1 files changed, 273 insertions, 0 deletions
diff --git a/arch/sparc/kernel/sun4m_smp.c b/arch/sparc/kernel/sun4m_smp.c
new file mode 100644
index 000000000..228a65270
--- /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" (&current_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;
+}