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-rw-r--r--arch/mips/sgi-ip30/ip30-smp.c149
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 000000000..4bfe65460
--- /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,
+};