2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
15 #include <linux/sched.h>
16 #include <linux/preempt.h>
17 #include <linux/module.h>
19 #include <linux/kprobes.h>
20 #include <linux/elfcore.h>
21 #include <linux/tick.h>
22 #include <linux/init.h>
24 #include <linux/compat.h>
25 #include <linux/hardirq.h>
26 #include <linux/syscalls.h>
27 #include <linux/kernel.h>
28 #include <linux/tracehook.h>
29 #include <linux/signal.h>
30 #include <asm/stack.h>
31 #include <asm/homecache.h>
32 #include <asm/syscalls.h>
33 #include <asm/traps.h>
34 #include <asm/setup.h>
35 #ifdef CONFIG_HARDWALL
36 #include <asm/hardwall.h>
38 #include <arch/chip.h>
40 #include <arch/sim_def.h>
44 * Use the (x86) "idle=poll" option to prefer low latency when leaving the
45 * idle loop over low power while in the idle loop, e.g. if we have
46 * one thread per core and we want to get threads out of futex waits fast.
48 static int no_idle_nap
;
49 static int __init
idle_setup(char *str
)
54 if (!strcmp(str
, "poll")) {
55 pr_info("using polling idle threads.\n");
57 } else if (!strcmp(str
, "halt"))
64 early_param("idle", idle_setup
);
67 * The idle thread. There's no useful work to be
68 * done, so just try to conserve power and have a
69 * low exit latency (ie sit in a loop waiting for
70 * somebody to say that they'd like to reschedule)
74 int cpu
= smp_processor_id();
77 current_thread_info()->status
|= TS_POLLING
;
81 while (!need_resched())
87 /* endless idle loop with no priority at all */
89 tick_nohz_idle_enter();
91 while (!need_resched()) {
92 if (cpu_is_offline(cpu
))
93 BUG(); /* no HOTPLUG_CPU */
96 __get_cpu_var(irq_stat
).idle_timestamp
= jiffies
;
97 current_thread_info()->status
&= ~TS_POLLING
;
99 * TS_POLLING-cleared state must be visible before we
108 current_thread_info()->status
|= TS_POLLING
;
111 tick_nohz_idle_exit();
112 schedule_preempt_disabled();
116 struct thread_info
*alloc_thread_info_node(struct task_struct
*task
, int node
)
119 gfp_t flags
= GFP_KERNEL
;
121 #ifdef CONFIG_DEBUG_STACK_USAGE
125 page
= alloc_pages_node(node
, flags
, THREAD_SIZE_ORDER
);
129 return (struct thread_info
*)page_address(page
);
133 * Free a thread_info node, and all of its derivative
136 void free_thread_info(struct thread_info
*info
)
138 struct single_step_state
*step_state
= info
->step_state
;
140 #ifdef CONFIG_HARDWALL
142 * We free a thread_info from the context of the task that has
143 * been scheduled next, so the original task is already dead.
144 * Calling deactivate here just frees up the data structures.
145 * If the task we're freeing held the last reference to a
146 * hardwall fd, it would have been released prior to this point
147 * anyway via exit_files(), and "hardwall" would be NULL by now.
149 if (info
->task
->thread
.hardwall
)
150 hardwall_deactivate(info
->task
);
156 * FIXME: we don't munmap step_state->buffer
157 * because the mm_struct for this process (info->task->mm)
158 * has already been zeroed in exit_mm(). Keeping a
159 * reference to it here seems like a bad move, so this
160 * means we can't munmap() the buffer, and therefore if we
161 * ptrace multiple threads in a process, we will slowly
162 * leak user memory. (Note that as soon as the last
163 * thread in a process dies, we will reclaim all user
164 * memory including single-step buffers in the usual way.)
165 * We should either assign a kernel VA to this buffer
166 * somehow, or we should associate the buffer(s) with the
167 * mm itself so we can clean them up that way.
172 free_pages((unsigned long)info
, THREAD_SIZE_ORDER
);
175 static void save_arch_state(struct thread_struct
*t
);
177 int copy_thread(unsigned long clone_flags
, unsigned long sp
,
178 unsigned long stack_size
,
179 struct task_struct
*p
, struct pt_regs
*regs
)
181 struct pt_regs
*childregs
;
185 * When creating a new kernel thread we pass sp as zero.
186 * Assign it to a reasonable value now that we have the stack.
