xref: /openbmc/linux/drivers/sbus/char/openprom.c (revision 22246614)
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/string.h>
37 #include <linux/miscdevice.h>
38 #include <linux/init.h>
39 #include <linux/fs.h>
40 #include <asm/oplib.h>
41 #include <asm/prom.h>
42 #include <asm/system.h>
43 #include <asm/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 
54 /* Private data kept by the driver for each descriptor. */
55 typedef struct openprom_private_data
56 {
57 	struct device_node *current_node; /* Current node for SunOS ioctls. */
58 	struct device_node *lastnode; /* Last valid node used by BSD ioctls. */
59 } DATA;
60 
61 /* ID of the PROM node containing all of the EEPROM options. */
62 static struct device_node *options_node;
63 
64 /*
65  * Copy an openpromio structure into kernel space from user space.
66  * This routine does error checking to make sure that all memory
67  * accesses are within bounds. A pointer to the allocated openpromio
68  * structure will be placed in "*opp_p". Return value is the length
69  * of the user supplied buffer.
70  */
71 static int copyin(struct openpromio __user *info, struct openpromio **opp_p)
72 {
73 	unsigned int bufsize;
74 
75 	if (!info || !opp_p)
76 		return -EFAULT;
77 
78 	if (get_user(bufsize, &info->oprom_size))
79 		return -EFAULT;
80 
81 	if (bufsize == 0)
82 		return -EINVAL;
83 
84 	/* If the bufsize is too large, just limit it.
85 	 * Fix from Jason Rappleye.
86 	 */
87 	if (bufsize > OPROMMAXPARAM)
88 		bufsize = OPROMMAXPARAM;
89 
90 	if (!(*opp_p = kzalloc(sizeof(int) + bufsize + 1, GFP_KERNEL)))
91 		return -ENOMEM;
92 
93 	if (copy_from_user(&(*opp_p)->oprom_array,
94 			   &info->oprom_array, bufsize)) {
95 		kfree(*opp_p);
96 		return -EFAULT;
97 	}
98 	return bufsize;
99 }
100 
101 static int getstrings(struct openpromio __user *info, struct openpromio **opp_p)
102 {
103 	int n, bufsize;
104 	char c;
105 
106 	if (!info || !opp_p)
107 		return -EFAULT;
108 
109 	if (!(*opp_p = kzalloc(sizeof(int) + OPROMMAXPARAM + 1, GFP_KERNEL)))
110 		return -ENOMEM;
111 
112 	(*opp_p)->oprom_size = 0;
113 
114 	n = bufsize = 0;
115 	while ((n < 2) && (bufsize < OPROMMAXPARAM)) {
116 		if (get_user(c, &info->oprom_array[bufsize])) {
117 			kfree(*opp_p);
118 			return -EFAULT;
119 		}
120 		if (c == '\0')
121 			n++;
122 		(*opp_p)->oprom_array[bufsize++] = c;
123 	}
124 	if (!n) {
125 		kfree(*opp_p);
126 		return -EINVAL;
127 	}
128 	return bufsize;
129 }
130 
131 /*
132  * Copy an openpromio structure in kernel space back to user space.
