1// SPDX-License-Identifier: GPL-2.0
2
3#define pr_fmt(fmt) "PCI: " fmt
4
5#include <linux/pci.h>
6#include <linux/acpi.h>
7#include <linux/init.h>
8#include <linux/irq.h>
9#include <linux/dmi.h>
10#include <linux/slab.h>
11#include <linux/pci-acpi.h>
12#include <asm/numa.h>
13#include <asm/pci_x86.h>
14
15struct pci_root_info {
16 struct acpi_pci_root_info common;
17 struct pci_sysdata sd;
18#ifdef CONFIG_PCI_MMCONFIG
19 bool mcfg_added;
20 u8 start_bus;
21 u8 end_bus;
22#endif
23};
24
25bool pci_use_e820 = true;
26static bool pci_use_crs = true;
27static bool pci_ignore_seg;
28
29static int __init set_use_crs(const struct dmi_system_id *id)
30{
31 pci_use_crs = true;
32 return 0;
33}
34
35static int __init set_nouse_crs(const struct dmi_system_id *id)
36{
37 pci_use_crs = false;
38 return 0;
39}
40
41static int __init set_ignore_seg(const struct dmi_system_id *id)
42{
43 pr_info("%s detected: ignoring ACPI _SEG\n", id->ident);
44 pci_ignore_seg = true;
45 return 0;
46}
47
48static int __init set_no_e820(const struct dmi_system_id *id)
49{
50 pr_info("%s detected: not clipping E820 regions from _CRS\n",
51 id->ident);
52 pci_use_e820 = false;
53 return 0;
54}
55
56static const struct dmi_system_id pci_crs_quirks[] __initconst = {
57 /* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */
58 {
59 .callback = set_use_crs,
60 .ident = "IBM System x3800",
61 .matches = {
62 DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
63 DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
64 },
65 },
66 /* https://bugzilla.kernel.org/show_bug.cgi?id=16007 */
67 /* 2006 AMD HT/VIA system with two host bridges */
68 {
69 .callback = set_use_crs,
70 .ident = "ASRock ALiveSATA2-GLAN",
71 .matches = {
72 DMI_MATCH(DMI_PRODUCT_NAME, "ALiveSATA2-GLAN"),
73 },
74 },
75 /* https://bugzilla.kernel.org/show_bug.cgi?id=30552 */
76 /* 2006 AMD HT/VIA system with two host bridges */
77 {
78 .callback = set_use_crs,
79 .ident = "ASUS M2V-MX SE",
80 .matches = {
81 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
82 DMI_MATCH(DMI_BOARD_NAME, "M2V-MX SE"),
83 DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
84 },
85 },
86 /* https://bugzilla.kernel.org/show_bug.cgi?id=42619 */
87 {
88 .callback = set_use_crs,
89 .ident = "MSI MS-7253",
90 .matches = {
91 DMI_MATCH(DMI_BOARD_VENDOR, "MICRO-STAR INTERNATIONAL CO., LTD"),
92 DMI_MATCH(DMI_BOARD_NAME, "MS-7253"),
93 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies, LTD"),
94 },
95 },
96 /* https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/931368 */
97 /* https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1033299 */
98 {
99 .callback = set_use_crs,
100 .ident = "Foxconn K8M890-8237A",
101 .matches = {
102 DMI_MATCH(DMI_BOARD_VENDOR, "Foxconn"),
103 DMI_MATCH(DMI_BOARD_NAME, "K8M890-8237A"),
104 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies, LTD"),
105 },
106 },
107
108 /* Now for the blacklist.. */
109
110 /* https://bugzilla.redhat.com/show_bug.cgi?id=769657 */
111 {
112 .callback = set_nouse_crs,
113 .ident = "Dell Studio 1557",
114 .matches = {
115 DMI_MATCH(DMI_BOARD_VENDOR, "Dell Inc."),
116 DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1557"),
117 DMI_MATCH(DMI_BIOS_VERSION, "A09"),
118 },
119 },
120 /* https://bugzilla.redhat.com/show_bug.cgi?id=769657 */
121 {
122 .callback = set_nouse_crs,
123 .ident = "Thinkpad SL510",
124 .matches = {
125 DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"),
126 DMI_MATCH(DMI_BOARD_NAME, "2847DFG"),
127 DMI_MATCH(DMI_BIOS_VERSION, "6JET85WW (1.43 )"),
128 },
129 },
130 /* https://bugzilla.kernel.org/show_bug.cgi?id=42606 */
131 {
132 .callback = set_nouse_crs,
133 .ident = "Supermicro X8DTH",
134 .matches = {
135 DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
136 DMI_MATCH(DMI_PRODUCT_NAME, "X8DTH-i/6/iF/6F"),
137 DMI_MATCH(DMI_BIOS_VERSION, "2.0a"),
138 },
139 },
140
141 /* https://bugzilla.kernel.org/show_bug.cgi?id=15362 */
142 {
143 .callback = set_ignore_seg,
144 .ident = "HP xw9300",
145 .matches = {
146 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
147 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"),
148 },
149 },
150
151 /*
152 * Many Lenovo models with "IIL" in their DMI_PRODUCT_VERSION have
153 * an E820 reserved region that covers the entire 32-bit host
154 * bridge memory window from _CRS. Using the E820 region to clip
155 * _CRS means no space is available for hot-added or uninitialized
156 * PCI devices. This typically breaks I2C controllers for touchpads
157 * and hot-added Thunderbolt devices. See the commit log for
158 * models known to require this quirk and related bug reports.
