MIPS: Add code for new system 'paravirt'
For para-virtualized guests running under KVM or other equivalent
hypervisor.
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7004/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/paravirt/paravirt-smp.c b/arch/mips/paravirt/paravirt-smp.c
new file mode 100644
index 0000000..73a123e
--- /dev/null
+++ b/arch/mips/paravirt/paravirt-smp.c
@@ -0,0 +1,148 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2013 Cavium, Inc.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/cpumask.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+
+#include <asm/mipsregs.h>
+#include <asm/setup.h>
+#include <asm/time.h>
+#include <asm/smp.h>
+
+/*
+ * Writing the sp releases the CPU, so writes must be ordered, gp
+ * first, then sp.
+ */
+unsigned long paravirt_smp_sp[NR_CPUS];
+unsigned long paravirt_smp_gp[NR_CPUS];
+
+static int numcpus = 1;
+
+static int __init set_numcpus(char *str)
+{
+ int newval;
+
+ if (get_option(&str, &newval)) {
+ if (newval < 1 || newval >= NR_CPUS)
+ goto bad;
+ numcpus = newval;
+ return 0;
+ }
+bad:
+ return -EINVAL;
+}
+early_param("numcpus", set_numcpus);
+
+
+static void paravirt_smp_setup(void)
+{
+ int id;
+ unsigned int cpunum = get_ebase_cpunum();
+
+ if (WARN_ON(cpunum >= NR_CPUS))
+ return;
+
+ /* The present CPUs are initially just the boot cpu (CPU 0). */
+ for (id = 0; id < NR_CPUS; id++) {
+ set_cpu_possible(id, id == 0);
+ set_cpu_present(id, id == 0);
+ }
+ __cpu_number_map[cpunum] = 0;
+ __cpu_logical_map[0] = cpunum;
+
+ for (id = 0; id < numcpus; id++) {
+ set_cpu_possible(id, true);
+ set_cpu_present(id, true);
+ __cpu_number_map[id] = id;
+ __cpu_logical_map[id] = id;
+ }
+}
+
+void irq_mbox_ipi(int cpu, unsigned int actions);
+static void paravirt_send_ipi_single(int cpu, unsigned int action)
+{
+ irq_mbox_ipi(cpu, action);
+}
+
+static void paravirt_send_ipi_mask(const struct cpumask *mask, unsigned int action)
+{
+ unsigned int cpu;
+
+ for_each_cpu_mask(cpu, *mask)
+ paravirt_send_ipi_single(cpu, action);
+}
+
+static void paravirt_init_secondary(void)
+{
+ unsigned int sr;
+
+ sr = set_c0_status(ST0_BEV);
+ write_c0_ebase((u32)ebase);
+
+ sr |= STATUSF_IP2; /* Interrupt controller on IP2 */
+ write_c0_status(sr);
+
+ irq_cpu_online();
+}
+
+static void paravirt_smp_finish(void)
+{
+ /* to generate the first CPU timer interrupt */
+ write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
+ local_irq_enable();
+}
+
+static void paravirt_cpus_done(void)
+{
+}
+
+static void paravirt_boot_secondary(int cpu, struct task_struct *idle)
+{
+ paravirt_smp_gp[cpu] = (unsigned long)task_thread_info(idle);
+ smp_wmb();
+ paravirt_smp_sp[cpu] = __KSTK_TOS(idle);
+}
+
+static irqreturn_t paravirt_reched_interrupt(int irq, void *dev_id)
+{
+ scheduler_ipi();
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t paravirt_function_interrupt(int irq, void *dev_id)
+{
+ smp_call_function_interrupt();
+ return IRQ_HANDLED;
+}
+
+static void paravirt_prepare_cpus(unsigned int max_cpus)
+{
+ if (request_irq(MIPS_IRQ_MBOX0, paravirt_reched_interrupt,
+ IRQF_PERCPU | IRQF_NO_THREAD, "Scheduler",
+ paravirt_reched_interrupt)) {
+ panic("Cannot request_irq for SchedulerIPI");
+ }
+ if (request_irq(MIPS_IRQ_MBOX1, paravirt_function_interrupt,
+ IRQF_PERCPU | IRQF_NO_THREAD, "SMP-Call",
+ paravirt_function_interrupt)) {
+ panic("Cannot request_irq for SMP-Call");
+ }
+}
+
+struct plat_smp_ops paravirt_smp_ops = {
+ .send_ipi_single = paravirt_send_ipi_single,
+ .send_ipi_mask = paravirt_send_ipi_mask,
+ .init_secondary = paravirt_init_secondary,
+ .smp_finish = paravirt_smp_finish,
+ .cpus_done = paravirt_cpus_done,
+ .boot_secondary = paravirt_boot_secondary,
+ .smp_setup = paravirt_smp_setup,
+ .prepare_cpus = paravirt_prepare_cpus,
+};