hw/acpi/cpu_hotplug_acpi_table.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11
  12  * You should have received a copy of the GNU General Public License along
  13  * with this program; if not, see <http://www.gnu.org/licenses/>.
  14  */
  15
  16 #include "qemu/osdep.h"
  17 #include "hw/acpi/cpu_hotplug.h"
  18 #include "hw/i386/pc.h"
  19
  20 #define CPU_EJECT_METHOD "CPEJ"
  21 #define CPU_MAT_METHOD "CPMA"
  22 #define CPU_ON_BITMAP "CPON"
  23 #define CPU_STATUS_METHOD "CPST"
  24 #define CPU_STATUS_MAP "PRS"
  25 #define CPU_SCAN_METHOD "PRSC"
  26
  27 void build_legacy_cpu_hotplug_aml(Aml *ctx, MachineState *machine,
  28                                   uint16_t io_base, uint16_t io_len)
  29 {
  30     Aml *dev;
  31     Aml *crs;
  32     Aml *pkg;
  33     Aml *field;
  34     Aml *method;
  35     Aml *if_ctx;
  36     Aml *else_ctx;
  37     int i, apic_idx;
  38     Aml *sb_scope = aml_scope("_SB");
  39     uint8_t madt_tmpl[8] = {0x00, 0x08, 0x00, 0x00, 0x00, 0, 0, 0};
  40     Aml *cpu_id = aml_arg(0);
  41     Aml *cpu_on = aml_local(0);
  42     Aml *madt = aml_local(1);
  43     Aml *cpus_map = aml_name(CPU_ON_BITMAP);
  44     Aml *zero = aml_int(0);
  45     Aml *one = aml_int(1);
  46     MachineClass *mc = MACHINE_GET_CLASS(machine);
  47     CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
  48     PCMachineState *pcms = PC_MACHINE(machine);
  49
  50     /*
  51      * _MAT method - creates an madt apic buffer
  52      * cpu_id = Arg0 = Processor ID = Local APIC ID
  53      * cpu_on = Local0 = CPON flag for this cpu
  54      * madt = Local1 = Buffer (in madt apic form) to return
  55      */
  56     method = aml_method(CPU_MAT_METHOD, 1, AML_NOTSERIALIZED);
  57     aml_append(method,
  58         aml_store(aml_derefof(aml_index(cpus_map, cpu_id)), cpu_on));
  59     aml_append(method,
  60         aml_store(aml_buffer(sizeof(madt_tmpl), madt_tmpl), madt));
  61     /* Update the processor id, lapic id, and enable/disable status */
  62     aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(2))));
  63     aml_append(method, aml_store(cpu_id, aml_index(madt, aml_int(3))));
  64     aml_append(method, aml_store(cpu_on, aml_index(madt, aml_int(4))));
  65     aml_append(method, aml_return(madt));
  66     aml_append(sb_scope, method);
  67
  68     /*
  69      * _STA method - return ON status of cpu
  70      * cpu_id = Arg0 = Processor ID = Local APIC ID
  71      * cpu_on = Local0 = CPON flag for this cpu
  72      */
  73     method = aml_method(CPU_STATUS_METHOD, 1, AML_NOTSERIALIZED);
  74     aml_append(method,
  75         aml_store(aml_derefof(aml_index(cpus_map, cpu_id)), cpu_on));
  76     if_ctx = aml_if(cpu_on);
  77     {
  78         aml_append(if_ctx, aml_return(aml_int(0xF)));
  79     }
  80     aml_append(method, if_ctx);
  81     else_ctx = aml_else();
  82     {
  83         aml_append(else_ctx, aml_return(zero));
  84     }
  85     aml_append(method, else_ctx);
  86     aml_append(sb_scope, method);
  87
  88     method = aml_method(CPU_EJECT_METHOD, 2, AML_NOTSERIALIZED);
  89     aml_append(method, aml_sleep(200));
  90     aml_append(sb_scope, method);
  91
  92     method = aml_method(CPU_SCAN_METHOD, 0, AML_NOTSERIALIZED);
  93     {
  94         Aml *while_ctx, *if_ctx2, *else_ctx2;
  95         Aml *bus_check_evt = aml_int(1);
