[PATCH] prism54: fix potential race in reset scheduling
[linux-2.6] / drivers / net / rionet.c
1 /*
2  * rionet - Ethernet driver over RapidIO messaging services
3  *
4  * Copyright 2005 MontaVista Software, Inc.
5  * Matt Porter <mporter@kernel.crashing.org>
6  *
7  * This program is free software; you can redistribute  it and/or modify it
8  * under  the terms of  the GNU General  Public License as published by the
9  * Free Software Foundation;  either version 2 of the  License, or (at your
10  * option) any later version.
11  */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/delay.h>
17 #include <linux/rio.h>
18 #include <linux/rio_drv.h>
19 #include <linux/rio_ids.h>
20
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/skbuff.h>
24 #include <linux/crc32.h>
25 #include <linux/ethtool.h>
26
27 #define DRV_NAME        "rionet"
28 #define DRV_VERSION     "0.2"
29 #define DRV_AUTHOR      "Matt Porter <mporter@kernel.crashing.org>"
30 #define DRV_DESC        "Ethernet over RapidIO"
31
32 MODULE_AUTHOR(DRV_AUTHOR);
33 MODULE_DESCRIPTION(DRV_DESC);
34 MODULE_LICENSE("GPL");
35
36 #define RIONET_DEFAULT_MSGLEVEL \
37                         (NETIF_MSG_DRV          | \
38                          NETIF_MSG_LINK         | \
39                          NETIF_MSG_RX_ERR       | \
40                          NETIF_MSG_TX_ERR)
41
42 #define RIONET_DOORBELL_JOIN    0x1000
43 #define RIONET_DOORBELL_LEAVE   0x1001
44
45 #define RIONET_MAILBOX          0
46
47 #define RIONET_TX_RING_SIZE     CONFIG_RIONET_TX_SIZE
48 #define RIONET_RX_RING_SIZE     CONFIG_RIONET_RX_SIZE
49
50 static LIST_HEAD(rionet_peers);
51
52 struct rionet_private {
53         struct rio_mport *mport;
54         struct sk_buff *rx_skb[RIONET_RX_RING_SIZE];
55         struct sk_buff *tx_skb[RIONET_TX_RING_SIZE];
56         struct net_device_stats stats;
57         int rx_slot;
58         int tx_slot;
59         int tx_cnt;
60         int ack_slot;
61         spinlock_t lock;
62         spinlock_t tx_lock;
63         u32 msg_enable;
64 };
65
66 struct rionet_peer {
67         struct list_head node;
68         struct rio_dev *rdev;
69         struct resource *res;
70 };
71
72 static int rionet_check = 0;
73 static int rionet_capable = 1;
74
75 /*
76  * This is a fast lookup table for for translating TX
77  * Ethernet packets into a destination RIO device. It
78  * could be made into a hash table to save memory depending
79  * on system trade-offs.
80  */
81 static struct rio_dev *rionet_active[RIO_MAX_ROUTE_ENTRIES];
82
83 #define is_rionet_capable(pef, src_ops, dst_ops)                \
84                         ((pef & RIO_PEF_INB_MBOX) &&            \
85                          (pef & RIO_PEF_INB_DOORBELL) &&        \
86                          (src_ops & RIO_SRC_OPS_DOORBELL) &&    \
87                          (dst_ops & RIO_DST_OPS_DOORBELL))
88 #define dev_rionet_capable(dev) \
89         is_rionet_capable(dev->pef, dev->src_ops, dev->dst_ops)
90
91 #define RIONET_MAC_MATCH(x)     (*(u32 *)x == 0x00010001)
92 #define RIONET_GET_DESTID(x)    (*(u16 *)(x + 4))
93
94 static struct net_device_stats *rionet_stats(struct net_device *ndev)
95 {
96         struct rionet_private *rnet = ndev->priv;
97         return &rnet->stats;
98 }
99
100 static int rionet_rx_clean(struct net_device *ndev)
101 {
102         int i;
103         int error = 0;
104         struct rionet_private *rnet = ndev->priv;
105         void *data;
106
107         i = rnet->rx_slot;
108
109         do {
110                 if (!rnet->rx_skb[i])
111                         continue;
112
113                 if (!(data = rio_get_inb_message(rnet->mport, RIONET_MAILBOX)))
114                         break;
115
116                 rnet->rx_skb[i]->data = data;
117                 skb_put(rnet->rx_skb[i], RIO_MAX_MSG_SIZE);
118                 rnet->rx_skb[i]->dev = ndev;
119                 rnet->rx_skb[i]->protocol =
120                     eth_type_trans(rnet->rx_skb[i], ndev);
121                 error = netif_rx(rnet->rx_skb[i]);
122
123                 if (error == NET_RX_DROP) {
