drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* acpi_thermal_rel.c driver for exporting ACPI thermal relationship
   3  *
   4  * Copyright (c) 2014 Intel Corp
   5  */
   6
   7 /*
   8  * Two functionalities included:
   9  * 1. Export _TRT, _ART, via misc device interface to the userspace.
  10  * 2. Provide parsing result to kernel drivers
  11  *
  12  */
  13 #include <linux/init.h>
  14 #include <linux/export.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/io.h>
  19 #include <linux/acpi.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/miscdevice.h>
  22 #include <linux/fs.h>
  23 #include "acpi_thermal_rel.h"
  24
  25 static acpi_handle acpi_thermal_rel_handle;
  26 static DEFINE_SPINLOCK(acpi_thermal_rel_chrdev_lock);
  27 static int acpi_thermal_rel_chrdev_count;       /* #times opened */
  28 static int acpi_thermal_rel_chrdev_exclu;       /* already open exclusive? */
  29
  30 static int acpi_thermal_rel_open(struct inode *inode, struct file *file)
  31 {
  32         spin_lock(&acpi_thermal_rel_chrdev_lock);
  33         if (acpi_thermal_rel_chrdev_exclu ||
  34             (acpi_thermal_rel_chrdev_count && (file->f_flags & O_EXCL))) {
  35                 spin_unlock(&acpi_thermal_rel_chrdev_lock);
  36                 return -EBUSY;
  37         }
  38
  39         if (file->f_flags & O_EXCL)
  40                 acpi_thermal_rel_chrdev_exclu = 1;
  41         acpi_thermal_rel_chrdev_count++;
  42
  43         spin_unlock(&acpi_thermal_rel_chrdev_lock);
  44
  45         return nonseekable_open(inode, file);
  46 }
  47
  48 static int acpi_thermal_rel_release(struct inode *inode, struct file *file)
  49 {
  50         spin_lock(&acpi_thermal_rel_chrdev_lock);
  51         acpi_thermal_rel_chrdev_count--;
  52         acpi_thermal_rel_chrdev_exclu = 0;
  53         spin_unlock(&acpi_thermal_rel_chrdev_lock);
  54
  55         return 0;
  56 }
  57
  58 /**
  59  * acpi_parse_trt - Thermal Relationship Table _TRT for passive cooling
  60  *
  61  * @handle: ACPI handle of the device contains _TRT
  62  * @trt_count: the number of valid entries resulted from parsing _TRT
  63  * @trtp: pointer to pointer of array of _TRT entries in parsing result
  64  * @create_dev: whether to create platform devices for target and source
  65  *
  66  */
  67 int acpi_parse_trt(acpi_handle handle, int *trt_count, struct trt **trtp,
  68                 bool create_dev)
  69 {
  70         acpi_status status;
  71         int result = 0;
  72         int i;
  73         int nr_bad_entries = 0;
  74         struct trt *trts;
  75         struct acpi_device *adev;
  76         union acpi_object *p;
  77         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  78         struct acpi_buffer element = { 0, NULL };
  79         struct acpi_buffer trt_format = { sizeof("RRNNNNNN"), "RRNNNNNN" };
  80
  81         status = acpi_evaluate_object(handle, "_TRT", NULL, &buffer);
  82         if (ACPI_FAILURE(status))
  83                 return -ENODEV;
  84
  85         p = buffer.pointer;
  86         if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
  87                 pr_err("Invalid _TRT data\n");
  88                 result = -EFAULT;
  89                 goto end;
  90         }
  91
  92         *trt_count = p->package.count;
  93         trts = kcalloc(*trt_count, sizeof(struct trt), GFP_KERNEL);
  94         if (!trts) {
  95                 result = -ENOMEM;
  96                 goto end;
  97         }
  98
  99         for (i = 0; i < *trt_count; i++) {
 100                 struct trt *trt = &trts[i - nr_bad_entries];
 101
 102                 element.length = sizeof(struct trt);
 103                 element.pointer = trt;
 104
 105                 status = acpi_extract_package(&(p->package.elements[i]),
 106                                               &trt_format, &element);
 107                 if (ACPI_FAILURE(status)) {
 108                         nr_bad_entries++;
 109                         pr_warn("_TRT package %d is invalid, ignored\n", i);
 110                         continue;
 111                 }
 112                 if (!create_dev)
 113                         continue;
 114
 115                 result = acpi_bus_get_device(trt->source, &adev);
 116                 if (result)
 117                         pr_warn("Failed to get source ACPI device\n");
 118
 119                 result = acpi_bus_get_device(trt->target, &adev);
 120                 if (result)
 121                         pr_warn("Failed to get target ACPI device\n");
 122         }
 123
 124         result = 0;
 125
 126         *trtp = trts;
 127         /* don't count bad entries */
 128         *trt_count -= nr_bad_entries;
 129 end:
 130         kfree(buffer.pointer);
 131         return result;
 132 }
 133 EXPORT_SYMBOL(acpi_parse_trt);
 134
 135 /**