  96         Aml *remove_evt = aml_int(3);
  97         Aml *status_map = aml_local(5); /* Local5 = active cpu bitmap */
  98         Aml *byte = aml_local(2); /* Local2 = last read byte from bitmap */
  99         Aml *idx = aml_local(0); /* Processor ID / APIC ID iterator */
 100         Aml *is_cpu_on = aml_local(1); /* Local1 = CPON flag for cpu */
 101         Aml *status = aml_local(3); /* Local3 = active state for cpu */
 102
 103         aml_append(method, aml_store(aml_name(CPU_STATUS_MAP), status_map));
 104         aml_append(method, aml_store(zero, byte));
 105         aml_append(method, aml_store(zero, idx));
 106
 107         /* While (idx < SizeOf(CPON)) */
 108         while_ctx = aml_while(aml_lless(idx, aml_sizeof(cpus_map)));
 109         aml_append(while_ctx,
 110             aml_store(aml_derefof(aml_index(cpus_map, idx)), is_cpu_on));
 111
 112         if_ctx = aml_if(aml_and(idx, aml_int(0x07), NULL));
 113         {
 114             /* Shift down previously read bitmap byte */
 115             aml_append(if_ctx, aml_shiftright(byte, one, byte));
 116         }
 117         aml_append(while_ctx, if_ctx);
 118
 119         else_ctx = aml_else();
 120         {
 121             /* Read next byte from cpu bitmap */
 122             aml_append(else_ctx, aml_store(aml_derefof(aml_index(status_map,
 123                        aml_shiftright(idx, aml_int(3), NULL))), byte));
 124         }
 125         aml_append(while_ctx, else_ctx);
 126
 127         aml_append(while_ctx, aml_store(aml_and(byte, one, NULL), status));
 128         if_ctx = aml_if(aml_lnot(aml_equal(is_cpu_on, status)));
 129         {
 130             /* State change - update CPON with new state */
 131             aml_append(if_ctx, aml_store(status, aml_index(cpus_map, idx)));
 132             if_ctx2 = aml_if(aml_equal(status, one));
 133             {
 134                 aml_append(if_ctx2,
 135                     aml_call2(AML_NOTIFY_METHOD, idx, bus_check_evt));
 136             }
 137             aml_append(if_ctx, if_ctx2);
 138             else_ctx2 = aml_else();
 139             {
 140                 aml_append(else_ctx2,
 141                     aml_call2(AML_NOTIFY_METHOD, idx, remove_evt));
 142             }
 143         }
 144         aml_append(if_ctx, else_ctx2);
 145         aml_append(while_ctx, if_ctx);
 146
 147         aml_append(while_ctx, aml_increment(idx)); /* go to next cpu */
 148         aml_append(method, while_ctx);
 149     }
 150     aml_append(sb_scope, method);
 151
 152     /* The current AML generator can cover the APIC ID range [0..255],
 153      * inclusive, for VCPU hotplug. */
 154     QEMU_BUILD_BUG_ON(ACPI_CPU_HOTPLUG_ID_LIMIT > 256);
 155     g_assert(pcms->apic_id_limit <= ACPI_CPU_HOTPLUG_ID_LIMIT);
 156
 157     /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
 158     dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
 159     aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 160     aml_append(dev,
 161         aml_name_decl("_UID", aml_string("CPU Hotplug resources"))
 162     );
 163     /* device present, functioning, decoding, not shown in UI */
 164     aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
 165     crs = aml_resource_template();
 166     aml_append(crs,
 167         aml_io(AML_DECODE16, io_base, io_base, 1, io_len)
