xref: /openbmc/linux/drivers/nvdimm/btt_devs.c (revision 60772e48)
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 
24 static 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, "%s\n", __func__);
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 
36 static struct device_type nd_btt_device_type = {
37 	.name = "nd_btt",
38 	.release = nd_btt_release,
39 };
40 
41 bool is_nd_btt(struct device *dev)
42 {
43 	return dev->type == &nd_btt_device_type;
44 }
45 EXPORT_SYMBOL(is_nd_btt);
46 
47 struct 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 }
54 EXPORT_SYMBOL(to_nd_btt);
55 
56 static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
57 	4096, 4104, 4160, 4224, 0 };
58 
59 static 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 
67 static 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, "%s: result: %zd wrote: %s%s", __func__,
78 			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
79 	nvdimm_bus_unlock(dev);
80 	device_unlock(dev);
81 
82 	return rc ? rc : len;
83 }
84 static DEVICE_ATTR_RW(sector_size);
85 
86 static 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 
96 static 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, "%s: result: %zd wrote: %s%s", __func__,
105 			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
106 	device_unlock(dev);
107 
108 	return rc ? rc : len;
109 }
110 static DEVICE_ATTR_RW(uuid);
111 
112 static 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 
125 static 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, "%s: result: %zd wrote: %s%s", __func__,
135 			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
136 	nvdimm_bus_unlock(dev);
137 	device_unlock(dev);
138 
139 	return rc;
140 }
141 static DEVICE_ATTR_RW(namespace);
142 
143 static 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 }
160 static DEVICE_ATTR_RO(size);
161 
162 static struct attribute *nd_btt_attributes[] = {
163 	&dev_attr_sector_size.attr,
164 	&dev_attr_namespace.attr,
165 	&dev_attr_uuid.attr,
166 	&dev_attr_size.attr,
167 	NULL,
168 };
169 
170 static struct attribute_group nd_btt_attribute_group = {
171 	.attrs = nd_btt_attributes,
172 };
173 
174 static const struct attribute_group *nd_btt_attribute_groups[] = {
175 	&nd_btt_attribute_group,
176 	&nd_device_attribute_group,
177 	&nd_numa_attribute_group,
178 	NULL,
179 };
180 
181 static struct device *__nd_btt_create(struct nd_region *nd_region,
182 		unsigned long lbasize, u8 *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 		kfree(nd_btt);
195 		return NULL;
196 	}
197 
198 	nd_btt->lbasize = lbasize;
199 	if (uuid)
200 		uuid = kmemdup(uuid, 16, GFP_KERNEL);
201 	nd_btt->uuid = uuid;
202 	dev = &nd_btt->dev;
203 	dev_set_name(dev, "btt%d.%d", nd_region->id, nd_btt->id);
204 	dev->parent = &nd_region->dev;
205 	dev->type = &nd_btt_device_type;
206 	dev->groups = nd_btt_attribute_groups;
207 	device_initialize(&nd_btt->dev);
208 	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
209 		dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
210 				__func__, dev_name(ndns->claim));
211 		put_device(dev);
212 		return NULL;
213 	}
214 	return dev;
215 }
216 
217 struct device *nd_btt_create(struct nd_region *nd_region)
218 {
219 	struct device *dev = __nd_btt_create(nd_region, 0, NULL, NULL);
220 
221 	__nd_device_register(dev);
222 	return dev;
223 }
224 
225 /**
226  * nd_btt_arena_is_valid - check if the metadata layout is valid
227  * @nd_btt:	device with BTT geometry and backing device info
228  * @super:	pointer to the arena's info block being tested
229  *
230  * Check consistency of the btt info block with itself by validating
231  * the checksum, and with the parent namespace by verifying the
232  * parent_uuid contained in the info block with the one supplied in.
