xref: /openbmc/linux/drivers/nvdimm/claim.c (revision 5ae96d77)
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