drivers/net/caif/caif_shmcore.c

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
   4  * Authors:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com,
   5  *           Daniel Martensson / daniel.martensson@stericsson.com
   6  * License terms: GNU General Public License (GPL) version 2
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ":" fmt
  10
  11 #include <linux/spinlock.h>
  12 #include <linux/sched.h>
  13 #include <linux/list.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/if_arp.h>
  16 #include <linux/io.h>
  17
  18 #include <net/caif/caif_device.h>
  19 #include <net/caif/caif_shm.h>
  20
  21 #define NR_TX_BUF               6
  22 #define NR_RX_BUF               6
  23 #define TX_BUF_SZ               0x2000
  24 #define RX_BUF_SZ               0x2000
  25
  26 #define CAIF_NEEDED_HEADROOM    32
  27
  28 #define CAIF_FLOW_ON            1
  29 #define CAIF_FLOW_OFF           0
  30
  31 #define LOW_WATERMARK           3
  32 #define HIGH_WATERMARK          4
  33
  34 /* Maximum number of CAIF buffers per shared memory buffer. */
  35 #define SHM_MAX_FRMS_PER_BUF    10
  36
  37 /*
  38  * Size in bytes of the descriptor area
  39  * (With end of descriptor signalling)
  40  */
  41 #define SHM_CAIF_DESC_SIZE      ((SHM_MAX_FRMS_PER_BUF + 1) * \
  42                                         sizeof(struct shm_pck_desc))
  43
  44 /*
  45  * Offset to the first CAIF frame within a shared memory buffer.
  46  * Aligned on 32 bytes.
  47  */
  48 #define SHM_CAIF_FRM_OFS        (SHM_CAIF_DESC_SIZE + (SHM_CAIF_DESC_SIZE % 32))
  49
  50 /* Number of bytes for CAIF shared memory header. */
  51 #define SHM_HDR_LEN             1
  52
  53 /* Number of padding bytes for the complete CAIF frame. */
  54 #define SHM_FRM_PAD_LEN         4
  55
  56 #define CAIF_MAX_MTU            4096
  57
  58 #define SHM_SET_FULL(x) (((x+1) & 0x0F) << 0)
  59 #define SHM_GET_FULL(x) (((x >> 0) & 0x0F) - 1)
  60
  61 #define SHM_SET_EMPTY(x)        (((x+1) & 0x0F) << 4)
  62 #define SHM_GET_EMPTY(x)        (((x >> 4) & 0x0F) - 1)
  63
  64 #define SHM_FULL_MASK           (0x0F << 0)
  65 #define SHM_EMPTY_MASK          (0x0F << 4)
  66
  67 struct shm_pck_desc {
  68         /*
  69          * Offset from start of shared memory area to start of
  70          * shared memory CAIF frame.
  71          */
  72         u32 frm_ofs;
  73         u32 frm_len;
  74 };
  75
  76 struct buf_list {
  77         unsigned char *desc_vptr;
  78         u32 phy_addr;
  79         u32 index;
  80         u32 len;
  81         u32 frames;
  82         u32 frm_ofs;
  83         struct list_head list;
  84 };
  85
  86 struct shm_caif_frm {
  87         /* Number of bytes of padding before the CAIF frame. */
  88         u8 hdr_ofs;
  89 };
  90
  91 struct shmdrv_layer {
  92         /* caif_dev_common must always be first in the structure*/
  93         struct caif_dev_common cfdev;
  94
  95         u32 shm_tx_addr;
  96         u32 shm_rx_addr;
  97         u32 shm_base_addr;
  98         u32 tx_empty_available;
  99         spinlock_t lock;
 100
 101         struct list_head tx_empty_list;
 102         struct list_head tx_pend_list;
 103         struct list_head tx_full_list;
 104         struct list_head rx_empty_list;
 105         struct list_head rx_pend_list;
 106         struct list_head rx_full_list;
 107
 108         struct workqueue_struct *pshm_tx_workqueue;
 109         struct workqueue_struct *pshm_rx_workqueue;
 110
 111         struct work_struct shm_tx_work;
 112         struct work_struct shm_rx_work;
 113
 114         struct sk_buff_head sk_qhead;
 115         struct shmdev_layer *pshm_dev;
 116 };
 117
 118 static int shm_netdev_open(struct net_device *shm_netdev)
 119 {
 120         netif_wake_queue(shm_netdev);
 121         return 0;
 122 }
 123
 124 static int shm_netdev_close(struct net_device *shm_netdev)
 125 {
 126         netif_stop_queue(shm_netdev);
 127         return 0;
 128 }
 129
 130 int caif_shmdrv_rx_cb(u32 mbx_msg, void *priv)
 131 {
 132         struct buf_list *pbuf;
 133         struct shmdrv_layer *pshm_drv;
 134         struct list_head *pos;
 135         u32 avail_emptybuff = 0;
 136         unsigned long flags = 0;
 137
 138         pshm_drv = priv;
 139
 140         /* Check for received buffers. */
 141         if (mbx_msg & SHM_FULL_MASK) {
 142                 int idx;
 143
 144                 spin_lock_irqsave(&pshm_drv->lock, flags);
 145
 146                 /* Check whether we have any outstanding buffers. */
 147                 if (list_empty(&pshm_drv->rx_empty_list)) {
 148
 149                         /* Release spin lock. */
