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/config.h>
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/init.h>
  18 #include <linux/moduleparam.h>
  19 #include <asm/hardware/uengine.h>
  20 #include <asm/mach-types.h>
  21 #include <asm/io.h>
  22 #include "ixp2400_rx.ucode"
  23 #include "ixp2400_tx.ucode"
  24 #include "ixpdev_priv.h"
  25 #include "ixpdev.h"
  26
  27 #define DRV_MODULE_VERSION      "0.2"
  28
  29 static int nds_count;
  30 static struct net_device **nds;
  31 static int nds_open;
  32 static void (*set_port_admin_status)(int port, int up);
  33
  34 static struct ixpdev_rx_desc * const rx_desc =
  35         (struct ixpdev_rx_desc *)(IXP2000_SRAM0_VIRT_BASE + RX_BUF_DESC_BASE);
  36 static struct ixpdev_tx_desc * const tx_desc =
  37         (struct ixpdev_tx_desc *)(IXP2000_SRAM0_VIRT_BASE + TX_BUF_DESC_BASE);
  38 static int tx_pointer;
  39
  40
  41 static int ixpdev_xmit(struct sk_buff *skb, struct net_device *dev)
  42 {
  43         struct ixpdev_priv *ip = netdev_priv(dev);
  44         struct ixpdev_tx_desc *desc;
  45         int entry;
  46
  47         if (unlikely(skb->len > PAGE_SIZE)) {
  48                 /* @@@ Count drops.  */
  49                 dev_kfree_skb(skb);
  50                 return 0;
  51         }
  52
  53         entry = tx_pointer;
  54         tx_pointer = (tx_pointer + 1) % TX_BUF_COUNT;
  55
  56         desc = tx_desc + entry;
  57         desc->pkt_length = skb->len;
  58         desc->channel = ip->channel;
  59
  60         skb_copy_and_csum_dev(skb, phys_to_virt(desc->buf_addr));
  61         dev_kfree_skb(skb);
  62
  63         ixp2000_reg_write(RING_TX_PENDING,
  64                 TX_BUF_DESC_BASE + (entry * sizeof(struct ixpdev_tx_desc)));
  65
  66         dev->trans_start = jiffies;
  67
  68         local_irq_disable();
  69         ip->tx_queue_entries++;
  70         if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
  71                 netif_stop_queue(dev);
  72         local_irq_enable();
  73
  74         return 0;
  75 }
  76
  77
  78 static int ixpdev_rx(struct net_device *dev, int *budget)
  79 {
  80         while (*budget > 0) {
  81                 struct ixpdev_rx_desc *desc;
  82                 struct sk_buff *skb;
  83                 void *buf;
  84                 u32 _desc;
  85
  86                 _desc = ixp2000_reg_read(RING_RX_DONE);
  87                 if (_desc == 0)
  88                         return 0;
  89
  90                 desc = rx_desc +
  91                         ((_desc - RX_BUF_DESC_BASE) / sizeof(struct ixpdev_rx_desc));
  92                 buf = phys_to_virt(desc->buf_addr);
  93
  94                 if (desc->pkt_length < 4 || desc->pkt_length > PAGE_SIZE) {
  95                         printk(KERN_ERR "ixp2000: rx err, length %d\n",
  96                                         desc->pkt_length);
  97                         goto err;
  98                 }
  99
 100                 if (desc->channel < 0 || desc->channel >= nds_count) {
 101                         printk(KERN_ERR "ixp2000: rx err, channel %d\n",
 102                                         desc->channel);
 103                         goto err;
 104                 }
 105
 106                 /* @@@ Make FCS stripping configurable.  */
 107                 desc->pkt_length -= 4;
 108
 109                 if (unlikely(!netif_running(nds[desc->channel])))
 110                         goto err;
 111
 112                 skb = dev_alloc_skb(desc->pkt_length + 2);
 113                 if (likely(skb != NULL)) {
 114                         skb->dev = nds[desc->channel];
