2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2004 Thiemo Seufer
10 #include <linux/config.h>
11 #include <linux/errno.h>
12 #include <linux/module.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
16 #include <linux/stddef.h>
17 #include <linux/unistd.h>
18 #include <linux/ptrace.h>
19 #include <linux/slab.h>
20 #include <linux/mman.h>
21 #include <linux/personality.h>
22 #include <linux/sys.h>
23 #include <linux/user.h>
24 #include <linux/a.out.h>
25 #include <linux/init.h>
26 #include <linux/completion.h>
29 #include <asm/bootinfo.h>
33 #include <asm/pgtable.h>
34 #include <asm/system.h>
35 #include <asm/mipsregs.h>
36 #include <asm/processor.h>
37 #include <asm/uaccess.h>
40 #include <asm/isadep.h>
44 * The idle thread. There's no useful work to be done, so just try to conserve
45 * power and have a low exit latency (ie sit in a loop waiting for somebody to
46 * say that they'd like to reschedule)
48 ATTRIB_NORET
void cpu_idle(void)
50 /* endless idle loop with no priority at all */
52 while (!need_resched())
59 extern int do_signal(sigset_t
*oldset
, struct pt_regs
*regs
);
60 extern int do_signal32(sigset_t
*oldset
, struct pt_regs
*regs
);
63 * Native o32 and N64 ABI without DSP ASE
65 extern void setup_frame(struct k_sigaction
* ka
, struct pt_regs
*regs
,
66 int signr
, sigset_t
*set
);
67 extern void setup_rt_frame(struct k_sigaction
* ka
, struct pt_regs
*regs
,
68 int signr
, sigset_t
*set
, siginfo_t
*info
);
70 struct mips_abi mips_abi
= {
71 .do_signal
= do_signal
,
72 #ifdef CONFIG_TRAD_SIGNALS
73 .setup_frame
= setup_frame
,
75 .setup_rt_frame
= setup_rt_frame
78 #ifdef CONFIG_MIPS32_O32
80 * o32 compatibility on 64-bit kernels, without DSP ASE
82 extern void setup_frame_32(struct k_sigaction
* ka
, struct pt_regs
*regs
,
83 int signr
, sigset_t
*set
);
84 extern void setup_rt_frame_32(struct k_sigaction
* ka
, struct pt_regs
*regs
,
85 int signr
, sigset_t
*set
, siginfo_t
*info
);
87 struct mips_abi mips_abi_32
= {
88 .do_signal
= do_signal32
,
89 .setup_frame
= setup_frame_32
,
90 .setup_rt_frame
= setup_rt_frame_32
92 #endif /* CONFIG_MIPS32_O32 */
94 #ifdef CONFIG_MIPS32_N32
96 * N32 on 64-bit kernels, without DSP ASE
98 extern void setup_rt_frame_n32(struct k_sigaction
* ka
, struct pt_regs
*regs
,
99 int signr
, sigset_t
*set
, siginfo_t
*info
);
101 struct mips_abi mips_abi_n32
= {
102 .do_signal
= do_signal
,
103 .setup_rt_frame
= setup_rt_frame_n32
105 #endif /* CONFIG_MIPS32_N32 */
107 asmlinkage
void ret_from_fork(void);
109 void start_thread(struct pt_regs
* regs
, unsigned long pc
, unsigned long sp
)
111 unsigned long status
;
113 /* New thread loses kernel privileges. */
114 status
= regs
->cp0_status
& ~(ST0_CU0
|ST0_CU1
|KU_MASK
);
117 status
|= (current
->thread
.mflags
& MF_32BIT_REGS
) ? 0 : ST0_FR
;
120 regs
->cp0_status
= status
;
127 current_thread_info()->addr_limit
= USER_DS
;
130 void exit_thread(void)
134 void flush_thread(void)
138 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
139 unsigned long unused
, struct task_struct
*p
, struct pt_regs
*regs
)
141 struct thread_info
*ti
= p
->thread_info
;
142 struct pt_regs
*childregs
;
144 p
->set_child_tid
= p
->clear_child_tid
= NULL
;
146 childksp
= (unsigned long)ti
+ THREAD_SIZE
- 32;
158 /* set up new TSS. */
159 childregs
= (struct pt_regs
*) childksp
- 1;
161 childregs
->regs
[7] = 0; /* Clear error flag */
163 #if defined(CONFIG_BINFMT_IRIX)
164 if (current
->personality
!= PER_LINUX
) {
165 /* Under IRIX things are a little different. */
166 childregs
->regs
[3] = 1;
170 childregs
->regs
[2] = 0; /* Child gets zero as return value */
171 regs
->regs
[2] = p
->pid
;
173 if (childregs
->cp0_status
& ST0_CU0
) {
174 childregs
->regs
[28] = (unsigned long) ti
;
175 childregs
->regs
[29] = childksp
;
176 ti
->addr_limit
= KERNEL_DS
;
178 childregs
->regs
[29] = usp
;
179 ti
->addr_limit
= USER_DS
;
181 p
->thread
.reg29
= (unsigned long) childregs
;
182 p
->thread
.reg31
= (unsigned long) ret_from_fork
;
185 * New tasks lose permission to use the fpu. This accelerates context
186 * switching for most programs since they don't use the fpu.
