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 "nd-core.h"
16#include "pmem.h"
17#include "pfn.h"
18#include "btt.h"
19#include "nd.h"
20
21void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
22{
23 struct nd_namespace_common *ndns = *_ndns;
24 struct nvdimm_bus *nvdimm_bus;
25
26 if (!ndns)
27 return;
28
29 nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
30 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
31 dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
32 ndns->claim = NULL;
33 *_ndns = NULL;
34 put_device(&ndns->dev);
35}
36
37void nd_detach_ndns(struct device *dev,
38 struct nd_namespace_common **_ndns)
39{
40 struct nd_namespace_common *ndns = *_ndns;
41
42 if (!ndns)
43 return;
44 get_device(&ndns->dev);
45 nvdimm_bus_lock(&ndns->dev);
46 __nd_detach_ndns(dev, _ndns);
47 nvdimm_bus_unlock(&ndns->dev);
48 put_device(&ndns->dev);
49}
50
51bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
52 struct nd_namespace_common **_ndns)
53{
54 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
55
56 if (attach->claim)
57 return false;
58 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
59 dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
60 attach->claim = dev;
61 *_ndns = attach;
62 get_device(&attach->dev);
63 return true;
64}
65
66bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
67 struct nd_namespace_common **_ndns)
68{
69 bool claimed;
70
71 nvdimm_bus_lock(&attach->dev);
72 claimed = __nd_attach_ndns(dev, attach, _ndns);
73 nvdimm_bus_unlock(&attach->dev);
74 return claimed;
75}
76
77static int namespace_match(struct device *dev, void *data)
78{
79 char *name = data;
80
81 return strcmp(name, dev_name(dev)) == 0;
82}
83
84static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
85{
86 struct nd_region *nd_region = to_nd_region(dev->parent);
87 struct device *seed = NULL;
88
89 if (is_nd_btt(dev))
90 seed = nd_region->btt_seed;
91 else if (is_nd_pfn(dev))
92 seed = nd_region->pfn_seed;
93 else if (is_nd_dax(dev))
94 seed = nd_region->dax_seed;
95
96 if (seed == dev || ndns || dev->driver)
97 return false;
98 return true;
99}
100
101struct nd_pfn *to_nd_pfn_safe(struct device *dev)
102{
103 /*
104 * pfn device attributes are re-used by dax device instances, so we
105 * need to be careful to correct device-to-nd_pfn conversion.
106 */
107 if (is_nd_pfn(dev))
108 return to_nd_pfn(dev);
109
110 if (is_nd_dax(dev)) {
111 struct nd_dax *nd_dax = to_nd_dax(dev);
112
113 return &nd_dax->nd_pfn;
114 }
115
116 WARN_ON(1);
117 return NULL;
118}
119
120static void nd_detach_and_reset(struct device *dev,
121 struct nd_namespace_common **_ndns)
122{
123 /* detach the namespace and destroy / reset the device */
124 __nd_detach_ndns(dev, _ndns);
125 if (is_idle(dev, *_ndns)) {
126 nd_device_unregister(dev, ND_ASYNC);
127 } else if (is_nd_btt(dev)) {
128 struct nd_btt *nd_btt = to_nd_btt(dev);
129
130 nd_btt->lbasize = 0;
131 kfree(nd_btt->uuid);
132 nd_btt->uuid = NULL;
133 } else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
134 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
135
136 kfree(nd_pfn->uuid);
137 nd_pfn->uuid = NULL;
138 nd_pfn->mode = PFN_MODE_NONE;
139 }
140}
141
142ssize_t nd_namespace_store(struct device *dev,
143 struct nd_namespace_common **_ndns, const char *buf,
144 size_t len)
145{
146 struct nd_namespace_common *ndns;
147 struct device *found;
148 char *name;
149
150 if (dev->driver) {
151 dev_dbg(dev, "namespace already active\n");
152 return -EBUSY;
153 }
154
155 name = kstrndup(buf, len, GFP_KERNEL);
156 if (!name)
157 return -ENOMEM;
158 strim(name);
159
160 if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
161 /* pass */;
162 else {
163 len = -EINVAL;
164 goto out;
165 }
166
167 ndns = *_ndns;
168 if (strcmp(name, "") == 0) {
169 nd_detach_and_reset(dev, _ndns);
170 goto out;
171 } else if (ndns) {
172 dev_dbg(dev, "namespace already set to: %s\n",
173 dev_name(&ndns->dev));
174 len = -EBUSY;
175 goto out;
176 }
177
178 found = device_find_child(dev->parent, name, namespace_match);
179 if (!found) {
180 dev_dbg(dev, "'%s' not found under %s\n", name,
181 dev_name(dev->parent));
182 len = -ENODEV;
183 goto out;
