xref: /openbmc/linux/drivers/nvdimm/bus.c (revision 4d88a97aa9e8cfa6460aab119c5da60ad2267423)
1 /*
2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  */
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/vmalloc.h>
15 #include <linux/uaccess.h>
16 #include <linux/fcntl.h>
17 #include <linux/async.h>
18 #include <linux/ndctl.h>
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/fs.h>
22 #include <linux/io.h>
23 #include <linux/mm.h>
24 #include <linux/nd.h>
25 #include "nd-core.h"
26 #include "nd.h"
27 
28 int nvdimm_major;
29 static int nvdimm_bus_major;
30 static struct class *nd_class;
31 
32 static int to_nd_device_type(struct device *dev)
33 {
34 	if (is_nvdimm(dev))
35 		return ND_DEVICE_DIMM;
36 
37 	return 0;
38 }
39 
40 static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
41 {
42 	return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
43 			to_nd_device_type(dev));
44 }
45 
46 static int nvdimm_bus_match(struct device *dev, struct device_driver *drv)
47 {
48 	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
49 
50 	return test_bit(to_nd_device_type(dev), &nd_drv->type);
51 }
52 
53 static int nvdimm_bus_probe(struct device *dev)
54 {
55 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
56 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
57 	int rc;
58 
59 	rc = nd_drv->probe(dev);
60 	dev_dbg(&nvdimm_bus->dev, "%s.probe(%s) = %d\n", dev->driver->name,
61 			dev_name(dev), rc);
62 	return rc;
63 }
64 
65 static int nvdimm_bus_remove(struct device *dev)
66 {
67 	struct nd_device_driver *nd_drv = to_nd_device_driver(dev->driver);
68 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
69 	int rc;
70 
71 	rc = nd_drv->remove(dev);
72 	dev_dbg(&nvdimm_bus->dev, "%s.remove(%s) = %d\n", dev->driver->name,
73 			dev_name(dev), rc);
74 	return rc;
75 }
76 
77 static struct bus_type nvdimm_bus_type = {
78 	.name = "nd",
79 	.uevent = nvdimm_bus_uevent,
80 	.match = nvdimm_bus_match,
81 	.probe = nvdimm_bus_probe,
82 	.remove = nvdimm_bus_remove,
83 };
84 
85 static ASYNC_DOMAIN_EXCLUSIVE(nd_async_domain);
86 
87 void nd_synchronize(void)
88 {
89 	async_synchronize_full_domain(&nd_async_domain);
90 }
91 EXPORT_SYMBOL_GPL(nd_synchronize);
92 
93 static void nd_async_device_register(void *d, async_cookie_t cookie)
94 {
95 	struct device *dev = d;
96 
97 	if (device_add(dev) != 0) {
98 		dev_err(dev, "%s: failed\n", __func__);
99 		put_device(dev);
100 	}
101 	put_device(dev);
102 }
103 
104 static void nd_async_device_unregister(void *d, async_cookie_t cookie)
105 {
106 	struct device *dev = d;
107 
108 	device_unregister(dev);
109 	put_device(dev);
110 }
111 
112 void nd_device_register(struct device *dev)
113 {
114 	dev->bus = &nvdimm_bus_type;
115 	device_initialize(dev);
116 	get_device(dev);
117 	async_schedule_domain(nd_async_device_register, dev,
118 			&nd_async_domain);
119 }
120 EXPORT_SYMBOL(nd_device_register);
121 
122 void nd_device_unregister(struct device *dev, enum nd_async_mode mode)
123 {
124 	switch (mode) {
125 	case ND_ASYNC:
126 		get_device(dev);
127 		async_schedule_domain(nd_async_device_unregister, dev,
128 				&nd_async_domain);
129 		break;
130 	case ND_SYNC:
131 		nd_synchronize();
132 		device_unregister(dev);
133 		break;
134 	}
135 }
136 EXPORT_SYMBOL(nd_device_unregister);
137 
138 /**
139  * __nd_driver_register() - register a region or a namespace driver
140  * @nd_drv: driver to register
141  * @owner: automatically set by nd_driver_register() macro
142  * @mod_name: automatically set by nd_driver_register() macro
143  */
144 int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
145 		const char *mod_name)
146 {
147 	struct device_driver *drv = &nd_drv->drv;
148 
149 	if (!nd_drv->type) {
150 		pr_debug("driver type bitmask not set (%pf)\n",
151 				__builtin_return_address(0));
152 		return -EINVAL;
