hopefully fixes dma issues seen on ethernet driver when under high load
[lede.git] / target / linux / ramips / files / drivers / net / ramips.c
1 /*
2  *   This program is free software; you can redistribute it and/or modify
3  *   it under the terms of the GNU General Public License as published by
4  *   the Free Software Foundation; version 2 of the License
5  *
6  *   This program is distributed in the hope that it will be useful,
7  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
8  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9  *   GNU General Public License for more details.
10  *
11  *   You should have received a copy of the GNU General Public License
12  *   along with this program; if not, write to the Free Software
13  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
14  *
15  *   Copyright (C) 2009 John Crispin <blogic@openwrt.org>
16  */
17
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/types.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/init.h>
23 #include <linux/skbuff.h>
24 #include <linux/etherdevice.h>
25 #include <linux/platform_device.h>
26
27 #include <ramips_eth_platform.h>
28 #include "ramips_eth.h"
29
30 #define TX_TIMEOUT (20 * HZ / 100)
31 #define MAX_RX_LENGTH   1500
32
33 #ifdef CONFIG_RALINK_RT305X
34 #include "ramips_esw.c"
35 #endif
36
37 #define phys_to_bus(a)  (a & 0x1FFFFFFF)
38
39 static struct net_device * ramips_dev;
40 static void __iomem *ramips_fe_base = 0;
41
42 static inline void
43 ramips_fe_wr(u32 val, unsigned reg)
44 {
45         __raw_writel(val, ramips_fe_base + reg);
46 }
47
48 static inline u32
49 ramips_fe_rr(unsigned reg)
50 {
51         return __raw_readl(ramips_fe_base + reg);
52 }
53
54 static void
55 ramips_cleanup_dma(struct net_device *dev)
56 {
57         struct raeth_priv *priv = netdev_priv(dev);
58         int i;
59
60         for (i = 0; i < NUM_RX_DESC; i++)
61                 if (priv->rx_skb[i])
62                         dev_kfree_skb_any(priv->rx_skb[i]);
63
64         if (priv->rx)
65                 dma_free_coherent(NULL,
66                                   NUM_RX_DESC * sizeof(struct ramips_rx_dma),
67                                   priv->rx, priv->phy_rx);
68
69         if (priv->tx)
70                 dma_free_coherent(NULL,
71                                   NUM_TX_DESC * sizeof(struct ramips_tx_dma),
72                                   priv->tx, priv->phy_tx);
73 }
74
75 static int
76 ramips_alloc_dma(struct net_device *dev)
77 {
78         struct raeth_priv *priv = netdev_priv(dev);
79         int err = -ENOMEM;
80         int i;
81
82         priv->skb_free_idx = 0;
83
84         /* setup tx ring */
85         priv->tx = dma_alloc_coherent(NULL,
86                 NUM_TX_DESC * sizeof(struct ramips_tx_dma), &priv->phy_tx, GFP_ATOMIC);
87         if (!priv->tx)
88                 goto err_cleanup;
89
90         for(i = 0; i < NUM_TX_DESC; i++)
91         {
92                 memset(&priv->tx[i], 0, sizeof(struct ramips_tx_dma));
93                 priv->tx[i].txd2 |= TX_DMA_LSO | TX_DMA_DONE;
94                 priv->tx[i].txd4 &= (TX_DMA_QN_MASK | TX_DMA_PN_MASK);
95                 priv->tx[i].txd4 |= TX_DMA_QN(3) | TX_DMA_PN(1);
96         }
97
98         /* setup rx ring */
99         priv->rx = dma_alloc_coherent(NULL,
100                 NUM_RX_DESC * sizeof(struct ramips_rx_dma), &priv->phy_rx, GFP_ATOMIC);
101         if (!priv->rx)
102                 goto err_cleanup;
103
104         memset(priv->rx, 0, sizeof(struct ramips_rx_dma) * NUM_RX_DESC);
105         for(i = 0; i < NUM_RX_DESC; i++)
106         {
