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) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2004 Thiemo Seufer
11 #include <linux/config.h>
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/ptrace.h>
20 #include <linux/slab.h>
21 #include <linux/mman.h>
22 #include <linux/personality.h>
23 #include <linux/sys.h>
24 #include <linux/user.h>
25 #include <linux/a.out.h>
26 #include <linux/init.h>
27 #include <linux/completion.h>
28 #include <linux/kallsyms.h>
31 #include <asm/bootinfo.h>
35 #include <asm/pgtable.h>
36 #include <asm/system.h>
37 #include <asm/mipsregs.h>
38 #include <asm/processor.h>
39 #include <asm/uaccess.h>
42 #include <asm/isadep.h>
44 #ifdef CONFIG_MIPS_MT_SMTC
45 #include <asm/mipsmtregs.h>
46 extern void smtc_idle_loop_hook(void);
47 #endif /* CONFIG_MIPS_MT_SMTC */
50 * The idle thread. There's no useful work to be done, so just try to conserve
51 * power and have a low exit latency (ie sit in a loop waiting for somebody to
52 * say that they'd like to reschedule)
54 ATTRIB_NORET
void cpu_idle(void)
56 /* endless idle loop with no priority at all */
58 while (!need_resched()) {
59 #ifdef CONFIG_MIPS_MT_SMTC
60 smtc_idle_loop_hook();
61 #endif /* CONFIG_MIPS_MT_SMTC */
65 preempt_enable_no_resched();
72 * Native o32 and N64 ABI without DSP ASE
74 struct mips_abi mips_abi
= {
75 .do_signal
= do_signal
,
76 #ifdef CONFIG_TRAD_SIGNALS
77 .setup_frame
= setup_frame
,
79 .setup_rt_frame
= setup_rt_frame
82 #ifdef CONFIG_MIPS32_O32
84 * o32 compatibility on 64-bit kernels, without DSP ASE
86 struct mips_abi mips_abi_32
= {
87 .do_signal
= do_signal32
,
88 .setup_frame
= setup_frame_32
,
89 .setup_rt_frame
= setup_rt_frame_32
91 #endif /* CONFIG_MIPS32_O32 */
93 #ifdef CONFIG_MIPS32_N32
95 * N32 on 64-bit kernels, without DSP ASE
97 struct mips_abi mips_abi_n32
= {
98 .do_signal
= do_signal
,
99 .setup_rt_frame
= setup_rt_frame_n32
101 #endif /* CONFIG_MIPS32_N32 */
103 asmlinkage
void ret_from_fork(void);
105 void start_thread(struct pt_regs
* regs
, unsigned long pc
, unsigned long sp
)
107 unsigned long status
;
109 /* New thread loses kernel privileges. */
110 status
= regs
->cp0_status
& ~(ST0_CU0
|ST0_CU1
|KU_MASK
);
113 status
|= (current
->thread
.mflags
& MF_32BIT_REGS
) ? 0 : ST0_FR
;
116 regs
->cp0_status
= status
;
123 current_thread_info()->addr_limit
= USER_DS
;
126 void exit_thread(void)
130 void flush_thread(void)
134 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
135 unsigned long unused
, struct task_struct
*p
, struct pt_regs
*regs
)
137 struct thread_info
*ti
= task_thread_info(p
);
138 struct pt_regs
*childregs
;
140 p
->set_child_tid
= p
->clear_child_tid
= NULL
;
142 childksp
= (unsigned long)task_stack_page(p
) + THREAD_SIZE
- 32;
154 /* set up new TSS. */
155 childregs
= (struct pt_regs
*) childksp
- 1;
157 childregs
->regs
[7] = 0; /* Clear error flag */
159 #if defined(CONFIG_BINFMT_IRIX)
160 if (current
->personality
!= PER_LINUX
) {
161 /* Under IRIX things are a little different. */
162 childregs
->regs
[3] = 1;
166 childregs
->regs
[2] = 0; /* Child gets zero as return value */
167 regs
->regs
[2] = p
->pid
;
169 if (childregs
->cp0_status
& ST0_CU0
) {
170 childregs
->regs
[28] = (unsigned long) ti
;
171 childregs
->regs
[29] = childksp
;
172 ti
->addr_limit
= KERNEL_DS
;
174 childregs
->regs
[29] = usp
;
175 ti
->addr_limit
= USER_DS
;
177 p
->thread
.reg29
= (unsigned long) childregs
;
178 p
->thread
.reg31
= (unsigned long) ret_from_fork
;
181 * New tasks lose permission to use the fpu. This accelerates context
182 * switching for most programs since they don't use the fpu.
