1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * PCI Express Hot Plug Controller 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 * Authors:
15 * Dan Zink <dan.zink@compaq.com>
16 * Greg Kroah-Hartman <greg@kroah.com>
17 * Dely Sy <dely.l.sy@intel.com>"
18 */
19
20#define pr_fmt(fmt) "pciehp: " fmt
21#define dev_fmt pr_fmt
22
23#include <linux/bitfield.h>
24#include <linux/moduleparam.h>
25#include <linux/kernel.h>
26#include <linux/slab.h>
27#include <linux/types.h>
28#include <linux/pci.h>
29#include "pciehp.h"
30
31#include "../pci.h"
32
33/* Global variables */
34bool pciehp_poll_mode;
35int pciehp_poll_time;
36
37/*
38 * not really modular, but the easiest way to keep compat with existing
39 * bootargs behaviour is to continue using module_param here.
40 */
41module_param(pciehp_poll_mode, bool, 0644);
42module_param(pciehp_poll_time, int, 0644);
43MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
44MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
45
46static int set_attention_status(struct hotplug_slot *slot, u8 value);
47static int get_power_status(struct hotplug_slot *slot, u8 *value);
48static int get_latch_status(struct hotplug_slot *slot, u8 *value);
49static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
50
51static int init_slot(struct controller *ctrl)
52{
53 struct hotplug_slot_ops *ops;
54 char name[SLOT_NAME_SIZE];
55 int retval;
56
57 /* Setup hotplug slot ops */
58 ops = kzalloc(sizeof(*ops), GFP_KERNEL);
59 if (!ops)
60 return -ENOMEM;
61
62 ops->enable_slot = pciehp_sysfs_enable_slot;
63 ops->disable_slot = pciehp_sysfs_disable_slot;
64 ops->get_power_status = get_power_status;
65 ops->get_adapter_status = get_adapter_status;
66 ops->reset_slot = pciehp_reset_slot;
67 if (MRL_SENS(ctrl))
68 ops->get_latch_status = get_latch_status;
69 if (ATTN_LED(ctrl)) {
70 ops->get_attention_status = pciehp_get_attention_status;
71 ops->set_attention_status = set_attention_status;
72 } else if (ctrl->pcie->port->hotplug_user_indicators) {
73 ops->get_attention_status = pciehp_get_raw_indicator_status;
74 ops->set_attention_status = pciehp_set_raw_indicator_status;
75 }
76
77 /* register this slot with the hotplug pci core */
78 ctrl->hotplug_slot.ops = ops;
79 snprintf(buf: name, SLOT_NAME_SIZE, fmt: "%u", PSN(ctrl));
80
81 retval = pci_hp_initialize(&ctrl->hotplug_slot,
82 ctrl->pcie->port->subordinate, 0, name);
83 if (retval) {
84 ctrl_err(ctrl, "pci_hp_initialize failed: error %d\n", retval);
85 kfree(objp: ops);
86 }
87 return retval;
88}
89
90static void cleanup_slot(struct controller *ctrl)
91{
92 struct hotplug_slot *hotplug_slot = &ctrl->hotplug_slot;
93
94 pci_hp_destroy(slot: hotplug_slot);
95 kfree(objp: hotplug_slot->ops);
96}
97
98/*
99 * set_attention_status - Turns the Attention Indicator on, off or blinking
100 */
101static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
102{
103 struct controller *ctrl = to_ctrl(hotplug_slot);
104 struct pci_dev *pdev = ctrl->pcie->port;
105
106 if (status)
107 status = FIELD_PREP(PCI_EXP_SLTCTL_AIC, status);
108 else
109 status = PCI_EXP_SLTCTL_ATTN_IND_OFF;
110
111 pci_config_pm_runtime_get(dev: pdev);
112 pciehp_set_indicators(ctrl, INDICATOR_NOOP, attn: status);
113 pci_config_pm_runtime_put(dev: pdev);
114 return 0;
115}
116
117static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
118{
119 struct controller *ctrl = to_ctrl(hotplug_slot);
120 struct pci_dev *pdev = ctrl->pcie->port;
121
122 pci_config_pm_runtime_get(dev: pdev);
123 pciehp_get_power_status(ctrl, status: value);
124 pci_config_pm_runtime_put(dev: pdev);
125 return 0;
126}
127
128static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
129{
130 struct controller *ctrl = to_ctrl(hotplug_slot);
131 struct pci_dev *pdev = ctrl->pcie->port;
132
133 pci_config_pm_runtime_get(dev: pdev);
134 pciehp_get_latch_status(ctrl, status: value);
135 pci_config_pm_runtime_put(dev: pdev);
