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/device.h>
14 #include <linux/sizes.h>
15 #include <linux/pmem.h>
16 #include "nd-core.h"
17 #include "pfn.h"
18 #include "btt.h"
19 #include "nd.h"
20
__nd_detach_ndns(struct device * dev,struct nd_namespace_common ** _ndns)21 void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
22 {
23 struct nd_namespace_common *ndns = *_ndns;
24
25 dev_WARN_ONCE(dev, !mutex_is_locked(&ndns->dev.mutex)
26 || ndns->claim != dev,
27 "%s: invalid claim\n", __func__);
28 ndns->claim = NULL;
29 *_ndns = NULL;
30 put_device(&ndns->dev);
31 }
32
nd_detach_ndns(struct device * dev,struct nd_namespace_common ** _ndns)33 void nd_detach_ndns(struct device *dev,
34 struct nd_namespace_common **_ndns)
35 {
36 struct nd_namespace_common *ndns = *_ndns;
37
38 if (!ndns)
39 return;
40 get_device(&ndns->dev);
41 device_lock(&ndns->dev);
42 __nd_detach_ndns(dev, _ndns);
43 device_unlock(&ndns->dev);
44 put_device(&ndns->dev);
45 }
46
__nd_attach_ndns(struct device * dev,struct nd_namespace_common * attach,struct nd_namespace_common ** _ndns)47 bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
48 struct nd_namespace_common **_ndns)
49 {
50 if (attach->claim)
51 return false;
52 dev_WARN_ONCE(dev, !mutex_is_locked(&attach->dev.mutex)
53 || *_ndns,
54 "%s: invalid claim\n", __func__);
55 attach->claim = dev;
56 *_ndns = attach;
57 get_device(&attach->dev);
58 return true;
59 }
60
nd_attach_ndns(struct device * dev,struct nd_namespace_common * attach,struct nd_namespace_common ** _ndns)61 bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
62 struct nd_namespace_common **_ndns)
63 {
64 bool claimed;
65
66 device_lock(&attach->dev);
67 claimed = __nd_attach_ndns(dev, attach, _ndns);
68 device_unlock(&attach->dev);
69 return claimed;
70 }
71
namespace_match(struct device * dev,void * data)72 static int namespace_match(struct device *dev, void *data)
73 {
74 char *name = data;
75
76 return strcmp(name, dev_name(dev)) == 0;
77 }
78
is_idle(struct device * dev,struct nd_namespace_common * ndns)79 static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
80 {
81 struct nd_region *nd_region = to_nd_region(dev->parent);
82 struct device *seed = NULL;
83
84 if (is_nd_btt(dev))
85 seed = nd_region->btt_seed;
86 else if (is_nd_pfn(dev))
87 seed = nd_region->pfn_seed;
88 else if (is_nd_dax(dev))
89 seed = nd_region->dax_seed;
90
91 if (seed == dev || ndns || dev->driver)
92 return false;
93 return true;
94 }
95
to_nd_pfn_safe(struct device * dev)96 struct nd_pfn *to_nd_pfn_safe(struct device *dev)
97 {
98 /*
99 * pfn device attributes are re-used by dax device instances, so we
100 * need to be careful to correct device-to-nd_pfn conversion.
101 */
102 if (is_nd_pfn(dev))
103 return to_nd_pfn(dev);
104
105 if (is_nd_dax(dev)) {
106 struct nd_dax *nd_dax = to_nd_dax(dev);
107
108 return &nd_dax->nd_pfn;
109 }
110
111 WARN_ON(1);
112 return NULL;
113 }
114
nd_detach_and_reset(struct device * dev,struct nd_namespace_common ** _ndns)115 static void nd_detach_and_reset(struct device *dev,
116 struct nd_namespace_common **_ndns)
117 {
118 /* detach the namespace and destroy / reset the device */
119 nd_detach_ndns(dev, _ndns);
120 if (is_idle(dev, *_ndns)) {
121 nd_device_unregister(dev, ND_ASYNC);
122 } else if (is_nd_btt(dev)) {
123 struct nd_btt *nd_btt = to_nd_btt(dev);
124
125 nd_btt->lbasize = 0;
126 kfree(nd_btt->uuid);
127 nd_btt->uuid = NULL;
128 } else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
129 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
130
131 kfree(nd_pfn->uuid);
132 nd_pfn->uuid = NULL;
133 nd_pfn->mode = PFN_MODE_NONE;
134 }
135 }
136
nd_namespace_store(struct device * dev,struct nd_namespace_common ** _ndns,const char * buf,size_t len)137 ssize_t nd_namespace_store(struct device *dev,
138 struct nd_namespace_common **_ndns, const char *buf,
139 size_t len)
140 {
141 struct nd_namespace_common *ndns;
142 struct device *found;
143 char *name;
144
145 if (dev->driver) {
