xref: /openbmc/qemu/hw/pci/pcie.c (revision 39337f12)
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 "hw/pci/pci_bridge.h"
24 #include "hw/pci/pcie.h"
25 #include "hw/pci/msix.h"
26 #include "hw/pci/msi.h"
27 #include "hw/pci/pci_bus.h"
28 #include "hw/pci/pcie_regs.h"
29 #include "hw/pci/pcie_port.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                  QEMU_PCI_EXP_LNKCAP_MLW(QEMU_PCI_EXP_LNK_X1) |
72                  QEMU_PCI_EXP_LNKCAP_MLS(QEMU_PCI_EXP_LNK_2_5GT));
73 
74     pci_set_word(exp_cap + PCI_EXP_LNKSTA,
75                  QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1) |
76                  QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT));
77 
78     if (dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
79         pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
80                                    PCI_EXP_LNKSTA_DLLLA);
81     }
82 
83     /* We changed link status bits over time, and changing them across
84      * migrations is generally fine as hardware changes them too.
85      * Let's not bother checking.
86      */
87     pci_set_word(cmask + PCI_EXP_LNKSTA, 0);
88 }
89 
90 static void pcie_cap_fill_slot_lnk(PCIDevice *dev)
91 {
92     PCIESlot *s = (PCIESlot *)object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT);
93     uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
94 
95     /* Skip anything that isn't a PCIESlot */
96     if (!s) {
97         return;
98     }
99 
100     /* Clear and fill LNKCAP from what was configured above */
101     pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP,
102                                  PCI_EXP_LNKCAP_MLW | PCI_EXP_LNKCAP_SLS);
103     pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
104                                QEMU_PCI_EXP_LNKCAP_MLW(s->width) |
105                                QEMU_PCI_EXP_LNKCAP_MLS(s->speed));
106 
107     /*
108      * Link bandwidth notification is required for all root ports and
109      * downstream ports supporting links wider than x1 or multiple link
110      * speeds.
111      */
112     if (s->width > QEMU_PCI_EXP_LNK_X1 ||
113         s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
114         pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
115                                    PCI_EXP_LNKCAP_LBNC);
116     }
117 
118     if (s->speed > QEMU_PCI_EXP_LNK_2_5GT) {
119         /*
120          * Hot-plug capable downstream ports and downstream ports supporting
121          * link speeds greater than 5GT/s must hardwire PCI_EXP_LNKCAP_DLLLARC
122          * to 1b.  PCI_EXP_LNKCAP_DLLLARC implies PCI_EXP_LNKSTA_DLLLA, which
123          * we also hardwire to 1b here.  2.5GT/s hot-plug slots should also
124          * technically implement this, but it's not done here for compatibility.
125          */
126         pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP,
127                                    PCI_EXP_LNKCAP_DLLLARC);
128         pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
129                                    PCI_EXP_LNKSTA_DLLLA);
130 
131         /*
132          * Target Link Speed defaults to the highest link speed supported by
133          * the component.  2.5GT/s devices are permitted to hardwire to zero.
134          */
135         pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKCTL2,
136                                      PCI_EXP_LNKCTL2_TLS);
137         pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKCTL2,
138                                    QEMU_PCI_EXP_LNKCAP_MLS(s->speed) &
139                                    PCI_EXP_LNKCTL2_TLS);
140     }
141 
142     /*
143      * 2.5 & 5.0GT/s can be fully described by LNKCAP, but 8.0GT/s is
144      * actually a reference to the highest bit supported in this register.
145      * We assume the device supports all link speeds.
