ppp: Don't stop and restart queue on every TX packet
[pandora-kernel.git] / 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/slab.h>
20 #include <linux/rio_ids.h>
21
22 #include <linux/netdevice.h>
23 #include <linux/etherdevice.h>
24 #include <linux/skbuff.h>
25 #include <linux/crc32.h>
26 #include <linux/ethtool.h>
27
28 #define DRV_NAME        "rionet"
29 #define DRV_VERSION     "0.2"
30 #define DRV_AUTHOR      "Matt Porter <mporter@kernel.crashing.org>"
31 #define DRV_DESC        "Ethernet over RapidIO"
32
33 MODULE_AUTHOR(DRV_AUTHOR);
34 MODULE_DESCRIPTION(DRV_DESC);
35 MODULE_LICENSE("GPL");
36
37 #define RIONET_DEFAULT_MSGLEVEL \
38                         (NETIF_MSG_DRV          | \
39                          NETIF_MSG_LINK         | \
40                          NETIF_MSG_RX_ERR       | \
41                          NETIF_MSG_TX_ERR)
42
43 #define RIONET_DOORBELL_JOIN    0x1000
44 #define RIONET_DOORBELL_LEAVE   0x1001
45
46 #define RIONET_MAILBOX          0
47
48 #define RIONET_TX_RING_SIZE     CONFIG_RIONET_TX_SIZE
49 #define RIONET_RX_RING_SIZE     CONFIG_RIONET_RX_SIZE
50
51 static LIST_HEAD(rionet_peers);
52
53 struct rionet_private {
54         struct rio_mport *mport;
55         struct sk_buff *rx_skb[RIONET_RX_RING_SIZE];
56         struct sk_buff *tx_skb[RIONET_TX_RING_SIZE];
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 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;
82
83 #define is_rionet_capable(src_ops, dst_ops)                     \
84                         ((src_ops & RIO_SRC_OPS_DATA_MSG) &&    \
85                          (dst_ops & RIO_DST_OPS_DATA_MSG) &&    \
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->src_ops, dev->dst_ops)
90
91 #define RIONET_MAC_MATCH(x)     (!memcmp((x), "\00\01\00\01", 4))
92 #define RIONET_GET_DESTID(x)    ((*((u8 *)x + 4) << 8) | *((u8 *)x + 5))
93
94 static int rionet_rx_clean(struct net_device *ndev)
95 {
96         int i;
97         int error = 0;
98         struct rionet_private *rnet = netdev_priv(ndev);
99         void *data;
100
101         i = rnet->rx_slot;
102
103         do {
104                 if (!rnet->rx_skb[i])
105                         continue;
106
107                 if (!(data = rio_get_inb_message(rnet->mport, RIONET_MAILBOX)))
108                         break;
109
110                 rnet->rx_skb[i]->data = data;
111                 skb_put(rnet->rx_skb[i], RIO_MAX_MSG_SIZE);
112                 rnet->rx_skb[i]->protocol =
113                     eth_type_trans(rnet->rx_skb[i], ndev);
114                 error = netif_rx(rnet->rx_skb[i]);
115
116                 if (error == NET_RX_DROP) {
117                         ndev->stats.rx_dropped++;
118                 } else {
119                         ndev->stats.rx_packets++;
120                         ndev->stats.rx_bytes += RIO_MAX_MSG_SIZE;
121                 }
122
123         } while ((i = (i + 1) % RIONET_RX_RING_SIZE) != rnet->rx_slot);
124
125         return i;
126 }
127
128 static void rionet_rx_fill(struct net_device *ndev, int end)
129 {
130         int i;
131         struct rionet_private *rnet = netdev_priv(ndev);
132
133         i = rnet->rx_slot;
134         do {
135                 rnet->rx_skb[i] = dev_alloc_skb(RIO_MAX_MSG_SIZE);
136
137                 if (!rnet->rx_skb[i])
138                         break;
139
140                 rio_add_inb_buffer(rnet->mport, RIONET_MAILBOX,
141                                    rnet->rx_skb[i]->data);
142         } while ((i = (i + 1) % RIONET_RX_RING_SIZE) != end);
143
144         rnet->rx_slot = i;
145 }
146
147 static int rionet_queue_tx_msg(struct sk_buff *skb, struct net_device *ndev,
148                                struct rio_dev *rdev)
149 {
150         struct rionet_private *rnet = netdev_priv(ndev);
151
