1/*
2 * QEMU<->ACPI BIOS PCI hotplug interface
3 *
4 * QEMU supports PCI hotplug via ACPI. This module
5 * implements the interface between QEMU and the ACPI BIOS.
6 * Interface specification - see docs/specs/acpi_pci_hotplug.txt
7 *
8 * Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
9 * Copyright (c) 2006 Fabrice Bellard
10 *
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License version 2 as published by the Free Software Foundation.
14 *
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with this library; if not, see <http://www.gnu.org/licenses/>
22 *
23 * Contributions after 2012-01-13 are licensed under the terms of the
24 * GNU GPL, version 2 or (at your option) any later version.
25 */
26
27#include "qemu/osdep.h"
28#include "hw/acpi/pcihp.h"
29
30#include "hw/i386/pc.h"
31#include "hw/pci/pci.h"
32#include "hw/pci/pci_bridge.h"
33#include "hw/acpi/acpi.h"
34#include "exec/address-spaces.h"
35#include "hw/pci/pci_bus.h"
36#include "migration/vmstate.h"
37#include "qapi/error.h"
38#include "qom/qom-qobject.h"
39#include "trace.h"
40
41#define ACPI_PCIHP_ADDR 0xae00
42#define ACPI_PCIHP_SIZE 0x0014
43#define PCI_UP_BASE 0x0000
44#define PCI_DOWN_BASE 0x0004
45#define PCI_EJ_BASE 0x0008
46#define PCI_RMV_BASE 0x000c
47#define PCI_SEL_BASE 0x0010
48
49typedef struct AcpiPciHpFind {
50 int bsel;
51 PCIBus *bus;
52} AcpiPciHpFind;
53
54static int acpi_pcihp_get_bsel(PCIBus *bus)
55{
56 Error *local_err = NULL;
57 uint64_t bsel = object_property_get_uint(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
58 &local_err);
59
60 if (local_err || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
61 if (local_err) {
62 error_free(local_err);
63 }
64 return -1;
65 } else {
66 return bsel;
67 }
68}
69
70/* Assign BSEL property to all buses. In the future, this can be changed
71 * to only assign to buses that support hotplug.
72 */
73static void *acpi_set_bsel(PCIBus *bus, void *opaque)
74{
75 unsigned *bsel_alloc = opaque;
76 unsigned *bus_bsel;
77
78 if (qbus_is_hotpluggable(BUS(bus))) {
79 bus_bsel = g_malloc(sizeof *bus_bsel);
80
81 *bus_bsel = (*bsel_alloc)++;
82 object_property_add_uint32_ptr(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
83 bus_bsel, &error_abort);
84 }
85
86 return bsel_alloc;
87}
88
89static void acpi_set_pci_info(void)
90{
91 static bool bsel_is_set;
92 PCIBus *bus;
93 unsigned bsel_alloc = ACPI_PCIHP_BSEL_DEFAULT;
94
95 if (bsel_is_set) {
96 return;
97 }
98 bsel_is_set = true;
99
100 bus = find_i440fx(); /* TODO: Q35 support */
101 if (bus) {
102 /* Scan all PCI buses. Set property to enable acpi based hotplug. */
103 pci_for_each_bus_depth_first(bus, acpi_set_bsel, NULL, &bsel_alloc);
104 }
105}
106
107static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
108{
109 AcpiPciHpFind *find = opaque;
110 if (find->bsel == acpi_pcihp_get_bsel(bus)) {
111 find->bus = bus;
112 }
113}
114
115static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
116{
117 AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
118
119 if (bsel < 0) {
120 return NULL;
121 }
122
123 pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
124
125 /* Make bsel 0 eject root bus if bsel property is not set,
126 * for compatibility with non acpi setups.
127 * TODO: really needed?
128 */
129 if (!bsel && !find.bus) {
130 find.bus = s->root;
131 }
132 return find.bus;
133}
134
135static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
136{
137 PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
138 DeviceClass *dc = DEVICE_GET_CLASS(dev);
139 /*
140 * ACPI doesn't allow hotplug of bridge devices. Don't allow
141 * hot-unplug of bridge devices unless they were added by hotplug
142 * (and so, not described by acpi).
143 */
144 return (pc->is_bridge && !dev->qdev.hotplugged) || !dc->hotpluggable;
145}
146
147static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
148{
149 HotplugHandler *hotplug_ctrl;
150 BusChild *kid, *next;
151 int slot = ctz32(slots);
152 PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
153
154 trace_acpi_pci_eject_slot(bsel, slot);
155
156 if (!bus) {
157 return;
158 }
159
160 /* Mark request as complete */
161 s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
162 s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
163
164 QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
165 DeviceState *qdev = kid->child;
166 PCIDevice *dev = PCI_DEVICE(qdev);
167 if (PCI_SLOT(dev->devfn) == slot) {
168 if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
169 hotplug_ctrl = qdev_get_hotplug_handler(qdev);
170 hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort);
171 object_unparent(OBJECT(qdev));
172 }
173 }
174 }
175}
176
177static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
178{
179 BusChild *kid, *next;
180 PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
181
182 /* Execute any pending removes during reset */
183 while (s->acpi_pcihp_pci_status[bsel].down) {
184 acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
185 }
186
187 s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
188
189 if (!bus) {
190 return;
191 }
192 QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
193 DeviceState *qdev = kid->child;
194 PCIDevice *pdev = PCI_DEVICE(qdev);
195 int slot = PCI_SLOT(pdev->devfn);
196
197 if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
198 s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
199 }
200 }
201}
202
203static void acpi_pcihp_update(AcpiPciHpState *s)
204{
205 int i;
206
207 for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
208 acpi_pcihp_update_hotplug_bus(s, i);
209 }
210}
211
212void acpi_pcihp_reset(AcpiPciHpState *s)
213{
214 acpi_set_pci_info();
215 acpi_pcihp_update(s);
216}
217
218void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
219 DeviceState *dev, Error **errp)
220{
221 /* Only hotplugged devices need the hotplug capability. */
222 if (dev->hotplugged &&
223 acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev))) < 0) {
224 error_setg(errp, "Unsupported bus. Bus doesn't have property '"
225 ACPI_PCIHP_PROP_BSEL "' set");
226 return;
227 }
228}
229
230void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
231 DeviceState *dev, Error **errp)
232{
233 PCIDevice *pdev = PCI_DEVICE(dev);
234 int slot = PCI_SLOT(pdev->devfn);
235 int bsel;
236
237 /* Don't send event when device is enabled during qemu machine creation:
238 * it is present on boot, no hotplug event is necessary. We do send an
239 * event when the device is disabled later. */
240 if (!dev->hotplugged) {
241 /*
242 * Overwrite the default hotplug handler with the ACPI PCI one
243 * for cold plugged bridges only.
