Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * IXP2000 MSF network device driver
3 * Copyright (C) 2004, 2005 Lennert Buytenhek <buytenh@wantstofly.org>
4 * Dedicated to Marija Kulikova.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/netdevice.h>
15#include <linux/etherdevice.h>
16#include <linux/init.h>
17#include <linux/moduleparam.h>
18#include <asm/hardware/uengine.h>
19#include <asm/mach-types.h>
20#include <asm/io.h>
21#include "ixp2400_rx.ucode"
22#include "ixp2400_tx.ucode"
23#include "ixpdev_priv.h"
24#include "ixpdev.h"
25
26#define DRV_MODULE_VERSION "0.2"
27
28static int nds_count;
29static struct net_device **nds;
30static int nds_open;
31static void (*set_port_admin_status)(int port, int up);
32
33static struct ixpdev_rx_desc * const rx_desc =
34 (struct ixpdev_rx_desc *)(IXP2000_SRAM0_VIRT_BASE + RX_BUF_DESC_BASE);
35static struct ixpdev_tx_desc * const tx_desc =
36 (struct ixpdev_tx_desc *)(IXP2000_SRAM0_VIRT_BASE + TX_BUF_DESC_BASE);
37static int tx_pointer;
38
39
40static int ixpdev_xmit(struct sk_buff *skb, struct net_device *dev)
41{
42 struct ixpdev_priv *ip = netdev_priv(dev);
43 struct ixpdev_tx_desc *desc;
44 int entry;
45
46 if (unlikely(skb->len > PAGE_SIZE)) {
47 /* @@@ Count drops. */
48 dev_kfree_skb(skb);
49 return 0;
50 }
51
52 entry = tx_pointer;
53 tx_pointer = (tx_pointer + 1) % TX_BUF_COUNT;
54
55 desc = tx_desc + entry;
56 desc->pkt_length = skb->len;
57 desc->channel = ip->channel;
58
59 skb_copy_and_csum_dev(skb, phys_to_virt(desc->buf_addr));
60 dev_kfree_skb(skb);
61
62 ixp2000_reg_write(RING_TX_PENDING,
63 TX_BUF_DESC_BASE + (entry * sizeof(struct ixpdev_tx_desc)));
64
65 dev->trans_start = jiffies;
66
67 local_irq_disable();
68 ip->tx_queue_entries++;
69 if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
70 netif_stop_queue(dev);
71 local_irq_enable();
72
73 return 0;
74}
75
76
77static int ixpdev_rx(struct net_device *dev, int *budget)
78{
79 while (*budget > 0) {
80 struct ixpdev_rx_desc *desc;
81 struct sk_buff *skb;
82 void *buf;
83 u32 _desc;
84
85 _desc = ixp2000_reg_read(RING_RX_DONE);
86 if (_desc == 0)
87 return 0;
88
89 desc = rx_desc +
90 ((_desc - RX_BUF_DESC_BASE) / sizeof(struct ixpdev_rx_desc));
91 buf = phys_to_virt(desc->buf_addr);
92
93 if (desc->pkt_length < 4 || desc->pkt_length > PAGE_SIZE) {
94 printk(KERN_ERR "ixp2000: rx err, length %d\n",
95 desc->pkt_length);
96 goto err;
97 }
98
99 if (desc->channel < 0 || desc->channel >= nds_count) {
100 printk(KERN_ERR "ixp2000: rx err, channel %d\n",
101 desc->channel);
102 goto err;
103 }
104
105 /* @@@ Make FCS stripping configurable. */
106 desc->pkt_length -= 4;
107
108 if (unlikely(!netif_running(nds[desc->channel])))
109 goto err;
110
111 skb = dev_alloc_skb(desc->pkt_length + 2);
112 if (likely(skb != NULL)) {
113 skb->dev = nds[desc->channel];
114 skb_reserve(skb, 2);
115 eth_copy_and_sum(skb, buf, desc->pkt_length, 0);
116 skb_put(skb, desc->pkt_length);
117 skb->protocol = eth_type_trans(skb, skb->dev);
118
119 skb->dev->last_rx = jiffies;
120
121 netif_receive_skb(skb);
122 }
123
124err:
125 ixp2000_reg_write(RING_RX_PENDING, _desc);
126 dev->quota--;
127 (*budget)--;
128 }
129
130 return 1;
131}
132
133/* dev always points to nds[0]. */
134static int ixpdev_poll(struct net_device *dev, int *budget)
135{
136 /* @@@ Have to stop polling when nds[0] is administratively
137 * downed while we are polling. */
138 do {
139 ixp2000_reg_write(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0x00ff);
140
141 if (ixpdev_rx(dev, budget))
142 return 1;
143 } while (ixp2000_reg_read(IXP2000_IRQ_THD_RAW_STATUS_A_0) & 0x00ff);
144