146      */
147     if (s->speed > QEMU_PCI_EXP_LNK_5GT) {
148         pci_long_test_and_clear_mask(exp_cap + PCI_EXP_LNKCAP2, ~0U);
149         pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
150                                    PCI_EXP_LNKCAP2_SLS_2_5GB |
151                                    PCI_EXP_LNKCAP2_SLS_5_0GB |
152                                    PCI_EXP_LNKCAP2_SLS_8_0GB);
153         if (s->speed > QEMU_PCI_EXP_LNK_8GT) {
154             pci_long_test_and_set_mask(exp_cap + PCI_EXP_LNKCAP2,
155                                        PCI_EXP_LNKCAP2_SLS_16_0GB);
156         }
157     }
158 }
159 
160 int pcie_cap_init(PCIDevice *dev, uint8_t offset,
161                   uint8_t type, uint8_t port,
162                   Error **errp)
163 {
164     /* PCIe cap v2 init */
165     int pos;
166     uint8_t *exp_cap;
167 
168     assert(pci_is_express(dev));
169 
170     pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
171                              PCI_EXP_VER2_SIZEOF, errp);
172     if (pos < 0) {
173         return pos;
174     }
175     dev->exp.exp_cap = pos;
176     exp_cap = dev->config + pos;
177 
178     /* Filling values common with v1 */
179     pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER2);
180 
181     /* Fill link speed and width options */
182     pcie_cap_fill_slot_lnk(dev);
183 
184     /* Filling v2 specific values */
185     pci_set_long(exp_cap + PCI_EXP_DEVCAP2,
186                  PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);
187 
188     pci_set_word(dev->wmask + pos + PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_EETLPPB);
189 
190     if (dev->cap_present & QEMU_PCIE_EXTCAP_INIT) {
191         /* read-only to behave like a 'NULL' Extended Capability Header */
192         pci_set_long(dev->wmask + PCI_CONFIG_SPACE_SIZE, 0);
193     }
194 
195     return pos;
196 }
197 
198 int pcie_cap_v1_init(PCIDevice *dev, uint8_t offset, uint8_t type,
199                      uint8_t port)
200 {
201     /* PCIe cap v1 init */
202     int pos;
203     Error *local_err = NULL;
204 
205     assert(pci_is_express(dev));
206 
207     pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
208                              PCI_EXP_VER1_SIZEOF, &local_err);
209     if (pos < 0) {
210         error_report_err(local_err);
211         return pos;
212     }
213     dev->exp.exp_cap = pos;
214 
215     pcie_cap_v1_fill(dev, port, type, PCI_EXP_FLAGS_VER1);
216 
217     return pos;
218 }
219 
220 static int
221 pcie_endpoint_cap_common_init(PCIDevice *dev, uint8_t offset, uint8_t cap_size)
222 {
223     uint8_t type = PCI_EXP_TYPE_ENDPOINT;
224     Error *local_err = NULL;
225     int ret;
226 
227     /*
228      * Windows guests will report Code 10, device cannot start, if
229      * a regular Endpoint type is exposed on a root complex.  These
230      * should instead be Root Complex Integrated Endpoints.
231      */
232     if (pci_bus_is_express(pci_get_bus(dev))
233         && pci_bus_is_root(pci_get_bus(dev))) {
234         type = PCI_EXP_TYPE_RC_END;
235     }
236 
237     if (cap_size == PCI_EXP_VER1_SIZEOF) {
238         return pcie_cap_v1_init(dev, offset, type, 0);
239     } else {
240         ret = pcie_cap_init(dev, offset, type, 0, &local_err);
241 
242         if (ret < 0) {
243             error_report_err(local_err);
244         }
245 
246         return ret;
247     }
248 }
249 
250 int pcie_endpoint_cap_init(PCIDevice *dev, uint8_t offset)
251 {
252     return pcie_endpoint_cap_common_init(dev, offset, PCI_EXP_VER2_SIZEOF);
253 }
254 
255 int pcie_endpoint_cap_v1_init(PCIDevice *dev, uint8_t offset)
256 {
257     return pcie_endpoint_cap_common_init(dev, offset, PCI_EXP_VER1_SIZEOF);
258 }
259 
260 void pcie_cap_exit(PCIDevice *dev)
261 {
262     pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER2_SIZEOF);
263 }
264 
265 void pcie_cap_v1_exit(PCIDevice *dev)
266 {
267     pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER1_SIZEOF);
268 }
269 
270 uint8_t pcie_cap_get_type(const PCIDevice *dev)
271 {
272     uint32_t pos = dev->exp.exp_cap;
273     assert(pos > 0);
274     return (pci_get_word(dev->config + pos + PCI_EXP_FLAGS) &
275             PCI_EXP_FLAGS_TYPE) >> PCI_EXP_FLAGS_TYPE_SHIFT;
276 }
277 
278 /* MSI/MSI-X */
279 /* pci express interrupt message number */
280 /* 7.8.2 PCI Express Capabilities Register: Interrupt Message Number */
281 void pcie_cap_flags_set_vector(PCIDevice *dev, uint8_t vector)
282 {
283     uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
284     assert(vector < 32);
285     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_FLAGS, PCI_EXP_FLAGS_IRQ);
286     pci_word_test_and_set_mask(exp_cap + PCI_EXP_FLAGS,
287                                vector << PCI_EXP_FLAGS_IRQ_SHIFT);
288 }
289 
290 uint8_t pcie_cap_flags_get_vector(PCIDevice *dev)
291 {
292     return (pci_get_word(dev->config + dev->exp.exp_cap + PCI_EXP_FLAGS) &
293             PCI_EXP_FLAGS_IRQ) >> PCI_EXP_FLAGS_IRQ_SHIFT;
294 }
295 
296 void pcie_cap_deverr_init(PCIDevice *dev)
297 {
298     uint32_t pos = dev->exp.exp_cap;
299     pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP,
300                                PCI_EXP_DEVCAP_RBER);
301     pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL,
302                                PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
303                                PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
304     pci_long_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_DEVSTA,
305                                PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED |
306                                PCI_EXP_DEVSTA_FED | PCI_EXP_DEVSTA_URD);
307 }
308 
309 void pcie_cap_deverr_reset(PCIDevice *dev)
310 {
311     uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
312     pci_long_test_and_clear_mask(devctl,
313                                  PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
314                                  PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
315 }
316 
317 void pcie_cap_lnkctl_init(PCIDevice *dev)
318 {
319     uint32_t pos = dev->exp.exp_cap;
320     pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_LNKCTL,
321                                PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES);
322 }
323 
324 void pcie_cap_lnkctl_reset(PCIDevice *dev)
325 {
326     uint8_t *lnkctl = dev->config + dev->exp.exp_cap + PCI_EXP_LNKCTL;
327     pci_long_test_and_clear_mask(lnkctl,
328                                  PCI_EXP_LNKCTL_CCC | PCI_EXP_LNKCTL_ES);
329 }
330 
331 static void hotplug_event_update_event_status(PCIDevice *dev)
332 {
333     uint32_t pos = dev->exp.exp_cap;
334     uint8_t *exp_cap = dev->config + pos;
335     uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
336     uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
337 
338     dev->exp.hpev_notified = (sltctl & PCI_EXP_SLTCTL_HPIE) &&
339         (sltsta & sltctl & PCI_EXP_HP_EV_SUPPORTED);
340 }
341 
342 static void hotplug_event_notify(PCIDevice *dev)
343 {
344     bool prev = dev->exp.hpev_notified;
345 
346     hotplug_event_update_event_status(dev);
347 
348     if (prev == dev->exp.hpev_notified) {
349         return;
350     }
351 
352     /* Note: the logic above does not take into account whether interrupts
353      * are masked. The result is that interrupt will be sent when it is
354      * subsequently unmasked. This appears to be legal: Section 6.7.3.4:
355      * The Port may optionally send an MSI when there are hot-plug events that
356      * occur while interrupt generation is disabled, and interrupt generation is
357      * subsequently enabled. */
358     if (msix_enabled(dev)) {
359         msix_notify(dev, pcie_cap_flags_get_vector(dev));
360     } else if (msi_enabled(dev)) {
361         msi_notify(dev, pcie_cap_flags_get_vector(dev));
362     } else {
363         pci_set_irq(dev, dev->exp.hpev_notified);
364     }
365 }
366 
367 static void hotplug_event_clear(PCIDevice *dev)
368 {
369     hotplug_event_update_event_status(dev);
370     if (!msix_enabled(dev) && !msi_enabled(dev) && !dev->exp.hpev_notified) {
371         pci_irq_deassert(dev);
372     }
373 }
374 
375 /*
376  * A PCI Express Hot-Plug Event has occurred, so update slot status register
377  * and notify OS of the event if necessary.
378  *
379  * 6.7.3 PCI Express Hot-Plug Events
380  * 6.7.3.4 Software Notification of Hot-Plug Events
381  */
382 static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
383 {
384     /* Minor optimization: if nothing changed - no event is needed. */
385     if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
386                                    PCI_EXP_SLTSTA, event) == event) {
387         return;
388     }
389     hotplug_event_notify(dev);
390 }
391 
392 static void pcie_cap_slot_plug_common(PCIDevice *hotplug_dev, DeviceState *dev,
393                                       Error **errp)
394 {
395     uint8_t *exp_cap = hotplug_dev->config + hotplug_dev->exp.exp_cap;
396     uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
397 
398     PCIE_DEV_PRINTF(PCI_DEVICE(dev), "hotplug state: 0x%x\n", sltsta);
399     if (sltsta & PCI_EXP_SLTSTA_EIS) {
400         /* the slot is electromechanically locked.
401          * This error is propagated up to qdev and then to HMP/QMP.
402          */
403         error_setg_errno(errp, EBUSY, "slot is electromechanically locked");
404     }
405 }
406 
407 void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
408                                Error **errp)
409 {
410     PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
411     uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
412     uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);
413 
414     /* Check if hot-plug is disabled on the slot */
415     if (dev->hotplugged && (sltcap & PCI_EXP_SLTCAP_HPC) == 0) {
416         error_setg(errp, "Hot-plug failed: unsupported by the port device '%s'",
417                          DEVICE(hotplug_pdev)->id);
418         return;
419     }
420 
421     pcie_cap_slot_plug_common(PCI_DEVICE(hotplug_dev), dev, errp);
422 }
423 
424 void pcie_cap_slot_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
425                            Error **errp)
426 {
427     PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
428     uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
429     PCIDevice *pci_dev = PCI_DEVICE(dev);
430 
431     /* Don't send event when device is enabled during qemu machine creation:
432      * it is present on boot, no hotplug event is necessary. We do send an
433      * event when the device is disabled later. */
434     if (!dev->hotplugged) {
435         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
436                                    PCI_EXP_SLTSTA_PDS);
437         if (pci_dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
438             pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
439                                        PCI_EXP_LNKSTA_DLLLA);
440         }
441         return;
442     }
443 
444     /* To enable multifunction hot-plug, we just ensure the function
445      * 0 added last. When function 0 is added, we set the sltsta and
446      * inform OS via event notification.
