xref: /openbmc/linux/drivers/nvdimm/btt_devs.c (revision d5771670)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4  */
5 #include <linux/blkdev.h>
6 #include <linux/device.h>
7 #include <linux/sizes.h>
8 #include <linux/slab.h>
9 #include <linux/fs.h>
10 #include <linux/mm.h>
11 #include "nd-core.h"
12 #include "btt.h"
13 #include "nd.h"
14 
15 static void nd_btt_release(struct device *dev)
16 {
17 	struct nd_region *nd_region = to_nd_region(dev->parent);
18 	struct nd_btt *nd_btt = to_nd_btt(dev);
19 
20 	dev_dbg(dev, "trace\n");
21 	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
22 	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
23 	kfree(nd_btt->uuid);
24 	kfree(nd_btt);
25 }
26 
27 struct nd_btt *to_nd_btt(struct device *dev)
28 {
29 	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
30 
31 	WARN_ON(!is_nd_btt(dev));
32 	return nd_btt;
33 }
34 EXPORT_SYMBOL(to_nd_btt);
35 
36 static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
37 	4096, 4104, 4160, 4224, 0 };
38 
39 static ssize_t sector_size_show(struct device *dev,
40 		struct device_attribute *attr, char *buf)
41 {
42 	struct nd_btt *nd_btt = to_nd_btt(dev);
43 
44 	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
45 }
46 
47 static ssize_t sector_size_store(struct device *dev,
48 		struct device_attribute *attr, const char *buf, size_t len)
49 {
50 	struct nd_btt *nd_btt = to_nd_btt(dev);
51 	ssize_t rc;
52 
53 	nd_device_lock(dev);
54 	nvdimm_bus_lock(dev);
55 	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
56 			btt_lbasize_supported);
57 	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
58 			buf[len - 1] == '\n' ? "" : "\n");
59 	nvdimm_bus_unlock(dev);
60 	nd_device_unlock(dev);
61 
62 	return rc ? rc : len;
63 }
64 static DEVICE_ATTR_RW(sector_size);
65 
66 static ssize_t uuid_show(struct device *dev,
67 		struct device_attribute *attr, char *buf)
68 {
69 	struct nd_btt *nd_btt = to_nd_btt(dev);
70 
71 	if (nd_btt->uuid)
72 		return sprintf(buf, "%pUb\n", nd_btt->uuid);
73 	return sprintf(buf, "\n");
74 }
75 
76 static ssize_t uuid_store(struct device *dev,
77 		struct device_attribute *attr, const char *buf, size_t len)
78 {
79 	struct nd_btt *nd_btt = to_nd_btt(dev);
80 	ssize_t rc;
81 
82 	nd_device_lock(dev);
83 	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
84 	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
85 			buf[len - 1] == '\n' ? "" : "\n");
86 	nd_device_unlock(dev);
87 
88 	return rc ? rc : len;
89 }
90 static DEVICE_ATTR_RW(uuid);
91 
92 static ssize_t namespace_show(struct device *dev,
93 		struct device_attribute *attr, char *buf)
94 {
95 	struct nd_btt *nd_btt = to_nd_btt(dev);
96 	ssize_t rc;
97 
98 	nvdimm_bus_lock(dev);
99 	rc = sprintf(buf, "%s\n", nd_btt->ndns
100 			? dev_name(&nd_btt->ndns->dev) : "");
101 	nvdimm_bus_unlock(dev);
102 	return rc;
103 }
104 
105 static ssize_t namespace_store(struct device *dev,
106 		struct device_attribute *attr, const char *buf, size_t len)
107 {
108 	struct nd_btt *nd_btt = to_nd_btt(dev);
109 	ssize_t rc;
110 
111 	nd_device_lock(dev);
112 	nvdimm_bus_lock(dev);
113 	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
114 	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
115 			buf[len - 1] == '\n' ? "" : "\n");
116 	nvdimm_bus_unlock(dev);
117 	nd_device_unlock(dev);
118 
119 	return rc;
