1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * EDAC PCI component
4 *
5 * Author: Dave Jiang <djiang@mvista.com>
6 *
7 * 2007 (c) MontaVista Software, Inc.
8 */
9#include <asm/page.h>
10#include <linux/uaccess.h>
11#include <linux/ctype.h>
12#include <linux/highmem.h>
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/smp.h>
17#include <linux/spinlock.h>
18#include <linux/sysctl.h>
19#include <linux/timer.h>
20
21#include "edac_pci.h"
22#include "edac_module.h"
23
24static DEFINE_MUTEX(edac_pci_ctls_mutex);
25static LIST_HEAD(edac_pci_list);
26static atomic_t pci_indexes = ATOMIC_INIT(0);
27
28struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
29						  const char *edac_pci_name)
30{
31	struct edac_pci_ctl_info *pci;
32
33	edac_dbg(1, "\n");
34
35	pci = kzalloc(sizeof(struct edac_pci_ctl_info), GFP_KERNEL);
36	if (!pci)
37		return NULL;
38
39	if (sz_pvt) {
40		pci->pvt_info = kzalloc(sz_pvt, GFP_KERNEL);
41		if (!pci->pvt_info)
42			goto free;
43	}
44
45	pci->op_state = OP_ALLOC;
46
47	snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);
48
49	return pci;
50
51free:
52	kfree(pci);
53	return NULL;
54}
55EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);
56
57void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
58{
59	edac_dbg(1, "\n");
60
61	edac_pci_remove_sysfs(pci);
62}
63EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);
64
65/*
66 * find_edac_pci_by_dev()
67 * 	scans the edac_pci list for a specific 'struct device *'
68 *
69 *	return NULL if not found, or return control struct pointer
70 */
71static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
72{
73	struct edac_pci_ctl_info *pci;
74	struct list_head *item;
75
76	edac_dbg(1, "\n");
77
78	list_for_each(item, &edac_pci_list) {
79		pci = list_entry(item, struct edac_pci_ctl_info, link);
80
81		if (pci->dev == dev)
82			return pci;
83	}
84
85	return NULL;
86}
87
88/*
89 * add_edac_pci_to_global_list
90 * 	Before calling this function, caller must assign a unique value to
91 * 	edac_dev->pci_idx.
92 * 	Return:
93 * 		0 on success
94 * 		1 on failure
95 */
96static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
97{
98	struct list_head *item, *insert_before;
99	struct edac_pci_ctl_info *rover;
100
101	edac_dbg(1, "\n");
102
103	insert_before = &edac_pci_list;
104
105	/* Determine if already on the list */
106	rover = find_edac_pci_by_dev(pci->dev);
107	if (unlikely(rover != NULL))
108		goto fail0;
109
110	/* Insert in ascending order by 'pci_idx', so find position */
111	list_for_each(item, &edac_pci_list) {
112		rover = list_entry(item, struct edac_pci_ctl_info, link);
113
114		if (rover->pci_idx >= pci->pci_idx) {
115			if (unlikely(rover->pci_idx == pci->pci_idx))
116				goto fail1;
117
118			insert_before = item;
119			break;
120		}
121	}
122
123	list_add_tail_rcu(&pci->link, insert_before);
124	return 0;
125
126fail0:
127	edac_printk(KERN_WARNING, EDAC_PCI,
128		"%s (%s) %s %s already assigned %d\n",
129		dev_name(rover->dev), edac_dev_name(rover),
130		rover->mod_name, rover->ctl_name, rover->pci_idx);
131	return 1;
132
133fail1:
134	edac_printk(KERN_WARNING, EDAC_PCI,
135		"but in low-level driver: attempt to assign\n"
136		"\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
137		__func__);
138	return 1;
139}
140
141/*
142 * del_edac_pci_from_global_list
143 *
144 *	remove the PCI control struct from the global list
145 */
146static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
147{
148	list_del_rcu(&pci->link);
149
150	/* these are for safe removal of devices from global list while
151	 * NMI handlers may be traversing list
152	 */
153	synchronize_rcu();
154	INIT_LIST_HEAD(&pci->link);
155}
156
157/*
158 * edac_pci_workq_function()
159 *
160 * 	periodic function that performs the operation
161 *	scheduled by a workq request, for a given PCI control struct
162 */
163static void edac_pci_workq_function(struct work_struct *work_req)
164{
165	struct delayed_work *d_work = to_delayed_work(work_req);
166	struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
167	int msec;
168	unsigned long delay;
169
170	edac_dbg(3, "checking\n");
171
