ia64/linux-2.6.18-xen.hg

view drivers/net/znet.c @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
children
line source
1 /* znet.c: An Zenith Z-Note ethernet driver for linux. */
3 /*
4 Written by Donald Becker.
6 The author may be reached as becker@scyld.com.
7 This driver is based on the Linux skeleton driver. The copyright of the
8 skeleton driver is held by the United States Government, as represented
9 by DIRNSA, and it is released under the GPL.
11 Thanks to Mike Hollick for alpha testing and suggestions.
13 References:
14 The Crynwr packet driver.
16 "82593 CSMA/CD Core LAN Controller" Intel datasheet, 1992
17 Intel Microcommunications Databook, Vol. 1, 1990.
18 As usual with Intel, the documentation is incomplete and inaccurate.
19 I had to read the Crynwr packet driver to figure out how to actually
20 use the i82593, and guess at what register bits matched the loosely
21 related i82586.
23 Theory of Operation
25 The i82593 used in the Zenith Z-Note series operates using two(!) slave
26 DMA channels, one interrupt, and one 8-bit I/O port.
28 While there several ways to configure '593 DMA system, I chose the one
29 that seemed commensurate with the highest system performance in the face
30 of moderate interrupt latency: Both DMA channels are configured as
31 recirculating ring buffers, with one channel (#0) dedicated to Rx and
32 the other channel (#1) to Tx and configuration. (Note that this is
33 different than the Crynwr driver, where the Tx DMA channel is initialized
34 before each operation. That approach simplifies operation and Tx error
35 recovery, but requires additional I/O in normal operation and precludes
36 transmit buffer chaining.)
38 Both rings are set to 8192 bytes using {TX,RX}_RING_SIZE. This provides
39 a reasonable ring size for Rx, while simplifying DMA buffer allocation --
40 DMA buffers must not cross a 128K boundary. (In truth the size selection
41 was influenced by my lack of '593 documentation. I thus was constrained
42 to use the Crynwr '593 initialization table, which sets the Rx ring size
43 to 8K.)
45 Despite my usual low opinion about Intel-designed parts, I must admit
46 that the bulk data handling of the i82593 is a good design for
47 an integrated system, like a laptop, where using two slave DMA channels
48 doesn't pose a problem. I still take issue with using only a single I/O
49 port. In the same controlled environment there are essentially no
50 limitations on I/O space, and using multiple locations would eliminate
51 the need for multiple operations when looking at status registers,
52 setting the Rx ring boundary, or switching to promiscuous mode.
54 I also question Zenith's selection of the '593: one of the advertised
55 advantages of earlier Intel parts was that if you figured out the magic
56 initialization incantation you could use the same part on many different
57 network types. Zenith's use of the "FriendlyNet" (sic) connector rather
58 than an on-board transceiver leads me to believe that they were planning
59 to take advantage of this. But, uhmmm, the '593 omits all but ethernet
60 functionality from the serial subsystem.
61 */
63 /* 10/2002
65 o Resurected for Linux 2.5+ by Marc Zyngier <maz@wild-wind.fr.eu.org> :
67 - Removed strange DMA snooping in znet_sent_packet, which lead to
68 TX buffer corruption on my laptop.
69 - Use init_etherdev stuff.
70 - Use kmalloc-ed DMA buffers.
71 - Use as few global variables as possible.
72 - Use proper resources management.
73 - Use wireless/i82593.h as much as possible (structure, constants)
74 - Compiles as module or build-in.
75 - Now survives unplugging/replugging cable.
77 Some code was taken from wavelan_cs.
79 Tested on a vintage Zenith Z-Note 433Lnp+. Probably broken on
80 anything else. Testers (and detailed bug reports) are welcome :-).
82 o TODO :
84 - Properly handle multicast
85 - Understand why some traffic patterns add a 1s latency...
