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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 	if (type == PCI_EXP_TYPE_RC_EC)
115 		pcie_link_rcec(dev);
116 
117 	status = pcie_port_device_register(dev);
118 	if (status)
119 		return status;
120 
121 	pci_save_state(dev);
122 
123 	dev_pm_set_driver_flags(&dev->dev, DPM_FLAG_NO_DIRECT_COMPLETE |
124 					   DPM_FLAG_SMART_SUSPEND);
125 
126 	if (pci_bridge_d3_possible(dev)) {
127 		/*
128 		 * Keep the port resumed 100ms to make sure things like
129 		 * config space accesses from userspace (lspci) will not
130 		 * cause the port to repeatedly suspend and resume.
131 		 */
132 		pm_runtime_set_autosuspend_delay(&dev->dev, 100);
133 		pm_runtime_use_autosuspend(&dev->dev);
134 		pm_runtime_mark_last_busy(&dev->dev);
135 		pm_runtime_put_autosuspend(&dev->dev);
136 		pm_runtime_allow(&dev->dev);
137 	}
138 
139 	return 0;
140 }
141 
pcie_portdrv_remove(struct pci_dev * dev)142 static void pcie_portdrv_remove(struct pci_dev *dev)
143 {
144 	if (pci_bridge_d3_possible(dev)) {
145 		pm_runtime_forbid(&dev->dev);
146 		pm_runtime_get_noresume(&dev->dev);
147 		pm_runtime_dont_use_autosuspend(&dev->dev);
148 	}
149 
150 	pcie_port_device_remove(dev);
151 }
152 
pcie_portdrv_error_detected(struct pci_dev * dev,pci_channel_state_t error)153 static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
154 					pci_channel_state_t error)
155 {
156 	if (error == pci_channel_io_frozen)
157 		return PCI_ERS_RESULT_NEED_RESET;
158 	return PCI_ERS_RESULT_CAN_RECOVER;
159 }
160 
pcie_portdrv_slot_reset(struct pci_dev * dev)161 static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
162 {
163 	size_t off = offsetof(struct pcie_port_service_driver, slot_reset);
164 	device_for_each_child(&dev->dev, &off, pcie_port_device_iter);
165 
166 	pci_restore_state(dev);
167 	pci_save_state(dev);
168 	return PCI_ERS_RESULT_RECOVERED;
169 }
170 
pcie_portdrv_mmio_enabled(struct pci_dev * dev)171 static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
172 {
173 	return PCI_ERS_RESULT_RECOVERED;
174 }
175 
resume_iter(struct device * device,void * data)176 static int resume_iter(struct device *device, void *data)
177 {
178 	struct pcie_device *pcie_device;
179 	struct pcie_port_service_driver *driver;
180 
181 	if (device->bus == &pcie_port_bus_type && device->driver) {
182 		driver = to_service_driver(device->driver);
183 		if (driver && driver->error_resume) {
184 			pcie_device = to_pcie_device(device);
185 
186 			/* Forward error message to service drivers */
187 			driver->error_resume(pcie_device->port);
188 		}
189 	}
190 
191 	return 0;
192 }
193 
pcie_portdrv_err_resume(struct pci_dev * dev)194 static void pcie_portdrv_err_resume(struct pci_dev *dev)
195 {
196 	device_for_each_child(&dev->dev, NULL, resume_iter);
197 }
198 
199 /*
200  * LINUX Device Driver Model
201  */
202 static const struct pci_device_id port_pci_ids[] = {
203 	/* handle any PCI-Express port */
204 	{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0) },
205 	/* subtractive decode PCI-to-PCI bridge, class type is 060401h */
206 	{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x01), ~0) },
207 	/* handle any Root Complex Event Collector */
208 	{ PCI_DEVICE_CLASS(((PCI_CLASS_SYSTEM_RCEC << 8) | 0x00), ~0) },
209 	{ },
210 };
211 
212 static const struct pci_error_handlers pcie_portdrv_err_handler = {
213 	.error_detected = pcie_portdrv_error_detected,
214 	.slot_reset = pcie_portdrv_slot_reset,
215 	.mmio_enabled = pcie_portdrv_mmio_enabled,
216 	.resume = pcie_portdrv_err_resume,
217 };
218 
219 static struct pci_driver pcie_portdriver = {
220 	.name		= "pcieport",
221 	.id_table	= &port_pci_ids[0],
222 
223 	.probe		= pcie_portdrv_probe,
224 	.remove		= pcie_portdrv_remove,
225 	.shutdown	= pcie_portdrv_remove,
226 
227 	.err_handler	= &pcie_portdrv_err_handler,
228 
229 	.driver.pm	= PCIE_PORTDRV_PM_OPS,
230 };
231 
dmi_pcie_pme_disable_msi(const struct dmi_system_id * d)232 static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
233 {
234 	pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
235 		  d->ident);
236 	pcie_pme_disable_msi();
237 	return 0;
238 }
239 
240 static const struct dmi_system_id pcie_portdrv_dmi_table[] __initconst = {
241 	/*
242 	 * Boxes that should not use MSI for PCIe PME signaling.
243 	 */
244 	{
245 	 .callback = dmi_pcie_pme_disable_msi,
246 	 .ident = "MSI Wind U-100",
247 	 .matches = {
248 		     DMI_MATCH(DMI_SYS_VENDOR,
249 				"MICRO-STAR INTERNATIONAL CO., LTD"),
250 		     DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
251 		     },
252 	 },
253 	 {}
254 };
255 
pcie_init_services(void)256 static void __init pcie_init_services(void)
257 {
258 	pcie_aer_init();
259 	pcie_pme_init();
260 	pcie_dpc_init();
261 	pcie_hp_init();
262 }
263 
pcie_portdrv_init(void)264 static int __init pcie_portdrv_init(void)
265 {
266 	if (pcie_ports_disabled)
267 		return -EACCES;
268 
269 	pcie_init_services();
270 	dmi_check_system(pcie_portdrv_dmi_table);
271 
272 	return pci_register_driver(&pcie_portdriver);
273 }
274 device_initcall(pcie_portdrv_init);
275