drivers/net/ixp2000/ixpdev.c

   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
  28 static int nds_count;
  29 static struct net_device **nds;
  30 static int nds_open;
  31 static void (*set_port_admin_status)(int port, int up);
  32
  33 static struct ixpdev_rx_desc * const rx_desc =
  34         (struct ixpdev_rx_desc *)(IXP2000_SRAM0_VIRT_BASE + RX_BUF_DESC_BASE);
  35 static struct ixpdev_tx_desc * const tx_desc =
  36         (struct ixpdev_tx_desc *)(IXP2000_SRAM0_VIRT_BASE + TX_BUF_DESC_BASE);
  37 static int tx_pointer;
  38
  39
  40 static 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
  77 static 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
 124 err:
 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].  */
 134 static 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
 151 static 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
 191 static irqreturn_t ixpdev_interrupt(int irq, void *dev_id)
 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
 223 static 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
 231 static 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
 253 static 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
 268 struct 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
 295 int 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
 387 err_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
 391 err_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
 395 err_out:
 396         return err;
 397 }
 398
 399 void 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 }