From 18280edafef1b8ffc920743eddaf6cf6612b1509 Mon Sep 17 00:00:00 2001 From: David Daney Date: Wed, 28 May 2014 23:52:13 +0200 Subject: MIPS: Add code for new system 'paravirt' For para-virtualized guests running under KVM or other equivalent hypervisor. Signed-off-by: David Daney Signed-off-by: Andreas Herrmann Cc: linux-mips@linux-mips.org Cc: James Hogan Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7004/ Signed-off-by: Ralf Baechle --- arch/mips/paravirt/paravirt-smp.c | 148 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 arch/mips/paravirt/paravirt-smp.c (limited to 'arch/mips/paravirt/paravirt-smp.c') diff --git a/arch/mips/paravirt/paravirt-smp.c b/arch/mips/paravirt/paravirt-smp.c new file mode 100644 index 000000000000..73a123e08c28 --- /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 +#include +#include +#include + +#include +#include +#include +#include + +/* + * 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, +}; -- cgit