xref: /openbmc/qemu/hw/pci/pcie.c (revision 99f31832)
1 /*
2  * pcie.c
3  *
4  * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
5  *                    VA Linux Systems Japan K.K.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with this program; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qapi/error.h"
23 #include "qemu-common.h"
24 #include "hw/pci/pci_bridge.h"
25 #include "hw/pci/pcie.h"
26 #include "hw/pci/msix.h"
27 #include "hw/pci/msi.h"
28 #include "hw/pci/pci_bus.h"
29 #include "hw/pci/pcie_regs.h"
30 #include "qemu/range.h"
31 
32 //#define DEBUG_PCIE
33 #ifdef DEBUG_PCIE
34 # define PCIE_DPRINTF(fmt, ...)                                         \
35     fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
36 #else
37 # define PCIE_DPRINTF(fmt, ...) do {} while (0)
38 #endif
39 #define PCIE_DEV_PRINTF(dev, fmt, ...)                                  \
40     PCIE_DPRINTF("%s:%x "fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
41 
42 
43 /***************************************************************************
44  * pci express capability helper functions
45  */
46 
47 static void
48 pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type, uint8_t version)
49 {
50     uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
51     uint8_t *cmask = dev->cmask + dev->exp.exp_cap;
52 
53     /* capability register
54     interrupt message number defaults to 0 */
55     pci_set_word(exp_cap + PCI_EXP_FLAGS,
56                  ((type << PCI_EXP_FLAGS_TYPE_SHIFT) & PCI_EXP_FLAGS_TYPE) |
57                  version);
58 
59     /* device capability register
60      * table 7-12:
61      * roll based error reporting bit must be set by all
62      * Functions conforming to the ECN, PCI Express Base
63      * Specification, Revision 1.1., or subsequent PCI Express Base
64      * Specification revisions.
65      */
66     pci_set_long(exp_cap + PCI_EXP_DEVCAP, PCI_EXP_DEVCAP_RBER);
67 
68     pci_set_long(exp_cap + PCI_EXP_LNKCAP,
69                  (port << PCI_EXP_LNKCAP_PN_SHIFT) |
70                  PCI_EXP_LNKCAP_ASPMS_0S |
71                  PCI_EXP_LNK_MLW_1 |
72                  PCI_EXP_LNK_LS_25);
73 
74     pci_set_word(exp_cap + PCI_EXP_LNKSTA,
75                  PCI_EXP_LNK_MLW_1 | PCI_EXP_LNK_LS_25);
76 
77     if (dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
78         pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
79                                    PCI_EXP_LNKSTA_DLLLA);
80     }
81 
82     /* We changed link status bits over time, and changing them across
83      * migrations is generally fine as hardware changes them too.
84      * Let's not bother checking.
85      */
86     pci_set_word(cmask + PCI_EXP_LNKSTA, 0);
87 }
88 
89 int pcie_cap_init(PCIDevice *dev, uint8_t offset,
90                   uint8_t type, uint8_t port,
91                   Error **errp)
92 {
93     /* PCIe cap v2 init */
94     int pos;
95     uint8_t *exp_cap;
96 
97     assert(pci_is_express(dev));
98 
99     pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
100                              PCI_EXP_VER2_SIZEOF, errp);
101     if (pos < 0) {
102         return pos;
103     }
104     dev->exp.exp_cap = pos;
105     exp_cap = dev->config + pos;
106 
107     /* Filling values common with v1 */
108     pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER2);
109 
110     /* Filling v2 specific values */
111     pci_set_long(exp_cap + PCI_EXP_DEVCAP2,
112                  PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);
113 
114     pci_set_word(dev->wmask + pos + PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_EETLPPB);
115 
116     if (dev->cap_present & QEMU_PCIE_EXTCAP_INIT) {
117         /* read-only to behave like a 'NULL' Extended Capability Header */
118         pci_set_long(dev->wmask + PCI_CONFIG_SPACE_SIZE, 0);
119     }
120 
121     return pos;
122 }
123 
124 int pcie_cap_v1_init(PCIDevice *dev, uint8_t offset, uint8_t type,
125                      uint8_t port)
126 {
127     /* PCIe cap v1 init */
128     int pos;
129     Error *local_err = NULL;
130 
131     assert(pci_is_express(dev));
132 
133     pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
134                              PCI_EXP_VER1_SIZEOF, &local_err);
135     if (pos < 0) {
136         error_report_err(local_err);
137         return pos;
138     }
139     dev->exp.exp_cap = pos;
140 
141     pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER1);
142 
143     return pos;
144 }
145 
146 static int
147 pcie_endpoint_cap_common_init(PCIDevice *dev, uint8_t offset, uint8_t cap_size)
148 {
149     uint8_t type = PCI_EXP_TYPE_ENDPOINT;
150     Error *local_err = NULL;
151     int ret;
152 
153     /*
154      * Windows guests will report Code 10, device cannot start, if
155      * a regular Endpoint type is exposed on a root complex.  These
156      * should instead be Root Complex Integrated Endpoints.
