xref: /openbmc/qemu/hw/acpi/piix4.c (revision b2c623a3)
1 /*
2  * ACPI implementation
3  *
4  * Copyright (c) 2006 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License version 2 as published by the Free Software Foundation.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, see <http://www.gnu.org/licenses/>
17  *
18  * Contributions after 2012-01-13 are licensed under the terms of the
19  * GNU GPL, version 2 or (at your option) any later version.
20  */
21 #include "hw/hw.h"
22 #include "hw/i386/pc.h"
23 #include "hw/isa/apm.h"
24 #include "hw/i2c/pm_smbus.h"
25 #include "hw/pci/pci.h"
26 #include "hw/acpi/acpi.h"
27 #include "sysemu/sysemu.h"
28 #include "qemu/range.h"
29 #include "exec/ioport.h"
30 #include "hw/nvram/fw_cfg.h"
31 #include "exec/address-spaces.h"
32 #include "hw/acpi/piix4.h"
33 #include "hw/acpi/pcihp.h"
34 #include "hw/acpi/cpu_hotplug.h"
35 
36 //#define DEBUG
37 
38 #ifdef DEBUG
39 # define PIIX4_DPRINTF(format, ...)     printf(format, ## __VA_ARGS__)
40 #else
41 # define PIIX4_DPRINTF(format, ...)     do { } while (0)
42 #endif
43 
44 #define GPE_BASE 0xafe0
45 #define GPE_LEN 4
46 
47 #define PCI_HOTPLUG_ADDR 0xae00
48 #define PCI_HOTPLUG_SIZE 0x000f
49 #define PCI_UP_BASE 0xae00
50 #define PCI_DOWN_BASE 0xae04
51 #define PCI_EJ_BASE 0xae08
52 #define PCI_RMV_BASE 0xae0c
53 
54 #define PIIX4_PCI_HOTPLUG_STATUS 2
55 
56 struct pci_status {
57     uint32_t up; /* deprecated, maintained for migration compatibility */
58     uint32_t down;
59 };
60 
61 typedef struct PIIX4PMState {
62     /*< private >*/
63     PCIDevice parent_obj;
64     /*< public >*/
65 
66     MemoryRegion io;
67     uint32_t io_base;
68 
69     MemoryRegion io_gpe;
70     ACPIREGS ar;
71 
72     APMState apm;
73 
74     PMSMBus smb;
75     uint32_t smb_io_base;
76 
77     qemu_irq irq;
78     qemu_irq smi_irq;
79     int kvm_enabled;
80     Notifier machine_ready;
81     Notifier powerdown_notifier;
82 
83     /* for legacy pci hotplug (compatible with qemu 1.6 and older) */
84     MemoryRegion io_pci;
85     struct pci_status pci0_status;
86     uint32_t pci0_hotplug_enable;
87     uint32_t pci0_slot_device_present;
88 
89     /* for new pci hotplug (with PCI2PCI bridge support) */
90     AcpiPciHpState acpi_pci_hotplug;
91     bool use_acpi_pci_hotplug;
92 
93     uint8_t disable_s3;
94     uint8_t disable_s4;
95     uint8_t s4_val;
96 
97     AcpiCpuHotplug gpe_cpu;
98     Notifier cpu_added_notifier;
99 } PIIX4PMState;
100 
101 #define TYPE_PIIX4_PM "PIIX4_PM"
102 
103 #define PIIX4_PM(obj) \
104     OBJECT_CHECK(PIIX4PMState, (obj), TYPE_PIIX4_PM)
105 
106 static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
107                                            PCIBus *bus, PIIX4PMState *s);
108 
109 #define ACPI_ENABLE 0xf1
110 #define ACPI_DISABLE 0xf0
111 
112 static void pm_tmr_timer(ACPIREGS *ar)
113 {
114     PIIX4PMState *s = container_of(ar, PIIX4PMState, ar);
115     acpi_update_sci(&s->ar, s->irq);
116 }
117 
118 static void apm_ctrl_changed(uint32_t val, void *arg)
119 {
120     PIIX4PMState *s = arg;
121     PCIDevice *d = PCI_DEVICE(s);
122 
123     /* ACPI specs 3.0, 4.7.2.5 */
124     acpi_pm1_cnt_update(&s->ar, val == ACPI_ENABLE, val == ACPI_DISABLE);
125 
126     if (d->config[0x5b] & (1 << 1)) {
127         if (s->smi_irq) {
128             qemu_irq_raise(s->smi_irq);
129         }
130     }
131 }
132 
133 static void pm_io_space_update(PIIX4PMState *s)
134 {
135     PCIDevice *d = PCI_DEVICE(s);
136 
137     s->io_base = le32_to_cpu(*(uint32_t *)(d->config + 0x40));
