1 files changed, 732 insertions, 0 deletions

diff --git a/drivers/isdn/pcbit/layer2.c b/drivers/isdn/pcbit/layer2.c
new file mode 100644
index 000000000000..ba766930f088
--- /dev/null
+++ b/drivers/isdn/pcbit/layer2.c
@@ -0,0 +1,732 @@
+/*
+ * PCBIT-D low-layer interface
+ *
+ * Copyright (C) 1996 Universidade de Lisboa
+ *
+ * Written by Pedro Roque Marques (roque@di.fc.ul.pt)
+ *
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License, incorporated herein by reference.
+ */
+
+/*
+ * 19991203 - Fernando Carvalho - takion@superbofh.org
+ * Hacked to compile with egcs and run with current version of isdn modules
+*/
+
+/*
+ *        Based on documentation provided by Inesc:
+ *        - "Interface com bus do PC para o PCBIT e PCBIT-D", Inesc, Jan 93
+ */
+
+/*
+ *        TODO: better handling of errors
+ *              re-write/remove debug printks
+ */
+
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/mm.h>
+#include <linux/skbuff.h>
+
+#include <linux/isdnif.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+
+
+#include "pcbit.h"
+#include "layer2.h"
+#include "edss1.h"
+
+#undef DEBUG_FRAG
+
+
+
+/*
+ *  task queue struct
+ */
+
+
+
+/*
+ *  Layer 3 packet demultiplexer
+ *  drv.c
+ */
+
+extern void pcbit_l3_receive(struct pcbit_dev *dev, ulong msg,
+                             struct sk_buff *skb,
+                             ushort hdr_len, ushort refnum);
+
+/*
+ *  Prototypes
+ */
+
+void pcbit_deliver(void *data);
+static void pcbit_transmit(struct pcbit_dev *dev);
+
+static void pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack);
+
+static void pcbit_l2_error(struct pcbit_dev *dev);
+static void pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info);
+static void pcbit_l2_err_recover(unsigned long data);
+
+static void pcbit_firmware_bug(struct pcbit_dev *dev);
+
+static __inline__ void
+pcbit_sched_delivery(struct pcbit_dev *dev)
+{
+        schedule_work(&dev->qdelivery);
+}
+
+
+/*
+ *  Called from layer3
+ */
+
+int
+pcbit_l2_write(struct pcbit_dev *dev, ulong msg, ushort refnum,
+               struct sk_buff *skb, unsigned short hdr_len)
+{
+        struct frame_buf *frame,
+        *ptr;
+        unsigned long flags;
+
+        if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) {
+                dev_kfree_skb(skb);
+                return -1;
+        }
+        if ((frame = (struct frame_buf *) kmalloc(sizeof(struct frame_buf),
+                                                  GFP_ATOMIC)) == NULL) {
+                printk(KERN_WARNING "pcbit_2_write: kmalloc failed\n");
+                dev_kfree_skb(skb);
+                return -1;
+        }
+        frame->msg = msg;
+        frame->refnum = refnum;
+        frame->copied = 0;
+        frame->hdr_len = hdr_len;
+
+        if (skb)
+                frame->dt_len = skb->len - hdr_len;
+        else
+                frame->dt_len = 0;
+
+        frame->skb = skb;
+
+        frame->next = NULL;
+
+        spin_lock_irqsave(&dev->lock, flags);
+
+        if (dev->write_queue == NULL) {
+                dev->write_queue = frame;
+                spin_unlock_irqrestore(&dev->lock, flags);
+                pcbit_transmit(dev);
+        } else {
+                for (ptr = dev->write_queue; ptr->next; ptr = ptr->next);
+                ptr->next = frame;
+
+                spin_unlock_irqrestore(&dev->lock, flags);
+        }
+        return 0;
+}
+
+static __inline__ void
+pcbit_tx_update(struct pcbit_dev *dev, ushort len)
+{
+        u_char info;
+
+        dev->send_seq = (dev->send_seq + 1) % 8;
+
+        dev->fsize[dev->send_seq] = len;
+        info = 0;
+        info |= dev->rcv_seq << 3;
+        info |= dev->send_seq;
+
+        writeb(info, dev->sh_mem + BANK4);
+
+}
+
+/*
+ * called by interrupt service routine or by write_2
+ */
+
+static void
+pcbit_transmit(struct pcbit_dev *dev)
+{
+        struct frame_buf *frame = NULL;
+        unsigned char unacked;
+        int flen;               /* fragment frame length including all headers */
+        int free;
+        int count,
+         cp_len;
+        unsigned long flags;
+        unsigned short tt;
+
+        if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING)
+                return;
+
+        unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07;
