6334a4c54c7cefeff3a5f2e7b03a37c81839b805
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 <linux/reboot.h>
21 #include <asm/uaccess.h>
22 #include <asm/mmu_context.h>
23 #include <asm/pgalloc.h>
24 #include <asm/system.h>
27 static int hlt_counter
;
30 void (*pm_idle
)(void);
31 void (*pm_power_off
)(void);
32 EXPORT_SYMBOL(pm_power_off
);
34 void disable_hlt(void)
38 EXPORT_SYMBOL(disable_hlt
);
44 EXPORT_SYMBOL(enable_hlt
);
46 static int __init
nohlt_setup(char *__unused
)
51 __setup("nohlt", nohlt_setup
);
53 static int __init
hlt_setup(char *__unused
)
58 __setup("hlt", hlt_setup
);
60 void default_idle(void)
63 clear_thread_flag(TIF_POLLING_NRFLAG
);
64 smp_mb__after_clear_bit();
66 while (!need_resched())
69 set_thread_flag(TIF_POLLING_NRFLAG
);
71 while (!need_resched())
77 set_thread_flag(TIF_POLLING_NRFLAG
);
79 /* endless idle loop with no priority at all */
81 void (*idle
)(void) = pm_idle
;
86 tick_nohz_stop_sched_tick();
87 while (!need_resched())
89 tick_nohz_restart_sched_tick();
91 preempt_enable_no_resched();
98 void machine_restart(char * __unused
)
100 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
101 asm volatile("ldc %0, sr\n\t"
102 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
105 void machine_halt(void)
113 void machine_power_off(void)
119 void show_regs(struct pt_regs
* regs
)
122 printk("Pid : %d, Comm: %20s\n", current
->pid
, current
->comm
);
123 print_symbol("PC is at %s\n", instruction_pointer(regs
));
124 printk("PC : %08lx SP : %08lx SR : %08lx ",
125 regs
->pc
, regs
->regs
[15], regs
->sr
);
127 printk("TEA : %08x ", ctrl_inl(MMU_TEA
));
131 printk("%s\n", print_tainted());
133 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
134 regs
->regs
[0],regs
->regs
[1],
135 regs
->regs
[2],regs
->regs
[3]);
136 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
137 regs
->regs
[4],regs
->regs
[5],
138 regs
->regs
[6],regs
->regs
[7]);
139 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
140 regs
->regs
[8],regs
->regs
[9],
141 regs
->regs
[10],regs
->regs
[11]);
142 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
143 regs
->regs
[12],regs
->regs
[13],
145 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
146 regs
->mach
, regs
->macl
, regs
->gbr
, regs
->pr
);
148 show_trace(NULL
, (unsigned long *)regs
->regs
[15], regs
);
152 * Create a kernel thread
156 * This is the mechanism for creating a new kernel thread.
159 extern void kernel_thread_helper(void);
161 "kernel_thread_helper:\n\t"
170 /* Don't use this in BL=1(cli). Or else, CPU resets! */
171 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
175 memset(®s
, 0, sizeof(regs
));
176 regs
.regs
[4] = (unsigned long)arg
;
177 regs
.regs
[5] = (unsigned long)fn
;
179 regs
.pc
= (unsigned long)kernel_thread_helper
;
182 /* Ok, create the new process.. */
183 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0,
184 ®s
, 0, NULL
, NULL
);
188 * Free current thread data structures etc..
