xref: /openbmc/qemu/hw/pci/pcie.c (revision 43b48cfc3e8ff745a10a6b78a55519d5cf7ec5e8)
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 "qemu-common.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 "qemu/range.h"
30  
31  //#define DEBUG_PCIE
32  #ifdef DEBUG_PCIE
33  # define PCIE_DPRINTF(fmt, ...)                                         \
34      fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)
35  #else
36  # define PCIE_DPRINTF(fmt, ...) do {} while (0)
37  #endif
38  #define PCIE_DEV_PRINTF(dev, fmt, ...)                                  \
39      PCIE_DPRINTF("%s:%x "fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)
40  
41  
42  /***************************************************************************
43   * pci express capability helper functions
44   */
45  int pcie_cap_init(PCIDevice *dev, uint8_t offset, uint8_t type, uint8_t port)
46  {
47      int pos;
48      uint8_t *exp_cap;
49  
50      assert(pci_is_express(dev));
51  
52      pos = pci_add_capability(dev, PCI_CAP_ID_EXP, offset,
53                                   PCI_EXP_VER2_SIZEOF);
54      if (pos < 0) {
55          return pos;
56      }
57      dev->exp.exp_cap = pos;
58      exp_cap = dev->config + pos;
59  
60      /* capability register
61         interrupt message number defaults to 0 */
62      pci_set_word(exp_cap + PCI_EXP_FLAGS,
63                   ((type << PCI_EXP_FLAGS_TYPE_SHIFT) & PCI_EXP_FLAGS_TYPE) |
64                   PCI_EXP_FLAGS_VER2);
65  
66      /* device capability register
67       * table 7-12:
68       * roll based error reporting bit must be set by all
69       * Functions conforming to the ECN, PCI Express Base
70       * Specification, Revision 1.1., or subsequent PCI Express Base
71       * Specification revisions.
72       */
73      pci_set_long(exp_cap + PCI_EXP_DEVCAP, PCI_EXP_DEVCAP_RBER);
74  
75      pci_set_long(exp_cap + PCI_EXP_LNKCAP,
76                   (port << PCI_EXP_LNKCAP_PN_SHIFT) |
77                   PCI_EXP_LNKCAP_ASPMS_0S |
78                   PCI_EXP_LNK_MLW_1 |
79                   PCI_EXP_LNK_LS_25);
80  
81      pci_set_word(exp_cap + PCI_EXP_LNKSTA,
82                   PCI_EXP_LNK_MLW_1 | PCI_EXP_LNK_LS_25 |PCI_EXP_LNKSTA_DLLLA);
83  
84      pci_set_long(exp_cap + PCI_EXP_DEVCAP2,
85                   PCI_EXP_DEVCAP2_EFF | PCI_EXP_DEVCAP2_EETLPP);
86  
87      pci_set_word(dev->wmask + pos + PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_EETLPPB);
88      return pos;
89  }
90  
91  int pcie_endpoint_cap_init(PCIDevice *dev, uint8_t offset)
92  {
93      uint8_t type = PCI_EXP_TYPE_ENDPOINT;
94  
95      /*
96       * Windows guests will report Code 10, device cannot start, if
97       * a regular Endpoint type is exposed on a root complex.  These
98       * should instead be Root Complex Integrated Endpoints.
