drivers/hwmon/i5k_amb.c

   1 /*
   2  * A hwmon driver for the Intel 5000 series chipset FB-DIMM AMB
   3  * temperature sensors
   4  * Copyright (C) 2007 IBM
   5  *
   6  * Author: Darrick J. Wong <djwong@us.ibm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/hwmon.h>
  26 #include <linux/hwmon-sysfs.h>
  27 #include <linux/err.h>
  28 #include <linux/mutex.h>
  29 #include <linux/delay.h>
  30 #include <linux/log2.h>
  31 #include <linux/pci.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/slab.h>
  34
  35 #define DRVNAME "i5k_amb"
  36
  37 #define I5K_REG_AMB_BASE_ADDR           0x48
  38 #define I5K_REG_AMB_LEN_ADDR            0x50
  39 #define I5K_REG_CHAN0_PRESENCE_ADDR     0x64
  40 #define I5K_REG_CHAN1_PRESENCE_ADDR     0x66
  41
  42 #define AMB_REG_TEMP_MIN_ADDR           0x80
  43 #define AMB_REG_TEMP_MID_ADDR           0x81
  44 #define AMB_REG_TEMP_MAX_ADDR           0x82
  45 #define AMB_REG_TEMP_STATUS_ADDR        0x84
  46 #define AMB_REG_TEMP_ADDR               0x85
  47
  48 #define AMB_CONFIG_SIZE                 2048
  49 #define AMB_FUNC_3_OFFSET               768
  50
  51 static unsigned long amb_reg_temp_status(unsigned int amb)
  52 {
  53         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_STATUS_ADDR +
  54                AMB_CONFIG_SIZE * amb;
  55 }
  56
  57 static unsigned long amb_reg_temp_min(unsigned int amb)
  58 {
  59         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MIN_ADDR +
  60                AMB_CONFIG_SIZE * amb;
  61 }
  62
  63 static unsigned long amb_reg_temp_mid(unsigned int amb)
  64 {
  65         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MID_ADDR +
  66                AMB_CONFIG_SIZE * amb;
  67 }
  68
  69 static unsigned long amb_reg_temp_max(unsigned int amb)
  70 {
  71         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MAX_ADDR +
  72                AMB_CONFIG_SIZE * amb;
  73 }
  74
  75 static unsigned long amb_reg_temp(unsigned int amb)
  76 {
  77         return AMB_FUNC_3_OFFSET + AMB_REG_TEMP_ADDR +
  78                AMB_CONFIG_SIZE * amb;
  79 }
  80
  81 #define MAX_MEM_CHANNELS                4
  82 #define MAX_AMBS_PER_CHANNEL            16
  83 #define MAX_AMBS                        (MAX_MEM_CHANNELS * \
  84                                          MAX_AMBS_PER_CHANNEL)
  85 #define CHANNEL_SHIFT                   4
  86 #define DIMM_MASK                       0xF
  87 /*
  88  * Ugly hack: For some reason the highest bit is set if there
  89  * are _any_ DIMMs in the channel.  Attempting to read from
  90  * this "high-order" AMB results in a memory bus error, so
  91  * for now we'll just ignore that top bit, even though that
  92  * might prevent us from seeing the 16th DIMM in the channel.
