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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * PCI Express PCI Hot Plug Driver
4 *
5 * Copyright (C) 1995,2001 Compaq Computer Corporation
6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
7 * Copyright (C) 2001 IBM Corp.
8 * Copyright (C) 2003-2004 Intel Corporation
9 *
10 * All rights reserved.
11 *
12 * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com>
13 */
14
15#define dev_fmt(fmt) "pciehp: " fmt
16
17#include <linux/bitfield.h>
18#include <linux/dmi.h>
19#include <linux/kernel.h>
20#include <linux/types.h>
21#include <linux/jiffies.h>
22#include <linux/kthread.h>
23#include <linux/pci.h>
24#include <linux/pm_runtime.h>
25#include <linux/interrupt.h>
26#include <linux/slab.h>
27
28#include "../pci.h"
29#include "pciehp.h"
30
31static const struct dmi_system_id inband_presence_disabled_dmi_table[] = {
32 /*
33 * Match all Dell systems, as some Dell systems have inband
34 * presence disabled on NVMe slots (but don't support the bit to
35 * report it). Setting inband presence disabled should have no
36 * negative effect, except on broken hotplug slots that never
37 * assert presence detect--and those will still work, they will
38 * just have a bit of extra delay before being probed.
39 */
40 {
41 .ident = "Dell System",
42 .matches = {
43 DMI_MATCH(DMI_OEM_STRING, "Dell System"),
44 },
45 },
46 {}
47};
48
49static inline struct pci_dev *ctrl_dev(struct controller *ctrl)
50{
51 return ctrl->pcie->port;
52}
53
54static irqreturn_t pciehp_isr(int irq, void *dev_id);
55static irqreturn_t pciehp_ist(int irq, void *dev_id);
56static int pciehp_poll(void *data);
57
58static inline int pciehp_request_irq(struct controller *ctrl)
59{
60 int retval, irq = ctrl->pcie->irq;
61
62 if (pciehp_poll_mode) {
63 ctrl->poll_thread = kthread_run(&pciehp_poll, ctrl,
64 "pciehp_poll-%s",
65 slot_name(ctrl));
66 return PTR_ERR_OR_ZERO(ctrl->poll_thread);
67 }
68
69 /* Installs the interrupt handler */
70 retval = request_threaded_irq(irq, pciehp_isr, pciehp_ist,
71 IRQF_SHARED, "pciehp", ctrl);
72 if (retval)
73 ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
74 irq);
75 return retval;
76}
77
78static inline void pciehp_free_irq(struct controller *ctrl)
79{
80 if (pciehp_poll_mode)
81 kthread_stop(ctrl->poll_thread);
82 else
83 free_irq(ctrl->pcie->irq, ctrl);
84}
85
86static int pcie_poll_cmd(struct controller *ctrl, int timeout)
87{
88 struct pci_dev *pdev = ctrl_dev(ctrl);
89 u16 slot_status;
90
91 do {
92 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
93 if (PCI_POSSIBLE_ERROR(slot_status)) {
94 ctrl_info(ctrl, "%s: no response from device\n",
95 __func__);
96 return 0;
97 }
98
99 if (slot_status & PCI_EXP_SLTSTA_CC) {
100 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
101 PCI_EXP_SLTSTA_CC);
102 ctrl->cmd_busy = 0;
103 smp_mb();
104 return 1;
105 }
106 msleep(10);
107 timeout -= 10;
108 } while (timeout >= 0);
109 return 0; /* timeout */
110}
111
112static void pcie_wait_cmd(struct controller *ctrl)
113{
114 unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
115 unsigned long duration = msecs_to_jiffies(msecs);
116 unsigned long cmd_timeout = ctrl->cmd_started + duration;
117 unsigned long now, timeout;
118 int rc;
119
120 /*
121 * If the controller does not generate notifications for command
122 * completions, we never need to wait between writes.
123 */
124 if (NO_CMD_CMPL(ctrl))
125 return;
126
127 if (!ctrl->cmd_busy)
128 return;
129
130 /*
131 * Even if the command has already timed out, we want to call
132 * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
133 */
134 now = jiffies;
135 if (time_before_eq(cmd_timeout, now))
136 timeout = 1;
137 else
138 timeout = cmd_timeout - now;
139
140 if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
141 ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
142 rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
143 else
144 rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout));
145
146 if (!rc)
147 ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
148 ctrl->slot_ctrl,
149 jiffies_to_msecs(jiffies - ctrl->cmd_started));
150}
151
152#define CC_ERRATUM_MASK (PCI_EXP_SLTCTL_PCC | \
153 PCI_EXP_SLTCTL_PIC | \
154 PCI_EXP_SLTCTL_AIC | \
155 PCI_EXP_SLTCTL_EIC)
156
157static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
158 u16 mask, bool wait)
159{
160 struct pci_dev *pdev = ctrl_dev(ctrl);
161 u16 slot_ctrl_orig, slot_ctrl;
162
163 mutex_lock(&ctrl->ctrl_lock);
164
165 /*
166 * Always wait for any previous command that might still be in progress
167 */
168 pcie_wait_cmd(ctrl);
169
170 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
171 if (PCI_POSSIBLE_ERROR(slot_ctrl)) {
172 ctrl_info(ctrl, "%s: no response from device\n", __func__);
173 goto out;
174 }
175
176 slot_ctrl_orig = slot_ctrl;
177 slot_ctrl &= ~mask;
178 slot_ctrl |= (cmd & mask);
179 ctrl->cmd_busy = 1;
180 smp_mb();
181 ctrl->slot_ctrl = slot_ctrl;
182 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
183 ctrl->cmd_started = jiffies;
184
185 /*
186 * Controllers with the Intel CF118 and similar errata advertise
187 * Command Completed support, but they only set Command Completed
188 * if we change the "Control" bits for power, power indicator,
189 * attention indicator, or interlock. If we only change the
190 * "Enable" bits, they never set the Command Completed bit.
191 */
192 if (pdev->broken_cmd_compl &&
193 (slot_ctrl_orig & CC_ERRATUM_MASK) == (slot_ctrl & CC_ERRATUM_MASK))
194 ctrl->cmd_busy = 0;
195
196 /*
197 * Optionally wait for the hardware to be ready for a new command,
198 * indicating completion of the above issued command.
199 */
200 if (wait)
201 pcie_wait_cmd(ctrl);
202
203out:
204 mutex_unlock(&ctrl->ctrl_lock);
205}
206
207/**
208 * pcie_write_cmd - Issue controller command
209 * @ctrl: controller to which the command is issued
210 * @cmd: command value written to slot control register
211 * @mask: bitmask of slot control register to be modified
212 */
213static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
214{
215 pcie_do_write_cmd(ctrl, cmd, mask, true);
216}
217
218/* Same as above without waiting for the hardware to latch */
219static void pcie_write_cmd_nowait(struct controller *ctrl, u16 cmd, u16 mask)
220{
221 pcie_do_write_cmd(ctrl, cmd, mask, false);
222}
223
224/**
225 * pciehp_check_link_active() - Is the link active
226 * @ctrl: PCIe hotplug controller
227 *
228 * Check whether the downstream link is currently active. Note it is
229 * possible that the card is removed immediately after this so the
230 * caller may need to take it into account.
231 *
232 * If the hotplug controller itself is not available anymore returns
233 * %-ENODEV.
