2 * linux/arch/ppc64/kernel/process.c
4 * Derived from "arch/i386/kernel/process.c"
5 * Copyright (C) 1995 Linus Torvalds
7 * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
8 * Paul Mackerras (paulus@cs.anu.edu.au)
11 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
19 #include <linux/config.h>
20 #include <linux/module.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/slab.h>
30 #include <linux/user.h>
31 #include <linux/elf.h>
32 #include <linux/init.h>
33 #include <linux/init_task.h>
34 #include <linux/prctl.h>
35 #include <linux/ptrace.h>
36 #include <linux/kallsyms.h>
37 #include <linux/version.h>
39 #include <asm/pgtable.h>
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
43 #include <asm/processor.h>
45 #include <asm/mmu_context.h>
47 #include <asm/ppcdebug.h>
48 #include <asm/machdep.h>
49 #include <asm/iSeries/HvCallHpt.h>
50 #include <asm/hardirq.h>
51 #include <asm/cputable.h>
52 #include <asm/sections.h>
53 #include <asm/tlbflush.h>
56 struct task_struct
*last_task_used_math
= NULL
;
57 struct task_struct
*last_task_used_altivec
= NULL
;
60 struct mm_struct ioremap_mm
= {
62 .mm_users
= ATOMIC_INIT(2),
63 .mm_count
= ATOMIC_INIT(1),
64 .cpu_vm_mask
= CPU_MASK_ALL
,
65 .page_table_lock
= SPIN_LOCK_UNLOCKED
,
68 void enable_kernel_fp(void)
71 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_FP
))
74 giveup_fpu(NULL
); /* just enables FP for kernel */
76 giveup_fpu(last_task_used_math
);
77 #endif /* CONFIG_SMP */
79 EXPORT_SYMBOL(enable_kernel_fp
);
81 int dump_task_fpu(struct task_struct
*tsk
, elf_fpregset_t
*fpregs
)
83 struct pt_regs
*regs
= tsk
->thread
.regs
;
87 if (tsk
== current
&& (regs
->msr
& MSR_FP
))
90 memcpy(fpregs
, &tsk
->thread
.fpr
[0], sizeof(*fpregs
));
97 void enable_kernel_altivec(void)
100 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_VEC
))
101 giveup_altivec(current
);
103 giveup_altivec(NULL
); /* just enables FP for kernel */
105 giveup_altivec(last_task_used_altivec
);
106 #endif /* CONFIG_SMP */
108 EXPORT_SYMBOL(enable_kernel_altivec
);
110 int dump_task_altivec(struct pt_regs
*regs
, elf_vrregset_t
*vrregs
)
112 if (regs
->msr
& MSR_VEC
)
113 giveup_altivec(current
);
114 memcpy(vrregs
, ¤t
->thread
.vr
[0], sizeof(*vrregs
));
118 #endif /* CONFIG_ALTIVEC */
120 struct task_struct
*__switch_to(struct task_struct
*prev
,
121 struct task_struct
*new)
123 struct thread_struct
*new_thread
, *old_thread
;
125 struct task_struct
*last
;
128 /* avoid complexity of lazy save/restore of fpu
129 * by just saving it every time we switch out if
130 * this task used the fpu during the last quantum.
132 * If it tries to use the fpu again, it'll trap and
133 * reload its fp regs. So we don't have to do a restore
134 * every switch, just a save.