 150                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 151
 152                         /* We print even in IRQ context... */
 153                         pr_warn("No empty Rx buffers to fill: "
 154                                         "mbx_msg:%x\n", mbx_msg);
 155
 156                         /* Bail out. */
 157                         goto err_sync;
 158                 }
 159
 160                 pbuf =
 161                         list_entry(pshm_drv->rx_empty_list.next,
 162                                         struct buf_list, list);
 163                 idx = pbuf->index;
 164
 165                 /* Check buffer synchronization. */
 166                 if (idx != SHM_GET_FULL(mbx_msg)) {
 167
 168                         /* We print even in IRQ context... */
 169                         pr_warn(
 170                         "phyif_shm_mbx_msg_cb: RX full out of sync:"
 171                         " idx:%d, msg:%x SHM_GET_FULL(mbx_msg):%x\n",
 172                                 idx, mbx_msg, SHM_GET_FULL(mbx_msg));
 173
 174                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 175
 176                         /* Bail out. */
 177                         goto err_sync;
 178                 }
 179
 180                 list_del_init(&pbuf->list);
 181                 list_add_tail(&pbuf->list, &pshm_drv->rx_full_list);
 182
 183                 spin_unlock_irqrestore(&pshm_drv->lock, flags);
 184
 185                 /* Schedule RX work queue. */
 186                 if (!work_pending(&pshm_drv->shm_rx_work))
 187                         queue_work(pshm_drv->pshm_rx_workqueue,
 188                                                 &pshm_drv->shm_rx_work);
 189         }
 190
 191         /* Check for emptied buffers. */
 192         if (mbx_msg & SHM_EMPTY_MASK) {
 193                 int idx;
 194
 195                 spin_lock_irqsave(&pshm_drv->lock, flags);
 196
 197                 /* Check whether we have any outstanding buffers. */
 198                 if (list_empty(&pshm_drv->tx_full_list)) {
 199
 200                         /* We print even in IRQ context... */
 201                         pr_warn("No TX to empty: msg:%x\n", mbx_msg);
 202
 203                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 204
 205                         /* Bail out. */
 206                         goto err_sync;
 207                 }
 208
 209                 pbuf =
 210                         list_entry(pshm_drv->tx_full_list.next,
 211                                         struct buf_list, list);
 212                 idx = pbuf->index;
 213
 214                 /* Check buffer synchronization. */
 215                 if (idx != SHM_GET_EMPTY(mbx_msg)) {
 216
 217                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 218
 219                         /* We print even in IRQ context... */
 220                         pr_warn("TX empty "
 221                                 "out of sync:idx:%d, msg:%x\n", idx, mbx_msg);
 222
 223                         /* Bail out. */
 224                         goto err_sync;
 225                 }
 226                 list_del_init(&pbuf->list);
 227
 228                 /* Reset buffer parameters. */
 229                 pbuf->frames = 0;
 230                 pbuf->frm_ofs = SHM_CAIF_FRM_OFS;
 231
 232                 list_add_tail(&pbuf->list, &pshm_drv->tx_empty_list);
 233
 234                 /* Check the available no. of buffers in the empty list */
 235                 list_for_each(pos, &pshm_drv->tx_empty_list)
 236                         avail_emptybuff++;
 237
 238                 /* Check whether we have to wake up the transmitter. */
 239                 if ((avail_emptybuff > HIGH_WATERMARK) &&
 240                                         (!pshm_drv->tx_empty_available)) {
 241                         pshm_drv->tx_empty_available = 1;
 242                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 243                         pshm_drv->cfdev.flowctrl
 244                                         (pshm_drv->pshm_dev->pshm_netdev,
 245                                                                 CAIF_FLOW_ON);
 246
 247
 248                         /* Schedule the work queue. if required */
 249                         if (!work_pending(&pshm_drv->shm_tx_work))
 250                                 queue_work(pshm_drv->pshm_tx_workqueue,
 251                                                         &pshm_drv->shm_tx_work);
 252                 } else
 253                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 254         }