172	mutex_lock(&edac_pci_ctls_mutex);
173
174	if (pci->op_state != OP_RUNNING_POLL) {
175		mutex_unlock(&edac_pci_ctls_mutex);
176		return;
177	}
178
179	if (edac_pci_get_check_errors())
180		pci->edac_check(pci);
181
182	/* if we are on a one second period, then use round */
183	msec = edac_pci_get_poll_msec();
184	if (msec == 1000)
185		delay = round_jiffies_relative(msecs_to_jiffies(msec));
186	else
187		delay = msecs_to_jiffies(msec);
188
189	edac_queue_work(&pci->work, delay);
190
191	mutex_unlock(&edac_pci_ctls_mutex);
192}
193
194int edac_pci_alloc_index(void)
195{
196	return atomic_inc_return(&pci_indexes) - 1;
197}
198EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
199
200int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
201{
202	edac_dbg(0, "\n");
203
204	pci->pci_idx = edac_idx;
205	pci->start_time = jiffies;
206
207	mutex_lock(&edac_pci_ctls_mutex);
208
209	if (add_edac_pci_to_global_list(pci))
210		goto fail0;
211
212	if (edac_pci_create_sysfs(pci)) {
213		edac_pci_printk(pci, KERN_WARNING,
214				"failed to create sysfs pci\n");
215		goto fail1;
216	}
217
218	if (pci->edac_check) {
219		pci->op_state = OP_RUNNING_POLL;
220
221		INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
222		edac_queue_work(&pci->work, msecs_to_jiffies(edac_pci_get_poll_msec()));
223
224	} else {
225		pci->op_state = OP_RUNNING_INTERRUPT;
226	}
227
228	edac_pci_printk(pci, KERN_INFO,
229		"Giving out device to module %s controller %s: DEV %s (%s)\n",
230		pci->mod_name, pci->ctl_name, pci->dev_name,
231		edac_op_state_to_string(pci->op_state));
232
233	mutex_unlock(&edac_pci_ctls_mutex);
234	return 0;
235
236	/* error unwind stack */
237fail1:
238	del_edac_pci_from_global_list(pci);
239fail0:
240	mutex_unlock(&edac_pci_ctls_mutex);
241	return 1;
242}
243EXPORT_SYMBOL_GPL(edac_pci_add_device);
244
245struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
246{
247	struct edac_pci_ctl_info *pci;
248
249	edac_dbg(0, "\n");
250
251	mutex_lock(&edac_pci_ctls_mutex);
252
253	/* ensure the control struct is on the global list
254	 * if not, then leave
255	 */
256	pci = find_edac_pci_by_dev(dev);
257	if (pci  == NULL) {
258		mutex_unlock(&edac_pci_ctls_mutex);
259		return NULL;
260	}
261
262	pci->op_state = OP_OFFLINE;
263
264	del_edac_pci_from_global_list(pci);
265
266	mutex_unlock(&edac_pci_ctls_mutex);
267
268	if (pci->edac_check)
269		edac_stop_work(&pci->work);
270
271	edac_printk(KERN_INFO, EDAC_PCI,
272		"Removed device %d for %s %s: DEV %s\n",
273		pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
274
275	return pci;
276}
277EXPORT_SYMBOL_GPL(edac_pci_del_device);
278
279/*
280 * edac_pci_generic_check
281 *
282 *	a Generic parity check API
283 */
284static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
285{
286	edac_dbg(4, "\n");
287	edac_pci_do_parity_check();
288}
289
290/* free running instance index counter */
291static int edac_pci_idx;
292#define EDAC_PCI_GENCTL_NAME	"EDAC PCI controller"
293
294struct edac_pci_gen_data {
295	int edac_idx;
296};
297
298struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
299						const char *mod_name)
300{
301	struct edac_pci_ctl_info *pci;
302	struct edac_pci_gen_data *pdata;
303
304	pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
305	if (!pci)
306		return NULL;
307
308	pdata = pci->pvt_info;
309	pci->dev = dev;
310	dev_set_drvdata(pci->dev, pci);
311	pci->dev_name = pci_name(to_pci_dev(dev));
312
313	pci->mod_name = mod_name;
314	pci->ctl_name = EDAC_PCI_GENCTL_NAME;
315	if (edac_op_state == EDAC_OPSTATE_POLL)
316		pci->edac_check = edac_pci_generic_check;
317
318	pdata->edac_idx = edac_pci_idx++;
319
320	if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
321		edac_dbg(3, "failed edac_pci_add_device()\n");
322		edac_pci_free_ctl_info(pci);
323		return NULL;
324	}
325
326	return pci;
327}
328EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
329
330void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
331{
332	edac_dbg(0, "pci mod=%s\n", pci->mod_name);
333
334	edac_pci_del_device(pci->dev);
335	edac_pci_free_ctl_info(pci);
336}
337EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);
338