152         rio_add_outb_message(rnet->mport, rdev, 0, skb->data, skb->len);
153         rnet->tx_skb[rnet->tx_slot] = skb;
154
155         ndev->stats.tx_packets++;
156         ndev->stats.tx_bytes += skb->len;
157
158         if (++rnet->tx_cnt == RIONET_TX_RING_SIZE)
159                 netif_stop_queue(ndev);
160
161         ++rnet->tx_slot;
162         rnet->tx_slot &= (RIONET_TX_RING_SIZE - 1);
163
164         if (netif_msg_tx_queued(rnet))
165                 printk(KERN_INFO "%s: queued skb len %8.8x\n", DRV_NAME,
166                        skb->len);
167
168         return 0;
169 }
170
171 static int rionet_start_xmit(struct sk_buff *skb, struct net_device *ndev)
172 {
173         int i;
174         struct rionet_private *rnet = netdev_priv(ndev);
175         struct ethhdr *eth = (struct ethhdr *)skb->data;
176         u16 destid;
177         unsigned long flags;
178
179         local_irq_save(flags);
180         if (!spin_trylock(&rnet->tx_lock)) {
181                 local_irq_restore(flags);
182                 return NETDEV_TX_LOCKED;
183         }
184
185         if ((rnet->tx_cnt + 1) > RIONET_TX_RING_SIZE) {
186                 netif_stop_queue(ndev);
187                 spin_unlock_irqrestore(&rnet->tx_lock, flags);
188                 printk(KERN_ERR "%s: BUG! Tx Ring full when queue awake!\n",
189                        ndev->name);
190                 return NETDEV_TX_BUSY;
191         }
192
193         if (is_multicast_ether_addr(eth->h_dest)) {
194                 for (i = 0; i < RIO_MAX_ROUTE_ENTRIES(rnet->mport->sys_size);
195                                 i++)
196                         if (rionet_active[i])
197                                 rionet_queue_tx_msg(skb, ndev,
198                                                     rionet_active[i]);
199         } else if (RIONET_MAC_MATCH(eth->h_dest)) {
200                 destid = RIONET_GET_DESTID(eth->h_dest);
201                 if (rionet_active[destid])
202                         rionet_queue_tx_msg(skb, ndev, rionet_active[destid]);
203         }
204
205         spin_unlock_irqrestore(&rnet->tx_lock, flags);
206
207         return NETDEV_TX_OK;
208 }
209
210 static void rionet_dbell_event(struct rio_mport *mport, void *dev_id, u16 sid, u16 tid,
211                                u16 info)
212 {
213         struct net_device *ndev = dev_id;
214         struct rionet_private *rnet = netdev_priv(ndev);
215         struct rionet_peer *peer;
216
217         if (netif_msg_intr(rnet))
218                 printk(KERN_INFO "%s: doorbell sid %4.4x tid %4.4x info %4.4x",
219                        DRV_NAME, sid, tid, info);
220         if (info == RIONET_DOORBELL_JOIN) {
221                 if (!rionet_active[sid]) {
222                         list_for_each_entry(peer, &rionet_peers, node) {
223                                 if (peer->rdev->destid == sid)
224                                         rionet_active[sid] = peer->rdev;
225                         }
226                         rio_mport_send_doorbell(mport, sid,
227                                                 RIONET_DOORBELL_JOIN);
228                 }
229         } else if (info == RIONET_DOORBELL_LEAVE) {
230                 rionet_active[sid] = NULL;
231         } else {
232                 if (netif_msg_intr(rnet))
233                         printk(KERN_WARNING "%s: unhandled doorbell\n",
234                                DRV_NAME);
235         }
236 }
237
238 static void rionet_inb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
239 {
240         int n;
241         struct net_device *ndev = dev_id;
242         struct rionet_private *rnet = netdev_priv(ndev);
243
244         if (netif_msg_intr(rnet))
245                 printk(KERN_INFO "%s: inbound message event, mbox %d slot %d\n",
246                        DRV_NAME, mbox, slot);
247