  93  */
  94 #define REAL_MAX_AMBS_PER_CHANNEL       15
  95 #define KNOBS_PER_AMB                   6
  96
  97 static unsigned long amb_num_from_reg(unsigned int byte_num, unsigned int bit)
  98 {
  99         return byte_num * MAX_AMBS_PER_CHANNEL + bit;
 100 }
 101
 102 #define AMB_SYSFS_NAME_LEN              16
 103 struct i5k_device_attribute {
 104         struct sensor_device_attribute s_attr;
 105         char name[AMB_SYSFS_NAME_LEN];
 106 };
 107
 108 struct i5k_amb_data {
 109         struct device *hwmon_dev;
 110
 111         unsigned long amb_base;
 112         unsigned long amb_len;
 113         u16 amb_present[MAX_MEM_CHANNELS];
 114         void __iomem *amb_mmio;
 115         struct i5k_device_attribute *attrs;
 116         unsigned int num_attrs;
 117         unsigned long chipset_id;
 118 };
 119
 120 static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
 121                          char *buf)
 122 {
 123         return sprintf(buf, "%s\n", DRVNAME);
 124 }
 125
 126
 127 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 128
 129 static struct platform_device *amb_pdev;
 130
 131 static u8 amb_read_byte(struct i5k_amb_data *data, unsigned long offset)
 132 {
 133         return ioread8(data->amb_mmio + offset);
 134 }
 135
 136 static void amb_write_byte(struct i5k_amb_data *data, unsigned long offset,
 137                            u8 val)
 138 {
 139         iowrite8(val, data->amb_mmio + offset);
 140 }
 141
 142 static ssize_t show_amb_alarm(struct device *dev,
 143                              struct device_attribute *devattr,
 144                              char *buf)
 145 {
 146         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 147         struct i5k_amb_data *data = dev_get_drvdata(dev);
 148
 149         if (!(amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x20) &&
 150              (amb_read_byte(data, amb_reg_temp_status(attr->index)) & 0x8))
 151                 return sprintf(buf, "1\n");
 152         else
 153                 return sprintf(buf, "0\n");
 154 }
 155
 156 static ssize_t store_amb_min(struct device *dev,
 157                              struct device_attribute *devattr,
 158                              const char *buf,
 159                              size_t count)
 160 {
 161         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 162         struct i5k_amb_data *data = dev_get_drvdata(dev);
 163         unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
 164
 165         if (temp > 255)
 166                 temp = 255;
 167
 168         amb_write_byte(data, amb_reg_temp_min(attr->index), temp);
 169         return count;
 170 }
 171
 172 static ssize_t store_amb_mid(struct device *dev,
 173                              struct device_attribute *devattr,
 174                              const char *buf,
 175                              size_t count)
 176 {
 177         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 178         struct i5k_amb_data *data = dev_get_drvdata(dev);
 179         unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
 180
 181         if (temp > 255)
 182                 temp = 255;
 183
 184         amb_write_byte(data, amb_reg_temp_mid(attr->index), temp);
 185         return count;
 186 }
 187
 188 static ssize_t store_amb_max(struct device *dev,
 189                              struct device_attribute *devattr,
 190                              const char *buf,
 191                              size_t count)
 192 {
 193         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 194         struct i5k_amb_data *data = dev_get_drvdata(dev);
 195         unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
 196
 197         if (temp > 255)
 198                 temp = 255;
 199
 200         amb_write_byte(data, amb_reg_temp_max(attr->index), temp);
 201         return count;
 202 }
 203
 204 static ssize_t show_amb_min(struct device *dev,
 205                              struct device_attribute *devattr,
 206                              char *buf)
 207 {
 208         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 209         struct i5k_amb_data *data = dev_get_drvdata(dev);
 210         return sprintf(buf, "%d\n",
 211                 500 * amb_read_byte(data, amb_reg_temp_min(attr->index)));
 212 }
 213
 214 static ssize_t show_amb_mid(struct device *dev,
 215                              struct device_attribute *devattr,
 216                              char *buf)
 217 {
 218         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 219         struct i5k_amb_data *data = dev_get_drvdata(dev);
 220         return sprintf(buf, "%d\n",
 221                 500 * amb_read_byte(data, amb_reg_temp_mid(attr->index)));
 222 }
 223
 224 static ssize_t show_amb_max(struct device *dev,
 225                              struct device_attribute *devattr,
 226                              char *buf)
 227 {
 228         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 229         struct i5k_amb_data *data = dev_get_drvdata(dev);
 230         return sprintf(buf, "%d\n",
