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#define PROMLIB_INTERNAL
33
34#include <linux/config.h>
35#include <linux/module.h>
36#include <linux/kernel.h>
37#include <linux/sched.h>
38#include <linux/errno.h>
39#include <linux/slab.h>
40#include <linux/string.h>
41#include <linux/miscdevice.h>
42#include <linux/init.h>
43#include <asm/oplib.h>
44#include <asm/system.h>
45#include <asm/uaccess.h>
46#include <asm/openpromio.h>
47#ifdef CONFIG_PCI
48#include <linux/pci.h>
49#include <asm/pbm.h>
50#endif
51
52/* Private data kept by the driver for each descriptor. */
53typedef struct openprom_private_data
54{
55	int current_node;	/* Current node for SunOS ioctls. */
56	int lastnode;		/* Last valid node used by BSD ioctls. */
57} DATA;
58
59/* ID of the PROM node containing all of the EEPROM options. */
60static int options_node = 0;
61
62/*
63 * Copy an openpromio structure into kernel space from user space.
64 * This routine does error checking to make sure that all memory
65 * accesses are within bounds. A pointer to the allocated openpromio
66 * structure will be placed in "*opp_p". Return value is the length
67 * of the user supplied buffer.
68 */
69static int copyin(struct openpromio *info, struct openpromio **opp_p)
70{
71	int bufsize;
72
73	if (!info || !opp_p)
74		return -EFAULT;
75
76	if (get_user(bufsize, &info->oprom_size))
77		return -EFAULT;
78
79	if (bufsize == 0)
80		return -EINVAL;
81
82	/* If the bufsize is too large, just limit it.
83	 * Fix from Jason Rappleye.
84	 */
85	if (bufsize > OPROMMAXPARAM)
86		bufsize = OPROMMAXPARAM;
87
88	if (!(*opp_p = kmalloc(sizeof(int) + bufsize + 1, GFP_KERNEL)))
89		return -ENOMEM;
90	memset(*opp_p, 0, sizeof(int) + bufsize + 1);
91
92	if (copy_from_user(&(*opp_p)->oprom_array,
93			   &info->oprom_array, bufsize)) {
94		kfree(*opp_p);
95		return -EFAULT;
96	}
97	return bufsize;
98}
99
100static int getstrings(struct openpromio *info, struct openpromio **opp_p)
101{
102	int n, bufsize;
103	char c;
104
105	if (!info || !opp_p)
106		return -EFAULT;
107
108	if (!(*opp_p = kmalloc(sizeof(int) + OPROMMAXPARAM + 1, GFP_KERNEL)))
109		return -ENOMEM;
110
111	memset(*opp_p, 0, sizeof(int) + OPROMMAXPARAM + 1);
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 */
134static int copyout(void *info, struct openpromio *opp, int len)
135{
136	if (copy_to_user(info, opp, len))
137		return -EFAULT;
138	return 0;
139}
140
141/*
142 *	SunOS and Solaris /dev/openprom ioctl calls.
143 */
144static int openprom_sunos_ioctl(struct inode * inode, struct file * file,
145				unsigned int cmd, unsigned long arg, int node)
146{
147	DATA *data = (DATA *) file->private_data;
148	char buffer[OPROMMAXPARAM+1], *buf;
149	struct openpromio *opp;
150	unsigned long flags;
151	int bufsize, len, error = 0;
152	extern char saved_command_line[];
153	static int cnt;
154
155	if (cmd == OPROMSETOPT)
156		bufsize = getstrings((void *)arg, &opp);
157	else
158		bufsize = copyin((void *)arg, &opp);
159
160	if (bufsize < 0)
161		return bufsize;
162
163	switch (cmd) {
164	case OPROMGETOPT:
165	case OPROMGETPROP:
166		save_and_cli(flags);
167		len = prom_getproplen(node, opp->oprom_array);
168		restore_flags(flags);
169
170		if (len <= 0 || len > bufsize) {
171			error = copyout((void *)arg, opp, sizeof(int));
172			break;
173		}
174
175		save_and_cli(flags);
176		len = prom_getproperty(node, opp->oprom_array, buffer, bufsize);
177		restore_flags(flags);
178
179		memcpy(opp->oprom_array, buffer, len);
180		opp->oprom_array[len] = '\0';
181		opp->oprom_size = len;
182
183		error = copyout((void *)arg, opp, sizeof(int) + bufsize);
184		break;
185
186	case OPROMNXTOPT:
187	case OPROMNXTPROP:
188		save_and_cli(flags);
189		buf = prom_nextprop(node, opp->oprom_array, buffer);
190		restore_flags(flags);
191
192		len = strlen(buf);
193		if (len == 0 || len + 1 > bufsize) {
194			error = copyout((void *)arg, opp, sizeof(int));
