[BNX2]: Move rx indexes into bnx2_napi struct.
[linux-2.6.git] / drivers / net / ppp_generic.c
index 3b377f6..4f69037 100644 (file)
  * ==FILEVERSION 20041108==
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/kmod.h>
 #include <linux/init.h>
 #include <linux/list.h>
-#include <linux/devfs_fs_kernel.h>
 #include <linux/netdevice.h>
 #include <linux/poll.h>
 #include <linux/ppp_defs.h>
 #include <linux/ip.h>
 #include <linux/tcp.h>
 #include <linux/spinlock.h>
-#include <linux/smp_lock.h>
 #include <linux/rwsem.h>
 #include <linux/stddef.h>
 #include <linux/device.h>
+#include <linux/mutex.h>
 #include <net/slhc_vj.h>
 #include <asm/atomic.h>
 
@@ -84,13 +82,11 @@ struct ppp_file {
        int             dead;           /* unit/channel has been shut down */
 };
 
-#define PF_TO_X(pf, X)         ((X *)((char *)(pf) - offsetof(X, file)))
+#define PF_TO_X(pf, X)         container_of(pf, X, file)
 
 #define PF_TO_PPP(pf)          PF_TO_X(pf, struct ppp)
 #define PF_TO_CHANNEL(pf)      PF_TO_X(pf, struct channel)
 
-#define ROUNDUP(n, x)          (((n) + (x) - 1) / (x))
-
 /*
  * Data structure describing one ppp unit.
  * A ppp unit corresponds to a ppp network interface device
@@ -137,13 +133,14 @@ struct ppp {
 
 /*
  * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC,
- * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP.
+ * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP,
+ * SC_MUST_COMP
  * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR.
  * Bits in xstate: SC_COMP_RUN
  */
 #define SC_FLAG_BITS   (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
                         |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \
-                        |SC_COMP_TCP|SC_REJ_COMP_TCP)
+                        |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP)
 
 /*
  * Private data structure for each channel.
@@ -192,16 +189,16 @@ struct cardmap {
        void *ptr[CARDMAP_WIDTH];
 };
 static void *cardmap_get(struct cardmap *map, unsigned int nr);
-static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
+static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
 static unsigned int cardmap_find_first_free(struct cardmap *map);
 static void cardmap_destroy(struct cardmap **map);
 
 /*
- * all_ppp_sem protects the all_ppp_units mapping.
+ * all_ppp_mutex protects the all_ppp_units mapping.
  * It also ensures that finding a ppp unit in the all_ppp_units map
  * and updating its file.refcnt field is atomic.
  */
-static DECLARE_MUTEX(all_ppp_sem);
+static DEFINE_MUTEX(all_ppp_mutex);
 static struct cardmap *all_ppp_units;
 static atomic_t ppp_unit_count = ATOMIC_INIT(0);
 
@@ -273,7 +270,7 @@ static int ppp_connect_channel(struct channel *pch, int unit);
 static int ppp_disconnect_channel(struct channel *pch);
 static void ppp_destroy_channel(struct channel *pch);
 
-static struct class_simple *ppp_class;
+static struct class *ppp_class;
 
 /* Translates a PPP protocol number to a NP index (NP == network protocol) */
 static inline int proto_to_npindex(int proto)
@@ -304,7 +301,7 @@ static const int npindex_to_proto[NUM_NP] = {
        PPP_MPLS_UC,
        PPP_MPLS_MC,
 };
-       
+
 /* Translates an ethertype into an NP index */
 static inline int ethertype_to_npindex(int ethertype)
 {
@@ -370,7 +367,7 @@ static int ppp_release(struct inode *inode, struct file *file)
        struct ppp_file *pf = file->private_data;
        struct ppp *ppp;
 
-       if (pf != 0) {
+       if (pf) {
                file->private_data = NULL;
                if (pf->kind == INTERFACE) {
                        ppp = PF_TO_PPP(pf);
@@ -401,7 +398,7 @@ static ssize_t ppp_read(struct file *file, char __user *buf,
 
        ret = count;
 
-       if (pf == 0)
+       if (!pf)
                return -ENXIO;
        add_wait_queue(&pf->rwait, &wait);
        for (;;) {
@@ -434,7 +431,7 @@ static ssize_t ppp_read(struct file *file, char __user *buf,
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&pf->rwait, &wait);
 