86 */
88 #include <linux/module.h>
89 #include <linux/kernel.h>
90 #include <linux/string.h>
91 #include <linux/errno.h>
92 #include <linux/interrupt.h>
93 #include <linux/ioport.h>
94 #include <linux/init.h>
95 #include <linux/delay.h>
96 #include <linux/netdevice.h>
97 #include <linux/etherdevice.h>
98 #include <linux/skbuff.h>
99 #include <linux/if_arp.h>
100 #include <linux/bitops.h>
102 #include <asm/system.h>
103 #include <asm/io.h>
104 #include <asm/dma.h>
106 /* This include could be elsewhere, since it is not wireless specific */
107 #include "wireless/i82593.h"
109 static char version[] __initdata = "znet.c:v1.02 9/23/94 becker@scyld.com\n";
111 #ifndef ZNET_DEBUG
112 #define ZNET_DEBUG 1
113 #endif
114 static unsigned int znet_debug = ZNET_DEBUG;
115 module_param (znet_debug, int, 0);
116 MODULE_PARM_DESC (znet_debug, "ZNet debug level");
117 MODULE_LICENSE("GPL");
119 /* The DMA modes we need aren't in <dma.h>. */
120 #define DMA_RX_MODE 0x14 /* Auto init, I/O to mem, ++, demand. */
121 #define DMA_TX_MODE 0x18 /* Auto init, Mem to I/O, ++, demand. */
122 #define dma_page_eq(ptr1, ptr2) ((long)(ptr1)>>17 == (long)(ptr2)>>17)
123 #define RX_BUF_SIZE 8192
124 #define TX_BUF_SIZE 8192
125 #define DMA_BUF_SIZE (RX_BUF_SIZE + 16) /* 8k + 16 bytes for trailers */
127 #define TX_TIMEOUT 10
129 struct znet_private {
130 int rx_dma, tx_dma;
131 struct net_device_stats stats;
132 spinlock_t lock;
133 short sia_base, sia_size, io_size;
134 struct i82593_conf_block i593_init;
135 /* The starting, current, and end pointers for the packet buffers. */
136 ushort *rx_start, *rx_cur, *rx_end;
137 ushort *tx_start, *tx_cur, *tx_end;
138 ushort tx_buf_len; /* Tx buffer length, in words. */
139 };
141 /* Only one can be built-in;-> */
142 static struct net_device *znet_dev;
144 struct netidblk {
145 char magic[8]; /* The magic number (string) "NETIDBLK" */
146 unsigned char netid[8]; /* The physical station address */
147 char nettype, globalopt;
148 char vendor[8]; /* The machine vendor and product name. */
149 char product[8];
150 char irq1, irq2; /* Interrupts, only one is currently used. */
151 char dma1, dma2;
152 short dma_mem_misc[8]; /* DMA buffer locations (unused in Linux). */
153 short iobase1, iosize1;
154 short iobase2, iosize2; /* Second iobase unused. */
155 char driver_options; /* Misc. bits */
156 char pad;
157 };
159 static int znet_open(struct net_device *dev);
160 static int znet_send_packet(struct sk_buff *skb, struct net_device *dev);
161 static irqreturn_t znet_interrupt(int irq, void *dev_id, struct pt_regs *regs);
162 static void znet_rx(struct net_device *dev);
163 static int znet_close(struct net_device *dev);
164 static struct net_device_stats *net_get_stats(struct net_device *dev);
165 static void hardware_init(struct net_device *dev);
166 static void update_stop_hit(short ioaddr, unsigned short rx_stop_offset);
167 static void znet_tx_timeout (struct net_device *dev);
169 /* Request needed resources */
170 static int znet_request_resources (struct net_device *dev)
171 {
172 struct znet_private *znet = dev->priv;
173 unsigned long flags;
175 if (request_irq (dev->irq, &znet_interrupt, 0, "ZNet", dev))
176 goto failed;
177 if (request_dma (znet->rx_dma, "ZNet rx"))
178 goto free_irq;
179 if (request_dma (znet->tx_dma, "ZNet tx"))
180 goto free_rx_dma;
181 if (!request_region (znet->sia_base, znet->sia_size, "ZNet SIA"))
182 goto free_tx_dma;
183 if (!request_region (dev->base_addr, znet->io_size, "ZNet I/O"))
184 goto free_sia;
186 return 0; /* Happy ! */
188 free_sia:
189 release_region (znet->sia_base, znet->sia_size);
190 free_tx_dma:
191 flags = claim_dma_lock();
192 free_dma (znet->tx_dma);
193 release_dma_lock (flags);
194 free_rx_dma:
195 flags = claim_dma_lock();
196 free_dma (znet->rx_dma);
197 release_dma_lock (flags);
198 free_irq:
199 free_irq (dev->irq, dev);
200 failed:
201 return -1;
202 }
204 static void znet_release_resources (struct net_device *dev)
205 {
206 struct znet_private *znet = dev->priv;
207 unsigned long flags;
209 release_region (znet->sia_base, znet->sia_size);
210 release_region (dev->base_addr, znet->io_size);
211 flags = claim_dma_lock();
212 free_dma (znet->tx_dma);
213 free_dma (znet->rx_dma);
214 release_dma_lock (flags);
215 free_irq (dev->irq, dev);
216 }
218 /* Keep the magical SIA stuff in a single function... */
219 static void znet_transceiver_power (struct net_device *dev, int on)
220 {
221 struct znet_private *znet = dev->priv;
222 unsigned char v;
224 /* Turn on/off the 82501 SIA, using zenith-specific magic. */
225 /* Select LAN control register */
226 outb(0x10, znet->sia_base);
228 if (on)
229 v = inb(znet->sia_base + 1) | 0x84;
230 else
231 v = inb(znet->sia_base + 1) & ~0x84;
233 outb(v, znet->sia_base+1); /* Turn on/off LAN power (bit 2). */
234 }
236 /* Init the i82593, with current promisc/mcast configuration.
237 Also used from hardware_init. */
238 static void znet_set_multicast_list (struct net_device *dev)
239 {
240 struct znet_private *znet = dev->priv;
241 short ioaddr = dev->base_addr;
242 struct i82593_conf_block *cfblk = &znet->i593_init;
244 memset(cfblk, 0x00, sizeof(struct i82593_conf_block));
246 /* The configuration block. What an undocumented nightmare.