159 */
160 {
161 .callback = set_no_e820,
162 .ident = "Lenovo *IIL* product version",
163 .matches = {
164 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
165 DMI_MATCH(DMI_PRODUCT_VERSION, "IIL"),
166 },
167 },
168
169 /*
170 * The Acer Spin 5 (SP513-54N) has the same E820 reservation covering
171 * the entire _CRS 32-bit window issue as the Lenovo *IIL* models.
172 * See https://bugs.launchpad.net/bugs/1884232
173 */
174 {
175 .callback = set_no_e820,
176 .ident = "Acer Spin 5 (SP513-54N)",
177 .matches = {
178 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
179 DMI_MATCH(DMI_PRODUCT_NAME, "Spin SP513-54N"),
180 },
181 },
182
183 /*
184 * Clevo X170KM-G barebones have the same E820 reservation covering
185 * the entire _CRS 32-bit window issue as the Lenovo *IIL* models.
186 * See https://bugzilla.kernel.org/show_bug.cgi?id=214259
187 */
188 {
189 .callback = set_no_e820,
190 .ident = "Clevo X170KM-G Barebone",
191 .matches = {
192 DMI_MATCH(DMI_BOARD_NAME, "X170KM-G"),
193 },
194 },
195 {}
196};
197
198void __init pci_acpi_crs_quirks(void)
199{
200 int year = dmi_get_bios_year();
201
202 if (year >= 0 && year < 2008 && iomem_resource.end <= 0xffffffff)
203 pci_use_crs = false;
204
205 /*
206 * Some firmware includes unusable space (host bridge registers,
207 * hidden PCI device BARs, etc) in PCI host bridge _CRS. This is a
208 * firmware defect, and 4dc2287c1805 ("x86: avoid E820 regions when
209 * allocating address space") has clipped out the unusable space in
210 * the past.
211 *
212 * But other firmware supplies E820 reserved regions that cover
213 * entire _CRS windows, so clipping throws away the entire window,
214 * leaving none for hot-added or uninitialized devices. These E820
215 * entries are probably *not* a firmware defect, so disable the
216 * clipping by default for post-2022 machines.
217 *
218 * We already have quirks to disable clipping for pre-2023
219 * machines, and we'll likely need quirks to *enable* clipping for
220 * post-2022 machines that incorrectly include unusable space in
221 * _CRS.
222 */
223 if (year >= 2023)
224 pci_use_e820 = false;
225
226 dmi_check_system(list: pci_crs_quirks);
227
228 /*
229 * If the user specifies "pci=use_crs" or "pci=nocrs" explicitly, that
230 * takes precedence over anything we figured out above.
231 */
232 if (pci_probe & PCI_ROOT_NO_CRS)
233 pci_use_crs = false;
234 else if (pci_probe & PCI_USE__CRS)
235 pci_use_crs = true;
236
237 pr_info("%s host bridge windows from ACPI; if necessary, use \"pci=%s\" and report a bug\n",
238 pci_use_crs ? "Using" : "Ignoring",
239 pci_use_crs ? "nocrs" : "use_crs");
240
241 /* "pci=use_e820"/"pci=no_e820" on the kernel cmdline takes precedence */
242 if (pci_probe & PCI_NO_E820)
243 pci_use_e820 = false;
244 else if (pci_probe & PCI_USE_E820)
245 pci_use_e820 = true;
246
247 pr_info("%s E820 reservations for host bridge windows\n",
248 pci_use_e820 ? "Using" : "Ignoring");
249 if (pci_probe & (PCI_NO_E820 | PCI_USE_E820))
250 pr_info("Please notify linux-pci@vger.kernel.org so future kernels can do this automatically\n");
251}
252
253/*
254 * Check if pdev is part of a PCIe switch that is directly below the
255 * specified bridge.