188 if (sp
== 0 && regs
->ex1
== PL_ICS_EX1(KERNEL_PL
, 0))
192 * Do not clone step state from the parent; each thread
193 * must make its own lazily.
195 task_thread_info(p
)->step_state
= NULL
;
198 * Start new thread in ret_from_fork so it schedules properly
199 * and then return from interrupt like the parent.
201 p
->thread
.pc
= (unsigned long) ret_from_fork
;
203 /* Save user stack top pointer so we can ID the stack vm area later. */
206 /* Record the pid of the process that created this one. */
207 p
->thread
.creator_pid
= current
->pid
;
210 * Copy the registers onto the kernel stack so the
211 * return-from-interrupt code will reload it into registers.
213 childregs
= task_pt_regs(p
);
215 childregs
->regs
[0] = 0; /* return value is zero */
216 childregs
->sp
= sp
; /* override with new user stack pointer */
219 * If CLONE_SETTLS is set, set "tp" in the new task to "r4",
220 * which is passed in as arg #5 to sys_clone().
222 if (clone_flags
& CLONE_SETTLS
)
223 childregs
->tp
= regs
->regs
[4];
226 * Copy the callee-saved registers from the passed pt_regs struct
227 * into the context-switch callee-saved registers area.
228 * This way when we start the interrupt-return sequence, the
229 * callee-save registers will be correctly in registers, which
230 * is how we assume the compiler leaves them as we start doing
231 * the normal return-from-interrupt path after calling C code.
232 * Zero out the C ABI save area to mark the top of the stack.
234 ksp
= (unsigned long) childregs
;
235 ksp
-= C_ABI_SAVE_AREA_SIZE
; /* interrupt-entry save area */
236 ((long *)ksp
)[0] = ((long *)ksp
)[1] = 0;
237 ksp
-= CALLEE_SAVED_REGS_COUNT
* sizeof(unsigned long);
238 memcpy((void *)ksp
, ®s
->regs
[CALLEE_SAVED_FIRST_REG
],
239 CALLEE_SAVED_REGS_COUNT
* sizeof(unsigned long));
240 ksp
-= C_ABI_SAVE_AREA_SIZE
; /* __switch_to() save area */
241 ((long *)ksp
)[0] = ((long *)ksp
)[1] = 0;
244 #if CHIP_HAS_TILE_DMA()
246 * No DMA in the new thread. We model this on the fact that
247 * fork() clears the pending signals, alarms, and aio for the child.
249 memset(&p
->thread
.tile_dma_state
, 0, sizeof(struct tile_dma_state
));
250 memset(&p
->thread
.dma_async_tlb
, 0, sizeof(struct async_tlb
));
253 #if CHIP_HAS_SN_PROC()
254 /* Likewise, the new thread is not running static processor code. */
255 p
->thread
.sn_proc_running
= 0;
256 memset(&p
->thread
.sn_async_tlb
, 0, sizeof(struct async_tlb
));
259 #if CHIP_HAS_PROC_STATUS_SPR()
260 /* New thread has its miscellaneous processor state bits clear. */
261 p
->thread
.proc_status
= 0;
264 #ifdef CONFIG_HARDWALL
265 /* New thread does not own any networks. */
266 p
->thread
.hardwall
= NULL
;
271 * Start the new thread with the current architecture state
272 * (user interrupt masks, etc.).
274 save_arch_state(&p
->thread
);
280 * Return "current" if it looks plausible, or else a pointer to a dummy.
281 * This can be helpful if we are just trying to emit a clean panic.