107                 struct sk_buff *new_skb = dev_alloc_skb(MAX_RX_LENGTH + 2);
108
109                 if (!new_skb)
110                         goto err_cleanup;
111
112                 skb_reserve(new_skb, 2);
113                 priv->rx[i].rxd1 =
114                         dma_map_single(NULL, skb_put(new_skb, 2), MAX_RX_LENGTH + 2,
115                                 DMA_FROM_DEVICE);
116                 priv->rx[i].rxd2 |= RX_DMA_LSO;
117                 priv->rx_skb[i] = new_skb;
118         }
119
120         return 0;
121
122  err_cleanup:
123         ramips_cleanup_dma(dev);
124         return err;
125 }
126
127 static void
128 ramips_setup_dma(struct net_device *dev)
129 {
130         struct raeth_priv *priv = netdev_priv(dev);
131
132         ramips_fe_wr(phys_to_bus(priv->phy_tx), RAMIPS_TX_BASE_PTR0);
133         ramips_fe_wr(NUM_TX_DESC, RAMIPS_TX_MAX_CNT0);
134         ramips_fe_wr(0, RAMIPS_TX_CTX_IDX0);
135         ramips_fe_wr(RAMIPS_PST_DTX_IDX0, RAMIPS_PDMA_RST_CFG);
136
137         ramips_fe_wr(phys_to_bus(priv->phy_rx), RAMIPS_RX_BASE_PTR0);
138         ramips_fe_wr(NUM_RX_DESC, RAMIPS_RX_MAX_CNT0);
139         ramips_fe_wr((NUM_RX_DESC - 1), RAMIPS_RX_CALC_IDX0);
140         ramips_fe_wr(RAMIPS_PST_DRX_IDX0, RAMIPS_PDMA_RST_CFG);
141 }
142
143 static int
144 ramips_eth_hard_start_xmit(struct sk_buff* skb, struct net_device *dev)
145 {
146         struct raeth_priv *priv = netdev_priv(dev);
147         unsigned long tx;
148         unsigned int tx_next;
149         unsigned int mapped_addr;
150
151
152         if(priv->plat->min_pkt_len)
153         {
154                 if(skb->len < priv->plat->min_pkt_len)
155                  {
156                      if(skb_padto(skb, priv->plat->min_pkt_len))
157                          {
158                                  printk(KERN_ERR "ramips_eth: skb_padto failed\n");
159                                  kfree_skb(skb);
160                                  return 0;
161                          }
162                      skb_put(skb, priv->plat->min_pkt_len - skb->len);
163                  }
164         }
165         dev->trans_start = jiffies;
166         mapped_addr = (unsigned int)dma_map_single(NULL, skb->data, skb->len,
167                         DMA_TO_DEVICE);
168         dma_sync_single_for_device(NULL, mapped_addr, skb->len, DMA_TO_DEVICE);
169         tx = ramips_fe_rr(RAMIPS_TX_CTX_IDX0);
170         if(tx == NUM_TX_DESC - 1)
171                 tx_next = 0;
172         else
173                 tx_next = tx + 1;
174         if((priv->tx_skb[tx] == 0) && (priv->tx_skb[tx_next] == 0))
175         {
176                 if(!(priv->tx[tx].txd2 & TX_DMA_DONE) || !(priv->tx[tx_next].txd2 & TX_DMA_DONE))
177                 {
178                         kfree_skb(skb);
179                         dev->stats.tx_dropped++;
180                         printk(KERN_ERR "%s: dropping\n", dev->name);
181                         return 0;
182                 }
183                 priv->tx[tx].txd1 = virt_to_phys(skb->data);
184                 priv->tx[tx].txd2 &= ~(TX_DMA_PLEN0_MASK | TX_DMA_DONE);
185                 priv->tx[tx].txd2 |= TX_DMA_PLEN0(skb->len);
186                 wmb();
187                 ramips_fe_wr((tx + 1) % NUM_TX_DESC, RAMIPS_TX_CTX_IDX0);
188                 dev->stats.tx_packets++;
189                 dev->stats.tx_bytes += skb->len;
190                 priv->tx_skb[tx] = skb;
191                 wmb();
192                 ramips_fe_wr((tx + 1) % NUM_TX_DESC, RAMIPS_TX_CTX_IDX0);
193         } else {