-       if (skb == 0)
+       if (!skb)
                goto out;
 
        ret = -EOVERFLOW;
@@ -458,11 +455,11 @@ static ssize_t ppp_write(struct file *file, const char __user *buf,
        struct sk_buff *skb;
        ssize_t ret;
 
-       if (pf == 0)
+       if (!pf)
                return -ENXIO;
        ret = -ENOMEM;
        skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL);
-       if (skb == 0)
+       if (!skb)
                goto out;
        skb_reserve(skb, pf->hdrlen);
        ret = -EFAULT;
@@ -494,11 +491,11 @@ static unsigned int ppp_poll(struct file *file, poll_table *wait)
        struct ppp_file *pf = file->private_data;
        unsigned int mask;
 
-       if (pf == 0)
+       if (!pf)
                return 0;
        poll_wait(file, &pf->rwait, wait);
        mask = POLLOUT | POLLWRNORM;
-       if (skb_peek(&pf->rq) != 0)
+       if (skb_peek(&pf->rq))
                mask |= POLLIN | POLLRDNORM;
        if (pf->dead)
                mask |= POLLHUP;
@@ -523,9 +520,6 @@ static int get_filter(void __user *arg, struct sock_filter **p)
        if (copy_from_user(&uprog, arg, sizeof(uprog)))
                return -EFAULT;
 
-       if (uprog.len > BPF_MAXINSNS)
-               return -EINVAL;
-
        if (!uprog.len) {
                *p = NULL;
                return 0;
@@ -565,7 +559,7 @@ static int ppp_ioctl(struct inode *inode, struct file *file,
        void __user *argp = (void __user *)arg;
        int __user *p = argp;
 
-       if (pf == 0)
+       if (!pf)
                return ppp_unattached_ioctl(pf, file, cmd, arg);
 
        if (cmd == PPPIOCDETACH) {
@@ -695,13 +689,13 @@ static int ppp_ioctl(struct inode *inode, struct file *file,
                        val &= 0xffff;
                }
                vj = slhc_init(val2+1, val+1);
-               if (vj == 0) {
+               if (!vj) {
                        printk(KERN_ERR "PPP: no memory (VJ compressor)\n");
                        err = -ENOMEM;
                        break;
                }
                ppp_lock(ppp);
-               if (ppp->vj != 0)
+               if (ppp->vj)
                        slhc_free(ppp->vj);
                ppp->vj = vj;
                ppp_unlock(ppp);
@@ -792,7 +786,7 @@ static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
                if (get_user(unit, p))
                        break;
                ppp = ppp_create_interface(unit, &err);
-               if (ppp == 0)
+               if (!ppp)
                        break;
                file->private_data = &ppp->file;
                ppp->owner = file;
@@ -806,15 +800,15 @@ static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
                /* Attach to an existing ppp unit */
                if (get_user(unit, p))
                        break;
-               down(&all_ppp_sem);
+               mutex_lock(&all_ppp_mutex);
                err = -ENXIO;
                ppp = ppp_find_unit(unit);
-               if (ppp != 0) {
+               if (ppp) {
                        atomic_inc(&ppp->file.refcnt);
                        file->private_data = &ppp->file;
                        err = 0;
                }
-               up(&all_ppp_sem);
+               mutex_unlock(&all_ppp_mutex);
                break;
 
        case PPPIOCATTCHAN:
@@ -823,7 +817,7 @@ static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
                spin_lock_bh(&all_channels_lock);
                err = -ENXIO;
                chan = ppp_find_channel(unit);
-               if (chan != 0) {
+               if (chan) {
                        atomic_inc(&chan->file.refcnt);
                        file->private_data = &chan->file;
                        err = 0;
@@ -837,7 +831,7 @@ static int ppp_unattached_ioctl(struct ppp_file *pf, struct file *file,
        return err;
 }
 