99       */
100      if (pci_bus_is_express(dev->bus) && pci_bus_is_root(dev->bus)) {
101          type = PCI_EXP_TYPE_RC_END;
102      }
103  
104      return pcie_cap_init(dev, offset, type, 0);
105  }
106  
107  void pcie_cap_exit(PCIDevice *dev)
108  {
109      pci_del_capability(dev, PCI_CAP_ID_EXP, PCI_EXP_VER2_SIZEOF);
110  }
111  
112  uint8_t pcie_cap_get_type(const PCIDevice *dev)
113  {
114      uint32_t pos = dev->exp.exp_cap;
115      assert(pos > 0);
116      return (pci_get_word(dev->config + pos + PCI_EXP_FLAGS) &
117              PCI_EXP_FLAGS_TYPE) >> PCI_EXP_FLAGS_TYPE_SHIFT;
118  }
119  
120  /* MSI/MSI-X */
121  /* pci express interrupt message number */
122  /* 7.8.2 PCI Express Capabilities Register: Interrupt Message Number */
123  void pcie_cap_flags_set_vector(PCIDevice *dev, uint8_t vector)
124  {
125      uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
126      assert(vector < 32);
127      pci_word_test_and_clear_mask(exp_cap + PCI_EXP_FLAGS, PCI_EXP_FLAGS_IRQ);
128      pci_word_test_and_set_mask(exp_cap + PCI_EXP_FLAGS,
129                                 vector << PCI_EXP_FLAGS_IRQ_SHIFT);
130  }
131  
132  uint8_t pcie_cap_flags_get_vector(PCIDevice *dev)
133  {
134      return (pci_get_word(dev->config + dev->exp.exp_cap + PCI_EXP_FLAGS) &
135              PCI_EXP_FLAGS_IRQ) >> PCI_EXP_FLAGS_IRQ_SHIFT;
136  }
137  
138  void pcie_cap_deverr_init(PCIDevice *dev)
139  {
140      uint32_t pos = dev->exp.exp_cap;
141      pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP,
142                                 PCI_EXP_DEVCAP_RBER);
143      pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL,
144                                 PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
145                                 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
146      pci_long_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_DEVSTA,
147                                 PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED |
148                                 PCI_EXP_DEVSTA_FED | PCI_EXP_DEVSTA_URD);
149  }
150  
151  void pcie_cap_deverr_reset(PCIDevice *dev)
152  {
153      uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
154      pci_long_test_and_clear_mask(devctl,
155                                   PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE |
156                                   PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE);
157  }
158  
159  static void hotplug_event_update_event_status(PCIDevice *dev)
160  {
161      uint32_t pos = dev->exp.exp_cap;
162      uint8_t *exp_cap = dev->config + pos;
163      uint16_t sltctl = pci_get_word(exp_cap + PCI_EXP_SLTCTL);
164      uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
165  
166      dev->exp.hpev_notified = (sltctl & PCI_EXP_SLTCTL_HPIE) &&
167          (sltsta & sltctl & PCI_EXP_HP_EV_SUPPORTED);
168  }
169  
170  static void hotplug_event_notify(PCIDevice *dev)
171  {
172      bool prev = dev->exp.hpev_notified;
173  
174      hotplug_event_update_event_status(dev);
175  
176      if (prev == dev->exp.hpev_notified) {
177          return;
178      }
179  
180      /* Note: the logic above does not take into account whether interrupts
181       * are masked. The result is that interrupt will be sent when it is
182       * subsequently unmasked. This appears to be legal: Section 6.7.3.4:
183       * The Port may optionally send an MSI when there are hot-plug events that
184       * occur while interrupt generation is disabled, and interrupt generation is
185       * subsequently enabled. */
186      if (msix_enabled(dev)) {
187          msix_notify(dev, pcie_cap_flags_get_vector(dev));
188      } else if (msi_enabled(dev)) {
189          msi_notify(dev, pcie_cap_flags_get_vector(dev));
190      } else {
191          pci_set_irq(dev, dev->exp.hpev_notified);
192      }
193  }
194  
195  static void hotplug_event_clear(PCIDevice *dev)
196  {
197      hotplug_event_update_event_status(dev);
198      if (!msix_enabled(dev) && !msi_enabled(dev) && !dev->exp.hpev_notified) {
199          pci_irq_deassert(dev);
200      }
201  }
202  
203  /*
204   * A PCI Express Hot-Plug Event has occurred, so update slot status register
205   * and notify OS of the event if necessary.
206   *
207   * 6.7.3 PCI Express Hot-Plug Events
208   * 6.7.3.4 Software Notification of Hot-Plug Events
209   */
210  static void pcie_cap_slot_event(PCIDevice *dev, PCIExpressHotPlugEvent event)
211  {
212      /* Minor optimization: if nothing changed - no event is needed. */
213      if (pci_word_test_and_set_mask(dev->config + dev->exp.exp_cap +
214                                     PCI_EXP_SLTSTA, event)) {
215          return;
216      }
217      hotplug_event_notify(dev);
218  }
219  
220  static void pcie_cap_slot_hotplug_common(PCIDevice *hotplug_dev,
221                                           DeviceState *dev,
222                                           uint8_t **exp_cap, Error **errp)
223  {
224      *exp_cap = hotplug_dev->config + hotplug_dev->exp.exp_cap;
225      uint16_t sltsta = pci_get_word(*exp_cap + PCI_EXP_SLTSTA);
226  
227      PCIE_DEV_PRINTF(PCI_DEVICE(dev), "hotplug state: 0x%x\n", sltsta);
228      if (sltsta & PCI_EXP_SLTSTA_EIS) {
229          /* the slot is electromechanically locked.