248         spin_lock(&rnet->lock);
249         if ((n = rionet_rx_clean(ndev)) != rnet->rx_slot)
250                 rionet_rx_fill(ndev, n);
251         spin_unlock(&rnet->lock);
252 }
253
254 static void rionet_outb_msg_event(struct rio_mport *mport, void *dev_id, int mbox, int slot)
255 {
256         struct net_device *ndev = dev_id;
257         struct rionet_private *rnet = netdev_priv(ndev);
258
259         spin_lock(&rnet->lock);
260
261         if (netif_msg_intr(rnet))
262                 printk(KERN_INFO
263                        "%s: outbound message event, mbox %d slot %d\n",
264                        DRV_NAME, mbox, slot);
265
266         while (rnet->tx_cnt && (rnet->ack_slot != slot)) {
267                 /* dma unmap single */
268                 dev_kfree_skb_irq(rnet->tx_skb[rnet->ack_slot]);
269                 rnet->tx_skb[rnet->ack_slot] = NULL;
270                 ++rnet->ack_slot;
271                 rnet->ack_slot &= (RIONET_TX_RING_SIZE - 1);
272                 rnet->tx_cnt--;
273         }
274
275         if (rnet->tx_cnt < RIONET_TX_RING_SIZE)
276                 netif_wake_queue(ndev);
277
278         spin_unlock(&rnet->lock);
279 }
280
281 static int rionet_open(struct net_device *ndev)
282 {
283         int i, rc = 0;
284         struct rionet_peer *peer, *tmp;
285         struct rionet_private *rnet = netdev_priv(ndev);
286
287         if (netif_msg_ifup(rnet))
288                 printk(KERN_INFO "%s: open\n", DRV_NAME);
289
290         if ((rc = rio_request_inb_dbell(rnet->mport,
291                                         (void *)ndev,
292                                         RIONET_DOORBELL_JOIN,
293                                         RIONET_DOORBELL_LEAVE,
294                                         rionet_dbell_event)) < 0)
295                 goto out;
296
297         if ((rc = rio_request_inb_mbox(rnet->mport,
298                                        (void *)ndev,
299                                        RIONET_MAILBOX,
300                                        RIONET_RX_RING_SIZE,
301                                        rionet_inb_msg_event)) < 0)
302                 goto out;
303
304         if ((rc = rio_request_outb_mbox(rnet->mport,
305                                         (void *)ndev,
306                                         RIONET_MAILBOX,
307                                         RIONET_TX_RING_SIZE,
308                                         rionet_outb_msg_event)) < 0)
309                 goto out;
310
311         /* Initialize inbound message ring */
312         for (i = 0; i < RIONET_RX_RING_SIZE; i++)
313                 rnet->rx_skb[i] = NULL;
314         rnet->rx_slot = 0;
315         rionet_rx_fill(ndev, 0);
316
317         rnet->tx_slot = 0;
318         rnet->tx_cnt = 0;
319         rnet->ack_slot = 0;
320
321         netif_carrier_on(ndev);
322         netif_start_queue(ndev);
323
324         list_for_each_entry_safe(peer, tmp, &rionet_peers, node) {
325                 if (!(peer->res = rio_request_outb_dbell(peer->rdev,
326                                                          RIONET_DOORBELL_JOIN,
327                                                          RIONET_DOORBELL_LEAVE)))
328                 {
329                         printk(KERN_ERR "%s: error requesting doorbells\n",
330                                DRV_NAME);
331                         continue;
332                 }
333
334                 /* Send a join message */
335                 rio_send_doorbell(peer->rdev, RIONET_DOORBELL_JOIN);
336         }
337
338       out:
339         return rc;
340 }
341
342 static int rionet_close(struct net_device *ndev)
343 {
344         struct rionet_private *rnet = netdev_priv(ndev);
345         struct rionet_peer *peer, *tmp;
346         int i;
347
348         if (netif_msg_ifup(rnet))