157      */
158     if (pci_bus_is_express(dev->bus) && pci_bus_is_root(dev->bus)) {
159         type = PCI_EXP_TYPE_RC_END;
160     }
161 
162     if (cap_size == PCI_EXP_VER1_SIZEOF) {
163         return pcie_cap_v1_init(dev, offset, type, 0);
164     } else {
165         ret = pcie_cap_init(dev, offset, type, 0, &local_err);
166 
167         if (ret < 0) {
168             error_report_err(local_err);
169         }
170 
171         return ret;
172     }
173 }
174 
175 int pcie_endpoint_cap_init(PCIDevice *dev, uint8_t offset)
176 {
177     return pcie_endpoint_cap_common_init(dev, offset, PCI_EXP_VER2_SIZEOF);
178 }
179 
180 int pcie_endpoint_cap_v1_init(PCIDevice *dev, uint8_t offset)
181 {
182     return pcie_endpoint_cap_common_init(dev, offset, PCI_EXP_VER1_SIZEOF);
183 }
184 
185 void pcie_cap_exit(PCIDevice *dev)
186 {
187     pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER2_SIZEOF);
188 }
189 
190 void pcie_cap_v1_exit(PCIDevice *dev)
191 {
192     pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER1_SIZEOF);
193 }
194 
195 uint8_t pcie_cap_get_type(const PCIDevice *dev)
196 {
197     uint32_t pos = dev->exp.exp_cap;
198     assert(pos > 0);
199     return (pci_get_word(dev->config + pos + PCI_EXP_FLAGS) &
200             PCI_EXP_FLAGS_TYPE) >> PCI_EXP_FLAGS_TYPE_SHIFT;
201 }
202 
203 /* MSI/MSI-X */
204 /* pci express interrupt message number */
205 /* 7.8.2 PCI Express Capabilities Register: Interrupt Message Number */
206 void pcie_cap_flags_set_vector(PCIDevice *dev, uint8_t vector)
207 {
208     uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
209     assert(vector < 32);
210     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_FLAGS, PCI_EXP_FLAGS_IRQ);
211     pci_word_test_and_set_mask(exp_cap + PCI_EXP_FLAGS,
212                                vector << PCI_EXP_FLAGS_IRQ_SHIFT);
213 }
214 
215 uint8_t pcie_cap_flags_get_vector(PCIDevice *dev)
216 {
217     return (pci_get_word(dev->config + dev->exp.exp_cap + PCI_EXP_FLAGS) &
218             PCI_EXP_FLAGS_IRQ) >> PCI_EXP_FLAGS_IRQ_SHIFT;
219 }
220 
221 void pcie_cap_deverr_init(PCIDevice *dev)
222 {
223     uint32_t pos = dev->exp.exp_cap;
224     pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP,
225                                PCI_EXP_DEVCAP_RBER);
226     pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL,
227                                PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
228                                PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
229     pci_long_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_DEVSTA,
230                                PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED |
231                                PCI_EXP_DEVSTA_FED | PCI_EXP_DEVSTA_URD);
232 }
233 
234 void pcie_cap_deverr_reset(PCIDevice *dev)
235 {
236     uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
237     pci_long_test_and_clear_mask(devctl,
238                                  PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
239                                  PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
240 }
241 
242 void pcie_cap_lnkctl_init(PCIDevice *dev)
243 {
244     uint32_t pos = dev->exp.exp_cap;
245     pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_LNKCTL,
246                                PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES);
247 }
248 
249 void pcie_cap_lnkctl_reset(PCIDevice *dev)
250 {
251     uint8_t *lnkctl = dev->config + dev->exp.exp_cap + PCI_EXP_LNKCTL;
252     pci_long_test_and_clear_mask(lnkctl,
253                                  PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES);
254 }
255 
256 static void hotplug_event_update_event_status(PCIDevice *dev)
257 {