 231                 500 * amb_read_byte(data, amb_reg_temp_max(attr->index)));
 232 }
 233
 234 static ssize_t show_amb_temp(struct device *dev,
 235                              struct device_attribute *devattr,
 236                              char *buf)
 237 {
 238         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 239         struct i5k_amb_data *data = dev_get_drvdata(dev);
 240         return sprintf(buf, "%d\n",
 241                 500 * amb_read_byte(data, amb_reg_temp(attr->index)));
 242 }
 243
 244 static ssize_t show_label(struct device *dev,
 245                           struct device_attribute *devattr,
 246                           char *buf)
 247 {
 248         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 249
 250         return sprintf(buf, "Ch. %d DIMM %d\n", attr->index >> CHANNEL_SHIFT,
 251                        attr->index & DIMM_MASK);
 252 }
 253
 254 static int __devinit i5k_amb_hwmon_init(struct platform_device *pdev)
 255 {
 256         int i, j, k, d = 0;
 257         u16 c;
 258         int res = 0;
 259         int num_ambs = 0;
 260         struct i5k_amb_data *data = platform_get_drvdata(pdev);
 261
 262         /* Count the number of AMBs found */
 263         /* ignore the high-order bit, see "Ugly hack" comment above */
 264         for (i = 0; i < MAX_MEM_CHANNELS; i++)
 265                 num_ambs += hweight16(data->amb_present[i] & 0x7fff);
 266
 267         /* Set up sysfs stuff */
 268         data->attrs = kzalloc(sizeof(*data->attrs) * num_ambs * KNOBS_PER_AMB,
 269                                 GFP_KERNEL);
 270         if (!data->attrs)
 271                 return -ENOMEM;
 272         data->num_attrs = 0;
 273
 274         for (i = 0; i < MAX_MEM_CHANNELS; i++) {
 275                 c = data->amb_present[i];
 276                 for (j = 0; j < REAL_MAX_AMBS_PER_CHANNEL; j++, c >>= 1) {
 277                         struct i5k_device_attribute *iattr;
 278
 279                         k = amb_num_from_reg(i, j);
 280                         if (!(c & 0x1))
 281                                 continue;
 282                         d++;
 283
 284                         /* sysfs label */
 285                         iattr = data->attrs + data->num_attrs;
 286                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 287                                  "temp%d_label", d);
 288                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 289                         iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
 290                         iattr->s_attr.dev_attr.show = show_label;
 291                         iattr->s_attr.index = k;
 292                         res = device_create_file(&pdev->dev,
 293                                                  &iattr->s_attr.dev_attr);
 294                         if (res)
 295                                 goto exit_remove;
 296                         data->num_attrs++;
 297
 298                         /* Temperature sysfs knob */
 299                         iattr = data->attrs + data->num_attrs;
 300                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 301                                  "temp%d_input", d);
 302                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 303                         iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
 304                         iattr->s_attr.dev_attr.show = show_amb_temp;
 305                         iattr->s_attr.index = k;
 306                         res = device_create_file(&pdev->dev,
 307                                                  &iattr->s_attr.dev_attr);
 308                         if (res)
 309                                 goto exit_remove;
 310                         data->num_attrs++;
 311
 312                         /* Temperature min sysfs knob */
 313                         iattr = data->attrs + data->num_attrs;
 314                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 315                                  "temp%d_min", d);
 316                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 317                         iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
 318                         iattr->s_attr.dev_attr.show = show_amb_min;
 319                         iattr->s_attr.dev_attr.store = store_amb_min;
 320                         iattr->s_attr.index = k;
 321                         res = device_create_file(&pdev->dev,
 322                                                  &iattr->s_attr.dev_attr);
 323                         if (res)
 324                                 goto exit_remove;
 325                         data->num_attrs++;
 326
 327                         /* Temperature mid sysfs knob */
 328                         iattr = data->attrs + data->num_attrs;
 329                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 330                                  "temp%d_mid", d);
 331                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 332                         iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