 255
 256         return 0;
 257
 258 err_sync:
 259         return -EIO;
 260 }
 261
 262 static void shm_rx_work_func(struct work_struct *rx_work)
 263 {
 264         struct shmdrv_layer *pshm_drv;
 265         struct buf_list *pbuf;
 266         unsigned long flags = 0;
 267         struct sk_buff *skb;
 268         char *p;
 269         int ret;
 270
 271         pshm_drv = container_of(rx_work, struct shmdrv_layer, shm_rx_work);
 272
 273         while (1) {
 274
 275                 struct shm_pck_desc *pck_desc;
 276
 277                 spin_lock_irqsave(&pshm_drv->lock, flags);
 278
 279                 /* Check for received buffers. */
 280                 if (list_empty(&pshm_drv->rx_full_list)) {
 281                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 282                         break;
 283                 }
 284
 285                 pbuf =
 286                         list_entry(pshm_drv->rx_full_list.next, struct buf_list,
 287                                         list);
 288                 list_del_init(&pbuf->list);
 289                 spin_unlock_irqrestore(&pshm_drv->lock, flags);
 290
 291                 /* Retrieve pointer to start of the packet descriptor area. */
 292                 pck_desc = (struct shm_pck_desc *) pbuf->desc_vptr;
 293
 294                 /*
 295                  * Check whether descriptor contains a CAIF shared memory
 296                  * frame.
 297                  */
 298                 while (pck_desc->frm_ofs) {
 299                         unsigned int frm_buf_ofs;
 300                         unsigned int frm_pck_ofs;
 301                         unsigned int frm_pck_len;
 302                         /*
 303                          * Check whether offset is within buffer limits
 304                          * (lower).
 305                          */
 306                         if (pck_desc->frm_ofs <
 307                                 (pbuf->phy_addr - pshm_drv->shm_base_addr))
 308                                 break;
 309                         /*
 310                          * Check whether offset is within buffer limits
 311                          * (higher).
 312                          */
 313                         if (pck_desc->frm_ofs >
 314                                 ((pbuf->phy_addr - pshm_drv->shm_base_addr) +
 315                                         pbuf->len))
 316                                 break;
 317
 318                         /* Calculate offset from start of buffer. */
 319                         frm_buf_ofs =
 320                                 pck_desc->frm_ofs - (pbuf->phy_addr -
 321                                                 pshm_drv->shm_base_addr);
 322
 323                         /*
 324                          * Calculate offset and length of CAIF packet while
 325                          * taking care of the shared memory header.
 326                          */
 327                         frm_pck_ofs =
 328                                 frm_buf_ofs + SHM_HDR_LEN +
 329                                 (*(pbuf->desc_vptr + frm_buf_ofs));
 330                         frm_pck_len =
 331                                 (pck_desc->frm_len - SHM_HDR_LEN -
 332                                 (*(pbuf->desc_vptr + frm_buf_ofs)));
 333
 334                         /* Check whether CAIF packet is within buffer limits */
 335                         if ((frm_pck_ofs + pck_desc->frm_len) > pbuf->len)
 336                                 break;
 337
 338                         /* Get a suitable CAIF packet and copy in data. */
 339                         skb = netdev_alloc_skb(pshm_drv->pshm_dev->pshm_netdev,
 340                                                         frm_pck_len + 1);
 341
 342                         if (skb == NULL) {
 343                                 pr_info("OOM: Try next frame in descriptor\n");
 344                                 break;
 345                         }
 346
 347                         p = skb_put(skb, frm_pck_len);
 348                         memcpy(p, pbuf->desc_vptr + frm_pck_ofs, frm_pck_len);
 349
 350                         skb->protocol = htons(ETH_P_CAIF);
 351                         skb_reset_mac_header(skb);
 352                         skb->dev = pshm_drv->pshm_dev->pshm_netdev;
 353
 354                         /* Push received packet up the stack. */
 355                         ret = netif_rx_ni(skb);
 356
 357                         if (!ret) {
 358                                 pshm_drv->pshm_dev->pshm_netdev->stats.
