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 <linux/badblocks.h>
8 #include "nd-core.h"
9 #include "pmem.h"
10 #include "pfn.h"
11 #include "btt.h"
12 #include "nd.h"
13
__nd_detach_ndns(struct device * dev,struct nd_namespace_common ** _ndns)14 void __nd_detach_ndns(struct device *dev, struct nd_namespace_common **_ndns)
15 {
16 struct nd_namespace_common *ndns = *_ndns;
17 struct nvdimm_bus *nvdimm_bus;
18
19 if (!ndns)
20 return;
21
22 nvdimm_bus = walk_to_nvdimm_bus(&ndns->dev);
23 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
24 dev_WARN_ONCE(dev, ndns->claim != dev, "%s: invalid claim\n", __func__);
25 ndns->claim = NULL;
26 *_ndns = NULL;
27 put_device(&ndns->dev);
28 }
29
nd_detach_ndns(struct device * dev,struct nd_namespace_common ** _ndns)30 void nd_detach_ndns(struct device *dev,
31 struct nd_namespace_common **_ndns)
32 {
33 struct nd_namespace_common *ndns = *_ndns;
34
35 if (!ndns)
36 return;
37 get_device(&ndns->dev);
38 nvdimm_bus_lock(&ndns->dev);
39 __nd_detach_ndns(dev, _ndns);
40 nvdimm_bus_unlock(&ndns->dev);
41 put_device(&ndns->dev);
42 }
43
__nd_attach_ndns(struct device * dev,struct nd_namespace_common * attach,struct nd_namespace_common ** _ndns)44 bool __nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
45 struct nd_namespace_common **_ndns)
46 {
47 struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&attach->dev);
48
49 if (attach->claim)
50 return false;
51 lockdep_assert_held(&nvdimm_bus->reconfig_mutex);
52 dev_WARN_ONCE(dev, *_ndns, "%s: invalid claim\n", __func__);
53 attach->claim = dev;
54 *_ndns = attach;
55 get_device(&attach->dev);
56 return true;
57 }
58
nd_attach_ndns(struct device * dev,struct nd_namespace_common * attach,struct nd_namespace_common ** _ndns)59 bool nd_attach_ndns(struct device *dev, struct nd_namespace_common *attach,
60 struct nd_namespace_common **_ndns)
61 {
62 bool claimed;
63
64 nvdimm_bus_lock(&attach->dev);
65 claimed = __nd_attach_ndns(dev, attach, _ndns);
66 nvdimm_bus_unlock(&attach->dev);
67 return claimed;
68 }
69
namespace_match(struct device * dev,void * data)70 static int namespace_match(struct device *dev, void *data)
71 {
72 char *name = data;
73
74 return strcmp(name, dev_name(dev)) == 0;
75 }
76
is_idle(struct device * dev,struct nd_namespace_common * ndns)77 static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
78 {
79 struct nd_region *nd_region = to_nd_region(dev->parent);
80 struct device *seed = NULL;
81
82 if (is_nd_btt(dev))
83 seed = nd_region->btt_seed;
84 else if (is_nd_pfn(dev))
85 seed = nd_region->pfn_seed;
86 else if (is_nd_dax(dev))
87 seed = nd_region->dax_seed;
88
89 if (seed == dev || ndns || dev->driver)
90 return false;
91 return true;
92 }
93
to_nd_pfn_safe(struct device * dev)94 struct nd_pfn *to_nd_pfn_safe(struct device *dev)
95 {
96 /*
97 * pfn device attributes are re-used by dax device instances, so we
98 * need to be careful to correct device-to-nd_pfn conversion.
