v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/sun4m_smp.c b/arch/sparc/kernel/sun4m_smp.c
new file mode 100644
index 0000000..228a652
--- /dev/null
+++ b/arch/sparc/kernel/sun4m_smp.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sun4m SMP support.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/profile.h>
+#include <linux/delay.h>
+#include <linux/sched/mm.h>
+#include <linux/cpu.h>
+
+#include <asm/cacheflush.h>
+#include <asm/switch_to.h>
+#include <asm/tlbflush.h>
+#include <asm/timer.h>
+#include <asm/oplib.h>
+
+#include "irq.h"
+#include "kernel.h"
+
+#define IRQ_IPI_SINGLE 12
+#define IRQ_IPI_MASK 13
+#define IRQ_IPI_RESCHED 14
+#define IRQ_CROSS_CALL 15
+
+static inline unsigned long
+swap_ulong(volatile unsigned long *ptr, unsigned long val)
+{
+ __asm__ __volatile__("swap [%1], %0\n\t" :
+ "=&r" (val), "=&r" (ptr) :
+ "0" (val), "1" (ptr));
+ return val;
+}
+
+void sun4m_cpu_pre_starting(void *arg)
+{
+}
+
+void sun4m_cpu_pre_online(void *arg)
+{
+ int cpuid = hard_smp_processor_id();
+
+ /* Allow master to continue. The master will then give us the
+ * go-ahead by setting the smp_commenced_mask and will wait without
+ * timeouts until our setup is completed fully (signified by
+ * our bit being set in the cpu_online_mask).
+ */
+ swap_ulong(&cpu_callin_map[cpuid], 1);
+
+ /* XXX: What's up with all the flushes? */
+ local_ops->cache_all();
+ local_ops->tlb_all();
+
+ /* Fix idle thread fields. */
+ __asm__ __volatile__("ld [%0], %%g6\n\t"
+ : : "r" (¤t_set[cpuid])
+ : "memory" /* paranoid */);
+
+ /* Attach to the address space of init_task. */
+ mmgrab(&init_mm);
+ current->active_mm = &init_mm;
+
+ while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
+ mb();
+}
+
+/*
+ * Cycle through the processors asking the PROM to start each one.
+ */
+void __init smp4m_boot_cpus(void)
+{
+ sun4m_unmask_profile_irq();
+ local_ops->cache_all();
+}
+
+int smp4m_boot_one_cpu(int i, struct task_struct *idle)
+{
+ unsigned long *entry = &sun4m_cpu_startup;
+ int timeout;
+ int cpu_node;
+
+ cpu_find_by_mid(i, &cpu_node);
+ current_set[i] = task_thread_info(idle);
+
+ /* See trampoline.S for details... */
+ entry += ((i - 1) * 3);
+
+ /*
+ * Initialize the contexts table
+ * Since the call to prom_startcpu() trashes the structure,
+ * we need to re-initialize it for each cpu
+ */
+ smp_penguin_ctable.which_io = 0;
+ smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
+ smp_penguin_ctable.reg_size = 0;
+
+ /* whirrr, whirrr, whirrrrrrrrr... */
+ printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
+ local_ops->cache_all();
+ prom_startcpu(cpu_node, &smp_penguin_ctable, 0, (char *)entry);
+
+ /* wheee... it's going... */
+ for (timeout = 0; timeout < 10000; timeout++) {
+ if (cpu_callin_map[i])
+ break;
+ udelay(200);
+ }
+
+ if (!(cpu_callin_map[i])) {
+ printk(KERN_ERR "Processor %d is stuck.\n", i);
+ return -ENODEV;
+ }
+
+ local_ops->cache_all();
+ return 0;
+}
+
+void __init smp4m_smp_done(void)
+{
+ int i, first;
+ int *prev;
+
+ /* setup cpu list for irq rotation */
+ first = 0;
+ prev = &first;
+ for_each_online_cpu(i) {
+ *prev = i;
+ prev = &cpu_data(i).next;