188 p
->thread
.cp0_status
= read_c0_status() & ~(ST0_CU2
|ST0_CU1
);
189 childregs
->cp0_status
&= ~(ST0_CU2
|ST0_CU1
);
190 clear_tsk_thread_flag(p
, TIF_USEDFPU
);
192 if (clone_flags
& CLONE_SETTLS
)
193 ti
->tp_value
= regs
->regs
[7];
198 /* Fill in the fpu structure for a core dump.. */
199 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*r
)
201 memcpy(r
, ¤t
->thread
.fpu
, sizeof(current
->thread
.fpu
));
206 void dump_regs(elf_greg_t
*gp
, struct pt_regs
*regs
)
210 for (i
= 0; i
< EF_R0
; i
++)
213 for (i
= 1; i
<= 31; i
++)
214 gp
[EF_R0
+ i
] = regs
->regs
[i
];
217 gp
[EF_LO
] = regs
->lo
;
218 gp
[EF_HI
] = regs
->hi
;
219 gp
[EF_CP0_EPC
] = regs
->cp0_epc
;
220 gp
[EF_CP0_BADVADDR
] = regs
->cp0_badvaddr
;
221 gp
[EF_CP0_STATUS
] = regs
->cp0_status
;
222 gp
[EF_CP0_CAUSE
] = regs
->cp0_cause
;
228 int dump_task_regs (struct task_struct
*tsk
, elf_gregset_t
*regs
)
230 struct thread_info
*ti
= tsk
->thread_info
;
231 long ksp
= (unsigned long)ti
+ THREAD_SIZE
- 32;
232 dump_regs(&(*regs
)[0], (struct pt_regs
*) ksp
- 1);
236 int dump_task_fpu (struct task_struct
*t
, elf_fpregset_t
*fpr
)
238 memcpy(fpr
, &t
->thread
.fpu
, sizeof(current
->thread
.fpu
));
244 * Create a kernel thread
246 ATTRIB_NORET
void kernel_thread_helper(void *arg
, int (*fn
)(void *))
251 long kernel_thread(int (*fn
)(void *), void *arg
, unsigned long flags
)
255 memset(®s
, 0, sizeof(regs
));
257 regs
.regs
[4] = (unsigned long) arg
;
258 regs
.regs
[5] = (unsigned long) fn
;
259 regs
.cp0_epc
= (unsigned long) kernel_thread_helper
;
260 regs
.cp0_status
= read_c0_status();
261 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
262 regs
.cp0_status
&= ~(ST0_KUP
| ST0_IEC
);
263 regs
.cp0_status
|= ST0_IEP
;
265 regs
.cp0_status
|= ST0_EXL
;
268 /* Ok, create the new process.. */
269 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0, ®s
, 0, NULL
, NULL
);
272 static struct mips_frame_info
{
274 int omit_fp
; /* compiled without fno-omit-frame-pointer */
277 } schedule_frame
, mfinfo
[] = {
278 { schedule
, 0 }, /* must be first */
279 /* arch/mips/kernel/semaphore.c */
281 { __down_interruptible
, 1 },
283 #ifdef CONFIG_PREEMPT
284 { preempt_schedule
, 0 },
286 { wait_for_completion
, 0 },
287 { interruptible_sleep_on
, 0 },
288 { interruptible_sleep_on_timeout
, 0 },
290 { sleep_on_timeout
, 0 },
293 { io_schedule_timeout
, 0 },
294 #if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
295 { __preempt_spin_lock
, 0 },
296 { __preempt_write_lock
, 0 },
299 { schedule_timeout
, 1 },
300 /* { nanosleep_restart, 1 }, */
301 /* lib/rwsem-spinlock.c */
306 static int mips_frame_info_initialized
;
307 static int __init
get_frame_info(struct mips_frame_info