 115                         skb_reserve(skb, 2);
 116                         eth_copy_and_sum(skb, buf, desc->pkt_length, 0);
 117                         skb_put(skb, desc->pkt_length);
 118                         skb->protocol = eth_type_trans(skb, skb->dev);
 119
 120                         skb->dev->last_rx = jiffies;
 121
 122                         netif_receive_skb(skb);
 123                 }
 124
 125 err:
 126                 ixp2000_reg_write(RING_RX_PENDING, _desc);
 127                 dev->quota--;
 128                 (*budget)--;
 129         }
 130
 131         return 1;
 132 }
 133
 134 /* dev always points to nds[0].  */
 135 static int ixpdev_poll(struct net_device *dev, int *budget)
 136 {
 137         /* @@@ Have to stop polling when nds[0] is administratively
 138          * downed while we are polling.  */
 139         do {
 140                 ixp2000_reg_write(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0x00ff);
 141
 142                 if (ixpdev_rx(dev, budget))
 143                         return 1;
 144         } while (ixp2000_reg_read(IXP2000_IRQ_THD_RAW_STATUS_A_0) & 0x00ff);
 145
 146         netif_rx_complete(dev);
 147         ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0x00ff);
 148
 149         return 0;
 150 }
 151
 152 static void ixpdev_tx_complete(void)
 153 {
 154         int channel;
 155         u32 wake;
 156
 157         wake = 0;
 158         while (1) {
 159                 struct ixpdev_priv *ip;
 160                 u32 desc;
 161                 int entry;
 162
 163                 desc = ixp2000_reg_read(RING_TX_DONE);
 164                 if (desc == 0)
 165                         break;
 166
 167                 /* @@@ Check whether entries come back in order.  */
 168                 entry = (desc - TX_BUF_DESC_BASE) / sizeof(struct ixpdev_tx_desc);
 169                 channel = tx_desc[entry].channel;
 170
 171                 if (channel < 0 || channel >= nds_count) {
 172                         printk(KERN_ERR "ixp2000: txcomp channel index "
 173                                         "out of bounds (%d, %.8i, %d)\n",
 174                                         channel, (unsigned int)desc, entry);
 175                         continue;
 176                 }
 177
 178                 ip = netdev_priv(nds[channel]);
 179                 if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
 180                         wake |= 1 << channel;
 181                 ip->tx_queue_entries--;
 182         }
 183
 184         for (channel = 0; wake != 0; channel++) {
 185                 if (wake & (1 << channel)) {
 186                         netif_wake_queue(nds[channel]);
 187                         wake &= ~(1 << channel);
 188                 }
 189         }
 190 }
 191
 192 static irqreturn_t ixpdev_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 193 {
 194         u32 status;
 195
 196         status = ixp2000_reg_read(IXP2000_IRQ_THD_STATUS_A_0);
 197         if (status == 0)
 198                 return IRQ_NONE;
 199
 200         /*
 201          * Any of the eight receive units signaled RX?
 202          */
 203         if (status & 0x00ff) {
 204                 ixp2000_reg_wrb(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0x00ff);
 205                 if (likely(__netif_rx_schedule_prep(nds[0]))) {
 206                         __netif_rx_schedule(nds[0]);
 207                 } else {
 208                         printk(KERN_CRIT "ixp2000: irq while polling!!\n");
 209                 }
 210         }
 211
 212         /*
 213          * Any of the eight transmit units signaled TXdone?