256 */
257static bool pcie_switch_directly_under(struct pci_dev *bridge,
258 struct pci_dev *pdev)
259{
260 struct pci_dev *parent = pci_upstream_bridge(dev: pdev);
261
262 /* If the device doesn't have a parent, it's not under anything */
263 if (!parent)
264 return false;
265
266 /*
267 * If the device has a PCIe type, check if it is below the
268 * corresponding PCIe switch components (if applicable). Then check
269 * if its upstream port is directly beneath the specified bridge.
270 */
271 switch (pci_pcie_type(dev: pdev)) {
272 case PCI_EXP_TYPE_UPSTREAM:
273 return parent == bridge;
274
275 case PCI_EXP_TYPE_DOWNSTREAM:
276 if (pci_pcie_type(dev: parent) != PCI_EXP_TYPE_UPSTREAM)
277 return false;
278 parent = pci_upstream_bridge(dev: parent);
279 return parent == bridge;
280
281 case PCI_EXP_TYPE_ENDPOINT:
282 if (pci_pcie_type(dev: parent) != PCI_EXP_TYPE_DOWNSTREAM)
283 return false;
284 parent = pci_upstream_bridge(dev: parent);
285 if (!parent || pci_pcie_type(dev: parent) != PCI_EXP_TYPE_UPSTREAM)
286 return false;
287 parent = pci_upstream_bridge(dev: parent);
288 return parent == bridge;
289 }
290
291 return false;
292}
293
294static bool pcie_has_usb4_host_interface(struct pci_dev *pdev)
295{
296 struct fwnode_handle *fwnode;
297
298 /*
299 * For USB4, the tunneled PCIe Root or Downstream Ports are marked
300 * with the "usb4-host-interface" ACPI property, so we look for
301 * that first. This should cover most cases.
302 */
303 fwnode = fwnode_find_reference(dev_fwnode(&pdev->dev),
304 name: "usb4-host-interface", index: 0);
305 if (!IS_ERR(ptr: fwnode)) {
306 fwnode_handle_put(fwnode);
307 return true;
308 }
309
310 /*
311 * Any integrated Thunderbolt 3/4 PCIe Root Ports from Intel
312 * before Alder Lake do not have the "usb4-host-interface"
313 * property so we use their PCI IDs instead. All these are
314 * tunneled. This list is not expected to grow.
315 */
316 if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
317 switch (pdev->device) {
318 /* Ice Lake Thunderbolt 3 PCIe Root Ports */
319 case 0x8a1d:
320 case 0x8a1f:
321 case 0x8a21:
322 case 0x8a23:
323 /* Tiger Lake-LP Thunderbolt 4 PCIe Root Ports */
324 case 0x9a23:
325 case 0x9a25:
326 case 0x9a27:
327 case 0x9a29:
328 /* Tiger Lake-H Thunderbolt 4 PCIe Root Ports */
329 case 0x9a2b:
330 case 0x9a2d:
331 case 0x9a2f:
332 case 0x9a31:
333 return true;
334 }
335 }
336
337 return false;
338}
339
340bool arch_pci_dev_is_removable(struct pci_dev *pdev)
341{
342 struct pci_dev *parent, *root;
343
344 /* pdev without a parent or Root Port is never tunneled */
345 parent = pci_upstream_bridge(dev: pdev);
346 if (!parent)
347 return false;
348 root = pcie_find_root_port(dev: pdev);
349 if (!root)
350 return false;
351
352 /* Internal PCIe devices are not tunneled */
353 if (!root->external_facing)
354 return false;
355
356 /* Anything directly behind a "usb4-host-interface" is tunneled */
357 if (pcie_has_usb4_host_interface(pdev: parent))
358 return true;
359
360 /*
361 * Check if this is a discrete Thunderbolt/USB4 controller that is
362 * directly behind the non-USB4 PCIe Root Port marked as
363 * "ExternalFacingPort". Those are not behind a PCIe tunnel.
