1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4 */
5 #include <linux/device.h>
6 #include <linux/sizes.h>
7 #include "nd-core.h"
8 #include "pmem.h"
9 #include "pfn.h"
10 #include "btt.h"
11 #include "nd.h"
12
__nd_detach_ndns(struct device * dev,struct nd_namespace_common ** _ndns)13 void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
14 {
15 struct nd_namespace_common *ndns = *_ndns;
16 struct nvdimm_bus *nvdimm_bus;
17
18 if (!ndns)
19 return;
20
21 nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
22 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
23 dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
24 ndns->claim = NULL;
25 *_ndns = NULL;
26 put_device(&ndns->dev);
27 }
28
nd_detach_ndns(struct device * dev,struct nd_namespace_common ** _ndns)29 void nd_detach_ndns(struct device *dev,
30 struct nd_namespace_common **_ndns)
31 {
32 struct nd_namespace_common *ndns = *_ndns;
33
34 if (!ndns)
35 return;
36 get_device(&ndns->dev);
37 nvdimm_bus_lock(&ndns->dev);
38 __nd_detach_ndns(dev, _ndns);
39 nvdimm_bus_unlock(&ndns->dev);
40 put_device(&ndns->dev);
41 }
42
__nd_attach_ndns(struct device * dev,struct nd_namespace_common * attach,struct nd_namespace_common ** _ndns)43 bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
44 struct nd_namespace_common **_ndns)
45 {
46 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
47
48 if (attach->claim)
49 return false;
50 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
51 dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
52 attach->claim = dev;
53 *_ndns = attach;
54 get_device(&attach->dev);
55 return true;
56 }
57
nd_attach_ndns(struct device * dev,struct nd_namespace_common * attach,struct nd_namespace_common ** _ndns)58 bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
59 struct nd_namespace_common **_ndns)
60 {
61 bool claimed;
62
63 nvdimm_bus_lock(&attach->dev);
64 claimed = __nd_attach_ndns(dev, attach, _ndns);
65 nvdimm_bus_unlock(&attach->dev);
66 return claimed;
67 }
68
namespace_match(struct device * dev,void * data)69 static int namespace_match(struct device *dev, void *data)
70 {
71 char *name = data;
72
73 return strcmp(name, dev_name(dev)) == 0;
74 }
75
is_idle(struct device * dev,struct nd_namespace_common * ndns)76 static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
77 {
78 struct nd_region *nd_region = to_nd_region(dev->parent);
79 struct device *seed = NULL;
80
81 if (is_nd_btt(dev))
82 seed = nd_region->btt_seed;
83 else if (is_nd_pfn(dev))
84 seed = nd_region->pfn_seed;
85 else if (is_nd_dax(dev))
86 seed = nd_region->dax_seed;
87
88 if (seed == dev || ndns || dev->driver)
89 return false;
90 return true;
91 }
92
to_nd_pfn_safe(struct device * dev)93 struct nd_pfn *to_nd_pfn_safe(struct device *dev)
94 {
95 /*
96 * pfn device attributes are re-used by dax device instances, so we
97 * need to be careful to correct device-to-nd_pfn conversion.
98 */
99 if (is_nd_pfn(dev))
100 return to_nd_pfn(dev);
101
102 if (is_nd_dax(dev)) {
103 struct nd_dax *nd_dax = to_nd_dax(dev);
104
105 return &nd_dax->nd_pfn;
106 }
107
108 WARN_ON(1);
109 return NULL;
110 }
111
nd_detach_and_reset(struct device * dev,struct nd_namespace_common ** _ndns)112 static void nd_detach_and_reset(struct device *dev,
113 struct nd_namespace_common **_ndns)
114 {
115 /* detach the namespace and destroy / reset the device */
116 __nd_detach_ndns(dev, _ndns);
117 if (is_idle(dev, *_ndns)) {
118 nd_device_unregister(dev, ND_ASYNC);
119 } else if (is_nd_btt(dev)) {
120 struct nd_btt *nd_btt = to_nd_btt(dev);
121
122 nd_btt->lbasize = 0;
123 kfree(nd_btt->uuid);
124 nd_btt->uuid = NULL;
125 } else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
126 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
127
128 kfree(nd_pfn->uuid);
129 nd_pfn->uuid = NULL;
130 nd_pfn->mode = PFN_MODE_NONE;
131 }
132 }
133
nd_namespace_store(struct device * dev,struct nd_namespace_common ** _ndns,const char * buf,size_t len)134 ssize_t nd_namespace_store(struct device *dev,
135 struct nd_namespace_common **_ndns, const char *buf,
136 size_t len)
137 {
138 struct nd_namespace_common *ndns;
139 struct device *found;
140 char *name;
141
142 if (dev->driver) {
143 dev_dbg(dev, "namespace already active\n");
144 return -EBUSY;
145 }
146
147 name = kstrndup(buf, len, GFP_KERNEL);
148 if (!name)
149 return -ENOMEM;
150 strim(name);
151
152 if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
153 /* pass */;
154 else {
155 len = -EINVAL;
156 goto out;
157 }
158
159 ndns = *_ndns;
160 if (strcmp(name, "") == 0) {
161 nd_detach_and_reset(dev, _ndns);
162 goto out;
163 } else if (ndns) {
164 dev_dbg(dev, "namespace already set to: %s\n",
165 dev_name(&ndns->dev));