120 }
121 static DEVICE_ATTR_RW(namespace);
122 
123 static ssize_t size_show(struct device *dev,
124 		struct device_attribute *attr, char *buf)
125 {
126 	struct nd_btt *nd_btt = to_nd_btt(dev);
127 	ssize_t rc;
128 
129 	nd_device_lock(dev);
130 	if (dev->driver)
131 		rc = sprintf(buf, "%llu\n", nd_btt->size);
132 	else {
133 		/* no size to convey if the btt instance is disabled */
134 		rc = -ENXIO;
135 	}
136 	nd_device_unlock(dev);
137 
138 	return rc;
139 }
140 static DEVICE_ATTR_RO(size);
141 
142 static ssize_t log_zero_flags_show(struct device *dev,
143 		struct device_attribute *attr, char *buf)
144 {
145 	return sprintf(buf, "Y\n");
146 }
147 static DEVICE_ATTR_RO(log_zero_flags);
148 
149 static struct attribute *nd_btt_attributes[] = {
150 	&dev_attr_sector_size.attr,
151 	&dev_attr_namespace.attr,
152 	&dev_attr_uuid.attr,
153 	&dev_attr_size.attr,
154 	&dev_attr_log_zero_flags.attr,
155 	NULL,
156 };
157 
158 static struct attribute_group nd_btt_attribute_group = {
159 	.attrs = nd_btt_attributes,
160 };
161 
162 static const struct attribute_group *nd_btt_attribute_groups[] = {
163 	&nd_btt_attribute_group,
164 	&nd_device_attribute_group,
165 	&nd_numa_attribute_group,
166 	NULL,
167 };
168 
169 static const struct device_type nd_btt_device_type = {
170 	.name = "nd_btt",
171 	.release = nd_btt_release,
172 	.groups = nd_btt_attribute_groups,
173 };
174 
175 bool is_nd_btt(struct device *dev)
176 {
177 	return dev->type == &nd_btt_device_type;
178 }
179 EXPORT_SYMBOL(is_nd_btt);
180 
181 static struct device *__nd_btt_create(struct nd_region *nd_region,
182 				      unsigned long lbasize, uuid_t *uuid,
183 				      struct nd_namespace_common *ndns)
184 {
185 	struct nd_btt *nd_btt;
186 	struct device *dev;
187 
188 	nd_btt = kzalloc(sizeof(*nd_btt), GFP_KERNEL);
189 	if (!nd_btt)
190 		return NULL;
191 
192 	nd_btt->id = ida_simple_get(&nd_region->btt_ida, 0, 0, GFP_KERNEL);
193 	if (nd_btt->id < 0)
194 		goto out_nd_btt;
195 
196 	nd_btt->lbasize = lbasize;
197 	if (uuid) {
198 		uuid = kmemdup(uuid, 16, GFP_KERNEL);
199 		if (!uuid)
200 			goto out_put_id;
201 	}
202 	nd_btt->uuid = uuid;
203 	dev = &nd_btt->dev;
204 	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
205 	dev->parent = &nd_region->dev;
206 	dev->type = &nd_btt_device_type;
207 	device_initialize(&nd_btt->dev);
208 	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
209 		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
210 				dev_name(ndns->claim));
211 		put_device(dev);
212 		return NULL;
213 	}
214 	return dev;
215 
216 out_put_id:
217 	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
218 
219 out_nd_btt:
220 	kfree(nd_btt);
221 	return NULL;
222 }
223 
224 struct device *nd_btt_create(struct nd_region *nd_region)
225 {
226 	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
227 
228 	__nd_device_register(dev);
229 	return dev;
230 }
231 
232 /**
233  * nd_btt_arena_is_valid - check if the metadata layout is valid
234  * @nd_btt:	device with BTT geometry and backing device info
235  * @super:	pointer to the arena's info block being tested
236  *
237  * Check consistency of the btt info block with itself by validating
238  * the checksum, and with the parent namespace by verifying the
239  * parent_uuid contained in the info block with the one supplied in.
