xref: /openbmc/linux/drivers/nvdimm/btt_devs.c (revision e52a6321)
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/genhd.h>
8 #include <linux/sizes.h>
9 #include <linux/slab.h>
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include "nd-core.h"
13 #include "btt.h"
14 #include "nd.h"
15 
16 static void nd_btt_release(struct device *dev)
17 {
18 	struct nd_region *nd_region = to_nd_region(dev->parent);
19 	struct nd_btt *nd_btt = to_nd_btt(dev);
20 
21 	dev_dbg(dev, "trace\n");
22 	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
23 	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
24 	kfree(nd_btt->uuid);
25 	kfree(nd_btt);
26 }
27 
28 static struct device_type nd_btt_device_type = {
29 	.name = "nd_btt",
30 	.release = nd_btt_release,
31 };
32 
33 bool is_nd_btt(struct device *dev)
34 {
35 	return dev->type == &nd_btt_device_type;
36 }
37 EXPORT_SYMBOL(is_nd_btt);
38 
39 struct nd_btt *to_nd_btt(struct device *dev)
40 {
41 	struct nd_btt *nd_btt = container_of(dev, struct nd_btt, dev);
42 
43 	WARN_ON(!is_nd_btt(dev));
44 	return nd_btt;
45 }
46 EXPORT_SYMBOL(to_nd_btt);
47 
48 static const unsigned long btt_lbasize_supported[] = { 512, 520, 528,
49 	4096, 4104, 4160, 4224, 0 };
50 
51 static ssize_t sector_size_show(struct device *dev,
52 		struct device_attribute *attr, char *buf)
53 {
54 	struct nd_btt *nd_btt = to_nd_btt(dev);
55 
56 	return nd_size_select_show(nd_btt->lbasize, btt_lbasize_supported, buf);
57 }
58 
59 static ssize_t sector_size_store(struct device *dev,
60 		struct device_attribute *attr, const char *buf, size_t len)
61 {
62 	struct nd_btt *nd_btt = to_nd_btt(dev);
63 	ssize_t rc;
64 
65 	nd_device_lock(dev);
66 	nvdimm_bus_lock(dev);
67 	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
68 			btt_lbasize_supported);
69 	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
70 			buf[len - 1] == '\n' ? "" : "\n");
71 	nvdimm_bus_unlock(dev);
72 	nd_device_unlock(dev);
73 
74 	return rc ? rc : len;
75 }
76 static DEVICE_ATTR_RW(sector_size);
77 
78 static ssize_t uuid_show(struct device *dev,
79 		struct device_attribute *attr, char *buf)
80 {
81 	struct nd_btt *nd_btt = to_nd_btt(dev);
82 
83 	if (nd_btt->uuid)
84 		return sprintf(buf, "%pUb\n", nd_btt->uuid);
85 	return sprintf(buf, "\n");
86 }
87 
88 static ssize_t uuid_store(struct device *dev,
89 		struct device_attribute *attr, const char *buf, size_t len)
90 {
91 	struct nd_btt *nd_btt = to_nd_btt(dev);
92 	ssize_t rc;
93 
94 	nd_device_lock(dev);
95 	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
96 	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
97 			buf[len - 1] == '\n' ? "" : "\n");
98 	nd_device_unlock(dev);
99 
100 	return rc ? rc : len;
101 }
102 static DEVICE_ATTR_RW(uuid);
103 
104 static ssize_t namespace_show(struct device *dev,
105 		struct device_attribute *attr, char *buf)
106 {
107 	struct nd_btt *nd_btt = to_nd_btt(dev);
108 	ssize_t rc;
109 
110 	nvdimm_bus_lock(dev);
111 	rc = sprintf(buf, "%s\n", nd_btt->ndns
112 			? dev_name(&nd_btt->ndns->dev) : "");
113 	nvdimm_bus_unlock(dev);
114 	return rc;
115 }
116 
117 static ssize_t namespace_store(struct device *dev,
118 		struct device_attribute *attr, const char *buf, size_t len)
119 {
120 	struct nd_btt *nd_btt = to_nd_btt(dev);
121 	ssize_t rc;
122 
123 	nd_device_lock(dev);
124 	nvdimm_bus_lock(dev);
125 	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
126 	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
127 			buf[len - 1] == '\n' ? "" : "\n");
128 	nvdimm_bus_unlock(dev);
129 	nd_device_unlock(dev);
130 
131 	return rc;
132 }
133 static DEVICE_ATTR_RW(namespace);
134 
135 static ssize_t size_show(struct device *dev,
136 		struct device_attribute *attr, char *buf)
137 {
138 	struct nd_btt *nd_btt = to_nd_btt(dev);
139 	ssize_t rc;
140 
141 	nd_device_lock(dev);
142 	if (dev->driver)
143 		rc = sprintf(buf, "%llu\n", nd_btt->size);
144 	else {
145 		/* no size to convey if the btt instance is disabled */
146 		rc = -ENXIO;
147 	}
148 	nd_device_unlock(dev);
149 
150 	return rc;
151 }
152 static DEVICE_ATTR_RO(size);
153 
154 static ssize_t log_zero_flags_show(struct device *dev,
155 		struct device_attribute *attr, char *buf)
156 {
157 	return sprintf(buf, "Y\n");
158 }
159 static DEVICE_ATTR_RO(log_zero_flags);
160 
161 static struct attribute *nd_btt_attributes[] = {
162 	&dev_attr_sector_size.attr,
163 	&dev_attr_namespace.attr,
164 	&dev_attr_uuid.attr,
165 	&dev_attr_size.attr,
166 	&dev_attr_log_zero_flags.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 		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 	dev->groups = nd_btt_attribute_groups;
208 	device_initialize(&nd_btt->dev);
209 	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
210 		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
211 				dev_name(ndns->claim));
212 		put_device(dev);
213 		return NULL;
214 	}
215 	return dev;
216 
217 out_put_id:
218 	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
219 
220 out_nd_btt:
221 	kfree(nd_btt);
222 	return NULL;
223 }
224 
225 struct 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  */
245 bool 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 }
269 EXPORT_SYMBOL(nd_btt_arena_is_valid);
270 
271 int 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 }
304 EXPORT_SYMBOL(nd_btt_version);
305 
306 static 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 
331 int 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 }
367 EXPORT_SYMBOL(nd_btt_probe);
368