xref: /openbmc/linux/drivers/sbus/char/openprom.c (revision e58e871b)
1 /*
2  * Linux/SPARC PROM Configuration Driver
3  * Copyright (C) 1996 Thomas K. Dyas (tdyas@noc.rutgers.edu)
4  * Copyright (C) 1996 Eddie C. Dost  (ecd@skynet.be)
5  *
6  * This character device driver allows user programs to access the
7  * PROM device tree. It is compatible with the SunOS /dev/openprom
8  * driver and the NetBSD /dev/openprom driver. The SunOS eeprom
9  * utility works without any modifications.
10  *
11  * The driver uses a minor number under the misc device major. The
12  * file read/write mode determines the type of access to the PROM.
13  * Interrupts are disabled whenever the driver calls into the PROM for
14  * sanity's sake.
15  */
16 
17 /* This program is free software; you can redistribute it and/or
18  * modify it under the terms of the GNU General Public License as
19  * published by the Free Software Foundation; either version 2 of the
20  * License, or (at your option) any later version.
21  *
22  * This program is distributed in the hope that it will be useful, but
23  * WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
25  * General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with this program; if not, write to the Free Software
29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
30  */
31 
32 #include <linux/module.h>
33 #include <linux/kernel.h>
34 #include <linux/errno.h>
35 #include <linux/slab.h>
36 #include <linux/mutex.h>
37 #include <linux/string.h>
38 #include <linux/miscdevice.h>
39 #include <linux/init.h>
40 #include <linux/fs.h>
41 #include <asm/oplib.h>
42 #include <asm/prom.h>
43 #include <linux/uaccess.h>
44 #include <asm/openpromio.h>
45 #ifdef CONFIG_PCI
46 #include <linux/pci.h>
47 #endif
48 
49 MODULE_AUTHOR("Thomas K. Dyas (tdyas@noc.rutgers.edu) and Eddie C. Dost  (ecd@skynet.be)");
50 MODULE_DESCRIPTION("OPENPROM Configuration Driver");
51 MODULE_LICENSE("GPL");
52 MODULE_VERSION("1.0");
53 MODULE_ALIAS_MISCDEV(SUN_OPENPROM_MINOR);
54 
55 /* Private data kept by the driver for each descriptor. */
56 typedef struct openprom_private_data
57 {
58 	struct device_node *current_node; /* Current node for SunOS ioctls. */
59 	struct device_node *lastnode; /* Last valid node used by BSD ioctls. */
60 } DATA;
61 
62 /* ID of the PROM node containing all of the EEPROM options. */
63 static DEFINE_MUTEX(openprom_mutex);
64 static struct device_node *options_node;
65 
66 /*
67  * Copy an openpromio structure into kernel space from user space.
68  * This routine does error checking to make sure that all memory
69  * accesses are within bounds. A pointer to the allocated openpromio
70  * structure will be placed in "*opp_p". Return value is the length
71  * of the user supplied buffer.
72  */
73 static int copyin(struct openpromio __user *info, struct openpromio **opp_p)
74 {
75 	unsigned int bufsize;
76 
77 	if (!info || !opp_p)
78 		return -EFAULT;
79 
80 	if (get_user(bufsize, &info->oprom_size))
81 		return -EFAULT;
82 
83 	if (bufsize == 0)
84 		return -EINVAL;
85 
86 	/* If the bufsize is too large, just limit it.
87 	 * Fix from Jason Rappleye.