194                 dev->stats.tx_dropped++;
195                 kfree_skb(skb);
196         }
197         return 0;
198 }
199
200 static void
201 ramips_eth_rx_hw(unsigned long ptr)
202 {
203         struct net_device *dev = (struct net_device*)ptr;
204         struct raeth_priv *priv = netdev_priv(dev);
205         int rx;
206         int max_rx = 16;
207
208         while(max_rx)
209         {
210                 struct sk_buff *rx_skb, *new_skb;
211
212                 rx = (ramips_fe_rr(RAMIPS_RX_CALC_IDX0) + 1) % NUM_RX_DESC;
213                 if(!(priv->rx[rx].rxd2 & RX_DMA_DONE))
214                         break;
215                 max_rx--;
216
217                 rx_skb = priv->rx_skb[rx];
218                 rx_skb->len = RX_DMA_PLEN0(priv->rx[rx].rxd2);
219                 rx_skb->tail = rx_skb->data + rx_skb->len;
220                 rx_skb->dev = dev;
221                 rx_skb->protocol = eth_type_trans(rx_skb, dev);
222                 rx_skb->ip_summed = CHECKSUM_NONE;
223                 dev->stats.rx_packets++;
224                 dev->stats.rx_bytes += rx_skb->len;
225                 netif_rx(rx_skb);
226
227                 new_skb = __dev_alloc_skb(MAX_RX_LENGTH + 2, GFP_DMA | GFP_ATOMIC);
228                 priv->rx_skb[rx] = new_skb;
229                 BUG_ON(!new_skb);
230                 skb_reserve(new_skb, 2);
231                 priv->rx[rx].rxd1 =
232                         dma_map_single(NULL, new_skb->data, MAX_RX_LENGTH + 2,
233                         DMA_FROM_DEVICE);
234                 priv->rx[rx].rxd2 &= ~RX_DMA_DONE;
235                 wmb();
236                 ramips_fe_wr(rx, RAMIPS_RX_CALC_IDX0);
237         }
238         if(max_rx == 0)
239                 tasklet_schedule(&priv->rx_tasklet);
240         else
241                 ramips_fe_wr(ramips_fe_rr(RAMIPS_FE_INT_ENABLE) | RAMIPS_RX_DLY_INT,
242                         RAMIPS_FE_INT_ENABLE);
243 }
244
245 static void
246 ramips_eth_tx_housekeeping(unsigned long ptr)
247 {
248         struct net_device *dev = (struct net_device*)ptr;
249         struct raeth_priv *priv = netdev_priv(dev);
250
251         while((priv->tx[priv->skb_free_idx].txd2 & TX_DMA_DONE) &&
252                 (priv->tx_skb[priv->skb_free_idx]))
253         {
254                 dev_kfree_skb_irq((struct sk_buff*)priv->tx_skb[priv->skb_free_idx]);
255                 priv->tx_skb[priv->skb_free_idx] = 0;
256                 priv->skb_free_idx++;
257                 if(priv->skb_free_idx >= NUM_TX_DESC)
258                         priv->skb_free_idx = 0;
259         }
260         ramips_fe_wr(ramips_fe_rr(RAMIPS_FE_INT_ENABLE) | RAMIPS_TX_DLY_INT,
261                 RAMIPS_FE_INT_ENABLE);
262 }
263
264 static int
265 ramips_eth_set_mac_addr(struct net_device *dev, void *priv)
266 {
267         unsigned char *mac = (unsigned char*)priv;
268
269         if(netif_running(dev))
270                 return -EBUSY;
271         memcpy(dev->dev_addr, ((struct sockaddr*)priv)->sa_data, dev->addr_len);
272         ramips_fe_wr((mac[0] << 8) | mac[1], RAMIPS_GDMA1_MAC_ADRH);
273         ramips_fe_wr(RAMIPS_GDMA1_MAC_ADRL,
274                 (mac[2] << 24) | (mac[3] << 16) | (mac[4] << 8) | mac[5]);
275         return 0;
276 }
277
278 static void
279 ramips_eth_timeout(struct net_device *dev)
280 {
281         struct raeth_priv *priv = netdev_priv(dev);
282
283         tasklet_schedule(&priv->tx_housekeeping_tasklet);
284 }
285
286 static irqreturn_t
287 ramips_eth_irq(int irq, void *dev)
288 {
289         struct raeth_priv *priv = netdev_priv(dev);
