xref: /linux/drivers/pci/hotplug/shpchp_core.c (revision 69050f8d6d075dc01af7a5f2f550a8067510366f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Standard 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  */
15 
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/kernel.h>
19 #include <linux/types.h>
20 #include <linux/slab.h>
21 #include <linux/pci.h>
22 #include "shpchp.h"
23 
24 /* Global variables */
25 bool shpchp_poll_mode;
26 int shpchp_poll_time;
27 
28 #define DRIVER_VERSION	"0.4"
29 #define DRIVER_AUTHOR	"Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
30 #define DRIVER_DESC	"Standard Hot Plug PCI Controller Driver"
31 
32 MODULE_AUTHOR(DRIVER_AUTHOR);
33 MODULE_DESCRIPTION(DRIVER_DESC);
34 
35 module_param(shpchp_poll_mode, bool, 0644);
36 module_param(shpchp_poll_time, int, 0644);
37 MODULE_PARM_DESC(shpchp_poll_mode, "Using polling mechanism for hot-plug events or not");
38 MODULE_PARM_DESC(shpchp_poll_time, "Polling mechanism frequency, in seconds");
39 
40 #define SHPC_MODULE_NAME "shpchp"
41 
42 static int set_attention_status(struct hotplug_slot *slot, u8 value);
43 static int enable_slot(struct hotplug_slot *slot);
44 static int disable_slot(struct hotplug_slot *slot);
45 static int get_power_status(struct hotplug_slot *slot, u8 *value);
46 static int get_attention_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 
50 static const struct hotplug_slot_ops shpchp_hotplug_slot_ops = {
51 	.set_attention_status =	set_attention_status,
52 	.enable_slot =		enable_slot,
53 	.disable_slot =		disable_slot,
54 	.get_power_status =	get_power_status,
55 	.get_attention_status =	get_attention_status,
56 	.get_latch_status =	get_latch_status,
57 	.get_adapter_status =	get_adapter_status,
58 };
59 
60 static int init_slots(struct controller *ctrl)
61 {
62 	struct slot *slot;
63 	struct hotplug_slot *hotplug_slot;
64 	char name[SLOT_NAME_SIZE];
65 	int retval;
66 	int i;
67 
68 	for (i = 0; i < ctrl->num_slots; i++) {
69 		slot = kzalloc_obj(*slot, GFP_KERNEL);
70 		if (!slot) {
71 			retval = -ENOMEM;
72 			goto error;
73 		}
74 
75 		hotplug_slot = &slot->hotplug_slot;
76 
77 		slot->hp_slot = i;
78 		slot->ctrl = ctrl;
79 		slot->bus = ctrl->pci_dev->subordinate->number;
80 		slot->device = ctrl->slot_device_offset + i;
81 		slot->number = ctrl->first_slot + (ctrl->slot_num_inc * i);
82 
83 		slot->wq = alloc_workqueue("shpchp-%d", WQ_PERCPU, 0,
84 					   slot->number);
85 		if (!slot->wq) {
86 			retval = -ENOMEM;
87 			goto error_slot;
88 		}
89 
90 		mutex_init(&slot->lock);
91 		INIT_DELAYED_WORK(&slot->work, shpchp_queue_pushbutton_work);
92 
93 		/* register this slot with the hotplug pci core */
94 		snprintf(name, SLOT_NAME_SIZE, "%d", slot->number);
95 		hotplug_slot->ops = &shpchp_hotplug_slot_ops;
96 
97 		ctrl_dbg(ctrl, "Registering domain:bus:dev=%04x:%02x:%02x hp_slot=%x sun=%x slot_device_offset=%x\n",
98 			 pci_domain_nr(ctrl->pci_dev->subordinate),
99 			 slot->bus, slot->device, slot->hp_slot, slot->number,
100 			 ctrl->slot_device_offset);
101 		retval = pci_hp_register(hotplug_slot,
102 				ctrl->pci_dev->subordinate, slot->device, name);
103 		if (retval) {
104 			ctrl_err(ctrl, "pci_hp_register failed with error %d\n",
105 				 retval);
106 			goto error_slotwq;
107 		}
108 
109 		get_power_status(hotplug_slot, &slot->pwr_save);
110 		get_attention_status(hotplug_slot, &slot->attention_save);
111 		get_latch_status(hotplug_slot, &slot->latch_save);
112 		get_adapter_status(hotplug_slot, &slot->presence_save);
113 
114 		list_add(&slot->slot_list, &ctrl->slot_list);
115 	}
116 
117 	return 0;
118 error_slotwq:
119 	destroy_workqueue(slot->wq);
120 error_slot:
121 	kfree(slot);
122 error:
123 	return retval;
124 }
125 
126 void cleanup_slots(struct controller *ctrl)
127 {
128 	struct slot *slot, *next;
129 
130 	list_for_each_entry_safe(slot, next, &ctrl->slot_list, slot_list) {
131 		list_del(&slot->slot_list);
132 		cancel_delayed_work(&slot->work);
133 		destroy_workqueue(slot->wq);
134 		pci_hp_deregister(&slot->hotplug_slot);
135 		kfree(slot);
136 	}
137 }
138 
139 /*
140  * set_attention_status - Turns the Amber LED for a slot on, off or blink
141  */
142 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
143 {
144 	struct slot *slot = get_slot(hotplug_slot);
145 
146 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
147 		 __func__, slot_name(slot));
148 
149 	slot->attention_save = status;
150 	shpchp_set_attention_status(slot, status);
151 
