Annotation of prex-old/sys/kern/device.c, Revision 1.1
1.1 ! nbrk 1: /*-
! 2: * Copyright (c) 2005-2007, Kohsuke Ohtani
! 3: * All rights reserved.
! 4: *
! 5: * Redistribution and use in source and binary forms, with or without
! 6: * modification, are permitted provided that the following conditions
! 7: * are met:
! 8: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. Neither the name of the author nor the names of any co-contributors
! 14: * may be used to endorse or promote products derived from this software
! 15: * without specific prior written permission.
! 16: *
! 17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
! 18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
! 21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 27: * SUCH DAMAGE.
! 28: */
! 29:
! 30: /*
! 31: * device.c - device I/O support routines
! 32: */
! 33:
! 34: /*
! 35: * The device_* system calls are interfaces for user mode applications
! 36: * to access the specific device object which is handled by the related
! 37: * device driver. A device driver is an execution module different from
! 38: * a kernel on Prex. The routines in this file have the following role
! 39: * to handle the device I/O.
! 40: *
! 41: * - Manage the name space for device objects.
! 42: * - Forward user I/O requests to the drivers after checking parameters.
! 43: *
! 44: * The driver module(s) and kernel are dynamically linked at system boot.
! 45: */
! 46:
! 47: #include <kernel.h>
! 48: #include <irq.h>
! 49: #include <page.h>
! 50: #include <kmem.h>
! 51: #include <task.h>
! 52: #include <timer.h>
! 53: #include <sched.h>
! 54: #include <exception.h>
! 55: #include <vm.h>
! 56: #include <device.h>
! 57: #include <system.h>
! 58:
! 59: /* forward declarations */
! 60: static device_t device_create(struct devio *, const char *, int);
! 61: static int device_destroy(device_t);
! 62: static int device_broadcast(int, int);
! 63: static void machine_bootinfo(struct boot_info **);
! 64: static void machine__reset(void);
! 65: static void machine__idle(void);
! 66: static int task__capable(cap_t cap);
! 67: static void *phys__to_virt(void *);
! 68: static void *virt__to_phys(void *);
! 69:
! 70: #ifndef DEBUG
! 71: static void nosys(void);
! 72: #undef printk
! 73: #define printk nosys
! 74:
! 75: #undef panic
! 76: #define panic machine_reset
! 77: #endif
! 78:
! 79: typedef void (*dkifn_t)(void);
! 80:
! 81: #define DKIENT(func) (dkifn_t)(func)
! 82:
! 83: /*
! 84: * Driver-Kernel Interface (DKI)
! 85: */
! 86: static const dkifn_t driver_service[] = {
! 87: /* 0 */ DKIENT(device_create),
! 88: /* 1 */ DKIENT(device_destroy),
! 89: /* 2 */ DKIENT(device_broadcast),
! 90: /* 3 */ DKIENT(umem_copyin),
! 91: /* 4 */ DKIENT(umem_copyout),
! 92: /* 5 */ DKIENT(umem_strnlen),
! 93: /* 6 */ DKIENT(kmem_alloc),
! 94: /* 7 */ DKIENT(kmem_free),
! 95: /* 8 */ DKIENT(kmem_map),
! 96: /* 9 */ DKIENT(page_alloc),
! 97: /* 10 */ DKIENT(page_free),
! 98: /* 11 */ DKIENT(page_reserve),
! 99: /* 12 */ DKIENT(irq_attach),
! 100: /* 13 */ DKIENT(irq_detach),
! 101: /* 14 */ DKIENT(irq_lock),
! 102: /* 15 */ DKIENT(irq_unlock),
! 103: /* 16 */ DKIENT(timer_callout),
! 104: /* 17 */ DKIENT(timer_stop),
! 105: /* 18 */ DKIENT(timer_delay),
! 106: /* 19 */ DKIENT(timer_count),
! 107: /* 20 */ DKIENT(timer_hook),
! 108: /* 21 */ DKIENT(sched_lock),
! 109: /* 22 */ DKIENT(sched_unlock),
! 110: /* 23 */ DKIENT(sched_tsleep),
! 111: /* 24 */ DKIENT(sched_wakeup),
! 112: /* 25 */ DKIENT(sched_dpc),
! 113: /* 26 */ DKIENT(task__capable),
! 114: /* 27 */ DKIENT(exception_post),
! 115: /* 28 */ DKIENT(machine_bootinfo),
! 116: /* 29 */ DKIENT(machine__reset),
! 117: /* 30 */ DKIENT(machine__idle),
! 118: /* 31 */ DKIENT(phys__to_virt),
! 119: /* 32 */ DKIENT(virt__to_phys),
! 120: /* 33 */ DKIENT(debug_attach),
! 121: /* 34 */ DKIENT(debug_dump),
! 122: /* 35 */ DKIENT(printk),
! 123: /* 36 */ DKIENT(panic),
! 124: };
! 125:
! 126: static struct list device_list; /* list of the device objects */
! 127:
! 128: /*
! 129: * Increment reference count on an active device.
