blob: a6a4729e0e942bcc23a49ad3c7a17f2ac56bbfd8 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#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>
Alexey Dobriyan4e950f62007-07-30 02:36:13 +040024#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#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>
Heiko Carstens5c699712008-01-26 14:11:01 +010038#include <linux/utsname.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#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>
Heiko Carstensfae8b222007-10-22 12:52:39 +020046#include <asm/cpu.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +020048asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
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 */
58unsigned long thread_saved_pc(struct task_struct *tsk)
59{
Heiko Carstenseb33c192006-01-14 13:20:57 -080060 struct stack_frame *sf, *low, *high;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Heiko Carstenseb33c192006-01-14 13:20:57 -080062 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return sf->gprs[8];
73}
74
75/*
76 * Need to know about CPUs going idle?
77 */
Alan Sterne041c682006-03-27 01:16:30 -080078static ATOMIC_NOTIFIER_HEAD(idle_chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80int register_idle_notifier(struct notifier_block *nb)
81{
Alan Sterne041c682006-03-27 01:16:30 -080082 return atomic_notifier_chain_register(&idle_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083}
84EXPORT_SYMBOL(register_idle_notifier);
85
86int unregister_idle_notifier(struct notifier_block *nb)
87{
Alan Sterne041c682006-03-27 01:16:30 -080088 return atomic_notifier_chain_unregister(&idle_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
90EXPORT_SYMBOL(unregister_idle_notifier);
91
92void do_monitor_call(struct pt_regs *regs, long interruption_code)
93{
Heiko Carstens0d2be082007-11-05 11:10:10 +010094#ifdef CONFIG_SMP
Heiko Carstensfae8b222007-10-22 12:52:39 +020095 struct s390_idle_data *idle;
96
97 idle = &__get_cpu_var(s390_idle);
98 spin_lock(&idle->lock);
99 idle->idle_time += get_clock() - idle->idle_enter;
100 idle->in_idle = 0;
101 spin_unlock(&idle->lock);
Heiko Carstens0d2be082007-11-05 11:10:10 +0100102#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 /* disable monitor call class 0 */
104 __ctl_clear_bit(8, 15);
105
Heiko Carstensdce55472007-07-10 11:24:21 +0200106 atomic_notifier_call_chain(&idle_chain, S390_CPU_NOT_IDLE,
107 (void *)(long) smp_processor_id());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108}
109
Heiko Carstens77fa2242005-06-25 14:55:30 -0700110extern void s390_handle_mcck(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111/*
112 * The idle loop on a S390...
113 */
Adrian Bunkcdb04522006-03-24 03:15:57 -0800114static void default_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 int cpu, rc;
Heiko Carstens0d2be082007-11-05 11:10:10 +0100117#ifdef CONFIG_SMP
Heiko Carstensfae8b222007-10-22 12:52:39 +0200118 struct s390_idle_data *idle;
Heiko Carstens0d2be082007-11-05 11:10:10 +0100119#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 /* CPU is going idle. */
122 cpu = smp_processor_id();
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800123
124 local_irq_disable();
125 if (need_resched()) {
126 local_irq_enable();
127 return;
128 }
129
Alan Sterne041c682006-03-27 01:16:30 -0800130 rc = atomic_notifier_call_chain(&idle_chain,
Heiko Carstensdce55472007-07-10 11:24:21 +0200131 S390_CPU_IDLE, (void *)(long) cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 if (rc != NOTIFY_OK && rc != NOTIFY_DONE)
133 BUG();
134 if (rc != NOTIFY_OK) {
135 local_irq_enable();
136 return;
137 }
138
139 /* enable monitor call class 0 */
140 __ctl_set_bit(8, 15);
141
142#ifdef CONFIG_HOTPLUG_CPU
Heiko Carstens1fca2512006-02-17 13:52:46 -0800143 if (cpu_is_offline(cpu)) {
144 preempt_enable_no_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 cpu_die();
Heiko Carstens1fca2512006-02-17 13:52:46 -0800146 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147#endif
148
Heiko Carstens77fa2242005-06-25 14:55:30 -0700149 local_mcck_disable();
150 if (test_thread_flag(TIF_MCCK_PENDING)) {
151 local_mcck_enable();
152 local_irq_enable();