234 */
235int pciehp_check_link_active(struct controller *ctrl)
236{
237 struct pci_dev *pdev = ctrl_dev(ctrl);
238 u16 lnk_status;
239 int ret;
240
241 ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
242 if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(lnk_status))
243 return -ENODEV;
244
245 ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
246 ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
247
248 return ret;
249}
250
251static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
252{
253 u32 l;
254 int count = 0;
255 int delay = 1000, step = 20;
256 bool found = false;
257
258 do {
259 found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
260 count++;
261
262 if (found)
263 break;
264
265 msleep(step);
266 delay -= step;
267 } while (delay > 0);
268
269 if (count > 1)
270 pr_debug("pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
271 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
272 PCI_FUNC(devfn), count, step, l);
273
274 return found;
275}
276
277static void pcie_wait_for_presence(struct pci_dev *pdev)
278{
279 int timeout = 1250;
280 u16 slot_status;
281
282 do {
283 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
284 if (slot_status & PCI_EXP_SLTSTA_PDS)
285 return;
286 msleep(10);
287 timeout -= 10;
288 } while (timeout > 0);
289}
290
291int pciehp_check_link_status(struct controller *ctrl)
292{
293 struct pci_dev *pdev = ctrl_dev(ctrl);
294 bool found;
295 u16 lnk_status;
296
297 if (!pcie_wait_for_link(pdev, true)) {
298 ctrl_info(ctrl, "Slot(%s): No link\n", slot_name(ctrl));
299 return -1;
300 }
301
302 if (ctrl->inband_presence_disabled)
303 pcie_wait_for_presence(pdev);
304
305 found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
306 PCI_DEVFN(0, 0));
307
308 /* ignore link or presence changes up to this point */
309 if (found)
310 atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
311 &ctrl->pending_events);
312
313 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
314 ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
315 if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
316 !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
317 ctrl_info(ctrl, "Slot(%s): Cannot train link: status %#06x\n",
318 slot_name(ctrl), lnk_status);
319 return -1;
320 }
321
322 __pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
323
324 if (!found) {
325 ctrl_info(ctrl, "Slot(%s): No device found\n",
326 slot_name(ctrl));
327 return -1;
328 }
329
330 return 0;
331}
332
333static int __pciehp_link_set(struct controller *ctrl, bool enable)
334{
335 struct pci_dev *pdev = ctrl_dev(ctrl);
336
337 pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,
338 PCI_EXP_LNKCTL_LD,
339 enable ? 0 : PCI_EXP_LNKCTL_LD);
340
341 return 0;
342}
343
344static int pciehp_link_enable(struct controller *ctrl)
345{
346 return __pciehp_link_set(ctrl, true);
347}
348
349int pciehp_get_raw_indicator_status(struct hotplug_slot *hotplug_slot,
350 u8 *status)
351{
352 struct controller *ctrl = to_ctrl(hotplug_slot);
353 struct pci_dev *pdev = ctrl_dev(ctrl);
354 u16 slot_ctrl;
355
356 pci_config_pm_runtime_get(pdev);
357 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
358 pci_config_pm_runtime_put(pdev);
359 *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6;
360 return 0;
361}
362
363int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status)
364{
365 struct controller *ctrl = to_ctrl(hotplug_slot);
366 struct pci_dev *pdev = ctrl_dev(ctrl);
367 u16 slot_ctrl;
368
369 pci_config_pm_runtime_get(pdev);
370 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
371 pci_config_pm_runtime_put(pdev);
372 ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
373 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
374
375 switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
376 case PCI_EXP_SLTCTL_ATTN_IND_ON:
377 *status = 1; /* On */
378 break;
379 case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
380 *status = 2; /* Blink */
381 break;
382 case PCI_EXP_SLTCTL_ATTN_IND_OFF:
383 *status = 0; /* Off */
384 break;
385 default:
386 *status = 0xFF;
387 break;
388 }
389
390 return 0;
391}
392
393void pciehp_get_power_status(struct controller *ctrl, u8 *status)
394{
395 struct pci_dev *pdev = ctrl_dev(ctrl);
396 u16 slot_ctrl;
397
398 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
399 ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
400 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
401
402 switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
403 case PCI_EXP_SLTCTL_PWR_ON:
404 *status = 1; /* On */
405 break;
406 case PCI_EXP_SLTCTL_PWR_OFF:
407 *status = 0; /* Off */
408 break;
409 default:
410 *status = 0xFF;
411 break;
412 }
413}
414
415void pciehp_get_latch_status(struct controller *ctrl, u8 *status)
416{
417 struct pci_dev *pdev = ctrl_dev(ctrl);
418 u16 slot_status;
419
420 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
421 *status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
422}
423
424/**
425 * pciehp_card_present() - Is the card present
426 * @ctrl: PCIe hotplug controller
427 *
428 * Function checks whether the card is currently present in the slot and
429 * in that case returns true. Note it is possible that the card is
430 * removed immediately after the check so the caller may need to take
431 * this into account.
432 *
433 * It the hotplug controller itself is not available anymore returns
434 * %-ENODEV.
435 */
436int pciehp_card_present(struct controller *ctrl)
437{
438 struct pci_dev *pdev = ctrl_dev(ctrl);
439 u16 slot_status;
440 int ret;
441
442 ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
443 if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(slot_status))
444 return -ENODEV;
445
446 return !!(slot_status & PCI_EXP_SLTSTA_PDS);
447}
448
449/**
450 * pciehp_card_present_or_link_active() - whether given slot is occupied
451 * @ctrl: PCIe hotplug controller
452 *
453 * Unlike pciehp_card_present(), which determines presence solely from the
454 * Presence Detect State bit, this helper also returns true if the Link Active
455 * bit is set. This is a concession to broken hotplug ports which hardwire
456 * Presence Detect State to zero, such as Wilocity's [1ae9:0200].
457 *
458 * Returns: %1 if the slot is occupied and %0 if it is not. If the hotplug
459 * port is not present anymore returns %-ENODEV.
460 */
461int pciehp_card_present_or_link_active(struct controller *ctrl)
462{
463 int ret;
464
465 ret = pciehp_card_present(ctrl);
466 if (ret)
467 return ret;
468
469 return pciehp_check_link_active(ctrl);
470}
471
472int pciehp_query_power_fault(struct controller *ctrl)
473{
474 struct pci_dev *pdev = ctrl_dev(ctrl);
475 u16 slot_status;
476
477 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
478 return !!(slot_status & PCI_EXP_SLTSTA_PFD);
479}
480
481int pciehp_set_raw_indicator_status(struct hotplug_slot *hotplug_slot,
482 u8 status)
483{
484 struct controller *ctrl = to_ctrl(hotplug_slot);
485 struct pci_dev *pdev = ctrl_dev(ctrl);
486
487 pci_config_pm_runtime_get(pdev);
488
489 /* Attention and Power Indicator Control bits are supported */
490 pcie_write_cmd_nowait(ctrl, FIELD_PREP(PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC, status),
491 PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
492 pci_config_pm_runtime_put(pdev);
493 return 0;
494}
495
496/**
497 * pciehp_set_indicators() - set attention indicator, power indicator, or both
498 * @ctrl: PCIe hotplug controller
499 * @pwr: one of:
500 * PCI_EXP_SLTCTL_PWR_IND_ON
501 * PCI_EXP_SLTCTL_PWR_IND_BLINK
502 * PCI_EXP_SLTCTL_PWR_IND_OFF
503 * @attn: one of:
504 * PCI_EXP_SLTCTL_ATTN_IND_ON
505 * PCI_EXP_SLTCTL_ATTN_IND_BLINK
506 * PCI_EXP_SLTCTL_ATTN_IND_OFF
507 *
508 * Either @pwr or @attn can also be INDICATOR_NOOP to leave that indicator
509 * unchanged.
510 */
511void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn)
512{
513 u16 cmd = 0, mask = 0;
514
515 if (PWR_LED(ctrl) && pwr != INDICATOR_NOOP) {
516 cmd |= (pwr & PCI_EXP_SLTCTL_PIC);
517 mask |= PCI_EXP_SLTCTL_PIC;
518 }
519
520 if (ATTN_LED(ctrl) && attn != INDICATOR_NOOP) {
521 cmd |= (attn & PCI_EXP_SLTCTL_AIC);
522 mask |= PCI_EXP_SLTCTL_AIC;
523 }
524
525 if (cmd) {
526 pcie_write_cmd_nowait(ctrl, cmd, mask);
527 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
528 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
529 }
530}
531
532int pciehp_power_on_slot(struct controller *ctrl)
533{
534 struct pci_dev *pdev = ctrl_dev(ctrl);
535 u16 slot_status;
536 int retval;
537
538 /* Clear power-fault bit from previous power failures */
539 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
540 if (slot_status & PCI_EXP_SLTSTA_PFD)
541 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
542 PCI_EXP_SLTSTA_PFD);
543 ctrl->power_fault_detected = 0;
544
545 pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
546 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
547 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
548 PCI_EXP_SLTCTL_PWR_ON);
549
550 retval = pciehp_link_enable(ctrl);
551 if (retval)
552 ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
553
554 return retval;
555}
556
557void pciehp_power_off_slot(struct controller *ctrl)
558{
559 pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
560 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
561 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
562 PCI_EXP_SLTCTL_PWR_OFF);
563}
564
565static void pciehp_ignore_dpc_link_change(struct controller *ctrl,
566 struct pci_dev *pdev, int irq)
567{
568 /*
569 * Ignore link changes which occurred while waiting for DPC recovery.
570 * Could be several if DPC triggered multiple times consecutively.
571 */
572 synchronize_hardirq(irq);
573 atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events);
574 if (pciehp_poll_mode)
575 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
576 PCI_EXP_SLTSTA_DLLSC);
577 ctrl_info(ctrl, "Slot(%s): Link Down/Up ignored (recovered by DPC)\n",
578 slot_name(ctrl));
579
580 /*
581 * If the link is unexpectedly down after successful recovery,
582 * the corresponding link change may have been ignored above.