124                         rnet->stats.rx_dropped++;
125                 } else if (error == NET_RX_BAD) {
126                         if (netif_msg_rx_err(rnet))
127                                 printk(KERN_WARNING "%s: bad rx packet\n",
128                                        DRV_NAME);
129                         rnet->stats.rx_errors++;
130                 } else {
131                         rnet->stats.rx_packets++;
132                         rnet->stats.rx_bytes += RIO_MAX_MSG_SIZE;
133                 }
134
135         } while ((i = (i + 1) % RIONET_RX_RING_SIZE) != rnet->rx_slot);
136
137         return i;
138 }
139
140 static void rionet_rx_fill(struct net_device *ndev, int end)
141 {
142         int i;
143         struct rionet_private *rnet = ndev->priv;
144
145         i = rnet->rx_slot;
146         do {
147                 rnet->rx_skb[i] = dev_alloc_skb(RIO_MAX_MSG_SIZE);
148
149                 if (!rnet->rx_skb[i])
150                         break;
151
152                 rio_add_inb_buffer(rnet->mport, RIONET_MAILBOX,
153                                    rnet->rx_skb[i]->data);
154         } while ((i = (i + 1) % RIONET_RX_RING_SIZE) != end);
155
156         rnet->rx_slot = i;
157 }
158
159 static int rionet_queue_tx_msg(struct sk_buff *skb, struct net_device *ndev,
160                                struct rio_dev *rdev)
161 {
162         struct rionet_private *rnet = ndev->priv;
163
164         rio_add_outb_message(rnet->mport, rdev, 0, skb->data, skb->len);
165         rnet->tx_skb[rnet->tx_slot] = skb;
166
167         rnet->stats.tx_packets++;
168         rnet->stats.tx_bytes += skb->len;
169
170         if (++rnet->tx_cnt == RIONET_TX_RING_SIZE)
171                 netif_stop_queue(ndev);
172
173         ++rnet->tx_slot;
174         rnet->tx_slot &= (RIONET_TX_RING_SIZE - 1);
175
176         if (netif_msg_tx_queued(rnet))
177                 printk(KERN_INFO "%s: queued skb %8.8x len %8.8x\n", DRV_NAME,
178                        (u32) skb, skb->len);
179
180         return 0;
181 }
182
183 static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
184 {
185         int i;
186         struct rionet_private *rnet = ndev->priv;
187         struct ethhdr *eth = (struct ethhdr *)skb->data;
188         u16 destid;
189         unsigned long flags;
190
191         local_irq_save(flags);
192         if (!spin_trylock(&rnet->tx_lock)) {
193                 local_irq_restore(flags);
194                 return NETDEV_TX_LOCKED;
195         }
196
197         if ((rnet->tx_cnt + 1) > RIONET_TX_RING_SIZE) {
198                 netif_stop_queue(ndev);
199                 spin_unlock_irqrestore(&rnet->tx_lock, flags);
200                 printk(KERN_ERR "%s: BUG! Tx Ring full when queue awake!\n",
201                        ndev->name);
202                 return NETDEV_TX_BUSY;
203         }
204
205         if (eth->h_dest[0] & 0x01) {
206                 for (i = 0; i < RIO_MAX_ROUTE_ENTRIES; i++)
207                         if (rionet_active[i])
208                                 rionet_queue_tx_msg(skb, ndev,
209                                                     rionet_active[i]);
210         } else if (RIONET_MAC_MATCH(eth->h_dest)) {
211                 destid = RIONET_GET_DESTID(eth->h_dest);
212                 if (rionet_active[destid])
213                         rionet_queue_tx_msg(skb, ndev, rionet_active[destid]);
214         }
215
216         spin_unlock_irqrestore(&rnet->tx_lock, flags);
217
218         return 0;
219 }
220
221 static void rionet_dbell_event(struct rio_mport *mport, void *dev_id, u16 sid, u16 tid,
222                                u16 info)
223 {
224         struct net_device *ndev = dev_id;
225         struct rionet_private *rnet = ndev->priv;
226         struct rionet_peer *peer;
227
228         if (netif_msg_intr(rnet))
229                 printk(KERN_INFO "%s: doorbell sid %4.4x tid %4.4x info %4.4x",
230                        DRV_NAME, sid, tid, info);
231         if (info == RIONET_DOORBELL_JOIN) {
232                 if (!rionet_active[sid]) {
233                         list_for_each_entry(peer, &rionet_peers, node) {