153 s390_handle_mcck();
154 return;
155 }
Heiko Carstens0d2be082007-11-05 11:10:10 +0100156#ifdef CONFIG_SMP
Heiko Carstensfae8b222007-10-22 12:52:39 +0200157 idle = &__get_cpu_var(s390_idle);
158 spin_lock(&idle->lock);
159 idle->idle_count++;
160 idle->in_idle = 1;
161 idle->idle_enter = get_clock();
162 spin_unlock(&idle->lock);
Heiko Carstens0d2be082007-11-05 11:10:10 +0100163#endif
Heiko Carstens1f194a42006-07-03 00:24:46 -0700164 trace_hardirqs_on();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700165 /* Wait for external, I/O or machine check interrupt. */
Gerald Schaeferc1821c22007-02-05 21:18:17 +0100166 __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
Heiko Carstens77fa2242005-06-25 14:55:30 -0700167 PSW_MASK_IO | PSW_MASK_EXT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
170void cpu_idle(void)
171{
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800172 for (;;) {
173 while (!need_resched())
174 default_idle();
175
176 preempt_enable_no_resched();
177 schedule();
178 preempt_disable();
179 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180}
181
182void show_regs(struct pt_regs *regs)
183{
Heiko Carstens5c699712008-01-26 14:11:01 +0100184 print_modules();
185 printk("CPU: %d %s %s %.*s\n",
186 task_thread_info(current)->cpu, print_tainted(),
187 init_utsname()->release,
188 (int)strcspn(init_utsname()->version, " "),
189 init_utsname()->version);
190 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
191 current->comm, current->pid, current,
192 (void *) current->thread.ksp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 show_registers(regs);
194 /* Show stack backtrace if pt_regs is from kernel mode */
195 if (!(regs->psw.mask & PSW_MASK_PSTATE))
Heiko Carstensd2c993d2006-07-12 16:41:55 +0200196 show_trace(NULL, (unsigned long *) regs->gprs[15]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197}
198
199extern void kernel_thread_starter(void);
200
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200201asm(
202 ".align 4\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 "kernel_thread_starter:\n"
204 " la 2,0(10)\n"
205 " basr 14,9\n"
206 " la 2,0\n"
207 " br 11\n");
208
209int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
210{
211 struct pt_regs regs;
212
213 memset(&regs, 0, sizeof(regs));
Gerald Schaeferc1821c22007-02-05 21:18:17 +0100214 regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
216 regs.gprs[9] = (unsigned long) fn;
217 regs.gprs[10] = (unsigned long) arg;
218 regs.gprs[11] = (unsigned long) do_exit;
219 regs.orig_gpr2 = -1;
220
221 /* Ok, create the new process.. */
222 return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
223 0, &regs, 0, NULL, NULL);
224}
225
226/*
227 * Free current thread data structures etc..
228 */
229void exit_thread(void)
230{
231}
232
233void flush_thread(void)
234{
235 clear_used_math();
236 clear_tsk_thread_flag(current, TIF_USEDFPU);
237}
238
239void release_thread(struct task_struct *dead_task)
240{
241}
242
243int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
244 unsigned long unused,
245 struct task_struct * p, struct pt_regs * regs)
246{
247 struct fake_frame
248 {
249 struct stack_frame sf;
250 struct pt_regs childregs;
251 } *frame;
252
Al Viroc7584fb2006-01-12 01:05:49 -0800253 frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 p->thread.ksp = (unsigned long) frame;
255 /* Store access registers to kernel stack of new process. */
256 frame->childregs = *regs;
257 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
258 frame->childregs.gprs[15] = new_stackp;
259 frame->sf.back_chain = 0;
260
261 /* new return point is ret_from_fork */
262 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
263
264 /* fake return stack for resume(), don't go back to schedule */
265 frame->sf.gprs[9] = (unsigned long) frame;
266
267 /* Save access registers to new thread structure. */
268 save_access_regs(&p->thread.acrs[0]);
269
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800270#ifndef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 /*
272 * save fprs to current->thread.fp_regs to merge them with
273 * the emulated registers and then copy the result to the child.