+
+        spin_lock_irqsave(&dev->lock, flags);
+
+        if (dev->free > 16 && dev->write_queue && unacked < 7) {
+
+                if (!dev->w_busy)
+                        dev->w_busy = 1;
+                else {
+                        spin_unlock_irqrestore(&dev->lock, flags);
+                        return;
+                }
+
+
+                frame = dev->write_queue;
+                free = dev->free;
+
+                spin_unlock_irqrestore(&dev->lock, flags);
+
+                if (frame->copied == 0) {
+
+                        /* Type 0 frame */
+
+                        ulong   msg;
+
+                        if (frame->skb)
+                                flen = FRAME_HDR_LEN + PREHDR_LEN + frame->skb->len;
+                        else
+                                flen = FRAME_HDR_LEN + PREHDR_LEN;
+
+                        if (flen > free)
+                                flen = free;
+
+                        msg = frame->msg;
+
+                        /*
+                         *  Board level 2 header
+                         */
+
+                        pcbit_writew(dev, flen - FRAME_HDR_LEN);
+
+                        pcbit_writeb(dev, GET_MSG_CPU(msg));
+
+                        pcbit_writeb(dev, GET_MSG_PROC(msg));
+
+                        /* TH */
+                        pcbit_writew(dev, frame->hdr_len + PREHDR_LEN);
+
+                        /* TD */
+                        pcbit_writew(dev, frame->dt_len);
+
+
+                        /*
+                         *  Board level 3 fixed-header
+                         */
+
+                        /* LEN = TH */
+                        pcbit_writew(dev, frame->hdr_len + PREHDR_LEN);
+
+                        /* XX */
+                        pcbit_writew(dev, 0);
+
+                        /* C + S */
+                        pcbit_writeb(dev, GET_MSG_CMD(msg));
+                        pcbit_writeb(dev, GET_MSG_SCMD(msg));
+
+                        /* NUM */
+                        pcbit_writew(dev, frame->refnum);
+
+                        count = FRAME_HDR_LEN + PREHDR_LEN;
+                } else {
+                        /* Type 1 frame */
+
+                        flen = 2 + (frame->skb->len - frame->copied);
+
+                        if (flen > free)
+                                flen = free;
+
+                        /* TT */
+                        tt = ((ushort) (flen - 2)) | 0x8000U;   /* Type 1 */
+                        pcbit_writew(dev, tt);
+
+                        count = 2;
+                }
+
+                if (frame->skb) {
+                        cp_len = frame->skb->len - frame->copied;
+                        if (cp_len > flen - count)
+                                cp_len = flen - count;
+
+                        memcpy_topcbit(dev, frame->skb->data + frame->copied,
+                                       cp_len);
+                        frame->copied += cp_len;
+                }
+                /* bookkeeping */
+                dev->free -= flen;
+                pcbit_tx_update(dev, flen);
+
+                spin_lock_irqsave(&dev->lock, flags);
+
+                if (frame->skb == NULL || frame->copied == frame->skb->len) {
+
+                        dev->write_queue = frame->next;
+
+                        if (frame->skb != NULL) {
+                                /* free frame */
+                                dev_kfree_skb(frame->skb);
+                        }
+                        kfree(frame);
+                }
+                dev->w_busy = 0;
+                spin_unlock_irqrestore(&dev->lock, flags);
+        } else {
+                spin_unlock_irqrestore(&dev->lock, flags);
+#ifdef DEBUG
+                printk(KERN_DEBUG "unacked %d free %d write_queue %s\n",
+                     unacked, dev->free, dev->write_queue ? "not empty" :
+                       "empty");
+#endif
+        }
+}
+
+
+/*
+ *  deliver a queued frame to the upper layer
+ */
+
+void
+pcbit_deliver(void *data)
+{
+        struct frame_buf *frame;
+        unsigned long flags, msg;
+        struct pcbit_dev *dev = (struct pcbit_dev *) data;
+
+        spin_lock_irqsave(&dev->lock, flags);
+
+        while ((frame = dev->read_queue)) {
+                dev->read_queue = frame->next;