583 * Synthesize it to ensure that it is acted on.
584 */
585 down_read_nested(&ctrl->reset_lock, ctrl->depth);
586 if (!pciehp_check_link_active(ctrl))
587 pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);
588 up_read(&ctrl->reset_lock);
589}
590
591static irqreturn_t pciehp_isr(int irq, void *dev_id)
592{
593 struct controller *ctrl = (struct controller *)dev_id;
594 struct pci_dev *pdev = ctrl_dev(ctrl);
595 struct device *parent = pdev->dev.parent;
596 u16 status, events = 0;
597
598 /*
599 * Interrupts only occur in D3hot or shallower and only if enabled
600 * in the Slot Control register (PCIe r4.0, sec 6.7.3.4).
601 */
602 if (pdev->current_state == PCI_D3cold ||
603 (!(ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE) && !pciehp_poll_mode))
604 return IRQ_NONE;
605
606 /*
607 * Keep the port accessible by holding a runtime PM ref on its parent.
608 * Defer resume of the parent to the IRQ thread if it's suspended.
609 * Mask the interrupt until then.
610 */
611 if (parent) {
612 pm_runtime_get_noresume(parent);
613 if (!pm_runtime_active(parent)) {
614 pm_runtime_put(parent);
615 disable_irq_nosync(irq);
616 atomic_or(RERUN_ISR, &ctrl->pending_events);
617 return IRQ_WAKE_THREAD;
618 }
619 }
620
621read_status:
622 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
623 if (PCI_POSSIBLE_ERROR(status)) {
624 ctrl_info(ctrl, "%s: no response from device\n", __func__);
625 if (parent)
626 pm_runtime_put(parent);
627 return IRQ_NONE;
628 }
629
630 /*
631 * Slot Status contains plain status bits as well as event
632 * notification bits; right now we only want the event bits.
633 */
634 status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
635 PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
636 PCI_EXP_SLTSTA_DLLSC;
637
638 /*
639 * If we've already reported a power fault, don't report it again
640 * until we've done something to handle it.
641 */
642 if (ctrl->power_fault_detected)
643 status &= ~PCI_EXP_SLTSTA_PFD;
644 else if (status & PCI_EXP_SLTSTA_PFD)
645 ctrl->power_fault_detected = true;
646
647 events |= status;
648 if (!events) {
649 if (parent)
650 pm_runtime_put(parent);
651 return IRQ_NONE;
652 }
653
654 if (status) {
655 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status);
656
657 /*
658 * In MSI mode, all event bits must be zero before the port
659 * will send a new interrupt (PCIe Base Spec r5.0 sec 6.7.3.4).
660 * So re-read the Slot Status register in case a bit was set
661 * between read and write.
662 */
663 if (pci_dev_msi_enabled(pdev) && !pciehp_poll_mode)
664 goto read_status;
665 }
666
667 ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
668 if (parent)
669 pm_runtime_put(parent);
670
671 /*
672 * Command Completed notifications are not deferred to the
673 * IRQ thread because it may be waiting for their arrival.
674 */
675 if (events & PCI_EXP_SLTSTA_CC) {
676 ctrl->cmd_busy = 0;
677 smp_mb();
678 wake_up(&ctrl->queue);
679
680 if (events == PCI_EXP_SLTSTA_CC)
681 return IRQ_HANDLED;
682
683 events &= ~PCI_EXP_SLTSTA_CC;
684 }
685
686 if (pdev->ignore_hotplug) {
687 ctrl_dbg(ctrl, "ignoring hotplug event %#06x\n", events);
688 return IRQ_HANDLED;
689 }
690
691 /* Save pending events for consumption by IRQ thread. */
692 atomic_or(events, &ctrl->pending_events);
693 return IRQ_WAKE_THREAD;
694}
695
696static irqreturn_t pciehp_ist(int irq, void *dev_id)
697{
698 struct controller *ctrl = (struct controller *)dev_id;
699 struct pci_dev *pdev = ctrl_dev(ctrl);
700 irqreturn_t ret;
701 u32 events;
702
703 ctrl->ist_running = true;
704 pci_config_pm_runtime_get(pdev);
705
706 /* rerun pciehp_isr() if the port was inaccessible on interrupt */
707 if (atomic_fetch_and(~RERUN_ISR, &ctrl->pending_events) & RERUN_ISR) {
708 ret = pciehp_isr(irq, dev_id);
709 enable_irq(irq);
710 if (ret != IRQ_WAKE_THREAD)
711 goto out;
712 }
713
714 synchronize_hardirq(irq);
715 events = atomic_xchg(&ctrl->pending_events, 0);
716 if (!events) {
717 ret = IRQ_NONE;
718 goto out;
719 }
720
721 /* Check Attention Button Pressed */
722 if (events & PCI_EXP_SLTSTA_ABP)
723 pciehp_handle_button_press(ctrl);
724
725 /* Check Power Fault Detected */
726 if (events & PCI_EXP_SLTSTA_PFD) {
727 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
728 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
729 PCI_EXP_SLTCTL_ATTN_IND_ON);
730 }
731
732 /*
733 * Ignore Link Down/Up events caused by Downstream Port Containment
734 * if recovery from the error succeeded.
735 */
736 if ((events & PCI_EXP_SLTSTA_DLLSC) && pci_dpc_recovered(pdev) &&
737 ctrl->state == ON_STATE) {
738 events &= ~PCI_EXP_SLTSTA_DLLSC;
739 pciehp_ignore_dpc_link_change(ctrl, pdev, irq);
740 }
741
742 /*
743 * Disable requests have higher priority than Presence Detect Changed
744 * or Data Link Layer State Changed events.
745 */
746 down_read_nested(&ctrl->reset_lock, ctrl->depth);
747 if (events & DISABLE_SLOT)
748 pciehp_handle_disable_request(ctrl);
749 else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC))
750 pciehp_handle_presence_or_link_change(ctrl, events);
751 up_read(&ctrl->reset_lock);
752
753 ret = IRQ_HANDLED;
754out:
755 pci_config_pm_runtime_put(pdev);
756 ctrl->ist_running = false;
757 wake_up(&ctrl->requester);
758 return ret;
759}
760
761static int pciehp_poll(void *data)
762{
763 struct controller *ctrl = data;
764
765 schedule_timeout_idle(10 * HZ); /* start with 10 sec delay */
766
767 while (!kthread_should_stop()) {
768 /* poll for interrupt events or user requests */
769 while (pciehp_isr(IRQ_NOTCONNECTED, ctrl) == IRQ_WAKE_THREAD ||
770 atomic_read(&ctrl->pending_events))
771 pciehp_ist(IRQ_NOTCONNECTED, ctrl);
772
773 if (pciehp_poll_time <= 0 || pciehp_poll_time > 60)
774 pciehp_poll_time = 2; /* clamp to sane value */
775
776 schedule_timeout_idle(pciehp_poll_time * HZ);
777 }
778
779 return 0;
780}
781
782static void pcie_enable_notification(struct controller *ctrl)
783{
784 u16 cmd, mask;
785
786 /*
787 * TBD: Power fault detected software notification support.
788 *
789 * Power fault detected software notification is not enabled
790 * now, because it caused power fault detected interrupt storm
791 * on some machines. On those machines, power fault detected
792 * bit in the slot status register was set again immediately
793 * when it is cleared in the interrupt service routine, and
794 * next power fault detected interrupt was notified again.
795 */
796
797 /*
798 * Always enable link events: thus link-up and link-down shall
799 * always be treated as hotplug and unplug respectively. Enable
800 * presence detect only if Attention Button is not present.
801 */
802 cmd = PCI_EXP_SLTCTL_DLLSCE;
803 if (ATTN_BUTTN(ctrl))
804 cmd |= PCI_EXP_SLTCTL_ABPE;
805 else
806 cmd |= PCI_EXP_SLTCTL_PDCE;
807 if (!pciehp_poll_mode)
808 cmd |= PCI_EXP_SLTCTL_HPIE;
809 if (!pciehp_poll_mode && !NO_CMD_CMPL(ctrl))
810 cmd |= PCI_EXP_SLTCTL_CCIE;
811
812 mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
813 PCI_EXP_SLTCTL_PFDE |
814 PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
815 PCI_EXP_SLTCTL_DLLSCE);
816
817 pcie_write_cmd_nowait(ctrl, cmd, mask);
818 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
819 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
820}
821
822static void pcie_disable_notification(struct controller *ctrl)
823{
824 u16 mask;
825
826 mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
827 PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
828 PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
829 PCI_EXP_SLTCTL_DLLSCE);
830 pcie_write_cmd(ctrl, 0, mask);
831 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
832 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
833}
834
835void pcie_clear_hotplug_events(struct controller *ctrl)
836{
837 pcie_capability_write_word(ctrl_dev(ctrl), PCI_EXP_SLTSTA,
838 PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
839}
840
841void pcie_enable_interrupt(struct controller *ctrl)
842{
843 u16 mask;
844
845 mask = PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE;
846 pcie_write_cmd(ctrl, mask, mask);
847}
848
849void pcie_disable_interrupt(struct controller *ctrl)
850{
851 u16 mask;
852
853 /*
854 * Mask hot-plug interrupt to prevent it triggering immediately
855 * when the link goes inactive (we still get PME when any of the
856 * enabled events is detected). Same goes with Link Layer State
857 * changed event which generates PME immediately when the link goes
858 * inactive so mask it as well.
