1 files changed, 149 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip30/ip30-smp.c b/arch/mips/sgi-ip30/ip30-smp.c
new file mode 100644
index 000000000000..4bfe654602b1
--- /dev/null
+++ b/arch/mips/sgi-ip30/ip30-smp.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ip30-smp.c: SMP on IP30 architecture.
+ * Based off of the original IP30 SMP code, with inspiration from ip27-smp.c
+ * and smp-bmips.c.
+ *
+ * Copyright (C) 2005-2007 Stanislaw Skowronek <skylark@unaligned.org>
+ *               2006-2007, 2014-2015 Joshua Kinard <kumba@gentoo.org>
+ *               2009 Johannes Dickgreber <tanzy@gmx.de>
+ */
+
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+
+#include <asm/time.h>
+#include <asm/sgi/heart.h>
+
+#include "ip30-common.h"
+
+#define MPCONF_MAGIC	0xbaddeed2
+#define	MPCONF_ADDR	0xa800000000000600L
+#define MPCONF_SIZE	0x80
+#define MPCONF(x)	(MPCONF_ADDR + (x) * MPCONF_SIZE)
+
+/* HEART can theoretically do 4 CPUs, but only 2 are physically possible */
+#define MP_NCPU		2
+
+struct mpconf {
+	u32 magic;
+	u32 prid;
+	u32 physid;
+	u32 virtid;
+	u32 scachesz;
+	u16 fanloads;
+	u16 res;
+	void *launch;
+	void *rendezvous;
+	u64 res2[3];
+	void *stackaddr;
+	void *lnch_parm;
+	void *rndv_parm;
+	u32 idleflag;
+};
+
+static void ip30_smp_send_ipi_single(int cpu, u32 action)
+{
+	int irq;
+
+	switch (action) {
+	case SMP_RESCHEDULE_YOURSELF:
+		irq = HEART_L2_INT_RESCHED_CPU_0;
+		break;
+	case SMP_CALL_FUNCTION:
+		irq = HEART_L2_INT_CALL_CPU_0;
+		break;
+	default:
+		panic("IP30: Unknown action value in %s!\n", __func__);
+	}
+
+	irq += cpu;
+
+	/* Poke the other CPU -- it's got mail! */
+	heart_write(BIT_ULL(irq), &heart_regs->set_isr);
+}
+
+static void ip30_smp_send_ipi_mask(const struct cpumask *mask, u32 action)
+{
+	u32 i;
+
+	for_each_cpu(i, mask)
+		ip30_smp_send_ipi_single(i, action);
+}
+
+static void __init ip30_smp_setup(void)
+{
+	int i;
+	int ncpu = 0;
+	struct mpconf *mpc;
+
+	init_cpu_possible(cpumask_of(0));
+
+	/* Scan the MPCONF structure and enumerate available CPUs. */
+	for (i = 0; i < MP_NCPU; i++) {
+		mpc = (struct mpconf *)MPCONF(i);
+		if (mpc->magic == MPCONF_MAGIC) {
+			set_cpu_possible(i, true);
+			__cpu_number_map[i] = ++ncpu;
+			__cpu_logical_map[ncpu] = i;
+			pr_info("IP30: Slot: %d, PrID: %.8x, PhyID: %d, VirtID: %d\n",
+				i, mpc->prid, mpc->physid, mpc->virtid);
+		}
+	}
+	pr_info("IP30: Detected %d CPU(s) present.\n", ncpu);
+
+	/*
+	 * Set the coherency algorithm to '5' (cacheable coherent
+	 * exclusive on write).  This is needed on IP30 SMP, especially
+	 * for R14000 CPUs, otherwise, instruction bus errors will
+	 * occur upon reaching userland.
+	 */
+	change_c0_config(CONF_CM_CMASK, CONF_CM_CACHABLE_COW);
+}
+
+static void __init ip30_smp_prepare_cpus(unsigned int max_cpus)
+{
+	/* nothing to do here */
+}
+
+static int __init ip30_smp_boot_secondary(int cpu, struct task_struct *idle)
+{
+	struct mpconf *mpc = (struct mpconf *)MPCONF(cpu);
+
+	/* Stack pointer (sp). */
+	mpc->stackaddr = (void *)__KSTK_TOS(idle);
+
+	/* Global pointer (gp). */
+	mpc->lnch_parm = task_thread_info(idle);
+
+	mb(); /* make sure stack and lparm are written */
+
+	/* Boot CPUx. */
+	mpc->launch = smp_bootstrap;
+
+	/* CPUx now executes smp_bootstrap, then ip30_smp_finish */
+	return 0;
+}
+
+static void __init ip30_smp_init_cpu(void)
+{
+	ip30_per_cpu_init();
+}
+
+static void __init ip30_smp_finish(void)
+{
+	enable_percpu_irq(get_c0_compare_int(), IRQ_TYPE_NONE);
+	local_irq_enable();
+}
+
+struct plat_smp_ops __read_mostly ip30_smp_ops = {
+	.send_ipi_single	= ip30_smp_send_ipi_single,
+	.send_ipi_mask		= ip30_smp_send_ipi_mask,
+	.smp_setup		= ip30_smp_setup,
+	.prepare_cpus		= ip30_smp_prepare_cpus,
+	.boot_secondary		= ip30_smp_boot_secondary,
+	.init_secondary		= ip30_smp_init_cpu,
+	.smp_finish		= ip30_smp_finish,
+	.prepare_boot_cpu	= ip30_smp_init_cpu,
+};