*info
)
310 void *func
= info
->func
;
311 union mips_instruction
*ip
= (union mips_instruction
*)func
;
312 info
->pc_offset
= -1;
313 info
->frame_offset
= info
->omit_fp
? 0 : -1;
314 for (i
= 0; i
< 128; i
++, ip
++) {
315 /* if jal, jalr, jr, stop. */
316 if (ip
->j_format
.opcode
== jal_op
||
317 (ip
->r_format
.opcode
== spec_op
&&
318 (ip
->r_format
.func
== jalr_op
||
319 ip
->r_format
.func
== jr_op
)))
324 ip
->i_format
.opcode
== sw_op
&&
327 ip
->i_format
.opcode
== sd_op
&&
329 ip
->i_format
.rs
== 29)
331 /* sw / sd $ra, offset($sp) */
332 if (ip
->i_format
.rt
== 31) {
333 if (info
->pc_offset
!= -1)
336 ip
->i_format
.simmediate
/ sizeof(long);
338 /* sw / sd $s8, offset($sp) */
339 if (ip
->i_format
.rt
== 30) {
340 //#if 0 /* gcc 3.4 does aggressive optimization... */
341 if (info
->frame_offset
!= -1)
345 ip
->i_format
.simmediate
/ sizeof(long);
349 if (info
->pc_offset
== -1 || info
->frame_offset
== -1) {
350 printk("Can't analyze prologue code at %p\n", func
);
351 info
->pc_offset
= -1;
352 info
->frame_offset
= -1;
359 static int __init
frame_info_init(void)
362 for (i
= 0; i
< ARRAY_SIZE(mfinfo
); i
++)
363 if (get_frame_info(&mfinfo
[i
]))
365 schedule_frame
= mfinfo
[0];
368 struct mips_frame_info tmp
;
370 for (i
= 1; i
< ARRAY_SIZE(mfinfo
); i
++) {
371 if (mfinfo
[i
-1].func
> mfinfo
[i
].func
) {
373 mfinfo
[i
] = mfinfo
[i
-1];
379 mips_frame_info_initialized
= 1;
383 arch_initcall(frame_info_init
);
386 * Return saved PC of a blocked thread.
388 unsigned long thread_saved_pc(struct task_struct
*tsk
)
390 struct thread_struct
*t
= &tsk
->thread
;
392 /* New born processes are a special case */
393 if (t
->reg31
== (unsigned long) ret_from_fork
)
396 if (schedule_frame
.pc_offset
< 0)
398 return ((unsigned long *)t
->reg29
)[schedule_frame
.pc_offset
];
401 /* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */
402 unsigned long get_wchan(struct task_struct
*p
)
404 unsigned long stack_page
;
405 unsigned long frame
, pc
;
407 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
410 stack_page
= (unsigned long)p
->thread_info
;
411 if (!stack_page
|| !mips_frame_info_initialized
)
414 pc
= thread_saved_pc(p
);
415 if (!in_sched_functions(pc
))
418 frame
= ((unsigned long *)p
->thread
.reg30
)[schedule_frame
.frame_offset
];
422 if (frame
< stack_page
|| frame
> stack_page
+ THREAD_SIZE
- 32)
425 for (i
= ARRAY_SIZE(mfinfo
) - 1; i
>= 0; i
--) {
426 if (pc
>= (unsigned long) mfinfo
[i
].func
)
432 if (mfinfo
[i
].omit_fp
)
434 pc
= ((unsigned long *)frame
)[mfinfo
[i
].pc_offset
];
435 frame
= ((unsigned long *)frame
)[mfinfo
[i
].frame_offset
];
436 } while (in_sched_functions(pc
));
441 EXPORT_SYMBOL(get_wchan
);