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 <asm/kdebug.h>
19 #include <asm/uaccess.h>
20 #include <asm/mmu_context.h>
23 static int hlt_counter
;
26 #define HARD_IDLE_TIMEOUT (HZ / 3)
28 void (*pm_idle
)(void);
29 void (*pm_power_off
)(void);
30 EXPORT_SYMBOL(pm_power_off
);
32 void disable_hlt(void)
36 EXPORT_SYMBOL(disable_hlt
);
42 EXPORT_SYMBOL(enable_hlt
);
44 void default_idle(void)
54 /* endless idle loop with no priority at all */
56 void (*idle
)(void) = pm_idle
;
61 while (!need_resched())
64 preempt_enable_no_resched();
70 void machine_restart(char * __unused
)
72 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
73 asm volatile("ldc %0, sr\n\t"
74 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
77 void machine_halt(void)
85 void machine_power_off(void)
91 void show_regs(struct pt_regs
* regs
)
94 printk("Pid : %d, Comm: %20s\n", current
->pid
, current
->comm
);
95 print_symbol("PC is at %s\n", instruction_pointer(regs
));
96 printk("PC : %08lx SP : %08lx SR : %08lx ",
97 regs
->pc
, regs
->regs
[15], regs
->sr
);
99 printk("TEA : %08x ", ctrl_inl(MMU_TEA
));
103 printk("%s\n", print_tainted());
105 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
106 regs
->regs
[0],regs
->regs
[1],
107 regs
->regs
[2],regs
->regs
[3]);
108 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
109 regs
->regs
[4],regs
->regs
[5],
110 regs
->regs
[6],regs
->regs
[7]);
111 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
112 regs
->regs
[8],regs
->regs
[9],
113 regs
->regs
[10],regs
->regs
[11]);
114 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
115 regs
->regs
[12],regs
->regs
[13],
117 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
118 regs
->mach
, regs
->macl
, regs
->gbr
, regs
->pr
);
120 show_trace(NULL
, (unsigned long *)regs
->regs
[15], regs
);
124 * Create a kernel thread
128 * This is the mechanism for creating a new kernel thread.
131 extern void kernel_thread_helper(void);
133 "kernel_thread_helper:\n\t"
142 /* Don't use this in BL=1(cli). Or else, CPU resets! */
143 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
147 memset(®s
, 0, sizeof(regs
));
148 regs
.regs
[4] = (unsigned long)arg
;
149 regs
.regs
[5] = (unsigned long)fn
;
151 regs
.pc
= (unsigned long)kernel_thread_helper
;
154 /* Ok, create the new process.. */
155 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0,
156 ®s
, 0, NULL
, NULL
);
160 * Free current thread data structures etc..
162 void exit_thread(void)
164 if (current
->thread
.ubc_pc
) {
165 current
->thread
.ubc_pc
= 0;
170 void flush_thread(void)
172 #if defined(CONFIG_SH_FPU)
173 struct task_struct
*tsk
= current
;
174 /* Forget lazy FPU state */
175 clear_fpu(tsk
, task_pt_regs(tsk
));
180 void release_thread(struct task_struct
*dead_task
)
185 /* Fill in the fpu structure for a core dump.. */
186 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*fpu