195			break;
196		}
197
198		memcpy(opp->oprom_array, buf, len);
199		opp->oprom_array[len] = '\0';
200		opp->oprom_size = ++len;
201
202		error = copyout((void *)arg, opp, sizeof(int) + bufsize);
203		break;
204
205	case OPROMSETOPT:
206	case OPROMSETOPT2:
207		buf = opp->oprom_array + strlen(opp->oprom_array) + 1;
208		len = opp->oprom_array + bufsize - buf;
209
210		save_and_cli(flags);
211		error = prom_setprop(options_node, opp->oprom_array,
212				     buf, len);
213		restore_flags(flags);
214
215		if (error < 0)
216			error = -EINVAL;
217		break;
218
219	case OPROMNEXT:
220	case OPROMCHILD:
221	case OPROMSETCUR:
222		if (bufsize < sizeof(int)) {
223			error = -EINVAL;
224			break;
225		}
226
227		node = *((int *) opp->oprom_array);
228
229		save_and_cli(flags);
230		switch (cmd) {
231		case OPROMNEXT: node = __prom_getsibling(node); break;
232		case OPROMCHILD: node = __prom_getchild(node); break;
233		case OPROMSETCUR: break;
234		}
235		restore_flags(flags);
236
237		data->current_node = node;
238		*((int *)opp->oprom_array) = node;
239		opp->oprom_size = sizeof(int);
240
241		error = copyout((void *)arg, opp, bufsize + sizeof(int));
242		break;
243
244	case OPROMPCI2NODE:
245		error = -EINVAL;
246
247		if (bufsize >= 2*sizeof(int)) {
248#ifdef CONFIG_PCI
249			struct pci_dev *pdev;
250			struct pcidev_cookie *pcp;
251			pdev = pci_find_slot (((int *) opp->oprom_array)[0],
252					      ((int *) opp->oprom_array)[1]);
253
254			pcp = pdev->sysdata;
255			if (pcp != NULL && pcp->prom_node != -1 && pcp->prom_node) {
256				node = pcp->prom_node;
257				data->current_node = node;
258				*((int *)opp->oprom_array) = node;
259				opp->oprom_size = sizeof(int);
260				error = copyout((void *)arg, opp, bufsize + sizeof(int));
261			}
262#endif
263		}
264		break;
265
266	case OPROMPATH2NODE:
267		save_and_cli(flags);
268		node = prom_finddevice(opp->oprom_array);
269		restore_flags(flags);
270		data->current_node = node;
271		*((int *)opp->oprom_array) = node;
272		opp->oprom_size = sizeof(int);
273
274		error = copyout((void *)arg, opp, bufsize + sizeof(int));
275		break;
276
277	case OPROMGETBOOTARGS:
278		buf = saved_command_line;
279
280		len = strlen(buf);
281
282		if (len > bufsize) {
283			error = -EINVAL;
284			break;
285		}
286
287		strcpy(opp->oprom_array, buf);
288		opp->oprom_size = len;
289
290		error = copyout((void *)arg, opp, bufsize + sizeof(int));
291		break;
292
293	case OPROMU2P:
294	case OPROMGETCONS:
295	case OPROMGETFBNAME:
296		if (cnt++ < 10)
297			printk(KERN_INFO "openprom_sunos_ioctl: unimplemented ioctl\n");
298		error = -EINVAL;
299		break;
300	default:
301		if (cnt++ < 10)
302			printk(KERN_INFO "openprom_sunos_ioctl: cmd 0x%X, arg 0x%lX\n", cmd, arg);
303		error = -EINVAL;
304		break;
305	}
306
307	kfree(opp);
308	return error;
309}
310
311
312/* Return nonzero if a specific node is in the PROM device tree. */
313static int intree(int root, int node)
314{
315	for (; root != 0; root = prom_getsibling(root))
316		if (root == node || intree(prom_getchild(root),node))
317			return 1;
318	return 0;
319}
320
321/* Return nonzero if a specific node is "valid". */
322static int goodnode(int n, DATA *data)
323{
324	if (n == data->lastnode || n == prom_root_node || n == options_node)
325		return 1;
326	if (n == 0 || n == -1 || !intree(prom_root_node,n))
327		return 0;
328	data->lastnode = n;
329	return 1;
330}
331
332/* Copy in a whole string from userspace into kernelspace. */
333static int copyin_string(char *user, size_t len, char **ptr)
334{
335	char *tmp;
336
337	if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
338		return -EINVAL;
339
340	tmp = kmalloc(len + 1, GFP_KERNEL);
341	if (!tmp)
342		return -ENOMEM;
343
344	if(copy_from_user(tmp, user, len)) {
345		kfree(tmp);
346		return -EFAULT;
347	}
348
349	tmp[len] = '\0';
350
351	*ptr = tmp;
352
353	return 0;
354}
355
356/*
357 *	NetBSD /dev/openprom ioctl calls.