859 */
860 mask = PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE;
861 pcie_write_cmd(ctrl, 0, mask);
862}
863
864/**
865 * pciehp_slot_reset() - ignore link event caused by error-induced hot reset
866 * @dev: PCI Express port service device
867 *
868 * Called from pcie_portdrv_slot_reset() after AER or DPC initiated a reset
869 * further up in the hierarchy to recover from an error. The reset was
870 * propagated down to this hotplug port. Ignore the resulting link flap.
871 * If the link failed to retrain successfully, synthesize the ignored event.
872 * Surprise removal during reset is detected through Presence Detect Changed.
873 */
874int pciehp_slot_reset(struct pcie_device *dev)
875{
876 struct controller *ctrl = get_service_data(dev);
877
878 if (ctrl->state != ON_STATE)
879 return 0;
880
881 pcie_capability_write_word(dev->port, PCI_EXP_SLTSTA,
882 PCI_EXP_SLTSTA_DLLSC);
883
884 if (!pciehp_check_link_active(ctrl))
885 pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);
886
887 return 0;
888}
889
890/*
891 * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
892 * bus reset of the bridge, but at the same time we want to ensure that it is
893 * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
894 * disable link state notification and presence detection change notification
895 * momentarily, if we see that they could interfere. Also, clear any spurious
896 * events after.
897 */
898int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
899{
900 struct controller *ctrl = to_ctrl(hotplug_slot);
901 struct pci_dev *pdev = ctrl_dev(ctrl);
902 u16 stat_mask = 0, ctrl_mask = 0;
903 int rc;
904
905 if (probe)
906 return 0;
907
908 down_write_nested(&ctrl->reset_lock, ctrl->depth);
909
910 if (!ATTN_BUTTN(ctrl)) {
911 ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
912 stat_mask |= PCI_EXP_SLTSTA_PDC;
913 }
914 ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
915 stat_mask |= PCI_EXP_SLTSTA_DLLSC;
916
917 pcie_write_cmd(ctrl, 0, ctrl_mask);
918 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
919 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
920
921 rc = pci_bridge_secondary_bus_reset(ctrl->pcie->port);
922
923 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
924 pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
925 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
926 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
927
928 up_write(&ctrl->reset_lock);
929 return rc;
930}
931
932int pcie_init_notification(struct controller *ctrl)
933{
934 if (pciehp_request_irq(ctrl))
935 return -1;
936 pcie_enable_notification(ctrl);
937 ctrl->notification_enabled = 1;
938 return 0;
939}
940
941void pcie_shutdown_notification(struct controller *ctrl)
942{
943 if (ctrl->notification_enabled) {
944 pcie_disable_notification(ctrl);
945 pciehp_free_irq(ctrl);
946 ctrl->notification_enabled = 0;
947 }
948}
949
950static inline void dbg_ctrl(struct controller *ctrl)
951{
952 struct pci_dev *pdev = ctrl->pcie->port;
953 u16 reg16;
954
955 ctrl_dbg(ctrl, "Slot Capabilities : 0x%08x\n", ctrl->slot_cap);
956 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, ®16);
957 ctrl_dbg(ctrl, "Slot Status : 0x%04x\n", reg16);
958 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, ®16);
959 ctrl_dbg(ctrl, "Slot Control : 0x%04x\n", reg16);
960}
961
962#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
963
964static inline int pcie_hotplug_depth(struct pci_dev *dev)
965{
966 struct pci_bus *bus = dev->bus;
967 int depth = 0;
968
969 while (bus->parent) {
970 bus = bus->parent;
971 if (bus->self && bus->self->is_hotplug_bridge)
972 depth++;
973 }
974
975 return depth;
976}
977
978struct controller *pcie_init(struct pcie_device *dev)
979{
980 struct controller *ctrl;
981 u32 slot_cap, slot_cap2;
982 u8 poweron;
983 struct pci_dev *pdev = dev->port;
984 struct pci_bus *subordinate = pdev->subordinate;
985
986 ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
987 if (!ctrl)
988 return NULL;
989
990 ctrl->pcie = dev;
991 ctrl->depth = pcie_hotplug_depth(dev->port);
992 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
993
994 if (pdev->hotplug_user_indicators)
995 slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP);
996
997 /*
998 * We assume no Thunderbolt controllers support Command Complete events,
999 * but some controllers falsely claim they do.
1000 */
1001 if (pdev->is_thunderbolt)
1002 slot_cap |= PCI_EXP_SLTCAP_NCCS;
1003
1004 ctrl->slot_cap = slot_cap;
1005 mutex_init(&ctrl->ctrl_lock);
1006 mutex_init(&ctrl->state_lock);
1007 init_rwsem(&ctrl->reset_lock);
1008 init_waitqueue_head(&ctrl->requester);
1009 init_waitqueue_head(&ctrl->queue);
1010 INIT_DELAYED_WORK(&ctrl->button_work, pciehp_queue_pushbutton_work);
1011 dbg_ctrl(ctrl);
1012
1013 down_read(&pci_bus_sem);
1014 ctrl->state = list_empty(&subordinate->devices) ? OFF_STATE : ON_STATE;
1015 up_read(&pci_bus_sem);
1016
1017 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP2, &slot_cap2);
1018 if (slot_cap2 & PCI_EXP_SLTCAP2_IBPD) {
1019 pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_IBPD_DISABLE,
1020 PCI_EXP_SLTCTL_IBPD_DISABLE);
1021 ctrl->inband_presence_disabled = 1;
1022 }
1023
1024 if (dmi_first_match(inband_presence_disabled_dmi_table))
1025 ctrl->inband_presence_disabled = 1;
1026
1027 /* Clear all remaining event bits in Slot Status register. */
1028 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
1029 PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
1030 PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_CC |
1031 PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC);
1032
1033 ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c IbPresDis%c LLActRep%c%s\n",
1034 FIELD_GET(PCI_EXP_SLTCAP_PSN, slot_cap),
1035 FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
1036 FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
1037 FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
1038 FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
1039 FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
1040 FLAG(slot_cap, PCI_EXP_SLTCAP_HPC),
1041 FLAG(slot_cap, PCI_EXP_SLTCAP_HPS),
1042 FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
1043 FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
1044 FLAG(slot_cap2, PCI_EXP_SLTCAP2_IBPD),
1045 FLAG(pdev->link_active_reporting, true),
1046 pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : "");
1047
1048 /*
1049 * If empty slot's power status is on, turn power off. The IRQ isn't
1050 * requested yet, so avoid triggering a notification with this command.
1051 */
1052 if (POWER_CTRL(ctrl)) {
1053 pciehp_get_power_status(ctrl, &poweron);
1054 if (!pciehp_card_present_or_link_active(ctrl) && poweron) {
1055 pcie_disable_notification(ctrl);
1056 pciehp_power_off_slot(ctrl);
1057 }
1058 }
1059
1060 pdev = pci_get_slot(subordinate, PCI_DEVFN(0, 0));
1061 if (pdev)
1062 ctrl->dsn = pci_get_dsn(pdev);
1063 pci_dev_put(pdev);
1064
1065 return ctrl;
1066}
1067
1068void pciehp_release_ctrl(struct controller *ctrl)
1069{
1070 cancel_delayed_work_sync(&ctrl->button_work);
1071 kfree(ctrl);
1072}
1073
1074static void quirk_cmd_compl(struct pci_dev *pdev)
1075{
1076 u32 slot_cap;
1077
1078 if (pci_is_pcie(pdev)) {
1079 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
1080 if (slot_cap & PCI_EXP_SLTCAP_HPC &&
1081 !(slot_cap & PCI_EXP_SLTCAP_NCCS))
1082 pdev->broken_cmd_compl = 1;
1083 }
1084}
1085DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
1086 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1087DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x010e,
1088 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1089DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0110,
1090 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1091DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
1092 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1093DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401,
1094 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1095DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_HXT, 0x0401,
1096 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * PCI Express PCI Hot Plug Driver
4 *
5 * Copyright (C) 1995,2001 Compaq Computer Corporation
6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
7 * Copyright (C) 2001 IBM Corp.