136 return 0;
137}
138
139static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
140{
141 struct controller *ctrl = to_ctrl(hotplug_slot);
142 struct pci_dev *pdev = ctrl->pcie->port;
143 int ret;
144
145 pci_config_pm_runtime_get(dev: pdev);
146 ret = pciehp_card_present_or_link_active(ctrl);
147 pci_config_pm_runtime_put(dev: pdev);
148 if (ret < 0)
149 return ret;
150
151 *value = ret;
152 return 0;
153}
154
155/**
156 * pciehp_check_presence() - synthesize event if presence has changed
157 * @ctrl: controller to check
158 *
159 * On probe and resume, an explicit presence check is necessary to bring up an
160 * occupied slot or bring down an unoccupied slot. This can't be triggered by
161 * events in the Slot Status register, they may be stale and are therefore
162 * cleared. Secondly, sending an interrupt for "events that occur while
163 * interrupt generation is disabled [when] interrupt generation is subsequently
164 * enabled" is optional per PCIe r4.0, sec 6.7.3.4.
165 */
166static void pciehp_check_presence(struct controller *ctrl)
167{
168 int occupied;
169
170 down_read_nested(sem: &ctrl->reset_lock, subclass: ctrl->depth);
171 mutex_lock(&ctrl->state_lock);
172
173 occupied = pciehp_card_present_or_link_active(ctrl);
174 if ((occupied > 0 && (ctrl->state == OFF_STATE ||
175 ctrl->state == BLINKINGON_STATE)) ||
176 (!occupied && (ctrl->state == ON_STATE ||
177 ctrl->state == BLINKINGOFF_STATE)))
178 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
179
180 mutex_unlock(lock: &ctrl->state_lock);
181 up_read(sem: &ctrl->reset_lock);
182}
183
184static int pciehp_probe(struct pcie_device *dev)
185{
186 int rc;
187 struct controller *ctrl;
188
189 /* If this is not a "hotplug" service, we have no business here. */
190 if (dev->service != PCIE_PORT_SERVICE_HP)
191 return -ENODEV;
192
193 if (!dev->port->subordinate) {
194 /* Can happen if we run out of bus numbers during probe */
195 pci_err(dev->port,
196 "Hotplug bridge without secondary bus, ignoring\n");
197 return -ENODEV;
198 }
199
200 ctrl = pcie_init(dev);
201 if (!ctrl) {
202 pci_err(dev->port, "Controller initialization failed\n");
203 return -ENODEV;
204 }
205 set_service_data(dev, data: ctrl);
206
207 /* Setup the slot information structures */
208 rc = init_slot(ctrl);
209 if (rc) {
210 if (rc == -EBUSY)
211 ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n");
212 else
213 ctrl_err(ctrl, "Slot initialization failed (%d)\n", rc);
214 goto err_out_release_ctlr;
215 }
216
217 /* Enable events after we have setup the data structures */
218 rc = pcie_init_notification(ctrl);
219 if (rc) {
220 ctrl_err(ctrl, "Notification initialization failed (%d)\n", rc);
221 goto err_out_free_ctrl_slot;
222 }
223
224 /* Publish to user space */
225 rc = pci_hp_add(slot: &ctrl->hotplug_slot);
226 if (rc) {
227 ctrl_err(ctrl, "Publication to user space failed (%d)\n", rc);
228 goto err_out_shutdown_notification;
229 }
230
231 pciehp_check_presence(ctrl);
232
233 return 0;
234
235err_out_shutdown_notification:
236 pcie_shutdown_notification(ctrl);
237err_out_free_ctrl_slot:
238 cleanup_slot(ctrl);
239err_out_release_ctlr:
240 pciehp_release_ctrl(ctrl);
241 return -ENODEV;
242}
243
244static void pciehp_remove(struct pcie_device *dev)
245{
246 struct controller *ctrl = get_service_data(dev);
247
248 pci_hp_del(slot: &ctrl->hotplug_slot);
249 pcie_shutdown_notification(ctrl);
250 cleanup_slot(ctrl);
251 pciehp_release_ctrl(ctrl);
252}
253
254#ifdef CONFIG_PM
255static bool pme_is_native(struct pcie_device *dev)
256{
257 const struct pci_host_bridge *host;
258
259 host = pci_find_host_bridge(bus: dev->port->bus);
260 return pcie_ports_native || host->native_pme;
261}
262
263static void pciehp_disable_interrupt(struct pcie_device *dev)
264{
265 /*
266 * Disable hotplug interrupt so that it does not trigger
267 * immediately when the downstream link goes down.