138     s->io_base &= 0xffc0;
139 
140     memory_region_transaction_begin();
141     memory_region_set_enabled(&s->io, d->config[0x80] & 1);
142     memory_region_set_address(&s->io, s->io_base);
143     memory_region_transaction_commit();
144 }
145 
146 static void smbus_io_space_update(PIIX4PMState *s)
147 {
148     PCIDevice *d = PCI_DEVICE(s);
149 
150     s->smb_io_base = le32_to_cpu(*(uint32_t *)(d->config + 0x90));
151     s->smb_io_base &= 0xffc0;
152 
153     memory_region_transaction_begin();
154     memory_region_set_enabled(&s->smb.io, d->config[0xd2] & 1);
155     memory_region_set_address(&s->smb.io, s->smb_io_base);
156     memory_region_transaction_commit();
157 }
158 
159 static void pm_write_config(PCIDevice *d,
160                             uint32_t address, uint32_t val, int len)
161 {
162     pci_default_write_config(d, address, val, len);
163     if (range_covers_byte(address, len, 0x80) ||
164         ranges_overlap(address, len, 0x40, 4)) {
165         pm_io_space_update((PIIX4PMState *)d);
166     }
167     if (range_covers_byte(address, len, 0xd2) ||
168         ranges_overlap(address, len, 0x90, 4)) {
169         smbus_io_space_update((PIIX4PMState *)d);
170     }
171 }
172 
173 static void vmstate_pci_status_pre_save(void *opaque)
174 {
175     struct pci_status *pci0_status = opaque;
176     PIIX4PMState *s = container_of(pci0_status, PIIX4PMState, pci0_status);
177 
178     /* We no longer track up, so build a safe value for migrating
179      * to a version that still does... of course these might get lost
180      * by an old buggy implementation, but we try. */
181     pci0_status->up = s->pci0_slot_device_present & s->pci0_hotplug_enable;
182 }
183 
184 static int vmstate_acpi_post_load(void *opaque, int version_id)
185 {
186     PIIX4PMState *s = opaque;
187 
188     pm_io_space_update(s);
189     return 0;
190 }
191 
192 #define VMSTATE_GPE_ARRAY(_field, _state)                            \
193  {                                                                   \
194      .name       = (stringify(_field)),                              \
195      .version_id = 0,                                                \
196      .info       = &vmstate_info_uint16,                             \
197      .size       = sizeof(uint16_t),                                 \
198      .flags      = VMS_SINGLE | VMS_POINTER,                         \
199      .offset     = vmstate_offset_pointer(_state, _field, uint8_t),  \
200  }
201 
202 static const VMStateDescription vmstate_gpe = {
203     .name = "gpe",
204     .version_id = 1,
205     .minimum_version_id = 1,
206     .minimum_version_id_old = 1,
207     .fields      = (VMStateField []) {
208         VMSTATE_GPE_ARRAY(sts, ACPIGPE),
209         VMSTATE_GPE_ARRAY(en, ACPIGPE),
210         VMSTATE_END_OF_LIST()
211     }
212 };
213 
214 static const VMStateDescription vmstate_pci_status = {
215     .name = "pci_status",
216     .version_id = 1,
217     .minimum_version_id = 1,
218     .minimum_version_id_old = 1,
219     .pre_save = vmstate_pci_status_pre_save,
220     .fields      = (VMStateField []) {
221         VMSTATE_UINT32(up, struct pci_status),
222         VMSTATE_UINT32(down, struct pci_status),
223         VMSTATE_END_OF_LIST()
224     }
225 };
226 
227 static int acpi_load_old(QEMUFile *f, void *opaque, int version_id)
228 {
229     PIIX4PMState *s = opaque;
230     int ret, i;
231     uint16_t temp;
232 
233     ret = pci_device_load(PCI_DEVICE(s), f);
234     if (ret < 0) {
235         return ret;
236     }