137 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_FP
))
139 #ifdef CONFIG_ALTIVEC
140 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_VEC
))
141 giveup_altivec(prev
);
142 #endif /* CONFIG_ALTIVEC */
143 #endif /* CONFIG_SMP */
145 #if defined(CONFIG_ALTIVEC) && !defined(CONFIG_SMP)
146 /* Avoid the trap. On smp this this never happens since
147 * we don't set last_task_used_altivec -- Cort
149 if (new->thread
.regs
&& last_task_used_altivec
== new)
150 new->thread
.regs
->msr
|= MSR_VEC
;
151 #endif /* CONFIG_ALTIVEC */
155 new_thread
= &new->thread
;
156 old_thread
= ¤t
->thread
;
158 local_irq_save(flags
);
159 last
= _switch(old_thread
, new_thread
);
161 local_irq_restore(flags
);
166 void show_regs(struct pt_regs
* regs
)
170 printk("NIP: %016lX XER: %016lX LR: %016lX\n",
171 regs
->nip
, regs
->xer
, regs
->link
);
172 printk("REGS: %p TRAP: %04lx %s (%s)\n",
173 regs
, regs
->trap
, print_tainted(), UTS_RELEASE
);
174 printk("MSR: %016lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
175 regs
->msr
, regs
->msr
&MSR_EE
? 1 : 0, regs
->msr
&MSR_PR
? 1 : 0,
176 regs
->msr
& MSR_FP
? 1 : 0,regs
->msr
&MSR_ME
? 1 : 0,
177 regs
->msr
&MSR_IR
? 1 : 0,
178 regs
->msr
&MSR_DR
? 1 : 0);
179 if (regs
->trap
== 0x300 || regs
->trap
== 0x380 || regs
->trap
== 0x600)
180 printk("DAR: %016lx, DSISR: %016lx\n", regs
->dar
, regs
->dsisr
);
181 printk("TASK: %p[%d] '%s' THREAD: %p",
182 current
, current
->pid
, current
->comm
, current
->thread_info
);
185 printk(" CPU: %d", smp_processor_id());
186 #endif /* CONFIG_SMP */
188 for (i
= 0; i
< 32; i
++) {
190 printk("\n" KERN_INFO
"GPR%02d: ", i
);
193 printk("%016lX ", regs
->gpr
[i
]);
197 * Lookup NIP late so we have the best change of getting the
198 * above info out without failing
200 printk("NIP [%016lx] ", regs
->nip
);
201 print_symbol("%s\n", regs
->nip
);
202 printk("LR [%016lx] ", regs
->link
);
203 print_symbol("%s\n", regs
->link
);
204 show_stack(current
, (unsigned long *)regs
->gpr
[1]);
207 void exit_thread(void)
210 if (last_task_used_math
== current
)
211 last_task_used_math
= NULL
;
212 #ifdef CONFIG_ALTIVEC
213 if (last_task_used_altivec
== current
)
214 last_task_used_altivec
= NULL
;
215 #endif /* CONFIG_ALTIVEC */
216 #endif /* CONFIG_SMP */
219 void flush_thread(void)
221 struct thread_info
*t
= current_thread_info();
223 if (t
->flags
& _TIF_ABI_PENDING
)
224 t
->flags
^= (_TIF_ABI_PENDING
| _TIF_32BIT
);
227 if (last_task_used_math
== current
)
228 last_task_used_math
= NULL
;
229 #ifdef CONFIG_ALTIVEC
230 if (last_task_used_altivec
== current
)
231 last_task_used_altivec
= NULL
;
232 #endif /* CONFIG_ALTIVEC */
233 #endif /* CONFIG_SMP */
237 release_thread(struct task_struct
*t
)
243 * This gets called before we allocate a new thread and copy
244 * the current task into it.
246 void prepare_to_copy(struct task_struct
*tsk
)
248 struct pt_regs
*regs
= tsk
->thread
.regs
;
252 if (regs
->msr
& MSR_FP
)
254 #ifdef CONFIG_ALTIVEC
255 if (regs
->msr
& MSR_VEC
)
256 giveup_altivec(current
);
257 #endif /* CONFIG_ALTIVEC */
264 copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
265 unsigned long unused
, struct task_struct
*p
, struct pt_regs
*regs
)
267 struct pt_regs
*childregs
, *kregs
;
268 extern void ret_from_fork(void);
269 unsigned long sp
= (unsigned long)p
->thread_info
+ THREAD_SIZE
;
271 p
->set_child_tid
= p
->clear_child_tid
= NULL
;
274 sp
-= sizeof(struct pt_regs
);
275 childregs
= (struct pt_regs
*) sp
;
277 if ((childregs
->msr
& MSR_PR
) == 0) {
278 /* for kernel thread, set stackptr in new task */
279 childregs
->gpr
[1] = sp
+ sizeof(struct pt_regs
);
280 p
->thread
.regs
= NULL
; /* no user register state */
281 clear_ti_thread_flag(p
->thread_info
, TIF_32BIT
);
282 #ifdef CONFIG_PPC_ISERIES
283 set_ti_thread_flag(p
->thread_info
, TIF_RUN_LIGHT
);
286 childregs
->gpr
[1] = usp
;
287 p
->thread
.regs
= childregs
;
288 if (clone_flags
& CLONE_SETTLS
) {
289 if (test_thread_flag(TIF_32BIT
))
290 childregs
->gpr
[2] = childregs
->gpr
[6];
292 childregs
->gpr
[13] = childregs
->gpr
[6];
295 childregs
->gpr
[3] = 0; /* Result from fork() */
296 sp
-= STACK_FRAME_OVERHEAD
;
299 * The way this works is that at some point in the future
300 * some task will call _switch to switch to the new task.