247 The first set of values are those suggested (without explanation)
248 for ethernet in the Intel 82586 databook. The rest appear to be
249 completely undocumented, except for cryptic notes in the Crynwr
250 packet driver. This driver uses the Crynwr values verbatim. */
252 /* maz : Rewritten to take advantage of the wanvelan includes.
253 At least we have names, not just blind values */
255 /* Byte 0 */
256 cfblk->fifo_limit = 10; /* = 16 B rx and 80 B tx fifo thresholds */
257 cfblk->forgnesi = 0; /* 0=82C501, 1=AMD7992B compatibility */
258 cfblk->fifo_32 = 1;
259 cfblk->d6mod = 0; /* Run in i82593 advanced mode */
260 cfblk->throttle_enb = 1;
262 /* Byte 1 */
263 cfblk->throttle = 8; /* Continuous w/interrupts, 128-clock DMA. */
264 cfblk->cntrxint = 0; /* enable continuous mode receive interrupts */
265 cfblk->contin = 1; /* enable continuous mode */
267 /* Byte 2 */
268 cfblk->addr_len = ETH_ALEN;
269 cfblk->acloc = 1; /* Disable source addr insertion by i82593 */
270 cfblk->preamb_len = 2; /* 8 bytes preamble */
271 cfblk->loopback = 0; /* Loopback off */
273 /* Byte 3 */
274 cfblk->lin_prio = 0; /* Default priorities & backoff methods. */
275 cfblk->tbofstop = 0;
276 cfblk->exp_prio = 0;
277 cfblk->bof_met = 0;
279 /* Byte 4 */
280 cfblk->ifrm_spc = 6; /* 96 bit times interframe spacing */
282 /* Byte 5 */
283 cfblk->slottim_low = 0; /* 512 bit times slot time (low) */
285 /* Byte 6 */
286 cfblk->slottim_hi = 2; /* 512 bit times slot time (high) */
287 cfblk->max_retr = 15; /* 15 collisions retries */
289 /* Byte 7 */
290 cfblk->prmisc = ((dev->flags & IFF_PROMISC) ? 1 : 0); /* Promiscuous mode */
291 cfblk->bc_dis = 0; /* Enable broadcast reception */
292 cfblk->crs_1 = 0; /* Don't transmit without carrier sense */
293 cfblk->nocrc_ins = 0; /* i82593 generates CRC */
294 cfblk->crc_1632 = 0; /* 32-bit Autodin-II CRC */
295 cfblk->crs_cdt = 0; /* CD not to be interpreted as CS */
297 /* Byte 8 */
298 cfblk->cs_filter = 0; /* CS is recognized immediately */
299 cfblk->crs_src = 0; /* External carrier sense */
300 cfblk->cd_filter = 0; /* CD is recognized immediately */
302 /* Byte 9 */
303 cfblk->min_fr_len = ETH_ZLEN >> 2; /* Minimum frame length */
305 /* Byte A */
306 cfblk->lng_typ = 1; /* Type/length checks OFF */
307 cfblk->lng_fld = 1; /* Disable 802.3 length field check */
308 cfblk->rxcrc_xf = 1; /* Don't transfer CRC to memory */
309 cfblk->artx = 1; /* Disable automatic retransmission */
310 cfblk->sarec = 1; /* Disable source addr trig of CD */
311 cfblk->tx_jabber = 0; /* Disable jabber jam sequence */
312 cfblk->hash_1 = 1; /* Use bits 0-5 in mc address hash */
313 cfblk->lbpkpol = 0; /* Loopback pin active high */
315 /* Byte B */
316 cfblk->fdx = 0; /* Disable full duplex operation */
318 /* Byte C */
319 cfblk->dummy_6 = 0x3f; /* all ones, Default multicast addresses & backoff. */
320 cfblk->mult_ia = 0; /* No multiple individual addresses */
321 cfblk->dis_bof = 0; /* Disable the backoff algorithm ?! */
323 /* Byte D */
324 cfblk->dummy_1 = 1; /* set to 1 */
325 cfblk->tx_ifs_retrig = 3; /* Hmm... Disabled */
326 cfblk->mc_all = (dev->mc_list || (dev->flags&IFF_ALLMULTI));/* multicast all mode */
327 cfblk->rcv_mon = 0; /* Monitor mode disabled */
328 cfblk->frag_acpt = 0; /* Do not accept fragments */
329 cfblk->tstrttrs = 0; /* No start transmission threshold */
331 /* Byte E */
332 cfblk->fretx = 1; /* FIFO automatic retransmission */
333 cfblk->runt_eop = 0; /* drop "runt" packets */
334 cfblk->hw_sw_pin = 0; /* ?? */
335 cfblk->big_endn = 0; /* Big Endian ? no... */
336 cfblk->syncrqs = 1; /* Synchronous DRQ deassertion... */
337 cfblk->sttlen = 1; /* 6 byte status registers */
338 cfblk->rx_eop = 0; /* Signal EOP on packet reception */
339 cfblk->tx_eop = 0; /* Signal EOP on packet transmission */
341 /* Byte F */
342 cfblk->rbuf_size = RX_BUF_SIZE >> 12; /* Set receive buffer size */
343 cfblk->rcvstop = 1; /* Enable Receive Stop Register */
345 if (znet_debug > 2) {
346 int i;
347 unsigned char *c;
349 for (i = 0, c = (char *) cfblk; i < sizeof (*cfblk); i++)
350 printk ("%02X ", c[i]);
351 printk ("\n");
352 }
354 *znet->tx_cur++ = sizeof(struct i82593_conf_block);
355 memcpy(znet->tx_cur, cfblk, sizeof(struct i82593_conf_block));
356 znet->tx_cur += sizeof(struct i82593_conf_block)/2;
