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/system.h> 24#include <asm/irq.h> 25#include <asm/hpsim.h> 26 27#include "hpsim_ssc.h" 28 29#define SIMETH_RECV_MAX 10 30 31/* 32 * Maximum possible received frame for Ethernet. 33 * We preallocate an sk_buff of that size to avoid costly 34 * memcpy for temporary buffer into sk_buff. We do basically 35 * what's done in other drivers, like eepro with a ring. 36 * The difference is, of course, that we don't have real DMA !!! 37 */ 38#define SIMETH_FRAME_SIZE ETH_FRAME_LEN 39 40 41#define NETWORK_INTR 8 42 43struct simeth_local { 44 struct net_device_stats stats; 45 int simfd; /* descriptor in the simulator */ 46}; 47 48static int simeth_probe1(void); 49static int simeth_open(struct net_device *dev); 50static int simeth_close(struct net_device *dev); 51static int simeth_tx(struct sk_buff *skb, struct net_device *dev); 52static int simeth_rx(struct net_device *dev); 53static struct net_device_stats *simeth_get_stats(struct net_device *dev); 54static irqreturn_t simeth_interrupt(int irq, void *dev_id); 55static void set_multicast_list(struct net_device *dev); 56static int simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr); 57 58static char *simeth_version="0.3"; 59 60/* 61 * This variable is used to establish a mapping between the Linux/ia64 kernel 62 * and the host linux kernel. 63 * 64 * As of today, we support only one card, even though most of the code 65 * is ready for many more. The mapping is then: 66 * linux/ia64 -> linux/x86 67 * eth0 -> eth1 68 * 69 * In the future, we some string operations, we could easily support up 70 * to 10 cards (0-9). 71 * 72 * The default mapping can be changed on the kernel command line by 73 * specifying simeth=ethX (or whatever string you want). 74 */ 75static char *simeth_device="eth0"; /* default host interface to use */ 76 77 78 79static volatile unsigned int card_count; /* how many cards "found" so far */ 80static int simeth_debug; /* set to 1 to get debug information */ 81 82/* 83 * Used to catch IFF_UP & IFF_DOWN events 84 */ 85static struct notifier_block simeth_dev_notifier = { 86 simeth_device_event, 87 NULL 88}; 89 90 91/* 92 * Function used when using a kernel command line option. 93 * 94 * Format: simeth=interface_name (like eth0) 95 */ 96static int __init 97simeth_setup(char *str) 98{ 99 simeth_device = str; 100 return 1; 101} 102 103__setup("simeth=", simeth_setup); 104 105/* 106 * Function used to probe for simeth devices when not installed 107 * as a loadable module 108 */ 109 110int __init 111simeth_probe (void) 112{ 113 int r; 114 115 printk(KERN_INFO "simeth: v%s\n", simeth_version); 116 117 r = simeth_probe1(); 118 119 if (r == 0) register_netdevice_notifier(&simeth_dev_notifier); 120 121 return r; 122} 123 124static inline int 125netdev_probe(char *name, unsigned char *ether) 126{ 127 return ia64_ssc(__pa(name), __pa(ether), 0,0, SSC_NETDEV_PROBE); 128} 129 130 131static inline int 132netdev_connect(int irq) 133{ 134 ia64_ssc_connect_irq(NETWORK_INTR, irq); 135 return 0; 136} 137 138static inline int 139netdev_attach(int fd, int irq, unsigned int ipaddr) 140{ 141 /* this puts the host interface in the right mode (start interrupting) */ 142 return ia64_ssc(fd, ipaddr, 0,0, SSC_NETDEV_ATTACH); 143} 144 145 146static inline int 147netdev_detach(int fd) 148{ 149 /* 150 * inactivate the host interface (don't interrupt anymore) */ 151 return ia64_ssc(fd, 0,0,0, SSC_NETDEV_DETACH); 152} 153 154static inline int 155netdev_send(int fd, unsigned char *buf, unsigned int len) 156{ 157 return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_SEND); 158} 159 160static inline int 161netdev_read(int fd, unsigned char *buf, unsigned int len) 162{ 163 return ia64_ssc(fd, __pa(buf), len, 0, SSC_NETDEV_RECV); 164} 165 166static const struct net_device_ops simeth_netdev_ops = { 167 .ndo_open = simeth_open, 168 .ndo_stop = simeth_close, 169 .ndo_start_xmit = simeth_tx, 170 .ndo_get_stats = simeth_get_stats, 171 .ndo_set_multicast_list = set_multicast_list, /* not yet used */ 172 173}; 174 175/* 176 * Function shared with module code, so cannot be in init section 177 * 178 * So far this function "detects" only one card (test_&_set) but could 179 * be extended easily. 