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