357 outb(OP0_CONFIGURE | CR0_CHNL, ioaddr);
359 /* XXX FIXME maz : Add multicast addresses here, so having a
360 * multicast address configured isn't equal to IFF_ALLMULTI */
361 }
363 /* The Z-Note probe is pretty easy. The NETIDBLK exists in the safe-to-probe
364 BIOS area. We just scan for the signature, and pull the vital parameters
365 out of the structure. */
367 static int __init znet_probe (void)
368 {
369 int i;
370 struct netidblk *netinfo;
371 struct znet_private *znet;
372 struct net_device *dev;
373 char *p;
374 int err = -ENOMEM;
376 /* This code scans the region 0xf0000 to 0xfffff for a "NETIDBLK". */
377 for(p = (char *)phys_to_virt(0xf0000); p < (char *)phys_to_virt(0x100000); p++)
378 if (*p == 'N' && strncmp(p, "NETIDBLK", 8) == 0)
379 break;
381 if (p >= (char *)phys_to_virt(0x100000)) {
382 if (znet_debug > 1)
383 printk(KERN_INFO "No Z-Note ethernet adaptor found.\n");
384 return -ENODEV;
385 }
387 dev = alloc_etherdev(sizeof(struct znet_private));
388 if (!dev)
389 return -ENOMEM;
391 SET_MODULE_OWNER (dev);
393 znet = dev->priv;
395 netinfo = (struct netidblk *)p;
396 dev->base_addr = netinfo->iobase1;
397 dev->irq = netinfo->irq1;
399 printk(KERN_INFO "%s: ZNET at %#3lx,", dev->name, dev->base_addr);
401 /* The station address is in the "netidblk" at 0x0f0000. */
402 for (i = 0; i < 6; i++)
403 printk(" %2.2x", dev->dev_addr[i] = netinfo->netid[i]);
405 printk(", using IRQ %d DMA %d and %d.\n", dev->irq, netinfo->dma1,
406 netinfo->dma2);
408 if (znet_debug > 1) {
409 printk(KERN_INFO "%s: vendor '%16.16s' IRQ1 %d IRQ2 %d DMA1 %d DMA2 %d.\n",
410 dev->name, netinfo->vendor,
411 netinfo->irq1, netinfo->irq2,
412 netinfo->dma1, netinfo->dma2);
413 printk(KERN_INFO "%s: iobase1 %#x size %d iobase2 %#x size %d net type %2.2x.\n",
414 dev->name, netinfo->iobase1, netinfo->iosize1,
415 netinfo->iobase2, netinfo->iosize2, netinfo->nettype);
416 }
418 if (znet_debug > 0)
419 printk(KERN_INFO "%s", version);
421 znet->rx_dma = netinfo->dma1;
422 znet->tx_dma = netinfo->dma2;
423 spin_lock_init(&znet->lock);
424 znet->sia_base = 0xe6; /* Magic address for the 82501 SIA */
425 znet->sia_size = 2;
426 /* maz: Despite the '593 being advertised above as using a
427 * single 8bits I/O port, this driver does many 16bits
428 * access. So set io_size accordingly */
429 znet->io_size = 2;
431 if (!(znet->rx_start = kmalloc (DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA)))
432 goto free_dev;
433 if (!(znet->tx_start = kmalloc (DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA)))
434 goto free_rx;
436 if (!dma_page_eq (znet->rx_start, znet->rx_start + (RX_BUF_SIZE/2-1)) ||
437 !dma_page_eq (znet->tx_start, znet->tx_start + (TX_BUF_SIZE/2-1))) {
438 printk (KERN_WARNING "tx/rx crossing DMA frontiers, giving up\n");
439 goto free_tx;
440 }
442 znet->rx_end = znet->rx_start + RX_BUF_SIZE/2;
443 znet->tx_buf_len = TX_BUF_SIZE/2;
444 znet->tx_end = znet->tx_start + znet->tx_buf_len;
446 /* The ZNET-specific entries in the device structure. */
447 dev->open = &znet_open;
448 dev->hard_start_xmit = &znet_send_packet;
449 dev->stop = &znet_close;
450 dev->get_stats = net_get_stats;
451 dev->set_multicast_list = &znet_set_multicast_list;
452 dev->tx_timeout = znet_tx_timeout;
453 dev->watchdog_timeo = TX_TIMEOUT;
454 err = register_netdev(dev);
455 if (err)
456 goto free_tx;
457 znet_dev = dev;
458 return 0;
460 free_tx:
461 kfree(znet->tx_start);
462 free_rx:
463 kfree(znet->rx_start);
464 free_dev:
465 free_netdev(dev);
466 return err;
467 }
470 static int znet_open(struct net_device *dev)
471 {
472 int ioaddr = dev->base_addr;
474 if (znet_debug > 2)
475 printk(KERN_DEBUG "%s: znet_open() called.\n", dev->name);
477 /* These should never fail. You can't add devices to a sealed box! */
478 if (znet_request_resources (dev)) {
479 printk(KERN_WARNING "%s: Not opened -- resource busy?!?\n", dev->name);
480 return -EBUSY;
481 }
483 znet_transceiver_power (dev, 1);
485 /* According to the Crynwr driver we should wait 50 msec. for the
486 LAN clock to stabilize. My experiments indicates that the '593 can
487 be initialized immediately. The delay is probably needed for the
488 DC-to-DC converter to come up to full voltage, and for the oscillator
489 to be spot-on at 20Mhz before transmitting.