237     qemu_get_be16s(f, &s->ar.pm1.evt.sts);
238     qemu_get_be16s(f, &s->ar.pm1.evt.en);
239     qemu_get_be16s(f, &s->ar.pm1.cnt.cnt);
240 
241     ret = vmstate_load_state(f, &vmstate_apm, &s->apm, 1);
242     if (ret) {
243         return ret;
244     }
245 
246     timer_get(f, s->ar.tmr.timer);
247     qemu_get_sbe64s(f, &s->ar.tmr.overflow_time);
248 
249     qemu_get_be16s(f, (uint16_t *)s->ar.gpe.sts);
250     for (i = 0; i < 3; i++) {
251         qemu_get_be16s(f, &temp);
252     }
253 
254     qemu_get_be16s(f, (uint16_t *)s->ar.gpe.en);
255     for (i = 0; i < 3; i++) {
256         qemu_get_be16s(f, &temp);
257     }
258 
259     ret = vmstate_load_state(f, &vmstate_pci_status, &s->pci0_status, 1);
260     return ret;
261 }
262 
263 static bool vmstate_test_use_acpi_pci_hotplug(void *opaque, int version_id)
264 {
265     PIIX4PMState *s = opaque;
266     return s->use_acpi_pci_hotplug;
267 }
268 
269 static bool vmstate_test_no_use_acpi_pci_hotplug(void *opaque, int version_id)
270 {
271     PIIX4PMState *s = opaque;
272     return !s->use_acpi_pci_hotplug;
273 }
274 
275 /* qemu-kvm 1.2 uses version 3 but advertised as 2
276  * To support incoming qemu-kvm 1.2 migration, change version_id
277  * and minimum_version_id to 2 below (which breaks migration from
278  * qemu 1.2).
279  *
280  */
281 static const VMStateDescription vmstate_acpi = {
282     .name = "piix4_pm",
283     .version_id = 3,
284     .minimum_version_id = 3,
285     .minimum_version_id_old = 1,
286     .load_state_old = acpi_load_old,
287     .post_load = vmstate_acpi_post_load,
288     .fields      = (VMStateField []) {
289         VMSTATE_PCI_DEVICE(parent_obj, PIIX4PMState),
290         VMSTATE_UINT16(ar.pm1.evt.sts, PIIX4PMState),
291         VMSTATE_UINT16(ar.pm1.evt.en, PIIX4PMState),
292         VMSTATE_UINT16(ar.pm1.cnt.cnt, PIIX4PMState),
293         VMSTATE_STRUCT(apm, PIIX4PMState, 0, vmstate_apm, APMState),
294         VMSTATE_TIMER(ar.tmr.timer, PIIX4PMState),
295         VMSTATE_INT64(ar.tmr.overflow_time, PIIX4PMState),
296         VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
297         VMSTATE_STRUCT_TEST(pci0_status, PIIX4PMState,
298                             vmstate_test_no_use_acpi_pci_hotplug,
299                             2, vmstate_pci_status,
300                             struct pci_status),
301         VMSTATE_PCI_HOTPLUG(acpi_pci_hotplug, PIIX4PMState,
302                             vmstate_test_use_acpi_pci_hotplug),
303         VMSTATE_END_OF_LIST()
304     }
305 };
306 
307 static void acpi_piix_eject_slot(PIIX4PMState *s, unsigned slots)
308 {
309     BusChild *kid, *next;
310     BusState *bus = qdev_get_parent_bus(DEVICE(s));
311     int slot = ffs(slots) - 1;
312     bool slot_free = true;
313 
314     /* Mark request as complete */
315     s->pci0_status.down &= ~(1U << slot);
316 
317     QTAILQ_FOREACH_SAFE(kid, &bus->children, sibling, next) {
318         DeviceState *qdev = kid->child;
319         PCIDevice *dev = PCI_DEVICE(qdev);
320         PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
321         if (PCI_SLOT(dev->devfn) == slot) {
322             if (pc->no_hotplug) {
323                 slot_free = false;
324             } else {
325                 object_unparent(OBJECT(qdev));
326             }
327         }
328     }
329     if (slot_free) {
330         s->pci0_slot_device_present &= ~(1U << slot);
331     }
332 }
333 
334 static void piix4_update_hotplug(PIIX4PMState *s)
335 {
336     BusState *bus = qdev_get_parent_bus(DEVICE(s));