133  */
134 static int copyout(void __user *info, struct openpromio *opp, int len)
135 {
136 	if (copy_to_user(info, opp, len))
137 		return -EFAULT;
138 	return 0;
139 }
140 
141 static int opromgetprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)
142 {
143 	const void *pval;
144 	int len;
145 
146 	if (!dp ||
147 	    !(pval = of_get_property(dp, op->oprom_array, &len)) ||
148 	    len <= 0 || len > bufsize)
149 		return copyout(argp, op, sizeof(int));
150 
151 	memcpy(op->oprom_array, pval, len);
152 	op->oprom_array[len] = '\0';
153 	op->oprom_size = len;
154 
155 	return copyout(argp, op, sizeof(int) + bufsize);
156 }
157 
158 static int opromnxtprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)
159 {
160 	struct property *prop;
161 	int len;
162 
163 	if (!dp)
164 		return copyout(argp, op, sizeof(int));
165 	if (op->oprom_array[0] == '\0') {
166 		prop = dp->properties;
167 		if (!prop)
168 			return copyout(argp, op, sizeof(int));
169 		len = strlen(prop->name);
170 	} else {
171 		prop = of_find_property(dp, op->oprom_array, NULL);
172 
173 		if (!prop ||
174 		    !prop->next ||
175 		    (len = strlen(prop->next->name)) + 1 > bufsize)
176 			return copyout(argp, op, sizeof(int));
177 
178 		prop = prop->next;
179 	}
180 
181 	memcpy(op->oprom_array, prop->name, len);
182 	op->oprom_array[len] = '\0';
183 	op->oprom_size = ++len;
184 
185 	return copyout(argp, op, sizeof(int) + bufsize);
186 }
187 
188 static int opromsetopt(struct device_node *dp, struct openpromio *op, int bufsize)
189 {
190 	char *buf = op->oprom_array + strlen(op->oprom_array) + 1;
191 	int len = op->oprom_array + bufsize - buf;
192 
193 	return of_set_property(options_node, op->oprom_array, buf, len);
194 }
195 
196 static int opromnext(void __user *argp, unsigned int cmd, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
197 {
198 	phandle ph;
199 
200 	BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
201 
202 	if (bufsize < sizeof(phandle))
203 		return -EINVAL;
204 
205 	ph = *((int *) op->oprom_array);
206 	if (ph) {
207 		dp = of_find_node_by_phandle(ph);
208 		if (!dp)
209 			return -EINVAL;
210 
211 		switch (cmd) {
212 		case OPROMNEXT:
213 			dp = dp->sibling;
214 			break;
215 
216 		case OPROMCHILD:
217 			dp = dp->child;
218 			break;
219 
220 		case OPROMSETCUR:
221 		default:
222 			break;
223 		};
224 	} else {
225 		/* Sibling of node zero is the root node.  */
226 		if (cmd != OPROMNEXT)
227 			return -EINVAL;
228 
229 		dp = of_find_node_by_path("/");
230 	}
231 
232 	ph = 0;
233 	if (dp)
234 		ph = dp->node;
235 
236 	data->current_node = dp;
237 	*((int *) op->oprom_array) = ph;
238 	op->oprom_size = sizeof(phandle);
239 
240 	return copyout(argp, op, bufsize + sizeof(int));
241 }
242 
243 static int oprompci2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
244 {
245 	int err = -EINVAL;
246 
247 	if (bufsize >= 2*sizeof(int)) {
248 #ifdef CONFIG_PCI
249 		struct pci_dev *pdev;
250 		struct device_node *dp;
251 
252 		pdev = pci_get_bus_and_slot (((int *) op->oprom_array)[0],
253 				      ((int *) op->oprom_array)[1]);
254 
255 		dp = pci_device_to_OF_node(pdev);
256 		data->current_node = dp;
257 		*((int *)op->oprom_array) = dp->node;
258 		op->oprom_size = sizeof(int);
259 		err = copyout(argp, op, bufsize + sizeof(int));
260 
261 		pci_dev_put(pdev);
262 #endif
263 	}
264 
265 	return err;
266 }
267 
268 static int oprompath2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)
269 {
270 	phandle ph = 0;
271 
272 	dp = of_find_node_by_path(op->oprom_array);
273 	if (dp)
274 		ph = dp->node;
275 	data->current_node = dp;
276 	*((int *)op->oprom_array) = ph;
277 	op->oprom_size = sizeof(int);
278 
279 	return copyout(argp, op, bufsize + sizeof(int));
280 }
281 
282 static int opromgetbootargs(void __user *argp, struct openpromio *op, int bufsize)
283 {
284 	char *buf = saved_command_line;
285 	int len = strlen(buf);
286 
287 	if (len > bufsize)
288 		return -EINVAL;
289 
290 	strcpy(op->oprom_array, buf);
291 	op->oprom_size = len;
292 
293 	return copyout(argp, op, bufsize + sizeof(int));
294 }
295 
296 /*
297  *	SunOS and Solaris /dev/openprom ioctl calls.