230           * This error is propagated up to qdev and then to HMP/QMP.
231           */
232          error_setg_errno(errp, EBUSY, "slot is electromechanically locked");
233      }
234  }
235  
236  void pcie_cap_slot_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
237                                Error **errp)
238  {
239      uint8_t *exp_cap;
240      PCIDevice *pci_dev = PCI_DEVICE(dev);
241  
242      pcie_cap_slot_hotplug_common(PCI_DEVICE(hotplug_dev), dev, &exp_cap, errp);
243  
244      /* Don't send event when device is enabled during qemu machine creation:
245       * it is present on boot, no hotplug event is necessary. We do send an
246       * event when the device is disabled later. */
247      if (!dev->hotplugged) {
248          pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
249                                     PCI_EXP_SLTSTA_PDS);
250          return;
251      }
252  
253      /* To enable multifunction hot-plug, we just ensure the function
254       * 0 added last. When function 0 is added, we set the sltsta and
255       * inform OS via event notification.
256       */
257      if (pci_get_function_0(pci_dev)) {
258          pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
259                                     PCI_EXP_SLTSTA_PDS);
260          pcie_cap_slot_event(PCI_DEVICE(hotplug_dev),
261                              PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
262      }
263  }
264  
265  static void pcie_unplug_device(PCIBus *bus, PCIDevice *dev, void *opaque)
266  {
267      object_unparent(OBJECT(dev));
268  }
269  
270  void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
271                                           DeviceState *dev, Error **errp)
272  {
273      uint8_t *exp_cap;
274      PCIDevice *pci_dev = PCI_DEVICE(dev);
275      PCIBus *bus = pci_dev->bus;
276  
277      pcie_cap_slot_hotplug_common(PCI_DEVICE(hotplug_dev), dev, &exp_cap, errp);
278  
279      /* In case user cancel the operation of multi-function hot-add,
280       * remove the function that is unexposed to guest individually,
281       * without interaction with guest.
282       */
283      if (pci_dev->devfn &&
284          !bus->devices[0]) {
285          pcie_unplug_device(bus, pci_dev, NULL);
286  
287          return;
288      }
289  
290      pcie_cap_slot_push_attention_button(PCI_DEVICE(hotplug_dev));
291  }
292  
293  /* pci express slot for pci express root/downstream port
294     PCI express capability slot registers */
295  void pcie_cap_slot_init(PCIDevice *dev, uint16_t slot)
296  {
297      uint32_t pos = dev->exp.exp_cap;
298  
299      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_FLAGS,
300                                 PCI_EXP_FLAGS_SLOT);
301  
302      pci_long_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCAP,
303                                   ~PCI_EXP_SLTCAP_PSN);
304      pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
305                                 (slot << PCI_EXP_SLTCAP_PSN_SHIFT) |
306                                 PCI_EXP_SLTCAP_EIP |
307                                 PCI_EXP_SLTCAP_HPS |
308                                 PCI_EXP_SLTCAP_HPC |
309                                 PCI_EXP_SLTCAP_PIP |
310                                 PCI_EXP_SLTCAP_AIP |
311                                 PCI_EXP_SLTCAP_ABP);
312  
313      if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
314          pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCAP,
315                                     PCI_EXP_SLTCAP_PCP);
316          pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
317                                       PCI_EXP_SLTCTL_PCC);
318          pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
319                                     PCI_EXP_SLTCTL_PCC);
320      }
321  
322      pci_word_test_and_clear_mask(dev->config + pos + PCI_EXP_SLTCTL,
323                                   PCI_EXP_SLTCTL_PIC |
324                                   PCI_EXP_SLTCTL_AIC);
325      pci_word_test_and_set_mask(dev->config + pos + PCI_EXP_SLTCTL,
326                                 PCI_EXP_SLTCTL_PIC_OFF |
327                                 PCI_EXP_SLTCTL_AIC_OFF);
328      pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
329                                 PCI_EXP_SLTCTL_PIC |
330                                 PCI_EXP_SLTCTL_AIC |
331                                 PCI_EXP_SLTCTL_HPIE |
332                                 PCI_EXP_SLTCTL_CCIE |
333                                 PCI_EXP_SLTCTL_PDCE |
334                                 PCI_EXP_SLTCTL_ABPE);
335      /* Although reading PCI_EXP_SLTCTL_EIC returns always 0,
336       * make the bit writable here in order to detect 1b is written.
