1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright(c) 2017 Intel Corporation. All rights reserved.
4 */
5 #include <linux/libnvdimm.h>
6 #include <linux/badblocks.h>
7 #include <linux/export.h>
8 #include <linux/module.h>
9 #include <linux/blkdev.h>
10 #include <linux/device.h>
11 #include <linux/ctype.h>
12 #include <linux/ndctl.h>
13 #include <linux/mutex.h>
14 #include <linux/slab.h>
15 #include <linux/io.h>
16 #include "nd-core.h"
17 #include "nd.h"
18
badrange_init(struct badrange * badrange)19 void badrange_init(struct badrange *badrange)
20 {
21 INIT_LIST_HEAD(&badrange->list);
22 spin_lock_init(&badrange->lock);
23 }
24 EXPORT_SYMBOL_GPL(badrange_init);
25
append_badrange_entry(struct badrange * badrange,struct badrange_entry * bre,u64 addr,u64 length)26 static void append_badrange_entry(struct badrange *badrange,
27 struct badrange_entry *bre, u64 addr, u64 length)
28 {
29 lockdep_assert_held(&badrange->lock);
30 bre->start = addr;
31 bre->length = length;
32 list_add_tail(&bre->list, &badrange->list);
33 }
34
alloc_and_append_badrange_entry(struct badrange * badrange,u64 addr,u64 length,gfp_t flags)35 static int alloc_and_append_badrange_entry(struct badrange *badrange,
36 u64 addr, u64 length, gfp_t flags)
37 {
38 struct badrange_entry *bre;
39
40 bre = kzalloc(sizeof(*bre), flags);
41 if (!bre)
42 return -ENOMEM;
43
44 append_badrange_entry(badrange, bre, addr, length);
45 return 0;
46 }
47
add_badrange(struct badrange * badrange,u64 addr,u64 length)48 static int add_badrange(struct badrange *badrange, u64 addr, u64 length)
49 {
50 struct badrange_entry *bre, *bre_new;
51
52 spin_unlock(&badrange->lock);
53 bre_new = kzalloc(sizeof(*bre_new), GFP_KERNEL);
54 spin_lock(&badrange->lock);
55
56 if (list_empty(&badrange->list)) {
57 if (!bre_new)
58 return -ENOMEM;
59 append_badrange_entry(badrange, bre_new, addr, length);
60 return 0;
61 }
62
63 /*
64 * There is a chance this is a duplicate, check for those first.
65 * This will be the common case as ARS_STATUS returns all known
66 * errors in the SPA space, and we can't query it per region
67 */
68 list_for_each_entry(bre, &badrange->list, list)
69 if (bre->start == addr) {
70 /* If length has changed, update this list entry */
71 if (bre->length != length)
72 bre->length = length;
73 kfree(bre_new);
74 return 0;
75 }
76
77 /*
78 * If not a duplicate or a simple length update, add the entry as is,
79 * as any overlapping ranges will get resolved when the list is consumed
80 * and converted to badblocks
81 */
82 if (!bre_new)
83 return -ENOMEM;
84 append_badrange_entry(badrange, bre_new, addr, length);
85
86 return 0;
87 }
88
badrange_add(struct badrange * badrange,u64 addr,u64 length)89 int badrange_add(struct badrange *badrange, u64 addr, u64 length)
90 {
91 int rc;
92
93 spin_lock(&badrange->lock);
94 rc = add_badrange(badrange, addr, length);
95 spin_unlock(&badrange->lock);
96
97 return rc;
98 }
99 EXPORT_SYMBOL_GPL(badrange_add);
100
badrange_forget(struct badrange * badrange,phys_addr_t start,unsigned int len)101 void badrange_forget(struct badrange *badrange, phys_addr_t start,
102 unsigned int len)
103 {
104 struct list_head *badrange_list = &badrange->list;
105 u64 clr_end = start + len - 1;
106 struct badrange_entry *bre, *next;
107
108 spin_lock(&badrange->lock);
109
110 /*
111 * [start, clr_end] is the badrange interval being cleared.
112 * [bre->start, bre_end] is the badrange_list entry we're comparing
113 * the above interval against. The badrange list entry may need
114 * to be modified (update either start or length), deleted, or
115 * split into two based on the overlap characteristics
116 */
117
118 list_for_each_entry_safe(bre, next, badrange_list, list) {
119 u64 bre_end = bre->start + bre->length - 1;
120
121 /* Skip intervals with no intersection */
122 if (bre_end < start)
123 continue;
124 if (bre->start > clr_end)
125 continue;
126 /* Delete completely overlapped badrange entries */
127 if ((bre->start >= start) && (bre_end <= clr_end)) {
128 list_del(&bre->list);
129 kfree(bre);
130 continue;
131 }
132 /* Adjust start point of partially cleared entries */
133 if ((start <= bre->start) && (clr_end > bre->start)) {
134 bre->length -= clr_end - bre->start + 1;
135 bre->start = clr_end + 1;
136 continue;
137 }
138 /* Adjust bre->length for partial clearing at the tail end */
139 if ((bre->start < start) && (bre_end <= clr_end)) {
140 /* bre->start remains the same */
141 bre->length = start - bre->start;
142 continue;
143 }
144 /*
145 * If clearing in the middle of an entry, we split it into
146 * two by modifying the current entry to represent one half of
147 * the split, and adding a new entry for the second half.