99 */
100 if (is_nd_pfn(dev))
101 return to_nd_pfn(dev);
102
103 if (is_nd_dax(dev)) {
104 struct nd_dax *nd_dax = to_nd_dax(dev);
105
106 return &nd_dax->nd_pfn;
107 }
108
109 WARN_ON(1);
110 return NULL;
111 }
112
nd_detach_and_reset(struct device * dev,struct nd_namespace_common ** _ndns)113 static void nd_detach_and_reset(struct device *dev,
114 struct nd_namespace_common **_ndns)
115 {
116 /* detach the namespace and destroy / reset the device */
117 __nd_detach_ndns(dev, _ndns);
118 if (is_idle(dev, *_ndns)) {
119 nd_device_unregister(dev, ND_ASYNC);
120 } else if (is_nd_btt(dev)) {
121 struct nd_btt *nd_btt = to_nd_btt(dev);
122
123 nd_btt->lbasize = 0;
124 kfree(nd_btt->uuid);
125 nd_btt->uuid = NULL;
126 } else if (is_nd_pfn(dev) || is_nd_dax(dev)) {
127 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
128
129 kfree(nd_pfn->uuid);
130 nd_pfn->uuid = NULL;
131 nd_pfn->mode = PFN_MODE_NONE;
132 }
133 }
134
nd_namespace_store(struct device * dev,struct nd_namespace_common ** _ndns,const char * buf,size_t len)135 ssize_t nd_namespace_store(struct device *dev,
136 struct nd_namespace_common **_ndns, const char *buf,
137 size_t len)
138 {
139 struct nd_namespace_common *ndns;
140 struct device *found;
141 char *name;
142
143 if (dev->driver) {
144 dev_dbg(dev, "namespace already active\n");
145 return -EBUSY;
146 }
147
148 name = kstrndup(buf, len, GFP_KERNEL);
149 if (!name)
150 return -ENOMEM;
151 strim(name);
152
153 if (strncmp(name, "namespace", 9) == 0 || strcmp(name, "") == 0)
154 /* pass */;
155 else {
156 len = -EINVAL;
157 goto out;
158 }
159
160 ndns = *_ndns;
161 if (strcmp(name, "") == 0) {
162 nd_detach_and_reset(dev, _ndns);
163 goto out;
164 } else if (ndns) {
165 dev_dbg(dev, "namespace already set to: %s\n",
166 dev_name(&ndns->dev));
167 len = -EBUSY;
168 goto out;
169 }
170
171 found = device_find_child(dev->parent, name, namespace_match);
172 if (!found) {
173 dev_dbg(dev, "'%s' not found under %s\n", name,
174 dev_name(dev->parent));
175 len = -ENODEV;
176 goto out;
177 }
178
179 ndns = to_ndns(found);
180
181 switch (ndns->claim_class) {
182 case NVDIMM_CCLASS_NONE:
183 break;
184 case NVDIMM_CCLASS_BTT:
185 case NVDIMM_CCLASS_BTT2:
186 if (!is_nd_btt(dev)) {
187 len = -EBUSY;
188 goto out_attach;
189 }
190 break;
191 case NVDIMM_CCLASS_PFN:
192 if (!is_nd_pfn(dev)) {
193 len = -EBUSY;
194 goto out_attach;
195 }
196 break;
197 case NVDIMM_CCLASS_DAX:
198 if (!is_nd_dax(dev)) {
199 len = -EBUSY;
200 goto out_attach;
201 }
202 break;
203 default:
204 len = -EBUSY;
205 goto out_attach;
206 break;
207 }
208
209 if (__nvdimm_namespace_capacity(ndns) < SZ_16M) {
210 dev_dbg(dev, "%s too small to host\n", name);
211 len = -ENXIO;
212 goto out_attach;
213 }
214
215 WARN_ON_ONCE(!is_nvdimm_bus_locked(dev));
216 if (!__nd_attach_ndns(dev, ndns, _ndns)) {
217 dev_dbg(dev, "%s already claimed\n",
218 dev_name(&ndns->dev));
219 len = -EBUSY;
220 }
221
222 out_attach:
223 put_device(&ndns->dev); /* from device_find_child */
224 out:
225 kfree(name);
226 return len;
227 }
228
229 /*
230 * nd_sb_checksum: compute checksum for a generic info block
231 *
232 * Returns a fletcher64 checksum of everything in the given info block
233 * except the last field (since that's where the checksum lives).