447      */
448     if (pci_get_function_0(pci_dev)) {
449         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
450                                    PCI_EXP_SLTSTA_PDS);
451         if (pci_dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
452             pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA,
453                                        PCI_EXP_LNKSTA_DLLLA);
454         }
455         pcie_cap_slot_event(hotplug_pdev,
456                             PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
457     }
458 }
459 
460 void pcie_cap_slot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
461                              Error **errp)
462 {
463     qdev_unrealize(dev);
464 }
465 
466 static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
467 {
468     HotplugHandler *hotplug_ctrl = qdev_get_hotplug_handler(DEVICE(dev));
469 
470     if (dev->partially_hotplugged) {
471         dev->qdev.pending_deleted_event = false;
472         return;
473     }
474     hotplug_handler_unplug(hotplug_ctrl, DEVICE(dev), &error_abort);
475     object_unparent(OBJECT(dev));
476 }
477 
478 void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
479                                      DeviceState *dev, Error **errp)
480 {
481     Error *local_err = NULL;
482     PCIDevice *pci_dev = PCI_DEVICE(dev);
483     PCIBus *bus = pci_get_bus(pci_dev);
484     PCIDevice *hotplug_pdev = PCI_DEVICE(hotplug_dev);
485     uint8_t *exp_cap = hotplug_pdev->config + hotplug_pdev->exp.exp_cap;
486     uint32_t sltcap = pci_get_word(exp_cap + PCI_EXP_SLTCAP);
487 
488     /* Check if hot-unplug is disabled on the slot */
489     if ((sltcap & PCI_EXP_SLTCAP_HPC) == 0) {
490         error_setg(errp, "Hot-unplug failed: "
491                          "unsupported by the port device '%s'",
492                          DEVICE(hotplug_pdev)->id);
493         return;
494     }
495 
496     pcie_cap_slot_plug_common(hotplug_pdev, dev, &local_err);
497     if (local_err) {
498         error_propagate(errp, local_err);
499         return;
500     }
501 
502     dev->pending_deleted_event = true;
503 
504     /* In case user cancel the operation of multi-function hot-add,
505      * remove the function that is unexposed to guest individually,
506      * without interaction with guest.
507      */
508     if (pci_dev->devfn &&
509         !bus->devices[0]) {
510         pcie_unplug_device(bus, pci_dev, NULL);
511 
512         return;
513     }
514 
515     pcie_cap_slot_push_attention_button(hotplug_pdev);
516 }
517 
518 /* pci express slot for pci express root/downstream port
519    PCI express capability slot registers */
520 void pcie_cap_slot_init(PCIDevice *dev, PCIESlot *s)
521 {
522     uint32_t pos = dev->exp.exp_cap;
523 
524     pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
525                                PCI_EXP_FLAGS_SLOT);
526 
527     pci_long_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCAP,
528                                  ~PCI_EXP_SLTCAP_PSN);
529     pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
530                                (s->slot << PCI_EXP_SLTCAP_PSN_SHIFT) |
531                                PCI_EXP_SLTCAP_EIP |
532                                PCI_EXP_SLTCAP_PIP |
533                                PCI_EXP_SLTCAP_AIP |
534                                PCI_EXP_SLTCAP_ABP);
535     if (s->hotplug) {
536         pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
537                                    PCI_EXP_SLTCAP_HPS |
538                                    PCI_EXP_SLTCAP_HPC);
539     }
540 
541     if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
542         pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
543                                    PCI_EXP_SLTCAP_PCP);
544         pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
545                                      PCI_EXP_SLTCTL_PCC);
546         pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
547                                    PCI_EXP_SLTCTL_PCC);
548     }
549 
550     pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
551                                  PCI_EXP_SLTCTL_PIC |
552                                  PCI_EXP_SLTCTL_AIC);
553     pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCTL,
554                                PCI_EXP_SLTCTL_PIC_OFF |
555                                PCI_EXP_SLTCTL_AIC_OFF);
556     pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
557                                PCI_EXP_SLTCTL_PIC |
558                                PCI_EXP_SLTCTL_AIC |
559                                PCI_EXP_SLTCTL_HPIE |
560                                PCI_EXP_SLTCTL_CCIE |
561                                PCI_EXP_SLTCTL_PDCE |
562                                PCI_EXP_SLTCTL_ABPE);
563     /* Although reading PCI_EXP_SLTCTL_EIC returns always 0,
564      * make the bit writable here in order to detect 1b is written.
