2 * arch/s390/kernel/process.c
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),
10 * Derived from "arch/i386/kernel/process.c"
11 * Copyright (C) 1995, Linus Torvalds
15 * This file handles the architecture-dependent parts of process handling..
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>
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>
41 #include <asm/uaccess.h>
42 #include <asm/pgtable.h>
43 #include <asm/system.h>
45 #include <asm/processor.h>
47 #include <asm/timer.h>
49 asmlinkage
void ret_from_fork(void) __asm__("ret_from_fork");
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.
59 unsigned long thread_saved_pc(struct task_struct
*tsk
)
61 struct stack_frame
*sf
;
63 sf
= (struct stack_frame
*) tsk
->thread
.ksp
;
64 sf
= (struct stack_frame
*) sf
->back_chain
;
69 * Need to know about CPUs going idle?
71 static struct notifier_block
*idle_chain
;
73 int register_idle_notifier(struct notifier_block
*nb
)
75 return notifier_chain_register(&idle_chain
, nb
);
77 EXPORT_SYMBOL(register_idle_notifier
);
79 int unregister_idle_notifier(struct notifier_block
*nb
)
81 return notifier_chain_unregister(&idle_chain
, nb
);
83 EXPORT_SYMBOL(unregister_idle_notifier
);
85 void do_monitor_call(struct pt_regs
*regs
, long interruption_code
)
87 /* disable monitor call class 0 */
88 __ctl_clear_bit(8, 15);
90 notifier_call_chain(&idle_chain
, CPU_NOT_IDLE
,
91 (void *)(long) smp_processor_id());
95 * The idle loop on a S390...
97 void default_idle(void)
104 if (need_resched()) {
110 /* CPU is going idle. */
111 cpu
= smp_processor_id();
112 rc
= notifier_call_chain(&idle_chain
, CPU_IDLE
, (void *)(long) cpu
);
113 if (rc
!= NOTIFY_OK
&& rc
!= NOTIFY_DONE
)
115 if (rc
!= NOTIFY_OK
) {
120 /* enable monitor call class 0 */
121 __ctl_set_bit(8, 15);
123 #ifdef CONFIG_HOTPLUG_CPU
124 if (cpu_is_offline(smp_processor_id()))
129 * Wait for external, I/O or machine check interrupt and
130 * switch off machine check bit after the wait has ended.
132 wait_psw
.mask
= PSW_KERNEL_BITS
| PSW_MASK_MCHECK
| PSW_MASK_WAIT
|
133 PSW_MASK_IO
| PSW_MASK_EXT
;
134 #ifndef CONFIG_ARCH_S390X
137 "0: la %0,1f-0b(%0)\n"
141 "1: la %0,2f-1b(%0)\n"
147 : "=&a" (reg
) : "a" (&wait_psw
) : "memory", "cc" );
148 #else /* CONFIG_ARCH_S390X */
158 : "=&a" (reg
) : "a" (&wait_psw
) : "memory", "cc" );
159 #endif /* CONFIG_ARCH_S390X */
168 void show_regs(struct pt_regs
*regs
)
170 struct task_struct
*tsk
= current
;
172 printk("CPU: %d %s\n", tsk
->thread_info
->cpu
, print_tainted());
173 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
174 current
->comm
, current
->pid
, (void *) tsk
,
175 (void *) tsk
->thread
.ksp
);
177 show_registers(regs
);
178 /* Show stack backtrace if pt_regs is from kernel mode */
179 if (!(regs
->psw
.mask
& PSW_MASK_PSTATE
))
180 show_trace(0,(unsigned long *) regs
->gprs
[15]);
183 extern void kernel_thread_starter(void);
186 "kernel_thread_starter:\n"
192 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
196 memset(®s
, 0, sizeof(regs
));
197 regs
.psw
.mask
= PSW_KERNEL_BITS
| PSW_MASK_IO
| PSW_MASK_EXT
;
198 regs
.psw
.addr
= (unsigned long) kernel_thread_starter
| PSW_ADDR_AMODE
;
199 regs
.gprs
[9] = (unsigned long) fn
;
200 regs
.gprs
[10] = (unsigned long) arg
;
201 regs
.gprs
[11] = (unsigned long) do_exit
;
204 /* Ok, create the new process.. */
205 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
,
206 0, ®s
, 0, NULL
, NULL
);
210 * Free current thread data structures etc..