364 */
365 if (pcie_switch_directly_under(bridge: root, pdev))
366 return false;
367
368 /* PCIe devices after the discrete chip are tunneled */
369 return true;
370}
371
372#ifdef CONFIG_PCI_MMCONFIG
373static int check_segment(u16 seg, struct device *dev, char *estr)
374{
375 if (seg) {
376 dev_err(dev, "%s can't access configuration space under this host bridge\n",
377 estr);
378 return -EIO;
379 }
380
381 /*
382 * Failure in adding MMCFG information is not fatal,
383 * just can't access extended configuration space of
384 * devices under this host bridge.
385 */
386 dev_warn(dev, "%s can't access extended configuration space under this bridge\n",
387 estr);
388
389 return 0;
390}
391
392static int setup_mcfg_map(struct acpi_pci_root_info *ci)
393{
394 int result, seg;
395 struct pci_root_info *info;
396 struct acpi_pci_root *root = ci->root;
397 struct device *dev = &ci->bridge->dev;
398
399 info = container_of(ci, struct pci_root_info, common);
400 info->start_bus = (u8)root->secondary.start;
401 info->end_bus = (u8)root->secondary.end;
402 info->mcfg_added = false;
403 seg = info->sd.domain;
404
405 dev_dbg(dev, "%s(%04x %pR ECAM %pa)\n", __func__, seg,
406 &root->secondary, &root->mcfg_addr);
407
408 /* return success if MMCFG is not in use */
409 if (raw_pci_ext_ops && raw_pci_ext_ops != &pci_mmcfg)
410 return 0;
411
412 if (!(pci_probe & PCI_PROBE_MMCONF))
413 return check_segment(seg, dev, estr: "MMCONFIG is disabled,");
414
415 result = pci_mmconfig_insert(dev, seg, start: info->start_bus, end: info->end_bus,
416 addr: root->mcfg_addr);
417 if (result == 0) {
418 /* enable MMCFG if it hasn't been enabled yet */
419 if (raw_pci_ext_ops == NULL)
420 raw_pci_ext_ops = &pci_mmcfg;
421 info->mcfg_added = true;
422 } else if (result != -EEXIST)
423 return check_segment(seg, dev,
424 estr: "fail to add MMCONFIG information,");
425
426 return 0;
427}
428
429static void teardown_mcfg_map(struct acpi_pci_root_info *ci)
430{
431 struct pci_root_info *info;
432
433 info = container_of(ci, struct pci_root_info, common);
434 if (info->mcfg_added) {
435 pci_mmconfig_delete(seg: info->sd.domain,
436 start: info->start_bus, end: info->end_bus);
437 info->mcfg_added = false;
438 }
439}
440#else
441static int setup_mcfg_map(struct acpi_pci_root_info *ci)
442{
443 return 0;
444}
445
446static void teardown_mcfg_map(struct acpi_pci_root_info *ci)
447{
448}
449#endif
450
451static int pci_acpi_root_get_node(struct acpi_pci_root *root)
452{
453 int busnum = root->secondary.start;
454 struct acpi_device *device = root->device;
455 int node = acpi_get_node(handle: device->handle);
456
457 if (node == NUMA_NO_NODE) {
458 node = x86_pci_root_bus_node(bus: busnum);
459 if (node != 0 && node != NUMA_NO_NODE)
460 dev_info(&device->dev, FW_BUG "no _PXM; falling back to node %d from hardware (may be inconsistent with ACPI node numbers)\n",
461 node);
462 }
463 if (node != NUMA_NO_NODE && !node_online(node))
464 node = NUMA_NO_NODE;
465
466 return node;
467}
468
469static int pci_acpi_root_init_info(struct acpi_pci_root_info *ci)
470{
471 return setup_mcfg_map(ci);
472}
473
474static void pci_acpi_root_release_info(struct acpi_pci_root_info *ci)
475{
476 teardown_mcfg_map(ci);
477 kfree(container_of(ci, struct pci_root_info, common));
478}
479
480/*
481 * An IO port or MMIO resource assigned to a PCI host bridge may be
482 * consumed by the host bridge itself or available to its child
483 * bus/devices. The ACPI specification defines a bit (Producer/Consumer)
484 * to tell whether the resource is consumed by the host bridge itself,
485 * but firmware hasn't used that bit consistently, so we can't rely on it.
486 *
487 * On x86 and IA64 platforms, all IO port and MMIO resources are assumed
488 * to be available to child bus/devices except one special case:
489 * IO port [0xCF8-0xCFF] is consumed by the host bridge itself
490 * to access PCI configuration space.
