LXR qemu/hw/acpi/cpu

   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 "qemu/osdep.h"
  13#include "hw/hw.h"
  14#include "hw/acpi/cpu_hotplug.h"
  15#include "qapi/error.h"
  16#include "qom/cpu.h"
  17#include "hw/i386/pc.h"
  18
  19#define CPU_EJECT_METHOD "CPEJ"
  20#define CPU_MAT_METHOD "CPMA"
  21#define CPU_ON_BITMAP "CPON"
  22#define CPU_STATUS_METHOD "CPST"
  23#define CPU_STATUS_MAP "PRS"
  24#define CPU_SCAN_METHOD "PRSC"
  25
  26static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
  27{
  28    AcpiCpuHotplug *cpus = opaque;
  29    uint64_t val = cpus->sts[addr];
  30
  31    return val;
  32}
  33
  34static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
  35                             unsigned int size)
  36{
  37    /* firmware never used to write in CPU present bitmap so use
  38       this fact as means to switch QEMU into modern CPU hotplug
  39       mode by writing 0 at the beginning of legacy CPU bitmap
  40     */
  41    if (addr == 0 && data == 0) {
  42        AcpiCpuHotplug *cpus = opaque;
  43        object_property_set_bool(cpus->device, false, "cpu-hotplug-legacy",
  44                                 &error_abort);
  45    }
  46}
  47
  48static const MemoryRegionOps AcpiCpuHotplug_ops = {
  49    .read = cpu_status_read,
  50    .write = cpu_status_write,
  51    .endianness = DEVICE_LITTLE_ENDIAN,
  52    .valid = {
  53        .min_access_size = 1,
  54        .max_access_size = 1,
  55    },
  56};
  57
  58static void acpi_set_cpu_present_bit(AcpiCpuHotplug *g, CPUState *cpu,
  59                                     Error **errp)
  60{
  61    CPUClass *k = CPU_GET_CLASS(cpu);
  62    int64_t cpu_id;
  63
  64    cpu_id = k->get_arch_id(cpu);
  65    if ((cpu_id / 8) >= ACPI_GPE_PROC_LEN) {
  66        error_setg(errp, "acpi: invalid cpu id: %" PRIi64, cpu_id);
  67        return;
  68    }
  69
  70    g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
  71}
  72
  73void legacy_acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
  74                             AcpiCpuHotplug *g, DeviceState *dev, Error **errp)
  75{
  76    acpi_set_cpu_present_bit(g, CPU(dev), errp);
  77    if (*errp != NULL) {
  78        return;
  79    }
  80    acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
  81}
  82
  83void legacy_acpi_cpu_hotplug_init(MemoryRegion *parent, Object *owner,
  84                                  AcpiCpuHotplug *gpe_cpu, uint16_t base)
  85{
  86    CPUState *cpu;
  87
  88    CPU_FOREACH(cpu) {
  89        acpi_set_cpu_present_bit(gpe_cpu, cpu, &error_abort);
  90    }
  91    memory_region_init_io(&gpe_cpu->io, owner, &AcpiCpuHotplug_ops,
  92                          gpe_cpu, "acpi-cpu-hotplug", ACPI_GPE_PROC_LEN);
  93    memory_region_add_subregion(parent, base, &gpe_cpu->io);
  94    gpe_cpu->device = owner;
  95}
  96
  97void acpi_switch_to_modern_cphp(AcpiCpuHotplug *gpe_cpu,
  98                                CPUHotplugState *cpuhp_state,
  99                                uint16_t io_port)
 100{
 101    MemoryRegion *parent = pci_address_space_io(PCI_DEVICE(gpe_cpu->device));
 102
 103    memory_region_del_subregion(parent, &gpe_cpu->io);
 104    cpu_hotplug_hw_init(parent, gpe_cpu->device, cpuhp_state, io_port);
 105}
 106
 107void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
 108                                  uint16_t io_base)
 109{
 110    Aml *dev;
 111    Aml *crs;
 112    Aml *pkg;
 113    Aml *field;
 114    Aml *method;
 115    Aml *if_ctx;
 116    Aml *else_ctx;
 117    int i, apic_idx;
 118    Aml *sb_scope = aml_scope("_SB");
 119    uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
 120    Aml *cpu_id = aml_arg(1);
 121    Aml *apic_id = aml_arg(0);
 122    Aml *cpu_on = aml_local(0);
 123    Aml *madt = aml_local(1);
 124    Aml *cpus_map = aml_name(CPU_ON_BITMAP);
 125    Aml *zero = aml_int(0);
 126    Aml *one = aml_int(1);
 127    MachineClass *mc = MACHINE_GET_CLASS(machine);
 128    CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
 129    PCMachineState *pcms = PC_MACHINE(machine);
 130
 131    /*
 132     * _MAT method - creates an madt apic buffer
 133     * apic_id = Arg0 = Local APIC ID
 134     * cpu_id  = Arg1 = Processor ID
 135     * cpu_on = Local0 = CPON flag for this cpu
 136     * madt = Local1 = Buffer (in madt apic form) to return
 137     */
 138    method = aml_method(CPU_MAT_METHOD, 2, AML_NOTSERIALIZED);
 139    aml_append(method,
 140        aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 141    aml_append(method,
 142        aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
 143    /* Update the processor id, lapic id, and enable/disable status */
 144    aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
 145    aml_append(method, aml_store(apic_id, aml_index(madt, aml_int(3))));
 146    aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
 147    aml_append(method, aml_return(madt));
 148    aml_append(sb_scope, method);
 149
 150    /*
 151     * _STA method - return ON status of cpu
 152     * apic_id = Arg0 = Local APIC ID
 153     * cpu_on = Local0 = CPON flag for this cpu
 154     */
 155    method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
 156    aml_append(method,
 157        aml_store(aml_derefof(aml_index(cpus_map, apic_id)), cpu_on));
 158    if_ctx = aml_if(cpu_on);
 159    {
 160        aml_append(if_ctx, aml_return(aml_int(0xF)));
 161    }
 162    aml_append(method, if_ctx);
 163    else_ctx = aml_else();
 164    {
 165        aml_append(else_ctx, aml_return(zero));
 166    }
 167    aml_append(method, else_ctx);
 168    aml_append(sb_scope, method);
 169
 170    method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
 171    aml_append(method, aml_sleep(200));
 172    aml_append(sb_scope, method);
 173
 174    method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
 175    {
 176        Aml *while_ctx, *if_ctx2, *else_ctx2;
 177        Aml *bus_check_evt = aml_int(1);
 178        Aml *remove_evt = aml_int(3);
 179        Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
 180        Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
