summaryrefslogtreecommitdiffstats
path: root/drivers/net/ixp2000/ixpdev.c
blob: e9d978a1d6b4f1a9db17064fd29dcf9573a225a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
/*
 * IXP2000 MSF network device driver
 * Copyright (C) 2004, 2005 Lennert Buytenhek <buytenh@wantstofly.org>
 * Dedicated to Marija Kulikova.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <asm/arch/uengine.h>
#include <asm/mach-types.h>
#include <asm/io.h>
#include "ixp2400_rx.ucode"
#include "ixp2400_tx.ucode"
#include "ixpdev_priv.h"
#include "ixpdev.h"

static int nds_count;
static struct net_device **nds;
static int nds_open;
static void (*set_port_admin_status)(int port, int up);

static struct ixpdev_rx_desc * const rx_desc =
	(struct ixpdev_rx_desc *)(IXP2000_SRAM0_VIRT_BASE + RX_BUF_DESC_BASE);
static struct ixpdev_tx_desc * const tx_desc =
	(struct ixpdev_tx_desc *)(IXP2000_SRAM0_VIRT_BASE + TX_BUF_DESC_BASE);
static int tx_pointer;


static int ixpdev_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct ixpdev_priv *ip = netdev_priv(dev);
	struct ixpdev_tx_desc *desc;
	int entry;

	if (unlikely(skb->len > PAGE_SIZE)) {
		/* @@@ Count drops.  */
		dev_kfree_skb(skb);
		return 0;
	}

	entry = tx_pointer;
	tx_pointer = (tx_pointer + 1) % TX_BUF_COUNT;

	desc = tx_desc + entry;
	desc->pkt_length = skb->len;
	desc->channel = ip->channel;

	skb_copy_and_csum_dev(skb, phys_to_virt(desc->buf_addr));
	dev_kfree_skb(skb);

	ixp2000_reg_write(RING_TX_PENDING,
		TX_BUF_DESC_BASE + (entry * sizeof(struct ixpdev_tx_desc)));

	dev->trans_start = jiffies;

	local_irq_disable();
	ip->tx_queue_entries++;
	if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
		netif_stop_queue(dev);
	local_irq_enable();

	return 0;
}


static int ixpdev_rx(struct net_device *dev, int *budget)
{
	while (*budget > 0) {
		struct ixpdev_rx_desc *desc;
		struct sk_buff *skb;
		void *buf;
		u32 _desc;

		_desc = ixp2000_reg_read(RING_RX_DONE);
		if (_desc == 0)
			return 0;

		desc = rx_desc +
			((_desc - RX_BUF_DESC_BASE) / sizeof(struct ixpdev_rx_desc));
		buf = phys_to_virt(desc->buf_addr);

		if (desc->pkt_length < 4 || desc->pkt_length > PAGE_SIZE) {
			printk(KERN_ERR "ixp2000: rx err, length %d\n",
					desc->pkt_length);
			goto err;
		}

		if (desc->channel < 0 || desc->channel >= nds_count) {
			printk(KERN_ERR "ixp2000: rx err, channel %d\n",
					desc->channel);
			goto err;
		}

		/* @@@ Make FCS stripping configurable.  */
		desc->pkt_length -= 4;

		if (unlikely(!netif_running(nds[desc->channel])))
			goto err;

		skb = dev_alloc_skb(desc->pkt_length + 2);
		if (likely(skb != NULL)) {
			skb->dev = nds[desc->channel];
			skb_reserve(skb, 2);
			eth_copy_and_sum(skb, buf, desc->pkt_length, 0);
			skb_put(skb, desc->pkt_length);
			skb->protocol = eth_type_trans(skb, skb->dev);

			skb->dev->last_rx = jiffies;

			netif_receive_skb(skb);
		}

err:
		ixp2000_reg_write(RING_RX_PENDING, _desc);
		dev->quota--;
		(*budget)--;
	}

