xref: /kernel/linux/linux-5.10/drivers/nvdimm/claim.c (revision 8c2ecf20) 
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
13void __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
29void 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
43bool __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
58bool 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
69static int namespace_match(struct device *dev, void *data)
70{
71	char *name = data;
72
73	return strcmp(name, dev_name(dev)) == 0;
74}
75
76static 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
93struct 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
112static 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
134ssize_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 */
234u64 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}
249EXPORT_SYMBOL(nd_sb_checksum);
250
251static 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
303int 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
330void 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