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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Linux/SPARC PROM Configuration Driver4 * Copyright (C) 1996 Thomas K. Dyas (tdyas@noc.rutgers.edu)5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)6 *7 * This character device driver allows user programs to access the8 * PROM device tree. It is compatible with the SunOS /dev/openprom9 * driver and the NetBSD /dev/openprom driver. The SunOS eeprom10 * utility works without any modifications.11 *12 * The driver uses a minor number under the misc device major. The13 * file read/write mode determines the type of access to the PROM.14 * Interrupts are disabled whenever the driver calls into the PROM for15 * sanity's sake.16 */17 18 19#include <linux/module.h>20#include <linux/kernel.h>21#include <linux/errno.h>22#include <linux/slab.h>23#include <linux/mutex.h>24#include <linux/string.h>25#include <linux/miscdevice.h>26#include <linux/init.h>27#include <linux/fs.h>28#include <asm/oplib.h>29#include <asm/prom.h>30#include <linux/uaccess.h>31#include <asm/openpromio.h>32#ifdef CONFIG_PCI33#include <linux/pci.h>34#endif35 36MODULE_AUTHOR("Thomas K. Dyas <tdyas@noc.rutgers.edu> and Eddie C. Dost <ecd@skynet.be>");37MODULE_DESCRIPTION("OPENPROM Configuration Driver");38MODULE_LICENSE("GPL");39MODULE_VERSION("1.0");40MODULE_ALIAS_MISCDEV(SUN_OPENPROM_MINOR);41 42/* Private data kept by the driver for each descriptor. */43typedef struct openprom_private_data44{45 struct device_node *current_node; /* Current node for SunOS ioctls. */46 struct device_node *lastnode; /* Last valid node used by BSD ioctls. */47} DATA;48 49/* ID of the PROM node containing all of the EEPROM options. */50static DEFINE_MUTEX(openprom_mutex);51static struct device_node *options_node;52 53/*54 * Copy an openpromio structure into kernel space from user space.55 * This routine does error checking to make sure that all memory56 * accesses are within bounds. A pointer to the allocated openpromio57 * structure will be placed in "*opp_p". Return value is the length58 * of the user supplied buffer.59 */60static int copyin(struct openpromio __user *info, struct openpromio **opp_p)61{62 unsigned int bufsize;63 64 if (!info || !opp_p)65 return -EFAULT;66 67 if (get_user(bufsize, &info->oprom_size))68 return -EFAULT;69 70 if (bufsize == 0)71 return -EINVAL;72 73 /* If the bufsize is too large, just limit it.74 * Fix from Jason Rappleye.75 */76 if (bufsize > OPROMMAXPARAM)77 bufsize = OPROMMAXPARAM;78 79 if (!(*opp_p = kzalloc(sizeof(int) + bufsize + 1, GFP_KERNEL)))80 return -ENOMEM;81 82 if (copy_from_user(&(*opp_p)->oprom_array,83 &info->oprom_array, bufsize)) {84 kfree(*opp_p);85 return -EFAULT;86 }87 return bufsize;88}89 90static int getstrings(struct openpromio __user *info, struct openpromio **opp_p)91{92 int n, bufsize;93 char c;94 95 if (!info || !opp_p)96 return -EFAULT;97 98 if (!