145 netif_rx_complete(dev);
146 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0x00ff);
147
148 return 0;
149}
150
151static void ixpdev_tx_complete(void)
152{
153 int channel;
154 u32 wake;
155
156 wake = 0;
157 while (1) {
158 struct ixpdev_priv *ip;
159 u32 desc;
160 int entry;
161
162 desc = ixp2000_reg_read(RING_TX_DONE);
163 if (desc == 0)
164 break;
165
166 /* @@@ Check whether entries come back in order. */
167 entry = (desc - TX_BUF_DESC_BASE) / sizeof(struct ixpdev_tx_desc);
168 channel = tx_desc[entry].channel;
169
170 if (channel < 0 || channel >= nds_count) {
171 printk(KERN_ERR "ixp2000: txcomp channel index "
172 "out of bounds (%d, %.8i, %d)\n",
173 channel, (unsigned int)desc, entry);
174 continue;
175 }
176
177 ip = netdev_priv(nds[channel]);
178 if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
179 wake |= 1 << channel;
180 ip->tx_queue_entries--;
181 }
182
183 for (channel = 0; wake != 0; channel++) {
184 if (wake & (1 << channel)) {
185 netif_wake_queue(nds[channel]);
186 wake &= ~(1 << channel);
187 }
188 }
189}
190
191static irqreturn_t ixpdev_interrupt(int irq, void *dev_id, struct pt_regs *regs)
192{
193 u32 status;
194
195 status = ixp2000_reg_read(IXP2000_IRQ_THD_STATUS_A_0);
196 if (status == 0)
197 return IRQ_NONE;
198
199 /*
200 * Any of the eight receive units signaled RX?
201 */
202 if (status & 0x00ff) {
203 ixp2000_reg_wrb(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0x00ff);
204 if (likely(__netif_rx_schedule_prep(nds[0]))) {
205 __netif_rx_schedule(nds[0]);
206 } else {
207 printk(KERN_CRIT "ixp2000: irq while polling!!\n");
208 }
209 }
210
211 /*
212 * Any of the eight transmit units signaled TXdone?
213 */
214 if (status & 0xff00) {
215 ixp2000_reg_wrb(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0xff00);
216 ixpdev_tx_complete();
217 }
218
219 return IRQ_HANDLED;
220}
221
222#ifdef CONFIG_NET_POLL_CONTROLLER
223static void ixpdev_poll_controller(struct net_device *dev)
224{
225 disable_irq(IRQ_IXP2000_THDA0);
226 ixpdev_interrupt(IRQ_IXP2000_THDA0, dev, NULL);
227 enable_irq(IRQ_IXP2000_THDA0);
228}
229#endif
230
231static int ixpdev_open(struct net_device *dev)
232{
233 struct ixpdev_priv *ip = netdev_priv(dev);
234 int err;
235
236 if (!nds_open++) {
237 err = request_irq(IRQ_IXP2000_THDA0, ixpdev_interrupt,
238 IRQF_SHARED, "ixp2000_eth", nds);
239 if (err) {
240 nds_open--;
241 return err;
242 }
243
244 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0xffff);
245 }
246
247 set_port_admin_status(ip->channel, 1);
248 netif_start_queue(dev);
249
250 return 0;
251}
252
253static int ixpdev_close(struct net_device *dev)
254{
255 struct ixpdev_priv *ip = netdev_priv(dev);
256
257 netif_stop_queue(dev);
258 set_port_admin_status(ip->channel, 0);
259
260 if (!--nds_open) {
261 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0xffff);
262 free_irq(IRQ_IXP2000_THDA0, nds);
263 }
264
265 return 0;
266}
267
268struct net_device *ixpdev_alloc(int channel, int sizeof_priv)
269{
270 struct net_device *dev;
271 struct ixpdev_priv *ip;
272
273 dev = alloc_etherdev(sizeof_priv);
274 if (dev == NULL)
275 return NULL;
276
277 dev->hard_start_xmit = ixpdev_xmit;
278 dev->poll = ixpdev_poll;
279 dev->open = ixpdev_open;
280 dev->stop = ixpdev_close;
281#ifdef CONFIG_NET_POLL_CONTROLLER
282 dev->poll_controller = ixpdev_poll_controller;
283#endif
284
285 dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
286 dev->weight = 64;
287
288 ip = netdev_priv(dev);
289 ip->channel = channel;
290 ip->tx_queue_entries = 0;
291
292 return dev;
293}
294
295int ixpdev_init(int __nds_count, struct net_device **__nds,