565      * pcie_cap_slot_write_config() test-and-clear the bit, so
566      * this bit always returns 0 to the guest.
567      */
568     pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
569                                PCI_EXP_SLTCTL_EIC);
570 
571     pci_word_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_SLTSTA,
572                                PCI_EXP_HP_EV_SUPPORTED);
573 
574     dev->exp.hpev_notified = false;
575 
576     qbus_set_hotplug_handler(BUS(pci_bridge_get_sec_bus(PCI_BRIDGE(dev))),
577                              OBJECT(dev), NULL);
578 }
579 
580 void pcie_cap_slot_reset(PCIDevice *dev)
581 {
582     uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
583     uint8_t port_type = pcie_cap_get_type(dev);
584 
585     assert(port_type == PCI_EXP_TYPE_DOWNSTREAM ||
586            port_type == PCI_EXP_TYPE_ROOT_PORT);
587 
588     PCIE_DEV_PRINTF(dev, "reset\n");
589 
590     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
591                                  PCI_EXP_SLTCTL_EIC |
592                                  PCI_EXP_SLTCTL_PIC |
593                                  PCI_EXP_SLTCTL_AIC |
594                                  PCI_EXP_SLTCTL_HPIE |
595                                  PCI_EXP_SLTCTL_CCIE |
596                                  PCI_EXP_SLTCTL_PDCE |
597                                  PCI_EXP_SLTCTL_ABPE);
598     pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
599                                PCI_EXP_SLTCTL_AIC_OFF);
600 
601     if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
602         /* Downstream ports enforce device number 0. */
603         bool populated = pci_bridge_get_sec_bus(PCI_BRIDGE(dev))->devices[0];
604         uint16_t pic;
605 
606         if (populated) {
607             pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
608                                          PCI_EXP_SLTCTL_PCC);
609         } else {
610             pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
611                                        PCI_EXP_SLTCTL_PCC);
612         }
613 
614         pic = populated ? PCI_EXP_SLTCTL_PIC_ON : PCI_EXP_SLTCTL_PIC_OFF;
615         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL, pic);
616     }
617 
618     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
619                                  PCI_EXP_SLTSTA_EIS |/* on reset,
620                                                         the lock is released */
621                                  PCI_EXP_SLTSTA_CC |
622                                  PCI_EXP_SLTSTA_PDC |
623                                  PCI_EXP_SLTSTA_ABP);
624 
625     hotplug_event_update_event_status(dev);
626 }
627 
628 void pcie_cap_slot_get(PCIDevice *dev, uint16_t *slt_ctl, uint16_t *slt_sta)
629 {
630     uint32_t pos = dev->exp.exp_cap;
631     uint8_t *exp_cap = dev->config + pos;
632     *slt_ctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
633     *slt_sta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
634 }
635 
636 void pcie_cap_slot_write_config(PCIDevice *dev,
637                                 uint16_t old_slt_ctl, uint16_t old_slt_sta,
638                                 uint32_t addr, uint32_t val, int len)
639 {
640     uint32_t pos = dev->exp.exp_cap;
641     uint8_t *exp_cap = dev->config + pos;
642     uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
643 
644     if (ranges_overlap(addr, len, pos + PCI_EXP_SLTSTA, 2)) {
645         /*
646          * Guests tend to clears all bits during init.
647          * If they clear bits that weren't set this is racy and will lose events:
648          * not a big problem for manual button presses, but a problem for us.
649          * As a work-around, detect this and revert status to what it was
650          * before the write.
651          *
652          * Note: in theory this can be detected as a duplicate button press
653          * which cancels the previous press. Does not seem to happen in
654          * practice as guests seem to only have this bug during init.
655          */
656 #define PCIE_SLOT_EVENTS (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD | \
657                           PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC | \
658                           PCI_EXP_SLTSTA_CC)
659 
660         if (val & ~old_slt_sta & PCIE_SLOT_EVENTS) {
661             sltsta = (sltsta & ~PCIE_SLOT_EVENTS) | (old_slt_sta & PCIE_SLOT_EVENTS);
662             pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
663         }
664         hotplug_event_clear(dev);
665     }
666 
667     if (!ranges_overlap(addr, len, pos + PCI_EXP_SLTCTL, 2)) {
668         return;
669     }
670 
671     if (pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
672                                      PCI_EXP_SLTCTL_EIC)) {
673         sltsta ^= PCI_EXP_SLTSTA_EIS; /* toggle PCI_EXP_SLTSTA_EIS bit */
674         pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
675         PCIE_DEV_PRINTF(dev, "PCI_EXP_SLTCTL_EIC: "
676                         "sltsta -> 0x%02"PRIx16"\n",
677                         sltsta);
678     }
679 
680     /*
681      * If the slot is populated, power indicator is off and power
682      * controller is off, it is safe to detach the devices.