258     uint32_t pos = dev->exp.exp_cap;
259     uint8_t *exp_cap = dev->config + pos;
260     uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
261     uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
262 
263     dev->exp.hpev_notified = (sltctl & PCI_EXP_SLTCTL_HPIE) &&
264         (sltsta & sltctl & PCI_EXP_HP_EV_SUPPORTED);
265 }
266 
267 static void hotplug_event_notify(PCIDevice *dev)
268 {
269     bool prev = dev->exp.hpev_notified;
270 
271     hotplug_event_update_event_status(dev);
272 
273     if (prev == dev->exp.hpev_notified) {
274         return;
275     }
276 
277     /* Note: the logic above does not take into account whether interrupts
278      * are masked. The result is that interrupt will be sent when it is
279      * subsequently unmasked. This appears to be legal: Section 6.7.3.4:
280      * The Port may optionally send an MSI when there are hot-plug events that
281      * occur while interrupt generation is disabled, and interrupt generation is
282      * subsequently enabled. */
283     if (msix_enabled(dev)) {
284         msix_notify(dev, pcie_cap_flags_get_vector(dev));
285     } else if (msi_enabled(dev)) {
286         msi_notify(dev, pcie_cap_flags_get_vector(dev));
287     } else {
288         pci_set_irq(dev, dev->exp.hpev_notified);
289     }
290 }
291 
292 static void hotplug_event_clear(PCIDevice *dev)
293 {
294     hotplug_event_update_event_status(dev);
295     if (!msix_enabled(dev) && !msi_enabled(dev) && !dev->exp.hpev_notified) {
296         pci_irq_deassert(dev);
297     }
298 }
299 
300 /*
301  * A PCI Express Hot-Plug Event has occurred, so update slot status register
302  * and notify OS of the event if necessary.
303  *
304  * 6.7.3 PCI Express Hot-Plug Events
305  * 6.7.3.4 Software Notification of Hot-Plug Events
306  */
307 static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
308 {
309     /* Minor optimization: if nothing changed - no event is needed. */
310     if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
311                                    PCI_EXP_SLTSTA, event)) {
312         return;
313     }
314     hotplug_event_notify(dev);
315 }
316 
317 static void pcie_cap_slot_hotplug_common(PCIDevice *hotplug_dev,
318                                          DeviceState *dev,
319                                          uint8_t **exp_cap, Error **errp)
320 {
321     *exp_cap = hotplug_dev->config + hotplug_dev->exp.exp_cap;
322     uint16_t sltsta = pci_get_word(*exp_cap + PCI_EXP_SLTSTA);
323 
324     PCIE_DEV_PRINTF(PCI_DEVICE(dev), "hotplug state: 0x%x\n", sltsta);
325     if (sltsta & PCI_EXP_SLTSTA_EIS) {
326         /* the slot is electromechanically locked.
327          * This error is propagated up to qdev and then to HMP/QMP.
328          */
329         error_setg_errno(errp, EBUSY, "slot is electromechanically locked");
330     }
331 }
332 
333 void pcie_cap_slot_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
334                               Error **errp)
335 {
336     uint8_t *exp_cap;
337     PCIDevice *pci_dev = PCI_DEVICE(dev);
338 
339     pcie_cap_slot_hotplug_common(PCI_DEVICE(hotplug_dev), dev, &exp_cap, errp);
340 
341     /* Don't send event when device is enabled during qemu machine creation:
342      * it is present on boot, no hotplug event is necessary. We do send an
343      * event when the device is disabled later. */
344     if (!dev->hotplugged) {
345         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
346                                    PCI_EXP_SLTSTA_PDS);
347         return;
348     }
349 
350     /* To enable multifunction hot-plug, we just ensure the function
351      * 0 added last. When function 0 is added, we set the sltsta and
352      * inform OS via event notification.