 333                         iattr->s_attr.dev_attr.show = show_amb_mid;
 334                         iattr->s_attr.dev_attr.store = store_amb_mid;
 335                         iattr->s_attr.index = k;
 336                         res = device_create_file(&pdev->dev,
 337                                                  &iattr->s_attr.dev_attr);
 338                         if (res)
 339                                 goto exit_remove;
 340                         data->num_attrs++;
 341
 342                         /* Temperature max sysfs knob */
 343                         iattr = data->attrs + data->num_attrs;
 344                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 345                                  "temp%d_max", d);
 346                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 347                         iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
 348                         iattr->s_attr.dev_attr.show = show_amb_max;
 349                         iattr->s_attr.dev_attr.store = store_amb_max;
 350                         iattr->s_attr.index = k;
 351                         res = device_create_file(&pdev->dev,
 352                                                  &iattr->s_attr.dev_attr);
 353                         if (res)
 354                                 goto exit_remove;
 355                         data->num_attrs++;
 356
 357                         /* Temperature alarm sysfs knob */
 358                         iattr = data->attrs + data->num_attrs;
 359                         snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
 360                                  "temp%d_alarm", d);
 361                         iattr->s_attr.dev_attr.attr.name = iattr->name;
 362                         iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
 363                         iattr->s_attr.dev_attr.show = show_amb_alarm;
 364                         iattr->s_attr.index = k;
 365                         res = device_create_file(&pdev->dev,
 366                                                  &iattr->s_attr.dev_attr);
 367                         if (res)
 368                                 goto exit_remove;
 369                         data->num_attrs++;
 370                 }
 371         }
 372
 373         res = device_create_file(&pdev->dev, &dev_attr_name);
 374         if (res)
 375                 goto exit_remove;
 376
 377         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 378         if (IS_ERR(data->hwmon_dev)) {
 379                 res = PTR_ERR(data->hwmon_dev);
 380                 goto exit_remove;
 381         }
 382
 383         return res;
 384
 385 exit_remove:
 386         device_remove_file(&pdev->dev, &dev_attr_name);
 387         for (i = 0; i < data->num_attrs; i++)
 388                 device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
 389         kfree(data->attrs);
 390
 391         return res;
 392 }
 393
 394 static int __devinit i5k_amb_add(void)
 395 {
 396         int res = -ENODEV;
 397
 398         /* only ever going to be one of these */
 399         amb_pdev = platform_device_alloc(DRVNAME, 0);
 400         if (!amb_pdev)
 401                 return -ENOMEM;
 402
 403         res = platform_device_add(amb_pdev);
 404         if (res)
 405                 goto err;
 406         return 0;
 407
 408 err:
 409         platform_device_put(amb_pdev);
 410         return res;
 411 }
 412
 413 static int __devinit i5k_find_amb_registers(struct i5k_amb_data *data,
 414                                             unsigned long devid)
 415 {
 416         struct pci_dev *pcidev;
 417         u32 val32;
 418         int res = -ENODEV;
 419
 420         /* Find AMB register memory space */
 421         pcidev = pci_get_device(PCI_VENDOR_ID_INTEL,
 422                                 devid,
 423                                 NULL);
 424         if (!pcidev)
 425                 return -ENODEV;
 426
 427         if (pci_read_config_dword(pcidev, I5K_REG_AMB_BASE_ADDR, &val32))
 428                 goto out;
 429         data->amb_base = val32;
 430
 431         if (pci_read_config_dword(pcidev, I5K_REG_AMB_LEN_ADDR, &val32))
 432                 goto out;
 433         data->amb_len = val32;
 434
 435         /* Is it big enough? */
 436         if (data->amb_len < AMB_CONFIG_SIZE * MAX_AMBS) {
 437                 dev_err(&pcidev->dev, "AMB region too small!\n");
 438                 goto out;
 439         }
 440
 441         data->chipset_id = devid;
 442
 443         res = 0;
 444 out:
 445         pci_dev_put(pcidev);
 446         return res;
 447 }
 448
 449 static int __devinit i5k_channel_probe(u16 *amb_present, unsigned long dev_id)
 450 {
 451         struct pci_dev *pcidev;
 452         u16 val16;
 453         int res = -ENODEV;
 454
 455         /* Copy the DIMM presence map for these two channels */
 456         pcidev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id, NULL);
 457         if (!pcidev)
 458                 return -ENODEV;