298  */
299 static int openprom_sunos_ioctl(struct inode * inode, struct file * file,
300 				unsigned int cmd, unsigned long arg,
301 				struct device_node *dp)
302 {
303 	DATA *data = file->private_data;
304 	struct openpromio *opp;
305 	int bufsize, error = 0;
306 	static int cnt;
307 	void __user *argp = (void __user *)arg;
308 
309 	if (cmd == OPROMSETOPT)
310 		bufsize = getstrings(argp, &opp);
311 	else
312 		bufsize = copyin(argp, &opp);
313 
314 	if (bufsize < 0)
315 		return bufsize;
316 
317 	switch (cmd) {
318 	case OPROMGETOPT:
319 	case OPROMGETPROP:
320 		error = opromgetprop(argp, dp, opp, bufsize);
321 		break;
322 
323 	case OPROMNXTOPT:
324 	case OPROMNXTPROP:
325 		error = opromnxtprop(argp, dp, opp, bufsize);
326 		break;
327 
328 	case OPROMSETOPT:
329 	case OPROMSETOPT2:
330 		error = opromsetopt(dp, opp, bufsize);
331 		break;
332 
333 	case OPROMNEXT:
334 	case OPROMCHILD:
335 	case OPROMSETCUR:
336 		error = opromnext(argp, cmd, dp, opp, bufsize, data);
337 		break;
338 
339 	case OPROMPCI2NODE:
340 		error = oprompci2node(argp, dp, opp, bufsize, data);
341 		break;
342 
343 	case OPROMPATH2NODE:
344 		error = oprompath2node(argp, dp, opp, bufsize, data);
345 		break;
346 
347 	case OPROMGETBOOTARGS:
348 		error = opromgetbootargs(argp, opp, bufsize);
349 		break;
350 
351 	case OPROMU2P:
352 	case OPROMGETCONS:
353 	case OPROMGETFBNAME:
354 		if (cnt++ < 10)
355 			printk(KERN_INFO "openprom_sunos_ioctl: unimplemented ioctl\n");
356 		error = -EINVAL;
357 		break;
358 	default:
359 		if (cnt++ < 10)
360 			printk(KERN_INFO "openprom_sunos_ioctl: cmd 0x%X, arg 0x%lX\n", cmd, arg);
361 		error = -EINVAL;
362 		break;
363 	}
364 
365 	kfree(opp);
366 	return error;
367 }
368 
369 static struct device_node *get_node(phandle n, DATA *data)
370 {
371 	struct device_node *dp = of_find_node_by_phandle(n);
372 
373 	if (dp)
374 		data->lastnode = dp;
375 
376 	return dp;
377 }
378 
379 /* Copy in a whole string from userspace into kernelspace. */
380 static int copyin_string(char __user *user, size_t len, char **ptr)
381 {
382 	char *tmp;
383 
384 	if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
385 		return -EINVAL;
386 
387 	tmp = kmalloc(len + 1, GFP_KERNEL);
388 	if (!tmp)
389 		return -ENOMEM;
390 
391 	if (copy_from_user(tmp, user, len)) {
392 		kfree(tmp);
393 		return -EFAULT;
394 	}
395 
396 	tmp[len] = '\0';
397 
398 	*ptr = tmp;
399 
400 	return 0;
401 }
402 
403 /*
404  *	NetBSD /dev/openprom ioctl calls.
405  */
406 static int opiocget(void __user *argp, DATA *data)
407 {
408 	struct opiocdesc op;
409 	struct device_node *dp;
410 	char *str;
411 	const void *pval;
412 	int err, len;
413 
414 	if (copy_from_user(&op, argp, sizeof(op)))
415 		return -EFAULT;
416 
417 	dp = get_node(op.op_nodeid, data);
418 
419 	err = copyin_string(op.op_name, op.op_namelen, &str);
420 	if (err)
421 		return err;
422 
423 	pval = of_get_property(dp, str, &len);
424 	err = 0;
425 	if (!pval || len > op.op_buflen) {
426 		err = -EINVAL;
427 	} else {
428 		op.op_buflen = len;
429 		if (copy_to_user(argp, &op, sizeof(op)) ||
430 		    copy_to_user(op.op_buf, pval, len))
431 			err = -EFAULT;
432 	}
433 	kfree(str);
434 
435 	return err;
436 }
437 
