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1da177e4 LT |
1 | /* |
2 | * arch/s390/kernel/process.c | |
3 | * | |
4 | * S390 version | |
5 | * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation | |
6 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), | |
7 | * Hartmut Penner (hp@de.ibm.com), | |
8 | * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com), | |
9 | * | |
10 | * Derived from "arch/i386/kernel/process.c" | |
11 | * Copyright (C) 1995, Linus Torvalds | |
12 | */ | |
13 | ||
14 | /* | |
15 | * This file handles the architecture-dependent parts of process handling.. | |
16 | */ | |
17 | ||
18 | #include <linux/config.h> | |
19 | #include <linux/compiler.h> | |
20 | #include <linux/cpu.h> | |
21 | #include <linux/errno.h> | |
22 | #include <linux/sched.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/mm.h> | |
25 | #include <linux/smp.h> | |
26 | #include <linux/smp_lock.h> | |
27 | #include <linux/stddef.h> | |
28 | #include <linux/unistd.h> | |
29 | #include <linux/ptrace.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/vmalloc.h> | |
32 | #include <linux/user.h> | |
33 | #include <linux/a.out.h> | |
34 | #include <linux/interrupt.h> | |
35 | #include <linux/delay.h> | |
36 | #include <linux/reboot.h> | |
37 | #include <linux/init.h> | |
38 | #include <linux/module.h> | |
39 | #include <linux/notifier.h> | |
40 | ||
41 | #include <asm/uaccess.h> | |
42 | #include <asm/pgtable.h> | |
43 | #include <asm/system.h> | |
44 | #include <asm/io.h> | |
45 | #include <asm/processor.h> | |
46 | #include <asm/irq.h> | |
47 | #include <asm/timer.h> | |
48 | ||
49 | asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); | |
50 | ||
51 | /* | |
52 | * Return saved PC of a blocked thread. used in kernel/sched. | |
53 | * resume in entry.S does not create a new stack frame, it | |
54 | * just stores the registers %r6-%r15 to the frame given by | |
55 | * schedule. We want to return the address of the caller of | |
56 | * schedule, so we have to walk the backchain one time to | |
57 | * find the frame schedule() store its return address. | |
58 | */ | |
59 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
60 | { | |
61 | struct stack_frame *sf; | |
62 | ||
63 | sf = (struct stack_frame *) tsk->thread.ksp; | |
64 | sf = (struct stack_frame *) sf->back_chain; | |
65 | return sf->gprs[8]; | |
66 | } | |
67 | ||
68 | /* | |
69 | * Need to know about CPUs going idle? | |
70 | */ | |
71 | static struct notifier_block *idle_chain; | |
72 | ||
73 | int register_idle_notifier(struct notifier_block *nb) | |
74 | { | |
75 | return notifier_chain_register(&idle_chain, nb); | |
76 | } | |
77 | EXPORT_SYMBOL(register_idle_notifier); | |
78 | ||
79 | int unregister_idle_notifier(struct notifier_block *nb) | |
80 | { | |
81 | return notifier_chain_unregister(&idle_chain, nb); | |
82 | } | |
83 | EXPORT_SYMBOL(unregister_idle_notifier); | |
84 | ||
85 | void do_monitor_call(struct pt_regs *regs, long interruption_code) | |
86 | { | |
87 | /* disable monitor call class 0 */ | |
88 | __ctl_clear_bit(8, 15); | |
89 | ||
90 | notifier_call_chain(&idle_chain, CPU_NOT_IDLE, | |
91 | (void *)(long) smp_processor_id()); | |
92 | } | |
93 | ||
77fa2245 | 94 | extern void s390_handle_mcck(void); |
1da177e4 LT |
95 | /* |