212 void exit_thread(void)
216 void flush_thread(void)
219 clear_tsk_thread_flag(current
, TIF_USEDFPU
);
222 void release_thread(struct task_struct
*dead_task
)
226 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long new_stackp
,
227 unsigned long unused
,
228 struct task_struct
* p
, struct pt_regs
* regs
)
232 struct stack_frame sf
;
233 struct pt_regs childregs
;
236 frame
= ((struct fake_frame
*)
237 (THREAD_SIZE
+ (unsigned long) p
->thread_info
)) - 1;
238 p
->thread
.ksp
= (unsigned long) frame
;
239 /* Store access registers to kernel stack of new process. */
240 frame
->childregs
= *regs
;
241 frame
->childregs
.gprs
[2] = 0; /* child returns 0 on fork. */
242 frame
->childregs
.gprs
[15] = new_stackp
;
243 frame
->sf
.back_chain
= 0;
245 /* new return point is ret_from_fork */
246 frame
->sf
.gprs
[8] = (unsigned long) ret_from_fork
;
248 /* fake return stack for resume(), don't go back to schedule */
249 frame
->sf
.gprs
[9] = (unsigned long) frame
;
251 /* Save access registers to new thread structure. */
252 save_access_regs(&p
->thread
.acrs
[0]);
254 #ifndef CONFIG_ARCH_S390X
256 * save fprs to current->thread.fp_regs to merge them with
257 * the emulated registers and then copy the result to the child.
259 save_fp_regs(¤t
->thread
.fp_regs
);
260 memcpy(&p
->thread
.fp_regs
, ¤t
->thread
.fp_regs
,
261 sizeof(s390_fp_regs
));
262 p
->thread
.user_seg
= __pa((unsigned long) p
->mm
->pgd
) | _SEGMENT_TABLE
;
263 /* Set a new TLS ? */
264 if (clone_flags
& CLONE_SETTLS
)
265 p
->thread
.acrs
[0] = regs
->gprs
[6];
266 #else /* CONFIG_ARCH_S390X */
267 /* Save the fpu registers to new thread structure. */
268 save_fp_regs(&p
->thread
.fp_regs
);
269 p
->thread
.user_seg
= __pa((unsigned long) p
->mm
->pgd
) | _REGION_TABLE
;
270 /* Set a new TLS ? */
271 if (clone_flags
& CLONE_SETTLS
) {
272 if (test_thread_flag(TIF_31BIT
)) {
273 p
->thread
.acrs
[0] = (unsigned int) regs
->gprs
[6];
275 p
->thread
.acrs
[0] = (unsigned int)(regs
->gprs
[6] >> 32);
276 p
->thread
.acrs
[1] = (unsigned int) regs
->gprs
[6];
279 #endif /* CONFIG_ARCH_S390X */
280 /* start new process with ar4 pointing to the correct address space */
281 p
->thread
.mm_segment
= get_fs();
282 /* Don't copy debug registers */
283 memset(&p
->thread
.per_info
,0,sizeof(p
->thread
.per_info
));
288 asmlinkage
long sys_fork(struct pt_regs regs
)
290 return do_fork(SIGCHLD
, regs
.gprs
[15], ®s
, 0, NULL
, NULL
);
293 asmlinkage
long sys_clone(struct pt_regs regs
)
295 unsigned long clone_flags
;
297 int __user
*parent_tidptr
, *child_tidptr
;
299 clone_flags
= regs
.gprs
[3];
300 newsp
= regs
.orig_gpr2
;
301 parent_tidptr
= (int __user
*) regs
.gprs
[4];
302 child_tidptr
= (int __user
*) regs
.gprs
[5];
304 newsp
= regs
.gprs
[15];
305 return do_fork(clone_flags
, newsp
, ®s
, 0,
306 parent_tidptr
, child_tidptr
);
310 * This is trivial, and on the face of it looks like it
311 * could equally well be done in user mode.