490 Until this proves to be a problem we rely on the higher layers for the
491 delay and save allocating a timer entry. */
493 /* maz : Well, I'm getting every time the following message
494 * without the delay on a 486@33. This machine is much too
495 * fast... :-) So maybe the Crynwr driver wasn't wrong after
496 * all, even if the message is completly harmless on my
497 * setup. */
498 mdelay (50);
500 /* This follows the packet driver's lead, and checks for success. */
501 if (inb(ioaddr) != 0x10 && inb(ioaddr) != 0x00)
502 printk(KERN_WARNING "%s: Problem turning on the transceiver power.\n",
503 dev->name);
505 hardware_init(dev);
506 netif_start_queue (dev);
508 return 0;
509 }
512 static void znet_tx_timeout (struct net_device *dev)
513 {
514 int ioaddr = dev->base_addr;
515 ushort event, tx_status, rx_offset, state;
517 outb (CR0_STATUS_0, ioaddr);
518 event = inb (ioaddr);
519 outb (CR0_STATUS_1, ioaddr);
520 tx_status = inw (ioaddr);
521 outb (CR0_STATUS_2, ioaddr);
522 rx_offset = inw (ioaddr);
523 outb (CR0_STATUS_3, ioaddr);
524 state = inb (ioaddr);
525 printk (KERN_WARNING "%s: transmit timed out, status %02x %04x %04x %02x,"
526 " resetting.\n", dev->name, event, tx_status, rx_offset, state);
527 if (tx_status == TX_LOST_CRS)
528 printk (KERN_WARNING "%s: Tx carrier error, check transceiver cable.\n",
529 dev->name);
530 outb (OP0_RESET, ioaddr);
531 hardware_init (dev);
532 netif_wake_queue (dev);
533 }
535 static int znet_send_packet(struct sk_buff *skb, struct net_device *dev)
536 {
537 int ioaddr = dev->base_addr;
538 struct znet_private *znet = dev->priv;
539 unsigned long flags;
540 short length = skb->len;
542 if (znet_debug > 4)
543 printk(KERN_DEBUG "%s: ZNet_send_packet.\n", dev->name);
545 if (length < ETH_ZLEN) {
546 if (skb_padto(skb, ETH_ZLEN))
547 return 0;
548 length = ETH_ZLEN;
549 }
551 netif_stop_queue (dev);
553 /* Check that the part hasn't reset itself, probably from suspend. */
554 outb(CR0_STATUS_0, ioaddr);
555 if (inw(ioaddr) == 0x0010 &&
556 inw(ioaddr) == 0x0000 &&
557 inw(ioaddr) == 0x0010) {
558 if (znet_debug > 1)
559 printk (KERN_WARNING "%s : waking up\n", dev->name);
560 hardware_init(dev);
561 znet_transceiver_power (dev, 1);
562 }
564 if (1) {
565 unsigned char *buf = (void *)skb->data;
566 ushort *tx_link = znet->tx_cur - 1;
567 ushort rnd_len = (length + 1)>>1;
569 znet->stats.tx_bytes+=length;
571 if (znet->tx_cur >= znet->tx_end)
572 znet->tx_cur = znet->tx_start;
573 *znet->tx_cur++ = length;
574 if (znet->tx_cur + rnd_len + 1 > znet->tx_end) {
575 int semi_cnt = (znet->tx_end - znet->tx_cur)<<1; /* Cvrt to byte cnt. */
576 memcpy(znet->tx_cur, buf, semi_cnt);
577 rnd_len -= semi_cnt>>1;
578 memcpy(znet->tx_start, buf + semi_cnt, length - semi_cnt);
579 znet->tx_cur = znet->tx_start + rnd_len;
580 } else {
581 memcpy(znet->tx_cur, buf, skb->len);
582 znet->tx_cur += rnd_len;
583 }
584 *znet->tx_cur++ = 0;
586 spin_lock_irqsave(&znet->lock, flags);
587 {
588 *tx_link = OP0_TRANSMIT | CR0_CHNL;
589 /* Is this always safe to do? */
590 outb(OP0_TRANSMIT | CR0_CHNL, ioaddr);
591 }
592 spin_unlock_irqrestore (&znet->lock, flags);
594 dev->trans_start = jiffies;
595 netif_start_queue (dev);
597 if (znet_debug > 4)
598 printk(KERN_DEBUG "%s: Transmitter queued, length %d.\n", dev->name, length);
599 }
600 dev_kfree_skb(skb);
601 return 0;
602 }
604 /* The ZNET interrupt handler. */
605 static irqreturn_t znet_interrupt(int irq, void *dev_id, struct pt_regs * regs)
606 {
607 struct net_device *dev = dev_id;
608 struct znet_private *znet = dev->priv;
609 int ioaddr;
610 int boguscnt = 20;