96 | * The idle loop on a S390... | |
97 | */ | |
98 | void default_idle(void) | |
99 | { | |
1da177e4 LT |
100 | int cpu, rc; |
101 | ||
64c7c8f8 NP |
102 | /* CPU is going idle. */ |
103 | cpu = smp_processor_id(); | |
104 | ||
1da177e4 | 105 | local_irq_disable(); |
64c7c8f8 | 106 | if (need_resched()) { |
1da177e4 | 107 | local_irq_enable(); |
64c7c8f8 NP |
108 | return; |
109 | } | |
1da177e4 | 110 | |
1da177e4 LT |
111 | rc = notifier_call_chain(&idle_chain, CPU_IDLE, (void *)(long) cpu); |
112 | if (rc != NOTIFY_OK && rc != NOTIFY_DONE) | |
113 | BUG(); | |
114 | if (rc != NOTIFY_OK) { | |
115 | local_irq_enable(); | |
116 | return; | |
117 | } | |
118 | ||
119 | /* enable monitor call class 0 */ | |
120 | __ctl_set_bit(8, 15); | |
121 | ||
122 | #ifdef CONFIG_HOTPLUG_CPU | |
64c7c8f8 | 123 | if (cpu_is_offline(cpu)) |
1da177e4 LT |
124 | cpu_die(); |
125 | #endif | |
126 | ||
77fa2245 HC |
127 | local_mcck_disable(); |
128 | if (test_thread_flag(TIF_MCCK_PENDING)) { | |
129 | local_mcck_enable(); | |
130 | local_irq_enable(); | |
131 | s390_handle_mcck(); | |
132 | return; | |
133 | } | |
134 | ||
135 | /* Wait for external, I/O or machine check interrupt. */ | |
136 | __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_WAIT | | |
137 | PSW_MASK_IO | PSW_MASK_EXT); | |
1da177e4 LT |
138 | } |
139 | ||
140 | void cpu_idle(void) | |
141 | { | |
5bfb5d69 NP |
142 | for (;;) { |
143 | while (!need_resched()) | |
144 | default_idle(); | |
145 | ||
146 | preempt_enable_no_resched(); | |
147 | schedule(); | |
148 | preempt_disable(); | |
149 | } | |
1da177e4 LT |
150 | } |
151 | ||
152 | void show_regs(struct pt_regs *regs) | |
153 | { | |
154 | struct task_struct *tsk = current; | |
155 | ||
156 | printk("CPU: %d %s\n", tsk->thread_info->cpu, print_tainted()); | |
157 | printk("Process %s (pid: %d, task: %p, ksp: %p)\n", | |
158 | current->comm, current->pid, (void *) tsk, | |
159 | (void *) tsk->thread.ksp); | |
160 | ||
161 | show_registers(regs); | |
162 | /* Show stack backtrace if pt_regs is from kernel mode */ | |
163 | if (!(regs->psw.mask & PSW_MASK_PSTATE)) | |
164 | show_trace(0,(unsigned long *) regs->gprs[15]); | |
165 | } | |
166 | ||
167 | extern void kernel_thread_starter(void); | |
168 | ||
169 | __asm__(".align 4\n" | |
170 | "kernel_thread_starter:\n" | |
171 | " la 2,0(10)\n" | |
172 | " basr 14,9\n" | |
173 | " la 2,0\n" | |
174 | " br 11\n"); | |
175 | ||
176 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
177 | { | |
178 | struct pt_regs regs; | |
179 | ||
180 | memset(®s, 0, sizeof(regs)); | |
181 | regs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT; | |
182 | regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE; | |
183 | regs.gprs[9] = (unsigned long) fn; | |
184 | regs.gprs[10] = (unsigned long) arg; | |
185 | regs.gprs[11] = (unsigned long) do_exit; | |
186 | regs.orig_gpr2 = -1; | |
187 | ||
188 | /* Ok, create the new process.. */ | |
189 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, | |
190 | 0, ®s, 0, NULL, NULL); | |
191 | } | |
192 | ||
193 | /* | |
194 | * Free current thread data structures etc.. | |
195 | */ | |
196 | void exit_thread(void) | |
197 | { | |
198 | } | |
199 | ||
200 | void flush_thread(void) | |
201 | { | |
202 | clear_used_math(); | |
203 | clear_tsk_thread_flag(current, TIF_USEDFPU); | |