148 */
149 if ((bre->start < start) && (bre_end > clr_end)) {
150 u64 new_start = clr_end + 1;
151 u64 new_len = bre_end - new_start + 1;
152
153 /* Add new entry covering the right half */
154 alloc_and_append_badrange_entry(badrange, new_start,
155 new_len, GFP_NOWAIT);
156 /* Adjust this entry to cover the left half */
157 bre->length = start - bre->start;
158 continue;
159 }
160 }
161 spin_unlock(&badrange->lock);
162 }
163 EXPORT_SYMBOL_GPL(badrange_forget);
164
set_badblock(struct badblocks * bb,sector_t s,int num)165 static void set_badblock(struct badblocks *bb, sector_t s, int num)
166 {
167 dev_dbg(bb->dev, "Found a bad range (0x%llx, 0x%llx)\n",
168 (u64) s * 512, (u64) num * 512);
169 /* this isn't an error as the hardware will still throw an exception */
170 if (badblocks_set(bb, s, num, 1))
171 dev_info_once(bb->dev, "%s: failed for sector %llx\n",
172 __func__, (u64) s);
173 }
174
175 /**
176 * __add_badblock_range() - Convert a physical address range to bad sectors
177 * @bb: badblocks instance to populate
178 * @ns_offset: namespace offset where the error range begins (in bytes)
179 * @len: number of bytes of badrange to be added
180 *
181 * This assumes that the range provided with (ns_offset, len) is within
182 * the bounds of physical addresses for this namespace, i.e. lies in the
183 * interval [ns_start, ns_start + ns_size)
184 */
__add_badblock_range(struct badblocks * bb,u64 ns_offset,u64 len)185 static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
186 {
187 const unsigned int sector_size = 512;
188 sector_t start_sector, end_sector;
189 u64 num_sectors;
190 u32 rem;
191
192 start_sector = div_u64(ns_offset, sector_size);
193 end_sector = div_u64_rem(ns_offset + len, sector_size, &rem);
194 if (rem)
195 end_sector++;
196 num_sectors = end_sector - start_sector;
197
198 if (unlikely(num_sectors > (u64)INT_MAX)) {
199 u64 remaining = num_sectors;
200 sector_t s = start_sector;
201
202 while (remaining) {
203 int done = min_t(u64, remaining, INT_MAX);
204
205 set_badblock(bb, s, done);
206 remaining -= done;
207 s += done;
208 }
209 } else
210 set_badblock(bb, start_sector, num_sectors);
211 }
212
badblocks_populate(struct badrange * badrange,struct badblocks * bb,const struct range * range)213 static void badblocks_populate(struct badrange *badrange,
214 struct badblocks *bb, const struct range *range)
215 {
216 struct badrange_entry *bre;
217
218 if (list_empty(&badrange->list))
219 return;
220
221 list_for_each_entry(bre, &badrange->list, list) {
222 u64 bre_end = bre->start + bre->length - 1;
223
224 /* Discard intervals with no intersection */
225 if (bre_end < range->start)
226 continue;
227 if (bre->start > range->end)
228 continue;
229 /* Deal with any overlap after start of the namespace */
230 if (bre->start >= range->start) {
231 u64 start = bre->start;
232 u64 len;
233
234 if (bre_end <= range->end)
235 len = bre->length;
236 else
237 len = range->start + range_len(range)
238 - bre->start;
239 __add_badblock_range(bb, start - range->start, len);
240 continue;
241 }
242 /*
243 * Deal with overlap for badrange starting before
244 * the namespace.
245 */
246 if (bre->start < range->start) {
247 u64 len;
248
249 if (bre_end < range->end)
250 len = bre->start + bre->length - range->start;
251 else
252 len = range_len(range);
253 __add_badblock_range(bb, 0, len);
254 }
255 }
256 }
257
258 /**
259 * nvdimm_badblocks_populate() - Convert a list of badranges to badblocks
260 * @region: parent region of the range to interrogate
261 * @bb: badblocks instance to populate
262 * @res: resource range to consider
263 *
264 * The badrange list generated during bus initialization may contain
265 * multiple, possibly overlapping physical address ranges. Compare each
266 * of these ranges to the resource range currently being initialized,
267 * and add badblocks entries for all matching sub-ranges
268 */
nvdimm_badblocks_populate(struct nd_region * nd_region,struct badblocks * bb,const struct range * range)269 void nvdimm_badblocks_populate(struct nd_region *nd_region,
270 struct badblocks *bb, const struct range *range)
271 {
272 struct nvdimm_bus *nvdimm_bus;
273
274 if (!is_memory(&nd_region->dev)) {
275 dev_WARN_ONCE(&nd_region->dev, 1,
276 "%s only valid for pmem regions\n", __func__);
277 return;
278 }
279 nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
280
281 nvdimm_bus_lock(&nvdimm_bus->dev);
282 badblocks_populate(&nvdimm_bus->badrange, bb, range);
283 nvdimm_bus_unlock(&nvdimm_bus->dev);
284 }
285 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);
286