683      *
684      * Note: don't detach if condition was already true:
685      * this is a work around for guests that overwrite
686      * control of powered off slots before powering them on.
687      */
688     if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
689         (val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF &&
690         (!(old_slt_ctl & PCI_EXP_SLTCTL_PCC) ||
691         (old_slt_ctl & PCI_EXP_SLTCTL_PIC_OFF) != PCI_EXP_SLTCTL_PIC_OFF)) {
692         PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
693         pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
694                             pcie_unplug_device, NULL);
695 
696         pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
697                                      PCI_EXP_SLTSTA_PDS);
698         if (dev->cap_present & QEMU_PCIE_LNKSTA_DLLLA) {
699             pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
700                                          PCI_EXP_LNKSTA_DLLLA);
701         }
702         pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
703                                        PCI_EXP_SLTSTA_PDC);
704     }
705 
706     hotplug_event_notify(dev);
707 
708     /*
709      * 6.7.3.2 Command Completed Events
710      *
711      * Software issues a command to a hot-plug capable Downstream Port by
712      * issuing a write transaction that targets any portion of the Port’s Slot
713      * Control register. A single write to the Slot Control register is
714      * considered to be a single command, even if the write affects more than
715      * one field in the Slot Control register. In response to this transaction,
716      * the Port must carry out the requested actions and then set the
717      * associated status field for the command completed event. */
718 
719     /* Real hardware might take a while to complete requested command because
720      * physical movement would be involved like locking the electromechanical
721      * lock.  However in our case, command is completed instantaneously above,
722      * so send a command completion event right now.
723      */
724     pcie_cap_slot_event(dev, PCI_EXP_HP_EV_CCI);
725 }
726 
727 int pcie_cap_slot_post_load(void *opaque, int version_id)
728 {
729     PCIDevice *dev = opaque;
730     hotplug_event_update_event_status(dev);
731     return 0;
732 }
733 
734 void pcie_cap_slot_push_attention_button(PCIDevice *dev)
735 {
736     pcie_cap_slot_event(dev, PCI_EXP_HP_EV_ABP);
737 }
738 
739 /* root control/capabilities/status. PME isn't emulated for now */
740 void pcie_cap_root_init(PCIDevice *dev)
741 {
742     pci_set_word(dev->wmask + dev->exp.exp_cap + PCI_EXP_RTCTL,
743                  PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
744                  PCI_EXP_RTCTL_SEFEE);
745 }
746 
747 void pcie_cap_root_reset(PCIDevice *dev)
748 {
749     pci_set_word(dev->config + dev->exp.exp_cap + PCI_EXP_RTCTL, 0);
750 }
751 
752 /* function level reset(FLR) */
753 void pcie_cap_flr_init(PCIDevice *dev)
754 {
755     pci_long_test_and_set_mask(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCAP,
756                                PCI_EXP_DEVCAP_FLR);
757 
758     /* Although reading BCR_FLR returns always 0,
759      * the bit is made writable here in order to detect the 1b is written
760      * pcie_cap_flr_write_config() test-and-clear the bit, so
761      * this bit always returns 0 to the guest.
762      */
763     pci_word_test_and_set_mask(dev->wmask + dev->exp.exp_cap + PCI_EXP_DEVCTL,
764                                PCI_EXP_DEVCTL_BCR_FLR);
765 }
766 
767 void pcie_cap_flr_write_config(PCIDevice *dev,
768                                uint32_t addr, uint32_t val, int len)
769 {
770     uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
771     if (pci_get_word(devctl) & PCI_EXP_DEVCTL_BCR_FLR) {
772         /* Clear PCI_EXP_DEVCTL_BCR_FLR after invoking the reset handler
773            so the handler can detect FLR by looking at this bit. */
774         pci_device_reset(dev);
775         pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR);
776     }
777 }
778 
779 /* Alternative Routing-ID Interpretation (ARI)
780  * forwarding support for root and downstream ports
781  */
782 void pcie_cap_arifwd_init(PCIDevice *dev)
783 {
784     uint32_t pos = dev->exp.exp_cap;
785     pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP2,
