x86/xen/smp_hvm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/thread_info.h>
   3 #include <asm/smp.h>
   4
   5 #include <xen/events.h>
   6
   7 #include "xen-ops.h"
   8 #include "smp.h"
   9
  10
  11 static void __init xen_hvm_smp_prepare_boot_cpu(void)
  12 {
  13         BUG_ON(smp_processor_id() != 0);
  14         native_smp_prepare_boot_cpu();
  15
  16         /*
  17          * Setup vcpu_info for boot CPU. Secondary CPUs get their vcpu_info
  18          * in xen_cpu_up_prepare_hvm().
  19          */
  20         xen_vcpu_setup(0);
  21
  22         /*
  23          * Called again in case the kernel boots on vcpu >= MAX_VIRT_CPUS.
  24          * Refer to comments in xen_hvm_init_time_ops().
  25          */
  26         xen_hvm_init_time_ops();
  27
  28         /*
  29          * The alternative logic (which patches the unlock/lock) runs before
  30          * the smp bootup up code is activated. Hence we need to set this up
  31          * the core kernel is being patched. Otherwise we will have only
  32          * modules patched but not core code.
  33          */
  34         xen_init_spinlocks();
  35 }
  36
  37 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
  38 {
  39         int cpu;
  40
  41         native_smp_prepare_cpus(max_cpus);
  42
  43         if (xen_have_vector_callback) {
  44                 WARN_ON(xen_smp_intr_init(0));
  45                 xen_init_lock_cpu(0);
  46         }
  47
  48         for_each_possible_cpu(cpu) {
  49                 if (cpu == 0)
  50                         continue;
  51
  52                 /* Set default vcpu_id to make sure that we don't use cpu-0's */
  53                 per_cpu(xen_vcpu_id, cpu) = XEN_VCPU_ID_INVALID;
  54         }
  55 }
  56
  57 #ifdef CONFIG_HOTPLUG_CPU
  58 static void xen_hvm_cpu_die(unsigned int cpu)
  59 {
  60         if (common_cpu_die(cpu) == 0) {
  61                 if (xen_have_vector_callback) {
  62                         xen_smp_intr_free(cpu);
  63                         xen_uninit_lock_cpu(cpu);
  64                         xen_teardown_timer(cpu);
  65                 }
  66         }
  67 }
  68 #else
  69 static void xen_hvm_cpu_die(unsigned int cpu)
  70 {
  71         BUG();
  72 }
  73 #endif
  74
  75 void __init xen_hvm_smp_init(void)
  76 {
  77         smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
  78         smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
  79         smp_ops.smp_cpus_done = xen_smp_cpus_done;
  80         smp_ops.cpu_die = xen_hvm_cpu_die;
  81
  82         if (!xen_have_vector_callback) {
  83 #ifdef CONFIG_PARAVIRT_SPINLOCKS
  84                 nopvspin = true;
  85 #endif
  86                 return;
  87         }
  88
  89         smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
  90         smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
  91         smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
  92 }