301 * That will pop off the stack frame created below and start
302 * the new task running at ret_from_fork. The new task will
303 * do some house keeping and then return from the fork or clone
304 * system call, using the stack frame created above.
306 sp
-= sizeof(struct pt_regs
);
307 kregs
= (struct pt_regs
*) sp
;
308 sp
-= STACK_FRAME_OVERHEAD
;
312 * The PPC64 ABI makes use of a TOC to contain function
313 * pointers. The function (ret_from_except) is actually a pointer
314 * to the TOC entry. The first entry is a pointer to the actual
317 kregs
->nip
= *((unsigned long *)ret_from_fork
);
323 * Set up a thread for executing a new program
325 void start_thread(struct pt_regs
*regs
, unsigned long fdptr
, unsigned long sp
)
327 unsigned long entry
, toc
, load_addr
= regs
->gpr
[2];
329 /* fdptr is a relocated pointer to the function descriptor for
330 * the elf _start routine. The first entry in the function
331 * descriptor is the entry address of _start and the second
332 * entry is the TOC value we need to use.
335 __get_user(entry
, (unsigned long *)fdptr
);
336 __get_user(toc
, (unsigned long *)fdptr
+1);
338 /* Check whether the e_entry function descriptor entries
339 * need to be relocated before we can use them.
341 if ( load_addr
!= 0 ) {
349 regs
->msr
= MSR_USER64
;
351 if (last_task_used_math
== current
)
352 last_task_used_math
= 0;
353 #endif /* CONFIG_SMP */
354 memset(current
->thread
.fpr
, 0, sizeof(current
->thread
.fpr
));
355 current
->thread
.fpscr
= 0;
356 #ifdef CONFIG_ALTIVEC
358 if (last_task_used_altivec
== current
)
359 last_task_used_altivec
= 0;
360 #endif /* CONFIG_SMP */
361 memset(current
->thread
.vr
, 0, sizeof(current
->thread
.vr
));
362 current
->thread
.vscr
.u
[0] = 0;
363 current
->thread
.vscr
.u
[1] = 0;
364 current
->thread
.vscr
.u
[2] = 0;
365 current
->thread
.vscr
.u
[3] = 0x00010000; /* Java mode disabled */
366 current
->thread
.vrsave
= 0;
367 current
->thread
.used_vr
= 0;
368 #endif /* CONFIG_ALTIVEC */
371 int set_fpexc_mode(struct task_struct
*tsk
, unsigned int val
)
373 struct pt_regs
*regs
= tsk
->thread
.regs
;
375 if (val
> PR_FP_EXC_PRECISE
)
377 tsk
->thread
.fpexc_mode
= __pack_fe01(val
);
378 if (regs
!= NULL
&& (regs
->msr
& MSR_FP
) != 0)
379 regs
->msr
= (regs
->msr
& ~(MSR_FE0
|MSR_FE1
))
380 | tsk
->thread
.fpexc_mode
;
384 int get_fpexc_mode(struct task_struct
*tsk
, unsigned long adr
)
388 val
= __unpack_fe01(tsk
->thread
.fpexc_mode
);
389 return put_user(val
, (unsigned int *) adr
);
392 int sys_clone(unsigned long clone_flags
, unsigned long p2
, unsigned long p3
,
393 unsigned long p4
, unsigned long p5
, unsigned long p6
,
394 struct pt_regs
*regs
)
396 unsigned long parent_tidptr
= 0;
397 unsigned long child_tidptr
= 0;
400 p2
= regs
->gpr
[1]; /* stack pointer for child */
402 if (clone_flags
& (CLONE_PARENT_SETTID
| CLONE_CHILD_SETTID
|
403 CLONE_CHILD_CLEARTID
)) {
406 if (test_thread_flag(TIF_32BIT
)) {
407 parent_tidptr
&= 0xffffffff;
408 child_tidptr
&= 0xffffffff;
412 return do_fork(clone_flags
& ~CLONE_IDLETASK
, p2
, regs
, 0,
413 (int __user