786                                PCI_EXP_DEVCAP2_ARI);
787     pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL2,
788                                PCI_EXP_DEVCTL2_ARI);
789 }
790 
791 void pcie_cap_arifwd_reset(PCIDevice *dev)
792 {
793     uint8_t *devctl2 = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2;
794     pci_long_test_and_clear_mask(devctl2, PCI_EXP_DEVCTL2_ARI);
795 }
796 
797 bool pcie_cap_is_arifwd_enabled(const PCIDevice *dev)
798 {
799     if (!pci_is_express(dev)) {
800         return false;
801     }
802     if (!dev->exp.exp_cap) {
803         return false;
804     }
805 
806     return pci_get_long(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2) &
807         PCI_EXP_DEVCTL2_ARI;
808 }
809 
810 /**************************************************************************
811  * pci express extended capability list management functions
812  * uint16_t ext_cap_id (16 bit)
813  * uint8_t cap_ver (4 bit)
814  * uint16_t cap_offset (12 bit)
815  * uint16_t ext_cap_size
816  */
817 
818 /* Passing a cap_id value > 0xffff will return 0 and put end of list in prev */
819 static uint16_t pcie_find_capability_list(PCIDevice *dev, uint32_t cap_id,
820                                           uint16_t *prev_p)
821 {
822     uint16_t prev = 0;
823     uint16_t next;
824     uint32_t header = pci_get_long(dev->config + PCI_CONFIG_SPACE_SIZE);
825 
826     if (!header) {
827         /* no extended capability */
828         next = 0;
829         goto out;
830     }
831     for (next = PCI_CONFIG_SPACE_SIZE; next;
832          prev = next, next = PCI_EXT_CAP_NEXT(header)) {
833 
834         assert(next >= PCI_CONFIG_SPACE_SIZE);
835         assert(next <= PCIE_CONFIG_SPACE_SIZE - 8);
836 
837         header = pci_get_long(dev->config + next);
838         if (PCI_EXT_CAP_ID(header) == cap_id) {
839             break;
840         }
841     }
842 
843 out:
844     if (prev_p) {
845         *prev_p = prev;
846     }
847     return next;
848 }
849 
850 uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id)
851 {
852     return pcie_find_capability_list(dev, cap_id, NULL);
853 }
854 
855 static void pcie_ext_cap_set_next(PCIDevice *dev, uint16_t pos, uint16_t next)
856 {
857     uint32_t header = pci_get_long(dev->config + pos);
858     assert(!(next & (PCI_EXT_CAP_ALIGN - 1)));
859     header = (header & ~PCI_EXT_CAP_NEXT_MASK) |
860         ((next << PCI_EXT_CAP_NEXT_SHIFT) & PCI_EXT_CAP_NEXT_MASK);
861     pci_set_long(dev->config + pos, header);
862 }
863 
864 /*
865  * Caller must supply valid (offset, size) such that the range wouldn't
866  * overlap with other capability or other registers.
867  * This function doesn't check it.
868  */
869 void pcie_add_capability(PCIDevice *dev,
870                          uint16_t cap_id, uint8_t cap_ver,
871                          uint16_t offset, uint16_t size)
872 {
873     assert(offset >= PCI_CONFIG_SPACE_SIZE);
874     assert(offset < offset + size);
875     assert(offset + size <= PCIE_CONFIG_SPACE_SIZE);
876     assert(size >= 8);
877     assert(pci_is_express(dev));
878 
879     if (offset != PCI_CONFIG_SPACE_SIZE) {
880         uint16_t prev;
881 
882         /*
883          * 0xffffffff is not a valid cap id (it's a 16 bit field). use
884          * internally to find the last capability in the linked list.
885          */
886         pcie_find_capability_list(dev, 0xffffffff, &prev);
887         assert(prev >= PCI_CONFIG_SPACE_SIZE);
888         pcie_ext_cap_set_next(dev, prev, offset);
889     }
890     pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, 0));
891 
892     /* Make capability read-only by default */
893     memset(dev->wmask + offset, 0, size);
894     memset(dev->w1cmask + offset, 0, size);
895     /* Check capability by default */
896     memset(dev->cmask + offset, 0xFF, size);
897 }
898 
899 /*
900  * Sync the PCIe Link Status negotiated speed and width of a bridge with the
901  * downstream device.  If downstream device is not present, re-write with the
902  * Link Capability fields.  If downstream device reports invalid width or
903  * speed, replace with minimum values (LnkSta fields are RsvdZ on VFs but such
904  * values interfere with PCIe native hotplug detecting new devices).  Limit
905  * width and speed to bridge capabilities for compatibility.  Use config_read
906  * to access the downstream device since it could be an assigned device with
907  * volatile link information.