8 * Copyright (C) 2003-2004 Intel Corporation
9 *
10 * All rights reserved.
11 *
12 * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com>
13 */
14
15#define dev_fmt(fmt) "pciehp: " fmt
16
17#include <linux/bitfield.h>
18#include <linux/dmi.h>
19#include <linux/kernel.h>
20#include <linux/types.h>
21#include <linux/jiffies.h>
22#include <linux/kthread.h>
23#include <linux/pci.h>
24#include <linux/pm_runtime.h>
25#include <linux/interrupt.h>
26#include <linux/slab.h>
27
28#include "../pci.h"
29#include "pciehp.h"
30
31static const struct dmi_system_id inband_presence_disabled_dmi_table[] = {
32 /*
33 * Match all Dell systems, as some Dell systems have inband
34 * presence disabled on NVMe slots (but don't support the bit to
35 * report it). Setting inband presence disabled should have no
36 * negative effect, except on broken hotplug slots that never
37 * assert presence detect--and those will still work, they will
38 * just have a bit of extra delay before being probed.
39 */
40 {
41 .ident = "Dell System",
42 .matches = {
43 DMI_MATCH(DMI_OEM_STRING, "Dell System"),
44 },
45 },
46 {}
47};
48
49static inline struct pci_dev *ctrl_dev(struct controller *ctrl)
50{
51 return ctrl->pcie->port;
52}
53
54static irqreturn_t pciehp_isr(int irq, void *dev_id);
55static irqreturn_t pciehp_ist(int irq, void *dev_id);
56static int pciehp_poll(void *data);
57
58static inline int pciehp_request_irq(struct controller *ctrl)
59{
60 int retval, irq = ctrl->pcie->irq;
61
62 if (pciehp_poll_mode) {
63 ctrl->poll_thread = kthread_run(&pciehp_poll, ctrl,
64 "pciehp_poll-%s",
65 slot_name(ctrl));
66 return PTR_ERR_OR_ZERO(ctrl->poll_thread);
67 }
68
69 /* Installs the interrupt handler */
70 retval = request_threaded_irq(irq, pciehp_isr, pciehp_ist,
71 IRQF_SHARED, "pciehp", ctrl);
72 if (retval)
73 ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
74 irq);
75 return retval;
76}
77
78static inline void pciehp_free_irq(struct controller *ctrl)
79{
80 if (pciehp_poll_mode)
81 kthread_stop(ctrl->poll_thread);
82 else
83 free_irq(ctrl->pcie->irq, ctrl);
84}
85
86static int pcie_poll_cmd(struct controller *ctrl, int timeout)
87{
88 struct pci_dev *pdev = ctrl_dev(ctrl);
89 u16 slot_status;
90
91 do {
92 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
93 if (PCI_POSSIBLE_ERROR(slot_status)) {
94 ctrl_info(ctrl, "%s: no response from device\n",
95 __func__);
96 return 0;
97 }
98
99 if (slot_status & PCI_EXP_SLTSTA_CC) {
100 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
101 PCI_EXP_SLTSTA_CC);
102 ctrl->cmd_busy = 0;
103 smp_mb();
104 return 1;
105 }
106 msleep(10);
107 timeout -= 10;
108 } while (timeout >= 0);
109 return 0; /* timeout */
110}
111
112static void pcie_wait_cmd(struct controller *ctrl)
113{
114 unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
115 unsigned long duration = msecs_to_jiffies(msecs);
116 unsigned long cmd_timeout = ctrl->cmd_started + duration;
117 unsigned long now, timeout;
118 int rc;
119
120 /*
121 * If the controller does not generate notifications for command
122 * completions, we never need to wait between writes.
123 */
124 if (NO_CMD_CMPL(ctrl))
125 return;
126
127 if (!ctrl->cmd_busy)
128 return;
129
130 /*
131 * Even if the command has already timed out, we want to call
132 * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
133 */
134 now = jiffies;
135 if (time_before_eq(cmd_timeout, now))
136 timeout = 1;
137 else
138 timeout = cmd_timeout - now;
139
140 if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
141 ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
142 rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
143 else
144 rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout));
145
146 if (!rc)
147 ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
148 ctrl->slot_ctrl,
149 jiffies_to_msecs(jiffies - ctrl->cmd_started));
150}
151
152#define CC_ERRATUM_MASK (PCI_EXP_SLTCTL_PCC | \
153 PCI_EXP_SLTCTL_PIC | \
154 PCI_EXP_SLTCTL_AIC | \
155 PCI_EXP_SLTCTL_EIC)
156
157static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
158 u16 mask, bool wait)
159{
160 struct pci_dev *pdev = ctrl_dev(ctrl);
161 u16 slot_ctrl_orig, slot_ctrl;
162
163 mutex_lock(&ctrl->ctrl_lock);
164
165 /*
166 * Always wait for any previous command that might still be in progress
167 */
168 pcie_wait_cmd(ctrl);
169
170 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
171 if (PCI_POSSIBLE_ERROR(slot_ctrl)) {
172 ctrl_info(ctrl, "%s: no response from device\n", __func__);
173 goto out;
174 }
175
176 slot_ctrl_orig = slot_ctrl;
177 slot_ctrl &= ~mask;
178 slot_ctrl |= (cmd & mask);
179 ctrl->cmd_busy = 1;
180 smp_mb();
181 ctrl->slot_ctrl = slot_ctrl;
182 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
183 ctrl->cmd_started = jiffies;
184
185 /*
186 * Controllers with the Intel CF118 and similar errata advertise
187 * Command Completed support, but they only set Command Completed
188 * if we change the "Control" bits for power, power indicator,
189 * attention indicator, or interlock. If we only change the
190 * "Enable" bits, they never set the Command Completed bit.
191 */
192 if (pdev->broken_cmd_compl &&
193 (slot_ctrl_orig & CC_ERRATUM_MASK) == (slot_ctrl & CC_ERRATUM_MASK))
194 ctrl->cmd_busy = 0;
195
196 /*
197 * Optionally wait for the hardware to be ready for a new command,
198 * indicating completion of the above issued command.
199 */
200 if (wait)
201 pcie_wait_cmd(ctrl);
202
203out:
204 mutex_unlock(&ctrl->ctrl_lock);
205}
206
207/**
208 * pcie_write_cmd - Issue controller command
209 * @ctrl: controller to which the command is issued
210 * @cmd: command value written to slot control register
211 * @mask: bitmask of slot control register to be modified
212 */
213static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
214{
215 pcie_do_write_cmd(ctrl, cmd, mask, true);
216}
217
218/* Same as above without waiting for the hardware to latch */
219static void pcie_write_cmd_nowait(struct controller *ctrl, u16 cmd, u16 mask)
220{
221 pcie_do_write_cmd(ctrl, cmd, mask, false);
222}
223
224/**
225 * pciehp_check_link_active() - Is the link active
226 * @ctrl: PCIe hotplug controller
227 *
228 * Check whether the downstream link is currently active. Note it is
229 * possible that the card is removed immediately after this so the
230 * caller may need to take it into account.
231 *
232 * If the hotplug controller itself is not available anymore returns
233 * %-ENODEV.
