linux/drivers/net/ixp2000/ixpdev.c
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   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 processed, int budget)
  78{
  79        while (processed < budget) {
  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                        skb_copy_to_linear_data(skb, buf, desc->pkt_length);
 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
 123err:
 124                ixp2000_reg_write(RING_RX_PENDING, _desc);
 125                processed++;
 126        }
 127
 128        return processed;
 129}
 130
 131/* dev always points to nds[0].  */
 132static int ixpdev_poll(struct napi_struct *napi, int budget)
 133{
 134        struct ixpdev_priv *ip = container_of(napi, struct ixpdev_priv, napi);
 135        struct net_device *dev = ip->dev;
 136        int rx;
 137
 138        rx = 0;
 139        do {
 140                ixp2000_reg_write(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0x00ff);
 141
 142                rx = ixpdev_rx(dev, rx, budget);
 143                if (rx >= budget)
 144                        break;
 145        } while (ixp2000_reg_read(IXP2000_IRQ_THD_RAW_STATUS_A_0) & 0x00ff);
 146
 147        netif_rx_complete(dev, napi);
 148        ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0x00ff);
 149
 150        return rx;
 151}
 152
 153static void ixpdev_tx_complete(void)
 154{
 155        int channel;
 156        u32 wake;
 157
 158        wake = 0;
 159        while (1) {
 160                struct ixpdev_priv *ip;
 161                u32 desc;
 162                int entry;
 163
 164                desc = ixp2000_reg_read(RING_TX_DONE);
 165                if (desc == 0)
 166                        break;
 167
 168                /* @@@ Check whether entries come back in order.  */
 169                entry = (desc - TX_BUF_DESC_BASE) / sizeof(struct ixpdev_tx_desc);
 170                channel = tx_desc[entry].channel;
 171
 172                if (channel < 0 || channel >= nds_count) {
 173                        printk(KERN_ERR "ixp2000: txcomp channel index "
 174                                        "out of bounds (%d, %.8i, %d)\n",
 175                                        channel, (unsigned int)desc, entry);
 176                        continue;
 177                }
 178
 179                ip = netdev_priv(nds[channel]);
 180                if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
 181                        wake |= 1 << channel;
 182                ip->tx_queue_entries--;
 183        }
 184
 185        for (channel = 0; wake != 0; channel++) {
 186                if (wake & (1 << channel)) {
 187                        netif_wake_queue(nds[channel]);
 188                        wake &= ~(1 << channel);
 189                }
 190        }
 191}
 192
 193static irqreturn_t ixpdev_interrupt(int irq, void *dev_id)
 194{
 195        u32 status;
 196
 197        status = ixp2000_reg_read(IXP2000_IRQ_THD_STATUS_A_0);
 198        if (status == 0)
 199                return IRQ_NONE;
 200
 201        /*
 202         * Any of the eight receive units signaled RX?
 203         */
 204        if (status & 0x00ff) {
 205                struct net_device *dev = nds[0];
 206                struct ixpdev_priv *ip = netdev_priv(dev);
 207
 208                ixp2000_reg_wrb(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0x00ff);
 209                if (likely(napi_schedule_prep(&ip->napi))) {
 210                        __netif_rx_schedule(dev, &ip->napi);
 211                } else {
 212                        printk(KERN_CRIT "ixp2000: irq while polling!!\n");
 213                }
 214        }
 215
 216        /*
 217         * Any of the eight transmit units signaled TXdone?
 218         */
 219        if (status & 0xff00) {
 220                ixp2000_reg_wrb(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0xff00);
 221                ixpdev_tx_complete();
 222        }
 223
 224        return IRQ_HANDLED;
 225}
 226
 227#ifdef CONFIG_NET_POLL_CONTROLLER
 228static void ixpdev_poll_controller(struct net_device *dev)
 229{
 230        disable_irq(IRQ_IXP2000_THDA0);
 231        ixpdev_interrupt(IRQ_IXP2000_THDA0, dev);
 232        enable_irq(IRQ_IXP2000_THDA0);
 233}
 234#endif
 235
 236static int ixpdev_open(struct net_device *dev)
 237{
 238        struct ixpdev_priv *ip = netdev_priv(dev);
 239        int err;
 240
 241        napi_enable(&ip->napi);
 242        if (!nds_open++) {
 243                err = request_irq(IRQ_IXP2000_THDA0, ixpdev_interrupt,
 244                                        IRQF_SHARED, "ixp2000_eth", nds);
 245                if (err) {
 246                        nds_open--;
 247                        napi_disable(&ip->napi);
 248                        return err;
 249                }
 250
 251                ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0xffff);
 252        }
 253
 254        set_port_admin_status(ip->channel, 1);
 255        netif_start_queue(dev);
 256
 257        return 0;
 258}
 259
 260static int ixpdev_close(struct net_device *dev)
 261{
 262        struct ixpdev_priv *ip = netdev_priv(dev);
 263
 264        netif_stop_queue(dev);
 265        napi_disable(&ip->napi);
 266        set_port_admin_status(ip->channel, 0);
 267
 268        if (!--nds_open) {
 269                ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0xffff);
 270                free_irq(IRQ_IXP2000_THDA0, nds);
 271        }
 272
 273        return 0;
 274}
 275
 276struct net_device *ixpdev_alloc(int channel, int sizeof_priv)
 277{
 278        struct net_device *dev;
