[PATCH] s390: improved machine check handling
[deliverable/linux.git] / arch / s390 / kernel / process.c
CommitLineData
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
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>
24#include <linux/mm.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>
40
41#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>
48
49asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
50
51/*
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.
58 */
59unsigned long thread_saved_pc(struct task_struct *tsk)
60{
61 struct stack_frame *sf;
62
63 sf = (struct stack_frame *) tsk->thread.ksp;
64 sf = (struct stack_frame *) sf->back_chain;
65 return sf->gprs[8];
66}
67
68/*
69 * Need to know about CPUs going idle?
70 */
71static struct notifier_block *idle_chain;
72
73int register_idle_notifier(struct notifier_block *nb)
74{
75 return notifier_chain_register(&idle_chain, nb);
76}
77EXPORT_SYMBOL(register_idle_notifier);
78
79int unregister_idle_notifier(struct notifier_block *nb)
80{
81 return notifier_chain_unregister(&idle_chain, nb);
82}
83EXPORT_SYMBOL(unregister_idle_notifier);
84
85void do_monitor_call(struct pt_regs *regs, long interruption_code)
86{
87 /* disable monitor call class 0 */
88 __ctl_clear_bit(8, 15);
89
90 notifier_call_chain(&idle_chain, CPU_NOT_IDLE,
91 (void *)(long) smp_processor_id());
92}
93
77fa2245 94extern void s390_handle_mcck(void);
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95/*
96 * The idle loop on a S390...
97 */
98void default_idle(void)
99{
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100 int cpu, rc;
101
102 local_irq_disable();
103 if (need_resched()) {
104 local_irq_enable();
105 schedule();
106 return;
107 }
108
109 /* CPU is going idle. */
110 cpu = smp_processor_id();
111 rc = notifier_call_chain(&idle_chain, CPU_IDLE, (void *)(long) cpu);
112 if (rc != NOTIFY_OK && rc != NOTIFY_DONE)
113 BUG();
114 if (rc != NOTIFY_OK) {
115 local_irq_enable();
116 return;
117 }
118
119 /* enable monitor call class 0 */
120 __ctl_set_bit(8, 15);
121
122#ifdef CONFIG_HOTPLUG_CPU
123 if (cpu_is_offline(smp_processor_id()))
124 cpu_die();
125#endif
126
77fa2245
HC
127 local_mcck_disable();
128 if (test_thread_flag(TIF_MCCK_PENDING)) {
129 local_mcck_enable();
130 local_irq_enable();
131 s390_handle_mcck();
132 return;
133 }
134
135 /* Wait for external, I/O or machine check interrupt. */
136 __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_WAIT |
137 PSW_MASK_IO | PSW_MASK_EXT);
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138}
139
140void cpu_idle(void)
141{
142 for (;;)
143 default_idle();
144}
145
146void show_regs(struct pt_regs *regs)
147{
148 struct task_struct *tsk = current;
149
150 printk("CPU: %d %s\n", tsk->thread_info->cpu, print_tainted());
151 printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
152 current->comm, current->pid, (void *) tsk,
153 (void *) tsk->thread.ksp);
154
155 show_registers(regs);
156 /* Show stack backtrace if pt_regs is from kernel mode */
157 if (!(regs->psw.mask & PSW_MASK_PSTATE))
158 show_trace(0,(unsigned long *) regs->gprs[15]);
159}
160
161extern void kernel_thread_starter(void);
162
163__asm__(".align 4\n"
164 "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));
175 regs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT;
176 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
214 frame = ((struct fake_frame *)
215 (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
216 p->thread.ksp = (unsigned long) frame;
217 /* Store access registers to kernel stack of new process. */
218 frame->childregs = *regs;
219 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
220 frame->childregs.gprs[15] = new_stackp;
221 frame->sf.back_chain = 0;
222
223 /* new return point is ret_from_fork */
224 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
225
226 /* fake return stack for resume(), don't go back to schedule */
227 frame->sf.gprs[9] = (unsigned long) frame;
228
229 /* Save access registers to new thread structure. */
230 save_access_regs(&p->thread.acrs[0]);
231
232#ifndef CONFIG_ARCH_S390X
233 /*
234 * save fprs to current->thread.fp_regs to merge them with
235 * the emulated registers and then copy the result to the child.