153 	}
154 
155 	if (!nd_drv->probe || !nd_drv->remove) {
156 		pr_debug("->probe() and ->remove() must be specified\n");
157 		return -EINVAL;
158 	}
159 
160 	drv->bus = &nvdimm_bus_type;
161 	drv->owner = owner;
162 	drv->mod_name = mod_name;
163 
164 	return driver_register(drv);
165 }
166 EXPORT_SYMBOL(__nd_driver_register);
167 
168 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
169 		char *buf)
170 {
171 	return sprintf(buf, ND_DEVICE_MODALIAS_FMT "\n",
172 			to_nd_device_type(dev));
173 }
174 static DEVICE_ATTR_RO(modalias);
175 
176 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
177 		char *buf)
178 {
179 	return sprintf(buf, "%s\n", dev->type->name);
180 }
181 static DEVICE_ATTR_RO(devtype);
182 
183 static struct attribute *nd_device_attributes[] = {
184 	&dev_attr_modalias.attr,
185 	&dev_attr_devtype.attr,
186 	NULL,
187 };
188 
189 /**
190  * nd_device_attribute_group - generic attributes for all devices on an nd bus
191  */
192 struct attribute_group nd_device_attribute_group = {
193 	.attrs = nd_device_attributes,
194 };
195 EXPORT_SYMBOL_GPL(nd_device_attribute_group);
196 
197 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
198 {
199 	dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
200 	struct device *dev;
201 
202 	dev = device_create(nd_class, &nvdimm_bus->dev, devt, nvdimm_bus,
203 			"ndctl%d", nvdimm_bus->id);
204 
205 	if (IS_ERR(dev)) {
206 		dev_dbg(&nvdimm_bus->dev, "failed to register ndctl%d: %ld\n",
207 				nvdimm_bus->id, PTR_ERR(dev));
208 		return PTR_ERR(dev);
209 	}
210 	return 0;
211 }
212 
213 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
214 {
215 	device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
216 }
217 
218 static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
219 	[ND_CMD_IMPLEMENTED] = { },
220 	[ND_CMD_SMART] = {
221 		.out_num = 2,
222 		.out_sizes = { 4, 8, },
223 	},
224 	[ND_CMD_SMART_THRESHOLD] = {
225 		.out_num = 2,
226 		.out_sizes = { 4, 8, },
227 	},
228 	[ND_CMD_DIMM_FLAGS] = {
229 		.out_num = 2,
230 		.out_sizes = { 4, 4 },
231 	},
232 	[ND_CMD_GET_CONFIG_SIZE] = {
233 		.out_num = 3,
234 		.out_sizes = { 4, 4, 4, },
235 	},
236 	[ND_CMD_GET_CONFIG_DATA] = {
237 		.in_num = 2,
238 		.in_sizes = { 4, 4, },
239 		.out_num = 2,
240 		.out_sizes = { 4, UINT_MAX, },
241 	},
242 	[ND_CMD_SET_CONFIG_DATA] = {
243 		.in_num = 3,
244 		.in_sizes = { 4, 4, UINT_MAX, },
245 		.out_num = 1,
246 		.out_sizes = { 4, },
247 	},
248 	[ND_CMD_VENDOR] = {
249 		.in_num = 3,
250 		.in_sizes = { 4, 4, UINT_MAX, },
251 		.out_num = 3,
252 		.out_sizes = { 4, 4, UINT_MAX, },
253 	},
254 };
255 
256 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd)
257 {
258 	if (cmd < ARRAY_SIZE(__nd_cmd_dimm_descs))
259 		return &__nd_cmd_dimm_descs[cmd];
260 	return NULL;
261 }
262 EXPORT_SYMBOL_GPL(nd_cmd_dimm_desc);
263 
264 static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
265 	[ND_CMD_IMPLEMENTED] = { },
266 	[ND_CMD_ARS_CAP] = {
267 		.in_num = 2,
268 		.in_sizes = { 8, 8, },
269 		.out_num = 2,
270 		.out_sizes = { 4, 4, },
271 	},
272 	[ND_CMD_ARS_START] = {
273 		.in_num = 4,
274 		.in_sizes = { 8, 8, 2, 6, },
275 		.out_num = 1,
276 		.out_sizes = { 4, },
277 	},
278 	[ND_CMD_ARS_STATUS] = {
279 		.out_num = 2,
280 		.out_sizes = { 4, UINT_MAX, },
281 	},
282 };
283 
284 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
285 {
286 	if (cmd < ARRAY_SIZE(__nd_cmd_bus_descs))
287 		return &__nd_cmd_bus_descs[cmd];
288 	return NULL;
289 }
290 EXPORT_SYMBOL_GPL(nd_cmd_bus_desc);
291 
292 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
293 		const struct nd_cmd_desc *desc, int idx, void *buf)
294 {
295 	if (idx >= desc->in_num)
296 		return UINT_MAX;
297 
298 	if (desc->in_sizes[idx] < UINT_MAX)
299 		return desc->in_sizes[idx];
300 