283 struct task_struct
*validate_current(void)
285 static struct task_struct corrupt
= { .comm
= "<corrupt>" };
286 struct task_struct
*tsk
= current
;
287 if (unlikely((unsigned long)tsk
< PAGE_OFFSET
||
288 (void *)tsk
> high_memory
||
289 ((unsigned long)tsk
& (__alignof__(*tsk
) - 1)) != 0)) {
290 pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk
, stack_pointer
);
296 /* Take and return the pointer to the previous task, for schedule_tail(). */
297 struct task_struct
*sim_notify_fork(struct task_struct
*prev
)
299 struct task_struct
*tsk
= current
;
300 __insn_mtspr(SPR_SIM_CONTROL
, SIM_CONTROL_OS_FORK_PARENT
|
301 (tsk
->thread
.creator_pid
<< _SIM_CONTROL_OPERATOR_BITS
));
302 __insn_mtspr(SPR_SIM_CONTROL
, SIM_CONTROL_OS_FORK
|
303 (tsk
->pid
<< _SIM_CONTROL_OPERATOR_BITS
));
307 int dump_task_regs(struct task_struct
*tsk
, elf_gregset_t
*regs
)
309 struct pt_regs
*ptregs
= task_pt_regs(tsk
);
310 elf_core_copy_regs(regs
, ptregs
);
314 #if CHIP_HAS_TILE_DMA()
316 /* Allow user processes to access the DMA SPRs */
317 void grant_dma_mpls(void)
319 #if CONFIG_KERNEL_PL == 2
320 __insn_mtspr(SPR_MPL_DMA_CPL_SET_1
, 1);
321 __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1
, 1);
323 __insn_mtspr(SPR_MPL_DMA_CPL_SET_0
, 1);
324 __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0
, 1);
328 /* Forbid user processes from accessing the DMA SPRs */
329 void restrict_dma_mpls(void)
331 #if CONFIG_KERNEL_PL == 2
332 __insn_mtspr(SPR_MPL_DMA_CPL_SET_2
, 1);
333 __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_2
, 1);
335 __insn_mtspr(SPR_MPL_DMA_CPL_SET_1
, 1);
336 __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1
, 1);
340 /* Pause the DMA engine, then save off its state registers. */
341 static void save_tile_dma_state(struct tile_dma_state
*dma
)
343 unsigned long state
= __insn_mfspr(SPR_DMA_USER_STATUS
);
344 unsigned long post_suspend_state
;
346 /* If we're running, suspend the engine. */
347 if ((state
& DMA_STATUS_MASK
) == SPR_DMA_STATUS__RUNNING_MASK
)
348 __insn_mtspr(SPR_DMA_CTR
, SPR_DMA_CTR__SUSPEND_MASK
);
351 * Wait for the engine to idle, then save regs. Note that we
352 * want to record the "running" bit from before suspension,
353 * and the "done" bit from after, so that we can properly
354 * distinguish a case where the user suspended the engine from
355 * the case where the kernel suspended as part of the context
359 post_suspend_state
= __insn_mfspr(SPR_DMA_USER_STATUS
);
360 } while (post_suspend_state
& SPR_DMA_STATUS__BUSY_MASK
);
362 dma
->src
= __insn_mfspr(SPR_DMA_SRC_ADDR
);
363 dma
->src_chunk
= __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR
);
364 dma
->dest
= __insn_mfspr(SPR_DMA_DST_ADDR
);
365 dma
->dest_chunk
= __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR
);
366 dma
->strides
= __insn_mfspr(SPR_DMA_STRIDE
);
367 dma
->chunk_size
= __insn_mfspr(SPR_DMA_CHUNK_SIZE
);
368 dma
->byte
= __insn_mfspr(SPR_DMA_BYTE
);
369 dma
->status
= (state
& SPR_DMA_STATUS__RUNNING_MASK
) |
370 (post_suspend_state
& SPR_DMA_STATUS__DONE_MASK
);
373 /* Restart a DMA that was running before we were context-switched out. */
374 static void restore_tile_dma_state(struct thread_struct
*t
)
376 const struct tile_dma_state
*dma
= &t
->tile_dma_state
;
379 * The only way to restore the done bit is to run a zero
380 * length transaction.
382 if ((dma
->status
& SPR_DMA_STATUS__DONE_MASK
) &&
383 !(__insn_mfspr(SPR_DMA_USER_STATUS
) & SPR_DMA_STATUS__DONE_MASK
)) {
384 __insn_mtspr(SPR_DMA_BYTE
, 0);
385 __insn_mtspr(SPR_DMA_CTR
, SPR_DMA_CTR__REQUEST_MASK
);
386 while (__insn_mfspr(SPR_DMA_USER_STATUS
) &
387 SPR_DMA_STATUS__BUSY_MASK
)
391 __insn_mtspr(SPR_DMA_SRC_ADDR
, dma
->src
);
392 __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR
, dma
->src_chunk
);
393 __insn_mtspr(SPR_DMA_DST_ADDR
, dma
->dest
);
394 __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR
, dma
->dest_chunk
);
395 __insn_mtspr(SPR_DMA_STRIDE
, dma
->strides
);
396 __insn_mtspr(SPR_DMA_CHUNK_SIZE
, dma
->chunk_size
);
397 __insn_mtspr(SPR_DMA_BYTE
, dma
->byte
);
400 * Restart the engine if we were running and not done.
