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