244 */
245 if (!s->legacy_piix &&
246 object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
247 PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
248
249 qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev),
250 &error_abort);
251 /* We don't have to overwrite any other hotplug handler yet */
252 assert(QLIST_EMPTY(&sec->child));
253 }
254
255 return;
256 }
257
258 bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
259 g_assert(bsel >= 0);
260 s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
261 acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
262}
263
264void acpi_pcihp_device_unplug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
265 DeviceState *dev, Error **errp)
266{
267 trace_acpi_pci_unplug(PCI_SLOT(PCI_DEVICE(dev)->devfn),
268 acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev))));
269 object_property_set_bool(OBJECT(dev), false, "realized", NULL);
270}
271
272void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,
273 AcpiPciHpState *s, DeviceState *dev,
274 Error **errp)
275{
276 PCIDevice *pdev = PCI_DEVICE(dev);
277 int slot = PCI_SLOT(pdev->devfn);
278 int bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
279
280 trace_acpi_pci_unplug_request(bsel, slot);
281
282 if (bsel < 0) {
283 error_setg(errp, "Unsupported bus. Bus doesn't have property '"
284 ACPI_PCIHP_PROP_BSEL "' set");
285 return;
286 }
287
288 s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
289 acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
290}
291
292static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
293{
294 AcpiPciHpState *s = opaque;
295 uint32_t val = 0;
296 int bsel = s->hotplug_select;
297
298 if (bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
299 return 0;
300 }
301
302 switch (addr) {
303 case PCI_UP_BASE:
304 val = s->acpi_pcihp_pci_status[bsel].up;
305 if (!s->legacy_piix) {
306 s->acpi_pcihp_pci_status[bsel].up = 0;
307 }
308 trace_acpi_pci_up_read(val);
309 break;
310 case PCI_DOWN_BASE:
311 val = s->acpi_pcihp_pci_status[bsel].down;
312 trace_acpi_pci_down_read(val);
313 break;
314 case PCI_EJ_BASE:
315 /* No feature defined yet */
316 trace_acpi_pci_features_read(val);
317 break;
318 case PCI_RMV_BASE:
319 val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
320 trace_acpi_pci_rmv_read(val);
321 break;
322 case PCI_SEL_BASE:
323 val = s->hotplug_select;
324 trace_acpi_pci_sel_read(val);
325 default:
326 break;
327 }
328
329 return val;
330}
331
332static void pci_write(void *opaque, hwaddr addr, uint64_t data,
333 unsigned int size)
334{
335 AcpiPciHpState *s = opaque;
336 switch (addr) {
337 case PCI_EJ_BASE:
338 if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
339 break;
340 }
341 acpi_pcihp_eject_slot(s, s->hotplug_select, data);
342 trace_acpi_pci_ej_write(addr, data);
343 break;
344 case PCI_SEL_BASE:
345 s->hotplug_select = s->legacy_piix ? ACPI_PCIHP_BSEL_DEFAULT : data;
346 trace_acpi_pci_sel_write(addr, data);
347 default:
348 break;
349 }
350}
351
352static const MemoryRegionOps acpi_pcihp_io_ops = {
353 .read = pci_read,
354 .write = pci_write,
355 .endianness = DEVICE_LITTLE_ENDIAN,
356 .valid = {
357 .min_access_size = 4,
358 .max_access_size = 4,
359 },
360};
361
362void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
363 MemoryRegion *address_space_io, bool bridges_enabled)
364{
365 s->io_len = ACPI_PCIHP_SIZE;
366 s->io_base = ACPI_PCIHP_ADDR;
367
368 s->root= root_bus;
369 s->legacy_piix = !bridges_enabled;
370
371 memory_region_init_io(&s->io, owner, &acpi_pcihp_io_ops, s,
372 "acpi-pci-hotplug", s->io_len);
373 memory_region_add_subregion(address_space_io, s->io_base, &s->io);
374
375 object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_BASE_PROP, &s->io_base,
376 &error_abort);
377 object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_LEN_PROP, &s->io_len,
378 &error_abort);
379}
380
381const VMStateDescription vmstate_acpi_pcihp_pci_status = {
382 .name = "acpi_pcihp_pci_status",
383 .version_id = 1,
384 .minimum_version_id = 1,
385 .fields = (VMStateField[]) {
386 VMSTATE_UINT32(up, AcpiPciHpPciStatus),
387 VMSTATE_UINT32(down, AcpiPciHpPciStatus),
388 VMSTATE_END_OF_LIST()
389 }
390};
391