1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Purpose: PCI Express Port Bus Driver
4 * Author: Tom Nguyen <tom.l.nguyen@intel.com>
5 *
6 * Copyright (C) 2004 Intel
7 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
8 */
9
10 #include <linux/pci.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/pm.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/init.h>
16 #include <linux/aer.h>
17 #include <linux/dmi.h>
18
19 #include "../pci.h"
20 #include "portdrv.h"
21
22 /* If this switch is set, PCIe port native services should not be enabled. */
23 bool pcie_ports_disabled;
24
25 /*
26 * If the user specified "pcie_ports=native", use the PCIe services regardless
27 * of whether the platform has given us permission. On ACPI systems, this
28 * means we ignore _OSC.
29 */
30 bool pcie_ports_native;
31
32 /*
33 * If the user specified "pcie_ports=dpc-native", use the Linux DPC PCIe
34 * service even if the platform hasn't given us permission.
35 */
36 bool pcie_ports_dpc_native;
37
pcie_port_setup(char * str)38 static int __init pcie_port_setup(char *str)
39 {
40 if (!strncmp(str, "compat", 6))
41 pcie_ports_disabled = true;
42 else if (!strncmp(str, "native", 6))
43 pcie_ports_native = true;
44 else if (!strncmp(str, "dpc-native", 10))
45 pcie_ports_dpc_native = true;
46
47 return 1;
48 }
49 __setup("pcie_ports=", pcie_port_setup);
50
51 /* global data */
52
53 #ifdef CONFIG_PM
pcie_port_runtime_suspend(struct device * dev)54 static int pcie_port_runtime_suspend(struct device *dev)
55 {
56 if (!to_pci_dev(dev)->bridge_d3)
57 return -EBUSY;
58
59 return pcie_port_device_runtime_suspend(dev);
60 }
61
pcie_port_runtime_idle(struct device * dev)62 static int pcie_port_runtime_idle(struct device *dev)
63 {
64 /*
65 * Assume the PCI core has set bridge_d3 whenever it thinks the port
66 * should be good to go to D3. Everything else, including moving
67 * the port to D3, is handled by the PCI core.
68 */
69 return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
70 }
71
72 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
73 .suspend = pcie_port_device_suspend,
74 .resume_noirq = pcie_port_device_resume_noirq,
75 .resume = pcie_port_device_resume,
76 .freeze = pcie_port_device_suspend,
77 .thaw = pcie_port_device_resume,
78 .poweroff = pcie_port_device_suspend,
79 .restore_noirq = pcie_port_device_resume_noirq,
80 .restore = pcie_port_device_resume,
81 .runtime_suspend = pcie_port_runtime_suspend,
82 .runtime_resume = pcie_port_device_runtime_resume,
83 .runtime_idle = pcie_port_runtime_idle,
84 };
85
86 #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops)
87
88 #else /* !PM */
89
90 #define PCIE_PORTDRV_PM_OPS NULL
91 #endif /* !PM */
92
93 /*
94 * pcie_portdrv_probe - Probe PCI-Express port devices
95 * @dev: PCI-Express port device being probed
96 *
97 * If detected invokes the pcie_port_device_register() method for
98 * this port device.
99 *
100 */
pcie_portdrv_probe(struct pci_dev * dev,const struct pci_device_id * id)101 static int pcie_portdrv_probe(struct pci_dev *dev,
102 const struct pci_device_id *id)
103 {
104 int type = pci_pcie_type(dev);
105 int status;
106
107 if (!pci_is_pcie(dev) ||
108 ((type != PCI_EXP_TYPE_ROOT_PORT) &&
109 (type != PCI_EXP_TYPE_UPSTREAM) &&
110 (type != PCI_EXP_TYPE_DOWNSTREAM) &&
111 (type != PCI_EXP_TYPE_RC_EC)))
112 return -ENODEV;
113
114 status = pcie_port_device_register(dev);
115 if (status)
116 return status;
117
118 pci_save_state(dev);
119
120 dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE |
121 DPM_FLAG_SMART_SUSPEND);
122
123 if (pci_bridge_d3_possible(dev)) {
124 /*
125 * Keep the port resumed 100ms to make sure things like
126 * config space accesses from userspace (lspci) will not
127 * cause the port to repeatedly suspend and resume.
