Commit | Line | Data |
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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 | ||
1da177e4 LT |
18 | #include <linux/compiler.h> |
19 | #include <linux/cpu.h> | |
20 | #include <linux/errno.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/mm.h> | |
4e950f6f | 24 | #include <linux/fs.h> |
1da177e4 | 25 | #include <linux/smp.h> |
1da177e4 LT |
26 | #include <linux/stddef.h> |
27 | #include <linux/unistd.h> | |
28 | #include <linux/ptrace.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/vmalloc.h> | |
31 | #include <linux/user.h> | |
1da177e4 LT |
32 | #include <linux/interrupt.h> |
33 | #include <linux/delay.h> | |
34 | #include <linux/reboot.h> | |
35 | #include <linux/init.h> | |
36 | #include <linux/module.h> | |
37 | #include <linux/notifier.h> | |
5c699714 | 38 | #include <linux/utsname.h> |
1da177e4 LT |
39 | #include <asm/uaccess.h> |
40 | #include <asm/pgtable.h> | |
41 | #include <asm/system.h> | |
42 | #include <asm/io.h> | |
43 | #include <asm/processor.h> | |
44 | #include <asm/irq.h> | |
45 | #include <asm/timer.h> | |
fae8b22d | 46 | #include <asm/cpu.h> |
1da177e4 | 47 | |
94c12cc7 | 48 | asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); |
1da177e4 LT |
49 | |
50 | /* | |
51 | * Return saved PC of a blocked thread. used in kernel/sched. | |
52 | * resume in entry.S does not create a new stack frame, it | |
53 | * just stores the registers %r6-%r15 to the frame given by | |
54 | * schedule. We want to return the address of the caller of | |
55 | * schedule, so we have to walk the backchain one time to | |
56 | * find the frame schedule() store its return address. | |
57 | */ | |
58 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
59 | { | |
eb33c190 | 60 | struct stack_frame *sf, *low, *high; |
1da177e4 | 61 | |
eb33c190 HC |
62 | if (!tsk || !task_stack_page(tsk)) |
63 | return 0; | |
64 | low = task_stack_page(tsk); | |
65 | high = (struct stack_frame *) task_pt_regs(tsk); | |
66 | sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); | |
67 | if (sf <= low || sf > high) | |
68 | return 0; | |
69 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
70 | if (sf <= low || sf > high) | |
71 | return 0; | |
1da177e4 LT |
72 | return sf->gprs[8]; |
73 | } | |
74 | ||
75 | /* | |
76 | * Need to know about CPUs going idle? | |
77 | */ | |
e041c683 | 78 | static ATOMIC_NOTIFIER_HEAD(idle_chain); |
43ca5c3a | 79 | DEFINE_PER_CPU(struct s390_idle_data, s390_idle); |
1da177e4 LT |
80 | |
81 | int register_idle_notifier(struct notifier_block *nb) | |
82 | { | |
e041c683 | 83 | return atomic_notifier_chain_register(&idle_chain, nb); |
1da177e4 LT |
84 | } |
85 | EXPORT_SYMBOL(register_idle_notifier); | |
86 | ||
87 | int unregister_idle_notifier(struct notifier_block *nb) | |
88 | { | |
e041c683 | 89 | return atomic_notifier_chain_unregister(&idle_chain, nb); |
1da177e4 LT |
90 | } |
91 | EXPORT_SYMBOL(unregister_idle_notifier); | |
92 | ||
43ca5c3a HC |
93 | static int s390_idle_enter(void) |
94 | { | |
95 | struct s390_idle_data *idle; | |
96 | int nr_calls = 0; | |
97 | void *hcpu; | |
98 | int rc; | |
99 | ||
100 | hcpu = (void *)(long)smp_processor_id(); | |
101 | rc = __atomic_notifier_call_chain(&idle_chain, S390_CPU_IDLE, hcpu, -1, | |
102 | &nr_calls); | |
103 | if (rc == NOTIFY_BAD) { | |
104 | nr_calls--; | |
105 | __atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE, | |
106 | hcpu, nr_calls, NULL); | |
107 | return rc; | |
108 | } | |
109 | idle = &__get_cpu_var(s390_idle); | |
110 | spin_lock(&idle->lock); | |
111 | idle->idle_count++; | |
112 | idle->in_idle = 1; | |
113 | idle->idle_enter = get_clock(); | |
114 | spin_unlock(&idle->lock); | |
