1/* 2 * Simulated Ethernet Driver 3 * 4 * Copyright (C) 1999-2001, 2003 Hewlett-Packard Co 5 * Stephane Eranian <eranian@hpl.hp.com> 6 */ 7#include <linux/kernel.h> 8#include <linux/sched.h> 9#include <linux/types.h> 10#include <linux/in.h> 11#include <linux/string.h> 12#include <linux/init.h> 13#include <linux/errno.h> 14#include <linux/interrupt.h> 15#include <linux/netdevice.h> 16#include <linux/etherdevice.h> 17#include <linux/inetdevice.h> 18#include <linux/if_ether.h> 19#include <linux/if_arp.h> 20#include <linux/skbuff.h> 21#include <linux/notifier.h> 22#include <linux/bitops.h> 23#include <asm/irq.h> 24#include <asm/hpsim.h> 25 26#include "hpsim_ssc.h" 27 28#define SIMETH_RECV_MAX 10 29 30/* 31 * Maximum possible received frame for Ethernet. 32 * We preallocate an sk_buff of that size to avoid costly 33 * memcpy for temporary buffer into sk_buff. We do basically 34 * what's done in other drivers, like eepro with a ring. 35 * The difference is, of course, that we don't have real DMA !!! 36 */ 37#define SIMETH_FRAME_SIZE ETH_FRAME_LEN 38 39 40#define NETWORK_INTR 8 41 42struct simeth_local { 43 struct net_device_stats stats; 44 int simfd; /* descriptor in the simulator */ 45}; 46 47static int simeth_probe1(void); 48static int simeth_open(struct net_device *dev); 49static int simeth_close(struct net_device *dev); 50static int simeth_tx(struct sk_buff *skb, struct net_device *dev); 51static int simeth_rx(struct net_device *dev); 52static struct net_device_stats *simeth_get_stats(struct net_device *dev); 53static irqreturn_t simeth_interrupt(int irq, void *dev_id); 54static void set_multicast_list(struct net_device *dev); 55static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr); 56 57static char *simeth_version="0.3"; 58 59/* 60 * This variable is used to establish a mapping between the Linux/ia64 kernel 61 * and the host linux kernel. 62 * 63 * As of today, we support only one card, even though most of the code 64 * is ready for many more. The mapping is then: 65 * linux/ia64 -> linux/x86 66 * eth0 -> eth1 67 * 68 * In the future, we some string operations, we could easily support up 69 * to 10 cards (0-9). 70 * 71 * The default mapping can be changed on the kernel command line by 72 * specifying simeth=ethX (or whatever string you want). 73 */ 74static char *simeth_device="eth0"; /* default host interface to use */ 75 76 77 78static volatile unsigned int card_count; /* how many cards "found" so far */ 79static int simeth_debug; /* set to 1 to get debug information */ 80 81/* 82 * Used to catch IFF_UP & IFF_DOWN events 83 */ 84static struct notifier_block simeth_dev_notifier = { 85 simeth_device_event, 86 NULL 87}; 88 89 90/* 91 * Function used when using a kernel command line option. 92 * 93 * Format: simeth=interface_name (like eth0) 94 */ 95static int __init 96simeth_setup(char *str) 97{ 98 simeth_device = str; 99 return 1; 100} 101 102__setup("simeth=", simeth_setup); 103 104/* 105 * Function used to probe for simeth devices when not installed 106 * as a loadable module 107 */ 108 109int __init 110simeth_probe (void) 111{ 112 int r; 113 114 printk(KERN_INFO "simeth: v%s\n", simeth_version); 115 116 r = simeth_probe1(); 117 118 if (r == 0) register_netdevice_notifier(&simeth_dev_notifier); 119 120 return r; 121} 122 123static inline int 124netdev_probe(char *name, unsigned char *ether) 125{ 126 return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE); 127} 128 129 130static inline int 131netdev_attach(int fd, int irq, unsigned int ipaddr) 132{ 133 /* this puts the host interface in the right mode (start interrupting) */ 134 return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH); 135} 136 137 138static inline int 139netdev_detach(int fd) 140{ 141 /* 142 * inactivate the host interface (don't interrupt anymore) */ 143 return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH); 144} 145 146static inline int 147netdev_send(int fd, unsigned char *buf, unsigned int len) 148{ 149 return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND); 150} 151 152static inline int 153netdev_read(int fd, unsigned char *buf, unsigned int len) 154{ 155 return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV); 156} 157 158static const struct net_device_ops simeth_netdev_ops = { 159 .ndo_open = simeth_open, 160 .ndo_stop = simeth_close, 161 .ndo_start_xmit = simeth_tx, 162 .ndo_get_stats = simeth_get_stats, 163 .ndo_set_rx_mode = set_multicast_list, /* not yet used */ 164 165}; 166 167/* 168 * Function shared with module code, so cannot be in init section 169 * 170 * So far this function "detects" only one card (test_&_set) but could 171 * be extended easily. 