184 p
->thread
.cp0_status
= read_c0_status() & ~(ST0_CU2
|ST0_CU1
);
185 childregs
->cp0_status
&= ~(ST0_CU2
|ST0_CU1
);
186 clear_tsk_thread_flag(p
, TIF_USEDFPU
);
188 #ifdef CONFIG_MIPS_MT_FPAFF
190 * FPU affinity support is cleaner if we track the
191 * user-visible CPU affinity from the very beginning.
192 * The generic cpus_allowed mask will already have
193 * been copied from the parent before copy_thread
196 p
->thread
.user_cpus_allowed
= p
->cpus_allowed
;
197 #endif /* CONFIG_MIPS_MT_FPAFF */
199 if (clone_flags
& CLONE_SETTLS
)
200 ti
->tp_value
= regs
->regs
[7];
205 /* Fill in the fpu structure for a core dump.. */
206 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*r
)
208 memcpy(r
, ¤t
->thread
.fpu
, sizeof(current
->thread
.fpu
));
213 void elf_dump_regs(elf_greg_t
*gp
, struct pt_regs
*regs
)
217 for (i
= 0; i
< EF_R0
; i
++)
220 for (i
= 1; i
<= 31; i
++)
221 gp
[EF_R0
+ i
] = regs
->regs
[i
];
224 gp
[EF_LO
] = regs
->lo
;
225 gp
[EF_HI
] = regs
->hi
;
226 gp
[EF_CP0_EPC
] = regs
->cp0_epc
;
227 gp
[EF_CP0_BADVADDR
] = regs
->cp0_badvaddr
;
228 gp
[EF_CP0_STATUS
] = regs
->cp0_status
;
229 gp
[EF_CP0_CAUSE
] = regs
->cp0_cause
;
235 int dump_task_regs (struct task_struct
*tsk
, elf_gregset_t
*regs
)
237 elf_dump_regs(*regs
, task_pt_regs(tsk
));
241 int dump_task_fpu (struct task_struct
*t
, elf_fpregset_t
*fpr
)
243 memcpy(fpr
, &t
->thread
.fpu
, sizeof(current
->thread
.fpu
));
249 * Create a kernel thread
251 ATTRIB_NORET
void kernel_thread_helper(void *arg
, int (*fn
)(void *))
256 long kernel_thread(int (*fn
)(void *), void *arg
, unsigned long flags
)
260 memset(®s
, 0, sizeof(regs
));
262 regs
.regs
[4] = (unsigned long) arg
;
263 regs
.regs
[5] = (unsigned long) fn
;
264 regs
.cp0_epc
= (unsigned long) kernel_thread_helper
;
265 regs
.cp0_status
= read_c0_status();
266 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
267 regs
.cp0_status
&= ~(ST0_KUP
| ST0_IEC
);
268 regs
.cp0_status
|= ST0_IEP
;
270 regs
.cp0_status
|= ST0_EXL
;
273 /* Ok, create the new process.. */
274 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0, ®s
, 0, NULL
, NULL
);
277 static struct mips_frame_info
{
279 unsigned long func_size
;
282 } *schedule_frame
, mfinfo
[64];
283 static int mfinfo_num
;
285 static int __init
get_frame_info(struct mips_frame_info
*info
)
288 void *func
= info
->func
;
289 union mips_instruction
*ip
= (union mips_instruction
*)func
;
290 info
->pc_offset
= -1;
291 info
->frame_size
= 0;
292 for (i
= 0; i
< 128; i
++, ip
++) {
293 /* if jal, jalr, jr, stop. */
294 if (ip
->j_format
.opcode
== jal_op
||
295 (ip
->r_format
.opcode
== spec_op
&&
296 (ip
->r_format
.func
== jalr_op
||
297 ip
->r_format
.func
== jr_op
)))
300 if (info
->func_size
&& i
>= info
->func_size
/ 4)
304 ip
->i_format
.opcode
== addiu_op
&&