438 static int opiocnextprop(void __user *argp, DATA *data)
439 {
440 	struct opiocdesc op;
441 	struct device_node *dp;
442 	struct property *prop;
443 	char *str;
444 	int err, len;
445 
446 	if (copy_from_user(&op, argp, sizeof(op)))
447 		return -EFAULT;
448 
449 	dp = get_node(op.op_nodeid, data);
450 	if (!dp)
451 		return -EINVAL;
452 
453 	err = copyin_string(op.op_name, op.op_namelen, &str);
454 	if (err)
455 		return err;
456 
457 	if (str[0] == '\0') {
458 		prop = dp->properties;
459 	} else {
460 		prop = of_find_property(dp, str, NULL);
461 		if (prop)
462 			prop = prop->next;
463 	}
464 	kfree(str);
465 
466 	if (!prop)
467 		len = 0;
468 	else
469 		len = prop->length;
470 
471 	if (len > op.op_buflen)
472 		len = op.op_buflen;
473 
474 	if (copy_to_user(argp, &op, sizeof(op)))
475 		return -EFAULT;
476 
477 	if (len &&
478 	    copy_to_user(op.op_buf, prop->value, len))
479 		return -EFAULT;
480 
481 	return 0;
482 }
483 
484 static int opiocset(void __user *argp, DATA *data)
485 {
486 	struct opiocdesc op;
487 	struct device_node *dp;
488 	char *str, *tmp;
489 	int err;
490 
491 	if (copy_from_user(&op, argp, sizeof(op)))
492 		return -EFAULT;
493 
494 	dp = get_node(op.op_nodeid, data);
495 	if (!dp)
496 		return -EINVAL;
497 
498 	err = copyin_string(op.op_name, op.op_namelen, &str);
499 	if (err)
500 		return err;
501 
502 	err = copyin_string(op.op_buf, op.op_buflen, &tmp);
503 	if (err) {
504 		kfree(str);
505 		return err;
506 	}
507 
508 	err = of_set_property(dp, str, tmp, op.op_buflen);
509 
510 	kfree(str);
511 	kfree(tmp);
512 
513 	return err;
514 }
515 
516 static int opiocgetnext(unsigned int cmd, void __user *argp)
517 {
518 	struct device_node *dp;
519 	phandle nd;
520 
521 	BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
522 
523 	if (copy_from_user(&nd, argp, sizeof(phandle)))
524 		return -EFAULT;
525 
526 	if (nd == 0) {
527 		if (cmd != OPIOCGETNEXT)
528 			return -EINVAL;
529 		dp = of_find_node_by_path("/");
530 	} else {
531 		dp = of_find_node_by_phandle(nd);
532 		nd = 0;
533 		if (dp) {
534 			if (cmd == OPIOCGETNEXT)
535 				dp = dp->sibling;
536 			else
537 				dp = dp->child;
538 		}
539 	}
540 	if (dp)
541 		nd = dp->node;
542 	if (copy_to_user(argp, &nd, sizeof(phandle)))
543 		return -EFAULT;
544 
545 	return 0;
546 }
547 
548 static int openprom_bsd_ioctl(struct inode * inode, struct file * file,
549 			      unsigned int cmd, unsigned long arg)
550 {
551 	DATA *data = (DATA *) file->private_data;
552 	void __user *argp = (void __user *)arg;
553 	int err;
554 
555 	switch (cmd) {
556 	case OPIOCGET:
557 		err = opiocget(argp, data);
558 		break;
559 
560 	case OPIOCNEXTPROP:
561 		err = opiocnextprop(argp, data);
562 		break;
563 
564 	case OPIOCSET:
565 		err = opiocset(argp, data);
566 		break;
567 
568 	case OPIOCGETOPTNODE:
569 		BUILD_BUG_ON(sizeof(phandle) != sizeof(int));
570 
571 		if (copy_to_user(argp, &options_node->node, sizeof(phandle)))
572 			return -EFAULT;
573 
574 		return 0;
575 
576 	case OPIOCGETNEXT:
577 	case OPIOCGETCHILD:
578 		err = opiocgetnext(cmd, argp);
579 		break;
580 
581 	default:
582 		return -EINVAL;
583 
584 	};
585 
586 	return err;
587 }
588 
589 
590 /*
591  *	Handoff control to the correct ioctl handler.
