | |
244 | fpu->fpregs[i] = ((fpu->fpregs[i] & 0xffff0000) << 15) | | |
245 | ((fpu->fpregs[i] & 0x0000ffff) << 16); | |
246 | return 1; | |
247 | } | |
248 | ||
249 | /* First dump the fpu context to avoid protocol violation. */ | |
250 | asm volatile ("fsave %0" :: "m" (fpustate[0]) : "memory"); | |
251 | if (!CPU_IS_060 ? !fpustate[0] : !fpustate[2]) | |
252 | return 0; | |
253 | ||
254 | if (CPU_IS_COLDFIRE) { | |
255 | asm volatile ("fmovel %/fpiar,%0\n\t" | |
256 | "fmovel %/fpcr,%1\n\t" | |
257 | "fmovel %/fpsr,%2\n\t" | |
258 | "fmovemd %/fp0-%/fp7,%3" | |
259 | : | |
260 | : "m" (fpu->fpcntl[0]), | |
261 | "m" (fpu->fpcntl[1]), | |
262 | "m" (fpu->fpcntl[2]), | |
263 | "m" (fpu->fpregs[0]) | |
264 | : "memory"); | |
265 | } else { | |
266 | asm volatile ("fmovem %/fpiar/%/fpcr/%/fpsr,%0" | |
267 | : | |
268 | : "m" (fpu->fpcntl[0]) | |
269 | : "memory"); | |
270 | asm volatile ("fmovemx %/fp0-%/fp7,%0" | |
271 | : | |
272 | : "m" (fpu->fpregs[0]) | |
273 | : "memory"); | |
274 | } | |
275 | ||
276 | return 1; | |
277 | } | |
278 | EXPORT_SYMBOL(dump_fpu); | |
279 | #endif /* CONFIG_FPU */ | |
280 | ||
fde39441 GU |
281 | unsigned long get_wchan(struct task_struct *p) |
282 | { | |
283 | unsigned long fp, pc; | |
284 | unsigned long stack_page; | |
285 | int count = 0; | |
286 | if (!p || p == current || p->state == TASK_RUNNING) | |
287 | return 0; | |
288 | ||
289 | stack_page = (unsigned long)task_stack_page(p); | |
290 | fp = ((struct switch_stack *)p->thread.ksp)->a6; | |
291 | do { | |
292 | if (fp < stack_page+sizeof(struct thread_info) || | |
293 | fp >= 8184+stack_page) | |
294 | return 0; | |
295 | pc = ((unsigned long *)fp)[1]; | |
296 | if (!in_sched_functions(pc)) | |
297 | return pc; | |
298 | fp = *(unsigned long *) fp; | |
299 | } while (count++ < 16); | |
300 | return 0; | |
301 | } |