236 */
237 save_fp_regs(&current->thread.fp_regs);
238 memcpy(&p->thread.fp_regs, &current->thread.fp_regs,
239 sizeof(s390_fp_regs));
240 p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _SEGMENT_TABLE;
241 /* Set a new TLS ? */
242 if (clone_flags & CLONE_SETTLS)
243 p->thread.acrs[0] = regs->gprs[6];
244#else /* CONFIG_ARCH_S390X */
245 /* Save the fpu registers to new thread structure. */
246 save_fp_regs(&p->thread.fp_regs);
247 p->thread.user_seg = __pa((unsigned long) p->mm->pgd) | _REGION_TABLE;
248 /* Set a new TLS ? */
249 if (clone_flags & CLONE_SETTLS) {
250 if (test_thread_flag(TIF_31BIT)) {
251 p->thread.acrs[0] = (unsigned int) regs->gprs[6];
252 } else {
253 p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32);
254 p->thread.acrs[1] = (unsigned int) regs->gprs[6];
255 }
256 }
257#endif /* CONFIG_ARCH_S390X */
258 /* start new process with ar4 pointing to the correct address space */
259 p->thread.mm_segment = get_fs();
260 /* Don't copy debug registers */
261 memset(&p->thread.per_info,0,sizeof(p->thread.per_info));
262
263 return 0;
264}
265
266asmlinkage long sys_fork(struct pt_regs regs)
267{
268 return do_fork(SIGCHLD, regs.gprs[15], &regs, 0, NULL, NULL);
269}
270
271asmlinkage long sys_clone(struct pt_regs regs)
272{
273 unsigned long clone_flags;
274 unsigned long newsp;
275 int __user *parent_tidptr, *child_tidptr;
276
277 clone_flags = regs.gprs[3];
278 newsp = regs.orig_gpr2;
279 parent_tidptr = (int __user *) regs.gprs[4];
280 child_tidptr = (int __user *) regs.gprs[5];
281 if (!newsp)
282 newsp = regs.gprs[15];
283 return do_fork(clone_flags, newsp, &regs, 0,
284 parent_tidptr, child_tidptr);
285}
286
287/*
288 * This is trivial, and on the face of it looks like it
289 * could equally well be done in user mode.
290 *
291 * Not so, for quite unobvious reasons - register pressure.
292 * In user mode vfork() cannot have a stack frame, and if
293 * done by calling the "clone()" system call directly, you
294 * do not have enough call-clobbered registers to hold all
295 * the information you need.
296 */
297asmlinkage long sys_vfork(struct pt_regs regs)
298{
299 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
300 regs.gprs[15], &regs, 0, NULL, NULL);
301}
302
303/*
304 * sys_execve() executes a new program.
305 */
306asmlinkage long sys_execve(struct pt_regs regs)
307{
308 int error;
309 char * filename;
310
311 filename = getname((char __user *) regs.orig_gpr2);
312 error = PTR_ERR(filename);
313 if (IS_ERR(filename))
314 goto out;
315 error = do_execve(filename, (char __user * __user *) regs.gprs[3],
316 (char __user * __user *) regs.gprs[4], &regs);
317 if (error == 0) {
318 task_lock(current);
319 current->ptrace &= ~PT_DTRACE;
320 task_unlock(current);
321 current->thread.fp_regs.fpc = 0;
322 if (MACHINE_HAS_IEEE)
323 asm volatile("sfpc %0,%0" : : "d" (0));
324 }
325 putname(filename);
326out:
327 return error;
328}
329
330
331/*
332 * fill in the FPU structure for a core dump.
333 */
334int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
335{
336#ifndef CONFIG_ARCH_S390X
337 /*
338 * save fprs to current->thread.fp_regs to merge them with
339 * the emulated registers and then copy the result to the dump.
340 */
341 save_fp_regs(&current->thread.fp_regs);
342 memcpy(fpregs, &current->thread.fp_regs, sizeof(s390_fp_regs));
343#else /* CONFIG_ARCH_S390X */
344 save_fp_regs(fpregs);
345#endif /* CONFIG_ARCH_S390X */
346 return 1;
347}
348
349/*
350 * fill in the user structure for a core dump..
351 */
352void dump_thread(struct pt_regs * regs, struct user * dump)
353{
354
355/* changed the size calculations - should hopefully work better. lbt */
356 dump->magic = CMAGIC;
357 dump->start_code = 0;
358 dump->start_stack = regs->gprs[15] & ~(PAGE_SIZE - 1);
359 dump->u_tsize = current->mm->end_code >> PAGE_SHIFT;
360 dump->u_dsize = (current->mm->brk + PAGE_SIZE - 1) >> PAGE_SHIFT;
361 dump->u_dsize -= dump->u_tsize;
362 dump->u_ssize = 0;
363 if (dump->start_stack < TASK_SIZE)
364 dump->u_ssize = (TASK_SIZE - dump->start_stack) >> PAGE_SHIFT;
365 memcpy(&dump->regs, regs, sizeof(s390_regs));
366 dump_fpu (regs, &dump->regs.fp_regs);
367 dump->regs.per_info = current->thread.per_info;
368}
369
370unsigned long get_wchan(struct task_struct *p)
371{
372 struct stack_frame *sf, *low, *high;
373 unsigned long return_address;
374 int count;
375
376 if (!p || p == current || p->state == TASK_RUNNING || !p->thread_info)
377 return 0;
378 low = (struct stack_frame *) p->thread_info;
379 high = (struct stack_frame *)
380 ((unsigned long) p->thread_info + THREAD_SIZE) - 1;
381 sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN);
382 if (sf <= low || sf > high)
383 return 0;
384 for (count = 0; count < 16; count++) {
385 sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN);
386 if (sf <= low || sf > high)
387 return 0;
388 return_address = sf->gprs[8] & PSW_ADDR_INSN;
389 if (!in_sched_functions(return_address))
390 return return_address;
391 }
392 return 0;
393}
394
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