 359                                                                 rx_packets++;
 360                                 pshm_drv->pshm_dev->pshm_netdev->stats.
 361                                                 rx_bytes += pck_desc->frm_len;
 362                         } else
 363                                 ++pshm_drv->pshm_dev->pshm_netdev->stats.
 364                                                                 rx_dropped;
 365                         /* Move to next packet descriptor. */
 366                         pck_desc++;
 367                 }
 368
 369                 spin_lock_irqsave(&pshm_drv->lock, flags);
 370                 list_add_tail(&pbuf->list, &pshm_drv->rx_pend_list);
 371
 372                 spin_unlock_irqrestore(&pshm_drv->lock, flags);
 373
 374         }
 375
 376         /* Schedule the work queue. if required */
 377         if (!work_pending(&pshm_drv->shm_tx_work))
 378                 queue_work(pshm_drv->pshm_tx_workqueue, &pshm_drv->shm_tx_work);
 379
 380 }
 381
 382 static void shm_tx_work_func(struct work_struct *tx_work)
 383 {
 384         u32 mbox_msg;
 385         unsigned int frmlen, avail_emptybuff, append = 0;
 386         unsigned long flags = 0;
 387         struct buf_list *pbuf = NULL;
 388         struct shmdrv_layer *pshm_drv;
 389         struct shm_caif_frm *frm;
 390         struct sk_buff *skb;
 391         struct shm_pck_desc *pck_desc;
 392         struct list_head *pos;
 393
 394         pshm_drv = container_of(tx_work, struct shmdrv_layer, shm_tx_work);
 395
 396         do {
 397                 /* Initialize mailbox message. */
 398                 mbox_msg = 0x00;
 399                 avail_emptybuff = 0;
 400
 401                 spin_lock_irqsave(&pshm_drv->lock, flags);
 402
 403                 /* Check for pending receive buffers. */
 404                 if (!list_empty(&pshm_drv->rx_pend_list)) {
 405
 406                         pbuf = list_entry(pshm_drv->rx_pend_list.next,
 407                                                 struct buf_list, list);
 408
 409                         list_del_init(&pbuf->list);
 410                         list_add_tail(&pbuf->list, &pshm_drv->rx_empty_list);
 411                         /*
 412                          * Value index is never changed,
 413                          * so read access should be safe.
 414                          */
 415                         mbox_msg |= SHM_SET_EMPTY(pbuf->index);
 416                 }
 417
 418                 skb = skb_peek(&pshm_drv->sk_qhead);
 419
 420                 if (skb == NULL)
 421                         goto send_msg;
 422                 /* Check the available no. of buffers in the empty list */
 423                 list_for_each(pos, &pshm_drv->tx_empty_list)
 424                         avail_emptybuff++;
 425
 426                 if ((avail_emptybuff < LOW_WATERMARK) &&
 427                                         pshm_drv->tx_empty_available) {
 428                         /* Update blocking condition. */
 429                         pshm_drv->tx_empty_available = 0;
 430                         spin_unlock_irqrestore(&pshm_drv->lock, flags);
 431                         pshm_drv->cfdev.flowctrl
 432                                         (pshm_drv->pshm_dev->pshm_netdev,
 433                                         CAIF_FLOW_OFF);
 434                         spin_lock_irqsave(&pshm_drv->lock, flags);
 435                 }
 436                 /*
 437                  * We simply return back to the caller if we do not have space
 438                  * either in Tx pending list or Tx empty list. In this case,
 439                  * we hold the received skb in the skb list, waiting to
 440                  * be transmitted once Tx buffers become available
 441                  */
 442                 if (list_empty(&pshm_drv->tx_empty_list))
 443                         goto send_msg;
 444
 445                 /* Get the first free Tx buffer. */
 446                 pbuf = list_entry(pshm_drv->tx_empty_list.next,
 447                                                 struct buf_list, list);
 448                 do {
 449                         if (append) {
 450                                 skb = skb_peek(&pshm_drv->sk_qhead);
 451                                 if (skb == NULL)
 452                                         break;
 453                         }
 454
 455                         frm = (struct shm_caif_frm *)
 456                                         (pbuf->desc_vptr + pbuf->frm_ofs);
 457
 458                         frm->hdr_ofs = 0;
 459                         frmlen = 0;
 460                         frmlen += SHM_HDR_LEN + frm->hdr_ofs + skb->len;
 461
 462                         /* Add tail padding if needed. */
 463                         if (frmlen % SHM_FRM_PAD_LEN)
 464                                 frmlen += SHM_FRM_PAD_LEN -
 465                                                 (frmlen % SHM_FRM_PAD_LEN);
 466
 467                         /*
 468                          * Verify that packet, header and additional padding
 469                          * can fit within the buffer frame area.