358 */
359static int openprom_bsd_ioctl(struct inode * inode, struct file * file,
360			      unsigned int cmd, unsigned long arg)
361{
362	DATA *data = (DATA *) file->private_data;
363	struct opiocdesc op;
364	unsigned long flags;
365	int error, node, len;
366	char *str, *tmp;
367	char buffer[64];
368	static int cnt;
369
370	switch (cmd) {
371	case OPIOCGET:
372		if (copy_from_user(&op, (void *)arg, sizeof(op)))
373			return -EFAULT;
374
375		if (!goodnode(op.op_nodeid,data))
376			return -EINVAL;
377
378		error = copyin_string(op.op_name, op.op_namelen, &str);
379		if (error)
380			return error;
381
382		save_and_cli(flags);
383		len = prom_getproplen(op.op_nodeid,str);
384		restore_flags(flags);
385
386		if (len > op.op_buflen) {
387			kfree(str);
388			return -ENOMEM;
389		}
390
391		op.op_buflen = len;
392
393		if (len <= 0) {
394			kfree(str);
395			/* Verified by the above copy_from_user */
396			if (__copy_to_user((void *)arg, &op,
397				       sizeof(op)))
398				return -EFAULT;
399			return 0;
400		}
401
402		tmp = kmalloc(len + 1, GFP_KERNEL);
403		if (!tmp) {
404			kfree(str);
405			return -ENOMEM;
406		}
407
408		save_and_cli(flags);
409		prom_getproperty(op.op_nodeid, str, tmp, len);
410		restore_flags(flags);
411
412		tmp[len] = '\0';
413
414		error = __copy_to_user((void *)arg, &op, sizeof(op));
415		if (!error)
416			error = copy_to_user(op.op_buf, tmp, len);
417
418		kfree(tmp);
419		kfree(str);
420
421		return error;
422
423	case OPIOCNEXTPROP:
424		if (copy_from_user(&op, (void *)arg, sizeof(op)))
425			return -EFAULT;
426
427		if (!goodnode(op.op_nodeid,data))
428			return -EINVAL;
429
430		error = copyin_string(op.op_name, op.op_namelen, &str);
431		if (error)
432			return error;
433
434		save_and_cli(flags);
435		tmp = prom_nextprop(op.op_nodeid,str,buffer);
436		restore_flags(flags);
437
438		if (tmp) {
439			len = strlen(tmp);
440			if (len > op.op_buflen)
441				len = op.op_buflen;
442			else
443				op.op_buflen = len;
444		} else {
445			len = op.op_buflen = 0;
446		}
447
448		error = verify_area(VERIFY_WRITE, (void *)arg, sizeof(op));
449		if (error) {
450			kfree(str);
451			return error;
452		}
453
454		error = verify_area(VERIFY_WRITE, op.op_buf, len);
455		if (error) {
456			kfree(str);
457			return error;
458		}
459
460		error = __copy_to_user((void *)arg, &op, sizeof(op));
461		if (!error) error = __copy_to_user(op.op_buf, tmp, len);
462
463		kfree(str);
464
465		return error;
466
467	case OPIOCSET:
468		if (copy_from_user(&op, (void *)arg, sizeof(op)))
469			return -EFAULT;
470
471		if (!goodnode(op.op_nodeid,data))
472			return -EINVAL;
473
474		error = copyin_string(op.op_name, op.op_namelen, &str);
475		if (error)
476			return error;
477
478		error = copyin_string(op.op_buf, op.op_buflen, &tmp);
479		if (error) {
480			kfree(str);
481			return error;
482		}
483
484		save_and_cli(flags);
485		len = prom_setprop(op.op_nodeid,str,tmp,op.op_buflen+1);
486		restore_flags(flags);
487
488		if (len != op.op_buflen)
489			return -EINVAL;
490
491		kfree(str);
492		kfree(tmp);
493
494		return 0;
495
496	case OPIOCGETOPTNODE:
497		if (copy_to_user((void *)arg, &options_node, sizeof(int)))
498			return -EFAULT;
499		return 0;
500
501	case OPIOCGETNEXT:
502	case OPIOCGETCHILD:
503		if (copy_from_user(&node, (void *)arg, sizeof(int)))
504			return -EFAULT;
505
506		save_and_cli(flags);
507		if (cmd == OPIOCGETNEXT)
508			node = __prom_getsibling(node);
509		else
510			node = __prom_getchild(node);
511		restore_flags(flags);
512
513		if (__copy_to_user((void *)arg, &node, sizeof(int)))
514			return -EFAULT;
515
516		return 0;
517
518	default:
519		if (cnt++ < 10)
520			printk(KERN_INFO "openprom_bsd_ioctl: cmd 0x%X\n", cmd);
521		return -EINVAL;
522
523	}
524}
525
526
527/*
528 *	Handoff control to the correct ioctl handler.