+                spin_unlock_irqrestore(&dev->lock, flags);
+
+                SET_MSG_CPU(msg, 0);
+                SET_MSG_PROC(msg, 0);
+                SET_MSG_CMD(msg, frame->skb->data[2]);
+                SET_MSG_SCMD(msg, frame->skb->data[3]);
+
+                frame->refnum = *((ushort *) frame->skb->data + 4);
+                frame->msg = *((ulong *) & msg);
+
+                skb_pull(frame->skb, 6);
+
+                pcbit_l3_receive(dev, frame->msg, frame->skb, frame->hdr_len,
+                                 frame->refnum);
+
+                kfree(frame);
+
+                spin_lock_irqsave(&dev->lock, flags);
+        }
+
+        spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+/*
+ * Reads BANK 2 & Reassembles
+ */
+
+static void
+pcbit_receive(struct pcbit_dev *dev)
+{
+        unsigned short tt;
+        u_char cpu,
+         proc;
+        struct frame_buf *frame = NULL;
+        unsigned long flags;
+        u_char type1;
+
+        if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING)
+                return;
+
+        tt = pcbit_readw(dev);
+
+        if ((tt & 0x7fffU) > 511) {
+                printk(KERN_INFO "pcbit: invalid frame length -> TT=%04x\n",
+                       tt);
+                pcbit_l2_error(dev);
+                return;
+        }
+        if (!(tt & 0x8000U)) {  /* Type 0 */
+                type1 = 0;
+
+                if (dev->read_frame) {
+                        printk(KERN_DEBUG "pcbit_receive: Type 0 frame and read_frame != NULL\n");
+                        /* discard previous queued frame */
+                        if (dev->read_frame->skb)
+                                kfree_skb(dev->read_frame->skb);
+                        kfree(dev->read_frame);
+                        dev->read_frame = NULL;
+                }
+                frame = kmalloc(sizeof(struct frame_buf), GFP_ATOMIC);
+
+                if (frame == NULL) {
+                        printk(KERN_WARNING "kmalloc failed\n");
+                        return;
+                }
+                memset(frame, 0, sizeof(struct frame_buf));
+
+                cpu = pcbit_readb(dev);
+                proc = pcbit_readb(dev);
+
+
+                if (cpu != 0x06 && cpu != 0x02) {
+                        printk(KERN_DEBUG "pcbit: invalid cpu value\n");
+                        kfree(frame);
+                        pcbit_l2_error(dev);
+                        return;
+                }
+                /*
+                 * we discard cpu & proc on receiving
+                 * but we read it to update the pointer
+                 */
+
+                frame->hdr_len = pcbit_readw(dev);
+                frame->dt_len = pcbit_readw(dev);
+
+                /*
+                   * 0 sized packet
+                   * I don't know if they are an error or not...
+                   * But they are very frequent
+                   * Not documented
+                 */
+
+                if (frame->hdr_len == 0) {
+                        kfree(frame);
+#ifdef DEBUG
+                        printk(KERN_DEBUG "0 sized frame\n");
+#endif
+                        pcbit_firmware_bug(dev);
+                        return;
+                }
+                /* sanity check the length values */
+                if (frame->hdr_len > 1024 || frame->dt_len > 2048) {
+#ifdef DEBUG
+                        printk(KERN_DEBUG "length problem: ");
+                        printk(KERN_DEBUG "TH=%04x TD=%04x\n",
+                               frame->hdr_len,
+                               frame->dt_len);
+#endif
+                        pcbit_l2_error(dev);
+                        kfree(frame);
+                        return;
+                }
+                /* minimum frame read */
+
+                frame->skb = dev_alloc_skb(frame->hdr_len + frame->dt_len +
+                                           ((frame->hdr_len + 15) & ~15));
+
+                if (!frame->skb) {
+                        printk(KERN_DEBUG "pcbit_receive: out of memory\n");
+                        kfree(frame);
+                        return;
+                }
+                /* 16 byte alignment for IP */
+                if (frame->dt_len)
+                        skb_reserve(frame->skb, (frame->hdr_len + 15) & ~15);