301 	if (nvdimm && cmd == ND_CMD_SET_CONFIG_DATA && idx == 2) {
302 		struct nd_cmd_set_config_hdr *hdr = buf;
303 
304 		return hdr->in_length;
305 	} else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2) {
306 		struct nd_cmd_vendor_hdr *hdr = buf;
307 
308 		return hdr->in_length;
309 	}
310 
311 	return UINT_MAX;
312 }
313 EXPORT_SYMBOL_GPL(nd_cmd_in_size);
314 
315 u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
316 		const struct nd_cmd_desc *desc, int idx, const u32 *in_field,
317 		const u32 *out_field)
318 {
319 	if (idx >= desc->out_num)
320 		return UINT_MAX;
321 
322 	if (desc->out_sizes[idx] < UINT_MAX)
323 		return desc->out_sizes[idx];
324 
325 	if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && idx == 1)
326 		return in_field[1];
327 	else if (nvdimm && cmd == ND_CMD_VENDOR && idx == 2)
328 		return out_field[1];
329 	else if (!nvdimm && cmd == ND_CMD_ARS_STATUS && idx == 1)
330 		return ND_CMD_ARS_STATUS_MAX;
331 
332 	return UINT_MAX;
333 }
334 EXPORT_SYMBOL_GPL(nd_cmd_out_size);
335 
336 static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
337 		int read_only, unsigned int ioctl_cmd, unsigned long arg)
338 {
339 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
340 	size_t buf_len = 0, in_len = 0, out_len = 0;
341 	static char out_env[ND_CMD_MAX_ENVELOPE];
342 	static char in_env[ND_CMD_MAX_ENVELOPE];
343 	const struct nd_cmd_desc *desc = NULL;
344 	unsigned int cmd = _IOC_NR(ioctl_cmd);
345 	void __user *p = (void __user *) arg;
346 	struct device *dev = &nvdimm_bus->dev;
347 	const char *cmd_name, *dimm_name;
348 	unsigned long dsm_mask;
349 	void *buf;
350 	int rc, i;
351 
352 	if (nvdimm) {
353 		desc = nd_cmd_dimm_desc(cmd);
354 		cmd_name = nvdimm_cmd_name(cmd);
355 		dsm_mask = nvdimm->dsm_mask ? *(nvdimm->dsm_mask) : 0;
356 		dimm_name = dev_name(&nvdimm->dev);
357 	} else {
358 		desc = nd_cmd_bus_desc(cmd);
359 		cmd_name = nvdimm_bus_cmd_name(cmd);
360 		dsm_mask = nd_desc->dsm_mask;
361 		dimm_name = "bus";
362 	}
363 
364 	if (!desc || (desc->out_num + desc->in_num == 0) ||
365 			!test_bit(cmd, &dsm_mask))
366 		return -ENOTTY;
367 
368 	/* fail write commands (when read-only) */
369 	if (read_only)
370 		switch (ioctl_cmd) {
371 		case ND_IOCTL_VENDOR:
372 		case ND_IOCTL_SET_CONFIG_DATA:
373 		case ND_IOCTL_ARS_START:
374 			dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
375 					nvdimm ? nvdimm_cmd_name(cmd)
376 					: nvdimm_bus_cmd_name(cmd));
377 			return -EPERM;
378 		default:
379 			break;
380 		}
381 
382 	/* process an input envelope */
383 	for (i = 0; i < desc->in_num; i++) {
384 		u32 in_size, copy;
385 
386 		in_size = nd_cmd_in_size(nvdimm, cmd, desc, i, in_env);
387 		if (in_size == UINT_MAX) {
388 			dev_err(dev, "%s:%s unknown input size cmd: %s field: %d\n",
389 					__func__, dimm_name, cmd_name, i);
390 			return -ENXIO;
391 		}
392 		if (!access_ok(VERIFY_READ, p + in_len, in_size))
393 			return -EFAULT;
394 		if (in_len < sizeof(in_env))
395 			copy = min_t(u32, sizeof(in_env) - in_len, in_size);
396 		else
397 			copy = 0;
398 		if (copy && copy_from_user(&in_env[in_len], p + in_len, copy))
399 			return -EFAULT;
400 		in_len += in_size;
401 	}
402 
403 	/* process an output envelope */
404 	for (i = 0; i < desc->out_num; i++) {
405 		u32 out_size = nd_cmd_out_size(nvdimm, cmd, desc, i,
406 				(u32 *) in_env, (u32 *) out_env);
407 		u32 copy;
408 
409 		if (out_size == UINT_MAX) {
410 			dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
411 					__func__, dimm_name, cmd_name, i);
412 			return -EFAULT;
413 		}
414 		if (!access_ok(VERIFY_WRITE, p + in_len + out_len, out_size))
415 			return -EFAULT;
416 		if (out_len < sizeof(out_env))
417 			copy = min_t(u32, sizeof(out_env) - out_len, out_size);
418 		else
419 			copy = 0;
420 		if (copy && copy_from_user(&out_env[out_len],