234                                 if (peer->rdev->destid == sid)
235                                         rionet_active[sid] = peer->rdev;
236                         }
237                         rio_mport_send_doorbell(mport, sid,
238                                                 RIONET_DOORBELL_JOIN);
239                 }
240         } else if (info == RIONET_DOORBELL_LEAVE) {
241                 rionet_active[sid] = NULL;
242         } else {
243                 if (netif_msg_intr(rnet))
244                         printk(KERN_WARNING "%s: unhandled doorbell\n",
245                                DRV_NAME);
246         }
247 }
248
249 static void rionet_inb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
250 {
251         int n;
252         struct net_device *ndev = dev_id;
253         struct rionet_private *rnet = (struct rionet_private *)ndev->priv;
254
255         if (netif_msg_intr(rnet))
256                 printk(KERN_INFO "%s: inbound message event, mbox %d slot %d\n",
257                        DRV_NAME, mbox, slot);
258
259         spin_lock(&rnet->lock);
260         if ((n = rionet_rx_clean(ndev)) != rnet->rx_slot)
261                 rionet_rx_fill(ndev, n);
262         spin_unlock(&rnet->lock);
263 }
264
265 static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
266 {
267         struct net_device *ndev = dev_id;
268         struct rionet_private *rnet = ndev->priv;
269
270         spin_lock(&rnet->lock);
271
272         if (netif_msg_intr(rnet))
273                 printk(KERN_INFO
274                        "%s: outbound message event, mbox %d slot %d\n",
275                        DRV_NAME, mbox, slot);
276
277         while (rnet->tx_cnt && (rnet->ack_slot != slot)) {
278                 /* dma unmap single */
279                 dev_kfree_skb_irq(rnet->tx_skb[rnet->ack_slot]);
280                 rnet->tx_skb[rnet->ack_slot] = NULL;
281                 ++rnet->ack_slot;
282                 rnet->ack_slot &= (RIONET_TX_RING_SIZE - 1);
283                 rnet->tx_cnt--;
284         }
285
286         if (rnet->tx_cnt < RIONET_TX_RING_SIZE)
287                 netif_wake_queue(ndev);
288
289         spin_unlock(&rnet->lock);
290 }
291
292 static int rionet_open(struct net_device *ndev)
293 {
294         int i, rc = 0;
295         struct rionet_peer *peer, *tmp;
296         u32 pwdcsr;
297         struct rionet_private *rnet = ndev->priv;
298
299         if (netif_msg_ifup(rnet))
300                 printk(KERN_INFO "%s: open\n", DRV_NAME);
301
302         if ((rc = rio_request_inb_dbell(rnet->mport,
303                                         (void *)ndev,
304                                         RIONET_DOORBELL_JOIN,
305                                         RIONET_DOORBELL_LEAVE,
306                                         rionet_dbell_event)) < 0)
307                 goto out;
308
309         if ((rc = rio_request_inb_mbox(rnet->mport,
310                                        (void *)ndev,
311                                        RIONET_MAILBOX,
312                                        RIONET_RX_RING_SIZE,
313                                        rionet_inb_msg_event)) < 0)
314                 goto out;
315
316         if ((rc = rio_request_outb_mbox(rnet->mport,
317                                         (void *)ndev,
318                                         RIONET_MAILBOX,
319                                         RIONET_TX_RING_SIZE,
320                                         rionet_outb_msg_event)) < 0)
321                 goto out;
322
323         /* Initialize inbound message ring */
324         for (i = 0; i < RIONET_RX_RING_SIZE; i++)
325                 rnet->rx_skb[i] = NULL;
326         rnet->rx_slot = 0;
327         rionet_rx_fill(ndev, 0);
328
329         rnet->tx_slot = 0;
330         rnet->tx_cnt = 0;
331         rnet->ack_slot = 0;
332
333         netif_carrier_on(ndev);
334         netif_start_queue(ndev);
335
336         list_for_each_entry_safe(peer, tmp, &rionet_peers, node) {
337                 if (!(peer->res = rio_request_outb_dbell(peer->rdev,