529 */
530static int openprom_ioctl(struct inode * inode, struct file * file,
531			  unsigned int cmd, unsigned long arg)
532{
533	DATA *data = (DATA *) file->private_data;
534	static int cnt;
535
536	switch (cmd) {
537	case OPROMGETOPT:
538	case OPROMNXTOPT:
539		if ((file->f_mode & FMODE_READ) == 0)
540			return -EPERM;
541		return openprom_sunos_ioctl(inode, file, cmd, arg,
542					    options_node);
543
544	case OPROMSETOPT:
545	case OPROMSETOPT2:
546		if ((file->f_mode & FMODE_WRITE) == 0)
547			return -EPERM;
548		return openprom_sunos_ioctl(inode, file, cmd, arg,
549					    options_node);
550
551	case OPROMNEXT:
552	case OPROMCHILD:
553	case OPROMGETPROP:
554	case OPROMNXTPROP:
555		if ((file->f_mode & FMODE_READ) == 0)
556			return -EPERM;
557		return openprom_sunos_ioctl(inode, file, cmd, arg,
558					    data->current_node);
559
560	case OPROMU2P:
561	case OPROMGETCONS:
562	case OPROMGETFBNAME:
563	case OPROMGETBOOTARGS:
564	case OPROMSETCUR:
565	case OPROMPCI2NODE:
566	case OPROMPATH2NODE:
567		if ((file->f_mode & FMODE_READ) == 0)
568			return -EPERM;
569		return openprom_sunos_ioctl(inode, file, cmd, arg, 0);
570
571	case OPIOCGET:
572	case OPIOCNEXTPROP:
573	case OPIOCGETOPTNODE:
574	case OPIOCGETNEXT:
575	case OPIOCGETCHILD:
576		if ((file->f_mode & FMODE_READ) == 0)
577			return -EBADF;
578		return openprom_bsd_ioctl(inode,file,cmd,arg);
579
580	case OPIOCSET:
581		if ((file->f_mode & FMODE_WRITE) == 0)
582			return -EBADF;
583		return openprom_bsd_ioctl(inode,file,cmd,arg);
584
585	default:
586		if (cnt++ < 10)
587			printk("openprom_ioctl: cmd 0x%X, arg 0x%lX\n", cmd, arg);
588		return -EINVAL;
589	}
590}
591
592static int openprom_open(struct inode * inode, struct file * file)
593{
594	DATA *data;
595
596	data = (DATA *) kmalloc(sizeof(DATA), GFP_KERNEL);
597	if (!data)
598		return -ENOMEM;
599
600	data->current_node = prom_root_node;
601	data->lastnode = prom_root_node;
602	file->private_data = (void *)data;
603
604	return 0;
605}
606
607static int openprom_release(struct inode * inode, struct file * file)
608{
609	kfree(file->private_data);
610	return 0;
611}
612
613static struct file_operations openprom_fops = {
614	owner:		THIS_MODULE,
615	llseek:		no_llseek,
616	ioctl:		openprom_ioctl,
617	open:		openprom_open,
618	release:	openprom_release,
619};
620
621static struct miscdevice openprom_dev = {
622	SUN_OPENPROM_MINOR, "openprom", &openprom_fops
623};
624
625EXPORT_NO_SYMBOLS;
626
627static int __init openprom_init(void)
628{
629	unsigned long flags;
630	int error;
631
632	error = misc_register(&openprom_dev);
633	if (error) {
634		printk(KERN_ERR "openprom: unable to get misc minor\n");
635		return error;
636	}
637
638	save_and_cli(flags);
639	options_node = prom_getchild(prom_root_node);
640	options_node = prom_searchsiblings(options_node,"options");
641	restore_flags(flags);
642
643	if (options_node == 0 || options_node == -1) {
644		printk(KERN_ERR "openprom: unable to find options node\n");
645		misc_deregister(&openprom_dev);
646		return -EIO;
647	}
648
649	return 0;
650}
651
652static void __exit openprom_cleanup(void)
653{
654	misc_deregister(&openprom_dev);
655}
656
657module_init(openprom_init);
658module_exit(openprom_cleanup);
659MODULE_LICENSE("GPL");
660