2 * arch/sh/kernel/process.c
4 * This file handles the architecture-dependent parts of process handling..
6 * Copyright (C) 1995 Linus Torvalds
8 * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima
9 * Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
10 * Copyright (C) 2002 - 2007 Paul Mundt
12 #include <linux/module.h>
14 #include <linux/elfcore.h>
16 #include <linux/kallsyms.h>
17 #include <linux/kexec.h>
18 #include <linux/kdebug.h>
19 #include <linux/tick.h>
20 #include <asm/uaccess.h>
21 #include <asm/mmu_context.h>
22 #include <asm/pgalloc.h>
23 #include <asm/system.h>
26 static int hlt_counter
;
29 void (*pm_idle
)(void);
30 void (*pm_power_off
)(void);
31 EXPORT_SYMBOL(pm_power_off
);
33 void disable_hlt(void)
37 EXPORT_SYMBOL(disable_hlt
);
43 EXPORT_SYMBOL(enable_hlt
);
45 static int __init
nohlt_setup(char *__unused
)
50 __setup("nohlt", nohlt_setup
);
52 static int __init
hlt_setup(char *__unused
)
57 __setup("hlt", hlt_setup
);
59 void default_idle(void)
62 clear_thread_flag(TIF_POLLING_NRFLAG
);
63 smp_mb__after_clear_bit();
65 while (!need_resched())
68 set_thread_flag(TIF_POLLING_NRFLAG
);
70 while (!need_resched())
76 set_thread_flag(TIF_POLLING_NRFLAG
);
78 /* endless idle loop with no priority at all */
80 void (*idle
)(void) = pm_idle
;
85 tick_nohz_stop_sched_tick();
86 while (!need_resched())
88 tick_nohz_restart_sched_tick();
90 preempt_enable_no_resched();
97 void machine_restart(char * __unused
)
99 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
100 asm volatile("ldc %0, sr\n\t"
101 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
104 void machine_halt(void)
112 void machine_power_off(void)
118 void show_regs(struct pt_regs
* regs
)
121 printk("Pid : %d, Comm: %20s\n", current
->pid
, current
->comm
);
122 print_symbol("PC is at %s\n", instruction_pointer(regs
));
123 printk("PC : %08lx SP : %08lx SR : %08lx ",
124 regs
->pc
, regs
->regs
[15], regs
->sr
);
126 printk("TEA : %08x ", ctrl_inl(MMU_TEA
));
130 printk("%s\n", print_tainted());
132 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
133 regs
->regs
[0],regs
->regs
[1],
134 regs
->regs
[2],regs
->regs
[3]);
135 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
136 regs
->regs
[4],regs
->regs
[5],
137 regs
->regs
[6],regs
->regs
[7]);
138 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
139 regs
->regs
[8],regs
->regs
[9],
140 regs
->regs
[10],regs
->regs
[11]);
141 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
142 regs
->regs
[12],regs
->regs
[13],
144 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
145 regs
->mach
, regs
->macl
, regs
->gbr
, regs
->pr
);
147 show_trace(NULL
, (unsigned long *)regs
->regs
[15], regs
);
151 * Create a kernel thread
155 * This is the mechanism for creating a new kernel thread.
158 extern void kernel_thread_helper(void);
160 "kernel_thread_helper:\n\t"
169 /* Don't use this in BL=1(cli). Or else, CPU resets! */
170 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
174 memset(®s
, 0, sizeof(regs
));
175 regs
.regs
[4] = (unsigned long)arg
;
176 regs
.regs
[5] = (unsigned long)fn
;
178 regs
.pc
= (unsigned long)kernel_thread_helper
;
181 /* Ok, create the new process.. */
182 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0,
183 ®s
, 0, NULL
, NULL
);
187 * Free current thread data structures etc..