*)parent_tidptr
, (int __user
*)child_tidptr
);
416 int sys_fork(unsigned long p1
, unsigned long p2
, unsigned long p3
,
417 unsigned long p4
, unsigned long p5
, unsigned long p6
,
418 struct pt_regs
*regs
)
420 return do_fork(SIGCHLD
, regs
->gpr
[1], regs
, 0, NULL
, NULL
);
423 int sys_vfork(unsigned long p1
, unsigned long p2
, unsigned long p3
,
424 unsigned long p4
, unsigned long p5
, unsigned long p6
,
425 struct pt_regs
*regs
)
427 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->gpr
[1], regs
, 0,
431 int sys_execve(unsigned long a0
, unsigned long a1
, unsigned long a2
,
432 unsigned long a3
, unsigned long a4
, unsigned long a5
,
433 struct pt_regs
*regs
)
438 filename
= getname((char __user
*) a0
);
439 error
= PTR_ERR(filename
);
440 if (IS_ERR(filename
))
442 if (regs
->msr
& MSR_FP
)
444 #ifdef CONFIG_ALTIVEC
445 if (regs
->msr
& MSR_VEC
)
446 giveup_altivec(current
);
447 #endif /* CONFIG_ALTIVEC */
448 error
= do_execve(filename
, (char __user
* __user
*) a1
,
449 (char __user
* __user
*) a2
, regs
);
452 current
->ptrace
&= ~PT_DTRACE
;
459 static int kstack_depth_to_print
= 64;
461 static int validate_sp(unsigned long sp
, struct task_struct
*p
,
462 unsigned long nbytes
)
464 unsigned long stack_page
= (unsigned long)p
->thread_info
;
466 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
467 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
470 #ifdef CONFIG_IRQSTACKS
471 stack_page
= (unsigned long) hardirq_ctx
[task_cpu(p
)];
472 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
473 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
476 stack_page
= (unsigned long) softirq_ctx
[task_cpu(p
)];
477 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
478 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
485 unsigned long get_wchan(struct task_struct
*p
)
487 unsigned long ip
, sp
;
490 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
494 if (!validate_sp(sp
, p
, 112))
498 sp
= *(unsigned long *)sp
;
499 if (!validate_sp(sp
, p
, 112))
502 ip
= *(unsigned long *)(sp
+ 16);
503 if (!in_sched_functions(ip
))
506 } while (count
++ < 16);
510 void show_stack(struct task_struct
*p
, unsigned long *_sp
)
512 unsigned long ip
, newsp
, lr
;
514 unsigned long sp
= (unsigned long)_sp
;
527 printk("Call Trace:\n");
529 if (!validate_sp(sp
, p
, 112))
532 _sp
= (unsigned long *) sp
;
535 if (!firstframe
|| ip
!= lr
) {
536 printk("[%016lx] [%016lx] ", sp
, ip
);
537 print_symbol("%s", ip
);
539 printk(" (unreliable)");
545 * See if this is an exception frame.
546 * We look for the "regshere" marker in the current frame.
548 if (validate_sp(sp
, p
, sizeof(struct pt_regs
) + 400)
549 && _sp
[12] == 0x7265677368657265ul
) {
550 struct pt_regs
*regs
= (struct pt_regs
*)
551 (sp
+ STACK_FRAME_OVERHEAD
);
552 printk("--- Exception: %lx", regs
->trap
);
553 print_symbol(" at %s\n", regs
->nip
);
555 print_symbol(" LR = %s\n", lr
);
560 } while (count
++ < kstack_depth_to_print
);
563 void dump_stack(void)
565 show_stack(current
, (unsigned long *)__get_SP());
567 EXPORT_SYMBOL(dump_stack
);