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 */ |
34 | bool pciehp_poll_mode; |
35 | int 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 | */ |
41 | module_param(pciehp_poll_mode, bool, 0644); |
42 | module_param(pciehp_poll_time, int, 0644); |
43 | MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not" ); |
44 | MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds" ); |
45 | |
46 | static int set_attention_status(struct hotplug_slot *slot, u8 value); |
47 | static int get_power_status(struct hotplug_slot *slot, u8 *value); |
48 | static int get_latch_status(struct hotplug_slot *slot, u8 *value); |
49 | static int get_adapter_status(struct hotplug_slot *slot, u8 *value); |
50 | |
51 | static 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(size: 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 | |
90 | static 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 | */ |
101 | static 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 | |
117 | static 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 | |
128 | static 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 | |
139 | static 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 | */ |
166 | static 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 | |
184 | static 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 | |
235 | err_out_shutdown_notification: |
236 | pcie_shutdown_notification(ctrl); |
237 | err_out_free_ctrl_slot: |
238 | cleanup_slot(ctrl); |
239 | err_out_release_ctlr: |
240 | pciehp_release_ctrl(ctrl); |
241 | return -ENODEV; |
242 | } |
243 | |
244 | static 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 |
255 | static 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 | |
263 | static 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 |
274 | static 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 | |
287 | static 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 | return 0; |
300 | } |
301 | #endif |
302 | |
303 | static int pciehp_resume(struct pcie_device *dev) |
304 | { |
305 | struct controller *ctrl = get_service_data(dev); |
306 | |
307 | if (pme_is_native(dev)) |
308 | pcie_enable_interrupt(ctrl); |
309 | |
310 | pciehp_check_presence(ctrl); |
311 | |
312 | return 0; |
313 | } |
314 | |
315 | static int pciehp_runtime_suspend(struct pcie_device *dev) |
316 | { |
317 | pciehp_disable_interrupt(dev); |
318 | return 0; |
319 | } |
320 | |
321 | static int pciehp_runtime_resume(struct pcie_device *dev) |
322 | { |
323 | struct controller *ctrl = get_service_data(dev); |
324 | |
325 | /* pci_restore_state() just wrote to the Slot Control register */ |
326 | ctrl->cmd_started = jiffies; |
327 | ctrl->cmd_busy = true; |
328 | |
329 | /* clear spurious events from rediscovery of inserted card */ |
330 | if ((ctrl->state == ON_STATE || ctrl->state == BLINKINGOFF_STATE) && |
331 | pme_is_native(dev)) |
332 | pcie_clear_hotplug_events(ctrl); |
333 | |
334 | return pciehp_resume(dev); |
335 | } |
336 | #endif /* PM */ |
337 | |
338 | static struct pcie_port_service_driver hpdriver_portdrv = { |
339 | .name = "pciehp" , |
340 | .port_type = PCIE_ANY_PORT, |
341 | .service = PCIE_PORT_SERVICE_HP, |
342 | |
343 | .probe = pciehp_probe, |
344 | .remove = pciehp_remove, |
345 | |
346 | #ifdef CONFIG_PM |
347 | #ifdef CONFIG_PM_SLEEP |
348 | .suspend = pciehp_suspend, |
349 | .resume_noirq = pciehp_resume_noirq, |
350 | .resume = pciehp_resume, |
351 | #endif |
352 | .runtime_suspend = pciehp_runtime_suspend, |
353 | .runtime_resume = pciehp_runtime_resume, |
354 | #endif /* PM */ |
355 | |
356 | .slot_reset = pciehp_slot_reset, |
357 | }; |
358 | |
359 | int __init pcie_hp_init(void) |
360 | { |
361 | int retval = 0; |
362 | |
363 | retval = pcie_port_service_register(new: &hpdriver_portdrv); |
364 | pr_debug("pcie_port_service_register = %d\n" , retval); |
365 | if (retval) |
366 | pr_debug("Failure to register service\n" ); |
367 | |
368 | return retval; |
369 | } |
370 | |