(*opp_p = kzalloc(sizeof(int) + OPROMMAXPARAM + 1, GFP_KERNEL)))99 return -ENOMEM;100 101 (*opp_p)->oprom_size = 0;102 103 n = bufsize = 0;104 while ((n < 2) && (bufsize < OPROMMAXPARAM)) {105 if (get_user(c, &info->oprom_array[bufsize])) {106 kfree(*opp_p);107 return -EFAULT;108 }109 if (c == '\0')110 n++;111 (*opp_p)->oprom_array[bufsize++] = c;112 }113 if (!n) {114 kfree(*opp_p);115 return -EINVAL;116 }117 return bufsize;118}119 120/*121 * Copy an openpromio structure in kernel space back to user space.122 */123static int copyout(void __user *info, struct openpromio *opp, int len)124{125 if (copy_to_user(info, opp, len))126 return -EFAULT;127 return 0;128}129 130static int opromgetprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)131{132 const void *pval;133 int len;134 135 if (!dp ||136 !(pval = of_get_property(dp, op->oprom_array, &len)) ||137 len <= 0 || len > bufsize)138 return copyout(argp, op, sizeof(int));139 140 memcpy(op->oprom_array, pval, len);141 op->oprom_array[len] = '\0';142 op->oprom_size = len;143 144 return copyout(argp, op, sizeof(int) + bufsize);145}146 147static int opromnxtprop(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize)148{149 struct property *prop;150 int len;151 152 if (!dp)153 return copyout(argp, op, sizeof(int));154 if (op->oprom_array[0] == '\0') {155 prop = dp->properties;156 if (!prop)157 return copyout(argp, op, sizeof(int));158 len = strlen(prop->name);159 } else {160 prop = of_find_property(dp, op->oprom_array, NULL);161 162 if (!prop ||163 !prop->next ||164 (len = strlen(prop->next->name)) + 1 > bufsize)165 return copyout(argp, op, sizeof(int));166 167 prop = prop->next;168 }169 170 memcpy(op->oprom_array, prop->name, len);171 op->oprom_array[len] = '\0';172 op->oprom_size = ++len;173 174 return copyout(argp, op, sizeof(int) + bufsize);175}176 177static int opromsetopt(struct device_node *dp, struct openpromio *op, int bufsize)178{179 char *buf = op->oprom_array + strlen(op->oprom_array) + 1;180 int len = op->oprom_array + bufsize - buf;181 182 return of_set_property(options_node, op->oprom_array, buf, len);183}184 185static int opromnext(void __user *argp, unsigned int cmd, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)186{187 phandle ph;188 189 BUILD_BUG_ON(sizeof(phandle) != sizeof(int));190 191 if (bufsize < sizeof(phandle))192 return -EINVAL;193 194 ph = *((int *) op->oprom_array);195 if (ph) {196 dp = of_find_node_by_phandle(ph);197 if (!dp)198 return -EINVAL;199 200 switch (cmd) {201 case OPROMNEXT:202 dp = dp->sibling;203 break;204 205 case OPROMCHILD:206 dp = dp->child;207 break;208 209 case OPROMSETCUR:210 default:211 break;212 }213 } else {214 /* Sibling of node zero is the root node. */215 if (cmd != OPROMNEXT)216 return -EINVAL;217 218 dp = of_find_node_by_path("/");219 }220 221 ph = 0;222 if (dp)223 ph = dp->phandle;224 225 data->current_node = dp;226 *((int *) op->oprom_array) = ph;227 op->oprom_size = sizeof(phandle);228 229 return copyout(argp, op, bufsize + sizeof(int));230}231 232static int oprompci2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)233{234 int err = -EINVAL;235 236 if (bufsize >= 2*sizeof(int)) {237#ifdef CONFIG_PCI238 struct pci_dev *pdev;239 struct device_node *dp;240 241 pdev = pci_get_domain_bus_and_slot(0,242 ((int *) op->oprom_array)[0],243 ((int *) op->oprom_array)[1]);244 245 dp = pci_device_to_OF_node(pdev);246 data->current_node = dp;247 *((int *)op->oprom_array) = dp->phandle;248 op->oprom_size = sizeof(int);249 err = copyout(argp, op, bufsize + sizeof(int));250 251 pci_dev_put(pdev);252#endif253 }254 255 return err;256}257 258static int oprompath2node(void __user *argp, struct device_node *dp, struct