v4.19.13 snapshot.
diff --git a/arch/sparc/kernel/sun4d_smp.c b/arch/sparc/kernel/sun4d_smp.c
new file mode 100644
index 0000000..ff30f03
--- /dev/null
+++ b/arch/sparc/kernel/sun4d_smp.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Sparc SS1000/SC2000 SMP support.
+ *
+ * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ *
+ * Based on sun4m's smp.c, which is:
+ * 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 <asm/sbi.h>
+#include <asm/mmu.h>
+
+#include "kernel.h"
+#include "irq.h"
+
+#define IRQ_CROSS_CALL		15
+
+static volatile int smp_processors_ready;
+static int smp_highest_cpu;
+
+static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned long val)
+{
+	__asm__ __volatile__("swap [%1], %0\n\t" :
+			     "=&r" (val), "=&r" (ptr) :
+			     "0" (val), "1" (ptr));
+	return val;
+}
+
+static void smp4d_ipi_init(void);
+
+static unsigned char cpu_leds[32];
+
+static inline void show_leds(int cpuid)
+{
+	cpuid &= 0x1e;
+	__asm__ __volatile__ ("stba %0, [%1] %2" : :
+			      "r" ((cpu_leds[cpuid] << 4) | cpu_leds[cpuid+1]),
+			      "r" (ECSR_BASE(cpuid) | BB_LEDS),
+			      "i" (ASI_M_CTL));
+}
+
+void sun4d_cpu_pre_starting(void *arg)
+{
+	int cpuid = hard_smp_processor_id();
+
+	/* Show we are alive */
+	cpu_leds[cpuid] = 0x6;
+	show_leds(cpuid);
+
+	/* Enable level15 interrupt, disable level14 interrupt for now */
+	cc_set_imsk((cc_get_imsk() & ~0x8000) | 0x4000);
+}
+
+void sun4d_cpu_pre_online(void *arg)
+{
+	unsigned long flags;
+	int cpuid;
+
+	cpuid = hard_smp_processor_id();
+
+	/* Unblock the master CPU _only_ when the scheduler state
+	 * of all secondary CPUs will be up-to-date, so after
+	 * the SMP initialization the master will be just allowed
+	 * to call the scheduler code.
+	 */
+	sun4d_swap((unsigned long *)&cpu_callin_map[cpuid], 1);
+	local_ops->cache_all();
+	local_ops->tlb_all();
+
+	while ((unsigned long)current_set[cpuid] < PAGE_OFFSET)
+		barrier();
+
+	while (current_set[cpuid]->cpu != cpuid)
+		barrier();
+
+	/* Fix idle thread fields. */
+	__asm__ __volatile__("ld [%0], %%g6\n\t"
+			     : : "r" (&current_set[cpuid])
+			     : "memory" /* paranoid */);
+
+	cpu_leds[cpuid] = 0x9;
+	show_leds(cpuid);
+
+	/* Attach to the address space of init_task. */
+	mmgrab(&init_mm);
+	current->active_mm = &init_mm;
+
+	local_ops->cache_all();
+	local_ops->tlb_all();
+
+	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
+		barrier();
+
+	spin_lock_irqsave(&sun4d_imsk_lock, flags);
+	cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
+	spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
+}
+
+/*
+ *	Cycle through the processors asking the PROM to start each one.
+ */
+void __init smp4d_boot_cpus(void)
+{
+	smp4d_ipi_init();
+	if (boot_cpu_id)
+		current_set[0] = NULL;
+	local_ops->cache_all();
+}
+
+int smp4d_boot_one_cpu(int i, struct task_struct *idle)
+{
+	unsigned long *entry = &sun4d_cpu_startup;
+	int timeout;
+	int cpu_node;
+
+	cpu_find_by_instance(i, &cpu_node, NULL);
+	current_set[i] = task_thread_info(idle);
+	/*
+	 * 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);
+
+	printk(KERN_INFO "prom_startcpu returned :)\n");
+
+	/* 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 smp4d_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. */
+	smp_processors_ready = 1;
+	sun4d_distribute_irqs();
+}
+
+/* Memory structure giving interrupt handler information about IPI generated */
+struct sun4d_ipi_work {
+	int single;
+	int msk;
+	int resched;
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);
+
+/* Initialize IPIs on the SUN4D SMP machine */
+static void __init smp4d_ipi_init(void)
+{
+	int cpu;
+	struct sun4d_ipi_work *work;
+
+	printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);
+
+	for_each_possible_cpu(cpu) {
+		work = &per_cpu(sun4d_ipi_work, cpu);
+		work->single = work->msk = work->resched = 0;
+	}
+}
+
+void sun4d_ipi_interrupt(void)
+{
+	struct sun4d_ipi_work *work = this_cpu_ptr(&sun4d_ipi_work);
+
+	if (work->single) {
+		work->single = 0;
+		smp_call_function_single_interrupt();
+	}
+	if (work->msk) {
+		work->msk = 0;
+		smp_call_function_interrupt();
+	}
+	if (work->resched) {
+		work->resched = 0;
+		smp_resched_interrupt();
+	}
+}
+
+/* +-------+-------------+-----------+------------------------------------+
+ * | bcast |  devid      |   sid     |              levels mask           |
+ * +-------+-------------+-----------+------------------------------------+