! 130: * This routine checks whether the specified device is valid.
! 131: * It returns 0 on success, or -1 on failure.
! 132: */
! 133: static int
! 134: device_hold(device_t dev)
! 135: {
! 136: int err = -1;
! 137:
! 138: sched_lock();
! 139: if (device_valid(dev)) {
! 140: dev->ref_count++;
! 141: err = 0;
! 142: }
! 143: sched_unlock();
! 144: return err;
! 145: }
! 146:
! 147: /*
! 148: * Decrement the reference count on a device. If the reference
! 149: * count becomes zero, we can release the resource for the
! 150: * target device. Assumes the device is already validated by caller.
! 151: */
! 152: static void
! 153: device_release(device_t dev)
! 154: {
! 155:
! 156: sched_lock();
! 157: if (--dev->ref_count == 0) {
! 158: list_remove(&dev->link);
! 159: kmem_free(dev);
! 160: }
! 161: sched_unlock();
! 162: }
! 163:
! 164: /*
! 165: * Look up a device object by device name.
! 166: * Return device ID on success, or NULL on failure.
! 167: * This must be called with scheduler locked.
! 168: */
! 169: static device_t
! 170: device_lookup(const char *name)
! 171: {
! 172: list_t head, n;
! 173: device_t dev;
! 174:
! 175: if (name == NULL)
! 176: return NULL;
! 177:
! 178: head = &device_list;
! 179: for (n = list_first(head); n != head; n = list_next(n)) {
! 180: dev = list_entry(n, struct device, link);
! 181: if (!strncmp(dev->name, name, MAXDEVNAME))
! 182: return dev;
! 183: }
! 184: return NULL;
! 185: }
! 186:
! 187: /*
! 188: * device_create - create new device object.
! 189: * @io: pointer to device I/O routines
! 190: * @name: string for device name
! 191: * @flags: flags for device object. (ex. block or character)
! 192: *
! 193: * A device object is created by the device driver to provide
! 194: * I/O services to applications.
! 195: * Returns device ID on success, or 0 on failure.
! 196: */
! 197: static device_t
! 198: device_create(struct devio *io, const char *name, int flags)
! 199: {
! 200: device_t dev;
! 201: size_t len;
! 202:
! 203: ASSERT(irq_level == 0);
! 204:
! 205: len = strnlen(name, MAXDEVNAME);
! 206: if (len == 0 || len >= MAXDEVNAME) /* Invalid name? */
! 207: return 0;
! 208:
! 209: sched_lock();
! 210: if ((dev = device_lookup(name)) != NULL) {
! 211: /*
! 212: * Error - the device name is already used.