+ }
+ *prev = first;
+ local_ops->cache_all();
+
+ /* Ok, they are spinning and ready to go. */
+}
+
+static void sun4m_send_ipi(int cpu, int level)
+{
+ sbus_writel(SUN4M_SOFT_INT(level), &sun4m_irq_percpu[cpu]->set);
+}
+
+static void sun4m_ipi_resched(int cpu)
+{
+ sun4m_send_ipi(cpu, IRQ_IPI_RESCHED);
+}
+
+static void sun4m_ipi_single(int cpu)
+{
+ sun4m_send_ipi(cpu, IRQ_IPI_SINGLE);
+}
+
+static void sun4m_ipi_mask_one(int cpu)
+{
+ sun4m_send_ipi(cpu, IRQ_IPI_MASK);
+}
+
+static struct smp_funcall {
+ smpfunc_t func;
+ unsigned long arg1;
+ unsigned long arg2;
+ unsigned long arg3;
+ unsigned long arg4;
+ unsigned long arg5;
+ unsigned long processors_in[SUN4M_NCPUS]; /* Set when ipi entered. */
+ unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
+} ccall_info;
+
+static DEFINE_SPINLOCK(cross_call_lock);
+
+/* Cross calls must be serialized, at least currently. */
+static void sun4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
+ unsigned long arg2, unsigned long arg3,
+ unsigned long arg4)
+{
+ register int ncpus = SUN4M_NCPUS;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cross_call_lock, flags);
+
+ /* Init function glue. */
+ ccall_info.func = func;
+ ccall_info.arg1 = arg1;
+ ccall_info.arg2 = arg2;
+ ccall_info.arg3 = arg3;
+ ccall_info.arg4 = arg4;
+ ccall_info.arg5 = 0;
+
+ /* Init receive/complete mapping, plus fire the IPI's off. */
+ {
+ register int i;
+
+ cpumask_clear_cpu(smp_processor_id(), &mask);
+ cpumask_and(&mask, cpu_online_mask, &mask);
+ for (i = 0; i < ncpus; i++) {
+ if (cpumask_test_cpu(i, &mask)) {
+ ccall_info.processors_in[i] = 0;
+ ccall_info.processors_out[i] = 0;
+ sun4m_send_ipi(i, IRQ_CROSS_CALL);
+ } else {
+ ccall_info.processors_in[i] = 1;
+ ccall_info.processors_out[i] = 1;
+ }
+ }
+ }
+
+ {
+ register int i;
+
+ i = 0;
+ do {
+ if (!cpumask_test_cpu(i, &mask))
+ continue;
+ while (!ccall_info.processors_in[i])
+ barrier();
+ } while (++i < ncpus);
+
+ i = 0;
+ do {
+ if (!cpumask_test_cpu(i, &mask))
+ continue;
+ while (!ccall_info.processors_out[i])
+ barrier();
+ } while (++i < ncpus);
+ }
+ spin_unlock_irqrestore(&cross_call_lock, flags);
+}
+
+/* Running cross calls. */
+void smp4m_cross_call_irq(void)
+{
+ int i = smp_processor_id();
+
+ ccall_info.processors_in[i] = 1;
+ ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
+ ccall_info.arg4, ccall_info.arg5);
+ ccall_info.processors_out[i] = 1;
+}
+
+void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
+{
+ struct pt_regs *old_regs;
+ struct clock_event_device *ce;
+ int cpu = smp_processor_id();
+
+ old_regs = set_irq_regs(regs);
+
+ ce = &per_cpu(sparc32_clockevent, cpu);
+
+ if (clockevent_state_periodic(ce))
+ sun4m_clear_profile_irq(cpu);
+ else
+ sparc_config.load_profile_irq(cpu, 0); /* Is this needless? */
+
+ irq_enter();
+ ce->event_handler(ce);
+ irq_exit();
+
+ set_irq_regs(old_regs);
+}
+
+static const struct sparc32_ipi_ops sun4m_ipi_ops = {
+ .cross_call = sun4m_cross_call,
+ .resched = sun4m_ipi_resched,
+ .single = sun4m_ipi_single,
+ .mask_one = sun4m_ipi_mask_one,
+};
+
+void __init sun4m_init_smp(void)
+{
+ sparc32_ipi_ops = &sun4m_ipi_ops;
+}