337     BusChild *kid, *next;
338 
339     /* Execute any pending removes during reset */
340     while (s->pci0_status.down) {
341         acpi_piix_eject_slot(s, s->pci0_status.down);
342     }
343 
344     s->pci0_hotplug_enable = ~0;
345     s->pci0_slot_device_present = 0;
346 
347     QTAILQ_FOREACH_SAFE(kid, &bus->children, sibling, next) {
348         DeviceState *qdev = kid->child;
349         PCIDevice *pdev = PCI_DEVICE(qdev);
350         PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(pdev);
351         int slot = PCI_SLOT(pdev->devfn);
352 
353         if (pc->no_hotplug) {
354             s->pci0_hotplug_enable &= ~(1U << slot);
355         }
356 
357         s->pci0_slot_device_present |= (1U << slot);
358     }
359 }
360 
361 static void piix4_reset(void *opaque)
362 {
363     PIIX4PMState *s = opaque;
364     PCIDevice *d = PCI_DEVICE(s);
365     uint8_t *pci_conf = d->config;
366 
367     pci_conf[0x58] = 0;
368     pci_conf[0x59] = 0;
369     pci_conf[0x5a] = 0;
370     pci_conf[0x5b] = 0;
371 
372     pci_conf[0x40] = 0x01; /* PM io base read only bit */
373     pci_conf[0x80] = 0;
374 
375     if (s->kvm_enabled) {
376         /* Mark SMM as already inited (until KVM supports SMM). */
377         pci_conf[0x5B] = 0x02;
378     }
379     pm_io_space_update(s);
380     if (s->use_acpi_pci_hotplug) {
381         acpi_pcihp_reset(&s->acpi_pci_hotplug);
382     } else {
383         piix4_update_hotplug(s);
384     }
385 }
386 
387 static void piix4_pm_powerdown_req(Notifier *n, void *opaque)
388 {
389     PIIX4PMState *s = container_of(n, PIIX4PMState, powerdown_notifier);
390 
391     assert(s != NULL);
392     acpi_pm1_evt_power_down(&s->ar);
393 }
394 
395 static int piix4_acpi_pci_hotplug(DeviceState *qdev, PCIDevice *dev,
396                                   PCIHotplugState state)
397 {
398     PIIX4PMState *s = PIIX4_PM(qdev);
399     int ret = acpi_pcihp_device_hotplug(&s->acpi_pci_hotplug, dev, state);
400     if (ret < 0) {
401         return ret;
402     }
403     s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
404 
405     acpi_update_sci(&s->ar, s->irq);
406     return 0;
407 }
408 
409 static void piix4_update_bus_hotplug(PCIBus *bus, void *opaque)
410 {
411     PIIX4PMState *s = opaque;
412     pci_bus_hotplug(bus, piix4_acpi_pci_hotplug, DEVICE(s));
413 }
414 
415 static void piix4_pm_machine_ready(Notifier *n, void *opaque)
416 {
417     PIIX4PMState *s = container_of(n, PIIX4PMState, machine_ready);
418     PCIDevice *d = PCI_DEVICE(s);
419     MemoryRegion *io_as = pci_address_space_io(d);
420     uint8_t *pci_conf;
421 
422     pci_conf = d->config;
423     pci_conf[0x5f] = 0x10 |
424         (memory_region_present(io_as, 0x378) ? 0x80 : 0);
425     pci_conf[0x63] = 0x60;
426     pci_conf[0x67] = (memory_region_present(io_as, 0x3f8) ? 0x08 : 0) |
427         (memory_region_present(io_as, 0x2f8) ? 0x90 : 0);
428 
429     if (s->use_acpi_pci_hotplug) {
430         pci_for_each_bus(d->bus, piix4_update_bus_hotplug, s);
431     }
432 }
433 
434 static void piix4_pm_add_propeties(PIIX4PMState *s)
435 {
436     static const uint8_t acpi_enable_cmd = ACPI_ENABLE;
437     static const uint8_t acpi_disable_cmd = ACPI_DISABLE;
438     static const uint32_t gpe0_blk = GPE_BASE;
439     static const uint32_t gpe0_blk_len = GPE_LEN;
440     static const uint16_t sci_int = 9;
441 
442     object_property_add_uint8_ptr(OBJECT(s), ACPI_PM_PROP_ACPI_ENABLE_CMD,
443                                   &acpi_enable_cmd, NULL);
444     object_property_add_uint8_ptr(OBJECT(s), ACPI_PM_PROP_ACPI_DISABLE_CMD,