! 213: */
! 214: sched_unlock();
! 215: return 0;
! 216: }
! 217: if ((dev = kmem_alloc(sizeof(struct device))) == NULL) {
! 218: sched_unlock();
! 219: return 0;
! 220: }
! 221: strlcpy(dev->name, name, len + 1);
! 222: dev->devio = io;
! 223: dev->flags = flags;
! 224: dev->ref_count = 1;
! 225: dev->magic = DEVICE_MAGIC;
! 226: list_insert(&device_list, &dev->link);
! 227: sched_unlock();
! 228: return dev;
! 229: }
! 230:
! 231: /*
! 232: * Destroy a device object. If some other threads still refer
! 233: * the target device, the destroy operating will be pending
! 234: * until its reference count becomes 0.
! 235: */
! 236: static int
! 237: device_destroy(device_t dev)
! 238: {
! 239: int err = 0;
! 240:
! 241: ASSERT(irq_level == 0);
! 242:
! 243: sched_lock();
! 244: if (device_valid(dev))
! 245: device_release(dev);
! 246: else
! 247: err = ENODEV;
! 248: sched_unlock();
! 249: return err;
! 250: }
! 251:
! 252: /*
! 253: * device_open - open the specified device.
! 254: * @name: device name (null-terminated)
! 255: * @mode: open mode. (like O_RDONLY etc.)
! 256: * @devp: device handle of opened device to be returned.
! 257: *
! 258: * Even if the target driver does not have an open routine, this
! 259: * function does not return an error. By using this mechanism, an
! 260: * application can check whether the specific device exists or not.
! 261: * The open mode should be handled by an each device driver if it
! 262: * is needed.
! 263: */
! 264: int
! 265: device_open(const char *name, int mode, device_t *devp)
! 266: {
! 267: char str[MAXDEVNAME];
! 268: device_t dev;
! 269: size_t len;
! 270: int err = 0;
! 271:
! 272: if (!task_capable(CAP_DEVIO))
! 273: return EPERM;
! 274:
! 275: if (umem_strnlen(name, MAXDEVNAME, &len))
! 276: return EFAULT;
! 277: if (len == 0)
! 278: return ENOENT;
! 279: if (len >= MAXDEVNAME)
! 280: return ENAMETOOLONG;
! 281:
! 282: if (umem_copyin((void *)name, str, len + 1))
! 283: return EFAULT;
! 284:
! 285: sched_lock();
! 286: if ((dev = device_lookup(str)) == NULL) {
! 287: sched_unlock();
! 288: return ENXIO;
! 289: }
! 290: device_hold(dev);
! 291: sched_unlock();
! 292:
! 293: if (dev->devio->open != NULL)
! 294: err = (dev->devio->open)(dev, mode);
! 295:
! 296: if (!err)
! 297: err = umem_copyout(&dev, devp, sizeof(device_t));
! 298: device_release(dev);
! 299: return err;
! 300: }
! 301:
! 302: /*
! 303: * device_close - close a device.
! 304: *
! 305: * Even if the target driver does not have close routine,
! 306: * this function does not return any errors.
! 307: */
! 308: int
! 309: device_close(device_t dev)
! 310: {
! 311: int err = 0;
! 312:
! 313: if (!task_capable(CAP_DEVIO))
! 314: return EPERM;
! 315:
! 316: if (device_hold(dev))
! 317: return ENODEV;
! 318:
! 319: if (dev->devio->close != NULL)
! 320: err = (dev->devio->close)(dev);
! 321:
! 322: device_release(dev);
! 323: return err;
! 324: }
! 325:
! 326: /*
! 327: * device_read - read from a device.
! 328: * @dev: device id
! 329: * @buf: pointer to read buffer
! 330: * @nbyte: number of bytes to read. actual read count is set in return.
! 331: * @blkno: block number (for block device)
! 332: *
! 333: * Note: The size of one block is device dependent.
