blob: 04f8c67a610180413788684390d64bc613b8ca30 [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>
Heiko Carstens5a62b192008-04-17 07:46:25 +020039#include <linux/tick.h>
Heiko Carstensa8061702008-04-17 07:46:26 +020040#include <linux/elfcore.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/uaccess.h>
42#include <asm/pgtable.h>
43#include <asm/system.h>
44#include <asm/io.h>
45#include <asm/processor.h>
46#include <asm/irq.h>
47#include <asm/timer.h>
Heiko Carstensfae8b222007-10-22 12:52:39 +020048#include <asm/cpu.h>
Heiko Carstensa8061702008-04-17 07:46:26 +020049#include "entry.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +020051asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53/*
54 * Return saved PC of a blocked thread. used in kernel/sched.
55 * resume in entry.S does not create a new stack frame, it
56 * just stores the registers %r6-%r15 to the frame given by
57 * schedule. We want to return the address of the caller of
58 * schedule, so we have to walk the backchain one time to
59 * find the frame schedule() store its return address.
60 */
61unsigned long thread_saved_pc(struct task_struct *tsk)
62{
Heiko Carstenseb33c192006-01-14 13:20:57 -080063 struct stack_frame *sf, *low, *high;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Heiko Carstenseb33c192006-01-14 13:20:57 -080065 if (!tsk || !task_stack_page(tsk))
66 return 0;
67 low = task_stack_page(tsk);
68 high = (struct stack_frame *) task_pt_regs(tsk);
69 sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN);
70 if (sf <= low || sf > high)
71 return 0;
72 sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
73 if (sf <= low || sf > high)
74 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return sf->gprs[8];
76}
77
Josef 'Jeff' Sipek3e972392008-08-21 19:46:31 +020078DEFINE_PER_CPU(struct s390_idle_data, s390_idle) = {
79 .lock = __SPIN_LOCK_UNLOCKED(s390_idle.lock)
80};
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Heiko Carstens43ca5c32008-04-17 07:46:23 +020082static int s390_idle_enter(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Heiko Carstens43ca5c32008-04-17 07:46:23 +020084 struct s390_idle_data *idle;
Heiko Carstens43ca5c32008-04-17 07:46:23 +020085
Heiko Carstens43ca5c32008-04-17 07:46:23 +020086 idle = &__get_cpu_var(s390_idle);
87 spin_lock(&idle->lock);
88 idle->idle_count++;
89 idle->in_idle = 1;
90 idle->idle_enter = get_clock();
91 spin_unlock(&idle->lock);
Heiko Carstens773922e2008-07-14 09:59:06 +020092 vtime_stop_cpu_timer();
Heiko Carstens43ca5c32008-04-17 07:46:23 +020093 return NOTIFY_OK;
94}
95
96void s390_idle_leave(void)
97{
Heiko Carstensfae8b222007-10-22 12:52:39 +020098 struct s390_idle_data *idle;
99
Heiko Carstens773922e2008-07-14 09:59:06 +0200100 vtime_start_cpu_timer();
Heiko Carstensfae8b222007-10-22 12:52:39 +0200101 idle = &__get_cpu_var(s390_idle);
102 spin_lock(&idle->lock);
103 idle->idle_time += get_clock() - idle->idle_enter;
104 idle->in_idle = 0;
105 spin_unlock(&idle->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106}
107
Heiko Carstens77fa2242005-06-25 14:55:30 -0700108extern void s390_handle_mcck(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109/*
110 * The idle loop on a S390...