88 	 */
89 	if (bufsize > OPROMMAXPARAM)
90 		bufsize = OPROMMAXPARAM;
91 
92 	if (!(*opp_p = kzalloc(sizeof(int) + bufsize + 1, GFP_KERNEL)))
93 		return -ENOMEM;
94 
95 	if (copy_from_user(&(*opp_p)->oprom_array,
96 			   &info->oprom_array, bufsize)) {
97 		kfree(*opp_p);
98 		return -EFAULT;
99 	}
100 	return bufsize;
101 }
102 
103 static int getstrings(struct openpromio __user *info, struct openpromio **opp_p)
104 {
105 	int n, bufsize;
106 	char c;
107 
108 	if (!info || !opp_p)
109 		return -EFAULT;
110 
111 	if (!(*opp_p = kzalloc(sizeof(int) + OPROMMAXPARAM + 1, GFP_KERNEL)))
112 		return -ENOMEM;
113 
114 	(*opp_p)->oprom_size = 0;
115 
116 	n = bufsize = 0;
117 	while ((n < 2) && (bufsize < OPROMMAXPARAM)) {
118 		if (get_user(c, &info->oprom_array[bufsize])) {
119 			kfree(*opp_p);
120 			return -EFAULT;
121 		}
122 		if (c == '\0')
123 			n++;
124 		(*opp_p)->oprom_array[bufsize++] = c;
125 	}
126 	if (!n) {
127 		kfree(*opp_p);
128 		return -EINVAL;
129 	}
130 	return bufsize;
131 }
132 
133 /*
134  * Copy an openpromio structure in kernel space back to user space.
135  */
136 static int copyout(void __user *info, struct openpromio *opp, int len)
137 {
138 	if (copy_to_user(info, opp, len))
139 		return -EFAULT;
140 	return 0;
141 }
142 
143 static int opromgetprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)
144 {
145 	const void *pval;
146 	int len;
147 
148 	if (!dp ||
149 	    !(pval = of_get_property(dp, op->oprom_array, &len)) ||
150 	    len <= 0 || len > bufsize)
151 		return copyout(argp, op, sizeof(int));
152 
153 	memcpy(op->oprom_array, pval, len);
154 	op->oprom_array[len] = '\0';
155 	op->oprom_size = len;
156 
157 	return copyout(argp, op, sizeof(int) + bufsize);
158 }
159 
160 static int opromnxtprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)
161 {
162 	struct property *prop;
163 	int len;
164 
165 	if (!dp)
166 		return copyout(argp, op, sizeof(int));
167 	if (op->oprom_array[0] == '\0') {
168 		prop = dp->properties;
169 		if (!prop)
170 			return copyout(argp, op, sizeof(int));
171 		len = strlen(prop->name);
172 	} else {
173 		prop = of_find_property(dp, op->oprom_array, NULL);
174 
175 		if (!prop ||
176 		    !prop->next ||
177 		    (len = strlen(prop->next->name)) + 1 > bufsize)
178 			return copyout(argp, op, sizeof(int));
179 
180 		prop = prop->next;
181 	}
182 
183 	memcpy(op->oprom_array, prop->name, len);
184 	op->oprom_array[len] = '\0';
185 	op->oprom_size = ++len;
186 
187 	return copyout(argp, op, sizeof(int) + bufsize);
188 }
189 
190 static int opromsetopt(struct device_node *dp, struct openpromio *op, int bufsize)
191 {
192 	char *buf = op->oprom_array + strlen(op->oprom_array) + 1;
193 	int len = op->oprom_array + bufsize - buf;
194 
195 	return of_set_property(options_node, op->oprom_array, buf, len);
196 }
197 
198 static int opromnext(void __user *argp, unsigned int cmd, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
199 {
200 	phandle ph;
201 
202 	BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
203 
204 	if (bufsize < sizeof(phandle))
205 		return -EINVAL;
206 
207 	ph = *((int *) op->oprom_array);
208 	if (ph) {
209 		dp = of_find_node_by_phandle(ph);
210 		if (!dp)
211 			return -EINVAL;
212 
213 		switch (cmd) {
214 		case OPROMNEXT:
215 			dp = dp->sibling;
216 			break;
217 
218 		case OPROMCHILD:
219 			dp = dp->child;
220 			break;
221 
222 		case OPROMSETCUR:
223 		default:
224 			break;
225 		}
226 	} else {
227 		/* Sibling of node zero is the root node.  */
228 		if (cmd != OPROMNEXT)
229 			return -EINVAL;
230 
231 		dp = of_find_node_by_path("/");
232 	}
233 
234 	ph = 0;
235 	if (dp)
236 		ph = dp->phandle;
237 
238 	data->current_node = dp;
239 	*((int *) op->oprom_array) = ph;
240 	op->oprom_size = sizeof(phandle);
241 
