1/*
2 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 */
13#include <linux/blkdev.h>
14#include <linux/device.h>
15#include <linux/genhd.h>
16#include <linux/sizes.h>
17#include <linux/slab.h>
18#include <linux/fs.h>
19#include <linux/mm.h>
20#include "nd-core.h"
21#include "btt.h"
22#include "nd.h"
23
24static void nd_btt_release(struct device *dev)
25{
26 struct nd_region *nd_region = to_nd_region(dev->parent);
27 struct nd_btt *nd_btt = to_nd_btt(dev);
28
29 dev_dbg(dev, "trace\n");
30 nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
31 ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
32 kfree(nd_btt->uuid);
33 kfree(nd_btt);
34}
35
36static struct device_type nd_btt_device_type = {
37 .name = "nd_btt",
38 .release = nd_btt_release,
39};
40
41bool is_nd_btt(struct device *dev)
42{
43 return dev->type == &nd_btt_device_type;
44}
45EXPORT_SYMBOL(is_nd_btt);
46
47struct nd_btt *to_nd_btt(struct device *dev)
48{
49 struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
50
51 WARN_ON(!is_nd_btt(dev));
52 return nd_btt;
53}
54EXPORT_SYMBOL(to_nd_btt);
55
56static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
57 4096, 4104, 4160, 4224, 0 };
58
59static ssize_t sector_size_show(struct device *dev,
60 struct device_attribute *attr, char *buf)
61{
62 struct nd_btt *nd_btt = to_nd_btt(dev);
63
64 return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
65}
66
67static ssize_t sector_size_store(struct device *dev,
68 struct device_attribute *attr, const char *buf, size_t len)
69{
70 struct nd_btt *nd_btt = to_nd_btt(dev);
71 ssize_t rc;
72
73 device_lock(dev);
74 nvdimm_bus_lock(dev);
75 rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
76 btt_lbasize_supported);
77 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
78 buf[len - 1] == '\n' ? "" : "\n");
79 nvdimm_bus_unlock(dev);
80 device_unlock(dev);
81
82 return rc ? rc : len;
83}
84static DEVICE_ATTR_RW(sector_size);
85
86static ssize_t uuid_show(struct device *dev,
87 struct device_attribute *attr, char *buf)
88{
89 struct nd_btt *nd_btt = to_nd_btt(dev);
90
91 if (nd_btt->uuid)
92 return sprintf(buf, "%pUb\n", nd_btt->uuid);
93 return sprintf(buf, "\n");
94}
95
96static ssize_t uuid_store(struct device *dev,
97 struct device_attribute *attr, const char *buf, size_t len)
98{
99 struct nd_btt *nd_btt = to_nd_btt(dev);
100 ssize_t rc;
101
102 device_lock(dev);
103 rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
104 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
105 buf[len - 1] == '\n' ? "" : "\n");
106 device_unlock(dev);
107
108 return rc ? rc : len;
109}
110static DEVICE_ATTR_RW(uuid);
111
112static ssize_t namespace_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
114{
115 struct nd_btt *nd_btt = to_nd_btt(dev);
116 ssize_t rc;
117
118 nvdimm_bus_lock(dev);
119 rc = sprintf(buf, "%s\n", nd_btt->ndns
120 ? dev_name(&nd_btt->ndns->dev) : "");
121 nvdimm_bus_unlock(dev);
122 return rc;
123}
124
125static ssize_t namespace_store(struct device *dev,
126 struct device_attribute *attr, const char *buf, size_t len)
127{
128 struct nd_btt *nd_btt = to_nd_btt(dev);
129 ssize_t rc;
130
131 device_lock(dev);
132 nvdimm_bus_lock(dev);
133 rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
134 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
135 buf[len - 1] == '\n' ? "" : "\n");
136 nvdimm_bus_unlock(dev);
137 device_unlock(dev);
138
139 return rc;
140}
141static DEVICE_ATTR_RW(namespace);
142
143static ssize_t size_show(struct device *dev,
144 struct device_attribute *attr, char *buf)
145{
146 struct nd_btt *nd_btt = to_nd_btt(dev);
147 ssize_t rc;
148
149 device_lock(dev);
150 if (dev->driver)
151 rc = sprintf(buf, "%llu\n", nd_btt->size);
152 else {
153 /* no size to convey if the btt instance is disabled */
154 rc = -ENXIO;
155 }
156 device_unlock(dev);
157
158 return rc;
159}
160static DEVICE_ATTR_RO(size);
161
162static ssize_t log_zero_flags_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
164{
165 return sprintf(buf, "Y\n");
166}
167static DEVICE_ATTR_RO(log_zero_flags);
168
169static struct attribute *nd_btt_attributes[] = {
170 &dev_attr_sector_size.attr,
171 &dev_attr_namespace.attr,
172 &dev_attr_uuid.attr,
173 &dev_attr_size.attr,
174 &dev_attr_log_zero_flags.attr,
175 NULL,
176};
177
178static struct attribute_group nd_btt_attribute_group = {
179 .attrs = nd_btt_attributes,
180};
181
182static const struct attribute_group *nd_btt_attribute_groups[] = {
183 &nd_btt_attribute_group,
184 &nd_device_attribute_group,
185 &nd_numa_attribute_group,
186 NULL,
187};
188
189static struct device *__nd_btt_create(struct nd_region *nd_region,
190 unsigned long lbasize, u8 *uuid,
191 struct nd_namespace_common *ndns)
192{
193 struct nd_btt *nd_btt;
194 struct device *dev;
195
196 nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
197 if (!nd_btt)
198 return NULL;