353      */
354     if (pci_get_function_0(pci_dev)) {
355         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
356                                    PCI_EXP_SLTSTA_PDS);
357         pcie_cap_slot_event(PCI_DEVICE(hotplug_dev),
358                             PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
359     }
360 }
361 
362 static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
363 {
364     object_unparent(OBJECT(dev));
365 }
366 
367 void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
368                                          DeviceState *dev, Error **errp)
369 {
370     uint8_t *exp_cap;
371     PCIDevice *pci_dev = PCI_DEVICE(dev);
372     PCIBus *bus = pci_dev->bus;
373 
374     pcie_cap_slot_hotplug_common(PCI_DEVICE(hotplug_dev), dev, &exp_cap, errp);
375 
376     /* In case user cancel the operation of multi-function hot-add,
377      * remove the function that is unexposed to guest individually,
378      * without interaction with guest.
379      */
380     if (pci_dev->devfn &&
381         !bus->devices[0]) {
382         pcie_unplug_device(bus, pci_dev, NULL);
383 
384         return;
385     }
386 
387     pcie_cap_slot_push_attention_button(PCI_DEVICE(hotplug_dev));
388 }
389 
390 /* pci express slot for pci express root/downstream port
391    PCI express capability slot registers */
392 void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot)
393 {
394     uint32_t pos = dev->exp.exp_cap;
395 
396     pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
397                                PCI_EXP_FLAGS_SLOT);
398 
399     pci_long_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCAP,
400                                  ~PCI_EXP_SLTCAP_PSN);
401     pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
402                                (slot << PCI_EXP_SLTCAP_PSN_SHIFT) |
403                                PCI_EXP_SLTCAP_EIP |
404                                PCI_EXP_SLTCAP_HPS |
405                                PCI_EXP_SLTCAP_HPC |
406                                PCI_EXP_SLTCAP_PIP |
407                                PCI_EXP_SLTCAP_AIP |
408                                PCI_EXP_SLTCAP_ABP);
409 
410     if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
411         pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
412                                    PCI_EXP_SLTCAP_PCP);
413         pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
414                                      PCI_EXP_SLTCTL_PCC);
415         pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
416                                    PCI_EXP_SLTCTL_PCC);
417     }
418 
419     pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
420                                  PCI_EXP_SLTCTL_PIC |
421                                  PCI_EXP_SLTCTL_AIC);
422     pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCTL,
423                                PCI_EXP_SLTCTL_PIC_OFF |
424                                PCI_EXP_SLTCTL_AIC_OFF);
425     pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
426                                PCI_EXP_SLTCTL_PIC |
427                                PCI_EXP_SLTCTL_AIC |
428                                PCI_EXP_SLTCTL_HPIE |
429                                PCI_EXP_SLTCTL_CCIE |
430                                PCI_EXP_SLTCTL_PDCE |
431                                PCI_EXP_SLTCTL_ABPE);
432     /* Although reading PCI_EXP_SLTCTL_EIC returns always 0,
433      * make the bit writable here in order to detect 1b is written.
434      * pcie_cap_slot_write_config() test-and-clear the bit, so
435      * this bit always returns 0 to the guest.