349                 printk(KERN_INFO "%s: close\n", DRV_NAME);
350
351         netif_stop_queue(ndev);
352         netif_carrier_off(ndev);
353
354         for (i = 0; i < RIONET_RX_RING_SIZE; i++)
355                 kfree_skb(rnet->rx_skb[i]);
356
357         list_for_each_entry_safe(peer, tmp, &rionet_peers, node) {
358                 if (rionet_active[peer->rdev->destid]) {
359                         rio_send_doorbell(peer->rdev, RIONET_DOORBELL_LEAVE);
360                         rionet_active[peer->rdev->destid] = NULL;
361                 }
362                 rio_release_outb_dbell(peer->rdev, peer->res);
363         }
364
365         rio_release_inb_dbell(rnet->mport, RIONET_DOORBELL_JOIN,
366                               RIONET_DOORBELL_LEAVE);
367         rio_release_inb_mbox(rnet->mport, RIONET_MAILBOX);
368         rio_release_outb_mbox(rnet->mport, RIONET_MAILBOX);
369
370         return 0;
371 }
372
373 static void rionet_remove(struct rio_dev *rdev)
374 {
375         struct net_device *ndev = rio_get_drvdata(rdev);
376         struct rionet_peer *peer, *tmp;
377
378         free_pages((unsigned long)rionet_active, rdev->net->hport->sys_size ?
379                                         __fls(sizeof(void *)) + 4 : 0);
380         unregister_netdev(ndev);
381         free_netdev(ndev);
382
383         list_for_each_entry_safe(peer, tmp, &rionet_peers, node) {
384                 list_del(&peer->node);
385                 kfree(peer);
386         }
387 }
388
389 static void rionet_get_drvinfo(struct net_device *ndev,
390                                struct ethtool_drvinfo *info)
391 {
392         struct rionet_private *rnet = netdev_priv(ndev);
393
394         strcpy(info->driver, DRV_NAME);
395         strcpy(info->version, DRV_VERSION);
396         strcpy(info->fw_version, "n/a");
397         strcpy(info->bus_info, rnet->mport->name);
398 }
399
400 static u32 rionet_get_msglevel(struct net_device *ndev)
401 {
402         struct rionet_private *rnet = netdev_priv(ndev);
403
404         return rnet->msg_enable;
405 }
406
407 static void rionet_set_msglevel(struct net_device *ndev, u32 value)
408 {
409         struct rionet_private *rnet = netdev_priv(ndev);
410
411         rnet->msg_enable = value;
412 }
413
414 static const struct ethtool_ops rionet_ethtool_ops = {
415         .get_drvinfo = rionet_get_drvinfo,
416         .get_msglevel = rionet_get_msglevel,
417         .set_msglevel = rionet_set_msglevel,
418         .get_link = ethtool_op_get_link,
419 };
420
421 static const struct net_device_ops rionet_netdev_ops = {
422         .ndo_open               = rionet_open,
423         .ndo_stop               = rionet_close,
424         .ndo_start_xmit         = rionet_start_xmit,
425         .ndo_change_mtu         = eth_change_mtu,
426         .ndo_validate_addr      = eth_validate_addr,
427         .ndo_set_mac_address    = eth_mac_addr,
428 };
429
430 static int rionet_setup_netdev(struct rio_mport *mport, struct net_device *ndev)
431 {
432         int rc = 0;
433         struct rionet_private *rnet;
434         u16 device_id;
435
436         rionet_active = (struct rio_dev **)__get_free_pages(GFP_KERNEL,
437                         mport->sys_size ? __fls(sizeof(void *)) + 4 : 0);
438         if (!rionet_active) {
439                 rc = -ENOMEM;
440                 goto out;
441         }
442         memset((void *)rionet_active, 0, sizeof(void *) *
443                                 RIO_MAX_ROUTE_ENTRIES(mport->sys_size));
444
445         /* Set up private area */
446         rnet = netdev_priv(ndev);
447         rnet->mport = mport;
448
449         /* Set the default MAC address */
450         device_id = rio_local_get_device_id(mport);
451         ndev->dev_addr[0] = 0x00;
452         ndev->dev_addr[1] = 0x01;
453         ndev->dev_addr[2] = 0x00;