-static struct file_operations ppp_device_fops = {
+static const struct file_operations ppp_device_fops = {
        .owner          = THIS_MODULE,
        .read           = ppp_read,
        .write          = ppp_write,
@@ -858,16 +852,12 @@ static int __init ppp_init(void)
        printk(KERN_INFO "PPP generic driver version " PPP_VERSION "\n");
        err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops);
        if (!err) {
-               ppp_class = class_simple_create(THIS_MODULE, "ppp");
+               ppp_class = class_create(THIS_MODULE, "ppp");
                if (IS_ERR(ppp_class)) {
                        err = PTR_ERR(ppp_class);
                        goto out_chrdev;
                }
-               class_simple_device_add(ppp_class, MKDEV(PPP_MAJOR, 0), NULL, "ppp");
-               err = devfs_mk_cdev(MKDEV(PPP_MAJOR, 0),
-                               S_IFCHR|S_IRUSR|S_IWUSR, "ppp");
-               if (err)
-                       goto out_class;
+               device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), "ppp");
        }
 
 out:
@@ -875,9 +865,6 @@ out:
                printk(KERN_ERR "failed to register PPP device (%d)\n", err);
        return err;
 
-out_class:
-       class_simple_device_remove(MKDEV(PPP_MAJOR,0));
-       class_simple_destroy(ppp_class);
 out_chrdev:
        unregister_chrdev(PPP_MAJOR, "ppp");
        goto out;
@@ -912,17 +899,9 @@ ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        /* Put the 2-byte PPP protocol number on the front,
           making sure there is room for the address and control fields. */
-       if (skb_headroom(skb) < PPP_HDRLEN) {
-               struct sk_buff *ns;
-
-               ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC);
-               if (ns == 0)
-                       goto outf;
-               skb_reserve(ns, dev->hard_header_len);
-               skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len);
-               kfree_skb(skb);
-               skb = ns;
-       }
+       if (skb_cow_head(skb, PPP_HDRLEN))
+               goto outf;
+
        pp = skb_push(skb, 2);
        proto = npindex_to_proto[npi];
        pp[0] = proto >> 8;
@@ -967,9 +946,9 @@ ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 
        case SIOCGPPPCSTATS:
                memset(&cstats, 0, sizeof(cstats));
-               if (ppp->xc_state != 0)
+               if (ppp->xc_state)
                        ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c);
-               if (ppp->rc_state != 0)
+               if (ppp->rc_state)
                        ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d);
                if (copy_to_user(addr, &cstats, sizeof(cstats)))
                        break;
@@ -1014,19 +993,69 @@ ppp_xmit_process(struct ppp *ppp)
        struct sk_buff *skb;
 
        ppp_xmit_lock(ppp);
-       if (ppp->dev != 0) {
+       if (ppp->dev) {
                ppp_push(ppp);
-               while (ppp->xmit_pending == 0
-                      && (skb = skb_dequeue(&ppp->file.xq)) != 0)
+               while (!ppp->xmit_pending
+                      && (skb = skb_dequeue(&ppp->file.xq)))
                        ppp_send_frame(ppp, skb);
                /* If there's no work left to do, tell the core net
                   code that we can accept some more. */
-               if (ppp->xmit_pending == 0 && skb_peek(&ppp->file.xq) == 0)
+               if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq))
                        netif_wake_queue(ppp->dev);
        }
        ppp_xmit_unlock(ppp);
 }
 
+static inline struct sk_buff *
+pad_compress_skb(struct ppp *ppp, struct sk_buff *skb)
+{
+       struct sk_buff *new_skb;
+       int len;
+       int new_skb_size = ppp->dev->mtu +
+               ppp->xcomp->comp_extra + ppp->dev->hard_header_len;
+       int compressor_skb_size = ppp->dev->mtu +
+               ppp->xcomp->comp_extra + PPP_HDRLEN;
+       new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
+       if (!new_skb) {
+               if (net_ratelimit())
+                       printk(KERN_ERR "PPP: no memory (comp pkt)\n");
+               return NULL;
+       }
+       if (ppp->dev->hard_header_len > PPP_HDRLEN)
+               skb_reserve(new_skb,
+                           ppp->dev->hard_header_len - PPP_HDRLEN);
+
+       /* compressor still expects A/C bytes in hdr */
+       len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
+                                  new_skb->data, skb->len + 2,
+                                  compressor_skb_size);
+       if (len > 0 && (ppp->flags & SC_CCP_UP)) {
+               kfree_skb(skb);
+               skb = new_skb;
+               skb_put(skb, len);
+               skb_pull(skb, 2);       /* pull off A/C bytes */
+       } else if (len == 0) {
+               /* didn't compress, or CCP not up yet */
+               kfree_skb(new_skb);
+               new_skb = skb;
+       } else {
+               /*
+                * (len < 0)
+                * MPPE requires that we do not send unencrypted
+                * frames.  The compressor will return -1 if we
+                * should drop the frame.  We cannot simply test
+                * the compress_proto because MPPE and MPPC share
+                * the same number.
+                */
+               if (net_ratelimit())
+                       printk(KERN_ERR "ppp: compressor dropped pkt\n");
+               kfree_skb(skb);
+               kfree_skb(new_skb);
+               new_skb = NULL;
+       }
+       return new_skb;
+}
+
 /*
  * Compress and send a frame.
  * The caller should have locked the xmit path,
@@ -1071,12 +1100,12 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
 