290         unsigned long fe_int = ramips_fe_rr(RAMIPS_FE_INT_STATUS);
291
292         ramips_fe_wr(0xFFFFFFFF, RAMIPS_FE_INT_STATUS);
293
294         if(fe_int & RAMIPS_RX_DLY_INT)
295         {
296                 ramips_fe_wr(ramips_fe_rr(RAMIPS_FE_INT_ENABLE) & ~(RAMIPS_RX_DLY_INT),
297                         RAMIPS_FE_INT_ENABLE);
298                 tasklet_schedule(&priv->rx_tasklet);
299         }
300         if(fe_int & RAMIPS_TX_DLY_INT)
301                 ramips_eth_tx_housekeeping((unsigned long)dev);
302         return IRQ_HANDLED;
303 }
304
305 static int
306 ramips_eth_open(struct net_device *dev)
307 {
308         struct raeth_priv *priv = netdev_priv(dev);
309         int err;
310
311         err = request_irq(dev->irq, ramips_eth_irq, IRQF_DISABLED,
312                           dev->name, dev);
313         if (err)
314                 return err;
315
316         err = ramips_alloc_dma(dev);
317         if (err)
318                 goto err_free_irq;
319
320         ramips_setup_dma(dev);
321         ramips_fe_wr((ramips_fe_rr(RAMIPS_PDMA_GLO_CFG) & 0xff) |
322                 (RAMIPS_TX_WB_DDONE | RAMIPS_RX_DMA_EN |
323                 RAMIPS_TX_DMA_EN | RAMIPS_PDMA_SIZE_4DWORDS),
324                 RAMIPS_PDMA_GLO_CFG);
325         ramips_fe_wr((ramips_fe_rr(RAMIPS_FE_GLO_CFG) &
326                 ~(RAMIPS_US_CYC_CNT_MASK << RAMIPS_US_CYC_CNT_SHIFT)) |
327                 ((rt305x_sys_freq / RAMIPS_US_CYC_CNT_DIVISOR) << RAMIPS_US_CYC_CNT_SHIFT),
328                 RAMIPS_FE_GLO_CFG);
329         tasklet_init(&priv->tx_housekeeping_tasklet, ramips_eth_tx_housekeeping,
330                 (unsigned long)dev);
331         tasklet_init(&priv->rx_tasklet, ramips_eth_rx_hw, (unsigned long)dev);
332         ramips_fe_wr(RAMIPS_DELAY_INIT, RAMIPS_DLY_INT_CFG);
333         ramips_fe_wr(RAMIPS_TX_DLY_INT | RAMIPS_RX_DLY_INT, RAMIPS_FE_INT_ENABLE);
334         ramips_fe_wr(ramips_fe_rr(RAMIPS_GDMA1_FWD_CFG) &
335                 ~(RAMIPS_GDM1_ICS_EN | RAMIPS_GDM1_TCS_EN | RAMIPS_GDM1_UCS_EN | 0xffff),
336                 RAMIPS_GDMA1_FWD_CFG);
337         ramips_fe_wr(ramips_fe_rr(RAMIPS_CDMA_CSG_CFG) &
338                 ~(RAMIPS_ICS_GEN_EN | RAMIPS_TCS_GEN_EN | RAMIPS_UCS_GEN_EN),
339                 RAMIPS_CDMA_CSG_CFG);
340         ramips_fe_wr(RAMIPS_PSE_FQFC_CFG_INIT, RAMIPS_PSE_FQ_CFG);
341         ramips_fe_wr(1, RAMIPS_FE_RST_GL);
342         ramips_fe_wr(0, RAMIPS_FE_RST_GL);
343         netif_start_queue(dev);
344         return 0;
345
346  err_free_irq:
347         free_irq(dev->irq, dev);
348         return err;
349 }
350
351 static int
352 ramips_eth_stop(struct net_device *dev)
353 {
354         struct raeth_priv *priv = netdev_priv(dev);
355
356         ramips_fe_wr(RAMIPS_PDMA_GLO_CFG, ramips_fe_rr(RAMIPS_PDMA_GLO_CFG) &
357                 ~(RAMIPS_TX_WB_DDONE | RAMIPS_RX_DMA_EN | RAMIPS_TX_DMA_EN));
358         free_irq(dev->irq, dev);
359         netif_stop_queue(dev);
360         tasklet_kill(&priv->tx_housekeeping_tasklet);
361         tasklet_kill(&priv->rx_tasklet);
362         ramips_cleanup_dma(dev);
363         printk(KERN_DEBUG "ramips_eth: stopped\n");
364         return 0;
365 }
366
367 static int __init
368 ramips_eth_probe(struct net_device *dev)
369 {
370         struct raeth_priv *priv = netdev_priv(dev);
371         struct sockaddr addr;
372
373         BUG_ON(!priv->plat->reset_fe);
374         priv->plat->reset_fe();
375         net_srandom(jiffies);
376         memcpy(addr.sa_data, priv->plat->mac, 6);
377         ramips_eth_set_mac_addr(dev, &addr);
378
379         ether_setup(dev);
380         dev->open = ramips_eth_open;