242 	return copyout(argp, op, bufsize + sizeof(int));
243 }
244 
245 static int oprompci2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
246 {
247 	int err = -EINVAL;
248 
249 	if (bufsize >= 2*sizeof(int)) {
250 #ifdef CONFIG_PCI
251 		struct pci_dev *pdev;
252 		struct device_node *dp;
253 
254 		pdev = pci_get_bus_and_slot (((int *) op->oprom_array)[0],
255 				      ((int *) op->oprom_array)[1]);
256 
257 		dp = pci_device_to_OF_node(pdev);
258 		data->current_node = dp;
259 		*((int *)op->oprom_array) = dp->phandle;
260 		op->oprom_size = sizeof(int);
261 		err = copyout(argp, op, bufsize + sizeof(int));
262 
263 		pci_dev_put(pdev);
264 #endif
265 	}
266 
267 	return err;
268 }
269 
270 static int oprompath2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
271 {
272 	phandle ph = 0;
273 
274 	dp = of_find_node_by_path(op->oprom_array);
275 	if (dp)
276 		ph = dp->phandle;
277 	data->current_node = dp;
278 	*((int *)op->oprom_array) = ph;
279 	op->oprom_size = sizeof(int);
280 
281 	return copyout(argp, op, bufsize + sizeof(int));
282 }
283 
284 static int opromgetbootargs(void __user *argp, struct openpromio *op, int bufsize)
285 {
286 	char *buf = saved_command_line;
287 	int len = strlen(buf);
288 
289 	if (len > bufsize)
290 		return -EINVAL;
291 
292 	strcpy(op->oprom_array, buf);
293 	op->oprom_size = len;
294 
295 	return copyout(argp, op, bufsize + sizeof(int));
296 }
297 
298 /*
299  *	SunOS and Solaris /dev/openprom ioctl calls.
300  */
301 static long openprom_sunos_ioctl(struct file * file,
302 				 unsigned int cmd, unsigned long arg,
303 				 struct device_node *dp)
304 {
305 	DATA *data = file->private_data;
306 	struct openpromio *opp = NULL;
307 	int bufsize, error = 0;
308 	static int cnt;
309 	void __user *argp = (void __user *)arg;
310 
311 	if (cmd == OPROMSETOPT)
312 		bufsize = getstrings(argp, &opp);
313 	else
314 		bufsize = copyin(argp, &opp);
315 
316 	if (bufsize < 0)
317 		return bufsize;
318 
319 	mutex_lock(&openprom_mutex);
320 
321 	switch (cmd) {
322 	case OPROMGETOPT:
323 	case OPROMGETPROP:
324 		error = opromgetprop(argp, dp, opp, bufsize);
325 		break;
326 
327 	case OPROMNXTOPT:
328 	case OPROMNXTPROP:
329 		error = opromnxtprop(argp, dp, opp, bufsize);
330 		break;
331 
332 	case OPROMSETOPT:
333 	case OPROMSETOPT2:
334 		error = opromsetopt(dp, opp, bufsize);
335 		break;
336 
337 	case OPROMNEXT:
338 	case OPROMCHILD:
339 	case OPROMSETCUR:
340 		error = opromnext(argp, cmd, dp, opp, bufsize, data);
341 		break;
342 
343 	case OPROMPCI2NODE:
344 		error = oprompci2node(argp, dp, opp, bufsize, data);
345 		break;
346 
347 	case OPROMPATH2NODE:
348 		error = oprompath2node(argp, dp, opp, bufsize, data);
349 		break;
350 
351 	case OPROMGETBOOTARGS:
352 		error = opromgetbootargs(argp, opp, bufsize);
353 		break;
354 
355 	case OPROMU2P:
356 	case OPROMGETCONS:
357 	case OPROMGETFBNAME:
358 		if (cnt++ < 10)
359 			printk(KERN_INFO "openprom_sunos_ioctl: unimplemented ioctl\n");
360 		error = -EINVAL;
361 		break;
362 	default:
363 		if (cnt++ < 10)
364 			printk(KERN_INFO "openprom_sunos_ioctl: cmd 0x%X, arg 0x%lX\n", cmd, arg);
365 		error = -EINVAL;
366 		break;
367 	}
368 
369 	kfree(opp);
370 	mutex_unlock(&openprom_mutex);
371 
372 	return error;
373 }
374 
375 static struct device_node *get_node(phandle n, DATA *data)
376 {
377 	struct device_node *dp = of_find_node_by_phandle(n);
378 
379 	if (dp)
380 		data->lastnode = dp;
381 
382 	return dp;
383 }
384 
385 /* Copy in a whole string from userspace into kernelspace. */
386 static char * copyin_string(char __user *user, size_t len)
387 {
388 	if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
389 		return ERR_PTR(-EINVAL);
390 
391 	return memdup_user_nul(user, len);
392 }
393 
394 /*
395  *	NetBSD /dev/openprom ioctl calls.