234 */
235int pciehp_check_link_active(struct controller *ctrl)
236{
237 struct pci_dev *pdev = ctrl_dev(ctrl);
238 u16 lnk_status;
239 int ret;
240
241 ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
242 if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(lnk_status))
243 return -ENODEV;
244
245 ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
246 ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
247
248 return ret;
249}
250
251static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
252{
253 u32 l;
254 int count = 0;
255 int delay = 1000, step = 20;
256 bool found = false;
257
258 do {
259 found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
260 count++;
261
262 if (found)
263 break;
264
265 msleep(step);
266 delay -= step;
267 } while (delay > 0);
268
269 if (count > 1)
270 pr_debug("pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
271 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
272 PCI_FUNC(devfn), count, step, l);
273
274 return found;
275}
276
277static void pcie_wait_for_presence(struct pci_dev *pdev)
278{
279 int timeout = 1250;
280 u16 slot_status;
281
282 do {
283 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
284 if (slot_status & PCI_EXP_SLTSTA_PDS)
285 return;
286 msleep(10);
287 timeout -= 10;
288 } while (timeout > 0);
289}
290
291int pciehp_check_link_status(struct controller *ctrl)
292{
293 struct pci_dev *pdev = ctrl_dev(ctrl);
294 bool found;
295 u16 lnk_status;
296
297 if (!pcie_wait_for_link(pdev, true)) {
298 ctrl_info(ctrl, "Slot(%s): No link\n", slot_name(ctrl));
299 return -1;
300 }
301
302 if (ctrl->inband_presence_disabled)
303 pcie_wait_for_presence(pdev);
304
305 found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
306 PCI_DEVFN(0, 0));
307
308 /* ignore link or presence changes up to this point */
309 if (found)
310 atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
311 &ctrl->pending_events);
312
313 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
314 ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
315 if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
316 !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
317 ctrl_info(ctrl, "Slot(%s): Cannot train link: status %#06x\n",
318 slot_name(ctrl), lnk_status);
319 return -1;
320 }
321
322 pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
323
324 if (!found) {
325 ctrl_info(ctrl, "Slot(%s): No device found\n",
326 slot_name(ctrl));
327 return -1;
328 }
329
330 return 0;
331}
332
333static int __pciehp_link_set(struct controller *ctrl, bool enable)
334{
335 struct pci_dev *pdev = ctrl_dev(ctrl);
336
337 pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,
338 PCI_EXP_LNKCTL_LD,
339 enable ? 0 : PCI_EXP_LNKCTL_LD);
340
341 return 0;
342}
343
344static int pciehp_link_enable(struct controller *ctrl)
345{
346 return __pciehp_link_set(ctrl, true);
347}
348
349int pciehp_get_raw_indicator_status(struct hotplug_slot *hotplug_slot,
350 u8 *status)
351{
352 struct controller *ctrl = to_ctrl(hotplug_slot);
353 struct pci_dev *pdev = ctrl_dev(ctrl);
354 u16 slot_ctrl;
355
356 pci_config_pm_runtime_get(pdev);
357 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
358 pci_config_pm_runtime_put(pdev);
359 *status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6;
360 return 0;
361}
362
363int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status)
364{
365 struct controller *ctrl = to_ctrl(hotplug_slot);
366 struct pci_dev *pdev = ctrl_dev(ctrl);
367 u16 slot_ctrl;
368
369 pci_config_pm_runtime_get(pdev);
370 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
371 pci_config_pm_runtime_put(pdev);
372 ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
373 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
374
375 switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
376 case PCI_EXP_SLTCTL_ATTN_IND_ON:
377 *status = 1; /* On */
378 break;
379 case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
380 *status = 2; /* Blink */
381 break;
382 case PCI_EXP_SLTCTL_ATTN_IND_OFF:
383 *status = 0; /* Off */
384 break;
385 default:
386 *status = 0xFF;
387 break;
388 }
389
390 return 0;
391}
392
393void pciehp_get_power_status(struct controller *ctrl, u8 *status)
394{
395 struct pci_dev *pdev = ctrl_dev(ctrl);
396 u16 slot_ctrl;
397
398 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
399 ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
400 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
401
402 switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
403 case PCI_EXP_SLTCTL_PWR_ON:
404 *status = 1; /* On */
405 break;
406 case PCI_EXP_SLTCTL_PWR_OFF:
407 *status = 0; /* Off */
408 break;
409 default:
410 *status = 0xFF;
411 break;
412 }
413}
414
415void pciehp_get_latch_status(struct controller *ctrl, u8 *status)
416{
417 struct pci_dev *pdev = ctrl_dev(ctrl);
418 u16 slot_status;
419
420 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
421 *status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
422}
423
424/**
425 * pciehp_card_present() - Is the card present
426 * @ctrl: PCIe hotplug controller
427 *
428 * Function checks whether the card is currently present in the slot and
429 * in that case returns true. Note it is possible that the card is
430 * removed immediately after the check so the caller may need to take
431 * this into account.
432 *
433 * It the hotplug controller itself is not available anymore returns
434 * %-ENODEV.
435 */
436int pciehp_card_present(struct controller *ctrl)
437{
438 struct pci_dev *pdev = ctrl_dev(ctrl);
439 u16 slot_status;
440 int ret;
441
442 ret = pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
443 if (ret == PCIBIOS_DEVICE_NOT_FOUND || PCI_POSSIBLE_ERROR(slot_status))
444 return -ENODEV;
445
446 return !!(slot_status & PCI_EXP_SLTSTA_PDS);
447}
448
449/**
450 * pciehp_card_present_or_link_active() - whether given slot is occupied
451 * @ctrl: PCIe hotplug controller
452 *
453 * Unlike pciehp_card_present(), which determines presence solely from the
454 * Presence Detect State bit, this helper also returns true if the Link Active
455 * bit is set. This is a concession to broken hotplug ports which hardwire
456 * Presence Detect State to zero, such as Wilocity's [1ae9:0200].
457 *
458 * Returns: %1 if the slot is occupied and %0 if it is not. If the hotplug
459 * port is not present anymore returns %-ENODEV.
460 */
461int pciehp_card_present_or_link_active(struct controller *ctrl)
462{
463 int ret;
464
465 ret = pciehp_card_present(ctrl);
466 if (ret)
467 return ret;
468
469 return pciehp_check_link_active(ctrl);
470}
471
472int pciehp_query_power_fault(struct controller *ctrl)
473{
474 struct pci_dev *pdev = ctrl_dev(ctrl);
475 u16 slot_status;
476
477 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
478 return !!(slot_status & PCI_EXP_SLTSTA_PFD);
479}
480
481int pciehp_set_raw_indicator_status(struct hotplug_slot *hotplug_slot,
482 u8 status)
483{
484 struct controller *ctrl = to_ctrl(hotplug_slot);
485 struct pci_dev *pdev = ctrl_dev(ctrl);
486
487 pci_config_pm_runtime_get(pdev);
488 pcie_write_cmd_nowait(ctrl, FIELD_PREP(PCI_EXP_SLTCTL_AIC, status),
489 PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
490 pci_config_pm_runtime_put(pdev);
491 return 0;
492}
493
494/**
495 * pciehp_set_indicators() - set attention indicator, power indicator, or both
496 * @ctrl: PCIe hotplug controller
497 * @pwr: one of:
498 * PCI_EXP_SLTCTL_PWR_IND_ON
499 * PCI_EXP_SLTCTL_PWR_IND_BLINK
500 * PCI_EXP_SLTCTL_PWR_IND_OFF
501 * @attn: one of:
502 * PCI_EXP_SLTCTL_ATTN_IND_ON
503 * PCI_EXP_SLTCTL_ATTN_IND_BLINK
504 * PCI_EXP_SLTCTL_ATTN_IND_OFF
505 *
506 * Either @pwr or @attn can also be INDICATOR_NOOP to leave that indicator
507 * unchanged.
508 */
509void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn)
510{
511 u16 cmd = 0, mask = 0;
512
513 if (PWR_LED(ctrl) && pwr != INDICATOR_NOOP) {
514 cmd |= (pwr & PCI_EXP_SLTCTL_PIC);
515 mask |= PCI_EXP_SLTCTL_PIC;
516 }
517
518 if (ATTN_LED(ctrl) && attn != INDICATOR_NOOP) {
519 cmd |= (attn & PCI_EXP_SLTCTL_AIC);
520 mask |= PCI_EXP_SLTCTL_AIC;
521 }
522
523 if (cmd) {
524 pcie_write_cmd_nowait(ctrl, cmd, mask);
525 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
526 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
527 }
528}
529
530int pciehp_power_on_slot(struct controller *ctrl)
531{
532 struct pci_dev *pdev = ctrl_dev(ctrl);
533 u16 slot_status;
534 int retval;
535
536 /* Clear power-fault bit from previous power failures */
537 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
538 if (slot_status & PCI_EXP_SLTSTA_PFD)
539 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
540 PCI_EXP_SLTSTA_PFD);
541 ctrl->power_fault_detected = 0;
542
543 pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
544 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
545 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
546 PCI_EXP_SLTCTL_PWR_ON);
547
548 retval = pciehp_link_enable(ctrl);
549 if (retval)
550 ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
551
552 return retval;
553}
554
555void pciehp_power_off_slot(struct controller *ctrl)
556{
557 pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
558 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
559 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
560 PCI_EXP_SLTCTL_PWR_OFF);
561}
562
563static void pciehp_ignore_dpc_link_change(struct controller *ctrl,
564 struct pci_dev *pdev, int irq)
565{
566 /*
567 * Ignore link changes which occurred while waiting for DPC recovery.
568 * Could be several if DPC triggered multiple times consecutively.
569 */
570 synchronize_hardirq(irq);
571 atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events);
572 if (pciehp_poll_mode)
573 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
574 PCI_EXP_SLTSTA_DLLSC);
575 ctrl_info(ctrl, "Slot(%s): Link Down/Up ignored (recovered by DPC)\n",
576 slot_name(ctrl));
577
578 /*
579 * If the link is unexpectedly down after successful recovery,
580 * the corresponding link change may have been ignored above.