268 */
269 if (pme_is_native(dev))
270 pcie_disable_interrupt(ctrl: get_service_data(dev));
271}
272
273#ifdef CONFIG_PM_SLEEP
274static int pciehp_suspend(struct pcie_device *dev)
275{
276 /*
277 * If the port is already runtime suspended we can keep it that
278 * way.
279 */
280 if (dev_pm_skip_suspend(dev: &dev->port->dev))
281 return 0;
282
283 pciehp_disable_interrupt(dev);
284 return 0;
285}
286
287static int pciehp_resume_noirq(struct pcie_device *dev)
288{
289 struct controller *ctrl = get_service_data(dev);
290
291 /* pci_restore_state() just wrote to the Slot Control register */
292 ctrl->cmd_started = jiffies;
293 ctrl->cmd_busy = true;
294
295 /* clear spurious events from rediscovery of inserted card */
296 if (ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) {
297 pcie_clear_hotplug_events(ctrl);
298
299 /*
300 * If hotplugged device was replaced with a different one
301 * during system sleep, mark the old device disconnected
302 * (to prevent its driver from accessing the new device)
303 * and synthesize a Presence Detect Changed event.
304 */
305 if (pciehp_device_replaced(ctrl)) {
306 ctrl_dbg(ctrl, "device replaced during system sleep\n");
307 pci_walk_bus(top: ctrl->pcie->port->subordinate,
308 cb: pci_dev_set_disconnected, NULL);
309 pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
310 }
311 }
312
313 return 0;
314}
315#endif
316
317static int pciehp_resume(struct pcie_device *dev)
318{
319 struct controller *ctrl = get_service_data(dev);
320
321 if (pme_is_native(dev))
322 pcie_enable_interrupt(ctrl);
323
324 pciehp_check_presence(ctrl);
325
326 return 0;
327}
328
329static int pciehp_runtime_suspend(struct pcie_device *dev)
330{
331 pciehp_disable_interrupt(dev);
332 return 0;
333}
334
335static int pciehp_runtime_resume(struct pcie_device *dev)
336{
337 struct controller *ctrl = get_service_data(dev);
338
339 /* pci_restore_state() just wrote to the Slot Control register */
340 ctrl->cmd_started = jiffies;
341 ctrl->cmd_busy = true;
342
343 /* clear spurious events from rediscovery of inserted card */
344 if ((ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) &&
345 pme_is_native(dev))
346 pcie_clear_hotplug_events(ctrl);
347
348 return pciehp_resume(dev);
349}
350#endif /* PM */
351
352static struct pcie_port_service_driver hpdriver_portdrv = {
353 .name = "pciehp",
354 .port_type = PCIE_ANY_PORT,
355 .service = PCIE_PORT_SERVICE_HP,
356
357 .probe = pciehp_probe,
358 .remove = pciehp_remove,
359
360#ifdef CONFIG_PM
361#ifdef CONFIG_PM_SLEEP
362 .suspend = pciehp_suspend,
363 .resume_noirq = pciehp_resume_noirq,
364 .resume = pciehp_resume,
365#endif
366 .runtime_suspend = pciehp_runtime_suspend,
367 .runtime_resume = pciehp_runtime_resume,
368#endif /* PM */
369
370 .slot_reset = pciehp_slot_reset,
371};
372
373int __init pcie_hp_init(void)
374{
375 int retval = 0;
376
377 retval = pcie_port_service_register(new: &hpdriver_portdrv);
378 pr_debug("pcie_port_service_register = %d\n", retval);
379 if (retval)
380 pr_debug("Failure to register service\n");
381
382 return retval;
383}
384

source code of linux/drivers/pci/hotplug/pciehp_core.c