128 */
129 pm_runtime_set_autosuspend_delay(&dev->dev, 100);
130 pm_runtime_use_autosuspend(&dev->dev);
131 pm_runtime_mark_last_busy(&dev->dev);
132 pm_runtime_put_autosuspend(&dev->dev);
133 pm_runtime_allow(&dev->dev);
134 }
135
136 return 0;
137 }
138
pcie_portdrv_remove(struct pci_dev * dev)139 static void pcie_portdrv_remove(struct pci_dev *dev)
140 {
141 if (pci_bridge_d3_possible(dev)) {
142 pm_runtime_forbid(&dev->dev);
143 pm_runtime_get_noresume(&dev->dev);
144 pm_runtime_dont_use_autosuspend(&dev->dev);
145 }
146
147 pcie_port_device_remove(dev);
148 }
149
pcie_portdrv_error_detected(struct pci_dev * dev,pci_channel_state_t error)150 static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
151 pci_channel_state_t error)
152 {
153 /* Root Port has no impact. Always recovers. */
154 return PCI_ERS_RESULT_CAN_RECOVER;
155 }
156
pcie_portdrv_slot_reset(struct pci_dev * dev)157 static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
158 {
159 pci_restore_state(dev);
160 pci_save_state(dev);
161 return PCI_ERS_RESULT_RECOVERED;
162 }
163
pcie_portdrv_mmio_enabled(struct pci_dev * dev)164 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
165 {
166 return PCI_ERS_RESULT_RECOVERED;
167 }
168
resume_iter(struct device * device,void * data)169 static int resume_iter(struct device *device, void *data)
170 {
171 struct pcie_device *pcie_device;
172 struct pcie_port_service_driver *driver;
173
174 if (device->bus == &pcie_port_bus_type && device->driver) {
175 driver = to_service_driver(device->driver);
176 if (driver && driver->error_resume) {
177 pcie_device = to_pcie_device(device);
178
179 /* Forward error message to service drivers */
180 driver->error_resume(pcie_device->port);
181 }
182 }
183
184 return 0;
185 }
186
pcie_portdrv_err_resume(struct pci_dev * dev)187 static void pcie_portdrv_err_resume(struct pci_dev *dev)
188 {
189 device_for_each_child(&dev->dev, NULL, resume_iter);
190 }
191
192 /*
193 * LINUX Device Driver Model
194 */
195 static const struct pci_device_id port_pci_ids[] = {
196 /* handle any PCI-Express port */
197 { PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0) },
198 /* subtractive decode PCI-to-PCI bridge, class type is 060401h */
199 { PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x01), ~0) },
200 /* handle any Root Complex Event Collector */
201 { PCI_DEVICE_CLASS(((PCI_CLASS_SYSTEM_RCEC << 8) | 0x00), ~0) },
202 { },
203 };
204
205 static const struct pci_error_handlers pcie_portdrv_err_handler = {
206 .error_detected = pcie_portdrv_error_detected,
207 .slot_reset = pcie_portdrv_slot_reset,
208 .mmio_enabled = pcie_portdrv_mmio_enabled,
209 .resume = pcie_portdrv_err_resume,
210 };
211
212 static struct pci_driver pcie_portdriver = {
213 .name = "pcieport",
214 .id_table = &port_pci_ids[0],
215
216 .probe = pcie_portdrv_probe,
217 .remove = pcie_portdrv_remove,
218 .shutdown = pcie_portdrv_remove,
219
220 .err_handler = &pcie_portdrv_err_handler,
221
222 .driver.pm = PCIE_PORTDRV_PM_OPS,
223 };
224
dmi_pcie_pme_disable_msi(const struct dmi_system_id * d)225 static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
226 {
227 pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
228 d->ident);
229 pcie_pme_disable_msi();
230 return 0;
231 }
232
233 static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
234 /*
235 * Boxes that should not use MSI for PCIe PME signaling.
236 */
237 {
238 .callback = dmi_pcie_pme_disable_msi,
239 .ident = "MSI Wind U-100",
240 .matches = {
241 DMI_MATCH(DMI_SYS_VENDOR,
242 "MICRO-STAR INTERNATIONAL CO., LTD"),
243 DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
244 },
245 },
246 {}
247 };
248
pcie_init_services(void)249 static void __init pcie_init_services(void)
250 {
251 pcie_aer_init();
252 pcie_pme_init();
253 pcie_dpc_init();
254 pcie_hp_init();
255 }
256
pcie_portdrv_init(void)257 static int __init pcie_portdrv_init(void)
258 {
259 if (pcie_ports_disabled)
260 return -EACCES;
261
262 pcie_init_services();
263 dmi_check_system(pcie_portdrv_dmi_table);
264
265 return pci_register_driver(&pcie_portdriver);
266 }
267 device_initcall(pcie_portdrv_init);
268