pciehp_core.c

  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(name, SLOT_NAME_SIZE, "%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(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(hotplug_slot);
 95	kfree(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(pdev);
112	pciehp_set_indicators(ctrl, INDICATOR_NOOP, status);
113	pci_config_pm_runtime_put(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(pdev);
123	pciehp_get_power_status(ctrl, value);
124	pci_config_pm_runtime_put(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(pdev);
134	pciehp_get_latch_status(ctrl, value);
135	pci_config_pm_runtime_put(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(pdev);
146	ret = pciehp_card_present_or_link_active(ctrl);
147	pci_config_pm_runtime_put(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(&ctrl->reset_lock, 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(&ctrl->state_lock);
181	up_read(&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, 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(&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(&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(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(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->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(ctrl->pcie->port->subordinate,
308				     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(&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}