445                                   &acpi_disable_cmd, NULL);
446     object_property_add_uint32_ptr(OBJECT(s), ACPI_PM_PROP_GPE0_BLK,
447                                   &gpe0_blk, NULL);
448     object_property_add_uint32_ptr(OBJECT(s), ACPI_PM_PROP_GPE0_BLK_LEN,
449                                   &gpe0_blk_len, NULL);
450     object_property_add_uint16_ptr(OBJECT(s), ACPI_PM_PROP_SCI_INT,
451                                   &sci_int, NULL);
452     object_property_add_uint32_ptr(OBJECT(s), ACPI_PM_PROP_PM_IO_BASE,
453                                   &s->io_base, NULL);
454 }
455 
456 static int piix4_pm_initfn(PCIDevice *dev)
457 {
458     PIIX4PMState *s = PIIX4_PM(dev);
459     uint8_t *pci_conf;
460 
461     pci_conf = dev->config;
462     pci_conf[0x06] = 0x80;
463     pci_conf[0x07] = 0x02;
464     pci_conf[0x09] = 0x00;
465     pci_conf[0x3d] = 0x01; // interrupt pin 1
466 
467     /* APM */
468     apm_init(dev, &s->apm, apm_ctrl_changed, s);
469 
470     if (s->kvm_enabled) {
471         /* Mark SMM as already inited to prevent SMM from running.  KVM does not
472          * support SMM mode. */
473         pci_conf[0x5B] = 0x02;
474     }
475 
476     /* XXX: which specification is used ? The i82731AB has different
477        mappings */
478     pci_conf[0x90] = s->smb_io_base | 1;
479     pci_conf[0x91] = s->smb_io_base >> 8;
480     pci_conf[0xd2] = 0x09;
481     pm_smbus_init(DEVICE(dev), &s->smb);
482     memory_region_set_enabled(&s->smb.io, pci_conf[0xd2] & 1);
483     memory_region_add_subregion(pci_address_space_io(dev),
484                                 s->smb_io_base, &s->smb.io);
485 
486     memory_region_init(&s->io, OBJECT(s), "piix4-pm", 64);
487     memory_region_set_enabled(&s->io, false);
488     memory_region_add_subregion(pci_address_space_io(dev),
489                                 0, &s->io);
490 
491     acpi_pm_tmr_init(&s->ar, pm_tmr_timer, &s->io);
492     acpi_pm1_evt_init(&s->ar, pm_tmr_timer, &s->io);
493     acpi_pm1_cnt_init(&s->ar, &s->io, s->s4_val);
494     acpi_gpe_init(&s->ar, GPE_LEN);
495 
496     s->powerdown_notifier.notify = piix4_pm_powerdown_req;
497     qemu_register_powerdown_notifier(&s->powerdown_notifier);
498 
499     s->machine_ready.notify = piix4_pm_machine_ready;
500     qemu_add_machine_init_done_notifier(&s->machine_ready);
501     qemu_register_reset(piix4_reset, s);
502 
503     piix4_acpi_system_hot_add_init(pci_address_space_io(dev), dev->bus, s);
504 
505     piix4_pm_add_propeties(s);
506     return 0;
507 }
508 
509 Object *piix4_pm_find(void)
510 {
511     bool ambig;
512     Object *o = object_resolve_path_type("", TYPE_PIIX4_PM, &ambig);
513 
514     if (ambig || !o) {
515         return NULL;
516     }
517     return o;
518 }
519 
520 i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
521                        qemu_irq sci_irq, qemu_irq smi_irq,
522                        int kvm_enabled, FWCfgState *fw_cfg)
523 {
524     DeviceState *dev;
525     PIIX4PMState *s;
526 
527     dev = DEVICE(pci_create(bus, devfn, TYPE_PIIX4_PM));
528     qdev_prop_set_uint32(dev, "smb_io_base", smb_io_base);
529 
530     s = PIIX4_PM(dev);
531     s->irq = sci_irq;
532     s->smi_irq = smi_irq;
533     s->kvm_enabled = kvm_enabled;
534 
535     qdev_init_nofail(dev);
536 
537     if (fw_cfg) {
538         uint8_t suspend[6] = {128, 0, 0, 129, 128, 128};
539         suspend[3] = 1 | ((!s->disable_s3) << 7);
540         suspend[4] = s->s4_val | ((!s->disable_s4) << 7);
541 