401 * Clear a pending async DMA fault that we were waiting on return
402 * to user space to execute, since we expect the DMA engine
403 * to regenerate those faults for us now. Note that we don't
404 * try to clear the TIF_ASYNC_TLB flag, since it's relatively
405 * harmless if set, and it covers both DMA and the SN processor.
407 if ((dma
->status
& DMA_STATUS_MASK
) == SPR_DMA_STATUS__RUNNING_MASK
) {
408 t
->dma_async_tlb
.fault_num
= 0;
409 __insn_mtspr(SPR_DMA_CTR
, SPR_DMA_CTR__REQUEST_MASK
);
415 static void save_arch_state(struct thread_struct
*t
)
417 #if CHIP_HAS_SPLIT_INTR_MASK()
418 t
->interrupt_mask
= __insn_mfspr(SPR_INTERRUPT_MASK_0_0
) |
419 ((u64
)__insn_mfspr(SPR_INTERRUPT_MASK_0_1
) << 32);
421 t
->interrupt_mask
= __insn_mfspr(SPR_INTERRUPT_MASK_0
);
423 t
->ex_context
[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0
);
424 t
->ex_context
[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1
);
425 t
->system_save
[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0
);
426 t
->system_save
[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1
);
427 t
->system_save
[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2
);
428 t
->system_save
[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3
);
429 t
->intctrl_0
= __insn_mfspr(SPR_INTCTRL_0_STATUS
);
430 #if CHIP_HAS_PROC_STATUS_SPR()
431 t
->proc_status
= __insn_mfspr(SPR_PROC_STATUS
);
433 #if !CHIP_HAS_FIXED_INTVEC_BASE()
434 t
->interrupt_vector_base
= __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0
);
436 #if CHIP_HAS_TILE_RTF_HWM()
437 t
->tile_rtf_hwm
= __insn_mfspr(SPR_TILE_RTF_HWM
);
439 #if CHIP_HAS_DSTREAM_PF()
440 t
->dstream_pf
= __insn_mfspr(SPR_DSTREAM_PF
);
444 static void restore_arch_state(const struct thread_struct
*t
)
446 #if CHIP_HAS_SPLIT_INTR_MASK()
447 __insn_mtspr(SPR_INTERRUPT_MASK_0_0
, (u32
) t
->interrupt_mask
);
448 __insn_mtspr(SPR_INTERRUPT_MASK_0_1
, t
->interrupt_mask
>> 32);
450 __insn_mtspr(SPR_INTERRUPT_MASK_0
, t
->interrupt_mask
);
452 __insn_mtspr(SPR_EX_CONTEXT_0_0
, t
->ex_context
[0]);
453 __insn_mtspr(SPR_EX_CONTEXT_0_1
, t
->ex_context
[1]);
454 __insn_mtspr(SPR_SYSTEM_SAVE_0_0
, t
->system_save
[0]);
455 __insn_mtspr(SPR_SYSTEM_SAVE_0_1
, t
->system_save
[1]);
456 __insn_mtspr(SPR_SYSTEM_SAVE_0_2
, t
->system_save
[2]);
457 __insn_mtspr(SPR_SYSTEM_SAVE_0_3
, t
->system_save
[3]);
458 __insn_mtspr(SPR_INTCTRL_0_STATUS
, t
->intctrl_0
);
459 #if CHIP_HAS_PROC_STATUS_SPR()
460 __insn_mtspr(SPR_PROC_STATUS
, t
->proc_status
);
462 #if !CHIP_HAS_FIXED_INTVEC_BASE()
463 __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0
, t
->interrupt_vector_base
);
465 #if CHIP_HAS_TILE_RTF_HWM()
466 __insn_mtspr(SPR_TILE_RTF_HWM
, t
->tile_rtf_hwm
);
468 #if CHIP_HAS_DSTREAM_PF()
469 __insn_mtspr(SPR_DSTREAM_PF
, t
->dstream_pf
);
474 void _prepare_arch_switch(struct task_struct
*next
)
476 #if CHIP_HAS_SN_PROC()
479 #if CHIP_HAS_TILE_DMA()
480 struct tile_dma_state
*dma
= ¤t
->thread
.tile_dma_state
;
482 save_tile_dma_state(dma
);
484 #if CHIP_HAS_SN_PROC()
486 * Suspend the static network processor if it was running.