581 * Synthesize it to ensure that it is acted on.
582 */
583 down_read_nested(&ctrl->reset_lock, ctrl->depth);
584 if (!pciehp_check_link_active(ctrl))
585 pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);
586 up_read(&ctrl->reset_lock);
587}
588
589static irqreturn_t pciehp_isr(int irq, void *dev_id)
590{
591 struct controller *ctrl = (struct controller *)dev_id;
592 struct pci_dev *pdev = ctrl_dev(ctrl);
593 struct device *parent = pdev->dev.parent;
594 u16 status, events = 0;
595
596 /*
597 * Interrupts only occur in D3hot or shallower and only if enabled
598 * in the Slot Control register (PCIe r4.0, sec 6.7.3.4).
599 */
600 if (pdev->current_state == PCI_D3cold ||
601 (!(ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE) && !pciehp_poll_mode))
602 return IRQ_NONE;
603
604 /*
605 * Keep the port accessible by holding a runtime PM ref on its parent.
606 * Defer resume of the parent to the IRQ thread if it's suspended.
607 * Mask the interrupt until then.
608 */
609 if (parent) {
610 pm_runtime_get_noresume(parent);
611 if (!pm_runtime_active(parent)) {
612 pm_runtime_put(parent);
613 disable_irq_nosync(irq);
614 atomic_or(RERUN_ISR, &ctrl->pending_events);
615 return IRQ_WAKE_THREAD;
616 }
617 }
618
619read_status:
620 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
621 if (PCI_POSSIBLE_ERROR(status)) {
622 ctrl_info(ctrl, "%s: no response from device\n", __func__);
623 if (parent)
624 pm_runtime_put(parent);
625 return IRQ_NONE;
626 }
627
628 /*
629 * Slot Status contains plain status bits as well as event
630 * notification bits; right now we only want the event bits.
631 */
632 status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
633 PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
634 PCI_EXP_SLTSTA_DLLSC;
635
636 /*
637 * If we've already reported a power fault, don't report it again
638 * until we've done something to handle it.
639 */
640 if (ctrl->power_fault_detected)
641 status &= ~PCI_EXP_SLTSTA_PFD;
642 else if (status & PCI_EXP_SLTSTA_PFD)
643 ctrl->power_fault_detected = true;
644
645 events |= status;
646 if (!events) {
647 if (parent)
648 pm_runtime_put(parent);
649 return IRQ_NONE;
650 }
651
652 if (status) {
653 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status);
654
655 /*
656 * In MSI mode, all event bits must be zero before the port
657 * will send a new interrupt (PCIe Base Spec r5.0 sec 6.7.3.4).
658 * So re-read the Slot Status register in case a bit was set
659 * between read and write.
660 */
661 if (pci_dev_msi_enabled(pdev) && !pciehp_poll_mode)
662 goto read_status;
663 }
664
665 ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
666 if (parent)
667 pm_runtime_put(parent);
668
669 /*
670 * Command Completed notifications are not deferred to the
671 * IRQ thread because it may be waiting for their arrival.
672 */
673 if (events & PCI_EXP_SLTSTA_CC) {
674 ctrl->cmd_busy = 0;
675 smp_mb();
676 wake_up(&ctrl->queue);
677
678 if (events == PCI_EXP_SLTSTA_CC)
679 return IRQ_HANDLED;
680
681 events &= ~PCI_EXP_SLTSTA_CC;
682 }
683
684 if (pdev->ignore_hotplug) {
685 ctrl_dbg(ctrl, "ignoring hotplug event %#06x\n", events);
686 return IRQ_HANDLED;
687 }
688
689 /* Save pending events for consumption by IRQ thread. */
690 atomic_or(events, &ctrl->pending_events);
691 return IRQ_WAKE_THREAD;
692}
693
694static irqreturn_t pciehp_ist(int irq, void *dev_id)
695{
696 struct controller *ctrl = (struct controller *)dev_id;
697 struct pci_dev *pdev = ctrl_dev(ctrl);
698 irqreturn_t ret;
699 u32 events;
700
701 ctrl->ist_running = true;
702 pci_config_pm_runtime_get(pdev);
703
704 /* rerun pciehp_isr() if the port was inaccessible on interrupt */
705 if (atomic_fetch_and(~RERUN_ISR, &ctrl->pending_events) & RERUN_ISR) {
706 ret = pciehp_isr(irq, dev_id);
707 enable_irq(irq);
708 if (ret != IRQ_WAKE_THREAD)
709 goto out;
710 }
711
712 synchronize_hardirq(irq);
713 events = atomic_xchg(&ctrl->pending_events, 0);
714 if (!events) {
715 ret = IRQ_NONE;
716 goto out;
717 }
718
719 /* Check Attention Button Pressed */
720 if (events & PCI_EXP_SLTSTA_ABP)
721 pciehp_handle_button_press(ctrl);
722
723 /* Check Power Fault Detected */
724 if (events & PCI_EXP_SLTSTA_PFD) {
725 ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
726 pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
727 PCI_EXP_SLTCTL_ATTN_IND_ON);
728 }
729
730 /*
731 * Ignore Link Down/Up events caused by Downstream Port Containment
732 * if recovery from the error succeeded.
733 */
734 if ((events & PCI_EXP_SLTSTA_DLLSC) && pci_dpc_recovered(pdev) &&
735 ctrl->state == ON_STATE) {
736 events &= ~PCI_EXP_SLTSTA_DLLSC;
737 pciehp_ignore_dpc_link_change(ctrl, pdev, irq);
738 }
739
740 /*
741 * Disable requests have higher priority than Presence Detect Changed
742 * or Data Link Layer State Changed events.
743 */
744 down_read_nested(&ctrl->reset_lock, ctrl->depth);
745 if (events & DISABLE_SLOT)
746 pciehp_handle_disable_request(ctrl);
747 else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC))
748 pciehp_handle_presence_or_link_change(ctrl, events);
749 up_read(&ctrl->reset_lock);
750
751 ret = IRQ_HANDLED;
752out:
753 pci_config_pm_runtime_put(pdev);
754 ctrl->ist_running = false;
755 wake_up(&ctrl->requester);
756 return ret;
757}
758
759static int pciehp_poll(void *data)
760{
761 struct controller *ctrl = data;
762
763 schedule_timeout_idle(10 * HZ); /* start with 10 sec delay */
764
765 while (!kthread_should_stop()) {
766 /* poll for interrupt events or user requests */
767 while (pciehp_isr(IRQ_NOTCONNECTED, ctrl) == IRQ_WAKE_THREAD ||
768 atomic_read(&ctrl->pending_events))
769 pciehp_ist(IRQ_NOTCONNECTED, ctrl);
770
771 if (pciehp_poll_time <= 0 || pciehp_poll_time > 60)
772 pciehp_poll_time = 2; /* clamp to sane value */
773
774 schedule_timeout_idle(pciehp_poll_time * HZ);
775 }
776
777 return 0;
778}
779
780static void pcie_enable_notification(struct controller *ctrl)
781{
782 u16 cmd, mask;
783
784 /*
785 * TBD: Power fault detected software notification support.
786 *
787 * Power fault detected software notification is not enabled
788 * now, because it caused power fault detected interrupt storm
789 * on some machines. On those machines, power fault detected
790 * bit in the slot status register was set again immediately
791 * when it is cleared in the interrupt service routine, and
792 * next power fault detected interrupt was notified again.
793 */
794
795 /*
796 * Always enable link events: thus link-up and link-down shall
797 * always be treated as hotplug and unplug respectively. Enable
798 * presence detect only if Attention Button is not present.
799 */
800 cmd = PCI_EXP_SLTCTL_DLLSCE;
801 if (ATTN_BUTTN(ctrl))
802 cmd |= PCI_EXP_SLTCTL_ABPE;
803 else
804 cmd |= PCI_EXP_SLTCTL_PDCE;
805 if (!pciehp_poll_mode)
806 cmd |= PCI_EXP_SLTCTL_HPIE;
807 if (!pciehp_poll_mode && !NO_CMD_CMPL(ctrl))
808 cmd |= PCI_EXP_SLTCTL_CCIE;
809
810 mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
811 PCI_EXP_SLTCTL_PFDE |
812 PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
813 PCI_EXP_SLTCTL_DLLSCE);
814
815 pcie_write_cmd_nowait(ctrl, cmd, mask);
816 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
817 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
818}
819
820static void pcie_disable_notification(struct controller *ctrl)
821{
822 u16 mask;
823
824 mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
825 PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
826 PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
827 PCI_EXP_SLTCTL_DLLSCE);
828 pcie_write_cmd(ctrl, 0, mask);
829 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
830 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
831}
832
833void pcie_clear_hotplug_events(struct controller *ctrl)
834{
835 pcie_capability_write_word(ctrl_dev(ctrl), PCI_EXP_SLTSTA,
836 PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
837}
838
839void pcie_enable_interrupt(struct controller *ctrl)
840{
841 u16 mask;
842
843 mask = PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE;
844 pcie_write_cmd(ctrl, mask, mask);
845}
846
847void pcie_disable_interrupt(struct controller *ctrl)
848{
849 u16 mask;
850
851 /*
852 * Mask hot-plug interrupt to prevent it triggering immediately
853 * when the link goes inactive (we still get PME when any of the
854 * enabled events is detected). Same goes with Link Layer State
855 * changed event which generates PME immediately when the link goes
856 * inactive so mask it as well.