313 * Not so, for quite unobvious reasons - register pressure.
314 * In user mode vfork() cannot have a stack frame, and if
315 * done by calling the "clone()" system call directly, you
316 * do not have enough call-clobbered registers to hold all
317 * the information you need.
319 asmlinkage
long sys_vfork(struct pt_regs regs
)
321 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
,
322 regs
.gprs
[15], ®s
, 0, NULL
, NULL
);
326 * sys_execve() executes a new program.
328 asmlinkage
long sys_execve(struct pt_regs regs
)
333 filename
= getname((char __user
*) regs
.orig_gpr2
);
334 error
= PTR_ERR(filename
);
335 if (IS_ERR(filename
))
337 error
= do_execve(filename
, (char __user
* __user
*) regs
.gprs
[3],
338 (char __user
* __user
*) regs
.gprs
[4], ®s
);
341 current
->ptrace
&= ~PT_DTRACE
;
342 task_unlock(current
);
343 current
->thread
.fp_regs
.fpc
= 0;
344 if (MACHINE_HAS_IEEE
)
345 asm volatile("sfpc %0,%0" : : "d" (0));
354 * fill in the FPU structure for a core dump.
356 int dump_fpu (struct pt_regs
* regs
, s390_fp_regs
*fpregs
)
358 #ifndef CONFIG_ARCH_S390X
360 * save fprs to current->thread.fp_regs to merge them with
361 * the emulated registers and then copy the result to the dump.
363 save_fp_regs(¤t
->thread
.fp_regs
);
364 memcpy(fpregs
, ¤t
->thread
.fp_regs
, sizeof(s390_fp_regs
));
365 #else /* CONFIG_ARCH_S390X */
366 save_fp_regs(fpregs
);
367 #endif /* CONFIG_ARCH_S390X */
372 * fill in the user structure for a core dump..
374 void dump_thread(struct pt_regs
* regs
, struct user
* dump
)
377 /* changed the size calculations - should hopefully work better. lbt */
378 dump
->magic
= CMAGIC
;
379 dump
->start_code
= 0;
380 dump
->start_stack
= regs
->gprs
[15] & ~(PAGE_SIZE
- 1);
381 dump
->u_tsize
= current
->mm
->end_code
>> PAGE_SHIFT
;
382 dump
->u_dsize
= (current
->mm
->brk
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
383 dump
->u_dsize
-= dump
->u_tsize
;
385 if (dump
->start_stack
< TASK_SIZE
)
386 dump
->u_ssize
= (TASK_SIZE
- dump
->start_stack
) >> PAGE_SHIFT
;
387 memcpy(&dump
->regs
, regs
, sizeof(s390_regs
));
388 dump_fpu (regs
, &dump
->regs
.fp_regs
);
389 dump
->regs
.per_info
= current
->thread
.per_info
;
392 unsigned long get_wchan(struct task_struct
*p
)
394 struct stack_frame
*sf
, *low
, *high
;
395 unsigned long return_address
;
398 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
|| !p
->thread_info
)
400 low
= (struct stack_frame
*) p
->thread_info
;
401 high
= (struct stack_frame
*)
402 ((unsigned long) p
->thread_info
+ THREAD_SIZE
) - 1;
403 sf
= (struct stack_frame
*) (p
->thread
.ksp
& PSW_ADDR_INSN
);
404 if (sf
<= low
|| sf
> high
)
406 for (count
= 0; count
< 16; count
++) {
407 sf
= (struct stack_frame
*) (sf
->back_chain
& PSW_ADDR_INSN
);
408 if (sf
<= low
|| sf
> high
)
410 return_address
= sf
->gprs
[8] & PSW_ADDR_INSN
;
411 if (!in_sched_functions(return_address
))
412 return return_address
;