592  */
593 static int openprom_ioctl(struct inode * inode, struct file * file,
594 			  unsigned int cmd, unsigned long arg)
595 {
596 	DATA *data = (DATA *) file->private_data;
597 
598 	switch (cmd) {
599 	case OPROMGETOPT:
600 	case OPROMNXTOPT:
601 		if ((file->f_mode & FMODE_READ) == 0)
602 			return -EPERM;
603 		return openprom_sunos_ioctl(inode, file, cmd, arg,
604 					    options_node);
605 
606 	case OPROMSETOPT:
607 	case OPROMSETOPT2:
608 		if ((file->f_mode & FMODE_WRITE) == 0)
609 			return -EPERM;
610 		return openprom_sunos_ioctl(inode, file, cmd, arg,
611 					    options_node);
612 
613 	case OPROMNEXT:
614 	case OPROMCHILD:
615 	case OPROMGETPROP:
616 	case OPROMNXTPROP:
617 		if ((file->f_mode & FMODE_READ) == 0)
618 			return -EPERM;
619 		return openprom_sunos_ioctl(inode, file, cmd, arg,
620 					    data->current_node);
621 
622 	case OPROMU2P:
623 	case OPROMGETCONS:
624 	case OPROMGETFBNAME:
625 	case OPROMGETBOOTARGS:
626 	case OPROMSETCUR:
627 	case OPROMPCI2NODE:
628 	case OPROMPATH2NODE:
629 		if ((file->f_mode & FMODE_READ) == 0)
630 			return -EPERM;
631 		return openprom_sunos_ioctl(inode, file, cmd, arg, NULL);
632 
633 	case OPIOCGET:
634 	case OPIOCNEXTPROP:
635 	case OPIOCGETOPTNODE:
636 	case OPIOCGETNEXT:
637 	case OPIOCGETCHILD:
638 		if ((file->f_mode & FMODE_READ) == 0)
639 			return -EBADF;
640 		return openprom_bsd_ioctl(inode,file,cmd,arg);
641 
642 	case OPIOCSET:
643 		if ((file->f_mode & FMODE_WRITE) == 0)
644 			return -EBADF;
645 		return openprom_bsd_ioctl(inode,file,cmd,arg);
646 
647 	default:
648 		return -EINVAL;
649 	};
650 }
651 
652 static long openprom_compat_ioctl(struct file *file, unsigned int cmd,
653 		unsigned long arg)
654 {
655 	long rval = -ENOTTY;
656 
657 	/*
658 	 * SunOS/Solaris only, the NetBSD one's have embedded pointers in
659 	 * the arg which we'd need to clean up...
660 	 */
661 	switch (cmd) {
662 	case OPROMGETOPT:
663 	case OPROMSETOPT:
664 	case OPROMNXTOPT:
665 	case OPROMSETOPT2:
666 	case OPROMNEXT:
667 	case OPROMCHILD:
668 	case OPROMGETPROP:
669 	case OPROMNXTPROP:
670 	case OPROMU2P:
671 	case OPROMGETCONS:
672 	case OPROMGETFBNAME:
673 	case OPROMGETBOOTARGS:
674 	case OPROMSETCUR:
675 	case OPROMPCI2NODE:
676 	case OPROMPATH2NODE:
677 		rval = openprom_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
678 		break;
679 	}
680 
681 	return rval;
682 }
683 
684 static int openprom_open(struct inode * inode, struct file * file)
685 {
686 	DATA *data;
687 
688 	data = kmalloc(sizeof(DATA), GFP_KERNEL);
689 	if (!data)
690 		return -ENOMEM;
691 
692 	data->current_node = of_find_node_by_path("/");
693 	data->lastnode = data->current_node;
694 	file->private_data = (void *) data;
695 
696 	return 0;
697 }
698 
699 static int openprom_release(struct inode * inode, struct file * file)
700 {
701 	kfree(file->private_data);
702 	return 0;
703 }
704 
705 static const struct file_operations openprom_fops = {
706 	.owner =	THIS_MODULE,
707 	.llseek =	no_llseek,
708 	.ioctl =	openprom_ioctl,
709 	.compat_ioctl =	openprom_compat_ioctl,
710 	.open =		openprom_open,
711 	.release =	openprom_release,
712 };
713 
714 static struct miscdevice openprom_dev = {
715 	.minor		= SUN_OPENPROM_MINOR,
716 	.name		= "openprom",
717 	.fops		= &openprom_fops,
718 };
719 
720 static int __init openprom_init(void)
721 {
722 	struct device_node *dp;
723 	int err;
724 
725 	err = misc_register(&openprom_dev);
726 	if (err)
727 		return err;
728 
729 	dp = of_find_node_by_path("/");
730 	dp = dp->child;
731 	while (dp) {
732 		if (!strcmp(dp->name, "options"))
733 			break;
734 		dp = dp->sibling;
735 	}
736 	options_node = dp;
737 
738 	if (!options_node) {
739 		misc_deregister(&openprom_dev);
740 		return -EIO;
741 	}
742 
743 	return 0;
744 }
745 
746 static void __exit openprom_cleanup(void)
747 {
748 	misc_deregister(&openprom_dev);
749 }
750 
751 module_init(openprom_init);
752 module_exit(openprom_cleanup);
753