1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * File: portdrv_pci.c
4 * Purpose: PCI Express Port Bus Driver
5 * Author: Tom Nguyen <tom.l.nguyen@intel.com>
6 * Version: v1.0
7 *
8 * Copyright (C) 2004 Intel
9 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
10 */
11
12 #include <linux/pci.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/pm.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/init.h>
18 #include <linux/pcieport_if.h>
19 #include <linux/aer.h>
20 #include <linux/dmi.h>
21 #include <linux/pci-aspm.h>
22
23 #include "../pci.h"
24 #include "portdrv.h"
25
26 /* If this switch is set, PCIe port native services should not be enabled. */
27 bool pcie_ports_disabled;
28
29 /*
30 * If this switch is set, ACPI _OSC will be used to determine whether or not to
31 * enable PCIe port native services.
32 */
33 bool pcie_ports_auto = true;
34
pcie_port_setup(char * str)35 static int __init pcie_port_setup(char *str)
36 {
37 if (!strncmp(str, "compat", 6)) {
38 pcie_ports_disabled = true;
39 } else if (!strncmp(str, "native", 6)) {
40 pcie_ports_disabled = false;
41 pcie_ports_auto = false;
42 } else if (!strncmp(str, "auto", 4)) {
43 pcie_ports_disabled = false;
44 pcie_ports_auto = true;
45 }
46
47 return 1;
48 }
49 __setup("pcie_ports=", pcie_port_setup);
50
51 /* global data */
52
53 /**
54 * pcie_clear_root_pme_status - Clear root port PME interrupt status.
55 * @dev: PCIe root port or event collector.
56 */
pcie_clear_root_pme_status(struct pci_dev * dev)57 void pcie_clear_root_pme_status(struct pci_dev *dev)
58 {
59 pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
60 }
61
pcie_portdrv_restore_config(struct pci_dev * dev)62 static int pcie_portdrv_restore_config(struct pci_dev *dev)
63 {
64 int retval;
65
66 retval = pci_enable_device(dev);
67 if (retval)
68 return retval;
69 pci_set_master(dev);
70 return 0;
71 }
72
73 #ifdef CONFIG_PM
pcie_port_resume_noirq(struct device * dev)74 static int pcie_port_resume_noirq(struct device *dev)
75 {
76 struct pci_dev *pdev = to_pci_dev(dev);
77
78 /*
79 * Some BIOSes forget to clear Root PME Status bits after system wakeup
80 * which breaks ACPI-based runtime wakeup on PCI Express, so clear those
81 * bits now just in case (shouldn't hurt).
82 */
83 if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
84 pcie_clear_root_pme_status(pdev);
85 return 0;
86 }
87
pcie_port_runtime_suspend(struct device * dev)88 static int pcie_port_runtime_suspend(struct device *dev)
89 {
90 return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
91 }
92
pcie_port_runtime_resume(struct device * dev)93 static int pcie_port_runtime_resume(struct device *dev)
94 {
95 return 0;
96 }
97
pcie_port_runtime_idle(struct device * dev)98 static int pcie_port_runtime_idle(struct device *dev)
99 {
100 /*
101 * Assume the PCI core has set bridge_d3 whenever it thinks the port
102 * should be good to go to D3. Everything else, including moving
103 * the port to D3, is handled by the PCI core.
104 */
105 return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
106 }
107
108 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
109 .suspend = pcie_port_device_suspend,
110 .resume = pcie_port_device_resume,
111 .freeze = pcie_port_device_suspend,
112 .thaw = pcie_port_device_resume,
113 .poweroff = pcie_port_device_suspend,
114 .restore = pcie_port_device_resume,
115 .resume_noirq = pcie_port_resume_noirq,
116 .runtime_suspend = pcie_port_runtime_suspend,
117 .runtime_resume = pcie_port_runtime_resume,
118 .runtime_idle = pcie_port_runtime_idle,
119 };
120
121 #define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops)
122
123 #else /* !PM */
124
125 #define PCIE_PORTDRV_PM_OPS NULL
126 #endif /* !PM */
127
128 /*
129 * pcie_portdrv_probe - Probe PCI-Express port devices
130 * @dev: PCI-Express port device being probed
131 *
132 * If detected invokes the pcie_port_device_register() method for
133 * this port device.
134 *
135 */
pcie_portdrv_probe(struct pci_dev * dev,const struct pci_device_id * id)136 static int pcie_portdrv_probe(struct pci_dev *dev,
137 const struct pci_device_id *id)
138 {
139 int status;
140
141 if (!pci_is_pcie(dev) ||
142 ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
143 (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
144 (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
145 return -ENODEV;
146
147 status = pcie_port_device_register(dev);
148 if (status)
149 return status;
150
151 pci_save_state(dev);
152
153 if (pci_bridge_d3_possible(dev)) {
154 /*
155 * Keep the port resumed 100ms to make sure things like
156 * config space accesses from userspace (lspci) will not
157 * cause the port to repeatedly suspend and resume.