 470                          */
 471                         if (frmlen >= (pbuf->len - pbuf->frm_ofs))
 472                                 break;
 473
 474                         if (!append) {
 475                                 list_del_init(&pbuf->list);
 476                                 append = 1;
 477                         }
 478
 479                         skb = skb_dequeue(&pshm_drv->sk_qhead);
 480                         if (skb == NULL)
 481                                 break;
 482                         /* Copy in CAIF frame. */
 483                         skb_copy_bits(skb, 0, pbuf->desc_vptr +
 484                                         pbuf->frm_ofs + SHM_HDR_LEN +
 485                                                 frm->hdr_ofs, skb->len);
 486
 487                         pshm_drv->pshm_dev->pshm_netdev->stats.tx_packets++;
 488                         pshm_drv->pshm_dev->pshm_netdev->stats.tx_bytes +=
 489                                                                         frmlen;
 490                         dev_kfree_skb_irq(skb);
 491
 492                         /* Fill in the shared memory packet descriptor area. */
 493                         pck_desc = (struct shm_pck_desc *) (pbuf->desc_vptr);
 494                         /* Forward to current frame. */
 495                         pck_desc += pbuf->frames;
 496                         pck_desc->frm_ofs = (pbuf->phy_addr -
 497                                                 pshm_drv->shm_base_addr) +
 498                                                                 pbuf->frm_ofs;
 499                         pck_desc->frm_len = frmlen;
 500                         /* Terminate packet descriptor area. */
 501                         pck_desc++;
 502                         pck_desc->frm_ofs = 0;
 503                         /* Update buffer parameters. */
 504                         pbuf->frames++;
 505                         pbuf->frm_ofs += frmlen + (frmlen % 32);
 506
 507                 } while (pbuf->frames < SHM_MAX_FRMS_PER_BUF);
 508
 509                 /* Assign buffer as full. */
 510                 list_add_tail(&pbuf->list, &pshm_drv->tx_full_list);
 511                 append = 0;
 512                 mbox_msg |= SHM_SET_FULL(pbuf->index);
 513 send_msg:
 514                 spin_unlock_irqrestore(&pshm_drv->lock, flags);
 515
 516                 if (mbox_msg)
 517                         pshm_drv->pshm_dev->pshmdev_mbxsend
 518                                         (pshm_drv->pshm_dev->shm_id, mbox_msg);
 519         } while (mbox_msg);
 520 }
 521
 522 static int shm_netdev_tx(struct sk_buff *skb, struct net_device *shm_netdev)
 523 {
 524         struct shmdrv_layer *pshm_drv;
 525
 526         pshm_drv = netdev_priv(shm_netdev);
 527
 528         skb_queue_tail(&pshm_drv->sk_qhead, skb);
 529
 530         /* Schedule Tx work queue. for deferred processing of skbs*/
 531         if (!work_pending(&pshm_drv->shm_tx_work))
 532                 queue_work(pshm_drv->pshm_tx_workqueue, &pshm_drv->shm_tx_work);
 533
 534         return 0;
 535 }
 536
 537 static const struct net_device_ops netdev_ops = {
 538         .ndo_open = shm_netdev_open,
 539         .ndo_stop = shm_netdev_close,
 540         .ndo_start_xmit = shm_netdev_tx,
 541 };
 542
 543 static void shm_netdev_setup(struct net_device *pshm_netdev)
 544 {
 545         struct shmdrv_layer *pshm_drv;
 546         pshm_netdev->netdev_ops = &netdev_ops;
 547
 548         pshm_netdev->mtu = CAIF_MAX_MTU;
 549         pshm_netdev->type = ARPHRD_CAIF;
 550         pshm_netdev->hard_header_len = CAIF_NEEDED_HEADROOM;
 551         pshm_netdev->tx_queue_len = 0;
 552         pshm_netdev->destructor = free_netdev;
 553
 554         pshm_drv = netdev_priv(pshm_netdev);
 555
 556         /* Initialize structures in a clean state. */
 557         memset(pshm_drv, 0, sizeof(struct shmdrv_layer));
 558
 559         pshm_drv->cfdev.link_select = CAIF_LINK_LOW_LATENCY;
 560 }
 561
 562 int caif_shmcore_probe(struct shmdev_layer *pshm_dev)
 563 {
 564         int result, j;
 565         struct shmdrv_layer *pshm_drv = NULL;
 566
 567         pshm_dev->pshm_netdev = alloc_netdev(sizeof(struct shmdrv_layer),
 568                                                 "cfshm%d", shm_netdev_setup);
 569         if (!pshm_dev->pshm_netdev)
 570                 return -ENOMEM;
 571
 572         pshm_drv = netdev_priv(pshm_dev->pshm_netdev);
 573         pshm_drv->pshm_dev = pshm_dev;
 574
 575         /*
 576          * Initialization starts with the verification of the
 577          * availability of MBX driver by calling its setup function.
