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mips: switch to generic kernel_thread() 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-09 16:27:45 -04:00
parent ddffeb8c4d
commit 8f54bcacbc
5 changed files with 30 additions and 44 deletions
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1
arch/mips/Kconfig
View File

@ -40,6 +40,7 @@ config MIPS
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_REL
select MODULES_USE_ELF_RELA if 64BIT
select GENERIC_KERNEL_THREAD
menu "Machine selection"

2
arch/mips/include/asm/processor.h
View File

@ -310,8 +310,6 @@ struct task_struct;
/* Free all resources held by a thread. */
#define release_thread(thread) do { } while(0)
extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
extern unsigned long thread_saved_pc(struct task_struct *tsk);
/*

7
arch/mips/kernel/entry.S
View File

@ -65,6 +65,13 @@ need_resched:
b need_resched
#endif
FEXPORT(ret_from_kernel_thread)
jal schedule_tail # a0 = struct task_struct *prev
move a0, s1
jal s0
li a0, 0
j sys_exit
FEXPORT(ret_from_fork)
jal schedule_tail # a0 = struct task_struct *prev

2
arch/mips/kernel/mips_ksyms.c
View File

@ -32,8 +32,6 @@ EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memmove);
EXPORT_SYMBOL(kernel_thread);
/*
* Functions that operate on entire pages. Mostly used by memory management.
*/

62
arch/mips/kernel/process.c
View File

@ -84,6 +84,7 @@ void __noreturn cpu_idle(void)
}
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
{
@ -113,7 +114,7 @@ void flush_thread(void)
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused, struct task_struct *p, struct pt_regs *regs)
unsigned long arg, struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
@ -136,19 +137,30 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
childregs = (struct pt_regs *) childksp - 1;
/* Put the stack after the struct pt_regs. */
childksp = (unsigned long) childregs;
p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
if (unlikely(p->flags & PF_KTHREAD)) {
unsigned long status = p->thread.cp0_status;
memset(childregs, 0, sizeof(struct pt_regs));
ti->addr_limit = KERNEL_DS;
p->thread.reg16 = usp; /* fn */
p->thread.reg17 = arg;
p->thread.reg29 = childksp;
p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
((status & (ST0_KUC | ST0_IEC)) << 2);
#else
status |= ST0_EXL;
#endif
childregs->cp0_status = status;
return 0;
}
*childregs = *regs;
childregs->regs[7] = 0; /* Clear error flag */
childregs->regs[2] = 0; /* Child gets zero as return value */
childregs->regs[29] = usp;
ti->addr_limit = USER_DS;
if (childregs->cp0_status & ST0_CU0) {
childregs->regs[28] = (unsigned long) ti;
childregs->regs[29] = childksp;
ti->addr_limit = KERNEL_DS;
} else {
childregs->regs[29] = usp;
ti->addr_limit = USER_DS;
}
p->thread.reg29 = (unsigned long) childregs;
p->thread.reg31 = (unsigned long) ret_from_fork;
@ -156,7 +168,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
* New tasks lose permission to use the fpu. This accelerates context
* switching for most programs since they don't use the fpu.
*/
p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
#ifdef CONFIG_MIPS_MT_SMTC
@ -221,35 +232,6 @@ int dump_task_fpu(struct task_struct *t, elf_fpregset_t *fpr)
return 1;
}
/*
* Create a kernel thread
*/
static void __noreturn kernel_thread_helper(void *arg, int (*fn)(void *))
{
do_exit(fn(arg));
}
long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
memset(&regs, 0, sizeof(regs));
regs.regs[4] = (unsigned long) arg;
regs.regs[5] = (unsigned long) fn;
regs.cp0_epc = (unsigned long) kernel_thread_helper;
regs.cp0_status = read_c0_status();
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
regs.cp0_status = (regs.cp0_status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
((regs.cp0_status & (ST0_KUC | ST0_IEC)) << 2);
#else
regs.cp0_status |= ST0_EXL;
#endif
/* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
}
/*
*
*/