openpromio *op, int bufsize, DATA *data)259{260 phandle ph = 0;261 262 dp = of_find_node_by_path(op->oprom_array);263 if (dp)264 ph = dp->phandle;265 data->current_node = dp;266 *((int *)op->oprom_array) = ph;267 op->oprom_size = sizeof(int);268 269 return copyout(argp, op, bufsize + sizeof(int));270}271 272static int opromgetbootargs(void __user *argp, struct openpromio *op, int bufsize)273{274 char *buf = saved_command_line;275 int len = strlen(buf);276 277 if (len > bufsize)278 return -EINVAL;279 280 strcpy(op->oprom_array, buf);281 op->oprom_size = len;282 283 return copyout(argp, op, bufsize + sizeof(int));284}285 286/*287 * SunOS and Solaris /dev/openprom ioctl calls.288 */289static long openprom_sunos_ioctl(struct file * file,290 unsigned int cmd, unsigned long arg,291 struct device_node *dp)292{293 DATA *data = file->private_data;294 struct openpromio *opp = NULL;295 int bufsize, error = 0;296 static int cnt;297 void __user *argp = (void __user *)arg;298 299 if (cmd == OPROMSETOPT)300 bufsize = getstrings(argp, &opp);301 else302 bufsize = copyin(argp, &opp);303 304 if (bufsize < 0)305 return bufsize;306 307 mutex_lock(&openprom_mutex);308 309 switch (cmd) {310 case OPROMGETOPT:311 case OPROMGETPROP:312 error = opromgetprop(argp, dp, opp, bufsize);313 break;314 315 case OPROMNXTOPT:316 case OPROMNXTPROP:317 error = opromnxtprop(argp, dp, opp, bufsize);318 break;319 320 case OPROMSETOPT:321 case OPROMSETOPT2:322 error = opromsetopt(dp, opp, bufsize);323 break;324 325 case OPROMNEXT:326 case OPROMCHILD:327 case OPROMSETCUR:328 error = opromnext(argp, cmd, dp, opp, bufsize, data);329 break;330 331 case OPROMPCI2NODE:332 error = oprompci2node(argp, dp, opp, bufsize, data);333 break;334 335 case OPROMPATH2NODE:336 error = oprompath2node(argp, dp, opp, bufsize, data);337 break;338 339 case OPROMGETBOOTARGS:340 error = opromgetbootargs(argp, opp, bufsize);341 break;342 343 case OPROMU2P:344 case OPROMGETCONS:345 case OPROMGETFBNAME:346 if (cnt++ < 10)347 printk(KERN_INFO "openprom_sunos_ioctl: unimplemented ioctl\n");348 error = -EINVAL;349 break;350 default:351 if (cnt++ < 10)352 printk(KERN_INFO "openprom_sunos_ioctl: cmd 0x%X, arg 0x%lX\n", cmd, arg);353 error = -EINVAL;354 break;355 }356 357 kfree(opp);358 mutex_unlock(&openprom_mutex);359 360 return error;361}362 363static struct device_node *get_node(phandle n, DATA *data)364{365 struct device_node *dp = of_find_node_by_phandle(n);366 367 if (dp)368 data->lastnode = dp;369 370 return dp;371}372 373/* Copy in a whole string from userspace into kernelspace. */374static char * copyin_string(char __user *user, size_t len)375{376 if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)377 return ERR_PTR(-EINVAL);378 379 return memdup_user_nul(user, len);380}381 382/*383 * NetBSD /dev/openprom ioctl calls.384 */385static int opiocget(void __user *argp, DATA *data)386{387 struct opiocdesc op;388 struct device_node *dp;389 char *str;390 const void *pval;391 int err, len;392 393 if (copy_from_user(&op, argp, sizeof(op)))394 return -EFAULT;395 396 dp = get_node(op.op_nodeid, data);397 398 str = copyin_string(op.op_name, op.op_namelen);399 if (IS_ERR(str))400 return PTR_ERR(str);401 402 pval = of_get_property(dp, str, &len);403 err = 0;404 if (!pval || len > op.op_buflen) {405 err = -EINVAL;406 } else {407 op.op_buflen = len;408 if (copy_to_user(argp, &op, sizeof(op)) ||409 copy_to_user(op.op_buf, pval, len))410 err = -EFAULT;411 }412 kfree(str);413 414 return err;415}416 417static int opiocnextprop(void __user *argp, DATA *data)418{419 struct opiocdesc op;420 struct device_node *dp;421 struct property *prop;422 char *str;423 int len;424 425 if (copy_from_user(&op, argp, sizeof(op)))426 return -EFAULT;427 428 dp = get_node(op.op_nodeid, data);429 if (!dp)430 return -EINVAL;431 432 str = copyin_string(op.op_name, op.op_namelen);433 if (IS_ERR(str))434 return PTR_ERR(str);435 436 if (str[0] == '\0') {437 prop = dp->properties;438 } else {439 prop = of_find_property(dp, str, NULL);440 if (prop)441 prop = prop->next;442 }443 kfree(str);444 445 if (!prop)446 len = 0;447 else448 len = prop->length;449 450 if (len > op.op_buflen)451 len = op.op_buflen;452 453 if (copy_to_user(argp, &op, sizeof(op)))454 return -EFAULT;455 456 if (len &&457 copy_to_user(op.op_buf, prop->value, len))458 return -EFAULT;459 460 return 0;461}462 463static int opiocset(void __user *argp, DATA *data)464{465 struct opiocdesc op;466 struct device_node *dp;467 char *str, *tmp;468 int err;469 470 if (copy_from_user(&op, argp, sizeof(op)))471 return -EFAULT;472 473 dp = get_node(op.op_nodeid, data);474 if (!dp)475 return -EINVAL;476 477 str = copyin_string(op.op_name, op.op_namelen);478 if (IS_ERR(str))479 return PTR_ERR(str);480 481 tmp = copyin_string(op.op_buf, op.op_buflen);482 if (IS_ERR(tmp)) {483 kfree(str);484 return PTR_ERR(tmp);485 }486 487 err = of_set_property(dp, str, tmp, op.op_buflen);488 489 kfree(str);490 kfree(tmp);491 492 return err;493}494 495static int opiocgetnext(unsigned int cmd, void __user *argp)496{497 struct device_node *dp;498 phandle nd;499 500 BUILD_BUG_ON(sizeof(phandle) != sizeof(int));501 502 if (copy_from_user(&nd, argp, sizeof(phandle)))503 return -EFAULT;504 505 if (nd == 0) {506 if (cmd != OPIOCGETNEXT)507 return -EINVAL;508 dp = of_find_node_by_path("/");509 } else {510 dp = of_find_node_by_phandle(nd);511 nd = 0;512 if (dp) {513 if (cmd == OPIOCGETNEXT)514 dp = dp->sibling;515 else516 dp = dp->child;517 }518 }519 if (dp)520 nd = dp->phandle;521 if (copy_to_user(argp, &nd, sizeof(phandle)))522 return -EFAULT;523 524 return 0;525}526 527static int openprom_bsd_ioctl(struct file * file,528 unsigned int cmd, unsigned long arg)529{530 DATA *data = file->private_data;531 void __user *argp = (void __user *)arg;532 int err;533 534 mutex_lock(&openprom_mutex);535 switch (cmd) {536 case OPIOCGET:537 err = opiocget(argp, data);538 break;539 540 case OPIOCNEXTPROP:541 err = opiocnextprop(argp, data);542 break;543 544 case OPIOCSET:545 err = opiocset(argp, data);546 break;547 548 case OPIOCGETOPTNODE:549 BUILD_BUG_ON(sizeof(phandle) != sizeof(int));550 551 err = 0;552 if (copy_to_user(argp, &options_node->phandle, sizeof(phandle)))553 err = -EFAULT;554 break;555 556 case OPIOCGETNEXT:557 case OPIOCGETCHILD:558 err = opiocgetnext(cmd, argp);559 break;560 561 default:562 err = -EINVAL;563 break;564 }565 mutex_unlock(&openprom_mutex);566 567 return err;568}569 570 571/*572 * Handoff control to the correct ioctl handler.573 */574static long openprom_ioctl(struct file * file,575 unsigned int cmd, unsigned long arg)576{577 DATA *data = file->private_data;578 579 switch (cmd) {580 case OPROMGETOPT:581 case OPROMNXTOPT:582 if ((file->f_mode & FMODE_READ) == 0)583 return -EPERM;584 return openprom_sunos_ioctl(file, cmd, arg,585 options_node);586 587 case OPROMSETOPT:588 case OPROMSETOPT2:589 if ((file->f_mode & FMODE_WRITE) == 0)590 return -EPERM;591 return openprom_sunos_ioctl(file, cmd, arg,592 options_node);593 594 case OPROMNEXT:595 case OPROMCHILD:596 case OPROMGETPROP:597 case OPROMNXTPROP:598 if ((file->f_mode & FMODE_READ) == 0)599 return -EPERM;600 return openprom_sunos_ioctl(file, cmd, arg,601 data->current_node);602 603 case OPROMU2P:604 case OPROMGETCONS:605 case OPROMGETFBNAME:606 case OPROMGETBOOTARGS:607 case OPROMSETCUR:608 case OPROMPCI2NODE:609 case OPROMPATH2NODE:610 if ((file->f_mode & FMODE_READ) == 0)611 return -EPERM;612 return openprom_sunos_ioctl(file, cmd, arg, NULL);613 614 case OPIOCGET:615 case OPIOCNEXTPROP:616 case OPIOCGETOPTNODE:617 case OPIOCGETNEXT:618 case OPIOCGETCHILD:619 if ((file->f_mode & FMODE_READ) == 0)620 return -EBADF;621 return openprom_bsd_ioctl(file,cmd,arg);622 623 case OPIOCSET:624 if ((file->f_mode & FMODE_WRITE) == 0)625 return -EBADF;626 return openprom_bsd_ioctl(file,cmd,arg);627 628 default:629 return -EINVAL;630 };631}632 633static long openprom_compat_ioctl(struct file *file, unsigned int cmd,634 unsigned long arg)635{636 long rval = -ENOTTY;637 638 /*639 * SunOS/Solaris only, the NetBSD one's have embedded pointers in640 * the arg which we'd need to clean up...641 */642 switch (cmd) {643 case OPROMGETOPT:644 case OPROMSETOPT:645 case OPROMNXTOPT:646 case OPROMSETOPT2:647 case OPROMNEXT:648 case OPROMCHILD:649 case OPROMGETPROP:650 case OPROMNXTPROP:651 case OPROMU2P:652 case OPROMGETCONS:653 case OPROMGETFBNAME:654 case OPROMGETBOOTARGS:655 case OPROMSETCUR:656 case OPROMPCI2NODE:657 case OPROMPATH2NODE:658 rval = openprom_ioctl(file, cmd, arg);659 break;660 }661 662 return rval;663}664 665static int openprom_open(struct inode * inode, struct file * file)666{667 DATA *data;668 669 data = kmalloc(sizeof(DATA), GFP_KERNEL);670 if (!data)671 return -ENOMEM;672 673 mutex_lock(&openprom_mutex);674 data->current_node = of_find_node_by_path("/");675 data->lastnode = data->current_node;676 file->private_data = (void *) data;677 mutex_unlock(&openprom_mutex);678 679 return 0;680}681 682static int openprom_release(struct inode * inode, struct file * file)683{684 kfree(file->private_data);685 return 0;686}687 688static const struct file_operations openprom_fops = {689 .owner = THIS_MODULE,690 .unlocked_ioctl = openprom_ioctl,691 .compat_ioctl = openprom_compat_ioctl,692 .open = openprom_open,693 .release = openprom_release,694};695 696static struct miscdevice openprom_dev = {697 .minor = SUN_OPENPROM_MINOR,698 .name = "openprom",699 .fops = &openprom_fops,700};701 702static int __init openprom_init(void)703{704 int err;705 706 err = misc_register(&openprom_dev);707 if (err)708 return err;709 710 options_node = of_get_child_by_name(of_find_node_by_path("/"), "options");711 if (!options_node) {712 misc_deregister(&openprom_dev);713 return -EIO;714 }715 716 return 0;717}718 719static void __exit openprom_cleanup(void)720{721 misc_deregister(&openprom_dev);722}723 724module_init(openprom_init);725module_exit(openprom_cleanup);726