        switch (proto) {
        case PPP_IP:
-               if (ppp->vj == 0 || (ppp->flags & SC_COMP_TCP) == 0)
+               if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0)
                        break;
                /* try to do VJ TCP header compression */
                new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2,
                                    GFP_ATOMIC);
-               if (new_skb == 0) {
+               if (!new_skb) {
                        printk(KERN_ERR "PPP: no memory (VJ comp pkt)\n");
                        goto drop;
                }
@@ -1111,31 +1140,16 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
        }
 
        /* try to do packet compression */
-       if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
+       if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state
            && proto != PPP_LCP && proto != PPP_CCP) {
-               new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
-                                   GFP_ATOMIC);
-               if (new_skb == 0) {
-                       printk(KERN_ERR "PPP: no memory (comp pkt)\n");
+               if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) {
+                       if (net_ratelimit())
+                               printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n");
                        goto drop;
                }
-               if (ppp->dev->hard_header_len > PPP_HDRLEN)
-                       skb_reserve(new_skb,
-                                   ppp->dev->hard_header_len - PPP_HDRLEN);
-
-               /* compressor still expects A/C bytes in hdr */
-               len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
-                                          new_skb->data, skb->len + 2,
-                                          ppp->dev->mtu + PPP_HDRLEN);
-               if (len > 0 && (ppp->flags & SC_CCP_UP)) {
-                       kfree_skb(skb);
-                       skb = new_skb;
-                       skb_put(skb, len);
-                       skb_pull(skb, 2);       /* pull off A/C bytes */
-               } else {
-                       /* didn't compress, or CCP not up yet */
-                       kfree_skb(new_skb);
-               }
+               skb = pad_compress_skb(ppp, skb);
+               if (!skb)
+                       goto drop;
        }
 
        /*
@@ -1155,7 +1169,8 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb)
        return;
 
  drop:
-       kfree_skb(skb);
+       if (skb)
+               kfree_skb(skb);
        ++ppp->stats.tx_errors;
 }
 
@@ -1170,7 +1185,7 @@ ppp_push(struct ppp *ppp)
        struct channel *pch;
        struct sk_buff *skb = ppp->xmit_pending;
 
-       if (skb == 0)
+       if (!skb)
                return;
 
        list = &ppp->channels;
@@ -1217,36 +1232,41 @@ ppp_push(struct ppp *ppp)
  */
 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
 {
-       int nch, len, fragsize;
+       int len, fragsize;
        int i, bits, hdrlen, mtu;
-       int flen, fnb;
+       int flen;
+       int navail, nfree;
+       int nbigger;
        unsigned char *p, *q;
        struct list_head *list;
        struct channel *pch;
        struct sk_buff *frag;
        struct ppp_channel *chan;
 
-       nch = 0;
+       nfree = 0;      /* # channels which have no packet already queued */
+       navail = 0;     /* total # of usable channels (not deregistered) */
        hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
-       list = &ppp->channels;
-       while ((list = list->next) != &ppp->channels) {
-               pch = list_entry(list, struct channel, clist);
-               nch += pch->avail = (skb_queue_len(&pch->file.xq) == 0);
-               /*
-                * If a channel hasn't had a fragment yet, it has to get
-                * one before we send any fragments on later channels.
-                * If it can't take a fragment now, don't give any
-                * to subsequent channels.
-                */
-               if (!pch->had_frag && !pch->avail) {
-                       while ((list = list->next) != &ppp->channels) {
-                               pch = list_entry(list, struct channel, clist);
-                               pch->avail = 0;
+       i = 0;
+       list_for_each_entry(pch, &ppp->channels, clist) {
+               navail += pch->avail = (pch->chan != NULL);
+               if (pch->avail) {
+                       if (skb_queue_empty(&pch->file.xq) ||
+                           !pch->had_frag) {
+                               pch->avail = 2;
+                               ++nfree;
                        }
-                       break;
+                       if (!pch->had_frag && i < ppp->nxchan)
+                               ppp->nxchan = i;
                }
+               ++i;
        }
-       if (nch == 0)
+
+       /*
+        * Don't start sending this packet unless at least half of
+        * the channels are free.  This gives much better TCP
+        * performance if we have a lot of channels.
+        */
+       if (nfree == 0 || nfree < navail / 2)
                return 0;       /* can't take now, leave it in xmit_pending */
 
