claim.c

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