338                                                          RIONET_DOORBELL_JOIN,
339                                                          RIONET_DOORBELL_LEAVE)))
340                 {
341                         printk(KERN_ERR "%s: error requesting doorbells\n",
342                                DRV_NAME);
343                         continue;
344                 }
345
346                 /*
347                  * If device has initialized inbound doorbells,
348                  * send a join message
349                  */
350                 rio_read_config_32(peer->rdev, RIO_WRITE_PORT_CSR, &pwdcsr);
351                 if (pwdcsr & RIO_DOORBELL_AVAIL)
352                         rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
353         }
354
355       out:
356         return rc;
357 }
358
359 static int rionet_close(struct net_device *ndev)
360 {
361         struct rionet_private *rnet = (struct rionet_private *)ndev->priv;
362         struct rionet_peer *peer, *tmp;
363         int i;
364
365         if (netif_msg_ifup(rnet))
366                 printk(KERN_INFO "%s: close\n", DRV_NAME);
367
368         netif_stop_queue(ndev);
369         netif_carrier_off(ndev);
370
371         for (i = 0; i < RIONET_RX_RING_SIZE; i++)
372                 if (rnet->rx_skb[i])
373                         kfree_skb(rnet->rx_skb[i]);
374
375         list_for_each_entry_safe(peer, tmp, &rionet_peers, node) {
376                 if (rionet_active[peer->rdev->destid]) {
377                         rio_send_doorbell(peer->rdev, RIONET_DOORBELL_LEAVE);
378                         rionet_active[peer->rdev->destid] = NULL;
379                 }
380                 rio_release_outb_dbell(peer->rdev, peer->res);
381         }
382
383         rio_release_inb_dbell(rnet->mport, RIONET_DOORBELL_JOIN,
384                               RIONET_DOORBELL_LEAVE);
385         rio_release_inb_mbox(rnet->mport, RIONET_MAILBOX);
386         rio_release_outb_mbox(rnet->mport, RIONET_MAILBOX);
387
388         return 0;
389 }
390
391 static void rionet_remove(struct rio_dev *rdev)
392 {
393         struct net_device *ndev = NULL;
394         struct rionet_peer *peer, *tmp;
395
396         unregister_netdev(ndev);
397         kfree(ndev);
398
399         list_for_each_entry_safe(peer, tmp, &rionet_peers, node) {
400                 list_del(&peer->node);
401                 kfree(peer);
402         }
403 }
404
405 static void rionet_get_drvinfo(struct net_device *ndev,
406                                struct ethtool_drvinfo *info)
407 {
408         struct rionet_private *rnet = ndev->priv;
409
410         strcpy(info->driver, DRV_NAME);
411         strcpy(info->version, DRV_VERSION);
412         strcpy(info->fw_version, "n/a");
413         strcpy(info->bus_info, rnet->mport->name);
414 }
415
416 static u32 rionet_get_msglevel(struct net_device *ndev)
417 {
418         struct rionet_private *rnet = ndev->priv;
419
420         return rnet->msg_enable;
421 }
422
423 static void rionet_set_msglevel(struct net_device *ndev, u32 value)
424 {
425         struct rionet_private *rnet = ndev->priv;
426
427         rnet->msg_enable = value;
428 }
429
430 static const struct ethtool_ops rionet_ethtool_ops = {
431         .get_drvinfo = rionet_get_drvinfo,
432         .get_msglevel = rionet_get_msglevel,
433         .set_msglevel = rionet_set_msglevel,
434         .get_link = ethtool_op_get_link,
435 };
436
437 static int rionet_setup_netdev(struct rio_mport *mport)
438 {
439         int rc = 0;
440         struct net_device *ndev = NULL;
441         struct rionet_private *rnet;
442         u16 device_id;
443
444         /* Allocate our net_device structure */
445         ndev = alloc_etherdev(sizeof(struct rionet_private));
446         if (ndev == NULL) {
447                 printk(KERN_INFO "%s: could not allocate ethernet device.\n",
448                        DRV_NAME);
449                 rc = -ENOMEM;
450                 goto out;
451         }
452
453         /* Set up private area */
454         rnet = (struct rionet_private *)ndev->priv;