296 void (*__set_port_admin_status)(int port, int up))
297{
298 int i;
299 int err;
300
301 BUILD_BUG_ON(RX_BUF_COUNT > 192 || TX_BUF_COUNT > 192);
302
303 printk(KERN_INFO "IXP2000 MSF ethernet driver %s\n", DRV_MODULE_VERSION);
304
305 nds_count = __nds_count;
306 nds = __nds;
307 set_port_admin_status = __set_port_admin_status;
308
309 for (i = 0; i < RX_BUF_COUNT; i++) {
310 void *buf;
311
312 buf = (void *)get_zeroed_page(GFP_KERNEL);
313 if (buf == NULL) {
314 err = -ENOMEM;
315 while (--i >= 0)
316 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
317 goto err_out;
318 }
319 rx_desc[i].buf_addr = virt_to_phys(buf);
320 rx_desc[i].buf_length = PAGE_SIZE;
321 }
322
323 /* @@@ Maybe we shouldn't be preallocating TX buffers. */
324 for (i = 0; i < TX_BUF_COUNT; i++) {
325 void *buf;
326
327 buf = (void *)get_zeroed_page(GFP_KERNEL);
328 if (buf == NULL) {
329 err = -ENOMEM;
330 while (--i >= 0)
331 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
332 goto err_free_rx;
333 }
334 tx_desc[i].buf_addr = virt_to_phys(buf);
335 }
336
337 /* 256 entries, ring status set means 'empty', base address 0x0000. */
338 ixp2000_reg_write(RING_RX_PENDING_BASE, 0x44000000);
339 ixp2000_reg_write(RING_RX_PENDING_HEAD, 0x00000000);
340 ixp2000_reg_write(RING_RX_PENDING_TAIL, 0x00000000);
341
342 /* 256 entries, ring status set means 'full', base address 0x0400. */
343 ixp2000_reg_write(RING_RX_DONE_BASE, 0x40000400);
344 ixp2000_reg_write(RING_RX_DONE_HEAD, 0x00000000);
345 ixp2000_reg_write(RING_RX_DONE_TAIL, 0x00000000);
346
347 for (i = 0; i < RX_BUF_COUNT; i++) {
348 ixp2000_reg_write(RING_RX_PENDING,
349 RX_BUF_DESC_BASE + (i * sizeof(struct ixpdev_rx_desc)));
350 }
351
352 ixp2000_uengine_load(0, &ixp2400_rx);
353 ixp2000_uengine_start_contexts(0, 0xff);
354
355 /* 256 entries, ring status set means 'empty', base address 0x0800. */
356 ixp2000_reg_write(RING_TX_PENDING_BASE, 0x44000800);
357 ixp2000_reg_write(RING_TX_PENDING_HEAD, 0x00000000);
358 ixp2000_reg_write(RING_TX_PENDING_TAIL, 0x00000000);
359
360 /* 256 entries, ring status set means 'full', base address 0x0c00. */
361 ixp2000_reg_write(RING_TX_DONE_BASE, 0x40000c00);
362 ixp2000_reg_write(RING_TX_DONE_HEAD, 0x00000000);
363 ixp2000_reg_write(RING_TX_DONE_TAIL, 0x00000000);
364
365 ixp2000_uengine_load(1, &ixp2400_tx);
366 ixp2000_uengine_start_contexts(1, 0xff);
367
368 for (i = 0; i < nds_count; i++) {
369 err = register_netdev(nds[i]);
370 if (err) {
371 while (--i >= 0)
372 unregister_netdev(nds[i]);
373 goto err_free_tx;
374 }
375 }
376
377 for (i = 0; i < nds_count; i++) {
378 printk(KERN_INFO "%s: IXP2000 MSF ethernet (port %d), "
379 "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x.\n", nds[i]->name, i,
380 nds[i]->dev_addr[0], nds[i]->dev_addr[1],
381 nds[i]->dev_addr[2], nds[i]->dev_addr[3],
382 nds[i]->dev_addr[4], nds[i]->dev_addr[5]);
383 }
384
385 return 0;
386
387err_free_tx:
388 for (i = 0; i < TX_BUF_COUNT; i++)
389 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
390
391err_free_rx:
392 for (i = 0; i < RX_BUF_COUNT; i++)
393 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
394
395err_out:
396 return err;
397}
398
399void ixpdev_deinit(void)
400{
401 int i;
402
403 /* @@@ Flush out pending packets. */
404
405 for (i = 0; i < nds_count; i++)
406 unregister_netdev(nds[i]);
407
408 ixp2000_uengine_stop_contexts(1, 0xff);
409 ixp2000_uengine_stop_contexts(0, 0xff);
410 ixp2000_uengine_reset(0x3);
411
412 for (i = 0; i < TX_BUF_COUNT; i++)
413 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
414
415 for (i = 0; i < RX_BUF_COUNT; i++)
416 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
417}