172 * 173 * Return: 174 * - -ENODEV is no device found 175 * - -ENOMEM is no more memory 176 * - 0 otherwise 177 */ 178static int 179simeth_probe1(void) 180{ 181 unsigned char mac_addr[ETH_ALEN]; 182 struct simeth_local *local; 183 struct net_device *dev; 184 int fd, err, rc; 185 186 /* 187 * XXX Fix me 188 * let's support just one card for now 189 */ 190 if (test_and_set_bit(0, &card_count)) 191 return -ENODEV; 192 193 /* 194 * check with the simulator for the device 195 */ 196 fd = netdev_probe(simeth_device, mac_addr); 197 if (fd == -1) 198 return -ENODEV; 199 200 dev = alloc_etherdev(sizeof(struct simeth_local)); 201 if (!dev) 202 return -ENOMEM; 203 204 memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr)); 205 206 local = netdev_priv(dev); 207 local->simfd = fd; /* keep track of underlying file descriptor */ 208 209 dev->netdev_ops = &simeth_netdev_ops; 210 211 err = register_netdev(dev); 212 if (err) { 213 free_netdev(dev); 214 return err; 215 } 216 217 /* 218 * attach the interrupt in the simulator, this does enable interrupts 219 * until a netdev_attach() is called 220 */ 221 if ((rc = hpsim_get_irq(NETWORK_INTR)) < 0) 222 panic("%s: out of interrupt vectors!\n", __func__); 223 dev->irq = rc; 224 225 printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr=%pm, IRQ %d\n", 226 dev->name, simeth_device, local->simfd, dev->dev_addr, dev->irq); 227 228 return 0; 229} 230 231/* 232 * actually binds the device to an interrupt vector 233 */ 234static int 235simeth_open(struct net_device *dev) 236{ 237 if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) { 238 printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq); 239 return -EAGAIN; 240 } 241 242 netif_start_queue(dev); 243 244 return 0; 245} 246 247/* copied from lapbether.c */ 248static __inline__ int dev_is_ethdev(struct net_device *dev) 249{ 250 return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5)); 251} 252 253 254/* 255 * Handler for IFF_UP or IFF_DOWN 256 * 257 * The reason for that is that we don't want to be interrupted when the 258 * interface is down. There is no way to unconnect in the simualtor. Instead 259 * we use this function to shutdown packet processing in the frame filter 260 * in the simulator. Thus no interrupts are generated 261 * 262 * 263 * That's also the place where we pass the IP address of this device to the 264 * simulator so that that we can start filtering packets for it 265 * 266 * There may be a better way of doing this, but I don't know which yet. 267 */ 268static int 269simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr) 270{ 271 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 272 struct simeth_local *local; 273 struct in_device *in_dev; 274 struct in_ifaddr **ifap = NULL; 275 struct in_ifaddr *ifa = NULL; 276 int r; 277 278 279 if ( ! dev ) { 280 printk(KERN_WARNING "simeth_device_event dev=0\n"); 281 return NOTIFY_DONE; 282 } 283 284 if (dev_net(dev) != &init_net) 285 return NOTIFY_DONE; 286 287 if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE; 288 289 /* 290 * Check whether or not it's for an ethernet device 291 * 292 * XXX Fixme: This works only as long as we support one 293 * type of ethernet device. 294 */ 295 if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE; 296 297 if ((in_dev=dev->ip_ptr) != NULL) { 298 for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next) 299 if (strcmp(dev->name, ifa->ifa_label) == 0) break; 300 } 301 if ( ifa == NULL ) { 302 printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name); 303 return NOTIFY_DONE; 304 } 305 306 printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n", 307 dev->name, ntohl(ifa->ifa_local)); 308 309 /* 310 * XXX Fix me 311 * if the device was up, and we're simply reconfiguring it, not sure 312 * we get DOWN then UP. 313 */ 314 315 local = netdev_priv(dev); 316 /* now do it for real */ 317 r = event == NETDEV_UP ? 