189 void exit_thread(void)
191 if (current
->thread
.ubc_pc
) {
192 current
->thread
.ubc_pc
= 0;
197 void flush_thread(void)
199 #if defined(CONFIG_SH_FPU)
200 struct task_struct
*tsk
= current
;
201 /* Forget lazy FPU state */
202 clear_fpu(tsk
, task_pt_regs(tsk
));
207 void release_thread(struct task_struct
*dead_task
)
212 /* Fill in the fpu structure for a core dump.. */
213 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*fpu
)
217 #if defined(CONFIG_SH_FPU)
218 struct task_struct
*tsk
= current
;
220 fpvalid
= !!tsk_used_math(tsk
);
222 unlazy_fpu(tsk
, regs
);
223 memcpy(fpu
, &tsk
->thread
.fpu
.hard
, sizeof(*fpu
));
231 * Capture the user space registers if the task is not running (in user space)
233 int dump_task_regs(struct task_struct
*tsk
, elf_gregset_t
*regs
)
235 struct pt_regs ptregs
;
237 ptregs
= *task_pt_regs(tsk
);
238 elf_core_copy_regs(regs
, &ptregs
);
243 int dump_task_fpu(struct task_struct
*tsk
, elf_fpregset_t
*fpu
)
247 #if defined(CONFIG_SH_FPU)
248 fpvalid
= !!tsk_used_math(tsk
);
250 unlazy_fpu(tsk
, task_pt_regs(tsk
));
251 memcpy(fpu
, &tsk
->thread
.fpu
.hard
, sizeof(*fpu
));
258 asmlinkage
void ret_from_fork(void);
260 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
261 unsigned long unused
,
262 struct task_struct
*p
, struct pt_regs
*regs
)
264 struct thread_info
*ti
= task_thread_info(p
);
265 struct pt_regs
*childregs
;
266 #if defined(CONFIG_SH_FPU)
267 struct task_struct
*tsk
= current
;
269 unlazy_fpu(tsk
, regs
);
270 p
->thread
.fpu
= tsk
->thread
.fpu
;
271 copy_to_stopped_child_used_math(p
);
274 childregs
= task_pt_regs(p
);
277 if (user_mode(regs
)) {
278 childregs
->regs
[15] = usp
;
279 ti
->addr_limit
= USER_DS
;
281 childregs
->regs
[15] = (unsigned long)childregs
;
282 ti
->addr_limit
= KERNEL_DS
;
285 if (clone_flags
& CLONE_SETTLS
)
286 childregs
->gbr
= childregs
->regs
[0];
288 childregs
->regs
[0] = 0; /* Set return value for child */
290 p
->thread
.sp
= (unsigned long) childregs
;
291 p
->thread
.pc
= (unsigned long) ret_from_fork
;
293 p
->thread
.ubc_pc
= 0;
298 /* Tracing by user break controller. */
299 static void ubc_set_tracing(int asid
, unsigned long pc
)
301 #if defined(CONFIG_CPU_SH4A)
304 val
= (UBC_CBR_ID_INST
| UBC_CBR_RW_READ
| UBC_CBR_CE
);
305 val
|= (UBC_CBR_AIE
| UBC_CBR_AIV_SET(asid
));
307 ctrl_outl(val
, UBC_CBR0
);
308 ctrl_outl(pc
, UBC_CAR0
);
309 ctrl_outl(0x0, UBC_CAMR0
);
310 ctrl_outl(0x0, UBC_CBCR
);
312 val
= (UBC_CRR_RES
| UBC_CRR_PCB
| UBC_CRR_BIE
);
313 ctrl_outl(val
, UBC_CRR0
);
315 /* Read UBC register that we wrote last, for checking update */
316 val
= ctrl_inl(UBC_CRR0
);
318 #else /* CONFIG_CPU_SH4A */
319 ctrl_outl(pc
, UBC_BARA
);
322 /* We don't have any ASID settings for the SH-2! */
323 if (current_cpu_data
.type
!= CPU_SH7604
)
324 ctrl_outb(asid
, UBC_BASRA
);
327 ctrl_outl(0, UBC_BAMRA
);
329 if (current_cpu_data
.type
== CPU_SH7729
||
330 current_cpu_data
.type
== CPU_SH7710
||
331 current_cpu_data
.type
== CPU_SH7712
) {
332 ctrl_outw(BBR_INST
| BBR_READ
| BBR_CPU
, UBC_BBRA
);
333 ctrl_outl(BRCR_PCBA
| BRCR_PCTE
, UBC_BRCR
);
335 ctrl_outw(BBR_INST
| BBR_READ
, UBC_BBRA
);
336 ctrl_outw(BRCR_PCBA
, UBC_BRCR
);
338 #endif /* CONFIG_CPU_SH4A */
342 * switch_to(x,y) should switch tasks from x to y.