)
190 #if defined(CONFIG_SH_FPU)
191 struct task_struct
*tsk
= current
;
193 fpvalid
= !!tsk_used_math(tsk
);
195 unlazy_fpu(tsk
, regs
);
196 memcpy(fpu
, &tsk
->thread
.fpu
.hard
, sizeof(*fpu
));
204 * Capture the user space registers if the task is not running (in user space)
206 int dump_task_regs(struct task_struct
*tsk
, elf_gregset_t
*regs
)
208 struct pt_regs ptregs
;
210 ptregs
= *task_pt_regs(tsk
);
211 elf_core_copy_regs(regs
, &ptregs
);
216 int dump_task_fpu(struct task_struct
*tsk
, elf_fpregset_t
*fpu
)
220 #if defined(CONFIG_SH_FPU)
221 fpvalid
= !!tsk_used_math(tsk
);
223 unlazy_fpu(tsk
, task_pt_regs(tsk
));
224 memcpy(fpu
, &tsk
->thread
.fpu
.hard
, sizeof(*fpu
));
231 asmlinkage
void ret_from_fork(void);
233 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
234 unsigned long unused
,
235 struct task_struct
*p
, struct pt_regs
*regs
)
237 struct thread_info
*ti
= task_thread_info(p
);
238 struct pt_regs
*childregs
;
239 #if defined(CONFIG_SH_FPU)
240 struct task_struct
*tsk
= current
;
242 unlazy_fpu(tsk
, regs
);
243 p
->thread
.fpu
= tsk
->thread
.fpu
;
244 copy_to_stopped_child_used_math(p
);
247 childregs
= task_pt_regs(p
);
250 if (user_mode(regs
)) {
251 childregs
->regs
[15] = usp
;
252 ti
->addr_limit
= USER_DS
;
254 childregs
->regs
[15] = (unsigned long)childregs
;
255 ti
->addr_limit
= KERNEL_DS
;
258 if (clone_flags
& CLONE_SETTLS
)
259 childregs
->gbr
= childregs
->regs
[0];
261 childregs
->regs
[0] = 0; /* Set return value for child */
263 p
->thread
.sp
= (unsigned long) childregs
;
264 p
->thread
.pc
= (unsigned long) ret_from_fork
;
266 p
->thread
.ubc_pc
= 0;
271 /* Tracing by user break controller. */
272 static void ubc_set_tracing(int asid
, unsigned long pc
)
274 #if defined(CONFIG_CPU_SH4A)
277 val
= (UBC_CBR_ID_INST
| UBC_CBR_RW_READ
| UBC_CBR_CE
);
278 val
|= (UBC_CBR_AIE
| UBC_CBR_AIV_SET(asid
));
280 ctrl_outl(val
, UBC_CBR0
);
281 ctrl_outl(pc
, UBC_CAR0
);
282 ctrl_outl(0x0, UBC_CAMR0
);
283 ctrl_outl(0x0, UBC_CBCR
);
285 val
= (UBC_CRR_RES
| UBC_CRR_PCB
| UBC_CRR_BIE
);
286 ctrl_outl(val
, UBC_CRR0
);
288 /* Read UBC register that we wrote last, for checking update */
289 val
= ctrl_inl(UBC_CRR0
);
291 #else /* CONFIG_CPU_SH4A */
292 ctrl_outl(pc
, UBC_BARA
);
295 /* We don't have any ASID settings for the SH-2! */
296 if (current_cpu_data
.type
!= CPU_SH7604
)
297 ctrl_outb(asid
, UBC_BASRA
);
300 ctrl_outl(0, UBC_BAMRA
);
302 if (current_cpu_data
.type
== CPU_SH7729
||
303 current_cpu_data
.type
== CPU_SH7710
||
304 current_cpu_data
.type
== CPU_SH7712
) {
305 ctrl_outw(BBR_INST
| BBR_READ
| BBR_CPU
, UBC_BBRA
);
306 ctrl_outl(BRCR_PCBA
| BRCR_PCTE
, UBC_BRCR
);
308 ctrl_outw(BBR_INST
| BBR_READ
, UBC_BBRA
);
309 ctrl_outw(BRCR_PCBA
, UBC_BRCR
);
311 #endif /* CONFIG_CPU_SH4A */
315 * switch_to(x,y) should switch tasks from x to y.