158 */
159 pm_runtime_set_autosuspend_delay(&dev->dev, 100);
160 pm_runtime_use_autosuspend(&dev->dev);
161 pm_runtime_mark_last_busy(&dev->dev);
162 pm_runtime_put_autosuspend(&dev->dev);
163 pm_runtime_allow(&dev->dev);
164 }
165
166 return 0;
167 }
168
pcie_portdrv_remove(struct pci_dev * dev)169 static void pcie_portdrv_remove(struct pci_dev *dev)
170 {
171 if (pci_bridge_d3_possible(dev)) {
172 pm_runtime_forbid(&dev->dev);
173 pm_runtime_get_noresume(&dev->dev);
174 pm_runtime_dont_use_autosuspend(&dev->dev);
175 }
176
177 pcie_port_device_remove(dev);
178 }
179
pcie_portdrv_error_detected(struct pci_dev * dev,enum pci_channel_state error)180 static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
181 enum pci_channel_state error)
182 {
183 /* Root Port has no impact. Always recovers. */
184 return PCI_ERS_RESULT_CAN_RECOVER;
185 }
186
pcie_portdrv_mmio_enabled(struct pci_dev * dev)187 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
188 {
189 return PCI_ERS_RESULT_RECOVERED;
190 }
191
pcie_portdrv_slot_reset(struct pci_dev * dev)192 static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
193 {
194 /* If fatal, restore cfg space for possible link reset at upstream */
195 if (dev->error_state == pci_channel_io_frozen) {
196 dev->state_saved = true;
197 pci_restore_state(dev);
198 pcie_portdrv_restore_config(dev);
199 pci_enable_pcie_error_reporting(dev);
200 }
201
202 return PCI_ERS_RESULT_RECOVERED;
203 }
204
resume_iter(struct device * device,void * data)205 static int resume_iter(struct device *device, void *data)
206 {
207 struct pcie_device *pcie_device;
208 struct pcie_port_service_driver *driver;
209
210 if (device->bus == &pcie_port_bus_type && device->driver) {
211 driver = to_service_driver(device->driver);
212 if (driver && driver->error_resume) {
213 pcie_device = to_pcie_device(device);
214
215 /* Forward error message to service drivers */
216 driver->error_resume(pcie_device->port);
217 }
218 }
219
220 return 0;
221 }
222
pcie_portdrv_err_resume(struct pci_dev * dev)223 static void pcie_portdrv_err_resume(struct pci_dev *dev)
224 {
225 device_for_each_child(&dev->dev, NULL, resume_iter);
226 }
227
228 /*
229 * LINUX Device Driver Model
230 */
231 static const struct pci_device_id port_pci_ids[] = { {
232 /* handle any PCI-Express port */
233 PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0),
234 }, { /* end: all zeroes */ }
235 };
236
237 static const struct pci_error_handlers pcie_portdrv_err_handler = {
238 .error_detected = pcie_portdrv_error_detected,
239 .mmio_enabled = pcie_portdrv_mmio_enabled,
240 .slot_reset = pcie_portdrv_slot_reset,
241 .resume = pcie_portdrv_err_resume,
242 };
243
244 static struct pci_driver pcie_portdriver = {
245 .name = "pcieport",
246 .id_table = &port_pci_ids[0],
247
248 .probe = pcie_portdrv_probe,
249 .remove = pcie_portdrv_remove,
250
251 .err_handler = &pcie_portdrv_err_handler,
252
253 .driver.pm = PCIE_PORTDRV_PM_OPS,
254 };
255
dmi_pcie_pme_disable_msi(const struct dmi_system_id * d)256 static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
257 {
258 pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
259 d->ident);
260 pcie_pme_disable_msi();
261 return 0;
262 }
263
264 static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
265 /*
266 * Boxes that should not use MSI for PCIe PME signaling.
267 */
268 {
269 .callback = dmi_pcie_pme_disable_msi,
270 .ident = "MSI Wind U-100",
271 .matches = {
272 DMI_MATCH(DMI_SYS_VENDOR,
273 "MICRO-STAR INTERNATIONAL CO., LTD"),
274 DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
275 },
276 },
277 {}
278 };
279
pcie_portdrv_init(void)280 static int __init pcie_portdrv_init(void)
281 {
282 int retval;
283
284 if (pcie_ports_disabled)
285 return pci_register_driver(&pcie_portdriver);
286
287 dmi_check_system(pcie_portdrv_dmi_table);
288
289 retval = pcie_port_bus_register();
290 if (retval) {
291 printk(KERN_WARNING "PCIE: bus_register error: %d\n", retval);
292 goto out;
293 }
294 retval = pci_register_driver(&pcie_portdriver);
295 if (retval)
296 pcie_port_bus_unregister();
297 out:
298 return retval;
299 }
300 device_initcall(pcie_portdrv_init);
301