421 					p + in_len + out_len, copy))
422 			return -EFAULT;
423 		out_len += out_size;
424 	}
425 
426 	buf_len = out_len + in_len;
427 	if (!access_ok(VERIFY_WRITE, p, sizeof(buf_len)))
428 		return -EFAULT;
429 
430 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
431 		dev_dbg(dev, "%s:%s cmd: %s buf_len: %zu > %d\n", __func__,
432 				dimm_name, cmd_name, buf_len,
433 				ND_IOCTL_MAX_BUFLEN);
434 		return -EINVAL;
435 	}
436 
437 	buf = vmalloc(buf_len);
438 	if (!buf)
439 		return -ENOMEM;
440 
441 	if (copy_from_user(buf, p, buf_len)) {
442 		rc = -EFAULT;
443 		goto out;
444 	}
445 
446 	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
447 	if (rc < 0)
448 		goto out;
449 	if (copy_to_user(p, buf, buf_len))
450 		rc = -EFAULT;
451  out:
452 	vfree(buf);
453 	return rc;
454 }
455 
456 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
457 {
458 	long id = (long) file->private_data;
459 	int rc = -ENXIO, read_only;
460 	struct nvdimm_bus *nvdimm_bus;
461 
462 	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
463 	mutex_lock(&nvdimm_bus_list_mutex);
464 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
465 		if (nvdimm_bus->id == id) {
466 			rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
467 			break;
468 		}
469 	}
470 	mutex_unlock(&nvdimm_bus_list_mutex);
471 
472 	return rc;
473 }
474 
475 static int match_dimm(struct device *dev, void *data)
476 {
477 	long id = (long) data;
478 
479 	if (is_nvdimm(dev)) {
480 		struct nvdimm *nvdimm = to_nvdimm(dev);
481 
482 		return nvdimm->id == id;
483 	}
484 
485 	return 0;
486 }
487 
488 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
489 {
490 	int rc = -ENXIO, read_only;
491 	struct nvdimm_bus *nvdimm_bus;
492 
493 	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
494 	mutex_lock(&nvdimm_bus_list_mutex);
495 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
496 		struct device *dev = device_find_child(&nvdimm_bus->dev,
497 				file->private_data, match_dimm);
498 		struct nvdimm *nvdimm;
499 
500 		if (!dev)
501 			continue;
502 
503 		nvdimm = to_nvdimm(dev);
504 		rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
505 		put_device(dev);
506 		break;
507 	}
508 	mutex_unlock(&nvdimm_bus_list_mutex);
509 
510 	return rc;
511 }
512 
513 static int nd_open(struct inode *inode, struct file *file)
514 {
515 	long minor = iminor(inode);
516 
517 	file->private_data = (void *) minor;
518 	return 0;
519 }
520 
521 static const struct file_operations nvdimm_bus_fops = {
522 	.owner = THIS_MODULE,
523 	.open = nd_open,
524 	.unlocked_ioctl = nd_ioctl,
525 	.compat_ioctl = nd_ioctl,
526 	.llseek = noop_llseek,
527 };
528 
529 static const struct file_operations nvdimm_fops = {
530 	.owner = THIS_MODULE,
531 	.open = nd_open,
532 	.unlocked_ioctl = nvdimm_ioctl,
533 	.compat_ioctl = nvdimm_ioctl,
534 	.llseek = noop_llseek,
535 };
536 
537 int __init nvdimm_bus_init(void)
538 {
539 	int rc;
540 
541 	rc = bus_register(&nvdimm_bus_type);
542 	if (rc)
543 		return rc;
544 
545 	rc = register_chrdev(0, "ndctl", &nvdimm_bus_fops);
546 	if (rc < 0)
547 		goto err_bus_chrdev;
548 	nvdimm_bus_major = rc;
549 
550 	rc = register_chrdev(0, "dimmctl", &nvdimm_fops);
551 	if (rc < 0)
552 		goto err_dimm_chrdev;
553 	nvdimm_major = rc;
554 
555 	nd_class = class_create(THIS_MODULE, "nd");
556 	if (IS_ERR(nd_class))
557 		goto err_class;
558 
559 	return 0;
560 
561  err_class:
562 	unregister_chrdev(nvdimm_major, "dimmctl");
563  err_dimm_chrdev:
564 	unregister_chrdev(nvdimm_bus_major, "ndctl");
565  err_bus_chrdev:
566 	bus_unregister(&nvdimm_bus_type);
567 
568 	return rc;
569 }
570 
571 void nvdimm_bus_exit(void)
572 {
573 	class_destroy(nd_class);
574 	unregister_chrdev(nvdimm_bus_major, "ndctl");
575 	unregister_chrdev(nvdimm_major, "dimmctl");
576 	bus_unregister(&nvdimm_bus_type);
577 }
578