318 struct task_struct
*__switch_to(struct task_struct
*prev
,
319 struct task_struct
*next
)
321 #if defined(CONFIG_SH_FPU)
322 unlazy_fpu(prev
, task_pt_regs(prev
));
325 #ifdef CONFIG_PREEMPT
328 struct pt_regs
*regs
;
330 local_irq_save(flags
);
331 regs
= task_pt_regs(prev
);
332 if (user_mode(regs
) && regs
->regs
[15] >= 0xc0000000) {
333 int offset
= (int)regs
->regs
[15];
335 /* Reset stack pointer: clear critical region mark */
336 regs
->regs
[15] = regs
->regs
[1];
337 if (regs
->pc
< regs
->regs
[0])
338 /* Go to rewind point */
339 regs
->pc
= regs
->regs
[0] + offset
;
341 local_irq_restore(flags
);
347 * Restore the kernel mode register
350 asm volatile("ldc %0, r7_bank"
352 : "r" (task_thread_info(next
)));
355 /* If no tasks are using the UBC, we're done */
356 if (ubc_usercnt
== 0)
357 /* If no tasks are using the UBC, we're done */;
358 else if (next
->thread
.ubc_pc
&& next
->mm
) {
361 asid
|= cpu_asid(smp_processor_id(), next
->mm
);
363 ubc_set_tracing(asid
, next
->thread
.ubc_pc
);
365 #if defined(CONFIG_CPU_SH4A)
366 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
367 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
369 ctrl_outw(0, UBC_BBRA
);
370 ctrl_outw(0, UBC_BBRB
);
377 asmlinkage
int sys_fork(unsigned long r4
, unsigned long r5
,
378 unsigned long r6
, unsigned long r7
,
379 struct pt_regs __regs
)
381 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
383 return do_fork(SIGCHLD
, regs
->regs
[15], regs
, 0, NULL
, NULL
);
385 /* fork almost works, enough to trick you into looking elsewhere :-( */
390 asmlinkage
int sys_clone(unsigned long clone_flags
, unsigned long newsp
,
391 unsigned long parent_tidptr
,
392 unsigned long child_tidptr
,
393 struct pt_regs __regs
)
395 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
397 newsp
= regs
->regs
[15];
398 return do_fork(clone_flags
, newsp
, regs
, 0,
399 (int __user
*)parent_tidptr
,
400 (int __user
*)child_tidptr
);
404 * This is trivial, and on the face of it looks like it
405 * could equally well be done in user mode.
407 * Not so, for quite unobvious reasons - register pressure.
408 * In user mode vfork() cannot have a stack frame, and if
409 * done by calling the "clone()" system call directly, you
410 * do not have enough call-clobbered registers to hold all
411 * the information you need.
413 asmlinkage
int sys_vfork(unsigned long r4
, unsigned long r5
,
414 unsigned long r6
, unsigned long r7
,
415 struct pt_regs __regs
)
417 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
418 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->regs
[15], regs
,
423 * sys_execve() executes a new program.
425 asmlinkage
int sys_execve(char *ufilename
, char **uargv
,
426 char **uenvp
, unsigned long r7
,
427 struct pt_regs __regs
)
429 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
433 filename
= getname((char __user
*)ufilename
);
434 error
= PTR_ERR(filename
);
435 if (IS_ERR(filename
))
438 error
= do_execve(filename
,
439 (char __user
* __user
*)uargv
,
440 (char __user
* __user
*)uenvp
,
444 current
->ptrace
&= ~PT_DTRACE
;
445 task_unlock(current
);
452 unsigned long get_wchan(struct task_struct
*p
)
454 unsigned long schedule_frame
;
457 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
461 * The same comment as on the Alpha applies here, too ...
463 pc
= thread_saved_pc(p
);
464 if (in_sched_functions(pc
)) {
465 schedule_frame
= (unsigned long)p
->thread
.sp
;
466 return ((unsigned long *)schedule_frame
)[21];
472 asmlinkage
void break_point_trap(void)
475 #if defined(CONFIG_CPU_SH4A)
476 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
477 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
479 ctrl_outw(0, UBC_BBRA
);
480 ctrl_outw(0, UBC_BBRB
);
482 current
->thread
.ubc_pc
= 0;
485 force_sig(SIGTRAP
, current
);
489 * Generic trap handler.
491 asmlinkage
void debug_trap_handler(unsigned long r4
, unsigned long r5
,
492 unsigned long r6
, unsigned long r7
,
493 struct pt_regs __regs
)
495 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
500 if (notify_die(DIE_TRAP
, regs
, regs
->tra
& 0xff,
501 SIGTRAP
) == NOTIFY_STOP
)
504 force_sig(SIGTRAP
, current
);
508 * Special handler for BUG() traps.
510 asmlinkage
void bug_trap_handler(unsigned long r4
, unsigned long r5
,
511 unsigned long r6
, unsigned long r7
,
512 struct pt_regs __regs
)
514 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
519 if (notify_die(DIE_TRAP
, regs
, TRAPA_BUG_OPCODE
& 0xff,
520 SIGTRAP
) == NOTIFY_STOP
)
524 if (__kernel_text_address(instruction_pointer(regs
))) {
525 u16 insn
= *(u16
*)instruction_pointer(regs
);
526 if (insn
== TRAPA_BUG_OPCODE
)
531 force_sig(SIGTRAP
, current
);
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