190 void exit_thread(void)
192 if (current
->thread
.ubc_pc
) {
193 current
->thread
.ubc_pc
= 0;
198 void flush_thread(void)
200 #if defined(CONFIG_SH_FPU)
201 struct task_struct
*tsk
= current
;
202 /* Forget lazy FPU state */
203 clear_fpu(tsk
, task_pt_regs(tsk
));
208 void release_thread(struct task_struct
*dead_task
)
213 /* Fill in the fpu structure for a core dump.. */
214 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*fpu
)
218 #if defined(CONFIG_SH_FPU)
219 struct task_struct
*tsk
= current
;
221 fpvalid
= !!tsk_used_math(tsk
);
223 unlazy_fpu(tsk
, regs
);
224 memcpy(fpu
, &tsk
->thread
.fpu
.hard
, sizeof(*fpu
));
232 * Capture the user space registers if the task is not running (in user space)
234 int dump_task_regs(struct task_struct
*tsk
, elf_gregset_t
*regs
)
236 struct pt_regs ptregs
;
238 ptregs
= *task_pt_regs(tsk
);
239 elf_core_copy_regs(regs
, &ptregs
);
244 int dump_task_fpu(struct task_struct
*tsk
, elf_fpregset_t
*fpu
)
248 #if defined(CONFIG_SH_FPU)
249 fpvalid
= !!tsk_used_math(tsk
);
251 unlazy_fpu(tsk
, task_pt_regs(tsk
));
252 memcpy(fpu
, &tsk
->thread
.fpu
.hard
, sizeof(*fpu
));
259 asmlinkage
void ret_from_fork(void);
261 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
262 unsigned long unused
,
263 struct task_struct
*p
, struct pt_regs
*regs
)
265 struct thread_info
*ti
= task_thread_info(p
);
266 struct pt_regs
*childregs
;
267 #if defined(CONFIG_SH_FPU)
268 struct task_struct
*tsk
= current
;
270 unlazy_fpu(tsk
, regs
);
271 p
->thread
.fpu
= tsk
->thread
.fpu
;
272 copy_to_stopped_child_used_math(p
);
275 childregs
= task_pt_regs(p
);
278 if (user_mode(regs
)) {
279 childregs
->regs
[15] = usp
;
280 ti
->addr_limit
= USER_DS
;
282 childregs
->regs
[15] = (unsigned long)childregs
;
283 ti
->addr_limit
= KERNEL_DS
;
286 if (clone_flags
& CLONE_SETTLS
)
287 childregs
->gbr
= childregs
->regs
[0];
289 childregs
->regs
[0] = 0; /* Set return value for child */
291 p
->thread
.sp
= (unsigned long) childregs
;
292 p
->thread
.pc
= (unsigned long) ret_from_fork
;
294 p
->thread
.ubc_pc
= 0;
299 /* Tracing by user break controller. */
300 static void ubc_set_tracing(int asid
, unsigned long pc
)
302 #if defined(CONFIG_CPU_SH4A)
305 val
= (UBC_CBR_ID_INST
| UBC_CBR_RW_READ
| UBC_CBR_CE
);
306 val
|= (UBC_CBR_AIE
| UBC_CBR_AIV_SET(asid
));
308 ctrl_outl(val
, UBC_CBR0
);
309 ctrl_outl(pc
, UBC_CAR0
);
310 ctrl_outl(0x0, UBC_CAMR0
);
311 ctrl_outl(0x0, UBC_CBCR
);
313 val
= (UBC_CRR_RES
| UBC_CRR_PCB
| UBC_CRR_BIE
);
314 ctrl_outl(val
, UBC_CRR0
);
316 /* Read UBC register that we wrote last, for checking update */
317 val
= ctrl_inl(UBC_CRR0
);
319 #else /* CONFIG_CPU_SH4A */
320 ctrl_outl(pc
, UBC_BARA
);
323 ctrl_outb(asid
, UBC_BASRA
);
326 ctrl_outl(0, UBC_BAMRA
);
328 if (current_cpu_data
.type
== CPU_SH7729
||
329 current_cpu_data
.type
== CPU_SH7710
||
330 current_cpu_data
.type
== CPU_SH7712
) {
331 ctrl_outw(BBR_INST
| BBR_READ
| BBR_CPU
, UBC_BBRA
);
332 ctrl_outl(BRCR_PCBA
| BRCR_PCTE
, UBC_BRCR
);
334 ctrl_outw(BBR_INST
| BBR_READ
, UBC_BBRA
);
335 ctrl_outw(BRCR_PCBA
, UBC_BRCR
);
337 #endif /* CONFIG_CPU_SH4A */
341 * switch_to(x,y) should switch tasks from x to y.
