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 */
169 void show_regs(struct pt_regs
*regs
)
171 struct task_struct
*tsk
= current
;
173 printk("CPU: %d %s\n", tsk
->thread_info
->cpu
, print_tainted());
174 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
175 current
->comm
, current
->pid
, (void *) tsk
,
176 (void *) tsk
->thread
.ksp
);
178 show_registers(regs
);
179 /* Show stack backtrace if pt_regs is from kernel mode */
180 if (!(regs
->psw
.mask
& PSW_MASK_PSTATE
))
181 show_trace(0,(unsigned long *) regs
->gprs
[15]);
184 extern void kernel_thread_starter(void);
187 "kernel_thread_starter:\n"
193 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
197 memset(®s
, 0, sizeof(regs
));
198 regs
.psw
.mask
= PSW_KERNEL_BITS
| PSW_MASK_IO
| PSW_MASK_EXT
;
199 regs
.psw
.addr
= (unsigned long) kernel_thread_starter
| PSW_ADDR_AMODE
;
200 regs
.gprs
[9] = (unsigned long) fn
;
201 regs
.gprs
[10] = (unsigned long) arg
;
202 regs
.gprs
[11] = (unsigned long) do_exit
;
205 /* Ok, create the new process.. */
206 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
,
207 0, ®s
, 0, NULL
, NULL
);
211 * Free current thread data structures etc..
213 void exit_thread(void)
217 void flush_thread(void)
220 current
->used_math
= 0;
221 clear_tsk_thread_flag(current
, TIF_USEDFPU
);
224 void release_thread(struct task_struct
*dead_task
)
228 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long new_stackp
,
229 unsigned long unused
,
230 struct task_struct
* p
, struct pt_regs
* regs
)
234 struct stack_frame sf
;
235 struct pt_regs childregs
;
238 frame
= ((struct fake_frame
*)
239 (THREAD_SIZE
+ (unsigned long) p
->thread_info
)) - 1;
240 p
->thread
.ksp
= (unsigned long) frame
;
241 p
->set_child_tid
= p
->clear_child_tid
= NULL
;
242 /* Store access registers to kernel stack of new process. */
243 frame
->childregs
= *regs
;
244 frame
->childregs
.gprs
[2] = 0; /* child returns 0 on fork. */
245 frame
->childregs
.gprs
[15] = new_stackp
;
246 frame
->sf
.back_chain
= 0;
248 /* new return point is ret_from_fork */
249 frame
->sf
.gprs
[8] = (unsigned long) ret_from_fork
;
251 /* fake return stack for resume(), don't go back to schedule */
252 frame
->sf
.gprs
[9] = (unsigned long) frame
;
254 /* Save access registers to new thread structure. */
255 save_access_regs(&p
->thread
.acrs
[0]);
257 #ifndef CONFIG_ARCH_S390X
259 * save fprs to current->thread.fp_regs to merge them with
260 * the emulated registers and then copy the result to the child.
262 save_fp_regs(¤t
->thread
.fp_regs
);
263 memcpy(&p
->thread
.fp_regs
, ¤t
->thread
.fp_regs
,
264 sizeof(s390_fp_regs
));
265 p
->thread
.user_seg
= __pa((unsigned long) p
->mm
->pgd
) | _SEGMENT_TABLE
;
266 /* Set a new TLS ? */
267 if (clone_flags
& CLONE_SETTLS
)
268 p
->thread
.acrs
[0] = regs
->gprs
[6];
269 #else /* CONFIG_ARCH_S390X */
270 /* Save the fpu registers to new thread structure. */
271 save_fp_regs(&p
->thread
.fp_regs
);
272 p
->thread
.user_seg
= __pa((unsigned long) p
->mm
->pgd
) | _REGION_TABLE
;
273 /* Set a new TLS ? */
274 if (clone_flags
& CLONE_SETTLS
) {
275 if (test_thread_flag(TIF_31BIT
)) {
276 p
->thread
.acrs
[0] = (unsigned int) regs
->gprs
[6];
278 p
->thread
.acrs
[0] = (unsigned int)(regs
->gprs
[6] >> 32);
279 p
->thread
.acrs
[1] = (unsigned int) regs
->gprs
[6];
282 #endif /* CONFIG_ARCH_S390X */
283 /* start new process with ar4 pointing to the correct address space */
284 p
->thread
.mm_segment
= get_fs();
285 /* Don't copy debug registers */
286 memset(&p
->thread
.per_info
,0,sizeof(p
->thread
.per_info
));
291 asmlinkage
long sys_fork(struct pt_regs regs
)
293 return do_fork(SIGCHLD
, regs
.gprs
[15], ®s
, 0, NULL
, NULL
);
296 asmlinkage
long sys_clone(struct pt_regs regs
)
298 unsigned long clone_flags
;
300 int __user
*parent_tidptr
, *child_tidptr
;
302 clone_flags
= regs
.gprs
[3];
303 newsp
= regs
.orig_gpr2
;
304 parent_tidptr
= (int __user
*) regs
.gprs
[4];
305 child_tidptr
= (int __user
*) regs
.gprs
[5];
307 newsp
= regs
.gprs
[15];
308 return do_fork(clone_flags
, newsp
, ®s
, 0,
309 parent_tidptr
, child_tidptr
);
313 * This is trivial, and on the face of it looks like it
314 * could equally well be done in user mode.