 578          * MBX driver must be available by this time for proper
 579          * functioning of SHM driver.
 580          */
 581         if ((pshm_dev->pshmdev_mbxsetup
 582                                 (caif_shmdrv_rx_cb, pshm_dev, pshm_drv)) != 0) {
 583                 pr_warn("Could not config. SHM Mailbox,"
 584                                 " Bailing out.....\n");
 585                 free_netdev(pshm_dev->pshm_netdev);
 586                 return -ENODEV;
 587         }
 588
 589         skb_queue_head_init(&pshm_drv->sk_qhead);
 590
 591         pr_info("SHM DEVICE[%d] PROBED BY DRIVER, NEW SHM DRIVER"
 592                         " INSTANCE AT pshm_drv =0x%p\n",
 593                         pshm_drv->pshm_dev->shm_id, pshm_drv);
 594
 595         if (pshm_dev->shm_total_sz <
 596                         (NR_TX_BUF * TX_BUF_SZ + NR_RX_BUF * RX_BUF_SZ)) {
 597
 598                 pr_warn("ERROR, Amount of available"
 599                                 " Phys. SHM cannot accommodate current SHM "
 600                                 "driver configuration, Bailing out ...\n");
 601                 free_netdev(pshm_dev->pshm_netdev);
 602                 return -ENOMEM;
 603         }
 604
 605         pshm_drv->shm_base_addr = pshm_dev->shm_base_addr;
 606         pshm_drv->shm_tx_addr = pshm_drv->shm_base_addr;
 607
 608         if (pshm_dev->shm_loopback)
 609                 pshm_drv->shm_rx_addr = pshm_drv->shm_tx_addr;
 610         else
 611                 pshm_drv->shm_rx_addr = pshm_dev->shm_base_addr +
 612                                                 (NR_TX_BUF * TX_BUF_SZ);
 613
 614         spin_lock_init(&pshm_drv->lock);
 615         INIT_LIST_HEAD(&pshm_drv->tx_empty_list);
 616         INIT_LIST_HEAD(&pshm_drv->tx_pend_list);
 617         INIT_LIST_HEAD(&pshm_drv->tx_full_list);
 618
 619         INIT_LIST_HEAD(&pshm_drv->rx_empty_list);
 620         INIT_LIST_HEAD(&pshm_drv->rx_pend_list);
 621         INIT_LIST_HEAD(&pshm_drv->rx_full_list);
 622
 623         INIT_WORK(&pshm_drv->shm_tx_work, shm_tx_work_func);
 624         INIT_WORK(&pshm_drv->shm_rx_work, shm_rx_work_func);
 625
 626         pshm_drv->pshm_tx_workqueue =
 627                                 create_singlethread_workqueue("shm_tx_work");
 628         pshm_drv->pshm_rx_workqueue =
 629                                 create_singlethread_workqueue("shm_rx_work");
 630
 631         for (j = 0; j < NR_TX_BUF; j++) {
 632                 struct buf_list *tx_buf =
 633                                 kmalloc(sizeof(struct buf_list), GFP_KERNEL);
 634
 635                 if (tx_buf == NULL) {
 636                         free_netdev(pshm_dev->pshm_netdev);
 637                         return -ENOMEM;
 638                 }
 639                 tx_buf->index = j;
 640                 tx_buf->phy_addr = pshm_drv->shm_tx_addr + (TX_BUF_SZ * j);
 641                 tx_buf->len = TX_BUF_SZ;
 642                 tx_buf->frames = 0;
 643                 tx_buf->frm_ofs = SHM_CAIF_FRM_OFS;
 644
 645                 if (pshm_dev->shm_loopback)
 646                         tx_buf->desc_vptr = (unsigned char *)tx_buf->phy_addr;
 647                 else
 648                         /*
 649                          * FIXME: the result of ioremap is not a pointer - arnd
 650                          */
 651                         tx_buf->desc_vptr =
 652                                         ioremap(tx_buf->phy_addr, TX_BUF_SZ);
 653
 654                 list_add_tail(&tx_buf->list, &pshm_drv->tx_empty_list);
 655         }
 656