115 | return NOTIFY_OK; | |
116 | } | |
117 | ||
118 | void s390_idle_leave(void) | |
1da177e4 | 119 | { |
fae8b22d HC |
120 | struct s390_idle_data *idle; |
121 | ||
122 | idle = &__get_cpu_var(s390_idle); | |
123 | spin_lock(&idle->lock); | |
124 | idle->idle_time += get_clock() - idle->idle_enter; | |
125 | idle->in_idle = 0; | |
126 | spin_unlock(&idle->lock); | |
dce55470 HC |
127 | atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE, |
128 | (void *)(long) smp_processor_id()); | |
1da177e4 LT |
129 | } |
130 | ||
77fa2245 | 131 | extern void s390_handle_mcck(void); |
1da177e4 LT |
132 | /* |
133 | * The idle loop on a S390... | |
134 | */ | |
cdb04527 | 135 | static void default_idle(void) |
1da177e4 | 136 | { |
64c7c8f8 | 137 | /* CPU is going idle. */ |
1da177e4 | 138 | local_irq_disable(); |
64c7c8f8 | 139 | if (need_resched()) { |
1da177e4 | 140 | local_irq_enable(); |
64c7c8f8 NP |
141 | return; |
142 | } | |
43ca5c3a | 143 | if (s390_idle_enter() == NOTIFY_BAD) { |
1da177e4 LT |
144 | local_irq_enable(); |
145 | return; | |
146 | } | |
1da177e4 | 147 | #ifdef CONFIG_HOTPLUG_CPU |
43ca5c3a | 148 | if (cpu_is_offline(smp_processor_id())) { |
1fca251f | 149 | preempt_enable_no_resched(); |
1da177e4 | 150 | cpu_die(); |
1fca251f | 151 | } |
1da177e4 | 152 | #endif |
77fa2245 HC |
153 | local_mcck_disable(); |
154 | if (test_thread_flag(TIF_MCCK_PENDING)) { | |
155 | local_mcck_enable(); | |
43ca5c3a | 156 | s390_idle_leave(); |
77fa2245 HC |
157 | local_irq_enable(); |
158 | s390_handle_mcck(); | |
159 | return; | |
160 | } | |
1f194a4c | 161 | trace_hardirqs_on(); |
77fa2245 | 162 | /* Wait for external, I/O or machine check interrupt. */ |
c1821c2e | 163 | __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT | |
77fa2245 | 164 | PSW_MASK_IO | PSW_MASK_EXT); |
1da177e4 LT |
165 | } |
166 | ||
167 | void cpu_idle(void) | |
168 | { | |
5bfb5d69 NP |
169 | for (;;) { |
170 | while (!need_resched()) | |
171 | default_idle(); | |
172 | ||
173 | preempt_enable_no_resched(); | |
174 | schedule(); | |
175 | preempt_disable(); | |
176 | } | |
1da177e4 LT |
177 | } |
178 | ||
179 | void show_regs(struct pt_regs *regs) | |
180 | { | |
5c699714 HC |
181 | print_modules(); |
182 | printk("CPU: %d %s %s %.*s\n", | |
183 | task_thread_info(current)->cpu, print_tainted(), | |
184 | init_utsname()->release, | |
185 | (int)strcspn(init_utsname()->version, " "), | |
186 | init_utsname()->version); | |
187 | printk("Process %s (pid: %d, task: %p, ksp: %p)\n", | |
188 | current->comm, current->pid, current, | |
189 | (void *) current->thread.ksp); | |
1da177e4 LT |
190 | show_registers(regs); |
191 | /* Show stack backtrace if pt_regs is from kernel mode */ | |
192 | if (!(regs->psw.mask & PSW_MASK_PSTATE)) | |
d2c993d8 | 193 | show_trace(NULL, (unsigned long *) regs->gprs[15]); |
1da177e4 LT |
194 | } |
195 | ||
196 | extern void kernel_thread_starter(void); | |
197 | ||
94c12cc7 MS |
198 | asm( |
199 | ".align 4\n" | |
1da177e4 LT |
200 | "kernel_thread_starter:\n" |
201 | " la 2,0(10)\n" | |
202 | " basr 14,9\n" | |
203 | " la 2,0\n" | |
204 | " br 11\n"); | |
205 | ||
206 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
207 | { | |
208 | struct pt_regs regs; | |
209 | ||
210 | memset(®s, 0, sizeof(regs)); | |
c1821c2e | 211 | regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT; |
1da177e4 LT |
212 | regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE; |
213 | regs.gprs[9] = (unsigned long) fn; | |
214 | regs.gprs[10] = (unsigned long) arg; | |
215 | regs.gprs[11] = (unsigned long) do_exit; | |
216 | regs.orig_gpr2 = -1; | |
217 | ||
218 | /* Ok, create the new process.. */ | |
219 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, | |