274 */
275 save_fp_regs(&current->thread.fp_regs);
276 memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
277 sizeof(s390_fp_regs));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 /* Set a new TLS ? */
279 if (clone_flags & CLONE_SETTLS)
280 p->thread.acrs[0] = regs->gprs[6];
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800281#else /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 /* Save the fpu registers to new thread structure. */
283 save_fp_regs(&p->thread.fp_regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 /* Set a new TLS ? */
285 if (clone_flags & CLONE_SETTLS) {
286 if (test_thread_flag(TIF_31BIT)) {
287 p->thread.acrs[0] = (unsigned int) regs->gprs[6];
288 } else {
289 p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
290 p->thread.acrs[1] = (unsigned int) regs->gprs[6];
291 }
292 }
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800293#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 /* start new process with ar4 pointing to the correct address space */
295 p->thread.mm_segment = get_fs();
296 /* Don't copy debug registers */
297 memset(&p->thread.per_info,0,sizeof(p->thread.per_info));
298
299 return 0;
300}
301
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200302asmlinkage long sys_fork(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200304 struct pt_regs *regs = task_pt_regs(current);
305 return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306}
307
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200308asmlinkage long sys_clone(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200310 struct pt_regs *regs = task_pt_regs(current);
311 unsigned long clone_flags;
312 unsigned long newsp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 int __user *parent_tidptr, *child_tidptr;
314
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200315 clone_flags = regs->gprs[3];
316 newsp = regs->orig_gpr2;
317 parent_tidptr = (int __user *) regs->gprs[4];
318 child_tidptr = (int __user *) regs->gprs[5];
319 if (!newsp)
320 newsp = regs->gprs[15];
321 return do_fork(clone_flags, newsp, regs, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 parent_tidptr, child_tidptr);
323}
324
325/*
326 * This is trivial, and on the face of it looks like it
327 * could equally well be done in user mode.
328 *
329 * Not so, for quite unobvious reasons - register pressure.
330 * In user mode vfork() cannot have a stack frame, and if
331 * done by calling the "clone()" system call directly, you
332 * do not have enough call-clobbered registers to hold all
333 * the information you need.
334 */
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200335asmlinkage long sys_vfork(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200337 struct pt_regs *regs = task_pt_regs(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200339 regs->gprs[15], regs, 0, NULL, NULL);
340}
341
342asmlinkage void execve_tail(void)
343{
344 task_lock(current);
345 current->ptrace &= ~PT_DTRACE;
346 task_unlock(current);
347 current->thread.fp_regs.fpc = 0;
348 if (MACHINE_HAS_IEEE)
349 asm volatile("sfpc %0,%0" : : "d" (0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350}
351
352/*
353 * sys_execve() executes a new program.
354 */
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200355asmlinkage long sys_execve(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200357 struct pt_regs *regs = task_pt_regs(current);
358 char *filename;
359 unsigned long result;
360 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200362 filename = getname((char __user *) regs->orig_gpr2);
363 if (IS_ERR(filename)) {
364 result = PTR_ERR(filename);
365 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 }
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200367 rc = do_execve(filename, (char __user * __user *) regs->gprs[3],
368 (char __user * __user *) regs->gprs[4], regs);
369 if (rc) {
370 result = rc;
371 goto out_putname;
372 }
373 execve_tail();
374 result = regs->gprs[2];
375out_putname:
376 putname(filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377out:
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200378 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379}
380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381/*
382 * fill in the FPU structure for a core dump.
383 */
384int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
385{
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800386#ifndef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 /*
388 * save fprs to current->thread.fp_regs to merge them with
389 * the emulated registers and then copy the result to the dump.
390 */
391 save_fp_regs(&current->thread.fp_regs);
392 memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800393#else /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 save_fp_regs(fpregs);
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800395#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 return 1;
397}
398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399unsigned long get_wchan(struct task_struct *p)
400{
401 struct stack_frame *sf, *low, *high;
402 unsigned long return_address;
403 int count;
404
Al Viro30af7122006-01-12 01:05:50 -0800405 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 return 0;
Al Viro30af7122006-01-12 01:05:50 -0800407 low = task_stack_page(p);
408 high = (struct stack_frame *) task_pt_regs(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
410 if (sf <= low || sf > high)
411 return 0;
412 for (count = 0; count < 16; count++) {
413 sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
414 if (sf <= low || sf > high)
415 return 0;
416 return_address = sf->gprs[8] & PSW_ADDR_INSN;
417 if (!in_sched_functions(return_address))
418 return return_address;
419 }
420 return 0;
421}
422