307 ip
->i_format
.opcode
== daddiu_op
&&
309 ip
->i_format
.rs
== 29 &&
310 ip
->i_format
.rt
== 29) {
311 /* addiu/daddiu sp,sp,-imm */
312 if (info
->frame_size
)
314 info
->frame_size
= - ip
->i_format
.simmediate
;
319 ip
->i_format
.opcode
== sw_op
&&
322 ip
->i_format
.opcode
== sd_op
&&
324 ip
->i_format
.rs
== 29 &&
325 ip
->i_format
.rt
== 31) {
326 /* sw / sd $ra, offset($sp) */
327 if (info
->pc_offset
!= -1)
330 ip
->i_format
.simmediate
/ sizeof(long);
333 if (info
->pc_offset
== -1 || info
->frame_size
== 0) {
334 if (func
== schedule
)
335 printk("Can't analyze prologue code at %p\n", func
);
336 info
->pc_offset
= -1;
337 info
->frame_size
= 0;
343 static int __init
frame_info_init(void)
346 #ifdef CONFIG_KALLSYMS
348 char namebuf
[KSYM_NAME_LEN
+ 1];
349 unsigned long start
, size
, ofs
;
350 extern char __sched_text_start
[], __sched_text_end
[];
351 extern char __lock_text_start
[], __lock_text_end
[];
353 start
= (unsigned long)__sched_text_start
;
354 for (i
= 0; i
< ARRAY_SIZE(mfinfo
); i
++) {
355 if (start
== (unsigned long)schedule
)
356 schedule_frame
= &mfinfo
[i
];
357 if (!kallsyms_lookup(start
, &size
, &ofs
, &modname
, namebuf
))
359 mfinfo
[i
].func
= (void *)(start
+ ofs
);
360 mfinfo
[i
].func_size
= size
;
362 if (start
>= (unsigned long)__lock_text_end
)
364 if (start
== (unsigned long)__sched_text_end
)
365 start
= (unsigned long)__lock_text_start
;
368 mfinfo
[0].func
= schedule
;
369 schedule_frame
= &mfinfo
[0];
371 for (i
= 0; i
< ARRAY_SIZE(mfinfo
) && mfinfo
[i
].func
; i
++)
372 get_frame_info(&mfinfo
[i
]);
378 arch_initcall(frame_info_init
);
381 * Return saved PC of a blocked thread.
383 unsigned long thread_saved_pc(struct task_struct
*tsk
)
385 struct thread_struct
*t
= &tsk
->thread
;
387 /* New born processes are a special case */
388 if (t
->reg31
== (unsigned long) ret_from_fork
)
391 if (!schedule_frame
|| schedule_frame
->pc_offset
< 0)
393 return ((unsigned long *)t
->reg29
)[schedule_frame
->pc_offset
];
396 /* get_wchan - a maintenance nightmare^W^Wpain in the ass ... */
397 unsigned long get_wchan(struct task_struct
*p
)
399 unsigned long stack_page
;
401 #ifdef CONFIG_KALLSYMS
405 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
408 stack_page
= (unsigned long)task_stack_page(p
);
409 if (!stack_page
|| !mfinfo_num
)
412 pc
= thread_saved_pc(p
);
413 #ifdef CONFIG_KALLSYMS
414 if (!in_sched_functions(pc
))
417 frame
= p
->thread
.reg29
+ schedule_frame
->frame_size
;
421 if (frame
< stack_page
|| frame
> stack_page
+ THREAD_SIZE
- 32)
424 for (i
= mfinfo_num
- 1; i
>= 0; i
--) {
425 if (pc
>= (unsigned long) mfinfo
[i
].func
)
431 pc
= ((unsigned long *)frame
)[mfinfo
[i
].pc_offset
];
432 if (!mfinfo
[i
].frame_size
)
434 frame
+= mfinfo
[i
].frame_size
;
435 } while (in_sched_functions(pc
));