xref: /openbmc/qemu/hw/acpi/cpu_hotplug.c (revision d6032e06)
1 /*
2  * QEMU ACPI hotplug utilities
3  *
4  * Copyright (C) 2013 Red Hat Inc
5  *
6  * Authors:
7  *   Igor Mammedov <imammedo@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 #include "hw/hw.h"
13 #include "hw/acpi/cpu_hotplug.h"
14 
15 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
16 {
17     AcpiCpuHotplug *cpus = opaque;
18     uint64_t val = cpus->sts[addr];
19 
20     return val;
21 }
22 
23 static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
24                              unsigned int size)
25 {
26     /* TODO: implement VCPU removal on guest signal that CPU can be removed */
27 }
28 
29 static const MemoryRegionOps AcpiCpuHotplug_ops = {
30     .read = cpu_status_read,
31     .write = cpu_status_write,
32     .endianness = DEVICE_LITTLE_ENDIAN,
33     .valid = {
34         .min_access_size = 1,
35         .max_access_size = 1,
36     },
37 };
38 
39 void AcpiCpuHotplug_add(ACPIGPE *gpe, AcpiCpuHotplug *g, CPUState *cpu)
40 {
41     CPUClass *k = CPU_GET_CLASS(cpu);
42     int64_t cpu_id;
43 
44     *gpe->sts = *gpe->sts | ACPI_CPU_HOTPLUG_STATUS;
45     cpu_id = k->get_arch_id(CPU(cpu));
46     g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
47 }
48 
49 void AcpiCpuHotplug_init(MemoryRegion *parent, Object *owner,
50                          AcpiCpuHotplug *gpe_cpu, uint16_t base)
51 {
52     CPUState *cpu;
53 
54     CPU_FOREACH(cpu) {
55         CPUClass *cc = CPU_GET_CLASS(cpu);
56         int64_t id = cc->get_arch_id(cpu);
57 
58         g_assert((id / 8) < ACPI_GPE_PROC_LEN);
59         gpe_cpu->sts[id / 8] |= (1 << (id % 8));
60     }
61     memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
62                           gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
63     memory_region_add_subregion(parent, base, &gpe_cpu->io);
64 }
65