 168     );
 169     aml_append(dev, aml_name_decl("_CRS", crs));
 170     aml_append(sb_scope, dev);
 171     /* declare CPU hotplug MMIO region and PRS field to access it */
 172     aml_append(sb_scope, aml_operation_region(
 173         "PRST", AML_SYSTEM_IO, aml_int(io_base), io_len));
 174     field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
 175     aml_append(field, aml_named_field("PRS", 256));
 176     aml_append(sb_scope, field);
 177
 178     /* build Processor object for each processor */
 179     for (i = 0; i < apic_ids->len; i++) {
 180         int apic_id = apic_ids->cpus[i].arch_id;
 181
 182         assert(apic_id < ACPI_CPU_HOTPLUG_ID_LIMIT);
 183
 184         dev = aml_processor(apic_id, 0, 0, "CP%.02X", apic_id);
 185
 186         method = aml_method("_MAT", 0, AML_NOTSERIALIZED);
 187         aml_append(method,
 188             aml_return(aml_call1(CPU_MAT_METHOD, aml_int(apic_id))));
 189         aml_append(dev, method);
 190
 191         method = aml_method("_STA", 0, AML_NOTSERIALIZED);
 192         aml_append(method,
 193             aml_return(aml_call1(CPU_STATUS_METHOD, aml_int(apic_id))));
 194         aml_append(dev, method);
 195
 196         method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 197         aml_append(method,
 198             aml_return(aml_call2(CPU_EJECT_METHOD, aml_int(apic_id),
 199                 aml_arg(0)))
 200         );
 201         aml_append(dev, method);
 202
 203         aml_append(sb_scope, dev);
 204     }
 205
 206     /* build this code:
 207      *   Method(NTFY, 2) {If (LEqual(Arg0, 0x00)) {Notify(CP00, Arg1)} ...}
 208      */
 209     /* Arg0 = Processor ID = APIC ID */
 210     method = aml_method(AML_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 211     for (i = 0; i < apic_ids->len; i++) {
 212         int apic_id = apic_ids->cpus[i].arch_id;
 213
 214         if_ctx = aml_if(aml_equal(aml_arg(0), aml_int(apic_id)));
 215         aml_append(if_ctx,
 216             aml_notify(aml_name("CP%.02X", apic_id), aml_arg(1))
 217         );
 218         aml_append(method, if_ctx);
 219     }
 220     aml_append(sb_scope, method);
 221
 222     /* build "Name(CPON, Package() { One, One, ..., Zero, Zero, ... })"
 223      *
 224      * Note: The ability to create variable-sized packages was first
 225      * introduced in ACPI 2.0. ACPI 1.0 only allowed fixed-size packages
 226      * ith up to 255 elements. Windows guests up to win2k8 fail when
 227      * VarPackageOp is used.
 228      */
 229     pkg = pcms->apic_id_limit <= 255 ? aml_package(pcms->apic_id_limit) :
 230                                        aml_varpackage(pcms->apic_id_limit);
 231
 232     for (i = 0, apic_idx = 0; i < apic_ids->len; i++) {
 233         int apic_id = apic_ids->cpus[i].arch_id;
 234
 235         for (; apic_idx < apic_id; apic_idx++) {
 236             aml_append(pkg, aml_int(0));
 237         }
 238         aml_append(pkg, aml_int(apic_ids->cpus[i].cpu ? 1 : 0));
 239         apic_idx = apic_id + 1;
 240     }
 241     aml_append(sb_scope, aml_name_decl(CPU_ON_BITMAP, pkg));
 242     g_free(apic_ids);
 243
 244     aml_append(ctx, sb_scope);
 245
 246     method = aml_method("\\_GPE._E02", 0, AML_NOTSERIALIZED);
 247     aml_append(method, aml_call0("\\_SB." CPU_SCAN_METHOD));
 248     aml_append(ctx, method);
 249 }