	return 1;
}

/* dev always points to nds[0].  */
static int ixpdev_poll(struct net_device *dev, int *budget)
{
	/* @@@ Have to stop polling when nds[0] is administratively
	 * downed while we are polling.  */
	do {
		ixp2000_reg_write(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0x00ff);

		if (ixpdev_rx(dev, budget))
			return 1;
	} while (ixp2000_reg_read(IXP2000_IRQ_THD_RAW_STATUS_A_0) & 0x00ff);

	netif_rx_complete(dev);
	ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0x00ff);

	return 0;
}

static void ixpdev_tx_complete(void)
{
	int channel;
	u32 wake;

	wake = 0;
	while (1) {
		struct ixpdev_priv *ip;
		u32 desc;
		int entry;

		desc = ixp2000_reg_read(RING_TX_DONE);
		if (desc == 0)
			break;

		/* @@@ Check whether entries come back in order.  */
		entry = (desc - TX_BUF_DESC_BASE) / sizeof(struct ixpdev_tx_desc);
		channel = tx_desc[entry].channel;

		if (channel < 0 || channel >= nds_count) {
			printk(KERN_ERR "ixp2000: txcomp channel index "
					"out of bounds (%d, %.8i, %d)\n",
					channel, (unsigned int)desc, entry);
			continue;
		}

		ip = netdev_priv(nds[channel]);
		if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
			wake |= 1 << channel;
		ip->tx_queue_entries--;
	}

	for (channel = 0; wake != 0; channel++) {
		if (wake & (1 << channel)) {
			netif_wake_queue(nds[channel]);
			wake &= ~(1 << channel);
		}
	}
}

static irqreturn_t ixpdev_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	u32 status;

	status = ixp2000_reg_read(IXP2000_IRQ_THD_STATUS_A_0);
	if (status == 0)
		return IRQ_NONE;

	/*
	 * Any of the eight receive units signaled RX?
	 */
	if (status & 0x00ff) {
		ixp2000_reg_wrb(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0x00ff);
		if (likely(netif_rx_schedule_test(nds[0]))) {
			__netif_rx_schedule(nds[0]);
		} else {
			printk(KERN_CRIT "ixp2000: irq while polling!!\n");
		}
	}

	/*
	 * Any of the eight transmit units signaled TXdone?
	 */
	if (status & 0xff00) {
		ixp2000_reg_wrb(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0xff00);
		ixpdev_tx_complete();
	}

	return IRQ_HANDLED;
}

static int ixpdev_open(struct net_device *dev)
{
	struct ixpdev_priv *ip = netdev_priv(dev);
	int err;

	if (!nds_open++) {
		err = request_irq(IRQ_IXP2000_THDA0, ixpdev_interrupt,
					SA_SHIRQ, "ixp2000_eth", nds);
		if (err) {
			nds_open--;
			return err;
		}

		ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0xffff);
	}

	set_port_admin_status(ip->channel, 1);
	netif_start_queue(dev);

	return 0;
}

static int ixpdev_close(struct net_device *dev)
{
	struct ixpdev_priv *ip = netdev_priv(dev);

	netif_stop_queue(dev);
	set_port_admin_status(ip->channel, 0);

	if (!--nds_open) {
		ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0xffff);
		free_irq(IRQ_IXP2000_THDA0, nds);
	}

	return 0;
}

struct net_device *ixpdev_alloc(int channel, int sizeof_priv)
{
	struct net_device *dev;
	struct ixpdev_priv *ip;

	dev = alloc_etherdev(sizeof_priv);
	if (dev == NULL)
		return NULL;

	dev->hard_start_xmit = ixpdev_xmit;
	dev->poll = ixpdev_poll;
	dev->open = ixpdev_open;
	dev->stop = ixpdev_close;

	dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
	dev->weight = 64;

	ip = netdev_priv(dev);
	ip->channel = channel;
	ip->tx_queue_entries = 0;

	return dev;
}

int ixpdev_init(int __nds_count, struct net_device **__nds,
		void (*__set_port_admin_status)(int port, int up))
{
	int i;
	int err;