344 struct task_struct
*__switch_to(struct task_struct
*prev
,
345 struct task_struct
*next
)
347 #if defined(CONFIG_SH_FPU)
348 unlazy_fpu(prev
, task_pt_regs(prev
));
351 #ifdef CONFIG_PREEMPT
354 struct pt_regs
*regs
;
356 local_irq_save(flags
);
357 regs
= task_pt_regs(prev
);
358 if (user_mode(regs
) && regs
->regs
[15] >= 0xc0000000) {
359 int offset
= (int)regs
->regs
[15];
361 /* Reset stack pointer: clear critical region mark */
362 regs
->regs
[15] = regs
->regs
[1];
363 if (regs
->pc
< regs
->regs
[0])
364 /* Go to rewind point */
365 regs
->pc
= regs
->regs
[0] + offset
;
367 local_irq_restore(flags
);
373 * Restore the kernel mode register
376 asm volatile("ldc %0, r7_bank"
378 : "r" (task_thread_info(next
)));
381 /* If no tasks are using the UBC, we're done */
382 if (ubc_usercnt
== 0)
383 /* If no tasks are using the UBC, we're done */;
384 else if (next
->thread
.ubc_pc
&& next
->mm
) {
387 asid
|= cpu_asid(smp_processor_id(), next
->mm
);
389 ubc_set_tracing(asid
, next
->thread
.ubc_pc
);
391 #if defined(CONFIG_CPU_SH4A)
392 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
393 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
395 ctrl_outw(0, UBC_BBRA
);
396 ctrl_outw(0, UBC_BBRB
);
403 asmlinkage
int sys_fork(unsigned long r4
, unsigned long r5
,
404 unsigned long r6
, unsigned long r7
,
405 struct pt_regs __regs
)
408 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
409 return do_fork(SIGCHLD
, regs
->regs
[15], regs
, 0, NULL
, NULL
);
411 /* fork almost works, enough to trick you into looking elsewhere :-( */
416 asmlinkage
int sys_clone(unsigned long clone_flags
, unsigned long newsp
,
417 unsigned long parent_tidptr
,
418 unsigned long child_tidptr
,
419 struct pt_regs __regs
)
421 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
423 newsp
= regs
->regs
[15];
424 return do_fork(clone_flags
, newsp
, regs
, 0,
425 (int __user
*)parent_tidptr
,
426 (int __user
*)child_tidptr
);
430 * This is trivial, and on the face of it looks like it
431 * could equally well be done in user mode.
433 * Not so, for quite unobvious reasons - register pressure.
434 * In user mode vfork() cannot have a stack frame, and if
435 * done by calling the "clone()" system call directly, you
436 * do not have enough call-clobbered registers to hold all
437 * the information you need.
439 asmlinkage
int sys_vfork(unsigned long r4
, unsigned long r5
,
440 unsigned long r6
, unsigned long r7
,
441 struct pt_regs __regs
)
443 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
444 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->regs
[15], regs
,
449 * sys_execve() executes a new program.
451 asmlinkage
int sys_execve(char __user
*ufilename
, char __user
* __user
*uargv
,
452 char __user
* __user
*uenvp
, unsigned long r7
,
453 struct pt_regs __regs
)
455 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
459 filename
= getname(ufilename
);
460 error
= PTR_ERR(filename
);
461 if (IS_ERR(filename
))
464 error
= do_execve(filename
, uargv
, uenvp
, regs
);
467 current
->ptrace
&= ~PT_DTRACE
;
468 task_unlock(current
);
475 unsigned long get_wchan(struct task_struct
*p
)
477 unsigned long schedule_frame
;
480 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
484 * The same comment as on the Alpha applies here, too ...
486 pc
= thread_saved_pc(p
);
487 if (in_sched_functions(pc
)) {
488 schedule_frame
= (unsigned long)p
->thread
.sp
;
489 return ((unsigned long *)schedule_frame
)[21];
495 asmlinkage
void break_point_trap(void)
498 #if defined(CONFIG_CPU_SH4A)
499 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
500 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
502 ctrl_outw(0, UBC_BBRA
);
503 ctrl_outw(0, UBC_BBRB
);
505 current
->thread
.ubc_pc
= 0;
508 force_sig(SIGTRAP
, current
);
512 * Generic trap handler.
514 asmlinkage
void debug_trap_handler(unsigned long r4
, unsigned long r5
,
515 unsigned long r6
, unsigned long r7
,
516 struct pt_regs __regs
)
518 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
521 regs
->pc
-= instruction_size(ctrl_inw(regs
->pc
- 4));
523 if (notify_die(DIE_TRAP
, "debug trap", regs
, 0, regs
->tra
& 0xff,
524 SIGTRAP
) == NOTIFY_STOP
)
527 force_sig(SIGTRAP
, current
);
531 * Special handler for BUG() traps.
533 asmlinkage
void bug_trap_handler(unsigned long r4
, unsigned long r5
,
534 unsigned long r6
, unsigned long r7
,
535 struct pt_regs __regs
)
537 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
540 regs
->pc
-= instruction_size(ctrl_inw(regs
->pc
- 4));
542 if (notify_die(DIE_TRAP
, "bug trap", regs
, 0, TRAPA_BUG_OPCODE
& 0xff,
543 SIGTRAP
) == NOTIFY_STOP
)
547 if (__kernel_text_address(instruction_pointer(regs
))) {
548 u16 insn
= *(u16
*)instruction_pointer(regs
);
549 if (insn
== TRAPA_BUG_OPCODE
)
554 force_sig(SIGTRAP
, current
);
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