 136  * acpi_parse_art - Parse Active Relationship Table _ART
 137  *
 138  * @handle: ACPI handle of the device contains _ART
 139  * @art_count: the number of valid entries resulted from parsing _ART
 140  * @artp: pointer to pointer of array of art entries in parsing result
 141  * @create_dev: whether to create platform devices for target and source
 142  *
 143  */
 144 int acpi_parse_art(acpi_handle handle, int *art_count, struct art **artp,
 145                 bool create_dev)
 146 {
 147         acpi_status status;
 148         int result = 0;
 149         int i;
 150         int nr_bad_entries = 0;
 151         struct art *arts;
 152         struct acpi_device *adev;
 153         union acpi_object *p;
 154         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 155         struct acpi_buffer element = { 0, NULL };
 156         struct acpi_buffer art_format = {
 157                 sizeof("RRNNNNNNNNNNN"), "RRNNNNNNNNNNN" };
 158
 159         status = acpi_evaluate_object(handle, "_ART", NULL, &buffer);
 160         if (ACPI_FAILURE(status))
 161                 return -ENODEV;
 162
 163         p = buffer.pointer;
 164         if (!p || (p->type != ACPI_TYPE_PACKAGE)) {
 165                 pr_err("Invalid _ART data\n");
 166                 result = -EFAULT;
 167                 goto end;
 168         }
 169
 170         /* ignore p->package.elements[0], as this is _ART Revision field */
 171         *art_count = p->package.count - 1;
 172         arts = kcalloc(*art_count, sizeof(struct art), GFP_KERNEL);
 173         if (!arts) {
 174                 result = -ENOMEM;
 175                 goto end;
 176         }
 177
 178         for (i = 0; i < *art_count; i++) {
 179                 struct art *art = &arts[i - nr_bad_entries];
 180
 181                 element.length = sizeof(struct art);
 182                 element.pointer = art;
 183
 184                 status = acpi_extract_package(&(p->package.elements[i + 1]),
 185                                               &art_format, &element);
 186                 if (ACPI_FAILURE(status)) {
 187                         pr_warn("_ART package %d is invalid, ignored", i);
 188                         nr_bad_entries++;
 189                         continue;
 190                 }
 191                 if (!create_dev)
 192                         continue;
 193
 194                 if (art->source) {
 195                         result = acpi_bus_get_device(art->source, &adev);
 196                         if (result)
 197                                 pr_warn("Failed to get source ACPI device\n");
 198                 }
 199                 if (art->target) {
 200                         result = acpi_bus_get_device(art->target, &adev);
 201                         if (result)
 202                                 pr_warn("Failed to get target ACPI device\n");
 203                 }
 204         }
 205
 206         *artp = arts;
 207         /* don't count bad entries */
 208         *art_count -= nr_bad_entries;
 209 end:
 210         kfree(buffer.pointer);
 211         return result;
 212 }
 213 EXPORT_SYMBOL(acpi_parse_art);
 214
 215
 216 /* get device name from acpi handle */
 217 static void get_single_name(acpi_handle handle, char *name)
 218 {
 219         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
 220
 221         if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer)))
 222                 pr_warn("Failed to get device name from acpi handle\n");
 223         else {
 224                 memcpy(name, buffer.pointer, ACPI_NAMESEG_SIZE);
 225                 kfree(buffer.pointer);
 226         }
 227 }
 228
 229 static int fill_art(char __user *ubuf)
 230 {
 231         int i;
 232         int ret;
 233         int count;
 234         int art_len;
 235         struct art *arts = NULL;
 236         union art_object *art_user;
 237
 238         ret = acpi_parse_art(acpi_thermal_rel_handle, &count, &arts, false);
 239         if (ret)
 240                 goto free_art;
 241         art_len = count * sizeof(union art_object);
 242         art_user = kzalloc(art_len, GFP_KERNEL);
 243         if (!art_user) {
 244                 ret = -ENOMEM;
 245                 goto free_art;
 246         }
 247         /* now fill in user art data */
 248         for (i = 0; i < count; i++) {
 249                 /* userspace art needs device name instead of acpi reference */
 250                 get_single_name(arts[i].source, art_user[i].source_device);
 251                 get_single_name(arts[i].target, art_user[i].target_device);
 252                 /* copy the rest int data in addition to source and target */
 253                 memcpy(&art_user[i].weight, &arts[i].weight,
 254                         sizeof(u64) * (ACPI_NR_ART_ELEMENTS - 2));
 255         }
 256
 257         if (copy_to_user(ubuf, art_user, art_len))