 279        struct ixpdev_priv *ip;
 280
 281        dev = alloc_etherdev(sizeof_priv);
 282        if (dev == NULL)
 283                return NULL;
 284
 285        dev->hard_start_xmit = ixpdev_xmit;
 286        dev->open = ixpdev_open;
 287        dev->stop = ixpdev_close;
 288#ifdef CONFIG_NET_POLL_CONTROLLER
 289        dev->poll_controller = ixpdev_poll_controller;
 290#endif
 291
 292        dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
 293
 294        ip = netdev_priv(dev);
 295        ip->dev = dev;
 296        netif_napi_add(dev, &ip->napi, ixpdev_poll, 64);
 297        ip->channel = channel;
 298        ip->tx_queue_entries = 0;
 299
 300        return dev;
 301}
 302
 303int ixpdev_init(int __nds_count, struct net_device **__nds,
 304                void (*__set_port_admin_status)(int port, int up))
 305{
 306        int i;
 307        int err;
 308
 309        BUILD_BUG_ON(RX_BUF_COUNT > 192 || TX_BUF_COUNT > 192);
 310
 311        printk(KERN_INFO "IXP2000 MSF ethernet driver %s\n", DRV_MODULE_VERSION);
 312
 313        nds_count = __nds_count;
 314        nds = __nds;
 315        set_port_admin_status = __set_port_admin_status;
 316
 317        for (i = 0; i < RX_BUF_COUNT; i++) {
 318                void *buf;
 319
 320                buf = (void *)get_zeroed_page(GFP_KERNEL);
 321                if (buf == NULL) {
 322                        err = -ENOMEM;
 323                        while (--i >= 0)
 324                                free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 325                        goto err_out;
 326                }
 327                rx_desc[i].buf_addr = virt_to_phys(buf);
 328                rx_desc[i].buf_length = PAGE_SIZE;
 329        }
 330
 331        /* @@@ Maybe we shouldn't be preallocating TX buffers.  */
 332        for (i = 0; i < TX_BUF_COUNT; i++) {
 333                void *buf;
 334
 335                buf = (void *)get_zeroed_page(GFP_KERNEL);
 336                if (buf == NULL) {
 337                        err = -ENOMEM;
 338                        while (--i >= 0)
 339                                free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 340                        goto err_free_rx;
 341                }
 342                tx_desc[i].buf_addr = virt_to_phys(buf);
 343        }
 344
 345        /* 256 entries, ring status set means 'empty', base address 0x0000.  */
 346        ixp2000_reg_write(RING_RX_PENDING_BASE, 0x44000000);
 347        ixp2000_reg_write(RING_RX_PENDING_HEAD, 0x00000000);
 348        ixp2000_reg_write(RING_RX_PENDING_TAIL, 0x00000000);
 349
 350        /* 256 entries, ring status set means 'full', base address 0x0400.  */
 351        ixp2000_reg_write(RING_RX_DONE_BASE, 0x40000400);
 352        ixp2000_reg_write(RING_RX_DONE_HEAD, 0x00000000);
 353        ixp2000_reg_write(RING_RX_DONE_TAIL, 0x00000000);
 354
 355        for (i = 0; i < RX_BUF_COUNT; i++) {
 356                ixp2000_reg_write(RING_RX_PENDING,
 357                        RX_BUF_DESC_BASE + (i * sizeof(struct ixpdev_rx_desc)));
 358        }
 359
 360        ixp2000_uengine_load(0, &ixp2400_rx);
 361        ixp2000_uengine_start_contexts(0, 0xff);
 362
 363        /* 256 entries, ring status set means 'empty', base address 0x0800.  */
 364        ixp2000_reg_write(RING_TX_PENDING_BASE, 0x44000800);
 365        ixp2000_reg_write(RING_TX_PENDING_HEAD, 0x00000000);
 366        ixp2000_reg_write(RING_TX_PENDING_TAIL, 0x00000000);
 367
 368        /* 256 entries, ring status set means 'full', base address 0x0c00.  */
 369        ixp2000_reg_write(RING_TX_DONE_BASE, 0x40000c00);
 370        ixp2000_reg_write(RING_TX_DONE_HEAD, 0x00000000);
 371        ixp2000_reg_write(RING_TX_DONE_TAIL, 0x00000000);
 372
 373        ixp2000_uengine_load(1, &ixp2400_tx);
 374        ixp2000_uengine_start_contexts(1, 0xff);
 375
 376        for (i = 0; i < nds_count; i++) {
 377                err = register_netdev(nds[i]);
 378                if (err) {
 379                        while (--i >= 0)
 380                                unregister_netdev(nds[i]);
 381                        goto err_free_tx;
 382                }
 383        }
 384
 385        for (i = 0; i < nds_count; i++) {
 386                printk(KERN_INFO "%s: IXP2000 MSF ethernet (port %d), "
 387                        "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x.\n", nds[i]->name, i,
 388                        nds[i]->dev_addr[0], nds[i]->dev_addr[1],
 389                        nds[i]->dev_addr[2], nds[i]->dev_addr[3],
 390                        nds[i]->dev_addr[4], nds[i]->dev_addr[5]);
 391        }
 392
 393        return 0;
 394
 395err_free_tx:
 396        for (i = 0; i < TX_BUF_COUNT; i++)
 397                free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 398
 399err_free_rx:
 400        for (i = 0; i < RX_BUF_COUNT; i++)
 401                free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 402
 403err_out:
 404        return err;
 405} 
 406
 407void ixpdev_deinit(void)
 408{
 409        int i;
 410
 411        /* @@@ Flush out pending packets.  */
 412
 413        for (i = 0; i < nds_count; i++)
 414                unregister_netdev(nds[i]);
 415
 416        ixp2000_uengine_stop_contexts(1, 0xff);
 417        ixp2000_uengine_stop_contexts(0, 0xff);
 418        ixp2000_uengine_reset(0x3);
 419
 420        for (i = 0; i < TX_BUF_COUNT; i++)
 421                free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 422
 423        for (i = 0; i < RX_BUF_COUNT; i++)
 424                free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 425}
 426