908  */
909 void pcie_sync_bridge_lnk(PCIDevice *bridge_dev)
910 {
911     PCIBridge *br = PCI_BRIDGE(bridge_dev);
912     PCIBus *bus = pci_bridge_get_sec_bus(br);
913     PCIDevice *target = bus->devices[0];
914     uint8_t *exp_cap = bridge_dev->config + bridge_dev->exp.exp_cap;
915     uint16_t lnksta, lnkcap = pci_get_word(exp_cap + PCI_EXP_LNKCAP);
916 
917     if (!target || !target->exp.exp_cap) {
918         lnksta = lnkcap;
919     } else {
920         lnksta = target->config_read(target,
921                                      target->exp.exp_cap + PCI_EXP_LNKSTA,
922                                      sizeof(lnksta));
923 
924         if ((lnksta & PCI_EXP_LNKSTA_NLW) > (lnkcap & PCI_EXP_LNKCAP_MLW)) {
925             lnksta &= ~PCI_EXP_LNKSTA_NLW;
926             lnksta |= lnkcap & PCI_EXP_LNKCAP_MLW;
927         } else if (!(lnksta & PCI_EXP_LNKSTA_NLW)) {
928             lnksta |= QEMU_PCI_EXP_LNKSTA_NLW(QEMU_PCI_EXP_LNK_X1);
929         }
930 
931         if ((lnksta & PCI_EXP_LNKSTA_CLS) > (lnkcap & PCI_EXP_LNKCAP_SLS)) {
932             lnksta &= ~PCI_EXP_LNKSTA_CLS;
933             lnksta |= lnkcap & PCI_EXP_LNKCAP_SLS;
934         } else if (!(lnksta & PCI_EXP_LNKSTA_CLS)) {
935             lnksta |= QEMU_PCI_EXP_LNKSTA_CLS(QEMU_PCI_EXP_LNK_2_5GT);
936         }
937     }
938 
939     pci_word_test_and_clear_mask(exp_cap + PCI_EXP_LNKSTA,
940                                  PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW);
941     pci_word_test_and_set_mask(exp_cap + PCI_EXP_LNKSTA, lnksta &
942                                (PCI_EXP_LNKSTA_CLS | PCI_EXP_LNKSTA_NLW));
943 }
944 
945 /**************************************************************************
946  * pci express extended capability helper functions
947  */
948 
949 /* ARI */
950 void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn)
951 {
952     pcie_add_capability(dev, PCI_EXT_CAP_ID_ARI, PCI_ARI_VER,
953                         offset, PCI_ARI_SIZEOF);
954     pci_set_long(dev->config + offset + PCI_ARI_CAP, (nextfn & 0xff) << 8);
955 }
956 
957 void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num)
958 {
959     static const int pci_dsn_ver = 1;
960     static const int pci_dsn_cap = 4;
961 
962     pcie_add_capability(dev, PCI_EXT_CAP_ID_DSN, pci_dsn_ver, offset,
963                         PCI_EXT_CAP_DSN_SIZEOF);
964     pci_set_quad(dev->config + offset + pci_dsn_cap, ser_num);
965 }
966 
967 void pcie_ats_init(PCIDevice *dev, uint16_t offset)
968 {
969     pcie_add_capability(dev, PCI_EXT_CAP_ID_ATS, 0x1,
970                         offset, PCI_EXT_CAP_ATS_SIZEOF);
971 
972     dev->exp.ats_cap = offset;
973 
974     /* Invalidate Queue Depth 0, Page Aligned Request 0 */
975     pci_set_word(dev->config + offset + PCI_ATS_CAP, 0);
976     /* STU 0, Disabled by default */
977     pci_set_word(dev->config + offset + PCI_ATS_CTRL, 0);
978 
979     pci_set_word(dev->wmask + dev->exp.ats_cap + PCI_ATS_CTRL, 0x800f);
980 }
981 
982 /* ACS (Access Control Services) */
983 void pcie_acs_init(PCIDevice *dev, uint16_t offset)
984 {
985     bool is_downstream = pci_is_express_downstream_port(dev);
986     uint16_t cap_bits = 0;
987 
988     /* For endpoints, only multifunction devs may have an ACS capability: */
989     assert(is_downstream ||
990            (dev->cap_present & QEMU_PCI_CAP_MULTIFUNCTION) ||
991            PCI_FUNC(dev->devfn));
992 
993     pcie_add_capability(dev, PCI_EXT_CAP_ID_ACS, PCI_ACS_VER, offset,
994                         PCI_ACS_SIZEOF);
995     dev->exp.acs_cap = offset;
996 
997     if (is_downstream) {
998         /*
999          * Downstream ports must implement SV, TB, RR, CR, UF, and DT (with
1000          * caveats on the latter four that we ignore for simplicity).
1001          * Endpoints may also implement a subset of ACS capabilities,
1002          * but these are optional if the endpoint does not support
1003          * peer-to-peer between functions and thus omitted here.
1004          */
1005         cap_bits = PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
1006             PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT;
1007     }
1008 
1009     pci_set_word(dev->config + offset + PCI_ACS_CAP, cap_bits);
1010     pci_set_word(dev->wmask + offset + PCI_ACS_CTRL, cap_bits);
1011 }
1012 
1013 void pcie_acs_reset(PCIDevice *dev)
1014 {
1015     if (dev->exp.acs_cap) {
1016         pci_set_word(dev->config + dev->exp.acs_cap + PCI_ACS_CTRL, 0);
1017     }
1018 }
1019