linux/drivers/s390/char/monwriter.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Character device driver for writing z/VM *MONITOR service records.
   4 *
   5 * Copyright IBM Corp. 2006, 2009
   6 *
   7 * Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
   8 */
   9
  10#define KMSG_COMPONENT "monwriter"
  11#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  12
  13#include <linux/module.h>
  14#include <linux/moduleparam.h>
  15#include <linux/init.h>
  16#include <linux/errno.h>
  17#include <linux/types.h>
  18#include <linux/kernel.h>
  19#include <linux/miscdevice.h>
  20#include <linux/ctype.h>
  21#include <linux/poll.h>
  22#include <linux/mutex.h>
  23#include <linux/platform_device.h>
  24#include <linux/slab.h>
  25#include <linux/uaccess.h>
  26#include <asm/ebcdic.h>
  27#include <asm/io.h>
  28#include <asm/appldata.h>
  29#include <asm/monwriter.h>
  30
  31#define MONWRITE_MAX_DATALEN    4010
  32
  33static int mon_max_bufs = 255;
  34static int mon_buf_count;
  35
  36struct mon_buf {
  37        struct list_head list;
  38        struct monwrite_hdr hdr;
  39        int diag_done;
  40        char *data;
  41};
  42
  43static LIST_HEAD(mon_priv_list);
  44
  45struct mon_private {
  46        struct list_head priv_list;
  47        struct list_head list;
  48        struct monwrite_hdr hdr;
  49        size_t hdr_to_read;
  50        size_t data_to_read;
  51        struct mon_buf *current_buf;
  52        struct mutex thread_mutex;
  53};
  54
  55/*
  56 * helper functions
  57 */
  58
  59static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn)
  60{
  61        struct appldata_parameter_list *parm_list;
  62        struct appldata_product_id *id;
  63        int rc;
  64
  65        id = kmalloc(sizeof(*id), GFP_KERNEL);
  66        parm_list = kmalloc(sizeof(*parm_list), GFP_KERNEL);
  67        rc = -ENOMEM;
  68        if (!id || !parm_list)
  69                goto out;
  70        memcpy(id->prod_nr, "LNXAPPL", 7);
  71        id->prod_fn = myhdr->applid;
  72        id->record_nr = myhdr->record_num;
  73        id->version_nr = myhdr->version;
  74        id->release_nr = myhdr->release;
  75        id->mod_lvl = myhdr->mod_level;
  76        rc = appldata_asm(parm_list, id, fcn,
  77                          (void *) buffer, myhdr->datalen);
  78        if (rc <= 0)
  79                goto out;
  80        pr_err("Writing monitor data failed with rc=%i\n", rc);
  81        rc = (rc == 5) ? -EPERM : -EINVAL;
  82out:
  83        kfree(id);
  84        kfree(parm_list);
  85        return rc;
  86}
  87
  88static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv,
  89                                         struct monwrite_hdr *monhdr)
  90{
  91        struct mon_buf *entry, *next;
  92
  93        list_for_each_entry_safe(entry, next, &monpriv->list, list)
  94                if ((entry->hdr.mon_function == monhdr->mon_function ||
  95                     monhdr->mon_function == MONWRITE_STOP_INTERVAL) &&
  96                    entry->hdr.applid == monhdr->applid &&
  97                    entry->hdr.record_num == monhdr->record_num &&
  98                    entry->hdr.version == monhdr->version &&
  99                    entry->hdr.release == monhdr->release &&
 100                    entry->hdr.mod_level == monhdr->mod_level)
 101                        return entry;
 102
 103        return NULL;
 104}
 105
 106static int monwrite_new_hdr(struct mon_private *monpriv)
 107{
 108        struct monwrite_hdr *monhdr = &monpriv->hdr;
 109        struct mon_buf *monbuf;
 110        int rc = 0;
 111
 112        if (monhdr->datalen > MONWRITE_MAX_DATALEN ||
 113            monhdr->mon_function > MONWRITE_START_CONFIG ||
 114            monhdr->hdrlen != sizeof(struct monwrite_hdr))
 115                return -EINVAL;
 116        monbuf = NULL;
 117        if (monhdr->mon_function != MONWRITE_GEN_EVENT)
 118                monbuf = monwrite_find_hdr(monpriv, monhdr);
 119        if (monbuf) {
 120                if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
 121                        monhdr->datalen = monbuf->hdr.datalen;
 122                        rc = monwrite_diag(monhdr, monbuf->data,
 123                                           APPLDATA_STOP_REC);
 124                        list_del(&monbuf->list);
 125                        mon_buf_count--;
 126                        kfree(monbuf->data);
 127                        kfree(monbuf);
 128                        monbuf = NULL;
 129                }
 130        } else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) {
 131                if (mon_buf_count >= mon_max_bufs)
 132                        return -ENOSPC;
 133                monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