233  *
234  * Returns:
235  * false for an invalid info block, true for a valid one
236  */
237 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
238 {
239 	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
240 	u64 checksum;
241 
242 	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
243 		return false;
244 
245 	if (!guid_is_null((guid_t *)&super->parent_uuid))
246 		if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
247 			return false;
248 
249 	checksum = le64_to_cpu(super->checksum);
250 	super->checksum = 0;
251 	if (checksum != nd_sb_checksum((struct nd_gen_sb *) super))
252 		return false;
253 	super->checksum = cpu_to_le64(checksum);
254 
255 	/* TODO: figure out action for this */
256 	if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0)
257 		dev_info(&nd_btt->dev, "Found arena with an error flag\n");
258 
259 	return true;
260 }
261 EXPORT_SYMBOL(nd_btt_arena_is_valid);
262 
263 int nd_btt_version(struct nd_btt *nd_btt, struct nd_namespace_common *ndns,
264 		struct btt_sb *btt_sb)
265 {
266 	if (ndns->claim_class == NVDIMM_CCLASS_BTT2) {
267 		/* Probe/setup for BTT v2.0 */
268 		nd_btt->initial_offset = 0;
269 		nd_btt->version_major = 2;
270 		nd_btt->version_minor = 0;
271 		if (nvdimm_read_bytes(ndns, 0, btt_sb, sizeof(*btt_sb), 0))
272 			return -ENXIO;
273 		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
274 			return -ENODEV;
275 		if ((le16_to_cpu(btt_sb->version_major) != 2) ||
276 				(le16_to_cpu(btt_sb->version_minor) != 0))
277 			return -ENODEV;
278 	} else {
279 		/*
280 		 * Probe/setup for BTT v1.1 (NVDIMM_CCLASS_NONE or
281 		 * NVDIMM_CCLASS_BTT)
282 		 */
283 		nd_btt->initial_offset = SZ_4K;
284 		nd_btt->version_major = 1;
285 		nd_btt->version_minor = 1;
286 		if (nvdimm_read_bytes(ndns, SZ_4K, btt_sb, sizeof(*btt_sb), 0))
287 			return -ENXIO;
288 		if (!nd_btt_arena_is_valid(nd_btt, btt_sb))
289 			return -ENODEV;
290 		if ((le16_to_cpu(btt_sb->version_major) != 1) ||
291 				(le16_to_cpu(btt_sb->version_minor) != 1))
292 			return -ENODEV;
293 	}
294 	return 0;
295 }
296 EXPORT_SYMBOL(nd_btt_version);
297 
298 static int __nd_btt_probe(struct nd_btt *nd_btt,
299 		struct nd_namespace_common *ndns, struct btt_sb *btt_sb)
300 {
301 	int rc;
302 
303 	if (!btt_sb || !ndns || !nd_btt)
304 		return -ENODEV;
305 
306 	if (nvdimm_namespace_capacity(ndns) < SZ_16M)
307 		return -ENXIO;
308 
309 	rc = nd_btt_version(nd_btt, ndns, btt_sb);
310 	if (rc < 0)
311 		return rc;
312 
313 	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
314 	nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
315 	if (!nd_btt->uuid)
316 		return -ENOMEM;
317 
318 	__nd_device_register(&nd_btt->dev);
319 
320 	return 0;
321 }
322 
323 int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
324 {
325 	int rc;
326 	struct device *btt_dev;
327 	struct btt_sb *btt_sb;
328 	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
329 
330 	if (ndns->force_raw)
331 		return -ENODEV;
332 
333 	switch (ndns->claim_class) {
334 	case NVDIMM_CCLASS_NONE:
335 	case NVDIMM_CCLASS_BTT:
336 	case NVDIMM_CCLASS_BTT2:
337 		break;
338 	default:
339 		return -ENODEV;
340 	}
341 
342 	nvdimm_bus_lock(&ndns->dev);
343 	btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
344 	nvdimm_bus_unlock(&ndns->dev);
345 	if (!btt_dev)
346 		return -ENOMEM;
347 	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
348 	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
349 	dev_dbg(dev, "%s: btt: %s\n", __func__,
350 			rc == 0 ? dev_name(btt_dev) : "<none>");
351 	if (rc < 0) {
352 		struct nd_btt *nd_btt = to_nd_btt(btt_dev);
353 
354 		nd_detach_ndns(btt_dev, &nd_btt->ndns);
355 		put_device(btt_dev);
356 	}
357 
358 	return rc;
359 }
360 EXPORT_SYMBOL(nd_btt_probe);
361