220 | 0, ®s, 0, NULL, NULL); | |
221 | } | |
222 | ||
223 | /* | |
224 | * Free current thread data structures etc.. | |
225 | */ | |
226 | void exit_thread(void) | |
227 | { | |
228 | } | |
229 | ||
230 | void flush_thread(void) | |
231 | { | |
232 | clear_used_math(); | |
233 | clear_tsk_thread_flag(current, TIF_USEDFPU); | |
234 | } | |
235 | ||
236 | void release_thread(struct task_struct *dead_task) | |
237 | { | |
238 | } | |
239 | ||
240 | int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp, | |
241 | unsigned long unused, | |
242 | struct task_struct * p, struct pt_regs * regs) | |
243 | { | |
244 | struct fake_frame | |
245 | { | |
246 | struct stack_frame sf; | |
247 | struct pt_regs childregs; | |
248 | } *frame; | |
249 | ||
c7584fb6 | 250 | frame = container_of(task_pt_regs(p), struct fake_frame, childregs); |
1da177e4 LT |
251 | p->thread.ksp = (unsigned long) frame; |
252 | /* Store access registers to kernel stack of new process. */ | |
253 | frame->childregs = *regs; | |
254 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ | |
255 | frame->childregs.gprs[15] = new_stackp; | |
256 | frame->sf.back_chain = 0; | |
257 | ||
258 | /* new return point is ret_from_fork */ | |
259 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; | |
260 | ||
261 | /* fake return stack for resume(), don't go back to schedule */ | |
262 | frame->sf.gprs[9] = (unsigned long) frame; | |
263 | ||
264 | /* Save access registers to new thread structure. */ | |
265 | save_access_regs(&p->thread.acrs[0]); | |
266 | ||
347a8dc3 | 267 | #ifndef CONFIG_64BIT |
1da177e4 LT |
268 | /* |
269 | * save fprs to current->thread.fp_regs to merge them with | |
270 | * the emulated registers and then copy the result to the child. | |
271 | */ | |
272 | save_fp_regs(¤t->thread.fp_regs); | |
273 | memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs, | |
274 | sizeof(s390_fp_regs)); | |
1da177e4 LT |
275 | /* Set a new TLS ? */ |
276 | if (clone_flags & CLONE_SETTLS) | |
277 | p->thread.acrs[0] = regs->gprs[6]; | |
347a8dc3 | 278 | #else /* CONFIG_64BIT */ |
1da177e4 LT |
279 | /* Save the fpu registers to new thread structure. */ |
280 | save_fp_regs(&p->thread.fp_regs); | |
1da177e4 LT |
281 | /* Set a new TLS ? */ |
282 | if (clone_flags & CLONE_SETTLS) { | |
283 | if (test_thread_flag(TIF_31BIT)) { | |
284 | p->thread.acrs[0] = (unsigned int) regs->gprs[6]; | |
285 | } else { | |
286 | p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32); | |
287 | p->thread.acrs[1] = (unsigned int) regs->gprs[6]; | |
288 | } | |
289 | } | |
347a8dc3 | 290 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
291 | /* start new process with ar4 pointing to the correct address space */ |
292 | p->thread.mm_segment = get_fs(); | |
293 | /* Don't copy debug registers */ | |
294 | memset(&p->thread.per_info,0,sizeof(p->thread.per_info)); | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
03ff9a23 | 299 | asmlinkage long sys_fork(void) |
1da177e4 | 300 | { |
03ff9a23 MS |
301 | struct pt_regs *regs = task_pt_regs(current); |
302 | return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL); | |
1da177e4 LT |
303 | } |
304 | ||
03ff9a23 | 305 | asmlinkage long sys_clone(void) |
1da177e4 | 306 | { |
03ff9a23 MS |
307 | struct pt_regs *regs = task_pt_regs(current); |
308 | unsigned long clone_flags; | |
309 | unsigned long newsp; | |
1da177e4 LT |
310 | int __user *parent_tidptr, *child_tidptr; |
311 | ||
03ff9a23 MS |
312 | clone_flags = regs->gprs[3]; |
313 | newsp = regs->orig_gpr2; | |
314 | parent_tidptr = (int __user *) regs->gprs[4]; | |
315 | child_tidptr = (int __user *) regs->gprs[5]; | |
316 | if (!newsp) | |
317 | newsp = regs->gprs[15]; | |