184 }
185
186 ndns = to_ndns(found);
187
188 switch (ndns->claim_class) {
189 case NVDIMM_CCLASS_NONE:
190 break;
191 case NVDIMM_CCLASS_BTT:
192 case NVDIMM_CCLASS_BTT2:
193 if (!is_nd_btt(dev)) {
194 len = -EBUSY;
195 goto out_attach;
196 }
197 break;
198 case NVDIMM_CCLASS_PFN:
199 if (!is_nd_pfn(dev)) {
200 len = -EBUSY;
201 goto out_attach;
202 }
203 break;
204 case NVDIMM_CCLASS_DAX:
205 if (!is_nd_dax(dev)) {
206 len = -EBUSY;
207 goto out_attach;
208 }
209 break;
210 default:
211 len = -EBUSY;
212 goto out_attach;
213 break;
214 }
215
216 if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
217 dev_dbg(dev, "%s too small to host\n", name);
218 len = -ENXIO;
219 goto out_attach;
220 }
221
222 WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
223 if (!__nd_attach_ndns(dev, ndns, _ndns)) {
224 dev_dbg(dev, "%s already claimed\n",
225 dev_name(&ndns->dev));
226 len = -EBUSY;
227 }
228
229 out_attach:
230 put_device(&ndns->dev); /* from device_find_child */
231 out:
232 kfree(name);
233 return len;
234}
235
236/*
237 * nd_sb_checksum: compute checksum for a generic info block
238 *
239 * Returns a fletcher64 checksum of everything in the given info block
240 * except the last field (since that's where the checksum lives).
241 */
242u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
243{
244 u64 sum;
245 __le64 sum_save;
246
247 BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
248 BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
249 BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
250
251 sum_save = nd_gen_sb->checksum;
252 nd_gen_sb->checksum = 0;
253 sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
254 nd_gen_sb->checksum = sum_save;
255 return sum;
256}
257EXPORT_SYMBOL(nd_sb_checksum);
258
259static int nsio_rw_bytes(struct nd_namespace_common *ndns,
260 resource_size_t offset, void *buf, size_t size, int rw,
261 unsigned long flags)
262{
263 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
264 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
265 sector_t sector = offset >> 9;
266 int rc = 0;
267
268 if (unlikely(!size))
269 return 0;
270
271 if (unlikely(offset + size > nsio->size)) {
272 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
273 return -EFAULT;
274 }
275
276 if (rw == READ) {
277 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
278 return -EIO;
279 if (memcpy_mcsafe(buf, nsio->addr + offset, size) != 0)
280 return -EIO;
281 return 0;
282 }
283
284 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
285 if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
286 && !(flags & NVDIMM_IO_ATOMIC)) {
287 long cleared;
288
289 might_sleep();
290 cleared = nvdimm_clear_poison(&ndns->dev,
291 nsio->res.start + offset, size);
292 if (cleared < size)
293 rc = -EIO;
294 if (cleared > 0 && cleared / 512) {
295 cleared /= 512;
296 badblocks_clear(&nsio->bb, sector, cleared);
297 }
298 arch_invalidate_pmem(nsio->addr + offset, size);
299 } else
300 rc = -EIO;
301 }
302
303 memcpy_flushcache(nsio->addr + offset, buf, size);
304 nvdimm_flush(to_nd_region(ndns->dev.parent));
305
306 return rc;
307}
308
309int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)
310{
311 struct resource *res = &nsio->res;
312 struct nd_namespace_common *ndns = &nsio->common;
313
314 nsio->size = resource_size(res);
315 if (!devm_request_mem_region(dev, res->start, resource_size(res),
316 dev_name(&ndns->dev))) {
317 dev_warn(dev, "could not reserve region %pR\n", res);
318 return -EBUSY;
319 }
320
321 ndns->rw_bytes = nsio_rw_bytes;
322 if (devm_init_badblocks(dev, &nsio->bb))
323 return -ENOMEM;
324 nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
325 &nsio->res);
326
327 nsio->addr = devm_memremap(dev, res->start, resource_size(res),
328 ARCH_MEMREMAP_PMEM);
329
330 return PTR_ERR_OR_ZERO(nsio->addr);
331}
332EXPORT_SYMBOL_GPL(devm_nsio_enable);
333
334void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
335{
336 struct resource *res = &nsio->res;
337
338 devm_memunmap(dev, nsio->addr);
339 devm_exit_badblocks(dev, &nsio->bb);
340 devm_release_mem_region(dev, res->start, resource_size(res));
341}
342EXPORT_SYMBOL_GPL(devm_nsio_disable);
343