        /* Do protocol field compression (XXX this should be optional) */
@@ -1257,17 +1277,23 @@ static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
                --len;
        }
 
-       /* decide on fragment size */
+       /*
+        * Decide on fragment size.
+        * We create a fragment for each free channel regardless of
+        * how small they are (i.e. even 0 length) in order to minimize
+        * the time that it will take to detect when a channel drops
+        * a fragment.
+        */
        fragsize = len;
-       if (nch > 1) {
-               int maxch = ROUNDUP(len, MIN_FRAG_SIZE);
-               if (nch > maxch)
-                       nch = maxch;
-               fragsize = ROUNDUP(fragsize, nch);
-       }
+       if (nfree > 1)
+               fragsize = DIV_ROUND_UP(fragsize, nfree);
+       /* nbigger channels get fragsize bytes, the rest get fragsize-1,
+          except if nbigger==0, then they all get fragsize. */
+       nbigger = len % nfree;
 
        /* skip to the channel after the one we last used
           and start at that one */
+       list = &ppp->channels;
        for (i = 0; i < ppp->nxchan; ++i) {
                list = list->next;
                if (list == &ppp->channels) {
@@ -1278,7 +1304,7 @@ static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
 
        /* create a fragment for each channel */
        bits = B;
-       do {
+       while (nfree > 0 || len > 0) {
                list = list->next;
                if (list == &ppp->channels) {
                        i = 0;
@@ -1289,61 +1315,92 @@ static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb)
                if (!pch->avail)
                        continue;
 
+               /*
+                * Skip this channel if it has a fragment pending already and
+                * we haven't given a fragment to all of the free channels.
+                */
+               if (pch->avail == 1) {
+                       if (nfree > 0)
+                               continue;
+               } else {
+                       --nfree;
+                       pch->avail = 1;
+               }
+
                /* check the channel's mtu and whether it is still attached. */
                spin_lock_bh(&pch->downl);
-               if (pch->chan == 0 || (mtu = pch->chan->mtu) < hdrlen) {
-                       /* can't use this channel */
+               if (pch->chan == NULL) {
+                       /* can't use this channel, it's being deregistered */
                        spin_unlock_bh(&pch->downl);
                        pch->avail = 0;
-                       if (--nch == 0)
+                       if (--navail == 0)
                                break;
                        continue;
                }
 