857 */
858 mask = PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_DLLSCE;
859 pcie_write_cmd(ctrl, 0, mask);
860}
861
862/**
863 * pciehp_slot_reset() - ignore link event caused by error-induced hot reset
864 * @dev: PCI Express port service device
865 *
866 * Called from pcie_portdrv_slot_reset() after AER or DPC initiated a reset
867 * further up in the hierarchy to recover from an error. The reset was
868 * propagated down to this hotplug port. Ignore the resulting link flap.
869 * If the link failed to retrain successfully, synthesize the ignored event.
870 * Surprise removal during reset is detected through Presence Detect Changed.
871 */
872int pciehp_slot_reset(struct pcie_device *dev)
873{
874 struct controller *ctrl = get_service_data(dev);
875
876 if (ctrl->state != ON_STATE)
877 return 0;
878
879 pcie_capability_write_word(dev->port, PCI_EXP_SLTSTA,
880 PCI_EXP_SLTSTA_DLLSC);
881
882 if (!pciehp_check_link_active(ctrl))
883 pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);
884
885 return 0;
886}
887
888/*
889 * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
890 * bus reset of the bridge, but at the same time we want to ensure that it is
891 * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
892 * disable link state notification and presence detection change notification
893 * momentarily, if we see that they could interfere. Also, clear any spurious
894 * events after.
895 */
896int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
897{
898 struct controller *ctrl = to_ctrl(hotplug_slot);
899 struct pci_dev *pdev = ctrl_dev(ctrl);
900 u16 stat_mask = 0, ctrl_mask = 0;
901 int rc;
902
903 if (probe)
904 return 0;
905
906 down_write_nested(&ctrl->reset_lock, ctrl->depth);
907
908 if (!ATTN_BUTTN(ctrl)) {
909 ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
910 stat_mask |= PCI_EXP_SLTSTA_PDC;
911 }
912 ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
913 stat_mask |= PCI_EXP_SLTSTA_DLLSC;
914
915 pcie_write_cmd(ctrl, 0, ctrl_mask);
916 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
917 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
918
919 rc = pci_bridge_secondary_bus_reset(ctrl->pcie->port);
920
921 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
922 pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
923 ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
924 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
925
926 up_write(&ctrl->reset_lock);
927 return rc;
928}
929
930int pcie_init_notification(struct controller *ctrl)
931{
932 if (pciehp_request_irq(ctrl))
933 return -1;
934 pcie_enable_notification(ctrl);
935 ctrl->notification_enabled = 1;
936 return 0;
937}
938
939void pcie_shutdown_notification(struct controller *ctrl)
940{
941 if (ctrl->notification_enabled) {
942 pcie_disable_notification(ctrl);
943 pciehp_free_irq(ctrl);
944 ctrl->notification_enabled = 0;
945 }
946}
947
948static inline void dbg_ctrl(struct controller *ctrl)
949{
950 struct pci_dev *pdev = ctrl->pcie->port;
951 u16 reg16;
952
953 ctrl_dbg(ctrl, "Slot Capabilities : 0x%08x\n", ctrl->slot_cap);
954 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, ®16);
955 ctrl_dbg(ctrl, "Slot Status : 0x%04x\n", reg16);
956 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, ®16);
957 ctrl_dbg(ctrl, "Slot Control : 0x%04x\n", reg16);
958}
959
960#define FLAG(x, y) (((x) & (y)) ? '+' : '-')
961
962static inline int pcie_hotplug_depth(struct pci_dev *dev)
963{
964 struct pci_bus *bus = dev->bus;
965 int depth = 0;
966
967 while (bus->parent) {
968 bus = bus->parent;
969 if (bus->self && bus->self->is_hotplug_bridge)
970 depth++;
971 }
972
973 return depth;
974}
975
976struct controller *pcie_init(struct pcie_device *dev)
977{
978 struct controller *ctrl;
979 u32 slot_cap, slot_cap2;
980 u8 poweron;
981 struct pci_dev *pdev = dev->port;
982 struct pci_bus *subordinate = pdev->subordinate;
983
984 ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
985 if (!ctrl)
986 return NULL;
987
988 ctrl->pcie = dev;
989 ctrl->depth = pcie_hotplug_depth(dev->port);
990 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
991
992 if (pdev->hotplug_user_indicators)
993 slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP);
994
995 /*
996 * We assume no Thunderbolt controllers support Command Complete events,
997 * but some controllers falsely claim they do.
998 */
999 if (pdev->is_thunderbolt)
1000 slot_cap |= PCI_EXP_SLTCAP_NCCS;
1001
1002 ctrl->slot_cap = slot_cap;
1003 mutex_init(&ctrl->ctrl_lock);
1004 mutex_init(&ctrl->state_lock);
1005 init_rwsem(&ctrl->reset_lock);
1006 init_waitqueue_head(&ctrl->requester);
1007 init_waitqueue_head(&ctrl->queue);
1008 INIT_DELAYED_WORK(&ctrl->button_work, pciehp_queue_pushbutton_work);
1009 dbg_ctrl(ctrl);
1010
1011 down_read(&pci_bus_sem);
1012 ctrl->state = list_empty(&subordinate->devices) ? OFF_STATE : ON_STATE;
1013 up_read(&pci_bus_sem);
1014
1015 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP2, &slot_cap2);
1016 if (slot_cap2 & PCI_EXP_SLTCAP2_IBPD) {
1017 pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_IBPD_DISABLE,
1018 PCI_EXP_SLTCTL_IBPD_DISABLE);
1019 ctrl->inband_presence_disabled = 1;
1020 }
1021
1022 if (dmi_first_match(inband_presence_disabled_dmi_table))
1023 ctrl->inband_presence_disabled = 1;
1024
1025 /* Clear all remaining event bits in Slot Status register. */
1026 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
1027 PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
1028 PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_CC |
1029 PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC);
1030
1031 ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c IbPresDis%c LLActRep%c%s\n",
1032 FIELD_GET(PCI_EXP_SLTCAP_PSN, slot_cap),
1033 FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
1034 FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
1035 FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
1036 FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
1037 FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
1038 FLAG(slot_cap, PCI_EXP_SLTCAP_HPC),
1039 FLAG(slot_cap, PCI_EXP_SLTCAP_HPS),
1040 FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
1041 FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
1042 FLAG(slot_cap2, PCI_EXP_SLTCAP2_IBPD),
1043 FLAG(pdev->link_active_reporting, true),
1044 pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : "");
1045
1046 /*
1047 * If empty slot's power status is on, turn power off. The IRQ isn't
1048 * requested yet, so avoid triggering a notification with this command.
1049 */
1050 if (POWER_CTRL(ctrl)) {
1051 pciehp_get_power_status(ctrl, &poweron);
1052 if (!pciehp_card_present_or_link_active(ctrl) && poweron) {
1053 pcie_disable_notification(ctrl);
1054 pciehp_power_off_slot(ctrl);
1055 }
1056 }
1057
1058 return ctrl;
1059}
1060
1061void pciehp_release_ctrl(struct controller *ctrl)
1062{
1063 cancel_delayed_work_sync(&ctrl->button_work);
1064 kfree(ctrl);
1065}
1066
1067static void quirk_cmd_compl(struct pci_dev *pdev)
1068{
1069 u32 slot_cap;
1070
1071 if (pci_is_pcie(pdev)) {
1072 pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
1073 if (slot_cap & PCI_EXP_SLTCAP_HPC &&
1074 !(slot_cap & PCI_EXP_SLTCAP_NCCS))
1075 pdev->broken_cmd_compl = 1;
1076 }
1077}
1078DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
1079 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1080DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x010e,
1081 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1082DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0110,
1083 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1084DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
1085 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1086DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401,
1087 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
1088DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_HXT, 0x0401,
1089 PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);