542         fw_cfg_add_file(fw_cfg, "etc/system-states", g_memdup(suspend, 6), 6);
543     }
544 
545     return s->smb.smbus;
546 }
547 
548 static Property piix4_pm_properties[] = {
549     DEFINE_PROP_UINT32("smb_io_base", PIIX4PMState, smb_io_base, 0),
550     DEFINE_PROP_UINT8(ACPI_PM_PROP_S3_DISABLED, PIIX4PMState, disable_s3, 0),
551     DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_DISABLED, PIIX4PMState, disable_s4, 0),
552     DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_VAL, PIIX4PMState, s4_val, 2),
553     DEFINE_PROP_BOOL("acpi-pci-hotplug-with-bridge-support", PIIX4PMState,
554                      use_acpi_pci_hotplug, true),
555     DEFINE_PROP_END_OF_LIST(),
556 };
557 
558 static void piix4_pm_class_init(ObjectClass *klass, void *data)
559 {
560     DeviceClass *dc = DEVICE_CLASS(klass);
561     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
562 
563     k->no_hotplug = 1;
564     k->init = piix4_pm_initfn;
565     k->config_write = pm_write_config;
566     k->vendor_id = PCI_VENDOR_ID_INTEL;
567     k->device_id = PCI_DEVICE_ID_INTEL_82371AB_3;
568     k->revision = 0x03;
569     k->class_id = PCI_CLASS_BRIDGE_OTHER;
570     dc->desc = "PM";
571     dc->vmsd = &vmstate_acpi;
572     dc->props = piix4_pm_properties;
573     /*
574      * Reason: part of PIIX4 southbridge, needs to be wired up,
575      * e.g. by mips_malta_init()
576      */
577     dc->cannot_instantiate_with_device_add_yet = true;
578 }
579 
580 static const TypeInfo piix4_pm_info = {
581     .name          = TYPE_PIIX4_PM,
582     .parent        = TYPE_PCI_DEVICE,
583     .instance_size = sizeof(PIIX4PMState),
584     .class_init    = piix4_pm_class_init,
585 };
586 
587 static void piix4_pm_register_types(void)
588 {
589     type_register_static(&piix4_pm_info);
590 }
591 
592 type_init(piix4_pm_register_types)
593 
594 static uint64_t gpe_readb(void *opaque, hwaddr addr, unsigned width)
595 {
596     PIIX4PMState *s = opaque;
597     uint32_t val = acpi_gpe_ioport_readb(&s->ar, addr);
598 
599     PIIX4_DPRINTF("gpe read %" HWADDR_PRIx " == %" PRIu32 "\n", addr, val);
600     return val;
601 }
602 
603 static void gpe_writeb(void *opaque, hwaddr addr, uint64_t val,
604                        unsigned width)
605 {
606     PIIX4PMState *s = opaque;
607 
608     acpi_gpe_ioport_writeb(&s->ar, addr, val);
609     acpi_update_sci(&s->ar, s->irq);
610 
611     PIIX4_DPRINTF("gpe write %" HWADDR_PRIx " <== %" PRIu64 "\n", addr, val);
612 }
613 
614 static const MemoryRegionOps piix4_gpe_ops = {
615     .read = gpe_readb,
616     .write = gpe_writeb,
617     .valid.min_access_size = 1,
618     .valid.max_access_size = 4,
619     .impl.min_access_size = 1,
620     .impl.max_access_size = 1,
621     .endianness = DEVICE_LITTLE_ENDIAN,
622 };
623 
624 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
625 {
626     PIIX4PMState *s = opaque;
627     uint32_t val = 0;
628 
629     switch (addr) {
630     case PCI_UP_BASE - PCI_HOTPLUG_ADDR:
631         /* Manufacture an "up" value to cause a device check on any hotplug
632          * slot with a device.  Extra device checks are harmless. */
633         val = s->pci0_slot_device_present & s->pci0_hotplug_enable;
634         PIIX4_DPRINTF("pci_up_read %" PRIu32 "\n", val);
635         break;
636     case PCI_DOWN_BASE - PCI_HOTPLUG_ADDR:
637         val = s->pci0_status.down;
638         PIIX4_DPRINTF("pci_down_read %" PRIu32 "\n", val);
639         break;
640     case PCI_EJ_BASE - PCI_HOTPLUG_ADDR:
641         /* No feature defined yet */