! 334: */
! 335: int
! 336: device_read(device_t dev, void *buf, size_t *nbyte, int blkno)
! 337: {
! 338: size_t count;
! 339: int err;
! 340:
! 341: if (!task_capable(CAP_DEVIO))
! 342: return EPERM;
! 343:
! 344: if (device_hold(dev))
! 345: return ENODEV;
! 346:
! 347: if (dev->devio->read == NULL) {
! 348: device_release(dev);
! 349: return EBADF;
! 350: }
! 351: if (umem_copyin(nbyte, &count, sizeof(u_long)) ||
! 352: vm_access(buf, count, VMA_WRITE)) {
! 353: device_release(dev);
! 354: return EFAULT;
! 355: }
! 356: err = (dev->devio->read)(dev, buf, &count, blkno);
! 357: if (err == 0)
! 358: err = umem_copyout(&count, nbyte, sizeof(u_long));
! 359: device_release(dev);
! 360: return err;
! 361: }
! 362:
! 363: /*
! 364: * device_write - write to a device.
! 365: * @dev: device id
! 366: * @buf: pointer to write buffer
! 367: * @nbyte: number of bytes to write. actual write count is set in return.
! 368: * @blkno: block number (for block device)
! 369: */
! 370: int
! 371: device_write(device_t dev, void *buf, size_t *nbyte, int blkno)
! 372: {
! 373: size_t count;
! 374: int err;
! 375:
! 376: if (!task_capable(CAP_DEVIO))
! 377: return EPERM;
! 378:
! 379: if (device_hold(dev))
! 380: return ENODEV;
! 381:
! 382: if (dev->devio->write == NULL) {
! 383: device_release(dev);
! 384: return EBADF;
! 385: }
! 386: if (umem_copyin(nbyte, &count, sizeof(u_long)) ||
! 387: vm_access(buf, count, VMA_READ)) {
! 388: device_release(dev);
! 389: return EFAULT;
! 390: }
! 391: err = (dev->devio->write)(dev, buf, &count, blkno);
! 392: if (err == 0)
! 393: err = umem_copyout(&count, nbyte, sizeof(u_long));
! 394:
! 395: device_release(dev);
! 396: return err;
! 397: }
! 398:
! 399: /*
! 400: * deivce_ioctl - I/O control request.
! 401: * @dev: device id
! 402: * @cmd: command
! 403: * @arg: argument
! 404: *
! 405: * A command and an argument are completely device dependent.
! 406: * If argument type is pointer, the driver routine must validate
! 407: * the pointer address.
! 408: */
! 409: int
! 410: device_ioctl(device_t dev, int cmd, u_long arg)
! 411: {
! 412: int err;
! 413:
! 414: if (!task_capable(CAP_DEVIO))
! 415: return EPERM;
! 416:
! 417: if (device_hold(dev))
! 418: return ENODEV;
! 419:
! 420: err = EBADF;
! 421: if (dev->devio->ioctl != NULL)
! 422: err = (dev->devio->ioctl)(dev, cmd, arg);
! 423:
! 424: device_release(dev);
! 425: return err;
! 426: }
! 427:
! 428: /*
! 429: * device_broadcast - broadcast an event to all device objects.
! 430: * @event: event code
! 431: * @force: true to ignore the return value from driver.
! 432: *
! 433: * If force argument is true, a kernel will continue event
! 434: * notification even if some driver returns error. In this case,
! 435: * this routine returns EIO error if at least one driver returns
! 436: * an error.
! 437: *
! 438: * If force argument is false, a kernel stops the event processing
! 439: * when at least one driver returns an error. In this case,
! 440: * device_broadcast will return the error code which is returned
! 441: * by the driver.
! 442: */
! 443: static int
! 444: device_broadcast(int event, int force)
! 445: {
! 446: device_t dev;
! 447: list_t head, n;
! 448: int err, ret = 0;
! 449:
! 450: sched_lock();
! 451: head = &device_list;
! 452:
! 453: #ifdef DEBUG
! 454: printk("Broadcasting device event:%d\n", event);
! 455: #endif
! 456: for (n = list_first(head); n != head; n = list_next(n)) {
! 457: dev = list_entry(n, struct device, link);
! 458: if (dev->devio->event == NULL)
! 459: continue;
! 460:
! 461: err = (dev->devio->event)(event);
! 462: if (err) {
! 463: if (force)
! 464: ret = EIO;
! 465: else {
! 466: ret = err;
! 467: break;
! 468: }
! 469: }
! 470: }
! 471: sched_unlock();
! 472: return ret;
! 473: }
! 474:
! 475: /*
! 476: * Return device information (for devfs).