 134                if (!monbuf)
 135                        return -ENOMEM;
 136                monbuf->data = kzalloc(monhdr->datalen,
 137                                       GFP_KERNEL | GFP_DMA);
 138                if (!monbuf->data) {
 139                        kfree(monbuf);
 140                        return -ENOMEM;
 141                }
 142                monbuf->hdr = *monhdr;
 143                list_add_tail(&monbuf->list, &monpriv->list);
 144                if (monhdr->mon_function != MONWRITE_GEN_EVENT)
 145                        mon_buf_count++;
 146        }
 147        monpriv->current_buf = monbuf;
 148        return rc;
 149}
 150
 151static int monwrite_new_data(struct mon_private *monpriv)
 152{
 153        struct monwrite_hdr *monhdr = &monpriv->hdr;
 154        struct mon_buf *monbuf = monpriv->current_buf;
 155        int rc = 0;
 156
 157        switch (monhdr->mon_function) {
 158        case MONWRITE_START_INTERVAL:
 159                if (!monbuf->diag_done) {
 160                        rc = monwrite_diag(monhdr, monbuf->data,
 161                                           APPLDATA_START_INTERVAL_REC);
 162                        monbuf->diag_done = 1;
 163                }
 164                break;
 165        case MONWRITE_START_CONFIG:
 166                if (!monbuf->diag_done) {
 167                        rc = monwrite_diag(monhdr, monbuf->data,
 168                                           APPLDATA_START_CONFIG_REC);
 169                        monbuf->diag_done = 1;
 170                }
 171                break;
 172        case MONWRITE_GEN_EVENT:
 173                rc = monwrite_diag(monhdr, monbuf->data,
 174                                   APPLDATA_GEN_EVENT_REC);
 175                list_del(&monpriv->current_buf->list);
 176                kfree(monpriv->current_buf->data);
 177                kfree(monpriv->current_buf);
 178                monpriv->current_buf = NULL;
 179                break;
 180        default:
 181                /* monhdr->mon_function is checked in monwrite_new_hdr */
 182                BUG();
 183        }
 184        return rc;
 185}
 186
 187/*
 188 * file operations
 189 */
 190
 191static int monwrite_open(struct inode *inode, struct file *filp)
 192{
 193        struct mon_private *monpriv;
 194
 195        monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
 196        if (!monpriv)
 197                return -ENOMEM;
 198        INIT_LIST_HEAD(&monpriv->list);
 199        monpriv->hdr_to_read = sizeof(monpriv->hdr);
 200        mutex_init(&monpriv->thread_mutex);
 201        filp->private_data = monpriv;
 202        list_add_tail(&monpriv->priv_list, &mon_priv_list);
 203        return nonseekable_open(inode, filp);
 204}
 205
 206static int monwrite_close(struct inode *inode, struct file *filp)
 207{
 208        struct mon_private *monpriv = filp->private_data;
 209        struct mon_buf *entry, *next;
 210
 211        list_for_each_entry_safe(entry, next, &monpriv->list, list) {
 212                if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
 213                        monwrite_diag(&entry->hdr, entry->data,
 214                                      APPLDATA_STOP_REC);
 215                mon_buf_count--;
 216                list_del(&entry->list);
 217                kfree(entry->data);
 218                kfree(entry);
 219        }
 220        list_del(&monpriv->priv_list);
 221        kfree(monpriv);
 222        return 0;
 223}
 224
 225static ssize_t monwrite_write(struct file *filp, const char __user *data,
 226                              size_t count, loff_t *ppos)
 227{
 228        struct mon_private *monpriv = filp->private_data;
 229        size_t len, written;
 230        void *to;
 231        int rc;
 232
 233        mutex_lock(&monpriv->thread_mutex);
 234        for (written = 0; written < count; ) {
 235                if (monpriv->hdr_to_read) {
 236                        len = min(count - written, monpriv->hdr_to_read);
 237                        to = (char *) &monpriv->hdr +
 238                                sizeof(monpriv->hdr) - monpriv->hdr_to_read;
 239                        if (copy_from_user(to, data + written, len)) {
 240                                rc = -EFAULT;
 241                                goto out_error;
 242                        }
 243                        monpriv->hdr_to_read -= len;
 244                        written += len;
 245                        if (monpriv->hdr_to_read > 0)
 246                                continue;
 247                        rc = monwrite_new_hdr(monpriv);
 248                        if (rc)
 249                                goto out_error;
 250                        monpriv->data_to_read = monpriv->current_buf ?
