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 - 2008 Paul Mundt
12 * This file is subject to the terms and conditions of the GNU General Public
13 * License. See the file "COPYING" in the main directory of this archive
16 #include <linux/module.h>
18 #include <linux/elfcore.h>
20 #include <linux/kallsyms.h>
21 #include <linux/kexec.h>
22 #include <linux/kdebug.h>
23 #include <linux/tick.h>
24 #include <linux/reboot.h>
26 #include <linux/preempt.h>
27 #include <asm/uaccess.h>
28 #include <asm/mmu_context.h>
29 #include <asm/pgalloc.h>
30 #include <asm/system.h>
33 #include <asm/syscalls.h>
35 static int hlt_counter
;
38 void (*pm_idle
)(void);
39 void (*pm_power_off
)(void);
40 EXPORT_SYMBOL(pm_power_off
);
42 static int __init
nohlt_setup(char *__unused
)
47 __setup("nohlt", nohlt_setup
);
49 static int __init
hlt_setup(char *__unused
)
54 __setup("hlt", hlt_setup
);
56 static void default_idle(void)
59 clear_thread_flag(TIF_POLLING_NRFLAG
);
60 smp_mb__after_clear_bit();
62 while (!need_resched())
65 set_thread_flag(TIF_POLLING_NRFLAG
);
67 while (!need_resched())
73 set_thread_flag(TIF_POLLING_NRFLAG
);
75 /* endless idle loop with no priority at all */
77 void (*idle
)(void) = pm_idle
;
82 tick_nohz_stop_sched_tick(1);
83 while (!need_resched())
85 tick_nohz_restart_sched_tick();
87 preempt_enable_no_resched();
94 void machine_restart(char * __unused
)
96 /* SR.BL=1 and invoke address error to let CPU reset (manual reset) */
97 asm volatile("ldc %0, sr\n\t"
98 "mov.l @%1, %0" : : "r" (0x10000000), "r" (0x80000001));
101 void machine_halt(void)
109 void machine_power_off(void)
115 void show_regs(struct pt_regs
* regs
)
118 printk("Pid : %d, Comm: %20s\n", task_pid_nr(current
), current
->comm
);
119 printk("CPU : %d %s (%s %.*s)\n",
120 smp_processor_id(), print_tainted(), init_utsname()->release
,
121 (int)strcspn(init_utsname()->version
, " "),
122 init_utsname()->version
);
124 print_symbol("PC is at %s\n", instruction_pointer(regs
));
125 print_symbol("PR is at %s\n", regs
->pr
);
127 printk("PC : %08lx SP : %08lx SR : %08lx ",
128 regs
->pc
, regs
->regs
[15], regs
->sr
);
130 printk("TEA : %08x\n", ctrl_inl(MMU_TEA
));
135 printk("R0 : %08lx R1 : %08lx R2 : %08lx R3 : %08lx\n",
136 regs
->regs
[0],regs
->regs
[1],
137 regs
->regs
[2],regs
->regs
[3]);
138 printk("R4 : %08lx R5 : %08lx R6 : %08lx R7 : %08lx\n",
139 regs
->regs
[4],regs
->regs
[5],
140 regs
->regs
[6],regs
->regs
[7]);
141 printk("R8 : %08lx R9 : %08lx R10 : %08lx R11 : %08lx\n",
142 regs
->regs
[8],regs
->regs
[9],
143 regs
->regs
[10],regs
->regs
[11]);
144 printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
145 regs
->regs
[12],regs
->regs
[13],
147 printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n",
148 regs
->mach
, regs
->macl
, regs
->gbr
, regs
->pr
);
150 show_trace(NULL
, (unsigned long *)regs
->regs
[15], regs
);
154 * Create a kernel thread
158 * This is the mechanism for creating a new kernel thread.