455         rnet->mport = mport;
456
457         /* Set the default MAC address */
458         device_id = rio_local_get_device_id(mport);
459         ndev->dev_addr[0] = 0x00;
460         ndev->dev_addr[1] = 0x01;
461         ndev->dev_addr[2] = 0x00;
462         ndev->dev_addr[3] = 0x01;
463         ndev->dev_addr[4] = device_id >> 8;
464         ndev->dev_addr[5] = device_id & 0xff;
465
466         /* Fill in the driver function table */
467         ndev->open = &rionet_open;
468         ndev->hard_start_xmit = &rionet_start_xmit;
469         ndev->stop = &rionet_close;
470         ndev->get_stats = &rionet_stats;
471         ndev->mtu = RIO_MAX_MSG_SIZE - 14;
472         ndev->features = NETIF_F_LLTX;
473         SET_ETHTOOL_OPS(ndev, &rionet_ethtool_ops);
474
475         SET_MODULE_OWNER(ndev);
476
477         spin_lock_init(&rnet->lock);
478         spin_lock_init(&rnet->tx_lock);
479
480         rnet->msg_enable = RIONET_DEFAULT_MSGLEVEL;
481
482         rc = register_netdev(ndev);
483         if (rc != 0)
484                 goto out;
485
486         printk("%s: %s %s Version %s, MAC %02x:%02x:%02x:%02x:%02x:%02x\n",
487                ndev->name,
488                DRV_NAME,
489                DRV_DESC,
490                DRV_VERSION,
491                ndev->dev_addr[0], ndev->dev_addr[1], ndev->dev_addr[2],
492                ndev->dev_addr[3], ndev->dev_addr[4], ndev->dev_addr[5]);
493
494       out:
495         return rc;
496 }
497
498 /*
499  * XXX Make multi-net safe
500  */
501 static int rionet_probe(struct rio_dev *rdev, const struct rio_device_id *id)
502 {
503         int rc = -ENODEV;
504         u32 lpef, lsrc_ops, ldst_ops;
505         struct rionet_peer *peer;
506
507         /* If local device is not rionet capable, give up quickly */
508         if (!rionet_capable)
509                 goto out;
510
511         /*
512          * First time through, make sure local device is rionet
513          * capable, setup netdev,  and set flags so this is skipped
514          * on later probes
515          */
516         if (!rionet_check) {
517                 rio_local_read_config_32(rdev->net->hport, RIO_PEF_CAR, &lpef);
518                 rio_local_read_config_32(rdev->net->hport, RIO_SRC_OPS_CAR,
519                                          &lsrc_ops);
520                 rio_local_read_config_32(rdev->net->hport, RIO_DST_OPS_CAR,
521                                          &ldst_ops);
522                 if (!is_rionet_capable(lpef, lsrc_ops, ldst_ops)) {
523                         printk(KERN_ERR
524                                "%s: local device is not network capable\n",
525                                DRV_NAME);
526                         rionet_check = 1;
527                         rionet_capable = 0;
528                         goto out;
529                 }
530
531                 rc = rionet_setup_netdev(rdev->net->hport);
532                 rionet_check = 1;
533         }
534
535         /*
536          * If the remote device has mailbox/doorbell capabilities,
537          * add it to the peer list.
538          */
539         if (dev_rionet_capable(rdev)) {
540                 if (!(peer = kmalloc(sizeof(struct rionet_peer), GFP_KERNEL))) {
541                         rc = -ENOMEM;
542                         goto out;
543                 }
544                 peer->rdev = rdev;
545                 list_add_tail(&peer->node, &rionet_peers);
546         }
547
548       out:
549         return rc;
550 }
551
552 static struct rio_device_id rionet_id_table[] = {
553         {RIO_DEVICE(RIO_ANY_ID, RIO_ANY_ID)}
554 };
555
556 static struct rio_driver rionet_driver = {
557         .name = "rionet",
558         .id_table = rionet_id_table,
559         .probe = rionet_probe,
560         .remove = rionet_remove,
561 };
562
563 static int __init rionet_init(void)
564 {
565         return rio_register_driver(&rionet_driver);
566 }
567
568 static void __exit rionet_exit(void)
569 {
570         rio_unregister_driver(&rionet_driver);
571 }
572
573 module_init(rionet_init);
574 module_exit(rionet_exit);