240  *
241  * Returns:
242  * false for an invalid info block, true for a valid one
243  */
244 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
245 {
246 	const uuid_t *ns_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
247 	uuid_t parent_uuid;
248 	u64 checksum;
249 
250 	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
251 		return false;
252 
253 	import_uuid(&parent_uuid, super->parent_uuid);
254 	if (!uuid_is_null(&parent_uuid))
255 		if (!uuid_equal(&parent_uuid, ns_uuid))
256 			return false;
257 
258 	checksum = le64_to_cpu(super->checksum);
259 	super->checksum = 0;
260 	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
261 		return false;
262 	super->checksum = cpu_to_le64(checksum);
263 
264 	/* TODO: figure out action for this */
265 	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
266 		dev_info(&nd_btt->dev, "Found arena with an error flag\n");
267 
268 	return true;
269 }
270 EXPORT_SYMBOL(nd_btt_arena_is_valid);
271 
272 int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
273 		struct btt_sb *btt_sb)
274 {
275 	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
276 		/* Probe/setup for BTT v2.0 */
277 		nd_btt->initial_offset = 0;
278 		nd_btt->version_major = 2;
279 		nd_btt->version_minor = 0;
280 		if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
281 			return -ENXIO;
282 		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
283 			return -ENODEV;
284 		if ((le16_to_cpu(btt_sb->version_major) != 2) ||
285 				(le16_to_cpu(btt_sb->version_minor) != 0))
286 			return -ENODEV;
287 	} else {
288 		/*
289 		 * Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
290 		 * NVDIMM_CCLASS_BTT)
291 		 */
292 		nd_btt->initial_offset = SZ_4K;
293 		nd_btt->version_major = 1;
294 		nd_btt->version_minor = 1;
295 		if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
296 			return -ENXIO;
297 		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
298 			return -ENODEV;
299 		if ((le16_to_cpu(btt_sb->version_major) != 1) ||
300 				(le16_to_cpu(btt_sb->version_minor) != 1))
301 			return -ENODEV;
302 	}
303 	return 0;
304 }
305 EXPORT_SYMBOL(nd_btt_version);
306 
307 static int __nd_btt_probe(struct nd_btt *nd_btt,
308 		struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
309 {
310 	int rc;
311 
312 	if (!btt_sb || !ndns || !nd_btt)
313 		return -ENODEV;
314 
315 	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
316 		return -ENXIO;
317 
318 	rc = nd_btt_version(nd_btt, ndns, btt_sb);
319 	if (rc < 0)
320 		return rc;
321 
322 	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
323 	nd_btt->uuid = kmemdup(&btt_sb->uuid, sizeof(uuid_t), GFP_KERNEL);
324 	if (!nd_btt->uuid)
325 		return -ENOMEM;
326 
327 	__nd_device_register(&nd_btt->dev);
328 
329 	return 0;
330 }
331 
332 int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
333 {
334 	int rc;
335 	struct device *btt_dev;
336 	struct btt_sb *btt_sb;
337 	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
338 
339 	if (ndns->force_raw)
340 		return -ENODEV;
341 
342 	switch (ndns->claim_class) {
343 	case NVDIMM_CCLASS_NONE:
344 	case NVDIMM_CCLASS_BTT:
345 	case NVDIMM_CCLASS_BTT2:
346 		break;
347 	default:
348 		return -ENODEV;
349 	}
350 
351 	nvdimm_bus_lock(&ndns->dev);
352 	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
353 	nvdimm_bus_unlock(&ndns->dev);
354 	if (!btt_dev)
355 		return -ENOMEM;
356 	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
357 	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
358 	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
359 	if (rc < 0) {
360 		struct nd_btt *nd_btt = to_nd_btt(btt_dev);
361 
362 		nd_detach_ndns(btt_dev, &nd_btt->ndns);
363 		put_device(btt_dev);
364 	}
365 
366 	return rc;
367 }
368 EXPORT_SYMBOL(nd_btt_probe);
369