+
+        } else {
+                /* Type 1 */
+                type1 = 1;
+                tt &= 0x7fffU;
+
+                if (!(frame = dev->read_frame)) {
+                        printk("Type 1 frame and no frame queued\n");
+                        /* usually after an error: toss frame */
+                        dev->readptr += tt;
+                        if (dev->readptr > dev->sh_mem + BANK2 + BANKLEN)
+                                dev->readptr -= BANKLEN;
+                        return;
+
+                }
+        }
+
+        memcpy_frompcbit(dev, skb_put(frame->skb, tt), tt);
+
+        frame->copied += tt;
+        spin_lock_irqsave(&dev->lock, flags);
+        if (frame->copied == frame->hdr_len + frame->dt_len) {
+
+                if (type1) {
+                        dev->read_frame = NULL;
+                }
+                if (dev->read_queue) {
+                        struct frame_buf *ptr;
+                        for (ptr = dev->read_queue; ptr->next; ptr = ptr->next);
+                        ptr->next = frame;
+                } else
+                        dev->read_queue = frame;
+
+        } else {
+                dev->read_frame = frame;
+        }
+        spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+/*
+ *  The board sends 0 sized frames
+ *  They are TDATA_CONFs that get messed up somehow
+ *  gotta send a fake acknowledgment to the upper layer somehow
+ */
+
+static __inline__ void
+pcbit_fake_conf(struct pcbit_dev *dev, struct pcbit_chan *chan)
+{
+        isdn_ctrl ictl;
+
+        if (chan->queued) {
+                chan->queued--;
+
+                ictl.driver = dev->id;
+                ictl.command = ISDN_STAT_BSENT;
+                ictl.arg = chan->id;
+                dev->dev_if->statcallb(&ictl);
+        }
+}
+
+static void
+pcbit_firmware_bug(struct pcbit_dev *dev)
+{
+        struct pcbit_chan *chan;
+
+        chan = dev->b1;
+
+        if (chan->fsm_state == ST_ACTIVE) {
+                pcbit_fake_conf(dev, chan);
+        }
+        chan = dev->b2;
+
+        if (chan->fsm_state == ST_ACTIVE) {
+                pcbit_fake_conf(dev, chan);
+        }
+}
+
+irqreturn_t
+pcbit_irq_handler(int interrupt, void *devptr, struct pt_regs *regs)
+{
+        struct pcbit_dev *dev;
+        u_char info,
+         ack_seq,
+         read_seq;
+
+        dev = (struct pcbit_dev *) devptr;
+
+        if (!dev) {
+                printk(KERN_WARNING "pcbit_irq_handler: wrong device\n");
+                return IRQ_NONE;
+        }
+        if (dev->interrupt) {
+                printk(KERN_DEBUG "pcbit: reentering interrupt hander\n");
+                return IRQ_HANDLED;
+        }
+        dev->interrupt = 1;
+
+        info = readb(dev->sh_mem + BANK3);
+
+        if (dev->l2_state == L2_STARTING || dev->l2_state == L2_ERROR) {
+                pcbit_l2_active_conf(dev, info);
+                dev->interrupt = 0;
+                return IRQ_HANDLED;
+        }
+        if (info & 0x40U) {     /* E bit set */
+#ifdef DEBUG
+                printk(KERN_DEBUG "pcbit_irq_handler: E bit on\n");
+#endif
+                pcbit_l2_error(dev);
+                dev->interrupt = 0;
+                return IRQ_HANDLED;
+        }
+        if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) {
+                dev->interrupt = 0;
+                return IRQ_HANDLED;
+        }
+        ack_seq = (info >> 3) & 0x07U;
+        read_seq = (info & 0x07U);
+
+        dev->interrupt = 0;
+
+        if (read_seq != dev->rcv_seq) {
+                while (read_seq != dev->rcv_seq) {
+                        pcbit_receive(dev);
+                        dev->rcv_seq = (dev->rcv_seq + 1) % 8;
+                }
+                pcbit_sched_delivery(dev);
+        }
+        if (ack_seq != dev->unack_seq) {
+                pcbit_recv_ack(dev, ack_seq);
+        }
+        info = dev->rcv_seq << 3;
+        info |= dev->send_seq;
+
+        writeb(info, dev->sh_mem + BANK4);
+        return IRQ_HANDLED;
+}
+
+
+static void
+pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info)
+{
+        u_char state;
+
+        state = dev->l2_state;
+
+#ifdef DEBUG
+        printk(KERN_DEBUG "layer2_active_confirm\n");
+#endif
+
+
+        if (info & 0x80U) {
+                dev->rcv_seq = info & 0x07U;
