Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[linux-2.6-microblaze.git] / drivers / nvdimm / badrange.c
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
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
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
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
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
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
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
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  */
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
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  */
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);