 214          */
 215         if (status & 0xff00) {
 216                 ixp2000_reg_wrb(IXP2000_IRQ_THD_RAW_STATUS_A_0, 0xff00);
 217                 ixpdev_tx_complete();
 218         }
 219
 220         return IRQ_HANDLED;
 221 }
 222
 223 #ifdef CONFIG_NET_POLL_CONTROLLER
 224 static void ixpdev_poll_controller(struct net_device *dev)
 225 {
 226         disable_irq(IRQ_IXP2000_THDA0);
 227         ixpdev_interrupt(IRQ_IXP2000_THDA0, dev, NULL);
 228         enable_irq(IRQ_IXP2000_THDA0);
 229 }
 230 #endif
 231
 232 static int ixpdev_open(struct net_device *dev)
 233 {
 234         struct ixpdev_priv *ip = netdev_priv(dev);
 235         int err;
 236
 237         if (!nds_open++) {
 238                 err = request_irq(IRQ_IXP2000_THDA0, ixpdev_interrupt,
 239                                         SA_SHIRQ, "ixp2000_eth", nds);
 240                 if (err) {
 241                         nds_open--;
 242                         return err;
 243                 }
 244
 245                 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_SET_A_0, 0xffff);
 246         }
 247
 248         set_port_admin_status(ip->channel, 1);
 249         netif_start_queue(dev);
 250
 251         return 0;
 252 }
 253
 254 static int ixpdev_close(struct net_device *dev)
 255 {
 256         struct ixpdev_priv *ip = netdev_priv(dev);
 257
 258         netif_stop_queue(dev);
 259         set_port_admin_status(ip->channel, 0);
 260
 261         if (!--nds_open) {
 262                 ixp2000_reg_write(IXP2000_IRQ_THD_ENABLE_CLEAR_A_0, 0xffff);
 263                 free_irq(IRQ_IXP2000_THDA0, nds);
 264         }
 265
 266         return 0;
 267 }
 268
 269 struct net_device *ixpdev_alloc(int channel, int sizeof_priv)
 270 {
 271         struct net_device *dev;
 272         struct ixpdev_priv *ip;
 273
 274         dev = alloc_etherdev(sizeof_priv);
 275         if (dev == NULL)
 276                 return NULL;
 277
 278         dev->hard_start_xmit = ixpdev_xmit;
 279         dev->poll = ixpdev_poll;
 280         dev->open = ixpdev_open;
 281         dev->stop = ixpdev_close;
 282 #ifdef CONFIG_NET_POLL_CONTROLLER
 283         dev->poll_controller = ixpdev_poll_controller;
 284 #endif
 285
 286         dev->features |= NETIF_F_SG | NETIF_F_HW_CSUM;
 287         dev->weight = 64;
 288
 289         ip = netdev_priv(dev);
 290         ip->channel = channel;
 291         ip->tx_queue_entries = 0;
 292
 293         return dev;
 294 }
 295
 296 int ixpdev_init(int __nds_count, struct net_device **__nds,
 297                 void (*__set_port_admin_status)(int port, int up))
 298 {
 299         int i;
 300         int err;
 301
 302         if (RX_BUF_COUNT > 192 || TX_BUF_COUNT > 192) {
 303                 static void __too_many_rx_or_tx_buffers(void);
 304                 __too_many_rx_or_tx_buffers();
 305         }
 306
 307         printk(KERN_INFO "IXP2000 MSF ethernet driver %s\n", DRV_MODULE_VERSION);
 308
 309         nds_count = __nds_count;
 310         nds = __nds;
 311         set_port_admin_status = __set_port_admin_status;
 312
 313         for (i = 0; i < RX_BUF_COUNT; i++) {
 314                 void *buf;
 315
 316                 buf = (void *)get_zeroed_page(GFP_KERNEL);
 317                 if (buf == NULL) {
 318                         err = -ENOMEM;
 319                         while (--i >= 0)
 320                                 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 321                         goto err_out;
 322                 }
 323                 rx_desc[i].buf_addr = virt_to_phys(buf);
 324                 rx_desc[i].buf_length = PAGE_SIZE;
 325         }
 326
 327         /* @@@ Maybe we shouldn't be preallocating TX buffers.  */
 328         for (i = 0; i < TX_BUF_COUNT; i++) {
 329                 void *buf;