	if (RX_BUF_COUNT > 192 || TX_BUF_COUNT > 192) {
		static void __too_many_rx_or_tx_buffers(void);
		__too_many_rx_or_tx_buffers();
	}

	nds_count = __nds_count;
	nds = __nds;
	set_port_admin_status = __set_port_admin_status;

	for (i = 0; i < RX_BUF_COUNT; i++) {
		void *buf;

		buf = (void *)get_zeroed_page(GFP_KERNEL);
		if (buf == NULL) {
			err = -ENOMEM;
			while (--i >= 0)
				free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
			goto err_out;
		}
		rx_desc[i].buf_addr = virt_to_phys(buf);
		rx_desc[i].buf_length = PAGE_SIZE;
	}

	/* @@@ Maybe we shouldn't be preallocating TX buffers.  */
	for (i = 0; i < TX_BUF_COUNT; i++) {
		void *buf;

		buf = (void *)get_zeroed_page(GFP_KERNEL);
		if (buf == NULL) {
			err = -ENOMEM;
			while (--i >= 0)
				free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
			goto err_free_rx;
		}
		tx_desc[i].buf_addr = virt_to_phys(buf);
	}

	/* 256 entries, ring status set means 'empty', base address 0x0000.  */
	ixp2000_reg_write(RING_RX_PENDING_BASE, 0x44000000);
	ixp2000_reg_write(RING_RX_PENDING_HEAD, 0x00000000);
	ixp2000_reg_write(RING_RX_PENDING_TAIL, 0x00000000);

	/* 256 entries, ring status set means 'full', base address 0x0400.  */
	ixp2000_reg_write(RING_RX_DONE_BASE, 0x40000400);
	ixp2000_reg_write(RING_RX_DONE_HEAD, 0x00000000);
	ixp2000_reg_write(RING_RX_DONE_TAIL, 0x00000000);

	for (i = 0; i < RX_BUF_COUNT; i++) {
		ixp2000_reg_write(RING_RX_PENDING,
			RX_BUF_DESC_BASE + (i * sizeof(struct ixpdev_rx_desc)));
	}

	ixp2000_uengine_load(0, &ixp2400_rx);
	ixp2000_uengine_start_contexts(0, 0xff);

	/* 256 entries, ring status set means 'empty', base address 0x0800.  */
	ixp2000_reg_write(RING_TX_PENDING_BASE, 0x44000800);
	ixp2000_reg_write(RING_TX_PENDING_HEAD, 0x00000000);
	ixp2000_reg_write(RING_TX_PENDING_TAIL, 0x00000000);

	/* 256 entries, ring status set means 'full', base address 0x0c00.  */
	ixp2000_reg_write(RING_TX_DONE_BASE, 0x40000c00);
	ixp2000_reg_write(RING_TX_DONE_HEAD, 0x00000000);
	ixp2000_reg_write(RING_TX_DONE_TAIL, 0x00000000);

	ixp2000_uengine_load(1, &ixp2400_tx);
	ixp2000_uengine_start_contexts(1, 0xff);

	for (i = 0; i < nds_count; i++) {
		err = register_netdev(nds[i]);
		if (err) {
			while (--i >= 0)
				unregister_netdev(nds[i]);
			goto err_free_tx;
		}
	}

	return 0;

err_free_tx:
	for (i = 0; i < TX_BUF_COUNT; i++)
		free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));

err_free_rx:
	for (i = 0; i < RX_BUF_COUNT; i++)
		free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));

err_out:
	return err;
} 

void ixpdev_deinit(void)
{
	int i;

	/* @@@ Flush out pending packets.  */

	for (i = 0; i < nds_count; i++)
		unregister_netdev(nds[i]);

	ixp2000_uengine_stop_contexts(1, 0xff);
	ixp2000_uengine_stop_contexts(0, 0xff);
	ixp2000_uengine_reset(0x3);

	for (i = 0; i < TX_BUF_COUNT; i++)
		free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));

	for (i = 0; i < RX_BUF_COUNT; i++)
		free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
}
OpenPOWER on IntegriCloud