166 len = -EBUSY;
167 goto out;
168 }
169
170 found = device_find_child(dev->parent, name, namespace_match);
171 if (!found) {
172 dev_dbg(dev, "'%s' not found under %s\n", name,
173 dev_name(dev->parent));
174 len = -ENODEV;
175 goto out;
176 }
177
178 ndns = to_ndns(found);
179
180 switch (ndns->claim_class) {
181 case NVDIMM_CCLASS_NONE:
182 break;
183 case NVDIMM_CCLASS_BTT:
184 case NVDIMM_CCLASS_BTT2:
185 if (!is_nd_btt(dev)) {
186 len = -EBUSY;
187 goto out_attach;
188 }
189 break;
190 case NVDIMM_CCLASS_PFN:
191 if (!is_nd_pfn(dev)) {
192 len = -EBUSY;
193 goto out_attach;
194 }
195 break;
196 case NVDIMM_CCLASS_DAX:
197 if (!is_nd_dax(dev)) {
198 len = -EBUSY;
199 goto out_attach;
200 }
201 break;
202 default:
203 len = -EBUSY;
204 goto out_attach;
205 break;
206 }
207
208 if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
209 dev_dbg(dev, "%s too small to host\n", name);
210 len = -ENXIO;
211 goto out_attach;
212 }
213
214 WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
215 if (!__nd_attach_ndns(dev, ndns, _ndns)) {
216 dev_dbg(dev, "%s already claimed\n",
217 dev_name(&ndns->dev));
218 len = -EBUSY;
219 }
220
221 out_attach:
222 put_device(&ndns->dev); /* from device_find_child */
223 out:
224 kfree(name);
225 return len;
226 }
227
228 /*
229 * nd_sb_checksum: compute checksum for a generic info block
230 *
231 * Returns a fletcher64 checksum of everything in the given info block
232 * except the last field (since that's where the checksum lives).
233 */
nd_sb_checksum(struct nd_gen_sb * nd_gen_sb)234 u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
235 {
236 u64 sum;
237 __le64 sum_save;
238
239 BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
240 BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
241 BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
242
243 sum_save = nd_gen_sb->checksum;
244 nd_gen_sb->checksum = 0;
245 sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
246 nd_gen_sb->checksum = sum_save;
247 return sum;
248 }
249 EXPORT_SYMBOL(nd_sb_checksum);
250
nsio_rw_bytes(struct nd_namespace_common * ndns,resource_size_t offset,void * buf,size_t size,int rw,unsigned long flags)251 static int nsio_rw_bytes(struct nd_namespace_common *ndns,
252 resource_size_t offset, void *buf, size_t size, int rw,
253 unsigned long flags)
254 {
255 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
256 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
257 sector_t sector = offset >> 9;
258 int rc = 0, ret = 0;
259
260 if (unlikely(!size))
261 return 0;
262
263 if (unlikely(offset + size > nsio->size)) {
264 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
265 return -EFAULT;
266 }
267
268 if (rw == READ) {
269 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
270 return -EIO;
271 if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
272 return -EIO;
273 return 0;
274 }
275
276 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
277 if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
278 && !(flags & NVDIMM_IO_ATOMIC)) {
279 long cleared;
280
281 might_sleep();
282 cleared = nvdimm_clear_poison(&ndns->dev,
283 nsio->res.start + offset, size);
284 if (cleared < size)
285 rc = -EIO;
286 if (cleared > 0 && cleared / 512) {
287 cleared /= 512;
288 badblocks_clear(&nsio->bb, sector, cleared);
289 }
290 arch_invalidate_pmem(nsio->addr + offset, size);
291 } else
292 rc = -EIO;
293 }
294
295 memcpy_flushcache(nsio->addr + offset, buf, size);
296 ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
297 if (ret)
298 rc = ret;
299
300 return rc;
301 }
302
devm_nsio_enable(struct device * dev,struct nd_namespace_io * nsio,resource_size_t size)303 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
304 resource_size_t size)
305 {
306 struct nd_namespace_common *ndns = &nsio->common;
307 struct range range = {
308 .start = nsio->res.start,
309 .end = nsio->res.end,
310 };
311
312 nsio->size = size;
313 if (!devm_request_mem_region(dev, range.start, size,
314 dev_name(&ndns->dev))) {
315 dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
316 return -EBUSY;
317 }
318
319 ndns->rw_bytes = nsio_rw_bytes;
320 if (devm_init_badblocks(dev, &nsio->bb))
321 return -ENOMEM;
322 nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
323 &range);
324
325 nsio->addr = devm_memremap(dev, range.start, size, ARCH_MEMREMAP_PMEM);
326
327 return PTR_ERR_OR_ZERO(nsio->addr);
328 }
329
devm_nsio_disable(struct device * dev,struct nd_namespace_io * nsio)330 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
331 {
332 struct resource *res = &nsio->res;
333
334 devm_memunmap(dev, nsio->addr);
335 devm_exit_badblocks(dev, &nsio->bb);
336 devm_release_mem_region(dev, res->start, nsio->size);
337 }
338