436      */
437     pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
438                                PCI_EXP_SLTCTL_EIC);
439 
440     pci_word_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_SLTSTA,
441                                PCI_EXP_HP_EV_SUPPORTED);
442 
443     dev->exp.hpev_notified = false;
444 
445     qbus_set_hotplug_handler(BUS(pci_bridge_get_sec_bus(PCI_BRIDGE(dev))),
446                              DEVICE(dev), NULL);
447 }
448 
449 void pcie_cap_slot_reset(PCIDevice *dev)
450 {
451     uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
452     uint8_t port_type = pcie_cap_get_type(dev);
453 
454     assert(port_type == PCI_EXP_TYPE_DOWNSTREAM ||
455            port_type == PCI_EXP_TYPE_ROOT_PORT);
456 
457     PCIE_DEV_PRINTF(dev, "reset\n");
458 
459     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
460                                  PCI_EXP_SLTCTL_EIC |
461                                  PCI_EXP_SLTCTL_PIC |
462                                  PCI_EXP_SLTCTL_AIC |
463                                  PCI_EXP_SLTCTL_HPIE |
464                                  PCI_EXP_SLTCTL_CCIE |
465                                  PCI_EXP_SLTCTL_PDCE |
466                                  PCI_EXP_SLTCTL_ABPE);
467     pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
468                                PCI_EXP_SLTCTL_AIC_OFF);
469 
470     if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
471         /* Downstream ports enforce device number 0. */
472         bool populated = pci_bridge_get_sec_bus(PCI_BRIDGE(dev))->devices[0];
473         uint16_t pic;
474 
475         if (populated) {
476             pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
477                                          PCI_EXP_SLTCTL_PCC);
478         } else {
479             pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
480                                        PCI_EXP_SLTCTL_PCC);
481         }
482 
483         pic = populated ? PCI_EXP_SLTCTL_PIC_ON : PCI_EXP_SLTCTL_PIC_OFF;
484         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL, pic);
485     }
486 
487     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
488                                  PCI_EXP_SLTSTA_EIS |/* on reset,
489                                                         the lock is released */
490                                  PCI_EXP_SLTSTA_CC |
491                                  PCI_EXP_SLTSTA_PDC |
492                                  PCI_EXP_SLTSTA_ABP);
493 
494     hotplug_event_update_event_status(dev);
495 }
496 
497 void pcie_cap_slot_write_config(PCIDevice *dev,
498                                 uint32_t addr, uint32_t val, int len)
499 {
500     uint32_t pos = dev->exp.exp_cap;
501     uint8_t *exp_cap = dev->config + pos;
502     uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
503 
504     if (ranges_overlap(addr, len, pos + PCI_EXP_SLTSTA, 2)) {
505         hotplug_event_clear(dev);
506     }
507 
508     if (!ranges_overlap(addr, len, pos + PCI_EXP_SLTCTL, 2)) {
509         return;
510     }
511 
512     if (pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
513                                      PCI_EXP_SLTCTL_EIC)) {
514         sltsta ^= PCI_EXP_SLTSTA_EIS; /* toggle PCI_EXP_SLTSTA_EIS bit */
515         pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
516         PCIE_DEV_PRINTF(dev, "PCI_EXP_SLTCTL_EIC: "
517                         "sltsta -> 0x%02"PRIx16"\n",
518                         sltsta);
519     }
520 
521     /*
522      * If the slot is polulated, power indicator is off and power
523      * controller is off, it is safe to detach the devices.
524      */
525     if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
526         ((val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF)) {
527         PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
528         pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
529                             pcie_unplug_device, NULL);
530 
531         pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
532                                      PCI_EXP_SLTSTA_PDS);
533         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
534                                        PCI_EXP_SLTSTA_PDC);
535     }
536 
537     hotplug_event_notify(dev);
538 
539     /*
540      * 6.7.3.2 Command Completed Events
541      *
542      * Software issues a command to a hot-plug capable Downstream Port by
543      * issuing a write transaction that targets any portion of the Port’s Slot
544      * Control register. A single write to the Slot Control register is
545      * considered to be a single command, even if the write affects more than
546      * one field in the Slot Control register. In response to this transaction,
547      * the Port must carry out the requested actions and then set the
548      * associated status field for the command completed event. */
549 
550     /* Real hardware might take a while to complete requested command because
551      * physical movement would be involved like locking the electromechanical
552      * lock.  However in our case, command is completed instantaneously above,
553      * so send a command completion event right now.