316 * Not so, for quite unobvious reasons - register pressure.
317 * In user mode vfork() cannot have a stack frame, and if
318 * done by calling the "clone()" system call directly, you
319 * do not have enough call-clobbered registers to hold all
320 * the information you need.
322 asmlinkage
long sys_vfork(struct pt_regs regs
)
324 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
,
325 regs
.gprs
[15], ®s
, 0, NULL
, NULL
);
329 * sys_execve() executes a new program.
331 asmlinkage
long sys_execve(struct pt_regs regs
)
336 filename
= getname((char __user
*) regs
.orig_gpr2
);
337 error
= PTR_ERR(filename
);
338 if (IS_ERR(filename
))
340 error
= do_execve(filename
, (char __user
* __user
*) regs
.gprs
[3],
341 (char __user
* __user
*) regs
.gprs
[4], ®s
);
343 current
->ptrace
&= ~PT_DTRACE
;
344 current
->thread
.fp_regs
.fpc
= 0;
345 if (MACHINE_HAS_IEEE
)
346 asm volatile("sfpc %0,%0" : : "d" (0));
355 * fill in the FPU structure for a core dump.
357 int dump_fpu (struct pt_regs
* regs
, s390_fp_regs
*fpregs
)
359 #ifndef CONFIG_ARCH_S390X
361 * save fprs to current->thread.fp_regs to merge them with
362 * the emulated registers and then copy the result to the dump.
364 save_fp_regs(¤t
->thread
.fp_regs
);
365 memcpy(fpregs
, ¤t
->thread
.fp_regs
, sizeof(s390_fp_regs
));
366 #else /* CONFIG_ARCH_S390X */
367 save_fp_regs(fpregs
);
368 #endif /* CONFIG_ARCH_S390X */
373 * fill in the user structure for a core dump..
375 void dump_thread(struct pt_regs
* regs
, struct user
* dump
)
378 /* changed the size calculations - should hopefully work better. lbt */
379 dump
->magic
= CMAGIC
;
380 dump
->start_code
= 0;
381 dump
->start_stack
= regs
->gprs
[15] & ~(PAGE_SIZE
- 1);
382 dump
->u_tsize
= current
->mm
->end_code
>> PAGE_SHIFT
;
383 dump
->u_dsize
= (current
->mm
->brk
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
384 dump
->u_dsize
-= dump
->u_tsize
;
386 if (dump
->start_stack
< TASK_SIZE
)
387 dump
->u_ssize
= (TASK_SIZE
- dump
->start_stack
) >> PAGE_SHIFT
;
388 memcpy(&dump
->regs
, regs
, sizeof(s390_regs
));
389 dump_fpu (regs
, &dump
->regs
.fp_regs
);
390 dump
->regs
.per_info
= current
->thread
.per_info
;
393 unsigned long get_wchan(struct task_struct
*p
)
395 struct stack_frame
*sf
, *low
, *high
;
396 unsigned long return_address
;
399 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
|| !p
->thread_info
)
401 low
= (struct stack_frame
*) p
->thread_info
;
402 high
= (struct stack_frame
*)
403 ((unsigned long) p
->thread_info
+ THREAD_SIZE
) - 1;
404 sf
= (struct stack_frame
*) (p
->thread
.ksp
& PSW_ADDR_INSN
);
405 if (sf
<= low
|| sf
> high
)
407 for (count
= 0; count
< 16; count
++) {
408 sf
= (struct stack_frame
*) (sf
->back_chain
& PSW_ADDR_INSN
);
409 if (sf
<= low
|| sf
> high
)
411 return_address
= sf
->gprs
[8] & PSW_ADDR_INSN
;
412 if (!in_sched_functions(return_address
))
413 return return_address
;