337       * pcie_cap_slot_write_config() test-and-clear the bit, so
338       * this bit always returns 0 to the guest.
339       */
340      pci_word_test_and_set_mask(dev->wmask + pos + PCI_EXP_SLTCTL,
341                                 PCI_EXP_SLTCTL_EIC);
342  
343      pci_word_test_and_set_mask(dev->w1cmask + pos + PCI_EXP_SLTSTA,
344                                 PCI_EXP_HP_EV_SUPPORTED);
345  
346      dev->exp.hpev_notified = false;
347  
348      qbus_set_hotplug_handler(BUS(pci_bridge_get_sec_bus(PCI_BRIDGE(dev))),
349                               DEVICE(dev), NULL);
350  }
351  
352  void pcie_cap_slot_reset(PCIDevice *dev)
353  {
354      uint8_t *exp_cap = dev->config + dev->exp.exp_cap;
355      uint8_t port_type = pcie_cap_get_type(dev);
356  
357      assert(port_type == PCI_EXP_TYPE_DOWNSTREAM ||
358             port_type == PCI_EXP_TYPE_ROOT_PORT);
359  
360      PCIE_DEV_PRINTF(dev, "reset\n");
361  
362      pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
363                                   PCI_EXP_SLTCTL_EIC |
364                                   PCI_EXP_SLTCTL_PIC |
365                                   PCI_EXP_SLTCTL_AIC |
366                                   PCI_EXP_SLTCTL_HPIE |
367                                   PCI_EXP_SLTCTL_CCIE |
368                                   PCI_EXP_SLTCTL_PDCE |
369                                   PCI_EXP_SLTCTL_ABPE);
370      pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
371                                 PCI_EXP_SLTCTL_AIC_OFF);
372  
373      if (dev->cap_present & QEMU_PCIE_SLTCAP_PCP) {
374          /* Downstream ports enforce device number 0. */
375          bool populated = pci_bridge_get_sec_bus(PCI_BRIDGE(dev))->devices[0];
376          uint16_t pic;
377  
378          if (populated) {
379              pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
380                                           PCI_EXP_SLTCTL_PCC);
381          } else {
382              pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL,
383                                         PCI_EXP_SLTCTL_PCC);
384          }
385  
386          pic = populated ? PCI_EXP_SLTCTL_PIC_ON : PCI_EXP_SLTCTL_PIC_OFF;
387          pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTCTL, pic);
388      }
389  
390      pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
391                                   PCI_EXP_SLTSTA_EIS |/* on reset,
392                                                          the lock is released */
393                                   PCI_EXP_SLTSTA_CC |
394                                   PCI_EXP_SLTSTA_PDC |
395                                   PCI_EXP_SLTSTA_ABP);
396  
397      hotplug_event_update_event_status(dev);
398  }
399  
400  void pcie_cap_slot_write_config(PCIDevice *dev,
401                                  uint32_t addr, uint32_t val, int len)
402  {
403      uint32_t pos = dev->exp.exp_cap;
404      uint8_t *exp_cap = dev->config + pos;
405      uint16_t sltsta = pci_get_word(exp_cap + PCI_EXP_SLTSTA);
406  
407      if (ranges_overlap(addr, len, pos + PCI_EXP_SLTSTA, 2)) {
408          hotplug_event_clear(dev);
409      }
410  
411      if (!ranges_overlap(addr, len, pos + PCI_EXP_SLTCTL, 2)) {
412          return;
413      }
414  
415      if (pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTCTL,
416                                       PCI_EXP_SLTCTL_EIC)) {
417          sltsta ^= PCI_EXP_SLTSTA_EIS; /* toggle PCI_EXP_SLTSTA_EIS bit */
418          pci_set_word(exp_cap + PCI_EXP_SLTSTA, sltsta);
419          PCIE_DEV_PRINTF(dev, "PCI_EXP_SLTCTL_EIC: "
420                          "sltsta -> 0x%02"PRIx16"\n",
421                          sltsta);
422      }
423  
424      /*
425       * If the slot is polulated, power indicator is off and power
426       * controller is off, it is safe to detach the devices.