554      */
555     pcie_cap_slot_event(dev, PCI_EXP_HP_EV_CCI);
556 }
557 
558 int pcie_cap_slot_post_load(void *opaque, int version_id)
559 {
560     PCIDevice *dev = opaque;
561     hotplug_event_update_event_status(dev);
562     return 0;
563 }
564 
565 void pcie_cap_slot_push_attention_button(PCIDevice *dev)
566 {
567     pcie_cap_slot_event(dev, PCI_EXP_HP_EV_ABP);
568 }
569 
570 /* root control/capabilities/status. PME isn't emulated for now */
571 void pcie_cap_root_init(PCIDevice *dev)
572 {
573     pci_set_word(dev->wmask + dev->exp.exp_cap + PCI_EXP_RTCTL,
574                  PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
575                  PCI_EXP_RTCTL_SEFEE);
576 }
577 
578 void pcie_cap_root_reset(PCIDevice *dev)
579 {
580     pci_set_word(dev->config + dev->exp.exp_cap + PCI_EXP_RTCTL, 0);
581 }
582 
583 /* function level reset(FLR) */
584 void pcie_cap_flr_init(PCIDevice *dev)
585 {
586     pci_long_test_and_set_mask(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCAP,
587                                PCI_EXP_DEVCAP_FLR);
588 
589     /* Although reading BCR_FLR returns always 0,
590      * the bit is made writable here in order to detect the 1b is written
591      * pcie_cap_flr_write_config() test-and-clear the bit, so
592      * this bit always returns 0 to the guest.
593      */
594     pci_word_test_and_set_mask(dev->wmask + dev->exp.exp_cap + PCI_EXP_DEVCTL,
595                                PCI_EXP_DEVCTL_BCR_FLR);
596 }
597 
598 void pcie_cap_flr_write_config(PCIDevice *dev,
599                                uint32_t addr, uint32_t val, int len)
600 {
601     uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
602     if (pci_get_word(devctl) & PCI_EXP_DEVCTL_BCR_FLR) {
603         /* Clear PCI_EXP_DEVCTL_BCR_FLR after invoking the reset handler
604            so the handler can detect FLR by looking at this bit. */
605         pci_device_reset(dev);
606         pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR);
607     }
608 }
609 
610 /* Alternative Routing-ID Interpretation (ARI)
611  * forwarding support for root and downstream ports
612  */
613 void pcie_cap_arifwd_init(PCIDevice *dev)
614 {
615     uint32_t pos = dev->exp.exp_cap;
616     pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP2,
617                                PCI_EXP_DEVCAP2_ARI);
618     pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL2,
619                                PCI_EXP_DEVCTL2_ARI);
620 }
621 
622 void pcie_cap_arifwd_reset(PCIDevice *dev)
623 {
624     uint8_t *devctl2 = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2;
625     pci_long_test_and_clear_mask(devctl2, PCI_EXP_DEVCTL2_ARI);
626 }
627 
628 bool pcie_cap_is_arifwd_enabled(const PCIDevice *dev)
629 {
630     if (!pci_is_express(dev)) {
631         return false;
632     }
633     if (!dev->exp.exp_cap) {
634         return false;
635     }
636 
637     return pci_get_long(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2) &
638         PCI_EXP_DEVCTL2_ARI;
639 }
640 
641 /**************************************************************************
642  * pci express extended capability list management functions
643  * uint16_t ext_cap_id (16 bit)
644  * uint8_t cap_ver (4 bit)
645  * uint16_t cap_offset (12 bit)
646  * uint16_t ext_cap_size
647  */
648 
649 /* Passing a cap_id value > 0xffff will return 0 and put end of list in prev */
650 static uint16_t pcie_find_capability_list(PCIDevice *dev, uint32_t cap_id,
651                                           uint16_t *prev_p)
652 {
653     uint16_t prev = 0;
654     uint16_t next;
655     uint32_t header = pci_get_long(dev->config + PCI_CONFIG_SPACE_SIZE);
656 
657     if (!header) {
658         /* no extended capability */
