From 46f15067c020a0ce712cb2d3ef38c0589a521c15 Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Fri, 21 Sep 2012 12:26:37 -0400 Subject: c6x: add ret_from_kernel_thread(), simplify kernel_thread() Signed-off-by: Mark Salter Signed-off-by: Al Viro --- arch/c6x/kernel/entry.S | 20 ++++++++++++++++++++ arch/c6x/kernel/process.c | 38 ++++++++++++-------------------------- 2 files changed, 32 insertions(+), 26 deletions(-) diff --git a/arch/c6x/kernel/entry.S b/arch/c6x/kernel/entry.S index 30b37e5f4a6..6e6bd9d3d9c 100644 --- a/arch/c6x/kernel/entry.S +++ b/arch/c6x/kernel/entry.S @@ -400,6 +400,26 @@ ret_from_fork_2: STW .D2T2 B0,*+SP(REGS_A4+8) ENDPROC(ret_from_fork) +ENTRY(ret_from_kernel_thread) +#ifdef CONFIG_C6X_BIG_KERNEL + MVKL .S1 schedule_tail,A0 + MVKH .S1 schedule_tail,A0 + B .S2X A0 +#else + B .S2 schedule_tail +#endif + LDW .D2T2 *+SP(REGS_A0+8),B10 /* get fn */ + ADDKPC .S2 0f,B3,3 +0: + B .S2 B10 /* call fn */ + LDW .D2T1 *+SP(REGS_A1+8),A4 /* get arg */ + MVKL .S2 sys_exit,B11 + MVKH .S2 sys_exit,B11 + ADDKPC .S2 0f,B3,1 +0: + BNOP .S2 B11,5 /* jump to sys_exit */ +ENDPROC(ret_from_kernel_thread) + ;; ;; These are the interrupt handlers, responsible for calling __do_IRQ() ;; int6 is used for syscalls (see _system_call entry) diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c index 45e924a636a..d2ffc9bdaba 100644 --- a/arch/c6x/kernel/process.c +++ b/arch/c6x/kernel/process.c @@ -25,6 +25,7 @@ void (*c6x_restart)(void); void (*c6x_halt)(void); extern asmlinkage void ret_from_fork(void); +extern asmlinkage void ret_from_kernel_thread(void); /* * power off function, if any @@ -103,36 +104,21 @@ void machine_power_off(void) halt_loop(); } -static void kernel_thread_helper(int dummy, void *arg, int (*fn)(void *)) -{ - do_exit(fn(arg)); -} - /* * Create a kernel thread */ int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) { - struct pt_regs regs; - - /* - * copy_thread sets a4 to zero (child return from fork) - * so we can't just set things up to directly return to - * fn. - */ - memset(®s, 0, sizeof(regs)); - regs.b4 = (unsigned long) arg; - regs.a6 = (unsigned long) fn; - regs.pc = (unsigned long) kernel_thread_helper; - local_save_flags(regs.csr); - regs.csr |= 1; - regs.tsr = 5; /* Set GEE and GIE in TSR */ + struct pt_regs regs = { + .a0 = (unsigned long)fn, + .a1 = (unsigned long)arg, + .tsr = 0, /* kernel mode */ + }; /* Ok, create the new process.. */ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, -1, ®s, 0, NULL, NULL); } -EXPORT_SYMBOL(kernel_thread); void flush_thread(void) { @@ -192,21 +178,21 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, childregs = task_pt_regs(p); *childregs = *regs; - childregs->a4 = 0; - if (usp == -1) + if (usp == -1) { /* case of __kernel_thread: we return to supervisor space */ childregs->sp = (unsigned long)(childregs + 1); - else + p->thread.pc = (unsigned long) ret_from_kernel_thread; + } else { /* Otherwise use the given stack */ childregs->sp = usp; + p->thread.pc = (unsigned long) ret_from_fork; + } /* Set usp/ksp */ p->thread.usp = childregs->sp; - /* switch_to uses stack to save/restore 14 callee-saved regs */ thread_saved_ksp(p) = (unsigned long)childregs - 8; - p->thread.pc = (unsigned int) ret_from_fork; - p->thread.wchan = (unsigned long) ret_from_fork; + p->thread.wchan = p->thread.pc; #ifdef __DSBT__ { unsigned long dp; -- cgit v1.2.3-70-g09d2