396  */
397 static int opiocget(void __user *argp, DATA *data)
398 {
399 	struct opiocdesc op;
400 	struct device_node *dp;
401 	char *str;
402 	const void *pval;
403 	int err, len;
404 
405 	if (copy_from_user(&op, argp, sizeof(op)))
406 		return -EFAULT;
407 
408 	dp = get_node(op.op_nodeid, data);
409 
410 	str = copyin_string(op.op_name, op.op_namelen);
411 	if (IS_ERR(str))
412 		return PTR_ERR(str);
413 
414 	pval = of_get_property(dp, str, &len);
415 	err = 0;
416 	if (!pval || len > op.op_buflen) {
417 		err = -EINVAL;
418 	} else {
419 		op.op_buflen = len;
420 		if (copy_to_user(argp, &op, sizeof(op)) ||
421 		    copy_to_user(op.op_buf, pval, len))
422 			err = -EFAULT;
423 	}
424 	kfree(str);
425 
426 	return err;
427 }
428 
429 static int opiocnextprop(void __user *argp, DATA *data)
430 {
431 	struct opiocdesc op;
432 	struct device_node *dp;
433 	struct property *prop;
434 	char *str;
435 	int len;
436 
437 	if (copy_from_user(&op, argp, sizeof(op)))
438 		return -EFAULT;
439 
440 	dp = get_node(op.op_nodeid, data);
441 	if (!dp)
442 		return -EINVAL;
443 
444 	str = copyin_string(op.op_name, op.op_namelen);
445 	if (IS_ERR(str))
446 		return PTR_ERR(str);
447 
448 	if (str[0] == '\0') {
449 		prop = dp->properties;
450 	} else {
451 		prop = of_find_property(dp, str, NULL);
452 		if (prop)
453 			prop = prop->next;
454 	}
455 	kfree(str);
456 
457 	if (!prop)
458 		len = 0;
459 	else
460 		len = prop->length;
461 
462 	if (len > op.op_buflen)
463 		len = op.op_buflen;
464 
465 	if (copy_to_user(argp, &op, sizeof(op)))
466 		return -EFAULT;
467 
468 	if (len &&
469 	    copy_to_user(op.op_buf, prop->value, len))
470 		return -EFAULT;
471 
472 	return 0;
473 }
474 
475 static int opiocset(void __user *argp, DATA *data)
476 {
477 	struct opiocdesc op;
478 	struct device_node *dp;
479 	char *str, *tmp;
480 	int err;
481 
482 	if (copy_from_user(&op, argp, sizeof(op)))
483 		return -EFAULT;
484 
485 	dp = get_node(op.op_nodeid, data);
486 	if (!dp)
487 		return -EINVAL;
488 
489 	str = copyin_string(op.op_name, op.op_namelen);
490 	if (IS_ERR(str))
491 		return PTR_ERR(str);
492 
493 	tmp = copyin_string(op.op_buf, op.op_buflen);
494 	if (IS_ERR(tmp)) {
495 		kfree(str);
496 		return PTR_ERR(tmp);
497 	}
498 
499 	err = of_set_property(dp, str, tmp, op.op_buflen);
500 
501 	kfree(str);
502 	kfree(tmp);
503 
504 	return err;
505 }
506 
507 static int opiocgetnext(unsigned int cmd, void __user *argp)
508 {
509 	struct device_node *dp;
510 	phandle nd;
511 
512 	BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
513 
514 	if (copy_from_user(&nd, argp, sizeof(phandle)))
515 		return -EFAULT;
516 
517 	if (nd == 0) {
518 		if (cmd != OPIOCGETNEXT)
519 			return -EINVAL;
520 		dp = of_find_node_by_path("/");
521 	} else {
522 		dp = of_find_node_by_phandle(nd);
523 		nd = 0;
524 		if (dp) {
525 			if (cmd == OPIOCGETNEXT)
526 				dp = dp->sibling;
527 			else
528 				dp = dp->child;
529 		}
530 	}