427       */
428      if ((sltsta & PCI_EXP_SLTSTA_PDS) && (val & PCI_EXP_SLTCTL_PCC) &&
429          ((val & PCI_EXP_SLTCTL_PIC_OFF) == PCI_EXP_SLTCTL_PIC_OFF)) {
430          PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(dev));
431          pci_for_each_device(sec_bus, pci_bus_num(sec_bus),
432                              pcie_unplug_device, NULL);
433  
434          pci_word_test_and_clear_mask(exp_cap + PCI_EXP_SLTSTA,
435                                       PCI_EXP_SLTSTA_PDS);
436          pci_word_test_and_set_mask(exp_cap + PCI_EXP_SLTSTA,
437                                         PCI_EXP_SLTSTA_PDC);
438      }
439  
440      hotplug_event_notify(dev);
441  
442      /*
443       * 6.7.3.2 Command Completed Events
444       *
445       * Software issues a command to a hot-plug capable Downstream Port by
446       * issuing a write transaction that targets any portion of the Port’s Slot
447       * Control register. A single write to the Slot Control register is
448       * considered to be a single command, even if the write affects more than
449       * one field in the Slot Control register. In response to this transaction,
450       * the Port must carry out the requested actions and then set the
451       * associated status field for the command completed event. */
452  
453      /* Real hardware might take a while to complete requested command because
454       * physical movement would be involved like locking the electromechanical
455       * lock.  However in our case, command is completed instantaneously above,
456       * so send a command completion event right now.
457       */
458      pcie_cap_slot_event(dev, PCI_EXP_HP_EV_CCI);
459  }
460  
461  int pcie_cap_slot_post_load(void *opaque, int version_id)
462  {
463      PCIDevice *dev = opaque;
464      hotplug_event_update_event_status(dev);
465      return 0;
466  }
467  
468  void pcie_cap_slot_push_attention_button(PCIDevice *dev)
469  {
470      pcie_cap_slot_event(dev, PCI_EXP_HP_EV_ABP);
471  }
472  
473  /* root control/capabilities/status. PME isn't emulated for now */
474  void pcie_cap_root_init(PCIDevice *dev)
475  {
476      pci_set_word(dev->wmask + dev->exp.exp_cap + PCI_EXP_RTCTL,
477                   PCI_EXP_RTCTL_SECEE | PCI_EXP_RTCTL_SENFEE |
478                   PCI_EXP_RTCTL_SEFEE);
479  }
480  
481  void pcie_cap_root_reset(PCIDevice *dev)
482  {
483      pci_set_word(dev->config + dev->exp.exp_cap + PCI_EXP_RTCTL, 0);
484  }
485  
486  /* function level reset(FLR) */
487  void pcie_cap_flr_init(PCIDevice *dev)
488  {
489      pci_long_test_and_set_mask(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCAP,
490                                 PCI_EXP_DEVCAP_FLR);
491  
492      /* Although reading BCR_FLR returns always 0,
493       * the bit is made writable here in order to detect the 1b is written
494       * pcie_cap_flr_write_config() test-and-clear the bit, so
495       * this bit always returns 0 to the guest.
496       */
497      pci_word_test_and_set_mask(dev->wmask + dev->exp.exp_cap + PCI_EXP_DEVCTL,
498                                 PCI_EXP_DEVCTL_BCR_FLR);
499  }
500  
501  void pcie_cap_flr_write_config(PCIDevice *dev,
502                                 uint32_t addr, uint32_t val, int len)
503  {
504      uint8_t *devctl = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL;
505      if (pci_get_word(devctl) & PCI_EXP_DEVCTL_BCR_FLR) {
506          /* Clear PCI_EXP_DEVCTL_BCR_FLR after invoking the reset handler
507             so the handler can detect FLR by looking at this bit. */
508          pci_device_reset(dev);
509          pci_word_test_and_clear_mask(devctl, PCI_EXP_DEVCTL_BCR_FLR);
510      }
511  }
512  
513  /* Alternative Routing-ID Interpretation (ARI)
514   * forwarding support for root and downstream ports
515   */
516  void pcie_cap_arifwd_init(PCIDevice *dev)
517  {
518      uint32_t pos = dev->exp.exp_cap;
519      pci_long_test_and_set_mask(dev->config + pos + PCI_EXP_DEVCAP2,
520                                 PCI_EXP_DEVCAP2_ARI);
521      pci_long_test_and_set_mask(dev->wmask + pos + PCI_EXP_DEVCTL2,
522                                 PCI_EXP_DEVCTL2_ARI);
523  }
524  
525  void pcie_cap_arifwd_reset(PCIDevice *dev)