 251                                monpriv->current_buf->hdr.datalen : 0;
 252                }
 253
 254                if (monpriv->data_to_read) {
 255                        len = min(count - written, monpriv->data_to_read);
 256                        to = monpriv->current_buf->data +
 257                                monpriv->hdr.datalen - monpriv->data_to_read;
 258                        if (copy_from_user(to, data + written, len)) {
 259                                rc = -EFAULT;
 260                                goto out_error;
 261                        }
 262                        monpriv->data_to_read -= len;
 263                        written += len;
 264                        if (monpriv->data_to_read > 0)
 265                                continue;
 266                        rc = monwrite_new_data(monpriv);
 267                        if (rc)
 268                                goto out_error;
 269                }
 270                monpriv->hdr_to_read = sizeof(monpriv->hdr);
 271        }
 272        mutex_unlock(&monpriv->thread_mutex);
 273        return written;
 274
 275out_error:
 276        monpriv->data_to_read = 0;
 277        monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
 278        mutex_unlock(&monpriv->thread_mutex);
 279        return rc;
 280}
 281
 282static const struct file_operations monwrite_fops = {
 283        .owner   = THIS_MODULE,
 284        .open    = &monwrite_open,
 285        .release = &monwrite_close,
 286        .write   = &monwrite_write,
 287        .llseek  = noop_llseek,
 288};
 289
 290static struct miscdevice mon_dev = {
 291        .name   = "monwriter",
 292        .fops   = &monwrite_fops,
 293        .minor  = MISC_DYNAMIC_MINOR,
 294};
 295
 296/*
 297 * suspend/resume
 298 */
 299
 300static int monwriter_freeze(struct device *dev)
 301{
 302        struct mon_private *monpriv;
 303        struct mon_buf *monbuf;
 304
 305        list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
 306                list_for_each_entry(monbuf, &monpriv->list, list) {
 307                        if (monbuf->hdr.mon_function != MONWRITE_GEN_EVENT)
 308                                monwrite_diag(&monbuf->hdr, monbuf->data,
 309                                              APPLDATA_STOP_REC);
 310                }
 311        }
 312        return 0;
 313}
 314
 315static int monwriter_restore(struct device *dev)
 316{
 317        struct mon_private *monpriv;
 318        struct mon_buf *monbuf;
 319
 320        list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
 321                list_for_each_entry(monbuf, &monpriv->list, list) {
 322                        if (monbuf->hdr.mon_function == MONWRITE_START_INTERVAL)
 323                                monwrite_diag(&monbuf->hdr, monbuf->data,
 324                                              APPLDATA_START_INTERVAL_REC);
 325                        if (monbuf->hdr.mon_function == MONWRITE_START_CONFIG)
 326                                monwrite_diag(&monbuf->hdr, monbuf->data,
 327                                              APPLDATA_START_CONFIG_REC);
 328                }
 329        }
 330        return 0;
 331}
 332
 333static int monwriter_thaw(struct device *dev)
 334{
 335        return monwriter_restore(dev);
 336}
 337
 338static const struct dev_pm_ops monwriter_pm_ops = {
 339        .freeze         = monwriter_freeze,
 340        .thaw           = monwriter_thaw,
 341        .restore        = monwriter_restore,
 342};
 343
 344static struct platform_driver monwriter_pdrv = {
 345        .driver = {
 346                .name   = "monwriter",
 347                .pm     = &monwriter_pm_ops,
 348        },
 349};
 350
 351static struct platform_device *monwriter_pdev;
 352
 353/*
 354 * module init/exit
 355 */
 356
 357static int __init mon_init(void)
 358{
 359        int rc;
 360
 361        if (!MACHINE_IS_VM)
 362                return -ENODEV;
 363
 364        rc = platform_driver_register(&monwriter_pdrv);
 365        if (rc)
 366                return rc;
 367
 368        monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
 369                                                        0);
 370        if (IS_ERR(monwriter_pdev)) {
 371                rc = PTR_ERR(monwriter_pdev);
 372                goto out_driver;
 373        }
 374
 375        /*
 376         * misc_register() has to be the last action in module_init(), because
 377         * file operations will be available right after this.
 378         */
 379        rc = misc_register(&mon_dev);
 380        if (rc)
 381                goto out_device;
 382        return 0;
 383
 384out_device:
 385        platform_device_unregister(monwriter_pdev);
 386out_driver:
 387        platform_driver_unregister(&monwriter_pdrv);
 388        return rc;
 389}
 390
 391static void __exit mon_exit(void)
 392{
 393        misc_deregister(&mon_dev);
 394        platform_device_unregister(monwriter_pdev);
 395        platform_driver_unregister(&monwriter_pdrv);
 396}
 397
 398module_init(mon_init);
 399module_exit(mon_exit);
 400
 401module_param_named(max_bufs, mon_max_bufs, int, 0644);
 402MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
 403                 "that can be active at one time");
 404
 405MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
 406MODULE_DESCRIPTION("Character device driver for writing z/VM "
 407                   "APPLDATA monitor records.");
 408MODULE_LICENSE("GPL");
 409