234 */
nd_sb_checksum(struct nd_gen_sb * nd_gen_sb)235 u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
236 {
237 u64 sum;
238 __le64 sum_save;
239
240 BUILD_BUG_ON(sizeof(struct btt_sb) != SZ_4K);
241 BUILD_BUG_ON(sizeof(struct nd_pfn_sb) != SZ_4K);
242 BUILD_BUG_ON(sizeof(struct nd_gen_sb) != SZ_4K);
243
244 sum_save = nd_gen_sb->checksum;
245 nd_gen_sb->checksum = 0;
246 sum = nd_fletcher64(nd_gen_sb, sizeof(*nd_gen_sb), 1);
247 nd_gen_sb->checksum = sum_save;
248 return sum;
249 }
250 EXPORT_SYMBOL(nd_sb_checksum);
251
nsio_rw_bytes(struct nd_namespace_common * ndns,resource_size_t offset,void * buf,size_t size,int rw,unsigned long flags)252 static int nsio_rw_bytes(struct nd_namespace_common *ndns,
253 resource_size_t offset, void *buf, size_t size, int rw,
254 unsigned long flags)
255 {
256 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
257 unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
258 sector_t sector = offset >> 9;
259 int rc = 0, ret = 0;
260
261 if (unlikely(!size))
262 return 0;
263
264 if (unlikely(offset + size > nsio->size)) {
265 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
266 return -EFAULT;
267 }
268
269 if (rw == READ) {
270 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align)))
271 return -EIO;
272 if (copy_mc_to_kernel(buf, nsio->addr + offset, size) != 0)
273 return -EIO;
274 return 0;
275 }
276
277 if (unlikely(is_bad_pmem(&nsio->bb, sector, sz_align))) {
278 if (IS_ALIGNED(offset, 512) && IS_ALIGNED(size, 512)
279 && !(flags & NVDIMM_IO_ATOMIC)) {
280 long cleared;
281
282 might_sleep();
283 cleared = nvdimm_clear_poison(&ndns->dev,
284 nsio->res.start + offset, size);
285 if (cleared < size)
286 rc = -EIO;
287 if (cleared > 0 && cleared / 512) {
288 cleared /= 512;
289 badblocks_clear(&nsio->bb, sector, cleared);
290 }
291 arch_invalidate_pmem(nsio->addr + offset, size);
292 } else
293 rc = -EIO;
294 }
295
296 memcpy_flushcache(nsio->addr + offset, buf, size);
297 ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
298 if (ret)
299 rc = ret;
300
301 return rc;
302 }
303
devm_nsio_enable(struct device * dev,struct nd_namespace_io * nsio,resource_size_t size)304 int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,
305 resource_size_t size)
306 {
307 struct nd_namespace_common *ndns = &nsio->common;
308 struct range range = {
309 .start = nsio->res.start,
310 .end = nsio->res.end,
311 };
312
313 nsio->size = size;
314 if (!devm_request_mem_region(dev, range.start, size,
315 dev_name(&ndns->dev))) {
316 dev_warn(dev, "could not reserve region %pR\n", &nsio->res);
317 return -EBUSY;
318 }
319
320 ndns->rw_bytes = nsio_rw_bytes;
321 if (devm_init_badblocks(dev, &nsio->bb))
322 return -ENOMEM;
323 nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
324 &range);
325
326 nsio->addr = devm_memremap(dev, range.start, size, ARCH_MEMREMAP_PMEM);
327
328 return PTR_ERR_OR_ZERO(nsio->addr);
329 }
330
devm_nsio_disable(struct device * dev,struct nd_namespace_io * nsio)331 void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
332 {
333 struct resource *res = &nsio->res;
334
335 devm_memunmap(dev, nsio->addr);
336 devm_exit_badblocks(dev, &nsio->bb);
337 devm_release_mem_region(dev, res->start, nsio->size);
338 }
339