180 * 181 * Return: 182 * - -ENODEV is no device found 183 * - -ENOMEM is no more memory 184 * - 0 otherwise 185 */ 186static int 187simeth_probe1(void) 188{ 189 unsigned char mac_addr[ETH_ALEN]; 190 struct simeth_local *local; 191 struct net_device *dev; 192 int fd, i, err, rc; 193 194 if (test_and_set_bit(0, &card_count)) 195 return -ENODEV; 196 197 /* 198 * check with the simulator for the device 199 */ 200 fd = netdev_probe(simeth_device, mac_addr); 201 if (fd == -1) 202 return -ENODEV; 203 204 dev = alloc_etherdev(sizeof(struct simeth_local)); 205 if (!dev) 206 return -ENOMEM; 207 208 memcpy(dev->dev_addr, mac_addr, sizeof(mac_addr)); 209 210 local = netdev_priv(dev); 211 local->simfd = fd; /* keep track of underlying file descriptor */ 212 213 dev->netdev_ops = &simeth_netdev_ops; 214 215 err = register_netdev(dev); 216 if (err) { 217 free_netdev(dev); 218 return err; 219 } 220 221 if ((rc = assign_irq_vector(AUTO_ASSIGN)) < 0) 222 panic("%s: out of interrupt vectors!\n", __func__); 223 dev->irq = rc; 224 225 /* 226 * attach the interrupt in the simulator, this does enable interrupts 227 * until a netdev_attach() is called 228 */ 229 netdev_connect(dev->irq); 230 231 printk(KERN_INFO "%s: hosteth=%s simfd=%d, HwAddr", 232 dev->name, simeth_device, local->simfd); 233 for(i = 0; i < ETH_ALEN; i++) { 234 printk(" %2.2x", dev->dev_addr[i]); 235 } 236 printk(", IRQ %d\n", dev->irq); 237 238 return 0; 239} 240 241/* 242 * actually binds the device to an interrupt vector 243 */ 244static int 245simeth_open(struct net_device *dev) 246{ 247 if (request_irq(dev->irq, simeth_interrupt, 0, "simeth", dev)) { 248 printk(KERN_WARNING "simeth: unable to get IRQ %d.\n", dev->irq); 249 return -EAGAIN; 250 } 251 252 netif_start_queue(dev); 253 254 return 0; 255} 256 257/* copied from lapbether.c */ 258static __inline__ int dev_is_ethdev(struct net_device *dev) 259{ 260 return ( dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5)); 261} 262 263 264/* 265 * Handler for IFF_UP or IFF_DOWN 266 * 267 * The reason for that is that we don't want to be interrupted when the 268 * interface is down. There is no way to unconnect in the simualtor. Instead 269 * we use this function to shutdown packet processing in the frame filter 270 * in the simulator. Thus no interrupts are generated 271 * 272 * 273 * That's also the place where we pass the IP address of this device to the 274 * simulator so that that we can start filtering packets for it 275 * 276 * There may be a better way of doing this, but I don't know which yet. 277 */ 278static int 279simeth_device_event(struct notifier_block *this,unsigned long event, void *ptr) 280{ 281 struct net_device *dev = ptr; 282 struct simeth_local *local; 283 struct in_device *in_dev; 284 struct in_ifaddr **ifap = NULL; 285 struct in_ifaddr *ifa = NULL; 286 int r; 287 288 289 if ( ! dev ) { 290 printk(KERN_WARNING "simeth_device_event dev=0\n"); 291 return NOTIFY_DONE; 292 } 293 294 if (dev_net(dev) != &init_net) 295 return NOTIFY_DONE; 296 297 if ( event != NETDEV_UP && event != NETDEV_DOWN ) return NOTIFY_DONE; 298 299 if ( !dev_is_ethdev(dev) ) return NOTIFY_DONE; 300 301 if ((in_dev=dev->ip_ptr) != NULL) { 302 for (ifap=&in_dev->ifa_list; (ifa=*ifap) != NULL; ifap=&ifa->ifa_next) 303 if (strcmp(dev->name, ifa->ifa_label) == 0) break; 304 } 305 if ( ifa == NULL ) { 306 printk(KERN_ERR "simeth_open: can't find device %s's ifa\n", dev->name); 307 return NOTIFY_DONE; 308 } 309 310 printk(KERN_INFO "simeth_device_event: %s ipaddr=0x%x\n", 311 dev->name, ntohl(ifa->ifa_local)); 312 313 314 local = netdev_priv(dev); 315 /* now do it for real */ 316 r = event == NETDEV_UP ? 