531 	if (dp)
532 		nd = dp->phandle;
533 	if (copy_to_user(argp, &nd, sizeof(phandle)))
534 		return -EFAULT;
535 
536 	return 0;
537 }
538 
539 static int openprom_bsd_ioctl(struct file * file,
540 			      unsigned int cmd, unsigned long arg)
541 {
542 	DATA *data = file->private_data;
543 	void __user *argp = (void __user *)arg;
544 	int err;
545 
546 	mutex_lock(&openprom_mutex);
547 	switch (cmd) {
548 	case OPIOCGET:
549 		err = opiocget(argp, data);
550 		break;
551 
552 	case OPIOCNEXTPROP:
553 		err = opiocnextprop(argp, data);
554 		break;
555 
556 	case OPIOCSET:
557 		err = opiocset(argp, data);
558 		break;
559 
560 	case OPIOCGETOPTNODE:
561 		BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
562 
563 		err = 0;
564 		if (copy_to_user(argp, &options_node->phandle, sizeof(phandle)))
565 			err = -EFAULT;
566 		break;
567 
568 	case OPIOCGETNEXT:
569 	case OPIOCGETCHILD:
570 		err = opiocgetnext(cmd, argp);
571 		break;
572 
573 	default:
574 		err = -EINVAL;
575 		break;
576 	}
577 	mutex_unlock(&openprom_mutex);
578 
579 	return err;
580 }
581 
582 
583 /*
584  *	Handoff control to the correct ioctl handler.
585  */
586 static long openprom_ioctl(struct file * file,
587 			   unsigned int cmd, unsigned long arg)
588 {
589 	DATA *data = file->private_data;
590 
591 	switch (cmd) {
592 	case OPROMGETOPT:
593 	case OPROMNXTOPT:
594 		if ((file->f_mode & FMODE_READ) == 0)
595 			return -EPERM;
596 		return openprom_sunos_ioctl(file, cmd, arg,
597 					    options_node);
598 
599 	case OPROMSETOPT:
600 	case OPROMSETOPT2:
601 		if ((file->f_mode & FMODE_WRITE) == 0)
602 			return -EPERM;
603 		return openprom_sunos_ioctl(file, cmd, arg,
604 					    options_node);
605 
606 	case OPROMNEXT:
607 	case OPROMCHILD:
608 	case OPROMGETPROP:
609 	case OPROMNXTPROP:
610 		if ((file->f_mode & FMODE_READ) == 0)
611 			return -EPERM;
612 		return openprom_sunos_ioctl(file, cmd, arg,
613 					    data->current_node);
614 
615 	case OPROMU2P:
616 	case OPROMGETCONS:
617 	case OPROMGETFBNAME:
618 	case OPROMGETBOOTARGS:
619 	case OPROMSETCUR:
620 	case OPROMPCI2NODE:
621 	case OPROMPATH2NODE:
622 		if ((file->f_mode & FMODE_READ) == 0)
623 			return -EPERM;
624 		return openprom_sunos_ioctl(file, cmd, arg, NULL);
625 
626 	case OPIOCGET:
627 	case OPIOCNEXTPROP:
628 	case OPIOCGETOPTNODE:
629 	case OPIOCGETNEXT:
630 	case OPIOCGETCHILD:
631 		if ((file->f_mode & FMODE_READ) == 0)
632 			return -EBADF;
633 		return openprom_bsd_ioctl(file,cmd,arg);
634 
635 	case OPIOCSET:
636 		if ((file->f_mode & FMODE_WRITE) == 0)
637 			return -EBADF;
638 		return openprom_bsd_ioctl(file,cmd,arg);
639 
640 	default:
641 		return -EINVAL;
642 	};
643 }
644 
645 static long openprom_compat_ioctl(struct file *file, unsigned int cmd,
646 		unsigned long arg)
647 {
648 	long rval = -ENOTTY;
649 
650 	/*
651 	 * SunOS/Solaris only, the NetBSD one's have embedded pointers in
652 	 * the arg which we'd need to clean up...