+                dev->l2_state = L2_RUNNING;
+        } else
+                dev->l2_state = L2_DOWN;
+
+        if (state == L2_STARTING)
+                wake_up_interruptible(&dev->set_running_wq);
+
+        if (state == L2_ERROR && dev->l2_state == L2_RUNNING) {
+                pcbit_transmit(dev);
+        }
+}
+
+static void
+pcbit_l2_err_recover(unsigned long data)
+{
+
+        struct pcbit_dev *dev;
+        struct frame_buf *frame;
+
+        dev = (struct pcbit_dev *) data;
+
+        del_timer(&dev->error_recover_timer);
+        if (dev->w_busy || dev->r_busy) {
+                init_timer(&dev->error_recover_timer);
+                dev->error_recover_timer.expires = jiffies + ERRTIME;
+                add_timer(&dev->error_recover_timer);
+                return;
+        }
+        dev->w_busy = dev->r_busy = 1;
+
+        if (dev->read_frame) {
+                if (dev->read_frame->skb)
+                        kfree_skb(dev->read_frame->skb);
+                kfree(dev->read_frame);
+                dev->read_frame = NULL;
+        }
+        if (dev->write_queue) {
+                frame = dev->write_queue;
+#ifdef FREE_ON_ERROR
+                dev->write_queue = dev->write_queue->next;
+
+                if (frame->skb) {
+                        dev_kfree_skb(frame->skb);
+                }
+                kfree(frame);
+#else
+                frame->copied = 0;
+#endif
+        }
+        dev->rcv_seq = dev->send_seq = dev->unack_seq = 0;
+        dev->free = 511;
+        dev->l2_state = L2_ERROR;
+
+        /* this is an hack... */
+        pcbit_firmware_bug(dev);
+
+        dev->writeptr = dev->sh_mem;
+        dev->readptr = dev->sh_mem + BANK2;
+
+        writeb((0x80U | ((dev->rcv_seq & 0x07) << 3) | (dev->send_seq & 0x07)),
+               dev->sh_mem + BANK4);
+        dev->w_busy = dev->r_busy = 0;
+
+}
+
+static void
+pcbit_l2_error(struct pcbit_dev *dev)
+{
+        if (dev->l2_state == L2_RUNNING) {
+
+                printk(KERN_INFO "pcbit: layer 2 error\n");
+
+#ifdef DEBUG
+                log_state(dev);
+#endif
+
+                dev->l2_state = L2_DOWN;
+
+                init_timer(&dev->error_recover_timer);
+                dev->error_recover_timer.function = &pcbit_l2_err_recover;
+                dev->error_recover_timer.data = (ulong) dev;
+                dev->error_recover_timer.expires = jiffies + ERRTIME;
+                add_timer(&dev->error_recover_timer);
+        }
+}
+
+/*
+ * Description:
+ * if board acks frames
+ *   update dev->free
+ *   call pcbit_transmit to write possible queued frames
+ */
+
+static void
+pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack)
+{
+        int i,
+         count;
+        int unacked;
+
+        unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07;
+
+        /* dev->unack_seq < ack <= dev->send_seq; */
+
+        if (unacked) {
+
+                if (dev->send_seq > dev->unack_seq) {
+                        if (ack <= dev->unack_seq || ack > dev->send_seq) {
+                                printk(KERN_DEBUG
+                                     "layer 2 ack unacceptable - dev %d",
+                                       dev->id);
+
+                                pcbit_l2_error(dev);
+                        } else if (ack > dev->send_seq && ack <= dev->unack_seq) {
+                                printk(KERN_DEBUG
+                                     "layer 2 ack unacceptable - dev %d",
+                                       dev->id);
+                                pcbit_l2_error(dev);
+                        }
+                }
+                /* ack is acceptable */
+
+
+                i = dev->unack_seq;
+
+                do {
+                        dev->unack_seq = i = (i + 1) % 8;
+                        dev->free += dev->fsize[i];
+                } while (i != ack);
+
+                count = 0;
+                while (count < 7 && dev->write_queue) {
+                        u8 lsend_seq = dev->send_seq;
+
+                        pcbit_transmit(dev);
+
+                        if (dev->send_seq == lsend_seq)
+                                break;
+                        count++;
+                }
+        } else
+                printk(KERN_DEBUG "recv_ack: unacked = 0\n");
+}