454         ndev->dev_addr[3] = 0x01;
455         ndev->dev_addr[4] = device_id >> 8;
456         ndev->dev_addr[5] = device_id & 0xff;
457
458         ndev->netdev_ops = &rionet_netdev_ops;
459         ndev->mtu = RIO_MAX_MSG_SIZE - 14;
460         ndev->features = NETIF_F_LLTX;
461         SET_ETHTOOL_OPS(ndev, &rionet_ethtool_ops);
462
463         spin_lock_init(&rnet->lock);
464         spin_lock_init(&rnet->tx_lock);
465
466         rnet->msg_enable = RIONET_DEFAULT_MSGLEVEL;
467
468         rc = register_netdev(ndev);
469         if (rc != 0)
470                 goto out;
471
472         printk("%s: %s %s Version %s, MAC %pM\n",
473                ndev->name,
474                DRV_NAME,
475                DRV_DESC,
476                DRV_VERSION,
477                ndev->dev_addr);
478
479       out:
480         return rc;
481 }
482
483 /*
484  * XXX Make multi-net safe
485  */
486 static int rionet_probe(struct rio_dev *rdev, const struct rio_device_id *id)
487 {
488         int rc = -ENODEV;
489         u32 lsrc_ops, ldst_ops;
490         struct rionet_peer *peer;
491         struct net_device *ndev = NULL;
492
493         /* If local device is not rionet capable, give up quickly */
494         if (!rionet_capable)
495                 goto out;
496
497         /* Allocate our net_device structure */
498         ndev = alloc_etherdev(sizeof(struct rionet_private));
499         if (ndev == NULL) {
500                 printk(KERN_INFO "%s: could not allocate ethernet device.\n",
501                        DRV_NAME);
502                 rc = -ENOMEM;
503                 goto out;
504         }
505
506         /*
507          * First time through, make sure local device is rionet
508          * capable, setup netdev,  and set flags so this is skipped
509          * on later probes
510          */
511         if (!rionet_check) {
512                 rio_local_read_config_32(rdev->net->hport, RIO_SRC_OPS_CAR,
513                                          &lsrc_ops);
514                 rio_local_read_config_32(rdev->net->hport, RIO_DST_OPS_CAR,
515                                          &ldst_ops);
516                 if (!is_rionet_capable(lsrc_ops, ldst_ops)) {
517                         printk(KERN_ERR
518                                "%s: local device is not network capable\n",
519                                DRV_NAME);
520                         rionet_check = 1;
521                         rionet_capable = 0;
522                         goto out;
523                 }
524
525                 rc = rionet_setup_netdev(rdev->net->hport, ndev);
526                 rionet_check = 1;
527         }
528
529         /*
530          * If the remote device has mailbox/doorbell capabilities,
531          * add it to the peer list.
532          */
533         if (dev_rionet_capable(rdev)) {
534                 if (!(peer = kmalloc(sizeof(struct rionet_peer), GFP_KERNEL))) {
535                         rc = -ENOMEM;
536                         goto out;
537                 }
538                 peer->rdev = rdev;
539                 list_add_tail(&peer->node, &rionet_peers);
540         }
541
542         rio_set_drvdata(rdev, ndev);
543
544       out:
545         return rc;
546 }
547
548 static struct rio_device_id rionet_id_table[] = {
549         {RIO_DEVICE(RIO_ANY_ID, RIO_ANY_ID)}
550 };
551
552 static struct rio_driver rionet_driver = {
553         .name = "rionet",
554         .id_table = rionet_id_table,
555         .probe = rionet_probe,
556         .remove = rionet_remove,
557 };
558
559 static int __init rionet_init(void)
560 {
561         return rio_register_driver(&rionet_driver);
562 }
563
564 static void __exit rionet_exit(void)
565 {
566         rio_unregister_driver(&rionet_driver);
567 }
568
569 late_initcall(rionet_init);
570 module_exit(rionet_exit);