 657         for (j = 0; j < NR_RX_BUF; j++) {
 658                 struct buf_list *rx_buf =
 659                                 kmalloc(sizeof(struct buf_list), GFP_KERNEL);
 660
 661                 if (rx_buf == NULL) {
 662                         free_netdev(pshm_dev->pshm_netdev);
 663                         return -ENOMEM;
 664                 }
 665                 rx_buf->index = j;
 666                 rx_buf->phy_addr = pshm_drv->shm_rx_addr + (RX_BUF_SZ * j);
 667                 rx_buf->len = RX_BUF_SZ;
 668
 669                 if (pshm_dev->shm_loopback)
 670                         rx_buf->desc_vptr = (unsigned char *)rx_buf->phy_addr;
 671                 else
 672                         rx_buf->desc_vptr =
 673                                         ioremap(rx_buf->phy_addr, RX_BUF_SZ);
 674                 list_add_tail(&rx_buf->list, &pshm_drv->rx_empty_list);
 675         }
 676
 677         pshm_drv->tx_empty_available = 1;
 678         result = register_netdev(pshm_dev->pshm_netdev);
 679         if (result)
 680                 pr_warn("ERROR[%d], SHM could not, "
 681                         "register with NW FRMWK Bailing out ...\n", result);
 682
 683         return result;
 684 }
 685
 686 void caif_shmcore_remove(struct net_device *pshm_netdev)
 687 {
 688         struct buf_list *pbuf;
 689         struct shmdrv_layer *pshm_drv = NULL;
 690
 691         pshm_drv = netdev_priv(pshm_netdev);
 692
 693         while (!(list_empty(&pshm_drv->tx_pend_list))) {
 694                 pbuf =
 695                         list_entry(pshm_drv->tx_pend_list.next,
 696                                         struct buf_list, list);
 697
 698                 list_del(&pbuf->list);
 699                 kfree(pbuf);
 700         }
 701
 702         while (!(list_empty(&pshm_drv->tx_full_list))) {
 703                 pbuf =
 704                         list_entry(pshm_drv->tx_full_list.next,
 705                                         struct buf_list, list);
 706                 list_del(&pbuf->list);
 707                 kfree(pbuf);
 708         }
 709
 710         while (!(list_empty(&pshm_drv->tx_empty_list))) {
 711                 pbuf =
 712                         list_entry(pshm_drv->tx_empty_list.next,
 713                                         struct buf_list, list);
 714                 list_del(&pbuf->list);
 715                 kfree(pbuf);
 716         }
 717
 718         while (!(list_empty(&pshm_drv->rx_full_list))) {
 719                 pbuf =
 720                         list_entry(pshm_drv->tx_full_list.next,
 721                                 struct buf_list, list);
 722                 list_del(&pbuf->list);
 723                 kfree(pbuf);
 724         }
 725
 726         while (!(list_empty(&pshm_drv->rx_pend_list))) {
 727                 pbuf =
 728                         list_entry(pshm_drv->tx_pend_list.next,
 729                                 struct buf_list, list);
 730                 list_del(&pbuf->list);
 731                 kfree(pbuf);
 732         }
 733
 734         while (!(list_empty(&pshm_drv->rx_empty_list))) {
 735                 pbuf =
 736                         list_entry(pshm_drv->rx_empty_list.next,
 737                                 struct buf_list, list);
 738                 list_del(&pbuf->list);
 739                 kfree(pbuf);
 740         }
 741
 742         /* Destroy work queues. */
 743         destroy_workqueue(pshm_drv->pshm_tx_workqueue);
 744         destroy_workqueue(pshm_drv->pshm_rx_workqueue);
 745
 746         unregister_netdev(pshm_netdev);
 747 }