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_reserve(skb, 2);
 114                         eth_copy_and_sum(skb, buf, desc->pkt_length, 0);
 115                         skb_put(skb, desc->pkt_length);
 116                         skb->protocol = eth_type_trans(skb, nds[desc->channel]);
 117
 118                         skb->dev->last_rx = jiffies;
 119
 120                         netif_receive_skb(skb);
 121                 }
 122
 123 err:
 124                 ixp2000_reg_write(RING_RX_PENDING, _desc);
 125                 dev->quota--;
 126                 (*budget)--;
 127         }
 128
 129         return 1;
 130 }
 131
 132 /* dev always points to nds[0].  */
 133 static int ixpdev_poll(struct net_device *dev, int *budget)
 134 {
 135         /* @@@ Have to stop polling when nds[0] is administratively
 136          * downed while we are polling.  */
 137         do {
 138                 ixp2000_reg_write(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0x00ff);
 139
 140                 if (ixpdev_rx(dev, budget))
 141                         return 1;
 142         } while (ixp2000_reg_read(IXP2000_IRQ_THD_RAW_STATUS_A_0) & 0x00ff);
 143
 144         netif_rx_complete(dev);
 145         ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0x00ff);
 146
 147         return 0;
 148 }
 149
 150 static void ixpdev_tx_complete(void)
 151 {
 152         int channel;
 153         u32 wake;
 154
 155         wake = 0;
 156         while (1) {
 157                 struct ixpdev_priv *ip;
 158                 u32 desc;
 159                 int entry;
 160
 161                 desc = ixp2000_reg_read(RING_TX_DONE);
 162                 if (desc == 0)
 163                         break;
 164
 165                 /* @@@ Check whether entries come back in order.  */
 166                 entry = (desc - TX_BUF_DESC_BASE) / sizeof(struct ixpdev_tx_desc);
 167                 channel = tx_desc[entry].channel;
 168
 169                 if (channel < 0 || channel >= nds_count) {
 170                         printk(KERN_ERR "ixp2000: txcomp channel index "
 171                                         "out of bounds (%d, %.8i, %d)\n",
 172                                         channel, (unsigned int)desc, entry);
 173                         continue;
 174                 }
 175
 176                 ip = netdev_priv(nds[channel]);
 177                 if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
 178                         wake |= 1 << channel;
 179                 ip->tx_queue_entries--;
 180         }
 181
 182         for (channel = 0; wake != 0; channel++) {
 183                 if (wake & (1 << channel)) {
 184                         netif_wake_queue(nds[channel]);
 185                         wake &= ~(1 << channel);
 186                 }
 187         }
 188 }
 189
 190 static irqreturn_t ixpdev_interrupt(int irq, void *dev_id)
 191 {
 192         u32 status;
 193
 194         status = ixp2000_reg_read(IXP2000_IRQ_THD_STATUS_A_0);
 195         if (status == 0)
 196                 return IRQ_NONE;
 197
 198         /*
 199          * Any of the eight receive units signaled RX?
 200          */
 201         if (status & 0x00ff) {
 202                 ixp2000_reg_wrb(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0x00ff);
 203                 if (likely(__netif_rx_schedule_prep(nds[0]))) {
 204                         __netif_rx_schedule(nds[0]);
 205                 } else {
 206                         printk(KERN_CRIT "ixp2000: irq while polling!!\n");
 207                 }
 208         }
 209
 210         /*
 211          * Any of the eight transmit units signaled TXdone?
 212          */
 213         if (status & 0xff00) {
 214                 ixp2000_reg_wrb(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0xff00);
 215                 ixpdev_tx_complete();
 216         }
 217
 218         return IRQ_HANDLED;
 219 }
 220
 221 #ifdef CONFIG_NET_POLL_CONTROLLER
 222 static void ixpdev_poll_controller(struct net_device *dev)
 223 {
 224         disable_irq(IRQ_IXP2000_THDA0);
 225         ixpdev_interrupt(IRQ_IXP2000_THDA0, dev, NULL);
 226         enable_irq(IRQ_IXP2000_THDA0);
 227 }
 228 #endif
 229
 230 static int ixpdev_open(struct net_device *dev)
 231 {
 232         struct ixpdev_priv *ip = netdev_priv(dev);
 233         int err;
 234
 235         if (!nds_open++) {
 236                 err = request_irq(IRQ_IXP2000_THDA0, ixpdev_interrupt,
 237                                         IRQF_SHARED, "ixp2000_eth", nds);
 238                 if (err) {
 239                         nds_open--;
 240                         return err;
 241                 }
 242
 243                 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0xffff);
 244         }
 245
 246         set_port_admin_status(ip->channel, 1);
 247         netif_start_queue(dev);
 248
 249         return 0;
 250 }
 251
 252 static int ixpdev_close(struct net_device *dev)
 253 {
 254         struct ixpdev_priv *ip = netdev_priv(dev);
 255
 256         netif_stop_queue(dev);
 257         set_port_admin_status(ip->channel, 0);
 258
 259         if (!--nds_open) {
 260                 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0xffff);
 261                 free_irq(IRQ_IXP2000_THDA0, nds);
 262         }
 263
 264         return 0;
 265 }
 266
 267 struct net_device *ixpdev_alloc(int channel, int sizeof_priv)
 268 {
 269         struct net_device *dev;
 270         struct ixpdev_priv *ip;
 271
 272         dev = alloc_etherdev(sizeof_priv);
 273         if (dev == NULL)