111 */
Adrian Bunkcdb04522006-03-24 03:15:57 -0800112static void default_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 /* CPU is going idle. */
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800115 local_irq_disable();
116 if (need_resched()) {
117 local_irq_enable();
118 return;
119 }
Heiko Carstens43ca5c32008-04-17 07:46:23 +0200120 if (s390_idle_enter() == NOTIFY_BAD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 local_irq_enable();
122 return;
123 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124#ifdef CONFIG_HOTPLUG_CPU
Heiko Carstens43ca5c32008-04-17 07:46:23 +0200125 if (cpu_is_offline(smp_processor_id())) {
Heiko Carstens1fca2512006-02-17 13:52:46 -0800126 preempt_enable_no_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 cpu_die();
Heiko Carstens1fca2512006-02-17 13:52:46 -0800128 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129#endif
Heiko Carstens77fa2242005-06-25 14:55:30 -0700130 local_mcck_disable();
131 if (test_thread_flag(TIF_MCCK_PENDING)) {
132 local_mcck_enable();
Heiko Carstens43ca5c32008-04-17 07:46:23 +0200133 s390_idle_leave();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700134 local_irq_enable();
135 s390_handle_mcck();
136 return;
137 }
Heiko Carstens1f194a42006-07-03 00:24:46 -0700138 trace_hardirqs_on();
Heiko Carstens632448f2008-11-14 18:18:04 +0100139 /* Don't trace preempt off for idle. */
140 stop_critical_timings();
Heiko Carstens77fa2242005-06-25 14:55:30 -0700141 /* Wait for external, I/O or machine check interrupt. */
Gerald Schaeferc1821c22007-02-05 21:18:17 +0100142 __load_psw_mask(psw_kernel_bits | PSW_MASK_WAIT |
Heiko Carstens77fa2242005-06-25 14:55:30 -0700143 PSW_MASK_IO | PSW_MASK_EXT);
Heiko Carstens632448f2008-11-14 18:18:04 +0100144 start_critical_timings();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145}
146
147void cpu_idle(void)
148{
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800149 for (;;) {
Thomas Gleixnere3381252008-07-19 09:33:21 +0200150 tick_nohz_stop_sched_tick(1);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800151 while (!need_resched())
152 default_idle();
Heiko Carstens5a62b192008-04-17 07:46:25 +0200153 tick_nohz_restart_sched_tick();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800154 preempt_enable_no_resched();
155 schedule();
156 preempt_disable();
157 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160extern void kernel_thread_starter(void);
161
Martin Schwidefsky94c12cc2006-09-28 16:56:43 +0200162asm(
163 ".align 4\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 "kernel_thread_starter:\n"
165 " la 2,0(10)\n"
166 " basr 14,9\n"
167 " la 2,0\n"
168 " br 11\n");
169
170int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
171{
172 struct pt_regs regs;
173
174 memset(&regs, 0, sizeof(regs));
Gerald Schaeferc1821c22007-02-05 21:18:17 +0100175 regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE;
177 regs.gprs[9] = (unsigned long) fn;
178 regs.gprs[10] = (unsigned long) arg;
179 regs.gprs[11] = (unsigned long) do_exit;
180 regs.orig_gpr2 = -1;
181
182 /* Ok, create the new process.. */
183 return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
184 0, &regs, 0, NULL, NULL);
185}
186
187/*
188 * Free current thread data structures etc..
189 */
190void exit_thread(void)
191{
192}
193
194void flush_thread(void)
195{
196 clear_used_math();
197 clear_tsk_thread_flag(current, TIF_USEDFPU);
198}
199
200void release_thread(struct task_struct *dead_task)
201{
202}
203
204int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp,
205 unsigned long unused,
206 struct task_struct * p, struct pt_regs * regs)
207{
208 struct fake_frame
209 {
210 struct stack_frame sf;
211 struct pt_regs childregs;
212 } *frame;
213
Al Viroc7584fb2006-01-12 01:05:49 -0800214 frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 p->thread.ksp = (unsigned long) frame;
216 /* Store access registers to kernel stack of new process. */
217 frame->childregs = *regs;
218 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
219 frame->childregs.gprs[15] = new_stackp;
220 frame->sf.back_chain = 0;
221
222 /* new return point is ret_from_fork */
223 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
224
225 /* fake return stack for resume(), don't go back to schedule */
226 frame->sf.gprs[9] = (unsigned long) frame;
227
228 /* Save access registers to new thread structure. */
229 save_access_regs(&p->thread.acrs[0]);
230
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800231#ifndef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 /*
233 * save fprs to current->thread.fp_regs to merge them with
234 * the emulated registers and then copy the result to the child.