 258                 ret = -EFAULT;
 259         kfree(art_user);
 260 free_art:
 261         kfree(arts);
 262         return ret;
 263 }
 264
 265 static int fill_trt(char __user *ubuf)
 266 {
 267         int i;
 268         int ret;
 269         int count;
 270         int trt_len;
 271         struct trt *trts = NULL;
 272         union trt_object *trt_user;
 273
 274         ret = acpi_parse_trt(acpi_thermal_rel_handle, &count, &trts, false);
 275         if (ret)
 276                 goto free_trt;
 277         trt_len = count * sizeof(union trt_object);
 278         trt_user = kzalloc(trt_len, GFP_KERNEL);
 279         if (!trt_user) {
 280                 ret = -ENOMEM;
 281                 goto free_trt;
 282         }
 283         /* now fill in user trt data */
 284         for (i = 0; i < count; i++) {
 285                 /* userspace trt needs device name instead of acpi reference */
 286                 get_single_name(trts[i].source, trt_user[i].source_device);
 287                 get_single_name(trts[i].target, trt_user[i].target_device);
 288                 trt_user[i].sample_period = trts[i].sample_period;
 289                 trt_user[i].influence = trts[i].influence;
 290         }
 291
 292         if (copy_to_user(ubuf, trt_user, trt_len))
 293                 ret = -EFAULT;
 294         kfree(trt_user);
 295 free_trt:
 296         kfree(trts);
 297         return ret;
 298 }
 299
 300 static long acpi_thermal_rel_ioctl(struct file *f, unsigned int cmd,
 301                                    unsigned long __arg)
 302 {
 303         int ret = 0;
 304         unsigned long length = 0;
 305         int count = 0;
 306         char __user *arg = (void __user *)__arg;
 307         struct trt *trts = NULL;
 308         struct art *arts = NULL;
 309
 310         switch (cmd) {
 311         case ACPI_THERMAL_GET_TRT_COUNT:
 312                 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
 313                                 &trts, false);
 314                 kfree(trts);
 315                 if (!ret)
 316                         return put_user(count, (unsigned long __user *)__arg);
 317                 return ret;
 318         case ACPI_THERMAL_GET_TRT_LEN:
 319                 ret = acpi_parse_trt(acpi_thermal_rel_handle, &count,
 320                                 &trts, false);
 321                 kfree(trts);
 322                 length = count * sizeof(union trt_object);
 323                 if (!ret)
 324                         return put_user(length, (unsigned long __user *)__arg);
 325                 return ret;
 326         case ACPI_THERMAL_GET_TRT:
 327                 return fill_trt(arg);
 328         case ACPI_THERMAL_GET_ART_COUNT:
 329                 ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
 330                                 &arts, false);
 331                 kfree(arts);
 332                 if (!ret)
 333                         return put_user(count, (unsigned long __user *)__arg);
 334                 return ret;
 335         case ACPI_THERMAL_GET_ART_LEN:
 336                 ret = acpi_parse_art(acpi_thermal_rel_handle, &count,
 337                                 &arts, false);
 338                 kfree(arts);
 339                 length = count * sizeof(union art_object);
 340                 if (!ret)
 341                         return put_user(length, (unsigned long __user *)__arg);
 342                 return ret;
 343
 344         case ACPI_THERMAL_GET_ART:
 345                 return fill_art(arg);
 346
 347         default:
 348                 return -ENOTTY;
 349         }
 350 }
 351
 352 static const struct file_operations acpi_thermal_rel_fops = {
 353         .owner          = THIS_MODULE,
 354         .open           = acpi_thermal_rel_open,
 355         .release        = acpi_thermal_rel_release,
 356         .unlocked_ioctl = acpi_thermal_rel_ioctl,
 357         .llseek         = no_llseek,
 358 };
 359
 360 static struct miscdevice acpi_thermal_rel_misc_device = {
 361         .minor  = MISC_DYNAMIC_MINOR,
 362         "acpi_thermal_rel",
 363         &acpi_thermal_rel_fops
 364 };
 365
 366 int acpi_thermal_rel_misc_device_add(acpi_handle handle)
 367 {
 368         acpi_thermal_rel_handle = handle;
 369
 370         return misc_register(&acpi_thermal_rel_misc_device);
 371 }
 372 EXPORT_SYMBOL(acpi_thermal_rel_misc_device_add);
 373
 374 int acpi_thermal_rel_misc_device_remove(acpi_handle handle)
 375 {
 376         misc_deregister(&acpi_thermal_rel_misc_device);
 377
 378         return 0;
 379 }
 380 EXPORT_SYMBOL(acpi_thermal_rel_misc_device_remove);
 381
 382 MODULE_AUTHOR("Zhang Rui <rui.zhang@intel.com>");
 383 MODULE_AUTHOR("Jacob Pan <jacob.jun.pan@intel.com");
 384 MODULE_DESCRIPTION("Intel acpi thermal rel misc dev driver");
 385 MODULE_LICENSE("GPL v2");