161 extern void kernel_thread_helper(void);
163 "kernel_thread_helper:\n\t"
172 /* Don't use this in BL=1(cli). Or else, CPU resets! */
173 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
178 memset(®s
, 0, sizeof(regs
));
179 regs
.regs
[4] = (unsigned long)arg
;
180 regs
.regs
[5] = (unsigned long)fn
;
182 regs
.pc
= (unsigned long)kernel_thread_helper
;
185 /* Ok, create the new process.. */
186 pid
= do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0,
187 ®s
, 0, NULL
, NULL
);
189 trace_mark(kernel_arch_kthread_create
, "pid %d fn %p", pid
, fn
);
195 * Free current thread data structures etc..
197 void exit_thread(void)
199 if (current
->thread
.ubc_pc
) {
200 current
->thread
.ubc_pc
= 0;
205 void flush_thread(void)
207 #if defined(CONFIG_SH_FPU)
208 struct task_struct
*tsk
= current
;
209 /* Forget lazy FPU state */
210 clear_fpu(tsk
, task_pt_regs(tsk
));
215 void release_thread(struct task_struct
*dead_task
)
220 /* Fill in the fpu structure for a core dump.. */
221 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*fpu
)
225 #if defined(CONFIG_SH_FPU)
226 struct task_struct
*tsk
= current
;
228 fpvalid
= !!tsk_used_math(tsk
);
230 fpvalid
= !fpregs_get(tsk
, NULL
, 0,
231 sizeof(struct user_fpu_struct
),
238 asmlinkage
void ret_from_fork(void);
240 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
241 unsigned long unused
,
242 struct task_struct
*p
, struct pt_regs
*regs
)
244 struct thread_info
*ti
= task_thread_info(p
);
245 struct pt_regs
*childregs
;
246 #if defined(CONFIG_SH_FPU)
247 struct task_struct
*tsk
= current
;
249 unlazy_fpu(tsk
, regs
);
250 p
->thread
.fpu
= tsk
->thread
.fpu
;
251 copy_to_stopped_child_used_math(p
);
254 childregs
= task_pt_regs(p
);
257 if (user_mode(regs
)) {
258 childregs
->regs
[15] = usp
;
259 ti
->addr_limit
= USER_DS
;
261 childregs
->regs
[15] = (unsigned long)childregs
;
262 ti
->addr_limit
= KERNEL_DS
;
265 if (clone_flags
& CLONE_SETTLS
)
266 childregs
->gbr
= childregs
->regs
[0];
268 childregs
->regs
[0] = 0; /* Set return value for child */
270 p
->thread
.sp
= (unsigned long) childregs
;
271 p
->thread
.pc
= (unsigned long) ret_from_fork
;
273 p
->thread
.ubc_pc
= 0;
278 /* Tracing by user break controller. */
279 static void ubc_set_tracing(int asid
, unsigned long pc
)
281 #if defined(CONFIG_CPU_SH4A)
284 val
= (UBC_CBR_ID_INST
| UBC_CBR_RW_READ
| UBC_CBR_CE
);
285 val
|= (UBC_CBR_AIE
| UBC_CBR_AIV_SET(asid
));
287 ctrl_outl(val
, UBC_CBR0
);
288 ctrl_outl(pc
, UBC_CAR0
);
289 ctrl_outl(0x0, UBC_CAMR0
);
290 ctrl_outl(0x0, UBC_CBCR
);
292 val
= (UBC_CRR_RES
| UBC_CRR_PCB
| UBC_CRR_BIE
);
293 ctrl_outl(val
, UBC_CRR0
);
295 /* Read UBC register that we wrote last, for checking update */
296 val
= ctrl_inl(UBC_CRR0
);
298 #else /* CONFIG_CPU_SH4A */
299 ctrl_outl(pc
, UBC_BARA
);
302 ctrl_outb(asid
, UBC_BASRA
);
305 ctrl_outl(0, UBC_BAMRA
);
307 if (current_cpu_data
.type
== CPU_SH7729
||
308 current_cpu_data
.type
== CPU_SH7710
||
309 current_cpu_data
.type
== CPU_SH7712
) {
310 ctrl_outw(BBR_INST
| BBR_READ
| BBR_CPU
, UBC_BBRA
);
311 ctrl_outl(BRCR_PCBA
| BRCR_PCTE
, UBC_BRCR
);
313 ctrl_outw(BBR_INST
| BBR_READ
, UBC_BBRA
);
314 ctrl_outw(BRCR_PCBA
, UBC_BRCR
);
316 #endif /* CONFIG_CPU_SH4A */
320 * switch_to(x,y) should switch tasks from x to y.
