xref: /linux/arch/x86/xen/smp_hvm.c (revision 4f77c3462308c62ffe7129cc18b9ac937f44b5a5)
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 
9 static void __init xen_hvm_smp_prepare_boot_cpu(void)
10 {
11 	BUG_ON(smp_processor_id() != 0);
12 	native_smp_prepare_boot_cpu();
13 
14 	/*
15 	 * Setup vcpu_info for boot CPU. Secondary CPUs get their vcpu_info
16 	 * in xen_cpu_up_prepare_hvm().
17 	 */
18 	xen_vcpu_setup(0);
19 
20 	/*
21 	 * Called again in case the kernel boots on vcpu >= MAX_VIRT_CPUS.
22 	 * Refer to comments in xen_hvm_init_time_ops().
23 	 */
24 	xen_hvm_init_time_ops();
25 
26 	/*
27 	 * The alternative logic (which patches the unlock/lock) runs before
28 	 * the smp bootup up code is activated. Hence we need to set this up
29 	 * the core kernel is being patched. Otherwise we will have only
30 	 * modules patched but not core code.
31 	 */
32 	xen_init_spinlocks();
33 }
34 
35 static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
36 {
37 	int cpu;
38 
39 	native_smp_prepare_cpus(max_cpus);
40 
41 	if (xen_have_vector_callback) {
42 		WARN_ON(xen_smp_intr_init(0));
43 		xen_init_lock_cpu(0);
44 	}
45 
46 	for_each_possible_cpu(cpu) {
47 		if (cpu == 0)
48 			continue;
49 
50 		/* Set default vcpu_id to make sure that we don't use cpu-0's */
51 		per_cpu(xen_vcpu_id, cpu) = XEN_VCPU_ID_INVALID;
52 	}
53 }
54 
55 #ifdef CONFIG_HOTPLUG_CPU
56 static void xen_hvm_cleanup_dead_cpu(unsigned int cpu)
57 {
58 	if (xen_have_vector_callback) {
59 		xen_smp_intr_free(cpu);
60 		xen_uninit_lock_cpu(cpu);
61 		xen_teardown_timer(cpu);
62 	}
63 }
64 #else
65 static void xen_hvm_cleanup_dead_cpu(unsigned int cpu)
66 {
67 	BUG();
68 }
69 #endif
70 
71 void __init xen_hvm_smp_init(void)
72 {
73 	smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
74 	smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
75 	smp_ops.smp_cpus_done = xen_smp_cpus_done;
76 	smp_ops.cleanup_dead_cpu = xen_hvm_cleanup_dead_cpu;
77 
78 	if (!xen_have_vector_callback) {
79 #ifdef CONFIG_PARAVIRT_SPINLOCKS
80 		nopvspin = true;
81 #endif
82 		return;
83 	}
84 
85 	smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
86 	smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
87 	smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
88 }
89