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