653 	 */
654 	switch (cmd) {
655 	case OPROMGETOPT:
656 	case OPROMSETOPT:
657 	case OPROMNXTOPT:
658 	case OPROMSETOPT2:
659 	case OPROMNEXT:
660 	case OPROMCHILD:
661 	case OPROMGETPROP:
662 	case OPROMNXTPROP:
663 	case OPROMU2P:
664 	case OPROMGETCONS:
665 	case OPROMGETFBNAME:
666 	case OPROMGETBOOTARGS:
667 	case OPROMSETCUR:
668 	case OPROMPCI2NODE:
669 	case OPROMPATH2NODE:
670 		rval = openprom_ioctl(file, cmd, arg);
671 		break;
672 	}
673 
674 	return rval;
675 }
676 
677 static int openprom_open(struct inode * inode, struct file * file)
678 {
679 	DATA *data;
680 
681 	data = kmalloc(sizeof(DATA), GFP_KERNEL);
682 	if (!data)
683 		return -ENOMEM;
684 
685 	mutex_lock(&openprom_mutex);
686 	data->current_node = of_find_node_by_path("/");
687 	data->lastnode = data->current_node;
688 	file->private_data = (void *) data;
689 	mutex_unlock(&openprom_mutex);
690 
691 	return 0;
692 }
693 
694 static int openprom_release(struct inode * inode, struct file * file)
695 {
696 	kfree(file->private_data);
697 	return 0;
698 }
699 
700 static const struct file_operations openprom_fops = {
701 	.owner =	THIS_MODULE,
702 	.llseek =	no_llseek,
703 	.unlocked_ioctl = openprom_ioctl,
704 	.compat_ioctl =	openprom_compat_ioctl,
705 	.open =		openprom_open,
706 	.release =	openprom_release,
707 };
708 
709 static struct miscdevice openprom_dev = {
710 	.minor		= SUN_OPENPROM_MINOR,
711 	.name		= "openprom",
712 	.fops		= &openprom_fops,
713 };
714 
715 static int __init openprom_init(void)
716 {
717 	struct device_node *dp;
718 	int err;
719 
720 	err = misc_register(&openprom_dev);
721 	if (err)
722 		return err;
723 
724 	dp = of_find_node_by_path("/");
725 	dp = dp->child;
726 	while (dp) {
727 		if (!strcmp(dp->name, "options"))
728 			break;
729 		dp = dp->sibling;
730 	}
731 	options_node = dp;
732 
733 	if (!options_node) {
734 		misc_deregister(&openprom_dev);
735 		return -EIO;
736 	}
737 
738 	return 0;
739 }
740 
741 static void __exit openprom_cleanup(void)
742 {
743 	misc_deregister(&openprom_dev);
744 }
745 
746 module_init(openprom_init);
747 module_exit(openprom_cleanup);
748