204 | } | |
205 | ||
206 | void release_thread(struct task_struct *dead_task) | |
207 | { | |
208 | } | |
209 | ||
210 | int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp, | |
211 | unsigned long unused, | |
212 | struct task_struct * p, struct pt_regs * regs) | |
213 | { | |
214 | struct fake_frame | |
215 | { | |
216 | struct stack_frame sf; | |
217 | struct pt_regs childregs; | |
218 | } *frame; | |
219 | ||
220 | frame = ((struct fake_frame *) | |
221 | (THREAD_SIZE + (unsigned long) p->thread_info)) - 1; | |
222 | p->thread.ksp = (unsigned long) frame; | |
223 | /* Store access registers to kernel stack of new process. */ | |
224 | frame->childregs = *regs; | |
225 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ | |
226 | frame->childregs.gprs[15] = new_stackp; | |
227 | frame->sf.back_chain = 0; | |
228 | ||
229 | /* new return point is ret_from_fork */ | |
230 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; | |
231 | ||
232 | /* fake return stack for resume(), don't go back to schedule */ | |
233 | frame->sf.gprs[9] = (unsigned long) frame; | |
234 | ||
235 | /* Save access registers to new thread structure. */ | |
236 | save_access_regs(&p->thread.acrs[0]); | |
237 | ||
347a8dc3 | 238 | #ifndef CONFIG_64BIT |
1da177e4 LT |
239 | /* |
240 | * save fprs to current->thread.fp_regs to merge them with | |
241 | * the emulated registers and then copy the result to the child. | |
242 | */ | |
243 | save_fp_regs(¤t->thread.fp_regs); | |
244 | memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs, | |
245 | sizeof(s390_fp_regs)); | |
246 | p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _SEGMENT_TABLE; | |
247 | /* Set a new TLS ? */ | |
248 | if (clone_flags & CLONE_SETTLS) | |
249 | p->thread.acrs[0] = regs->gprs[6]; | |
347a8dc3 | 250 | #else /* CONFIG_64BIT */ |
1da177e4 LT |
251 | /* Save the fpu registers to new thread structure. */ |
252 | save_fp_regs(&p->thread.fp_regs); | |
253 | p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _REGION_TABLE; | |
254 | /* Set a new TLS ? */ | |
255 | if (clone_flags & CLONE_SETTLS) { | |
256 | if (test_thread_flag(TIF_31BIT)) { | |
257 | p->thread.acrs[0] = (unsigned int) regs->gprs[6]; | |
258 | } else { | |
259 | p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32); | |
260 | p->thread.acrs[1] = (unsigned int) regs->gprs[6]; | |
261 | } | |
262 | } | |
347a8dc3 | 263 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
264 | /* start new process with ar4 pointing to the correct address space */ |
265 | p->thread.mm_segment = get_fs(); | |
266 | /* Don't copy debug registers */ | |
267 | memset(&p->thread.per_info,0,sizeof(p->thread.per_info)); | |
268 | ||
269 | return 0; | |
270 | } | |
271 | ||
272 | asmlinkage long sys_fork(struct pt_regs regs) | |
273 | { | |
274 | return do_fork(SIGCHLD, regs.gprs[15], ®s, 0, NULL, NULL); | |
275 | } | |
276 | ||
277 | asmlinkage long sys_clone(struct pt_regs regs) | |
278 | { | |
279 | unsigned long clone_flags; | |
280 | unsigned long newsp; | |
281 | int __user *parent_tidptr, *child_tidptr; | |
282 | ||
283 | clone_flags = regs.gprs[3]; | |
284 | newsp = regs.orig_gpr2; | |
285 | parent_tidptr = (int __user *) regs.gprs[4]; | |
286 | child_tidptr = (int __user *) regs.gprs[5]; | |