 274                 return NULL;
 275
 276         dev->hard_start_xmit = ixpdev_xmit;
 277         dev->poll = ixpdev_poll;
 278         dev->open = ixpdev_open;
 279         dev->stop = ixpdev_close;
 280 #ifdef CONFIG_NET_POLL_CONTROLLER
 281         dev->poll_controller = ixpdev_poll_controller;
 282 #endif
 283
 284         dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
 285         dev->weight = 64;
 286
 287         ip = netdev_priv(dev);
 288         ip->channel = channel;
 289         ip->tx_queue_entries = 0;
 290
 291         return dev;
 292 }
 293
 294 int ixpdev_init(int __nds_count, struct net_device **__nds,
 295                 void (*__set_port_admin_status)(int port, int up))
 296 {
 297         int i;
 298         int err;
 299
 300         BUILD_BUG_ON(RX_BUF_COUNT > 192 || TX_BUF_COUNT > 192);
 301
 302         printk(KERN_INFO "IXP2000 MSF ethernet driver %s\n", DRV_MODULE_VERSION);
 303
 304         nds_count = __nds_count;
 305         nds = __nds;
 306         set_port_admin_status = __set_port_admin_status;
 307
 308         for (i = 0; i < RX_BUF_COUNT; i++) {
 309                 void *buf;
 310
 311                 buf = (void *)get_zeroed_page(GFP_KERNEL);
 312                 if (buf == NULL) {
 313                         err = -ENOMEM;
 314                         while (--i >= 0)
 315                                 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 316                         goto err_out;
 317                 }
 318                 rx_desc[i].buf_addr = virt_to_phys(buf);
 319                 rx_desc[i].buf_length = PAGE_SIZE;
 320         }
 321
 322         /* @@@ Maybe we shouldn't be preallocating TX buffers.  */
 323         for (i = 0; i < TX_BUF_COUNT; i++) {
 324                 void *buf;
 325
 326                 buf = (void *)get_zeroed_page(GFP_KERNEL);
 327                 if (buf == NULL) {
 328                         err = -ENOMEM;
 329                         while (--i >= 0)
 330                                 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 331                         goto err_free_rx;
 332                 }
 333                 tx_desc[i].buf_addr = virt_to_phys(buf);
 334         }
 335
 336         /* 256 entries, ring status set means 'empty', base address 0x0000.  */
 337         ixp2000_reg_write(RING_RX_PENDING_BASE, 0x44000000);
 338         ixp2000_reg_write(RING_RX_PENDING_HEAD, 0x00000000);
 339         ixp2000_reg_write(RING_RX_PENDING_TAIL, 0x00000000);
 340
 341         /* 256 entries, ring status set means 'full', base address 0x0400.  */
 342         ixp2000_reg_write(RING_RX_DONE_BASE, 0x40000400);
 343         ixp2000_reg_write(RING_RX_DONE_HEAD, 0x00000000);
 344         ixp2000_reg_write(RING_RX_DONE_TAIL, 0x00000000);
 345
 346         for (i = 0; i < RX_BUF_COUNT; i++) {
 347                 ixp2000_reg_write(RING_RX_PENDING,
 348                         RX_BUF_DESC_BASE + (i * sizeof(struct ixpdev_rx_desc)));
 349         }
 350
 351         ixp2000_uengine_load(0, &ixp2400_rx);
 352         ixp2000_uengine_start_contexts(0, 0xff);
 353
 354         /* 256 entries, ring status set means 'empty', base address 0x0800.  */
 355         ixp2000_reg_write(RING_TX_PENDING_BASE, 0x44000800);
 356         ixp2000_reg_write(RING_TX_PENDING_HEAD, 0x00000000);
 357         ixp2000_reg_write(RING_TX_PENDING_TAIL, 0x00000000);
 358
 359         /* 256 entries, ring status set means 'full', base address 0x0c00.  */
 360         ixp2000_reg_write(RING_TX_DONE_BASE, 0x40000c00);
 361         ixp2000_reg_write(RING_TX_DONE_HEAD, 0x00000000);
 362         ixp2000_reg_write(RING_TX_DONE_TAIL, 0x00000000);
 363
 364         ixp2000_uengine_load(1, &ixp2400_tx);
 365         ixp2000_uengine_start_contexts(1, 0xff);
 366
 367         for (i = 0; i < nds_count; i++) {
 368                 err = register_netdev(nds[i]);
 369                 if (err) {
 370                         while (--i >= 0)
 371                                 unregister_netdev(nds[i]);
 372                         goto err_free_tx;
 373                 }
 374         }
 375
 376         for (i = 0; i < nds_count; i++) {
 377                 printk(KERN_INFO "%s: IXP2000 MSF ethernet (port %d), "
 378                         "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x.\n", nds[i]->name, i,
 379                         nds[i]->dev_addr[0], nds[i]->dev_addr[1],
 380                         nds[i]->dev_addr[2], nds[i]->dev_addr[3],
 381                         nds[i]->dev_addr[4], nds[i]->dev_addr[5]);
 382         }
 383
 384         return 0;
 385
 386 err_free_tx:
 387         for (i = 0; i < TX_BUF_COUNT; i++)
 388                 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 389
 390 err_free_rx:
 391         for (i = 0; i < RX_BUF_COUNT; i++)
 392                 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 393
 394 err_out:
 395         return err;
 396 }
 397
 398 void ixpdev_deinit(void)
 399 {
 400         int i;
 401
 402         /* @@@ Flush out pending packets.  */
 403
 404         for (i = 0; i < nds_count; i++)
 405                 unregister_netdev(nds[i]);
 406
 407         ixp2000_uengine_stop_contexts(1, 0xff);
 408         ixp2000_uengine_stop_contexts(0, 0xff);
 409         ixp2000_uengine_reset(0x3);
 410
 411         for (i = 0; i < TX_BUF_COUNT; i++)
 412                 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 413
 414         for (i = 0; i < RX_BUF_COUNT; i++)
 415                 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 416 }