xref: /linux/drivers/pci/hotplug/acpiphp_core.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ACPI PCI 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) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
9  * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
10  * Copyright (C) 2002,2003 NEC Corporation
11  * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org)
12  * Copyright (C) 2003-2005 Hewlett Packard
13  *
14  * All rights reserved.
15  *
16  * Send feedback to <kristen.c.accardi@intel.com>
17  *
18  */
19 
20 #define pr_fmt(fmt) "acpiphp: " fmt
21 
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 
26 #include <linux/kernel.h>
27 #include <linux/pci.h>
28 #include <linux/pci-acpi.h>
29 #include <linux/pci_hotplug.h>
30 #include <linux/slab.h>
31 #include <linux/smp.h>
32 #include "acpiphp.h"
33 
34 /* name size which is used for entries in pcihpfs */
35 #define SLOT_NAME_SIZE  21              /* {_SUN} */
36 
37 bool acpiphp_disabled;
38 
39 /* local variables */
40 static struct acpiphp_attention_info *attention_info;
41 
42 #define DRIVER_VERSION	"0.5"
43 #define DRIVER_AUTHOR	"Greg Kroah-Hartman <gregkh@us.ibm.com>, Takayoshi Kochi <t-kochi@bq.jp.nec.com>, Matthew Wilcox <willy@infradead.org>"
44 #define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver"
45 
46 MODULE_AUTHOR(DRIVER_AUTHOR);
47 MODULE_DESCRIPTION(DRIVER_DESC);
48 MODULE_PARM_DESC(disable, "disable acpiphp driver");
49 module_param_named(disable, acpiphp_disabled, bool, 0444);
50 
51 static int enable_slot(struct hotplug_slot *slot);
52 static int disable_slot(struct hotplug_slot *slot);
53 static int set_attention_status(struct hotplug_slot *slot, u8 value);
54 static int get_power_status(struct hotplug_slot *slot, u8 *value);
55 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
56 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
57 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
58 
59 static const struct hotplug_slot_ops acpi_hotplug_slot_ops = {
60 	.enable_slot		= enable_slot,
61 	.disable_slot		= disable_slot,
62 	.set_attention_status	= set_attention_status,
63 	.get_power_status	= get_power_status,
64 	.get_attention_status	= get_attention_status,
65 	.get_latch_status	= get_latch_status,
66 	.get_adapter_status	= get_adapter_status,
67 };
68 
69 /**
70  * acpiphp_register_attention - set attention LED callback
71  * @info: must be completely filled with LED callbacks
72  *
73  * Description: This is used to register a hardware specific ACPI
74  * driver that manipulates the attention LED.  All the fields in
75  * info must be set.
76  */
acpiphp_register_attention(struct acpiphp_attention_info * info)77 int acpiphp_register_attention(struct acpiphp_attention_info *info)
78 {
79 	int retval = -EINVAL;
80 
81 	if (info && info->set_attn && info->get_attn && !attention_info) {
82 		retval = 0;
83 		attention_info = info;
84 	}
85 	return retval;
86 }
87 EXPORT_SYMBOL_GPL(acpiphp_register_attention);
88 
89 
90 /**
91  * acpiphp_unregister_attention - unset attention LED callback
92  * @info: must match the pointer used to register
93  *
94  * Description: This is used to un-register a hardware specific acpi
95  * driver that manipulates the attention LED.  The pointer to the
96  * info struct must be the same as the one used to set it.
97  */
acpiphp_unregister_attention(struct acpiphp_attention_info * info)98 int acpiphp_unregister_attention(struct acpiphp_attention_info *info)
99 {
100 	int retval = -EINVAL;
101 
102 	if (info && attention_info == info) {
103 		attention_info = NULL;
104 		retval = 0;
105 	}
106 	return retval;
107 }
108 EXPORT_SYMBOL_GPL(acpiphp_unregister_attention);
109 
110 
111 /**
112  * enable_slot - power on and enable a slot
113  * @hotplug_slot: slot to enable
114  *
115  * Actual tasks are done in acpiphp_enable_slot()
116  */
enable_slot(struct hotplug_slot * hotplug_slot)117 static int enable_slot(struct hotplug_slot *hotplug_slot)
118 {
119 	struct slot *slot = to_slot(hotplug_slot);
120 
121 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
122 
123 	/* enable the specified slot */
124 	return acpiphp_enable_slot(slot->acpi_slot);
125 }
126 
127 
128 /**
129  * disable_slot - disable and power off a slot
130  * @hotplug_slot: slot to disable
131  *
132  * Actual tasks are done in acpiphp_disable_slot()
133  */
disable_slot(struct hotplug_slot * hotplug_slot)134 static int disable_slot(struct hotplug_slot *hotplug_slot)
135 {
136 	struct slot *slot = to_slot(hotplug_slot);
137 
138 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
139 
140 	/* disable the specified slot */
141 	return acpiphp_disable_slot(slot->acpi_slot);
142 }
143 
144 
145 /**
146  * set_attention_status - set attention LED
147  * @hotplug_slot: slot to set attention LED on
148  * @status: value to set attention LED to (0 or 1)
149  *
150  * attention status LED, so we use a callback that
151  * was registered with us.  This allows hardware specific
152  * ACPI implementations to blink the light for us.