318 netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)): 319 netdev_detach(local->simfd); 320 321 printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n", 322 event == NETDEV_UP ? "attach":"detach", r); 323 324 return NOTIFY_DONE; 325} 326 327static int 328simeth_close(struct net_device *dev) 329{ 330 netif_stop_queue(dev); 331 332 free_irq(dev->irq, dev); 333 334 return 0; 335} 336 337/* 338 * Only used for debug 339 */ 340static void 341frame_print(unsigned char *from, unsigned char *frame, int len) 342{ 343 int i; 344 345 printk("%s: (%d) %02x", from, len, frame[0] & 0xff); 346 for(i=1; i < 6; i++ ) { 347 printk(":%02x", frame[i] &0xff); 348 } 349 printk(" %2x", frame[6] &0xff); 350 for(i=7; i < 12; i++ ) { 351 printk(":%02x", frame[i] &0xff); 352 } 353 printk(" [%02x%02x]\n", frame[12], frame[13]); 354 355 for(i=14; i < len; i++ ) { 356 printk("%02x ", frame[i] &0xff); 357 if ( (i%10)==0) printk("\n"); 358 } 359 printk("\n"); 360} 361 362 363/* 364 * Function used to transmit of frame, very last one on the path before 365 * going to the simulator. 366 */ 367static int 368simeth_tx(struct sk_buff *skb, struct net_device *dev) 369{ 370 struct simeth_local *local = netdev_priv(dev); 371 372#if 0 373 /* ensure we have at least ETH_ZLEN bytes (min frame size) */ 374 unsigned int length = ETH_ZLEN < skb->len ? skb->len : ETH_ZLEN; 375 /* Where do the extra padding bytes comes from inthe skbuff ? */ 376#else 377 /* the real driver in the host system is going to take care of that 378 * or maybe it's the NIC itself. 379 */ 380 unsigned int length = skb->len; 381#endif 382 383 local->stats.tx_bytes += skb->len; 384 local->stats.tx_packets++; 385 386 387 if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length); 388 389 netdev_send(local->simfd, skb->data, length); 390 391 /* 392 * we are synchronous on write, so we don't simulate a 393 * trasnmit complete interrupt, thus we don't need to arm a tx 394 */ 395 396 dev_kfree_skb(skb); 397 return NETDEV_TX_OK; 398} 399 400static inline struct sk_buff * 401make_new_skb(struct net_device *dev) 402{ 403 struct sk_buff *nskb; 404 405 /* 406 * The +2 is used to make sure that the IP header is nicely 407 * aligned (on 4byte boundary I assume 14+2=16) 408 */ 409 nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2); 410 if ( nskb == NULL ) { 411 printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name); 412 return NULL; 413 } 414 415 skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */ 416 417 skb_put(nskb,SIMETH_FRAME_SIZE); 418 419 return nskb; 420} 421 422/* 423 * called from interrupt handler to process a received frame 424 */ 425static int 426simeth_rx(struct net_device *dev) 427{ 428 struct simeth_local *local; 429 struct sk_buff *skb; 430 int len; 431 int rcv_count = SIMETH_RECV_MAX; 432 433 local = netdev_priv(dev); 434 /* 435 * the loop concept has been borrowed from other drivers 436 * looks to me like it's a throttling thing to avoid pushing to many 437 * packets at one time into the stack. Making sure we can process them 438 * upstream and make forward progress overall 439 */ 440 do { 441 if ( (skb=make_new_skb(dev)) == NULL ) { 442 printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name); 443 local->stats.rx_dropped++; 444 return 0; 445 } 446 /* 447 * Read only one frame at a time 448 */ 449 len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE); 450 if ( len == 0 ) { 451 if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n", 452 dev->name, SIMETH_RECV_MAX-rcv_count); 453 break; 454 } 455#if 0 456 /* 457 * XXX Fix me 458 * Should really do a csum+copy here 459 */ 460 skb_copy_to_linear_data(skb, frame, len); 461#endif 462 skb->protocol = eth_type_trans(skb, dev); 463 464 if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len); 465 466 /* 467 * push the packet up & trigger software interrupt 468 */ 469 netif_rx(skb); 470 471 local->stats.rx_packets++; 472 local->stats.rx_bytes += len; 473 474 } while ( --rcv_count ); 475 476 return len; /* 0 = nothing left to read, otherwise, we can try again */ 477} 478 479/* 480 * Interrupt handler (Yes, we can do it too !!!) 481 */ 482static irqreturn_t 483simeth_interrupt(int irq, void *dev_id) 484{ 485 struct net_device *dev = dev_id; 486 487 /* 488 * very simple loop because we get interrupts only when receiving 489 */ 490 while (simeth_rx(dev)); 491 return IRQ_HANDLED; 492} 493 494static struct net_device_stats * 495simeth_get_stats(struct net_device *dev) 496{ 497 struct simeth_local *local = netdev_priv(dev); 498 499 return &local->stats; 500} 501 502/* fake multicast ability */ 503static void 504set_multicast_list(struct net_device *dev) 505{ 506 printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name); 507} 508 509__initcall(simeth_probe); 510