152 	return 0;
153 }
154 
155 static int enable_slot(struct hotplug_slot *hotplug_slot)
156 {
157 	struct slot *slot = get_slot(hotplug_slot);
158 
159 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
160 		 __func__, slot_name(slot));
161 
162 	return shpchp_sysfs_enable_slot(slot);
163 }
164 
165 static int disable_slot(struct hotplug_slot *hotplug_slot)
166 {
167 	struct slot *slot = get_slot(hotplug_slot);
168 
169 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
170 		 __func__, slot_name(slot));
171 
172 	return shpchp_sysfs_disable_slot(slot);
173 }
174 
175 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
176 {
177 	struct slot *slot = get_slot(hotplug_slot);
178 	int retval;
179 
180 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
181 		 __func__, slot_name(slot));
182 
183 	retval = shpchp_get_power_status(slot, value);
184 	if (retval < 0)
185 		*value = slot->pwr_save;
186 
187 	return 0;
188 }
189 
190 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
191 {
192 	struct slot *slot = get_slot(hotplug_slot);
193 	int retval;
194 
195 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
196 		 __func__, slot_name(slot));
197 
198 	retval = shpchp_get_attention_status(slot, value);
199 	if (retval < 0)
200 		*value = slot->attention_save;
201 
202 	return 0;
203 }
204 
205 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
206 {
207 	struct slot *slot = get_slot(hotplug_slot);
208 	int retval;
209 
210 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
211 		 __func__, slot_name(slot));
212 
213 	retval = shpchp_get_latch_status(slot, value);
214 	if (retval < 0)
215 		*value = slot->latch_save;
216 
217 	return 0;
218 }
219 
220 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
221 {
222 	struct slot *slot = get_slot(hotplug_slot);
223 	int retval;
224 
225 	ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
226 		 __func__, slot_name(slot));
227 
228 	retval = shpchp_get_adapter_status(slot, value);
229 	if (retval < 0)
230 		*value = slot->presence_save;
231 
232 	return 0;
233 }
234 
235 static bool shpc_capable(struct pci_dev *bridge)
236 {
237 	/*
238 	 * It is assumed that AMD GOLAM chips support SHPC but they do not
239 	 * have SHPC capability.
240 	 */
241 	if (bridge->vendor == PCI_VENDOR_ID_AMD &&
242 	    bridge->device == PCI_DEVICE_ID_AMD_GOLAM_7450)
243 		return true;
244 
245 	if (pci_find_capability(bridge, PCI_CAP_ID_SHPC))
246 		return true;
247 
248 	return false;
249 }
250 
251 static int shpc_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
252 {
253 	int rc;
254 	struct controller *ctrl;
255 
256 	if (!shpc_capable(pdev))
257 		return -ENODEV;
258 
259 	if (acpi_get_hp_hw_control_from_firmware(pdev))
260 		return -ENODEV;
261 
262 	ctrl = kzalloc_obj(*ctrl, GFP_KERNEL);
263 	if (!ctrl)
264 		goto err_out_none;
265 
266 	INIT_LIST_HEAD(&ctrl->slot_list);
267 
268 	rc = shpc_init(ctrl, pdev);
269 	if (rc) {
270 		ctrl_dbg(ctrl, "Controller initialization failed\n");
271 		goto err_out_free_ctrl;
272 	}
273 
274 	pci_set_drvdata(pdev, ctrl);
275 
276 	/* Setup the slot information structures */
277 	rc = init_slots(ctrl);
278 	if (rc) {
279 		ctrl_err(ctrl, "Slot initialization failed\n");
280 		goto err_out_release_ctlr;
281 	}
282 
283 	rc = shpchp_create_ctrl_files(ctrl);
284 	if (rc)
285 		goto err_cleanup_slots;
286 
287 	pdev->shpc_managed = 1;
288 	return 0;
289 
290 err_cleanup_slots:
291 	cleanup_slots(ctrl);
292 err_out_release_ctlr:
293 	shpchp_release_ctlr(ctrl);
294 err_out_free_ctrl:
295 	kfree(ctrl);
296 err_out_none:
297 	return -ENODEV;
298 }
299 
300 static void shpc_remove(struct pci_dev *dev)
301 {
302 	struct controller *ctrl = pci_get_drvdata(dev);
303 
304 	dev->shpc_managed = 0;
305 	shpchp_remove_ctrl_files(ctrl);
306 	shpchp_release_ctlr(ctrl);
307 	kfree(ctrl);
308 }
309 
310 static const struct pci_device_id shpcd_pci_tbl[] = {
311 	{PCI_DEVICE_CLASS(PCI_CLASS_BRIDGE_PCI_NORMAL, ~0)},
312 	{ /* end: all zeroes */ }
313 };
314 MODULE_DEVICE_TABLE(pci, shpcd_pci_tbl);
315 
316 static struct pci_driver shpc_driver = {
317 	.name =		SHPC_MODULE_NAME,
318 	.id_table =	shpcd_pci_tbl,
319 	.probe =	shpc_probe,
320 	.remove =	shpc_remove,
321 };
322 
323 static int __init shpcd_init(void)
324 {
325 	return pci_register_driver(&shpc_driver);
326 }
327 
328 static void __exit shpcd_cleanup(void)
329 {
330 	pci_unregister_driver(&shpc_driver);
331 }
332 
333 module_init(shpcd_init);
334 module_exit(shpcd_cleanup);
335