287 | if (!newsp) | |
288 | newsp = regs.gprs[15]; | |
289 | return do_fork(clone_flags, newsp, ®s, 0, | |
290 | parent_tidptr, child_tidptr); | |
291 | } | |
292 | ||
293 | /* | |
294 | * This is trivial, and on the face of it looks like it | |
295 | * could equally well be done in user mode. | |
296 | * | |
297 | * Not so, for quite unobvious reasons - register pressure. | |
298 | * In user mode vfork() cannot have a stack frame, and if | |
299 | * done by calling the "clone()" system call directly, you | |
300 | * do not have enough call-clobbered registers to hold all | |
301 | * the information you need. | |
302 | */ | |
303 | asmlinkage long sys_vfork(struct pt_regs regs) | |
304 | { | |
305 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, | |
306 | regs.gprs[15], ®s, 0, NULL, NULL); | |
307 | } | |
308 | ||
309 | /* | |
310 | * sys_execve() executes a new program. | |
311 | */ | |
312 | asmlinkage long sys_execve(struct pt_regs regs) | |
313 | { | |
314 | int error; | |
315 | char * filename; | |
316 | ||
317 | filename = getname((char __user *) regs.orig_gpr2); | |
318 | error = PTR_ERR(filename); | |
319 | if (IS_ERR(filename)) | |
320 | goto out; | |
321 | error = do_execve(filename, (char __user * __user *) regs.gprs[3], | |
322 | (char __user * __user *) regs.gprs[4], ®s); | |
323 | if (error == 0) { | |
324 | task_lock(current); | |
325 | current->ptrace &= ~PT_DTRACE; | |
326 | task_unlock(current); | |
327 | current->thread.fp_regs.fpc = 0; | |
328 | if (MACHINE_HAS_IEEE) | |
329 | asm volatile("sfpc %0,%0" : : "d" (0)); | |
330 | } | |
331 | putname(filename); | |
332 | out: | |
333 | return error; | |
334 | } | |
335 | ||
336 | ||
337 | /* | |
338 | * fill in the FPU structure for a core dump. | |
339 | */ | |
340 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) | |
341 | { | |
347a8dc3 | 342 | #ifndef CONFIG_64BIT |
1da177e4 LT |
343 | /* |
344 | * save fprs to current->thread.fp_regs to merge them with | |
345 | * the emulated registers and then copy the result to the dump. | |
346 | */ | |
347 | save_fp_regs(¤t->thread.fp_regs); | |
348 | memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs)); | |
347a8dc3 | 349 | #else /* CONFIG_64BIT */ |
1da177e4 | 350 | save_fp_regs(fpregs); |
347a8dc3 | 351 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
352 | return 1; |
353 | } | |
354 | ||
1da177e4 LT |
355 | unsigned long get_wchan(struct task_struct *p) |
356 | { | |
357 | struct stack_frame *sf, *low, *high; | |
358 | unsigned long return_address; | |
359 | int count; | |
360 | ||
361 | if (!p || p == current || p->state == TASK_RUNNING || !p->thread_info) | |
362 | return 0; | |
363 | low = (struct stack_frame *) p->thread_info; | |
364 | high = (struct stack_frame *) | |
365 | ((unsigned long) p->thread_info + THREAD_SIZE) - 1; | |
366 | sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); | |
367 | if (sf <= low || sf > high) | |
368 | return 0; | |
369 | for (count = 0; count < 16; count++) { | |
370 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
371 | if (sf <= low || sf > high) | |
372 | return 0; | |
373 | return_address = sf->gprs[8] & PSW_ADDR_INSN; | |
374 | if (!in_sched_functions(return_address)) | |
375 | return return_address; | |
376 | } | |
377 | return 0; | |
378 | } | |
379 |