318 | return do_fork(clone_flags, newsp, regs, 0, | |
1da177e4 LT |
319 | parent_tidptr, child_tidptr); |
320 | } | |
321 | ||
322 | /* | |
323 | * This is trivial, and on the face of it looks like it | |
324 | * could equally well be done in user mode. | |
325 | * | |
326 | * Not so, for quite unobvious reasons - register pressure. | |
327 | * In user mode vfork() cannot have a stack frame, and if | |
328 | * done by calling the "clone()" system call directly, you | |
329 | * do not have enough call-clobbered registers to hold all | |
330 | * the information you need. | |
331 | */ | |
03ff9a23 | 332 | asmlinkage long sys_vfork(void) |
1da177e4 | 333 | { |
03ff9a23 | 334 | struct pt_regs *regs = task_pt_regs(current); |
1da177e4 | 335 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, |
03ff9a23 MS |
336 | regs->gprs[15], regs, 0, NULL, NULL); |
337 | } | |
338 | ||
339 | asmlinkage void execve_tail(void) | |
340 | { | |
341 | task_lock(current); | |
342 | current->ptrace &= ~PT_DTRACE; | |
343 | task_unlock(current); | |
344 | current->thread.fp_regs.fpc = 0; | |
345 | if (MACHINE_HAS_IEEE) | |
346 | asm volatile("sfpc %0,%0" : : "d" (0)); | |
1da177e4 LT |
347 | } |
348 | ||
349 | /* | |
350 | * sys_execve() executes a new program. | |
351 | */ | |
03ff9a23 | 352 | asmlinkage long sys_execve(void) |
1da177e4 | 353 | { |
03ff9a23 MS |
354 | struct pt_regs *regs = task_pt_regs(current); |
355 | char *filename; | |
356 | unsigned long result; | |
357 | int rc; | |
358 | ||
359 | filename = getname((char __user *) regs->orig_gpr2); | |
360 | if (IS_ERR(filename)) { | |
361 | result = PTR_ERR(filename); | |
362 | goto out; | |
1da177e4 | 363 | } |
03ff9a23 MS |
364 | rc = do_execve(filename, (char __user * __user *) regs->gprs[3], |
365 | (char __user * __user *) regs->gprs[4], regs); | |
366 | if (rc) { | |
367 | result = rc; | |
368 | goto out_putname; | |
369 | } | |
370 | execve_tail(); | |
371 | result = regs->gprs[2]; | |
372 | out_putname: | |
373 | putname(filename); | |
1da177e4 | 374 | out: |
03ff9a23 | 375 | return result; |
1da177e4 LT |
376 | } |
377 | ||
1da177e4 LT |
378 | /* |
379 | * fill in the FPU structure for a core dump. | |
380 | */ | |
381 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) | |
382 | { | |
347a8dc3 | 383 | #ifndef CONFIG_64BIT |
1da177e4 LT |
384 | /* |
385 | * save fprs to current->thread.fp_regs to merge them with | |
386 | * the emulated registers and then copy the result to the dump. | |
387 | */ | |
388 | save_fp_regs(¤t->thread.fp_regs); | |
389 | memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs)); | |
347a8dc3 | 390 | #else /* CONFIG_64BIT */ |
1da177e4 | 391 | save_fp_regs(fpregs); |
347a8dc3 | 392 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
393 | return 1; |
394 | } | |
395 | ||
1da177e4 LT |
396 | unsigned long get_wchan(struct task_struct *p) |
397 | { | |
398 | struct stack_frame *sf, *low, *high; | |
399 | unsigned long return_address; | |
400 | int count; | |
401 | ||
30af7120 | 402 | if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) |
1da177e4 | 403 | return 0; |
30af7120 AV |
404 | low = task_stack_page(p); |
405 | high = (struct stack_frame *) task_pt_regs(p); | |
1da177e4 LT |
406 | sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); |
407 | if (sf <= low || sf > high) | |
408 | return 0; | |
409 | for (count = 0; count < 16; count++) { | |
410 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
411 | if (sf <= low || sf > high) | |
412 | return 0; | |
413 | return_address = sf->gprs[8] & PSW_ADDR_INSN; | |
414 | if (!in_sched_functions(return_address)) | |
415 | return return_address; | |
416 | } | |
417 | return 0; | |
418 | } | |
419 |