526  {
527      uint8_t *devctl2 = dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2;
528      pci_long_test_and_clear_mask(devctl2, PCI_EXP_DEVCTL2_ARI);
529  }
530  
531  bool pcie_cap_is_arifwd_enabled(const PCIDevice *dev)
532  {
533      if (!pci_is_express(dev)) {
534          return false;
535      }
536      if (!dev->exp.exp_cap) {
537          return false;
538      }
539  
540      return pci_get_long(dev->config + dev->exp.exp_cap + PCI_EXP_DEVCTL2) &
541          PCI_EXP_DEVCTL2_ARI;
542  }
543  
544  /**************************************************************************
545   * pci express extended capability list management functions
546   * uint16_t ext_cap_id (16 bit)
547   * uint8_t cap_ver (4 bit)
548   * uint16_t cap_offset (12 bit)
549   * uint16_t ext_cap_size
550   */
551  
552  static uint16_t pcie_find_capability_list(PCIDevice *dev, uint16_t cap_id,
553                                            uint16_t *prev_p)
554  {
555      uint16_t prev = 0;
556      uint16_t next;
557      uint32_t header = pci_get_long(dev->config + PCI_CONFIG_SPACE_SIZE);
558  
559      if (!header) {
560          /* no extended capability */
561          next = 0;
562          goto out;
563      }
564      for (next = PCI_CONFIG_SPACE_SIZE; next;
565           prev = next, next = PCI_EXT_CAP_NEXT(header)) {
566  
567          assert(next >= PCI_CONFIG_SPACE_SIZE);
568          assert(next <= PCIE_CONFIG_SPACE_SIZE - 8);
569  
570          header = pci_get_long(dev->config + next);
571          if (PCI_EXT_CAP_ID(header) == cap_id) {
572              break;
573          }
574      }
575  
576  out:
577      if (prev_p) {
578          *prev_p = prev;
579      }
580      return next;
581  }
582  
583  uint16_t pcie_find_capability(PCIDevice *dev, uint16_t cap_id)
584  {
585      return pcie_find_capability_list(dev, cap_id, NULL);
586  }
587  
588  static void pcie_ext_cap_set_next(PCIDevice *dev, uint16_t pos, uint16_t next)
589  {
590      uint32_t header = pci_get_long(dev->config + pos);
591      assert(!(next & (PCI_EXT_CAP_ALIGN - 1)));
592      header = (header & ~PCI_EXT_CAP_NEXT_MASK) |
593          ((next << PCI_EXT_CAP_NEXT_SHIFT) & PCI_EXT_CAP_NEXT_MASK);
594      pci_set_long(dev->config + pos, header);
595  }
596  
597  /*
598   * caller must supply valid (offset, size) * such that the range shouldn't
599   * overlap with other capability or other registers.
600   * This function doesn't check it.
601   */
602  void pcie_add_capability(PCIDevice *dev,
603                           uint16_t cap_id, uint8_t cap_ver,
604                           uint16_t offset, uint16_t size)
605  {
606      uint32_t header;
607      uint16_t next;
608  
609      assert(offset >= PCI_CONFIG_SPACE_SIZE);
610      assert(offset < offset + size);
611      assert(offset + size < PCIE_CONFIG_SPACE_SIZE);
612      assert(size >= 8);
613      assert(pci_is_express(dev));
614  
615      if (offset == PCI_CONFIG_SPACE_SIZE) {
616          header = pci_get_long(dev->config + offset);
617          next = PCI_EXT_CAP_NEXT(header);
618      } else {
619          uint16_t prev;
620  
621          /* 0 is reserved cap id. use internally to find the last capability
622             in the linked list */
623          next = pcie_find_capability_list(dev, 0, &prev);
624  
625          assert(prev >= PCI_CONFIG_SPACE_SIZE);
626          assert(next == 0);
627          pcie_ext_cap_set_next(dev, prev, offset);
628      }
629      pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, next));
630  
631      /* Make capability read-only by default */
632      memset(dev->wmask + offset, 0, size);
633      memset(dev->w1cmask + offset, 0, size);
634      /* Check capability by default */
635      memset(dev->cmask + offset, 0xFF, size);
636  }
637  
638  /**************************************************************************
639   * pci express extended capability helper functions
640   */
641  
642  /* ARI */
643  void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn)
644  {
645      pcie_add_capability(dev, PCI_EXT_CAP_ID_ARI, PCI_ARI_VER,
646                          offset, PCI_ARI_SIZEOF);
647      pci_set_long(dev->config + offset + PCI_ARI_CAP, (nextfn & 0xff) << 8);
648  }
649