317 netdev_attach(local->simfd, dev->irq, ntohl(ifa->ifa_local)): 318 netdev_detach(local->simfd); 319 320 printk(KERN_INFO "simeth: netdev_attach/detach: event=%s ->%d\n", 321 event == NETDEV_UP ? "attach":"detach", r); 322 323 return NOTIFY_DONE; 324} 325 326static int 327simeth_close(struct net_device *dev) 328{ 329 netif_stop_queue(dev); 330 331 free_irq(dev->irq, dev); 332 333 return 0; 334} 335 336/* 337 * Only used for debug 338 */ 339static void 340frame_print(unsigned char *from, unsigned char *frame, int len) 341{ 342 int i; 343 344 printk("%s: (%d) %02x", from, len, frame[0] & 0xff); 345 for(i=1; i < 6; i++ ) { 346 printk(":%02x", frame[i] &0xff); 347 } 348 printk(" %2x", frame[6] &0xff); 349 for(i=7; i < 12; i++ ) { 350 printk(":%02x", frame[i] &0xff); 351 } 352 printk(" [%02x%02x]\n", frame[12], frame[13]); 353 354 for(i=14; i < len; i++ ) { 355 printk("%02x ", frame[i] &0xff); 356 if ( (i%10)==0) printk("\n"); 357 } 358 printk("\n"); 359} 360 361 362/* 363 * Function used to transmit of frame, very last one on the path before 364 * going to the simulator. 365 */ 366static int 367simeth_tx(struct sk_buff *skb, struct net_device *dev) 368{ 369 struct simeth_local *local = netdev_priv(dev); 370 371 /* the real driver in the host system is going to take care of that 372 * or maybe it's the NIC itself. 373 */ 374 unsigned int length = skb->len; 375 376 local->stats.tx_bytes += skb->len; 377 local->stats.tx_packets++; 378 379 380 if (simeth_debug > 5) frame_print("simeth_tx", skb->data, length); 381 382 netdev_send(local->simfd, skb->data, length); 383 384 /* 385 * we are synchronous on write, so we don't simulate a 386 * trasnmit complete interrupt, thus we don't need to arm a tx 387 */ 388 389 dev_kfree_skb(skb); 390 return NETDEV_TX_OK; 391} 392 393static inline struct sk_buff * 394make_new_skb(struct net_device *dev) 395{ 396 struct sk_buff *nskb; 397 398 /* 399 * The +2 is used to make sure that the IP header is nicely 400 * aligned (on 4byte boundary I assume 14+2=16) 401 */ 402 nskb = dev_alloc_skb(SIMETH_FRAME_SIZE + 2); 403 if ( nskb == NULL ) { 404 printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name); 405 return NULL; 406 } 407 408 skb_reserve(nskb, 2); /* Align IP on 16 byte boundaries */ 409 410 skb_put(nskb,SIMETH_FRAME_SIZE); 411 412 return nskb; 413} 414 415/* 416 * called from interrupt handler to process a received frame 417 */ 418static int 419simeth_rx(struct net_device *dev) 420{ 421 struct simeth_local *local; 422 struct sk_buff *skb; 423 int len; 424 int rcv_count = SIMETH_RECV_MAX; 425 426 local = netdev_priv(dev); 427 /* 428 * the loop concept has been borrowed from other drivers 429 * looks to me like it's a throttling thing to avoid pushing to many 430 * packets at one time into the stack. Making sure we can process them 431 * upstream and make forward progress overall 432 */ 433 do { 434 if ( (skb=make_new_skb(dev)) == NULL ) { 435 printk(KERN_NOTICE "%s: memory squeeze. dropping packet.\n", dev->name); 436 local->stats.rx_dropped++; 437 return 0; 438 } 439 /* 440 * Read only one frame at a time 441 */ 442 len = netdev_read(local->simfd, skb->data, SIMETH_FRAME_SIZE); 443 if ( len == 0 ) { 444 if ( simeth_debug > 0 ) printk(KERN_WARNING "%s: count=%d netdev_read=0\n", 445 dev->name, SIMETH_RECV_MAX-rcv_count); 446 break; 447 } 448 skb->protocol = eth_type_trans(skb, dev); 449 450 if ( simeth_debug > 6 ) frame_print("simeth_rx", skb->data, len); 451 452 /* 453 * push the packet up & trigger software interrupt 454 */ 455 netif_rx(skb); 456 457 local->stats.rx_packets++; 458 local->stats.rx_bytes += len; 459 460 } while ( --rcv_count ); 461 462 return len; /* 0 = nothing left to read, otherwise, we can try again */ 463} 464 465/* 466 * Interrupt handler (Yes, we can do it too !!!) 467 */ 468static irqreturn_t 469simeth_interrupt(int irq, void *dev_id) 470{ 471 struct net_device *dev = dev_id; 472 473 /* 474 * very simple loop because we get interrupts only when receiving 475 */ 476 while (simeth_rx(dev)); 477 return IRQ_HANDLED; 478} 479 480static struct net_device_stats * 481simeth_get_stats(struct net_device *dev) 482{ 483 struct simeth_local *local = netdev_priv(dev); 484 485 return &local->stats; 486} 487 488/* fake multicast ability */ 489static void 490set_multicast_list(struct net_device *dev) 491{ 492 printk(KERN_WARNING "%s: set_multicast_list called\n", dev->name); 493} 494 495__initcall(simeth_probe); 496