611 int handled = 0;
613 if (dev == NULL) {
614 printk(KERN_WARNING "znet_interrupt(): IRQ %d for unknown device.\n", irq);
615 return IRQ_NONE;
616 }
618 spin_lock (&znet->lock);
620 ioaddr = dev->base_addr;
622 outb(CR0_STATUS_0, ioaddr);
623 do {
624 ushort status = inb(ioaddr);
625 if (znet_debug > 5) {
626 ushort result, rx_ptr, running;
627 outb(CR0_STATUS_1, ioaddr);
628 result = inw(ioaddr);
629 outb(CR0_STATUS_2, ioaddr);
630 rx_ptr = inw(ioaddr);
631 outb(CR0_STATUS_3, ioaddr);
632 running = inb(ioaddr);
633 printk(KERN_DEBUG "%s: interrupt, status %02x, %04x %04x %02x serial %d.\n",
634 dev->name, status, result, rx_ptr, running, boguscnt);
635 }
636 if ((status & SR0_INTERRUPT) == 0)
637 break;
639 handled = 1;
641 if ((status & SR0_EVENT_MASK) == SR0_TRANSMIT_DONE ||
642 (status & SR0_EVENT_MASK) == SR0_RETRANSMIT_DONE ||
643 (status & SR0_EVENT_MASK) == SR0_TRANSMIT_NO_CRC_DONE) {
644 int tx_status;
645 outb(CR0_STATUS_1, ioaddr);
646 tx_status = inw(ioaddr);
647 /* It's undocumented, but tx_status seems to match the i82586. */
648 if (tx_status & TX_OK) {
649 znet->stats.tx_packets++;
650 znet->stats.collisions += tx_status & TX_NCOL_MASK;
651 } else {
652 if (tx_status & (TX_LOST_CTS | TX_LOST_CRS))
653 znet->stats.tx_carrier_errors++;
654 if (tx_status & TX_UND_RUN)
655 znet->stats.tx_fifo_errors++;
656 if (!(tx_status & TX_HRT_BEAT))
657 znet->stats.tx_heartbeat_errors++;
658 if (tx_status & TX_MAX_COL)
659 znet->stats.tx_aborted_errors++;
660 /* ...and the catch-all. */
661 if ((tx_status | (TX_LOST_CRS | TX_LOST_CTS | TX_UND_RUN | TX_HRT_BEAT | TX_MAX_COL)) != (TX_LOST_CRS | TX_LOST_CTS | TX_UND_RUN | TX_HRT_BEAT | TX_MAX_COL))
662 znet->stats.tx_errors++;
664 /* Transceiver may be stuck if cable
665 * was removed while emiting a
666 * packet. Flip it off, then on to
667 * reset it. This is very empirical,
668 * but it seems to work. */
670 znet_transceiver_power (dev, 0);
671 znet_transceiver_power (dev, 1);
672 }
673 netif_wake_queue (dev);
674 }
676 if ((status & SR0_RECEPTION) ||
677 (status & SR0_EVENT_MASK) == SR0_STOP_REG_HIT) {
678 znet_rx(dev);
679 }
680 /* Clear the interrupts we've handled. */
681 outb(CR0_INT_ACK, ioaddr);
682 } while (boguscnt--);
684 spin_unlock (&znet->lock);
686 return IRQ_RETVAL(handled);
687 }
689 static void znet_rx(struct net_device *dev)
690 {
691 struct znet_private *znet = dev->priv;
692 int ioaddr = dev->base_addr;
693 int boguscount = 1;
694 short next_frame_end_offset = 0; /* Offset of next frame start. */
695 short *cur_frame_end;
696 short cur_frame_end_offset;
698 outb(CR0_STATUS_2, ioaddr);
699 cur_frame_end_offset = inw(ioaddr);
701 if (cur_frame_end_offset == znet->rx_cur - znet->rx_start) {
702 printk(KERN_WARNING "%s: Interrupted, but nothing to receive, offset %03x.\n",
703 dev->name, cur_frame_end_offset);
704 return;
705 }
707 /* Use same method as the Crynwr driver: construct a forward list in
708 the same area of the backwards links we now have. This allows us to
709 pass packets to the upper layers in the order they were received --
710 important for fast-path sequential operations. */
711 while (znet->rx_start + cur_frame_end_offset != znet->rx_cur
712 && ++boguscount < 5) {
713 unsigned short hi_cnt, lo_cnt, hi_status, lo_status;
714 int count, status;
716 if (cur_frame_end_offset < 4) {
717 /* Oh no, we have a special case: the frame trailer wraps around
718 the end of the ring buffer. We've saved space at the end of
719 the ring buffer for just this problem. */
720 memcpy(znet->rx_end, znet->rx_start, 8);
721 cur_frame_end_offset += (RX_BUF_SIZE/2);