 330
 331                 buf = (void *)get_zeroed_page(GFP_KERNEL);
 332                 if (buf == NULL) {
 333                         err = -ENOMEM;
 334                         while (--i >= 0)
 335                                 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 336                         goto err_free_rx;
 337                 }
 338                 tx_desc[i].buf_addr = virt_to_phys(buf);
 339         }
 340
 341         /* 256 entries, ring status set means 'empty', base address 0x0000.  */
 342         ixp2000_reg_write(RING_RX_PENDING_BASE, 0x44000000);
 343         ixp2000_reg_write(RING_RX_PENDING_HEAD, 0x00000000);
 344         ixp2000_reg_write(RING_RX_PENDING_TAIL, 0x00000000);
 345
 346         /* 256 entries, ring status set means 'full', base address 0x0400.  */
 347         ixp2000_reg_write(RING_RX_DONE_BASE, 0x40000400);
 348         ixp2000_reg_write(RING_RX_DONE_HEAD, 0x00000000);
 349         ixp2000_reg_write(RING_RX_DONE_TAIL, 0x00000000);
 350
 351         for (i = 0; i < RX_BUF_COUNT; i++) {
 352                 ixp2000_reg_write(RING_RX_PENDING,
 353                         RX_BUF_DESC_BASE + (i * sizeof(struct ixpdev_rx_desc)));
 354         }
 355
 356         ixp2000_uengine_load(0, &ixp2400_rx);
 357         ixp2000_uengine_start_contexts(0, 0xff);
 358
 359         /* 256 entries, ring status set means 'empty', base address 0x0800.  */
 360         ixp2000_reg_write(RING_TX_PENDING_BASE, 0x44000800);
 361         ixp2000_reg_write(RING_TX_PENDING_HEAD, 0x00000000);
 362         ixp2000_reg_write(RING_TX_PENDING_TAIL, 0x00000000);
 363
 364         /* 256 entries, ring status set means 'full', base address 0x0c00.  */
 365         ixp2000_reg_write(RING_TX_DONE_BASE, 0x40000c00);
 366         ixp2000_reg_write(RING_TX_DONE_HEAD, 0x00000000);
 367         ixp2000_reg_write(RING_TX_DONE_TAIL, 0x00000000);
 368
 369         ixp2000_uengine_load(1, &ixp2400_tx);
 370         ixp2000_uengine_start_contexts(1, 0xff);
 371
 372         for (i = 0; i < nds_count; i++) {
 373                 err = register_netdev(nds[i]);
 374                 if (err) {
 375                         while (--i >= 0)
 376                                 unregister_netdev(nds[i]);
 377                         goto err_free_tx;
 378                 }
 379         }
 380
 381         for (i = 0; i < nds_count; i++) {
 382                 printk(KERN_INFO "%s: IXP2000 MSF ethernet (port %d), "
 383                         "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x.\n", nds[i]->name, i,
 384                         nds[i]->dev_addr[0], nds[i]->dev_addr[1],
 385                         nds[i]->dev_addr[2], nds[i]->dev_addr[3],
 386                         nds[i]->dev_addr[4], nds[i]->dev_addr[5]);
 387         }
 388
 389         return 0;
 390
 391 err_free_tx:
 392         for (i = 0; i < TX_BUF_COUNT; i++)
 393                 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 394
 395 err_free_rx:
 396         for (i = 0; i < RX_BUF_COUNT; i++)
 397                 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 398
 399 err_out:
 400         return err;
 401 }
 402
 403 void ixpdev_deinit(void)
 404 {
 405         int i;
 406
 407         /* @@@ Flush out pending packets.  */
 408
 409         for (i = 0; i < nds_count; i++)
 410                 unregister_netdev(nds[i]);
 411
 412         ixp2000_uengine_stop_contexts(1, 0xff);
 413         ixp2000_uengine_stop_contexts(0, 0xff);
 414         ixp2000_uengine_reset(0x3);
 415
 416         for (i = 0; i < TX_BUF_COUNT; i++)
 417                 free_page((unsigned long)phys_to_virt(tx_desc[i].buf_addr));
 418
 419         for (i = 0; i < RX_BUF_COUNT; i++)
 420                 free_page((unsigned long)phys_to_virt(rx_desc[i].buf_addr));
 421 }