153  */
set_attention_status(struct hotplug_slot * hotplug_slot,u8 status)154 static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
155 {
156 	int retval = -ENODEV;
157 
158 	pr_debug("%s - physical_slot = %s\n", __func__,
159 		hotplug_slot_name(hotplug_slot));
160 
161 	if (attention_info && try_module_get(attention_info->owner)) {
162 		retval = attention_info->set_attn(hotplug_slot, status);
163 		module_put(attention_info->owner);
164 	} else
165 		attention_info = NULL;
166 	return retval;
167 }
168 
169 
170 /**
171  * get_power_status - get power status of a slot
172  * @hotplug_slot: slot to get status
173  * @value: pointer to store status
174  *
175  * Some platforms may not implement _STA method properly.
176  * In that case, the value returned may not be reliable.
177  */
get_power_status(struct hotplug_slot * hotplug_slot,u8 * value)178 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
179 {
180 	struct slot *slot = to_slot(hotplug_slot);
181 
182 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
183 
184 	*value = acpiphp_get_power_status(slot->acpi_slot);
185 
186 	return 0;
187 }
188 
189 
190 /**
191  * get_attention_status - get attention LED status
192  * @hotplug_slot: slot to get status from
193  * @value: returns with value of attention LED
194  *
195  * ACPI doesn't have known method to determine the state
196  * of the attention status LED, so we use a callback that
197  * was registered with us.  This allows hardware specific
198  * ACPI implementations to determine its state.
199  */
get_attention_status(struct hotplug_slot * hotplug_slot,u8 * value)200 static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
201 {
202 	int retval = -EINVAL;
203 
204 	pr_debug("%s - physical_slot = %s\n", __func__,
205 		hotplug_slot_name(hotplug_slot));
206 
207 	if (attention_info && try_module_get(attention_info->owner)) {
208 		retval = attention_info->get_attn(hotplug_slot, value);
209 		module_put(attention_info->owner);
210 	} else
211 		attention_info = NULL;
212 	return retval;
213 }
214 
215 
216 /**
217  * get_latch_status - get latch status of a slot
218  * @hotplug_slot: slot to get status
219  * @value: pointer to store status
220  *
221  * ACPI doesn't provide any formal means to access latch status.
222  * Instead, we fake latch status from _STA.
223  */
get_latch_status(struct hotplug_slot * hotplug_slot,u8 * value)224 static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
225 {
226 	struct slot *slot = to_slot(hotplug_slot);
227 
228 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
229 
230 	*value = acpiphp_get_latch_status(slot->acpi_slot);
231 
232 	return 0;
233 }
234 
235 
236 /**
237  * get_adapter_status - get adapter status of a slot
238  * @hotplug_slot: slot to get status
239  * @value: pointer to store status
240  *
241  * ACPI doesn't provide any formal means to access adapter status.
242  * Instead, we fake adapter status from _STA.
243  */
get_adapter_status(struct hotplug_slot * hotplug_slot,u8 * value)244 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
245 {
246 	struct slot *slot = to_slot(hotplug_slot);
247 
248 	pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
249 
250 	*value = acpiphp_get_adapter_status(slot->acpi_slot);
251 
252 	return 0;
253 }
254 
255 /* callback routine to initialize 'struct slot' for each slot */
acpiphp_register_hotplug_slot(struct acpiphp_slot * acpiphp_slot,unsigned int sun)256 int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot,
257 				  unsigned int sun)
258 {
259 	struct slot *slot;
260 	int retval = -ENOMEM;
261 	char name[SLOT_NAME_SIZE];
262 
263 	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
264 	if (!slot)
265 		goto error;
266 
267 	slot->hotplug_slot.ops = &acpi_hotplug_slot_ops;
268 
269 	slot->acpi_slot = acpiphp_slot;
270 
271 	acpiphp_slot->slot = slot;
272 	slot->sun = sun;
273 	snprintf(name, SLOT_NAME_SIZE, "%u", sun);
274 
275 	retval = pci_hp_register(&slot->hotplug_slot, acpiphp_slot->bus,
276 				 acpiphp_slot->device, name);
277 	if (retval == -EBUSY)
278 		goto error_slot;
279 	if (retval) {
280 		pr_err("pci_hp_register failed with error %d\n", retval);
281 		goto error_slot;
282 	}
283 
284 	pr_info("Slot [%s] registered\n", slot_name(slot));
285 
286 	return 0;
287 error_slot:
288 	kfree(slot);
289 error:
290 	return retval;
291 }
292 
293 
acpiphp_unregister_hotplug_slot(struct acpiphp_slot * acpiphp_slot)294 void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
295 {
296 	struct slot *slot = acpiphp_slot->slot;
297 
298 	pr_info("Slot [%s] unregistered\n", slot_name(slot));
299 
300 	pci_hp_deregister(&slot->hotplug_slot);
301 	kfree(slot);
302 }
303 
304 
acpiphp_init(void)305 void __init acpiphp_init(void)
306 {
307 	pr_info(DRIVER_DESC " version: " DRIVER_VERSION "%s\n",
308 		acpiphp_disabled ? ", disabled by user; please report a bug"
309 				 : "");
310 }
311