722 }
723 cur_frame_end = znet->rx_start + cur_frame_end_offset - 4;
725 lo_status = *cur_frame_end++;
726 hi_status = *cur_frame_end++;
727 status = ((hi_status & 0xff) << 8) + (lo_status & 0xff);
728 lo_cnt = *cur_frame_end++;
729 hi_cnt = *cur_frame_end++;
730 count = ((hi_cnt & 0xff) << 8) + (lo_cnt & 0xff);
732 if (znet_debug > 5)
733 printk(KERN_DEBUG "Constructing trailer at location %03x, %04x %04x %04x %04x"
734 " count %#x status %04x.\n",
735 cur_frame_end_offset<<1, lo_status, hi_status, lo_cnt, hi_cnt,
736 count, status);
737 cur_frame_end[-4] = status;
738 cur_frame_end[-3] = next_frame_end_offset;
739 cur_frame_end[-2] = count;
740 next_frame_end_offset = cur_frame_end_offset;
741 cur_frame_end_offset -= ((count + 1)>>1) + 3;
742 if (cur_frame_end_offset < 0)
743 cur_frame_end_offset += RX_BUF_SIZE/2;
744 };
746 /* Now step forward through the list. */
747 do {
748 ushort *this_rfp_ptr = znet->rx_start + next_frame_end_offset;
749 int status = this_rfp_ptr[-4];
750 int pkt_len = this_rfp_ptr[-2];
752 if (znet_debug > 5)
753 printk(KERN_DEBUG "Looking at trailer ending at %04x status %04x length %03x"
754 " next %04x.\n", next_frame_end_offset<<1, status, pkt_len,
755 this_rfp_ptr[-3]<<1);
756 /* Once again we must assume that the i82586 docs apply. */
757 if ( ! (status & RX_RCV_OK)) { /* There was an error. */
758 znet->stats.rx_errors++;
759 if (status & RX_CRC_ERR) znet->stats.rx_crc_errors++;
760 if (status & RX_ALG_ERR) znet->stats.rx_frame_errors++;
761 #if 0
762 if (status & 0x0200) znet->stats.rx_over_errors++; /* Wrong. */
763 if (status & 0x0100) znet->stats.rx_fifo_errors++;
764 #else
765 /* maz : Wild guess... */
766 if (status & RX_OVRRUN) znet->stats.rx_over_errors++;
767 #endif
768 if (status & RX_SRT_FRM) znet->stats.rx_length_errors++;
769 } else if (pkt_len > 1536) {
770 znet->stats.rx_length_errors++;
771 } else {
772 /* Malloc up new buffer. */
773 struct sk_buff *skb;
775 skb = dev_alloc_skb(pkt_len);
776 if (skb == NULL) {
777 if (znet_debug)
778 printk(KERN_WARNING "%s: Memory squeeze, dropping packet.\n", dev->name);
779 znet->stats.rx_dropped++;
780 break;
781 }
782 skb->dev = dev;
784 if (&znet->rx_cur[(pkt_len+1)>>1] > znet->rx_end) {
785 int semi_cnt = (znet->rx_end - znet->rx_cur)<<1;
786 memcpy(skb_put(skb,semi_cnt), znet->rx_cur, semi_cnt);
787 memcpy(skb_put(skb,pkt_len-semi_cnt), znet->rx_start,
788 pkt_len - semi_cnt);
789 } else {
790 memcpy(skb_put(skb,pkt_len), znet->rx_cur, pkt_len);
791 if (znet_debug > 6) {
792 unsigned int *packet = (unsigned int *) skb->data;
793 printk(KERN_DEBUG "Packet data is %08x %08x %08x %08x.\n", packet[0],
794 packet[1], packet[2], packet[3]);
795 }
796 }
797 skb->protocol=eth_type_trans(skb,dev);
798 netif_rx(skb);
799 dev->last_rx = jiffies;
800 znet->stats.rx_packets++;
801 znet->stats.rx_bytes += pkt_len;
802 }
803 znet->rx_cur = this_rfp_ptr;
804 if (znet->rx_cur >= znet->rx_end)
805 znet->rx_cur -= RX_BUF_SIZE/2;
806 update_stop_hit(ioaddr, (znet->rx_cur - znet->rx_start)<<1);
807 next_frame_end_offset = this_rfp_ptr[-3];
808 if (next_frame_end_offset == 0) /* Read all the frames? */
809 break; /* Done for now */
810 this_rfp_ptr = znet->rx_start + next_frame_end_offset;
811 } while (--boguscount);
813 /* If any worth-while packets have been received, dev_rint()
814 has done a mark_bh(INET_BH) for us and will work on them
815 when we get to the bottom-half routine. */
816 return;
817 }
819 /* The inverse routine to znet_open(). */
820 static int znet_close(struct net_device *dev)
821 {
822 int ioaddr = dev->base_addr;
