um: Remove broken SMP support

At times where UML used the TT mode to operate it had
kind of SMP support. It never got finished nor was
stable.
Let's rip out that cruft and stop confusing developers
which do tree-wide SMP cleanups.

If someone wants SMP support UML it has do be done from scratch.

Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 0 insertions, 238 deletions

diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
deleted file mode 100644
index 5c8c3ea7db7b..000000000000
--- a/arch/um/kernel/smp.c
+++ /dev/null
@@ -1,238 +0,0 @@
-/*
- * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
- */
-
-#include <linux/percpu.h>
-#include <asm/pgalloc.h>
-#include <asm/tlb.h>
-
-#ifdef CONFIG_SMP
-
-#include <linux/sched.h>
-#include <linux/module.h>
-#include <linux/threads.h>
-#include <linux/interrupt.h>
-#include <linux/err.h>
-#include <linux/hardirq.h>
-#include <asm/smp.h>
-#include <asm/processor.h>
-#include <asm/spinlock.h>
-#include <kern.h>
-#include <irq_user.h>
-#include <os.h>
-
-/* Per CPU bogomips and other parameters
- * The only piece used here is the ipi pipe, which is set before SMP is
- * started and never changed.
- */
-struct cpuinfo_um cpu_data[NR_CPUS];
-
-/* A statistic, can be a little off */
-int num_reschedules_sent = 0;
-
-/* Not changed after boot */
-struct task_struct *idle_threads[NR_CPUS];
-
-void smp_send_reschedule(int cpu)
-{
-	os_write_file(cpu_data[cpu].ipi_pipe[1], "R", 1);
-	num_reschedules_sent++;
-}
-
-void smp_send_stop(void)
-{
-	int i;
-
-	printk(KERN_INFO "Stopping all CPUs...");
-	for (i = 0; i < num_online_cpus(); i++) {
-		if (i == current_thread->cpu)
-			continue;
-		os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);
-	}
-	printk(KERN_CONT "done\n");
-}
-
-static cpumask_t smp_commenced_mask = CPU_MASK_NONE;
-static cpumask_t cpu_callin_map = CPU_MASK_NONE;
-
-static int idle_proc(void *cpup)
-{
-	int cpu = (int) cpup, err;
-
-	err = os_pipe(cpu_data[cpu].ipi_pipe, 1, 1);
-	if (err < 0)
-		panic("CPU#%d failed to create IPI pipe, err = %d", cpu, -err);
-
-	os_set_fd_async(cpu_data[cpu].ipi_pipe[0]);
-
-	wmb();
-	if (cpu_test_and_set(cpu, cpu_callin_map)) {
-		printk(KERN_ERR "huh, CPU#%d already present??\n", cpu);
-		BUG();
-	}
-
-	while (!cpu_isset(cpu, smp_commenced_mask))
-		cpu_relax();
-
-	notify_cpu_starting(cpu);
-	set_cpu_online(cpu, true);
-	default_idle();
-	return 0;
-}
-
-static struct task_struct *idle_thread(int cpu)
-{
-	struct task_struct *new_task;
-
-	current->thread.request.u.thread.proc = idle_proc;
-	current->thread.request.u.thread.arg = (void *) cpu;
-	new_task = fork_idle(cpu);
-	if (IS_ERR(new_task))
-		panic("copy_process failed in idle_thread, error = %ld",
-		      PTR_ERR(new_task));
-
-	cpu_tasks[cpu] = ((struct cpu_task)
-		          { .pid = 	new_task->thread.mode.tt.extern_pid,
-			    .task = 	new_task } );
-	idle_threads[cpu] = new_task;
-	panic("skas mode doesn't support SMP");
-	return new_task;
-}
-
-void smp_prepare_cpus(unsigned int maxcpus)
-{
-	struct task_struct *idle;
-	unsigned long waittime;
-	int err, cpu, me = smp_processor_id();
-	int i;
-
-	for (i = 0; i < ncpus; ++i)
-		set_cpu_possible(i, true);
-
-	set_cpu_online(me, true);
-	cpu_set(me, cpu_callin_map);
-
-	err = os_pipe(cpu_data[me].ipi_pipe, 1, 1);
-	if (err < 0)
-		panic("CPU#0 failed to create IPI pipe, errno = %d", -err);
-
-	os_set_fd_async(cpu_data[me].ipi_pipe[0]);
-
-	for (cpu = 1; cpu < ncpus; cpu++) {
-		printk(KERN_INFO "Booting processor %d...\n", cpu);
-
-		idle = idle_thread(cpu);
-
-		init_idle(idle, cpu);
-
-		waittime = 200000000;
-		while (waittime-- && !cpu_isset(cpu, cpu_callin_map))
-			cpu_relax();
-
-		printk(KERN_INFO "%s\n",
-		       cpu_isset(cpu, cpu_calling_map) ? "done" : "failed");
-	}
-}
-
-void smp_prepare_boot_cpu(void)
-{
-	set_cpu_online(smp_processor_id(), true);
-}
-
-int __cpu_up(unsigned int cpu, struct task_struct *tidle)
-{
-	cpu_set(cpu, smp_commenced_mask);
-	while (!cpu_online(cpu))
-		mb();
-	return 0;
-}
-
-int setup_profiling_timer(unsigned int multiplier)
-{
-	printk(KERN_INFO "setup_profiling_timer\n");
-	return 0;
-}
-
-void smp_call_function_slave(int cpu);
-
-void IPI_handler(int cpu)
-{
-	unsigned char c;
-	int fd;
-
-	fd = cpu_data[cpu].ipi_pipe[0];
-	while (os_read_file(fd, &c, 1) == 1) {
-		switch (c) {
-		case 'C':
-			smp_call_function_slave(cpu);
-			break;
-
-		case 'R':
-			scheduler_ipi();
-			break;
-
-		case 'S':
-			printk(KERN_INFO "CPU#%d stopping\n", cpu);
-			while (1)
-				pause();
-			break;
-
-		default:
-			printk(KERN_ERR "CPU#%d received unknown IPI [%c]!\n",
-			       cpu, c);
-			break;
-		}
-	}
-}
-
-int hard_smp_processor_id(void)
-{
-	return pid_to_processor_id(os_getpid());
-}
-
-static DEFINE_SPINLOCK(call_lock);
-static atomic_t scf_started;
-static atomic_t scf_finished;
-static void (*func)(void *info);
-static void *info;
-
-void smp_call_function_slave(int cpu)
-{
-	atomic_inc(&scf_started);
-	(*func)(info);
-	atomic_inc(&scf_finished);
-}
-
-int smp_call_function(void (*_func)(void *info), void *_info, int wait)
-{
-	int cpus = num_online_cpus() - 1;
-	int i;
-
-	if (!cpus)
-		return 0;
-
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON(irqs_disabled());
-
-	spin_lock_bh(&call_lock);
-	atomic_set(&scf_started, 0);
-	atomic_set(&scf_finished, 0);
-	func = _func;
-	info = _info;
-
-	for_each_online_cpu(i)
-		os_write_file(cpu_data[i].ipi_pipe[1], "C", 1);
-
-	while (atomic_read(&scf_started) != cpus)
-		barrier();
-
-	if (wait)
-		while (atomic_read(&scf_finished) != cpus)
-			barrier();
-
-	spin_unlock_bh(&call_lock);
-	return 0;
-}
-
-#endif