199
200 nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
201 if (nd_btt->id < 0) {
202 kfree(nd_btt);
203 return NULL;
204 }
205
206 nd_btt->lbasize = lbasize;
207 if (uuid)
208 uuid = kmemdup(uuid, 16, GFP_KERNEL);
209 nd_btt->uuid = uuid;
210 dev = &nd_btt->dev;
211 dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
212 dev->parent = &nd_region->dev;
213 dev->type = &nd_btt_device_type;
214 dev->groups = nd_btt_attribute_groups;
215 device_initialize(&nd_btt->dev);
216 if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
217 dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
218 dev_name(ndns->claim));
219 put_device(dev);
220 return NULL;
221 }
222 return dev;
223}
224
225struct device *nd_btt_create(struct nd_region *nd_region)
226{
227 struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
228
229 __nd_device_register(dev);
230 return dev;
231}
232
233/**
234 * nd_btt_arena_is_valid - check if the metadata layout is valid
235 * @nd_btt: device with BTT geometry and backing device info
236 * @super: pointer to the arena's info block being tested
237 *
238 * Check consistency of the btt info block with itself by validating
239 * the checksum, and with the parent namespace by verifying the
240 * parent_uuid contained in the info block with the one supplied in.
241 *
242 * Returns:
243 * false for an invalid info block, true for a valid one
244 */
245bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
246{
247 const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
248 u64 checksum;
249
250 if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
251 return false;
252
253 if (!guid_is_null((guid_t *)&super->parent_uuid))
254 if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
255 return false;
256
257 checksum = le64_to_cpu(super->checksum);
258 super->checksum = 0;
259 if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
260 return false;
261 super->checksum = cpu_to_le64(checksum);
262
263 /* TODO: figure out action for this */
264 if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
265 dev_info(&nd_btt->dev, "Found arena with an error flag\n");
266
267 return true;
268}
269EXPORT_SYMBOL(nd_btt_arena_is_valid);
270
271int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
272 struct btt_sb *btt_sb)
273{
274 if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
275 /* Probe/setup for BTT v2.0 */
276 nd_btt->initial_offset = 0;
277 nd_btt->version_major = 2;
278 nd_btt->version_minor = 0;
279 if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
280 return -ENXIO;
281 if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
282 return -ENODEV;
283 if ((le16_to_cpu(btt_sb->version_major) != 2) ||
284 (le16_to_cpu(btt_sb->version_minor) != 0))
285 return -ENODEV;
286 } else {
287 /*
288 * Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
289 * NVDIMM_CCLASS_BTT)
290 */
291 nd_btt->initial_offset = SZ_4K;
292 nd_btt->version_major = 1;
293 nd_btt->version_minor = 1;
294 if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
295 return -ENXIO;
296 if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
297 return -ENODEV;
298 if ((le16_to_cpu(btt_sb->version_major) != 1) ||
299 (le16_to_cpu(btt_sb->version_minor) != 1))
300 return -ENODEV;
301 }
302 return 0;
303}
304EXPORT_SYMBOL(nd_btt_version);
305
306static int __nd_btt_probe(struct nd_btt *nd_btt,
307 struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
308{
309 int rc;
310
311 if (!btt_sb || !ndns || !nd_btt)
312 return -ENODEV;
313
314 if (nvdimm_namespace_capacity(ndns) < SZ_16M)
315 return -ENXIO;
316
317 rc = nd_btt_version(nd_btt, ndns, btt_sb);
318 if (rc < 0)
319 return rc;
320
321 nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
322 nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
323 if (!nd_btt->uuid)
324 return -ENOMEM;
325
326 __nd_device_register(&nd_btt->dev);
327
328 return 0;
329}
330
331int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
332{
333 int rc;
334 struct device *btt_dev;
335 struct btt_sb *btt_sb;
336 struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
337
338 if (ndns->force_raw)
339 return -ENODEV;
340
341 switch (ndns->claim_class) {
342 case NVDIMM_CCLASS_NONE:
343 case NVDIMM_CCLASS_BTT:
344 case NVDIMM_CCLASS_BTT2:
345 break;
346 default:
347 return -ENODEV;
348 }
349
350 nvdimm_bus_lock(&ndns->dev);
351 btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
352 nvdimm_bus_unlock(&ndns->dev);
353 if (!btt_dev)
354 return -ENOMEM;
355 btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
356 rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
357 dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
358 if (rc < 0) {
359 struct nd_btt *nd_btt = to_nd_btt(btt_dev);
360
361 nd_detach_ndns(btt_dev, &nd_btt->ndns);
362 put_device(btt_dev);
363 }
364
365 return rc;
366}
367EXPORT_SYMBOL(nd_btt_probe);
368