824 netif_stop_queue (dev);
826 outb(OP0_RESET, ioaddr); /* CMD0_RESET */
828 if (znet_debug > 1)
829 printk(KERN_DEBUG "%s: Shutting down ethercard.\n", dev->name);
830 /* Turn off transceiver power. */
831 znet_transceiver_power (dev, 0);
833 znet_release_resources (dev);
835 return 0;
836 }
838 /* Get the current statistics. This may be called with the card open or
839 closed. */
840 static struct net_device_stats *net_get_stats(struct net_device *dev)
841 {
842 struct znet_private *znet = dev->priv;
844 return &znet->stats;
845 }
847 static void show_dma(struct net_device *dev)
848 {
849 short ioaddr = dev->base_addr;
850 unsigned char stat = inb (ioaddr);
851 struct znet_private *znet = dev->priv;
852 unsigned long flags;
853 short dma_port = ((znet->tx_dma&3)<<2) + IO_DMA2_BASE;
854 unsigned addr = inb(dma_port);
855 short residue;
857 addr |= inb(dma_port) << 8;
858 residue = get_dma_residue(znet->tx_dma);
860 if (znet_debug > 1) {
861 flags=claim_dma_lock();
862 printk(KERN_DEBUG "Stat:%02x Addr: %04x cnt:%3x\n",
863 stat, addr<<1, residue);
864 release_dma_lock(flags);
865 }
866 }
868 /* Initialize the hardware. We have to do this when the board is open()ed
869 or when we come out of suspend mode. */
870 static void hardware_init(struct net_device *dev)
871 {
872 unsigned long flags;
873 short ioaddr = dev->base_addr;
874 struct znet_private *znet = dev->priv;
876 znet->rx_cur = znet->rx_start;
877 znet->tx_cur = znet->tx_start;
879 /* Reset the chip, and start it up. */
880 outb(OP0_RESET, ioaddr);
882 flags=claim_dma_lock();
883 disable_dma(znet->rx_dma); /* reset by an interrupting task. */
884 clear_dma_ff(znet->rx_dma);
885 set_dma_mode(znet->rx_dma, DMA_RX_MODE);
886 set_dma_addr(znet->rx_dma, (unsigned int) znet->rx_start);
887 set_dma_count(znet->rx_dma, RX_BUF_SIZE);
888 enable_dma(znet->rx_dma);
889 /* Now set up the Tx channel. */
890 disable_dma(znet->tx_dma);
891 clear_dma_ff(znet->tx_dma);
892 set_dma_mode(znet->tx_dma, DMA_TX_MODE);
893 set_dma_addr(znet->tx_dma, (unsigned int) znet->tx_start);
894 set_dma_count(znet->tx_dma, znet->tx_buf_len<<1);
895 enable_dma(znet->tx_dma);
896 release_dma_lock(flags);
898 if (znet_debug > 1)
899 printk(KERN_DEBUG "%s: Initializing the i82593, rx buf %p tx buf %p\n",
900 dev->name, znet->rx_start,znet->tx_start);
901 /* Do an empty configure command, just like the Crynwr driver. This
902 resets to chip to its default values. */
903 *znet->tx_cur++ = 0;
904 *znet->tx_cur++ = 0;
905 show_dma(dev);
906 outb(OP0_CONFIGURE | CR0_CHNL, ioaddr);
908 znet_set_multicast_list (dev);
910 *znet->tx_cur++ = 6;
911 memcpy(znet->tx_cur, dev->dev_addr, 6);
912 znet->tx_cur += 3;
913 show_dma(dev);
914 outb(OP0_IA_SETUP | CR0_CHNL, ioaddr);
915 show_dma(dev);
917 update_stop_hit(ioaddr, 8192);
918 if (znet_debug > 1) printk(KERN_DEBUG "enabling Rx.\n");
919 outb(OP0_RCV_ENABLE, ioaddr);
920 netif_start_queue (dev);
921 }
923 static void update_stop_hit(short ioaddr, unsigned short rx_stop_offset)
924 {
925 outb(OP0_SWIT_TO_PORT_1 | CR0_CHNL, ioaddr);
926 if (znet_debug > 5)
927 printk(KERN_DEBUG "Updating stop hit with value %02x.\n",
928 (rx_stop_offset >> 6) | CR1_STOP_REG_UPDATE);
929 outb((rx_stop_offset >> 6) | CR1_STOP_REG_UPDATE, ioaddr);
930 outb(OP1_SWIT_TO_PORT_0, ioaddr);
931 }
933 static __exit void znet_cleanup (void)
934 {
935 if (znet_dev) {
936 struct znet_private *znet = znet_dev->priv;
938 unregister_netdev (znet_dev);
939 kfree (znet->rx_start);
940 kfree (znet->tx_start);
941 free_netdev (znet_dev);
942 }
943 }
945 module_init (znet_probe);
946 module_exit (znet_cleanup);