1 /* 2 * drivers/s390/char/monwriter.c 3 * 4 * Character device driver for writing z/VM *MONITOR service records. 5 * 6 * Copyright (C) IBM Corp. 2006 7 * 8 * Author(s): Melissa Howland <Melissa.Howland@us.ibm.com> 9 */ 10 11 #include <linux/module.h> 12 #include <linux/moduleparam.h> 13 #include <linux/init.h> 14 #include <linux/errno.h> 15 #include <linux/smp_lock.h> 16 #include <linux/types.h> 17 #include <linux/kernel.h> 18 #include <linux/miscdevice.h> 19 #include <linux/ctype.h> 20 #include <linux/poll.h> 21 #include <linux/mutex.h> 22 #include <asm/uaccess.h> 23 #include <asm/ebcdic.h> 24 #include <asm/io.h> 25 #include <asm/appldata.h> 26 #include <asm/monwriter.h> 27 28 #define MONWRITE_MAX_DATALEN 4010 29 30 static int mon_max_bufs = 255; 31 static int mon_buf_count; 32 33 struct mon_buf { 34 struct list_head list; 35 struct monwrite_hdr hdr; 36 int diag_done; 37 char *data; 38 }; 39 40 struct mon_private { 41 struct list_head list; 42 struct monwrite_hdr hdr; 43 size_t hdr_to_read; 44 size_t data_to_read; 45 struct mon_buf *current_buf; 46 struct mutex thread_mutex; 47 }; 48 49 /* 50 * helper functions 51 */ 52 53 static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn) 54 { 55 struct appldata_product_id id; 56 int rc; 57 58 strcpy(id.prod_nr, "LNXAPPL"); 59 id.prod_fn = myhdr->applid; 60 id.record_nr = myhdr->record_num; 61 id.version_nr = myhdr->version; 62 id.release_nr = myhdr->release; 63 id.mod_lvl = myhdr->mod_level; 64 rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen); 65 if (rc <= 0) 66 return rc; 67 if (rc == 5) 68 return -EPERM; 69 printk("DIAG X'DC' error with return code: %i\n", rc); 70 return -EINVAL; 71 } 72 73 static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv, 74 struct monwrite_hdr *monhdr) 75 { 76 struct mon_buf *entry, *next; 77 78 list_for_each_entry_safe(entry, next, &monpriv->list, list) 79 if ((entry->hdr.mon_function == monhdr->mon_function || 80 monhdr->mon_function == MONWRITE_STOP_INTERVAL) && 81 entry->hdr.applid == monhdr->applid && 82 entry->hdr.record_num == monhdr->record_num && 83 entry->hdr.version == monhdr->version && 84 entry->hdr.release == monhdr->release && 85 entry->hdr.mod_level == monhdr->mod_level) 86 return entry; 87 88 return NULL; 89 } 90 91 static int monwrite_new_hdr(struct mon_private *monpriv) 92 { 93 struct monwrite_hdr *monhdr = &monpriv->hdr; 94 struct mon_buf *monbuf; 95 int rc; 96 97 if (monhdr->datalen > MONWRITE_MAX_DATALEN || 98 monhdr->mon_function > MONWRITE_START_CONFIG || 99 monhdr->hdrlen != sizeof(struct monwrite_hdr)) 100 return -EINVAL; 101 monbuf = NULL; 102 if (monhdr->mon_function != MONWRITE_GEN_EVENT) 103 monbuf = monwrite_find_hdr(monpriv, monhdr); 104 if (monbuf) { 105 if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) { 106 monhdr->datalen = monbuf->hdr.datalen; 107 rc = monwrite_diag(monhdr, monbuf->data, 108 APPLDATA_STOP_REC); 109 list_del(&monbuf->list); 110 mon_buf_count--; 111 kfree(monbuf->data); 112 kfree(monbuf); 113 monbuf = NULL; 114 } 115 } else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) { 116 if (mon_buf_count >= mon_max_bufs) 117 return -ENOSPC; 118 monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL); 119 if (!monbuf) 120 return -ENOMEM; 121 monbuf->data = kzalloc(monhdr->datalen, 122 GFP_KERNEL | GFP_DMA); 123 if (!monbuf->data) { 124 kfree(monbuf); 125 return -ENOMEM; 126 } 127 monbuf->hdr = *monhdr; 128 list_add_tail(&monbuf->list, &monpriv->list); 129 if (monhdr->mon_function != MONWRITE_GEN_EVENT) 130 mon_buf_count++; 131 } 132 monpriv->current_buf = monbuf; 133 return 0; 134 } 135 136 static int monwrite_new_data(struct mon_private *monpriv) 137 { 138 struct monwrite_hdr *monhdr = &monpriv->hdr; 139 struct mon_buf *monbuf = monpriv->current_buf; 140 int rc = 0; 141 142 switch (monhdr->mon_function) { 143 case MONWRITE_START_INTERVAL: 144 if (!monbuf->diag_done) { 145 rc = monwrite_diag(monhdr, monbuf->data, 146 APPLDATA_START_INTERVAL_REC); 147 monbuf->diag_done = 1; 148 } 149 break; 150 case MONWRITE_START_CONFIG: 151 if (!monbuf->diag_done) { 152 rc = monwrite_diag(monhdr, monbuf->data, 153 APPLDATA_START_CONFIG_REC); 154 monbuf->diag_done = 1; 155 } 156 break; 157 case MONWRITE_GEN_EVENT: 158 rc = monwrite_diag(monhdr, monbuf->data, 159 APPLDATA_GEN_EVENT_REC); 160 list_del(&monpriv->current_buf->list); 161 kfree(monpriv->current_buf->data); 162 kfree(monpriv->current_buf); 163 monpriv->current_buf = NULL; 164 break; 165 default: 166 /* monhdr->mon_function is checked in monwrite_new_hdr */ 167 BUG(); 168 } 169 return rc; 170 } 171 172 /* 173 * file operations 174 */ 175 176 static int monwrite_open(struct inode *inode, struct file *filp) 177 { 178 struct mon_private *monpriv; 179 180 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL); 181 if (!monpriv) 182 return -ENOMEM; 183 lock_kernel(); 184 INIT_LIST_HEAD(&monpriv->list); 185 monpriv->hdr_to_read = sizeof(monpriv->hdr); 186 mutex_init(&monpriv->thread_mutex); 187 filp->private_data = monpriv; 188 unlock_kernel(); 189 return nonseekable_open(inode, filp); 190 } 191 192 static int monwrite_close(struct inode *inode, struct file *filp) 193 { 194 struct mon_private *monpriv = filp->private_data; 195 struct mon_buf *entry, *next; 196 197 list_for_each_entry_safe(entry, next, &monpriv->list, list) { 198 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT) 199 monwrite_diag(&entry->hdr, entry->data, 200 APPLDATA_STOP_REC); 201 mon_buf_count--; 202 list_del(&entry->list); 203 kfree(entry->data); 204 kfree(entry); 205 } 206 kfree(monpriv); 207 return 0; 208 } 209 210 static ssize_t monwrite_write(struct file *filp, const char __user *data, 211 size_t count, loff_t *ppos) 212 { 213 struct mon_private *monpriv = filp->private_data; 214 size_t len, written; 215 void *to; 216 int rc; 217 218 mutex_lock(&monpriv->thread_mutex); 219 for (written = 0; written < count; ) { 220 if (monpriv->hdr_to_read) { 221 len = min(count - written, monpriv->hdr_to_read); 222 to = (char *) &monpriv->hdr + 223 sizeof(monpriv->hdr) - monpriv->hdr_to_read; 224 if (copy_from_user(to, data + written, len)) { 225 rc = -EFAULT; 226 goto out_error; 227 } 228 monpriv->hdr_to_read -= len; 229 written += len; 230 if (monpriv->hdr_to_read > 0) 231 continue; 232 rc = monwrite_new_hdr(monpriv); 233 if (rc) 234 goto out_error; 235 monpriv->data_to_read = monpriv->current_buf ? 236 monpriv->current_buf->hdr.datalen : 0; 237 } 238 239 if (monpriv->data_to_read) { 240 len = min(count - written, monpriv->data_to_read); 241 to = monpriv->current_buf->data + 242 monpriv->hdr.datalen - monpriv->data_to_read; 243 if (copy_from_user(to, data + written, len)) { 244 rc = -EFAULT; 245 goto out_error; 246 } 247 monpriv->data_to_read -= len; 248 written += len; 249 if (monpriv->data_to_read > 0) 250 continue; 251 rc = monwrite_new_data(monpriv); 252 if (rc) 253 goto out_error; 254 } 255 monpriv->hdr_to_read = sizeof(monpriv->hdr); 256 } 257 mutex_unlock(&monpriv->thread_mutex); 258 return written; 259 260 out_error: 261 monpriv->data_to_read = 0; 262 monpriv->hdr_to_read = sizeof(struct monwrite_hdr); 263 mutex_unlock(&monpriv->thread_mutex); 264 return rc; 265 } 266 267 static const struct file_operations monwrite_fops = { 268 .owner = THIS_MODULE, 269 .open = &monwrite_open, 270 .release = &monwrite_close, 271 .write = &monwrite_write, 272 }; 273 274 static struct miscdevice mon_dev = { 275 .name = "monwriter", 276 .fops = &monwrite_fops, 277 .minor = MISC_DYNAMIC_MINOR, 278 }; 279 280 /* 281 * module init/exit 282 */ 283 284 static int __init mon_init(void) 285 { 286 if (MACHINE_IS_VM) 287 return misc_register(&mon_dev); 288 else 289 return -ENODEV; 290 } 291 292 static void __exit mon_exit(void) 293 { 294 WARN_ON(misc_deregister(&mon_dev) != 0); 295 } 296 297 module_init(mon_init); 298 module_exit(mon_exit); 299 300 module_param_named(max_bufs, mon_max_bufs, int, 0644); 301 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers " 302 "that can be active at one time"); 303 304 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>"); 305 MODULE_DESCRIPTION("Character device driver for writing z/VM " 306 "APPLDATA monitor records."); 307 MODULE_LICENSE("GPL"); 308