642         PIIX4_DPRINTF("pci_features_read %" PRIu32 "\n", val);
643         break;
644     case PCI_RMV_BASE - PCI_HOTPLUG_ADDR:
645         val = s->pci0_hotplug_enable;
646         break;
647     default:
648         break;
649     }
650 
651     return val;
652 }
653 
654 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
655                       unsigned int size)
656 {
657     switch (addr) {
658     case PCI_EJ_BASE - PCI_HOTPLUG_ADDR:
659         acpi_piix_eject_slot(opaque, (uint32_t)data);
660         PIIX4_DPRINTF("pciej write %" HWADDR_PRIx " <== %" PRIu64 "\n",
661                       addr, data);
662         break;
663     default:
664         break;
665     }
666 }
667 
668 static const MemoryRegionOps piix4_pci_ops = {
669     .read = pci_read,
670     .write = pci_write,
671     .endianness = DEVICE_LITTLE_ENDIAN,
672     .valid = {
673         .min_access_size = 4,
674         .max_access_size = 4,
675     },
676 };
677 
678 static void piix4_cpu_added_req(Notifier *n, void *opaque)
679 {
680     PIIX4PMState *s = container_of(n, PIIX4PMState, cpu_added_notifier);
681 
682     assert(s != NULL);
683     AcpiCpuHotplug_add(&s->ar.gpe, &s->gpe_cpu, CPU(opaque));
684     acpi_update_sci(&s->ar, s->irq);
685 }
686 
687 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
688                                 PCIHotplugState state);
689 
690 static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
691                                            PCIBus *bus, PIIX4PMState *s)
692 {
693     memory_region_init_io(&s->io_gpe, OBJECT(s), &piix4_gpe_ops, s,
694                           "acpi-gpe0", GPE_LEN);
695     memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
696 
697     if (s->use_acpi_pci_hotplug) {
698         acpi_pcihp_init(&s->acpi_pci_hotplug, bus, parent);
699     } else {
700         memory_region_init_io(&s->io_pci, OBJECT(s), &piix4_pci_ops, s,
701                               "acpi-pci-hotplug", PCI_HOTPLUG_SIZE);
702         memory_region_add_subregion(parent, PCI_HOTPLUG_ADDR,
703                                     &s->io_pci);
704         pci_bus_hotplug(bus, piix4_device_hotplug, DEVICE(s));
705     }
706 
707     AcpiCpuHotplug_init(parent, OBJECT(s), &s->gpe_cpu,
708                         PIIX4_CPU_HOTPLUG_IO_BASE);
709     s->cpu_added_notifier.notify = piix4_cpu_added_req;
710     qemu_register_cpu_added_notifier(&s->cpu_added_notifier);
711 }
712 
713 static void enable_device(PIIX4PMState *s, int slot)
714 {
715     s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
716     s->pci0_slot_device_present |= (1U << slot);
717 }
718 
719 static void disable_device(PIIX4PMState *s, int slot)
720 {
721     s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
722     s->pci0_status.down |= (1U << slot);
723 }
724 
725 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
726 				PCIHotplugState state)
727 {
728     int slot = PCI_SLOT(dev->devfn);
729     PIIX4PMState *s = PIIX4_PM(qdev);
730 
731     /* Don't send event when device is enabled during qemu machine creation:
732      * it is present on boot, no hotplug event is necessary. We do send an
733      * event when the device is disabled later. */
734     if (state == PCI_COLDPLUG_ENABLED) {
735         s->pci0_slot_device_present |= (1U << slot);
736         return 0;
737     }
738 
739     if (state == PCI_HOTPLUG_ENABLED) {
740         enable_device(s, slot);
741     } else {
742         disable_device(s, slot);
743     }
744 
745     acpi_update_sci(&s->ar, s->irq);
746 
747     return 0;
748 }
749