345 struct task_struct
*__switch_to(struct task_struct
*prev
,
346 struct task_struct
*next
)
348 #if defined(CONFIG_SH_FPU)
349 unlazy_fpu(prev
, task_pt_regs(prev
));
352 #ifdef CONFIG_PREEMPT
355 struct pt_regs
*regs
;
357 local_irq_save(flags
);
358 regs
= task_pt_regs(prev
);
359 if (user_mode(regs
) && regs
->regs
[15] >= 0xc0000000) {
360 int offset
= (int)regs
->regs
[15];
362 /* Reset stack pointer: clear critical region mark */
363 regs
->regs
[15] = regs
->regs
[1];
364 if (regs
->pc
< regs
->regs
[0])
365 /* Go to rewind point */
366 regs
->pc
= regs
->regs
[0] + offset
;
368 local_irq_restore(flags
);
374 * Restore the kernel mode register
377 asm volatile("ldc %0, r7_bank"
379 : "r" (task_thread_info(next
)));
382 /* If no tasks are using the UBC, we're done */
383 if (ubc_usercnt
== 0)
384 /* If no tasks are using the UBC, we're done */;
385 else if (next
->thread
.ubc_pc
&& next
->mm
) {
388 asid
|= cpu_asid(smp_processor_id(), next
->mm
);
390 ubc_set_tracing(asid
, next
->thread
.ubc_pc
);
392 #if defined(CONFIG_CPU_SH4A)
393 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
394 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
396 ctrl_outw(0, UBC_BBRA
);
397 ctrl_outw(0, UBC_BBRB
);
404 asmlinkage
int sys_fork(unsigned long r4
, unsigned long r5
,
405 unsigned long r6
, unsigned long r7
,
406 struct pt_regs __regs
)
408 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
410 return do_fork(SIGCHLD
, regs
->regs
[15], regs
, 0, NULL
, NULL
);
412 /* fork almost works, enough to trick you into looking elsewhere :-( */
417 asmlinkage
int sys_clone(unsigned long clone_flags
, unsigned long newsp
,
418 unsigned long parent_tidptr
,
419 unsigned long child_tidptr
,
420 struct pt_regs __regs
)
422 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
424 newsp
= regs
->regs
[15];
425 return do_fork(clone_flags
, newsp
, regs
, 0,
426 (int __user
*)parent_tidptr
,
427 (int __user
*)child_tidptr
);
431 * This is trivial, and on the face of it looks like it
432 * could equally well be done in user mode.
434 * Not so, for quite unobvious reasons - register pressure.
435 * In user mode vfork() cannot have a stack frame, and if
436 * done by calling the "clone()" system call directly, you
437 * do not have enough call-clobbered registers to hold all
438 * the information you need.
440 asmlinkage
int sys_vfork(unsigned long r4
, unsigned long r5
,
441 unsigned long r6
, unsigned long r7
,
442 struct pt_regs __regs
)
444 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
445 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->regs
[15], regs
,
450 * sys_execve() executes a new program.
452 asmlinkage
int sys_execve(char *ufilename
, char **uargv
,
453 char **uenvp
, unsigned long r7
,
454 struct pt_regs __regs
)
456 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
460 filename
= getname((char __user
*)ufilename
);
461 error
= PTR_ERR(filename
);
462 if (IS_ERR(filename
))
465 error
= do_execve(filename
,
466 (char __user
* __user
*)uargv
,
467 (char __user
* __user
*)uenvp
,
471 current
->ptrace
&= ~PT_DTRACE
;
472 task_unlock(current
);
479 unsigned long get_wchan(struct task_struct
*p
)
481 unsigned long schedule_frame
;
484 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
488 * The same comment as on the Alpha applies here, too ...
490 pc
= thread_saved_pc(p
);
491 if (in_sched_functions(pc
)) {
492 schedule_frame
= (unsigned long)p
->thread
.sp
;
493 return ((unsigned long *)schedule_frame
)[21];
499 asmlinkage
void break_point_trap(void)
502 #if defined(CONFIG_CPU_SH4A)
503 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
504 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
506 ctrl_outw(0, UBC_BBRA
);
507 ctrl_outw(0, UBC_BBRB
);
509 current
->thread
.ubc_pc
= 0;
512 force_sig(SIGTRAP
, current
);
516 * Generic trap handler.
518 asmlinkage
void debug_trap_handler(unsigned long r4
, unsigned long r5
,
519 unsigned long r6
, unsigned long r7
,
520 struct pt_regs __regs
)
522 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
525 regs
->pc
-= instruction_size(ctrl_inw(regs
->pc
- 4));
527 if (notify_die(DIE_TRAP
, "debug trap", regs
, 0, regs
->tra
& 0xff,
528 SIGTRAP
) == NOTIFY_STOP
)
531 force_sig(SIGTRAP
, current
);
535 * Special handler for BUG() traps.
537 asmlinkage
void bug_trap_handler(unsigned long r4
, unsigned long r5
,
538 unsigned long r6
, unsigned long r7
,
539 struct pt_regs __regs
)
541 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
544 regs
->pc
-= instruction_size(ctrl_inw(regs
->pc
- 4));
546 if (notify_die(DIE_TRAP
, "bug trap", regs
, 0, TRAPA_BUG_OPCODE
& 0xff,
547 SIGTRAP
) == NOTIFY_STOP
)
551 if (__kernel_text_address(instruction_pointer(regs
))) {
552 u16 insn
= *(u16
*)instruction_pointer(regs
);
553 if (insn
== TRAPA_BUG_OPCODE
)
558 force_sig(SIGTRAP
, current
);