! 477: */
! 478: int
! 479: device_info(struct info_device *info)
! 480: {
! 481: u_long index, target = info->cookie;
! 482: device_t dev;
! 483: struct devio *io;
! 484: list_t head, n;
! 485:
! 486: sched_lock();
! 487:
! 488: index = 0;
! 489: head = &device_list;
! 490: for (n = list_first(head); n != head; n = list_next(n), index++) {
! 491: dev = list_entry(n, struct device, link);
! 492: io = dev->devio;
! 493: if (index == target)
! 494: break;
! 495: }
! 496: if (n == head) {
! 497: sched_unlock();
! 498: return ESRCH;
! 499: }
! 500: info->id = dev;
! 501: info->flags = dev->flags;
! 502: strlcpy(info->name, dev->name, MAXDEVNAME);
! 503:
! 504: sched_unlock();
! 505: return 0;
! 506: }
! 507:
! 508: #if defined(DEBUG) && defined(CONFIG_KDUMP)
! 509: void
! 510: device_dump(void)
! 511: {
! 512: device_t dev;
! 513: struct devio *io;
! 514: list_t head, n;
! 515:
! 516: printk("Device dump:\n");
! 517: printk(" device open close read write ioctl "
! 518: "event name\n");
! 519: printk(" -------- -------- -------- -------- -------- -------- "
! 520: "-------- ------------\n");
! 521:
! 522: head = &device_list;
! 523: for (n = list_first(head); n != head; n = list_next(n)) {
! 524: dev = list_entry(n, struct device, link);
! 525: io = dev->devio;
! 526: printk(" %08x %08x %08x %08x %08x %08x %08x %s\n",
! 527: dev, io->open, io->close, io->read, io->write,
! 528: io->ioctl, io->event, dev->name);
! 529: }
! 530: }
! 531: #endif
! 532:
! 533: #ifndef DEBUG
! 534: static void
! 535: nosys(void)
! 536: {
! 537: }
! 538: #endif
! 539:
! 540: /*
! 541: * Check the capability of the current task.
! 542: */
! 543: static int
! 544: task__capable(cap_t cap)
! 545: {
! 546:
! 547: return task_capable(cap);
! 548: }
! 549:
! 550: /*
! 551: * Return boot information
! 552: */
! 553: static void
! 554: machine_bootinfo(struct boot_info **info)
! 555: {
! 556: ASSERT(info != NULL);
! 557:
! 558: *info = boot_info;
! 559: }
! 560:
! 561: static void
! 562: machine__reset(void)
! 563: {
! 564:
! 565: machine_reset();
! 566: }
! 567:
! 568: static void
! 569: machine__idle(void)
! 570: {
! 571:
! 572: machine_idle();
! 573: }
! 574:
! 575: /*
! 576: * Address transtion (physical -> virtual)
! 577: */
! 578: static void *
! 579: phys__to_virt(void *phys)
! 580: {
! 581:
! 582: return phys_to_virt(phys);
! 583: }
! 584:
! 585: /*
! 586: * Address transtion (virtual -> physical)
! 587: */
! 588: static void *
! 589: virt__to_phys(void *virt)
! 590: {
! 591:
! 592: return virt_to_phys(virt);
! 593: }
! 594:
! 595: /*
! 596: * Initialize device driver module.
! 597: */
! 598: void
! 599: device_init(void)
! 600: {
! 601: struct module *m;
! 602: void (*drv_entry)(const dkifn_t *);
! 603:
! 604: list_init(&device_list);
! 605:
! 606: m = &boot_info->driver;
! 607: if (m == NULL)
! 608: return;
! 609:
! 610: drv_entry = (void (*)(const dkifn_t *))m->entry;
! 611: if (drv_entry == NULL)
! 612: return;
! 613: /*
! 614: * Call all driver initialization functions.
! 615: */
! 616: drv_entry(driver_service);
! 617: }
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