+ *  31      30         23 22       15 14                                 0
+ */
+#define IGEN_MESSAGE(bcast, devid, sid, levels) \
+	(((bcast) << 31) | ((devid) << 23) | ((sid) << 15) | (levels))
+
+static void sun4d_send_ipi(int cpu, int level)
+{
+	cc_set_igen(IGEN_MESSAGE(0, cpu << 3, 6 + ((level >> 1) & 7), 1 << (level - 1)));
+}
+
+static void sun4d_ipi_single(int cpu)
+{
+	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
+
+	/* Mark work */
+	work->single = 1;
+
+	/* Generate IRQ on the CPU */
+	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
+}
+
+static void sun4d_ipi_mask_one(int cpu)
+{
+	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
+
+	/* Mark work */
+	work->msk = 1;
+
+	/* Generate IRQ on the CPU */
+	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
+}
+
+static void sun4d_ipi_resched(int cpu)
+{
+	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
+
+	/* Mark work */
+	work->resched = 1;
+
+	/* Generate IRQ on the CPU (any IRQ will cause resched) */
+	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
+}
+
+static struct smp_funcall {
+	smpfunc_t func;
+	unsigned long arg1;
+	unsigned long arg2;
+	unsigned long arg3;
+	unsigned long arg4;
+	unsigned long arg5;
+	unsigned char processors_in[NR_CPUS];  /* Set when ipi entered. */
+	unsigned char processors_out[NR_CPUS]; /* Set when ipi exited. */
+} ccall_info __attribute__((aligned(8)));
+
+static DEFINE_SPINLOCK(cross_call_lock);
+
+/* Cross calls must be serialized, at least currently. */
+static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
+			     unsigned long arg2, unsigned long arg3,
+			     unsigned long arg4)
+{
+	if (smp_processors_ready) {
+		register int high = smp_highest_cpu;
+		unsigned long flags;
+
+		spin_lock_irqsave(&cross_call_lock, flags);
+
+		{
+			/*
+			 * If you make changes here, make sure
+			 * gcc generates proper code...
+			 */
+			register smpfunc_t f asm("i0") = func;
+			register unsigned long a1 asm("i1") = arg1;
+			register unsigned long a2 asm("i2") = arg2;
+			register unsigned long a3 asm("i3") = arg3;
+			register unsigned long a4 asm("i4") = arg4;
+			register unsigned long a5 asm("i5") = 0;
+
+			__asm__ __volatile__(
+				"std %0, [%6]\n\t"
+				"std %2, [%6 + 8]\n\t"
+				"std %4, [%6 + 16]\n\t" : :
+				"r"(f), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
+				"r" (&ccall_info.func));
+		}
+
+		/* 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 <= high; i++) {
+				if (cpumask_test_cpu(i, &mask)) {
+					ccall_info.processors_in[i] = 0;
+					ccall_info.processors_out[i] = 0;
+					sun4d_send_ipi(i, IRQ_CROSS_CALL);
+				}
+			}
+		}
+
+		{
+			register int i;
+
+			i = 0;
+			do {
+				if (!cpumask_test_cpu(i, &mask))
+					continue;
+				while (!ccall_info.processors_in[i])
+					barrier();
+			} while (++i <= high);
+
+			i = 0;
+			do {
+				if (!cpumask_test_cpu(i, &mask))
+					continue;
+				while (!ccall_info.processors_out[i])
+					barrier();
+			} while (++i <= high);
+		}
+
+		spin_unlock_irqrestore(&cross_call_lock, flags);
+	}
+}
+
+/* Running cross calls. */
+void smp4d_cross_call_irq(void)
+{
+	int i = hard_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 smp4d_percpu_timer_interrupt(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs;
+	int cpu = hard_smp_processor_id();
+	struct clock_event_device *ce;
+	static int cpu_tick[NR_CPUS];
+	static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };
+
+	old_regs = set_irq_regs(regs);
+	bw_get_prof_limit(cpu);
+	bw_clear_intr_mask(0, 1);	/* INTR_TABLE[0] & 1 is Profile IRQ */
+
+	cpu_tick[cpu]++;
+	if (!(cpu_tick[cpu] & 15)) {
+		if (cpu_tick[cpu] == 0x60)
+			cpu_tick[cpu] = 0;
+		cpu_leds[cpu] = led_mask[cpu_tick[cpu] >> 4];
+		show_leds(cpu);
+	}
+
+	ce = &per_cpu(sparc32_clockevent, cpu);
+
+	irq_enter();
+	ce->event_handler(ce);
+	irq_exit();
+
+	set_irq_regs(old_regs);
+}
+
+static const struct sparc32_ipi_ops sun4d_ipi_ops = {
+	.cross_call = sun4d_cross_call,
+	.resched    = sun4d_ipi_resched,
+	.single     = sun4d_ipi_single,
+	.mask_one   = sun4d_ipi_mask_one,
+};
+
+void __init sun4d_init_smp(void)
+{
+	int i;
+
+	/* Patch ipi15 trap table */
+	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);
+
+	sparc32_ipi_ops = &sun4d_ipi_ops;
+
+	for (i = 0; i < NR_CPUS; i++) {
+		ccall_info.processors_in[i] = 1;
+		ccall_info.processors_out[i] = 1;
+	}
+}