-/*
- * This is the mechanism for creating a new kernel thread.
- *
- * NOTE! Only a kernel-only process(ie the swapper or direct descendants
- * who haven't done an "execve()") should use this: it will work within
- * a system call from a "real" process, but the process memory space will
- * not be freed until both the parent and the child have exited.
- */
-pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
- long retval;
-
- /* If the parent runs before fn(arg) is called by the child,
- * the input registers of this function can be clobbered.
- * So we stash 'fn' and 'arg' into global registers which
- * will not be modified by the parent.
- */
- __asm__ __volatile__("mov %4, %%g2\n\t" /* Save FN into global */
- "mov %5, %%g3\n\t" /* Save ARG into global */
- "mov %1, %%g1\n\t" /* Clone syscall nr. */
- "mov %2, %%o0\n\t" /* Clone flags. */
- "mov 0, %%o1\n\t" /* usp arg == 0 */
- "t 0x6d\n\t" /* Linux/Sparc clone(). */
- "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
- " mov %%o0, %0\n\t"
- "jmpl %%g2, %%o7\n\t" /* Call the function. */
- " mov %%g3, %%o0\n\t" /* Set arg in delay. */
- "mov %3, %%g1\n\t"
- "t 0x6d\n\t" /* Linux/Sparc exit(). */
- /* Notreached by child. */
- "1:" :
- "=r" (retval) :
- "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
- "i" (__NR_exit), "r" (fn), "r" (arg) :
- "g1", "g2", "g3", "o0", "o1", "memory", "cc");
- return retval;
-}
-EXPORT_SYMBOL(kernel_thread);
-