146 dev_dbg(dev, "%s: -EBUSY\n", __func__);
147 return -EBUSY;
148 }
149
150 name = kstrndup(buf, len, GFP_KERNEL);
151 if (!name)
152 return -ENOMEM;
153 strim(name);
154
155 if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
156 /* pass */;
157 else {
158 len = -EINVAL;
159 goto out;
160 }
161
162 ndns = *_ndns;
163 if (strcmp(name, "") == 0) {
164 nd_detach_and_reset(dev, _ndns);
165 goto out;
166 } else if (ndns) {
167 dev_dbg(dev, "namespace already set to: %s\n",
168 dev_name(&ndns->dev));
169 len = -EBUSY;
170 goto out;
171 }
172
173 found = device_find_child(dev->parent, name, namespace_match);
174 if (!found) {
175 dev_dbg(dev, "'%s' not found under %s\n", name,
176 dev_name(dev->parent));
177 len = -ENODEV;
178 goto out;
179 }
180
181 ndns = to_ndns(found);
182 if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
183 dev_dbg(dev, "%s too small to host\n", name);
184 len = -ENXIO;
185 goto out_attach;
186 }
187
188 WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
189 if (!nd_attach_ndns(dev, ndns, _ndns)) {
190 dev_dbg(dev, "%s already claimed\n",
191 dev_name(&ndns->dev));
192 len = -EBUSY;
193 }
194
195 out_attach:
196 put_device(&ndns->dev); /* from device_find_child */
197 out:
198 kfree(name);
199 return len;
200 }
201
202 /*
203 * nd_sb_checksum: compute checksum for a generic info block
204 *
205 * Returns a fletcher64 checksum of everything in the given info block
206 * except the last field (since that's where the checksum lives).
207 */
nd_sb_checksum(struct nd_gen_sb * nd_gen_sb)208 u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
209 {
210 u64 sum;
211 __le64 sum_save;
212
213 BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
214 BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
215 BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
216
217 sum_save = nd_gen_sb->checksum;
218 nd_gen_sb->checksum = 0;
219 sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
220 nd_gen_sb->checksum = sum_save;
221 return sum;
222 }
223 EXPORT_SYMBOL(nd_sb_checksum);
224
nsio_rw_bytes(struct nd_namespace_common * ndns,resource_size_t offset,void * buf,size_t size,int rw)225 static int nsio_rw_bytes(struct nd_namespace_common *ndns,
226 resource_size_t offset, void *buf, size_t size, int rw)
227 {
228 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
229
230 if (unlikely(offset + size > nsio->size)) {
231 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
232 return -EFAULT;
233 }
234
235 if (rw == READ) {
236 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
237
238 if (unlikely(is_bad_pmem(&nsio->bb, offset / 512, sz_align)))
239 return -EIO;
240 return memcpy_from_pmem(buf, nsio->addr + offset, size);
241 } else {
242 memcpy_to_pmem(nsio->addr + offset, buf, size);
243 nvdimm_flush(to_nd_region(ndns->dev.parent));
244 }
245
246 return 0;
247 }
248
devm_nsio_enable(struct device * dev,struct nd_namespace_io * nsio)249 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)
250 {
251 struct resource *res = &nsio->res;
252 struct nd_namespace_common *ndns = &nsio->common;
253
254 nsio->size = resource_size(res);
255 if (!devm_request_mem_region(dev, res->start, resource_size(res),
256 dev_name(dev))) {
257 dev_warn(dev, "could not reserve region %pR\n", res);
258 return -EBUSY;
259 }
260
261 ndns->rw_bytes = nsio_rw_bytes;
262 if (devm_init_badblocks(dev, &nsio->bb))
263 return -ENOMEM;
264 nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
265 &nsio->res);
266
267 nsio->addr = devm_memremap(dev, res->start, resource_size(res),
268 ARCH_MEMREMAP_PMEM);
269
270 return PTR_ERR_OR_ZERO(nsio->addr);
271 }
272 EXPORT_SYMBOL_GPL(devm_nsio_enable);
273
devm_nsio_disable(struct device * dev,struct nd_namespace_io * nsio)274 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
275 {
276 struct resource *res = &nsio->res;
277
278 devm_memunmap(dev, nsio->addr);
279 devm_exit_badblocks(dev, &nsio->bb);
280 devm_release_mem_region(dev, res->start, resource_size(res));
281 }
282 EXPORT_SYMBOL_GPL(devm_nsio_disable);
283