From 8f54bcacbc39f883bde2210cf2754e5d198f55a4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 9 Oct 2012 16:27:45 -0400 Subject: mips: switch to generic kernel_thread() Signed-off-by: Al Viro --- arch/mips/kernel/process.c | 62 ++++++++++++++++------------------------------ 1 file changed, 22 insertions(+), 40 deletions(-) (limited to 'arch/mips/kernel/process.c') diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index e9a5fd7..d13720a 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -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 @@ -222,35 +233,6 @@ int dump_task_fpu(struct task_struct *t, elf_fpregset_t *fpr) } /* - * 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(®s, 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, ®s, 0, NULL, NULL); -} - -/* * */ struct mips_frame_info { -- cgit v1.1