235 */
236 save_fp_regs(&current->thread.fp_regs);
237 memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
238 sizeof(s390_fp_regs));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 /* Set a new TLS ? */
240 if (clone_flags & CLONE_SETTLS)
241 p->thread.acrs[0] = regs->gprs[6];
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800242#else /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 /* Save the fpu registers to new thread structure. */
244 save_fp_regs(&p->thread.fp_regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 /* Set a new TLS ? */
246 if (clone_flags & CLONE_SETTLS) {
247 if (test_thread_flag(TIF_31BIT)) {
248 p->thread.acrs[0] = (unsigned int) regs->gprs[6];
249 } else {
250 p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
251 p->thread.acrs[1] = (unsigned int) regs->gprs[6];
252 }
253 }
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800254#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 /* start new process with ar4 pointing to the correct address space */
256 p->thread.mm_segment = get_fs();
257 /* Don't copy debug registers */
258 memset(&p->thread.per_info,0,sizeof(p->thread.per_info));
259
260 return 0;
261}
262
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200263asmlinkage long sys_fork(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200265 struct pt_regs *regs = task_pt_regs(current);
266 return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267}
268
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200269asmlinkage long sys_clone(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200271 struct pt_regs *regs = task_pt_regs(current);
272 unsigned long clone_flags;
273 unsigned long newsp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 int __user *parent_tidptr, *child_tidptr;
275
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200276 clone_flags = regs->gprs[3];
277 newsp = regs->orig_gpr2;
278 parent_tidptr = (int __user *) regs->gprs[4];
279 child_tidptr = (int __user *) regs->gprs[5];
280 if (!newsp)
281 newsp = regs->gprs[15];
282 return do_fork(clone_flags, newsp, regs, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 parent_tidptr, child_tidptr);
284}
285
286/*
287 * This is trivial, and on the face of it looks like it
288 * could equally well be done in user mode.
289 *
290 * Not so, for quite unobvious reasons - register pressure.
291 * In user mode vfork() cannot have a stack frame, and if
292 * done by calling the "clone()" system call directly, you
293 * do not have enough call-clobbered registers to hold all
294 * the information you need.
295 */
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200296asmlinkage long sys_vfork(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200298 struct pt_regs *regs = task_pt_regs(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200300 regs->gprs[15], regs, 0, NULL, NULL);
301}
302
303asmlinkage void execve_tail(void)
304{
305 task_lock(current);
306 current->ptrace &= ~PT_DTRACE;
307 task_unlock(current);
308 current->thread.fp_regs.fpc = 0;
309 if (MACHINE_HAS_IEEE)
310 asm volatile("sfpc %0,%0" : : "d" (0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311}
312
313/*
314 * sys_execve() executes a new program.
315 */
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200316asmlinkage long sys_execve(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317{
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200318 struct pt_regs *regs = task_pt_regs(current);
319 char *filename;
320 unsigned long result;
321 int rc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200323 filename = getname((char __user *) regs->orig_gpr2);
324 if (IS_ERR(filename)) {
325 result = PTR_ERR(filename);
326 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 }
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200328 rc = do_execve(filename, (char __user * __user *) regs->gprs[3],
329 (char __user * __user *) regs->gprs[4], regs);
330 if (rc) {
331 result = rc;
332 goto out_putname;
333 }
334 execve_tail();
335 result = regs->gprs[2];
336out_putname:
337 putname(filename);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338out:
Martin Schwidefsky03ff9a22007-04-27 16:01:40 +0200339 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340}
341
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342/*
343 * fill in the FPU structure for a core dump.
344 */
345int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
346{
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800347#ifndef CONFIG_64BIT
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 /*
349 * save fprs to current->thread.fp_regs to merge them with
350 * the emulated registers and then copy the result to the dump.
351 */
352 save_fp_regs(&current->thread.fp_regs);
353 memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800354#else /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 save_fp_regs(fpregs);
Martin Schwidefsky347a8dc2006-01-06 00:19:28 -0800356#endif /* CONFIG_64BIT */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 return 1;
358}
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360unsigned long get_wchan(struct task_struct *p)
361{
362 struct stack_frame *sf, *low, *high;
363 unsigned long return_address;
364 int count;
365
Al Viro30af71202006-01-12 01:05:50 -0800366 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 return 0;
Al Viro30af71202006-01-12 01:05:50 -0800368 low = task_stack_page(p);
369 high = (struct stack_frame *) task_pt_regs(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
371 if (sf <= low || sf > high)
372 return 0;
373 for (count = 0; count < 16; count++) {
374 sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
375 if (sf <= low || sf > high)
376 return 0;
377 return_address = sf->gprs[8] & PSW_ADDR_INSN;
378 if (!in_sched_functions(return_address))
379 return return_address;
380 }
381 return 0;
382}
383