 181        Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 182        Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 183        Aml *status = aml_local(3); /* Local3 = active state for cpu */
 184
 185        aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 186        aml_append(method, aml_store(zero, byte));
 187        aml_append(method, aml_store(zero, idx));
 188
 189        /* While (idx < SizeOf(CPON)) */
 190        while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 191        aml_append(while_ctx,
 192            aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 193
 194        if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 195        {
 196            /* Shift down previously read bitmap byte */
 197            aml_append(if_ctx, aml_shiftright(byte, one, byte));
 198        }
 199        aml_append(while_ctx, if_ctx);
 200
 201        else_ctx = aml_else();
 202        {
 203            /* Read next byte from cpu bitmap */
 204            aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 205                       aml_shiftright(idx, aml_int(3), NULL))), byte));
 206        }
 207        aml_append(while_ctx, else_ctx);
 208
 209        aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 210        if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 211        {
 212            /* State change - update CPON with new state */
 213            aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 214            if_ctx2 = aml_if(aml_equal(status, one));
 215            {
 216                aml_append(if_ctx2,
 217                    aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 218            }
 219            aml_append(if_ctx, if_ctx2);
 220            else_ctx2 = aml_else();
 221            {
 222                aml_append(else_ctx2,
 223                    aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 224            }
 225        }
 226        aml_append(if_ctx, else_ctx2);
 227        aml_append(while_ctx, if_ctx);
 228
 229        aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 230        aml_append(method, while_ctx);
 231    }
 232    aml_append(sb_scope, method);
 233
 234    /* The current AML generator can cover the APIC ID range [0..255],
 235     * inclusive, for VCPU hotplug. */
 236    QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 237    g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT);
 238
 239    /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 240    dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 241    aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 242    aml_append(dev,
 243        aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 244    );
 245    /* device present, functioning, decoding, not shown in UI */
 246    aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 247    crs = aml_resource_template();
 248    aml_append(crs,
 249        aml_io(AML_DECODE16, io_base, io_base, 1, ACPI_GPE_PROC_LEN)
 250    );
 251    aml_append(dev, aml_name_decl("_CRS", crs));
 252    aml_append(sb_scope, dev);
 253    /* declare CPU hotplug MMIO region and PRS field to access it */
 254    aml_append(sb_scope, aml_operation_region(
 255        "PRST", AML_SYSTEM_IO, aml_int(io_base), ACPI_GPE_PROC_LEN));
 256    field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 257    aml_append(field, aml_named_field("PRS", 256));
 258    aml_append(sb_scope, field);
 259
 260    /* build Processor object for each processor */
 261    for (i = 0; i < apic_ids->len; i++) {
 262        int apic_id = apic_ids->cpus[i].arch_id;
 263
 264        assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 265
 266        dev = aml_processor(i, 0, 0, "CP%.02X", apic_id);
 267
 268        method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 269        aml_append(method,
 270            aml_return(aml_call2(CPU_MAT_METHOD, aml_int(apic_id), aml_int(i))
 271        ));
 272        aml_append(dev, method);
 273
 274        method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 275        aml_append(method,
 276            aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
 277        aml_append(dev, method);
 278
 279        method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 280        aml_append(method,
 281            aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
 282                aml_arg(0)))
 283        );
 284        aml_append(dev, method);
 285
 286        aml_append(sb_scope, dev);
 287    }
 288
 289    /* build this code:
 290     *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 291     */
 292    /* Arg0 = APIC ID */
 293    method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 294    for (i = 0; i < apic_ids->len; i++) {
 295        int apic_id = apic_ids->cpus[i].arch_id;
 296
 297        if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
 298        aml_append(if_ctx,
 299            aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
 300        );
 301        aml_append(method, if_ctx);
 302    }
 303    aml_append(sb_scope, method);
 304
 305    /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 306     *
 307     * Note: The ability to create variable-sized packages was first
 308     * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 309     * ith up to 255 elements. Windows guests up to win2k8 fail when
 310     * VarPackageOp is used.
 311     */
 312    pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :
 313                                       aml_varpackage(pcms->apic_id_limit);
 314
 315    for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 316        int apic_id = apic_ids->cpus[i].arch_id;
 317
 318        for (; apic_idx < apic_id; apic_idx++) {
 319            aml_append(pkg, aml_int(0));
 320        }
 321        aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 322        apic_idx = apic_id + 1;
 323    }
 324    aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 325    g_free(apic_ids);
 326
 327    aml_append(ctx, sb_scope);
 328
 329    method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 330    aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 331    aml_append(ctx, method);
 332}
 333