323 struct task_struct
*__switch_to(struct task_struct
*prev
,
324 struct task_struct
*next
)
326 #if defined(CONFIG_SH_FPU)
327 unlazy_fpu(prev
, task_pt_regs(prev
));
332 * Restore the kernel mode register
335 asm volatile("ldc %0, r7_bank"
337 : "r" (task_thread_info(next
)));
340 /* If no tasks are using the UBC, we're done */
341 if (ubc_usercnt
== 0)
342 /* If no tasks are using the UBC, we're done */;
343 else if (next
->thread
.ubc_pc
&& next
->mm
) {
346 asid
|= cpu_asid(smp_processor_id(), next
->mm
);
348 ubc_set_tracing(asid
, next
->thread
.ubc_pc
);
350 #if defined(CONFIG_CPU_SH4A)
351 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
352 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
354 ctrl_outw(0, UBC_BBRA
);
355 ctrl_outw(0, UBC_BBRB
);
362 asmlinkage
int sys_fork(unsigned long r4
, unsigned long r5
,
363 unsigned long r6
, unsigned long r7
,
364 struct pt_regs __regs
)
367 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
368 return do_fork(SIGCHLD
, regs
->regs
[15], regs
, 0, NULL
, NULL
);
370 /* fork almost works, enough to trick you into looking elsewhere :-( */
375 asmlinkage
int sys_clone(unsigned long clone_flags
, unsigned long newsp
,
376 unsigned long parent_tidptr
,
377 unsigned long child_tidptr
,
378 struct pt_regs __regs
)
380 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
382 newsp
= regs
->regs
[15];
383 return do_fork(clone_flags
, newsp
, regs
, 0,
384 (int __user
*)parent_tidptr
,
385 (int __user
*)child_tidptr
);
389 * This is trivial, and on the face of it looks like it
390 * could equally well be done in user mode.
392 * Not so, for quite unobvious reasons - register pressure.
393 * In user mode vfork() cannot have a stack frame, and if
394 * done by calling the "clone()" system call directly, you
395 * do not have enough call-clobbered registers to hold all
396 * the information you need.
398 asmlinkage
int sys_vfork(unsigned long r4
, unsigned long r5
,
399 unsigned long r6
, unsigned long r7
,
400 struct pt_regs __regs
)
402 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
403 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->regs
[15], regs
,
408 * sys_execve() executes a new program.
410 asmlinkage
int sys_execve(char __user
*ufilename
, char __user
* __user
*uargv
,
411 char __user
* __user
*uenvp
, unsigned long r7
,
412 struct pt_regs __regs
)
414 struct pt_regs
*regs
= RELOC_HIDE(&__regs
, 0);
418 filename
= getname(ufilename
);
419 error
= PTR_ERR(filename
);
420 if (IS_ERR(filename
))
423 error
= do_execve(filename
, uargv
, uenvp
, regs
);
426 current
->ptrace
&= ~PT_DTRACE
;
427 task_unlock(current
);
434 unsigned long get_wchan(struct task_struct
*p
)
438 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
442 * The same comment as on the Alpha applies here, too ...
444 pc
= thread_saved_pc(p
);
446 #ifdef CONFIG_FRAME_POINTER
447 if (in_sched_functions(pc
)) {
448 unsigned long schedule_frame
= (unsigned long)p
->thread
.sp
;
449 return ((unsigned long *)schedule_frame
)[21];
456 asmlinkage
void break_point_trap(void)
459 #if defined(CONFIG_CPU_SH4A)
460 ctrl_outl(UBC_CBR_INIT
, UBC_CBR0
);
461 ctrl_outl(UBC_CRR_INIT
, UBC_CRR0
);
463 ctrl_outw(0, UBC_BBRA
);
464 ctrl_outw(0, UBC_BBRB
);
466 current
->thread
.ubc_pc
= 0;
469 force_sig(SIGTRAP
, current
);