487 * We do not suspend the fabric itself, just like we don't
488 * try to suspend the UDN.
490 snctl
= __insn_mfspr(SPR_SNCTL
);
491 current
->thread
.sn_proc_running
=
492 (snctl
& SPR_SNCTL__FRZPROC_MASK
) == 0;
493 if (current
->thread
.sn_proc_running
)
494 __insn_mtspr(SPR_SNCTL
, snctl
| SPR_SNCTL__FRZPROC_MASK
);
499 struct task_struct
*__sched
_switch_to(struct task_struct
*prev
,
500 struct task_struct
*next
)
502 /* DMA state is already saved; save off other arch state. */
503 save_arch_state(&prev
->thread
);
505 #if CHIP_HAS_TILE_DMA()
507 * Restore DMA in new task if desired.
508 * Note that it is only safe to restart here since interrupts
509 * are disabled, so we can't take any DMATLB miss or access
510 * interrupts before we have finished switching stacks.
512 if (next
->thread
.tile_dma_state
.enabled
) {
513 restore_tile_dma_state(&next
->thread
);
520 /* Restore other arch state. */
521 restore_arch_state(&next
->thread
);
523 #if CHIP_HAS_SN_PROC()
525 * Restart static network processor in the new process
526 * if it was running before.
528 if (next
->thread
.sn_proc_running
) {
529 int snctl
= __insn_mfspr(SPR_SNCTL
);
530 __insn_mtspr(SPR_SNCTL
, snctl
& ~SPR_SNCTL__FRZPROC_MASK
);
534 #ifdef CONFIG_HARDWALL
535 /* Enable or disable access to the network registers appropriately. */
536 if (prev
->thread
.hardwall
!= NULL
) {
537 if (next
->thread
.hardwall
== NULL
)
538 restrict_network_mpls();
539 } else if (next
->thread
.hardwall
!= NULL
) {
540 grant_network_mpls();
545 * Switch kernel SP, PC, and callee-saved registers.
546 * In the context of the new task, return the old task pointer
547 * (i.e. the task that actually called __switch_to).
548 * Pass the value to use for SYSTEM_SAVE_K_0 when we reset our sp.
550 return __switch_to(prev
, next
, next_current_ksp0(next
));
554 * This routine is called on return from interrupt if any of the
555 * TIF_WORK_MASK flags are set in thread_info->flags. It is
556 * entered with interrupts disabled so we don't miss an event
557 * that modified the thread_info flags. If any flag is set, we
558 * handle it and return, and the calling assembly code will
559 * re-disable interrupts, reload the thread flags, and call back
560 * if more flags need to be handled.
562 * We return whether we need to check the thread_info flags again
563 * or not. Note that we don't clear TIF_SINGLESTEP here, so it's
564 * important that it be tested last, and then claim that we don't
565 * need to recheck the flags.
567 int do_work_pending(struct pt_regs
*regs
, u32 thread_info_flags
)
569 if (thread_info_flags
& _TIF_NEED_RESCHED
) {
573 #if CHIP_HAS_TILE_DMA() || CHIP_HAS_SN_PROC()
574 if (thread_info_flags
& _TIF_ASYNC_TLB
) {
575 do_async_page_fault(regs
);
579 if (thread_info_flags
& _TIF_SIGPENDING
) {
583 if (thread_info_flags
& _TIF_NOTIFY_RESUME
) {
584 clear_thread_flag(TIF_NOTIFY_RESUME
);
585 tracehook_notify_resume(regs
);
586 if (current
->replacement_session_keyring
)
587 key_replace_session_keyring();
590 if (thread_info_flags
& _TIF_SINGLESTEP
) {
591 if ((regs
->ex1
& SPR_EX_CONTEXT_1_1__PL_MASK
) == 0)
592 single_step_once(regs
);
595 panic("work_pending: bad flags %#x\n", thread_info_flags
);
598 /* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */
599 SYSCALL_DEFINE5(clone
, unsigned long, clone_flags
, unsigned long, newsp
,
600 void __user
*, parent_tidptr
, void __user
*, child_tidptr
,
601 struct pt_regs
*, regs
)
605 return do_fork(clone_flags
, newsp
, regs
, 0,
606 parent_tidptr
, child_tidptr
);
610 * sys_execve() executes a new program.