 459
 460         if (pci_read_config_word(pcidev, I5K_REG_CHAN0_PRESENCE_ADDR, &val16))
 461                 goto out;
 462         amb_present[0] = val16;
 463
 464         if (pci_read_config_word(pcidev, I5K_REG_CHAN1_PRESENCE_ADDR, &val16))
 465                 goto out;
 466         amb_present[1] = val16;
 467
 468         res = 0;
 469
 470 out:
 471         pci_dev_put(pcidev);
 472         return res;
 473 }
 474
 475 static unsigned long i5k_channel_pci_id(struct i5k_amb_data *data,
 476                                         unsigned long channel)
 477 {
 478         switch (data->chipset_id) {
 479         case PCI_DEVICE_ID_INTEL_5000_ERR:
 480                 return PCI_DEVICE_ID_INTEL_5000_FBD0 + channel;
 481         case PCI_DEVICE_ID_INTEL_5400_ERR:
 482                 return PCI_DEVICE_ID_INTEL_5400_FBD0 + channel;
 483         default:
 484                 BUG();
 485         }
 486 }
 487
 488 static unsigned long chipset_ids[] = {
 489         PCI_DEVICE_ID_INTEL_5000_ERR,
 490         PCI_DEVICE_ID_INTEL_5400_ERR,
 491         0
 492 };
 493
 494 static struct pci_device_id i5k_amb_ids[] __devinitdata = {
 495         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5000_ERR) },
 496         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5400_ERR) },
 497         { 0, }
 498 };
 499 MODULE_DEVICE_TABLE(pci, i5k_amb_ids);
 500
 501 static int __devinit i5k_amb_probe(struct platform_device *pdev)
 502 {
 503         struct i5k_amb_data *data;
 504         struct resource *reso;
 505         int i;
 506         int res = -ENODEV;
 507
 508         data = kzalloc(sizeof(*data), GFP_KERNEL);
 509         if (!data)
 510                 return -ENOMEM;
 511
 512         /* Figure out where the AMB registers live */
 513         i = 0;
 514         do {
 515                 res = i5k_find_amb_registers(data, chipset_ids[i]);
 516                 i++;
 517         } while (res && chipset_ids[i]);
 518
 519         if (res)
 520                 goto err;
 521
 522         /* Copy the DIMM presence map for the first two channels */
 523         res = i5k_channel_probe(&data->amb_present[0],
 524                                 i5k_channel_pci_id(data, 0));
 525         if (res)
 526                 goto err;
 527
 528         /* Copy the DIMM presence map for the optional second two channels */
 529         i5k_channel_probe(&data->amb_present[2],
 530                           i5k_channel_pci_id(data, 1));
 531
 532         /* Set up resource regions */
 533         reso = request_mem_region(data->amb_base, data->amb_len, DRVNAME);
 534         if (!reso) {
 535                 res = -EBUSY;
 536                 goto err;
 537         }
 538
 539         data->amb_mmio = ioremap_nocache(data->amb_base, data->amb_len);
 540         if (!data->amb_mmio) {
 541                 res = -EBUSY;
 542                 goto err_map_failed;
 543         }
 544
 545         platform_set_drvdata(pdev, data);
 546
 547         res = i5k_amb_hwmon_init(pdev);
 548         if (res)
 549                 goto err_init_failed;
 550
 551         return res;
 552
 553 err_init_failed:
 554         iounmap(data->amb_mmio);
 555         platform_set_drvdata(pdev, NULL);
 556 err_map_failed:
 557         release_mem_region(data->amb_base, data->amb_len);
 558 err:
 559         kfree(data);
 560         return res;
 561 }
 562
 563 static int __devexit i5k_amb_remove(struct platform_device *pdev)
 564 {
 565         int i;
 566         struct i5k_amb_data *data = platform_get_drvdata(pdev);
 567
 568         hwmon_device_unregister(data->hwmon_dev);
 569         device_remove_file(&pdev->dev, &dev_attr_name);
 570         for (i = 0; i < data->num_attrs; i++)
 571                 device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
 572         kfree(data->attrs);
 573         iounmap(data->amb_mmio);
 574         release_mem_region(data->amb_base, data->amb_len);
 575         platform_set_drvdata(pdev, NULL);
 576         kfree(data);
 577         return 0;
 578 }
 579
 580 static struct platform_driver i5k_amb_driver = {
 581         .driver = {
 582                 .owner = THIS_MODULE,
 583                 .name = DRVNAME,
 584         },
 585         .probe = i5k_amb_probe,
 586         .remove = __devexit_p(i5k_amb_remove),
 587 };
 588
 589 static int __init i5k_amb_init(void)
 590 {
 591         int res;
 592
 593         res = platform_driver_register(&i5k_amb_driver);
 594         if (res)
 595                 return res;
 596
 597         res = i5k_amb_add();
 598         if (res)
 599                 platform_driver_unregister(&i5k_amb_driver);
 600
 601         return res;
 602 }
 603
 604 static void __exit i5k_amb_exit(void)
 605 {
 606         platform_device_unregister(amb_pdev);
 607         platform_driver_unregister(&i5k_amb_driver);
 608 }
 609
 610 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
 611 MODULE_DESCRIPTION("Intel 5000 chipset FB-DIMM AMB temperature sensor");
 612 MODULE_LICENSE("GPL");
 613
 614 module_init(i5k_amb_init);
 615 module_exit(i5k_amb_exit);