491 *
492 * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
493 */
494static bool resource_is_pcicfg_ioport(struct resource *res)
495{
496 return (res->flags & IORESOURCE_IO) &&
497 res->start == 0xCF8 && res->end == 0xCFF;
498}
499
500static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
501{
502 struct acpi_device *device = ci->bridge;
503 int busnum = ci->root->secondary.start;
504 struct resource_entry *entry, *tmp;
505 int status;
506
507 status = acpi_pci_probe_root_resources(info: ci);
508
509 if (pci_use_crs) {
510 resource_list_for_each_entry_safe(entry, tmp, &ci->resources)
511 if (resource_is_pcicfg_ioport(res: entry->res))
512 resource_list_destroy_entry(entry);
513 return status;
514 }
515
516 resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
517 dev_printk(KERN_DEBUG, &device->dev,
518 "host bridge window %pR (ignored)\n", entry->res);
519 resource_list_destroy_entry(entry);
520 }
521 x86_pci_root_bus_resources(bus: busnum, resources: &ci->resources);
522
523 return 0;
524}
525
526static struct acpi_pci_root_ops acpi_pci_root_ops = {
527 .pci_ops = &pci_root_ops,
528 .init_info = pci_acpi_root_init_info,
529 .release_info = pci_acpi_root_release_info,
530 .prepare_resources = pci_acpi_root_prepare_resources,
531};
532
533struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
534{
535 int domain = root->segment;
536 int busnum = root->secondary.start;
537 int node = pci_acpi_root_get_node(root);
538 struct pci_bus *bus;
539
540 if (pci_ignore_seg)
541 root->segment = domain = 0;
542
543 if (domain && !pci_domains_supported) {
544 pr_warn("pci_bus %04x:%02x: ignored (multiple domains not supported)\n",
545 domain, busnum);
546 return NULL;
547 }
548
549 bus = pci_find_bus(domain, busnr: busnum);
550 if (bus) {
551 /*
552 * If the desired bus has been scanned already, replace
553 * its bus->sysdata.
554 */
555 struct pci_sysdata sd = {
556 .domain = domain,
557 .node = node,
558 .companion = root->device
559 };
560
561 memcpy(bus->sysdata, &sd, sizeof(sd));
562 } else {
563 struct pci_root_info *info;
564
565 info = kzalloc(sizeof(*info), GFP_KERNEL);
566 if (!info)
567 dev_err(&root->device->dev,
568 "pci_bus %04x:%02x: ignored (out of memory)\n",
569 domain, busnum);
570 else {
571 info->sd.domain = domain;
572 info->sd.node = node;
573 info->sd.companion = root->device;
574 bus = acpi_pci_root_create(root, ops: &acpi_pci_root_ops,
575 info: &info->common, sd: &info->sd);
576 }
577 }
578
579 /* After the PCI-E bus has been walked and all devices discovered,
580 * configure any settings of the fabric that might be necessary.
581 */
582 if (bus) {
583 struct pci_bus *child;
584 list_for_each_entry(child, &bus->children, node)
585 pcie_bus_configure_settings(bus: child);
586 }
587
588 return bus;
589}
590
591int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
592{
593 /*
594 * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
595 * here, pci_create_root_bus() has been called by someone else and
596 * sysdata is likely to be different from what we expect. Let it go in
597 * that case.
598 */
599 if (!bridge->dev.parent) {
600 struct pci_sysdata *sd = bridge->bus->sysdata;
601 ACPI_COMPANION_SET(&bridge->dev, sd->companion);
602 }
603 return 0;
604}
605
606int __init pci_acpi_init(void)
607{
608 struct pci_dev *dev = NULL;
609
610 if (acpi_noirq)
611 return -ENODEV;
612
613 pr_info("Using ACPI for IRQ routing\n");
614 acpi_irq_penalty_init();
615 pcibios_enable_irq = acpi_pci_irq_enable;
616 pcibios_disable_irq = acpi_pci_irq_disable;
617 x86_init.pci.init_irq = x86_init_noop;
618
619 if (pci_routeirq) {
620 /*
621 * PCI IRQ routing is set up by pci_enable_device(), but we
622 * also do it here in case there are still broken drivers that
623 * don't use pci_enable_device().
624 */
625 pr_info("Routing PCI interrupts for all devices because \"pci=routeirq\" specified\n");
626 for_each_pci_dev(dev)
627 acpi_pci_irq_enable(dev);
628 }
629
630 return 0;
631}
632

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source code of linux/arch/x86/pci/acpi.c