h8300: generic kernel_thread()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

6 files changed, 21 insertions, 36 deletions

diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index 98fabd10e95f..4cef8a91c2a0 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -8,6 +8,7 @@ config H8300
         select GENERIC_IRQ_SHOW
         select GENERIC_CPU_DEVICES
         select MODULES_USE_ELF_RELA
+        select GENERIC_KERNEL_THREAD
 
 config SYMBOL_PREFIX
         string
diff --git a/arch/h8300/include/asm/processor.h b/arch/h8300/include/asm/processor.h
index 4c9f6f87b617..4b0ca49bb463 100644
--- a/arch/h8300/include/asm/processor.h
+++ b/arch/h8300/include/asm/processor.h
@@ -107,8 +107,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
-
 /*
  * Free current thread data structures etc..
  */
diff --git a/arch/h8300/include/asm/ptrace.h b/arch/h8300/include/asm/ptrace.h
index d09c440bdba7..00502a61bf0a 100644
--- a/arch/h8300/include/asm/ptrace.h
+++ b/arch/h8300/include/asm/ptrace.h
@@ -60,6 +60,8 @@ struct pt_regs {
 #define user_mode(regs) (!((regs)->ccr & PS_S))
 #define instruction_pointer(regs) ((regs)->pc)
 #define profile_pc(regs) instruction_pointer(regs)
+#define current_pt_regs() ((struct pt_regs *) \
+        (THREAD_SIZE + (unsigned long)current_thread_info()) - 1)
 #endif /* __KERNEL__ */
 #endif /* __ASSEMBLY__ */
 #endif /* _H8300_PTRACE_H */
diff --git a/arch/h8300/kernel/entry.S b/arch/h8300/kernel/entry.S
index ca7431690300..2cdb49a56099 100644
--- a/arch/h8300/kernel/entry.S
+++ b/arch/h8300/kernel/entry.S
@@ -158,6 +158,7 @@ INTERRUPTS = 128
 .globl SYMBOL_NAME(system_call)
 .globl SYMBOL_NAME(ret_from_exception)
 .globl SYMBOL_NAME(ret_from_fork)
+.globl SYMBOL_NAME(ret_from_kernel_thread)
 .globl SYMBOL_NAME(ret_from_interrupt)
 .globl SYMBOL_NAME(interrupt_redirect_table)
 .globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
@@ -330,6 +331,15 @@ SYMBOL_NAME_LABEL(ret_from_fork)
         jsr     @SYMBOL_NAME(schedule_tail)
         jmp     @SYMBOL_NAME(ret_from_exception)
 
+SYMBOL_NAME_LABEL(ret_from_kernel_thread)
+        mov.l   er2,er0
+        jsr     @SYMBOL_NAME(schedule_tail)
+        mov.l   @(LER4:16,sp),er0
+        mov.l   @(LER5:16,sp),er1
+        jsr     @er1
+        sub.l   @er0,@er0
+        jsr     @SYMBOL_NAME(sys_exit)
+
 SYMBOL_NAME_LABEL(resume)
         /*
          * Beware - when entering resume, offset of tss is in d1,
diff --git a/arch/h8300/kernel/h8300_ksyms.c b/arch/h8300/kernel/h8300_ksyms.c
index 6866bd9c7fb4..53d7c0e4bd83 100644
--- a/arch/h8300/kernel/h8300_ksyms.c
+++ b/arch/h8300/kernel/h8300_ksyms.c
@@ -33,7 +33,6 @@ EXPORT_SYMBOL(strncmp);
 
 EXPORT_SYMBOL(ip_fast_csum);
 
-EXPORT_SYMBOL(kernel_thread);
 EXPORT_SYMBOL(enable_irq);
 EXPORT_SYMBOL(disable_irq);
 
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
index e8dc1393a13a..e3dfea71c15f 100644
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -47,6 +47,7 @@ void (*pm_power_off)(void) = NULL;
 EXPORT_SYMBOL(pm_power_off);
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
 
 /*
  * The idle loop on an H8/300..
@@ -122,39 +123,6 @@ void show_regs(struct pt_regs * regs)
                 printk("\n");
 }
 
-/*
- * Create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-        long retval;
-        long clone_arg;
-        mm_segment_t fs;
-
-        fs = get_fs();
-        set_fs (KERNEL_DS);
-        clone_arg = flags | CLONE_VM;
-        __asm__("mov.l sp,er3\n\t"
-                "sub.l er2,er2\n\t"
-                "mov.l %2,er1\n\t"
-                "mov.l %1,er0\n\t"
-                "trapa #0\n\t"
-                "cmp.l sp,er3\n\t"
-                "beq 1f\n\t"
-                "mov.l %4,er0\n\t"
-                "mov.l %3,er1\n\t"
-                "jsr @er1\n\t"
-                "mov.l %5,er0\n\t"
-                "trapa #0\n"
-                "1:\n\t"
-                "mov.l er0,%0"
-                :"=r"(retval)
-                :"i"(__NR_clone),"g"(clone_arg),"g"(fn),"g"(arg),"i"(__NR_exit)
-                :"er0","er1","er2","er3");
-        set_fs (fs);
-        return retval;
-}
-
 void flush_thread(void)
 {
 }
@@ -198,6 +166,13 @@ int copy_thread(unsigned long clone_flags,
 
         childregs = (struct pt_regs *) (THREAD_SIZE + task_stack_page(p)) - 1;
 
+        if (unlikely(p->flags & PF_KTHREAD)) {
+                memset(childregs, 0, sizeof(struct pt_regs));
+                childregs->retpc = (unsigned long) ret_from_kernel_thread;
+                childregs->er4 = topstk; /* arg */
+                childregs->er5 = usp; /* fn */
+                p->thread.ksp = (unsigned long)childregs;
+        }
         *childregs = *regs;
         childregs->retpc = (unsigned long) ret_from_fork;
         childregs->er0 = 0;