612 SYSCALL_DEFINE4(execve
, const char __user
*, path
,
613 const char __user
*const __user
*, argv
,
614 const char __user
*const __user
*, envp
,
615 struct pt_regs
*, regs
)
620 filename
= getname(path
);
621 error
= PTR_ERR(filename
);
622 if (IS_ERR(filename
))
624 error
= do_execve(filename
, argv
, envp
, regs
);
627 single_step_execve();
633 long compat_sys_execve(const char __user
*path
,
634 compat_uptr_t __user
*argv
,
635 compat_uptr_t __user
*envp
,
636 struct pt_regs
*regs
)
641 filename
= getname(path
);
642 error
= PTR_ERR(filename
);
643 if (IS_ERR(filename
))
645 error
= compat_do_execve(filename
, argv
, envp
, regs
);
648 single_step_execve();
654 unsigned long get_wchan(struct task_struct
*p
)
656 struct KBacktraceIterator kbt
;
658 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
661 for (KBacktraceIterator_init(&kbt
, p
, NULL
);
662 !KBacktraceIterator_end(&kbt
);
663 KBacktraceIterator_next(&kbt
)) {
664 if (!in_sched_functions(kbt
.it
.pc
))
672 * We pass in lr as zero (cleared in kernel_thread) and the caller
673 * part of the backtrace ABI on the stack also zeroed (in copy_thread)
674 * so that backtraces will stop with this function.
675 * Note that we don't use r0, since copy_thread() clears it.
677 static void start_kernel_thread(int dummy
, int (*fn
)(int), int arg
)
683 * Create a kernel thread
685 int kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
689 memset(®s
, 0, sizeof(regs
));
690 regs
.ex1
= PL_ICS_EX1(KERNEL_PL
, 0); /* run at kernel PL, no ICS */
691 regs
.pc
= (long) start_kernel_thread
;
692 regs
.flags
= PT_FLAGS_CALLER_SAVES
; /* need to restore r1 and r2 */
693 regs
.regs
[1] = (long) fn
; /* function pointer */
694 regs
.regs
[2] = (long) arg
; /* parameter register */
696 /* Ok, create the new process.. */
697 return do_fork(flags
| CLONE_VM
| CLONE_UNTRACED
, 0, ®s
,
700 EXPORT_SYMBOL(kernel_thread
);
702 /* Flush thread state. */
703 void flush_thread(void)
709 * Free current thread data structures etc..
711 void exit_thread(void)
716 void show_regs(struct pt_regs
*regs
)
718 struct task_struct
*tsk
= validate_current();
722 pr_err(" Pid: %d, comm: %20s, CPU: %d\n",
723 tsk
->pid
, tsk
->comm
, smp_processor_id());
725 for (i
= 0; i
< 51; i
+= 3)
726 pr_err(" r%-2d: "REGFMT
" r%-2d: "REGFMT
" r%-2d: "REGFMT
"\n",
727 i
, regs
->regs
[i
], i
+1, regs
->regs
[i
+1],
728 i
+2, regs
->regs
[i
+2]);
729 pr_err(" r51: "REGFMT
" r52: "REGFMT
" tp : "REGFMT
"\n",
730 regs
->regs
[51], regs
->regs
[52], regs
->tp
);
731 pr_err(" sp : "REGFMT
" lr : "REGFMT
"\n", regs
->sp
, regs
->lr
);
733 for (i
= 0; i
< 52; i
+= 4)
734 pr_err(" r%-2d: "REGFMT
" r%-2d: "REGFMT
735 " r%-2d: "REGFMT
" r%-2d: "REGFMT
"\n",
736 i
, regs
->regs
[i
], i
+1, regs
->regs
[i
+1],
737 i
+2, regs
->regs
[i
+2], i
+3, regs
->regs
[i
+3]);
738 pr_err(" r52: "REGFMT
" tp : "REGFMT
" sp : "REGFMT
" lr : "REGFMT
"\n",
739 regs
->regs
[52], regs
->tp
, regs
->sp
, regs
->lr
);
741 pr_err(" pc : "REGFMT
" ex1: %ld faultnum: %ld\n",
742 regs
->pc
, regs
->ex1
, regs
->faultnum
);
744 dump_stack_regs(regs
);