381         dev->stop = ramips_eth_stop;
382         dev->hard_start_xmit = ramips_eth_hard_start_xmit;
383         dev->set_mac_address = ramips_eth_set_mac_addr;
384         dev->mtu = MAX_RX_LENGTH;
385         dev->tx_timeout = ramips_eth_timeout;
386         dev->watchdog_timeo = TX_TIMEOUT;
387         return 0;
388 }
389
390 static int
391 ramips_eth_plat_probe(struct platform_device *plat)
392 {
393         struct raeth_priv *priv;
394         struct ramips_eth_platform_data *data = plat->dev.platform_data;
395         struct resource *res;
396         int err;
397
398         if (!data) {
399                 dev_err(&plat->dev, "no platform data specified\n");
400                 return -EINVAL;
401         }
402
403         res = platform_get_resource(plat, IORESOURCE_MEM, 0);
404         if (!res) {
405                 dev_err(&plat->dev, "no memory resource found\n");
406                 return -ENXIO;
407         }
408
409         ramips_fe_base = ioremap_nocache(res->start, res->end - res->start + 1);
410         if(!ramips_fe_base)
411                 return -ENOMEM;
412
413         ramips_dev = alloc_etherdev(sizeof(struct raeth_priv));
414         if(!ramips_dev) {
415                 dev_err(&plat->dev, "alloc_etherdev failed\n");
416                 err = -ENOMEM;
417                 goto err_unmap;
418         }
419
420         strcpy(ramips_dev->name, "eth%d");
421         ramips_dev->irq = platform_get_irq(plat, 0);
422         if (ramips_dev->irq < 0) {
423                 dev_err(&plat->dev, "no IRQ resource found\n");
424                 err = -ENXIO;
425                 goto err_free_dev;
426         }
427         ramips_dev->addr_len = ETH_ALEN;
428         ramips_dev->base_addr = (unsigned long)ramips_fe_base;
429         ramips_dev->init = ramips_eth_probe;
430         priv = (struct raeth_priv*)netdev_priv(ramips_dev);
431         priv->plat = data;
432
433         err = register_netdev(ramips_dev);
434         if (err) {
435                 dev_err(&plat->dev, "error bringing up device\n");
436                 goto err_free_dev;
437         }
438
439 #ifdef CONFIG_RALINK_RT305X
440         rt305x_esw_init();
441 #endif
442         printk(KERN_DEBUG "ramips_eth: loaded\n");
443         return 0;
444
445  err_free_dev:
446         kfree(ramips_dev);
447  err_unmap:
448         iounmap(ramips_fe_base);
449         return err;
450 }
451
452 static int
453 ramips_eth_plat_remove(struct platform_device *plat)
454 {
455         unregister_netdev(ramips_dev);
456         free_netdev(ramips_dev);
457         printk(KERN_DEBUG "ramips_eth: unloaded\n");
458         return 0;
459 }
460
461 static struct platform_driver ramips_eth_driver = {
462         .probe = ramips_eth_plat_probe,
463         .remove = ramips_eth_plat_remove,
464         .driver = {
465                 .name = "ramips_eth",
466                 .owner = THIS_MODULE,
467         },
468 };
469
470 static int __init
471 ramips_eth_init(void)
472 {
473         int ret = platform_driver_register(&ramips_eth_driver);
474         if (ret)
475                 printk(KERN_ERR
476                        "ramips_eth: Error registering platfom driver!\n");
477         return ret;
478 }
479
480 static void __exit
481 ramips_eth_cleanup(void)
482 {
483         platform_driver_unregister(&ramips_eth_driver);
484 }
485
486 module_init(ramips_eth_init);
487 module_exit(ramips_eth_cleanup);
488
489 MODULE_LICENSE("GPL");
490 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
491 MODULE_DESCRIPTION("ethernet driver for ramips boards");