659         next = 0;
660         goto out;
661     }
662     for (next = PCI_CONFIG_SPACE_SIZE; next;
663          prev = next, next = PCI_EXT_CAP_NEXT(header)) {
664 
665         assert(next >= PCI_CONFIG_SPACE_SIZE);
666         assert(next <= PCIE_CONFIG_SPACE_SIZE - 8);
667 
668         header = pci_get_long(dev->config + next);
669         if (PCI_EXT_CAP_ID(header) == cap_id) {
670             break;
671         }
672     }
673 
674 out:
675     if (prev_p) {
676         *prev_p = prev;
677     }
678     return next;
679 }
680 
681 uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id)
682 {
683     return pcie_find_capability_list(dev, cap_id, NULL);
684 }
685 
686 static void pcie_ext_cap_set_next(PCIDevice *dev, uint16_t pos, uint16_t next)
687 {
688     uint32_t header = pci_get_long(dev->config + pos);
689     assert(!(next & (PCI_EXT_CAP_ALIGN - 1)));
690     header = (header & ~PCI_EXT_CAP_NEXT_MASK) |
691         ((next << PCI_EXT_CAP_NEXT_SHIFT) & PCI_EXT_CAP_NEXT_MASK);
692     pci_set_long(dev->config + pos, header);
693 }
694 
695 /*
696  * Caller must supply valid (offset, size) such that the range wouldn't
697  * overlap with other capability or other registers.
698  * This function doesn't check it.
699  */
700 void pcie_add_capability(PCIDevice *dev,
701                          uint16_t cap_id, uint8_t cap_ver,
702                          uint16_t offset, uint16_t size)
703 {
704     assert(offset >= PCI_CONFIG_SPACE_SIZE);
705     assert(offset < offset + size);
706     assert(offset + size <= PCIE_CONFIG_SPACE_SIZE);
707     assert(size >= 8);
708     assert(pci_is_express(dev));
709 
710     if (offset != PCI_CONFIG_SPACE_SIZE) {
711         uint16_t prev;
712 
713         /*
714          * 0xffffffff is not a valid cap id (it's a 16 bit field). use
715          * internally to find the last capability in the linked list.
716          */
717         pcie_find_capability_list(dev, 0xffffffff, &prev);
718         assert(prev >= PCI_CONFIG_SPACE_SIZE);
719         pcie_ext_cap_set_next(dev, prev, offset);
720     }
721     pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, 0));
722 
723     /* Make capability read-only by default */
724     memset(dev->wmask + offset, 0, size);
725     memset(dev->w1cmask + offset, 0, size);
726     /* Check capability by default */
727     memset(dev->cmask + offset, 0xFF, size);
728 }
729 
730 /**************************************************************************
731  * pci express extended capability helper functions
732  */
733 
734 /* ARI */
735 void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn)
736 {
737     pcie_add_capability(dev, PCI_EXT_CAP_ID_ARI, PCI_ARI_VER,
738                         offset, PCI_ARI_SIZEOF);
739     pci_set_long(dev->config + offset + PCI_ARI_CAP, (nextfn & 0xff) << 8);
740 }
741 
742 void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num)
743 {
744     static const int pci_dsn_ver = 1;
745     static const int pci_dsn_cap = 4;
746 
747     pcie_add_capability(dev, PCI_EXT_CAP_ID_DSN, pci_dsn_ver, offset,
748                         PCI_EXT_CAP_DSN_SIZEOF);
749     pci_set_quad(dev->config + offset + pci_dsn_cap, ser_num);
750 }
751 
752 void pcie_ats_init(PCIDevice *dev, uint16_t offset)
753 {
754     pcie_add_capability(dev, PCI_EXT_CAP_ID_ATS, 0x1,
755                         offset, PCI_EXT_CAP_ATS_SIZEOF);
756 
757     dev->exp.ats_cap = offset;
758 
759     /* Invalidate Queue Depth 0, Page Aligned Request 0 */
760     pci_set_word(dev->config + offset + PCI_ATS_CAP, 0);
761     /* STU 0, Disabled by default */
762     pci_set_word(dev->config + offset + PCI_ATS_CTRL, 0);
763 
764     pci_set_word(dev->wmask + dev->exp.ats_cap + PCI_ATS_CTRL, 0x800f);
765 }
766