                /*
-                * We have to create multiple fragments for this channel
-                * if fragsize is greater than the channel's mtu.
+                * Create a fragment for this channel of
+                * min(max(mtu+2-hdrlen, 4), fragsize, len) bytes.
+                * If mtu+2-hdrlen < 4, that is a ridiculously small
+                * MTU, so we use mtu = 2 + hdrlen.
                 */
                if (fragsize > len)
                        fragsize = len;
-               for (flen = fragsize; flen > 0; flen -= fnb) {
-                       fnb = flen;
-                       if (fnb > mtu + 2 - hdrlen)
-                               fnb = mtu + 2 - hdrlen;
-                       if (fnb >= len)
-                               bits |= E;
-                       frag = alloc_skb(fnb + hdrlen, GFP_ATOMIC);
-                       if (frag == 0)
-                               goto noskb;
-                       q = skb_put(frag, fnb + hdrlen);
-                       /* make the MP header */
-                       q[0] = PPP_MP >> 8;
-                       q[1] = PPP_MP;
-                       if (ppp->flags & SC_MP_XSHORTSEQ) {
-                               q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
-                               q[3] = ppp->nxseq;
-                       } else {
-                               q[2] = bits;
-                               q[3] = ppp->nxseq >> 16;
-                               q[4] = ppp->nxseq >> 8;
-                               q[5] = ppp->nxseq;
-                       }
-
-                       /* copy the data in */
-                       memcpy(q + hdrlen, p, fnb);
-
-                       /* try to send it down the channel */
-                       chan = pch->chan;
-                       if (!chan->ops->start_xmit(chan, frag))
-                               skb_queue_tail(&pch->file.xq, frag);
-                       pch->had_frag = 1;
-                       p += fnb;
-                       len -= fnb;
-                       ++ppp->nxseq;
-                       bits = 0;
+               flen = fragsize;
+               mtu = pch->chan->mtu + 2 - hdrlen;
+               if (mtu < 4)
+                       mtu = 4;
+               if (flen > mtu)
+                       flen = mtu;
+               if (flen == len && nfree == 0)
+                       bits |= E;
+               frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC);
+               if (!frag)
+                       goto noskb;
+               q = skb_put(frag, flen + hdrlen);
+
+               /* make the MP header */
+               q[0] = PPP_MP >> 8;
+               q[1] = PPP_MP;
+               if (ppp->flags & SC_MP_XSHORTSEQ) {
+                       q[2] = bits + ((ppp->nxseq >> 8) & 0xf);
+                       q[3] = ppp->nxseq;
+               } else {
+                       q[2] = bits;
+                       q[3] = ppp->nxseq >> 16;
+                       q[4] = ppp->nxseq >> 8;
+                       q[5] = ppp->nxseq;
                }
+
+               /*
+                * Copy the data in.
+                * Unfortunately there is a bug in older versions of
+                * the Linux PPP multilink reconstruction code where it
+                * drops 0-length fragments.  Therefore we make sure the
+                * fragment has at least one byte of data.  Any bytes
+                * we add in this situation will end up as padding on the
+                * end of the reconstructed packet.
+                */
+               if (flen == 0)
+                       *skb_put(frag, 1) = 0;
+               else
+                       memcpy(q + hdrlen, p, flen);
+
+               /* try to send it down the channel */
+               chan = pch->chan;
+               if (!skb_queue_empty(&pch->file.xq) ||
+                   !chan->ops->start_xmit(chan, frag))
+                       skb_queue_tail(&pch->file.xq, frag);
+               pch->had_frag = 1;
+               p += flen;
+               len -= flen;
+               ++ppp->nxseq;
+               bits = 0;
                spin_unlock_bh(&pch->downl);
-       } while (len > 0);
+
+               if (--nbigger == 0 && fragsize > 0)
+                       --fragsize;
+       }
        ppp->nxchan = i;
 
        return 1;
@@ -1368,8 +1425,8 @@ ppp_channel_push(struct channel *pch)
        struct ppp *ppp;
 
        spin_lock_bh(&pch->downl);
-       if (pch->chan != 0) {
-               while (skb_queue_len(&pch->file.xq) > 0) {
+       if (pch->chan) {
+               while (!skb_queue_empty(&pch->file.xq)) {
                        skb = skb_dequeue(&pch->file.xq);
                        if (!pch->chan->ops->start_xmit(pch->chan, skb)) {
                                /* put the packet back and try again later */
@@ -1383,10 +1440,10 @@ ppp_channel_push(struct channel *pch)
        }
        spin_unlock_bh(&pch->downl);
        /* see if there is anything from the attached unit to be sent */
-       if (skb_queue_len(&pch->file.xq) == 0) {
+       if (skb_queue_empty(&pch->file.xq)) {
                read_lock_bh(&pch->upl);
                ppp = pch->ppp;
-               if (ppp != 0)
+               if (ppp)
                        ppp_xmit_process(ppp);
                read_unlock_bh(&pch->upl);
        }
@@ -1405,7 +1462,7 @@ ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
 {
        ppp_recv_lock(ppp);
        /* ppp->dev == 0 means interface is closing down */
-       if (ppp->dev != 0)
+       if (ppp->dev)
                ppp_receive_frame(ppp, skb, pch);
        else
                kfree_skb(skb);
@@ -1418,19 +1475,19 @@ ppp_input(struct ppp_channel *chan, struct sk_buff *skb)
        struct channel *pch = chan->ppp;
        int proto;
 
-       if (pch == 0 || skb->len == 0) {
+       if (!pch || skb->len == 0) {
                kfree_skb(skb);
                return;
        }
-       
+
        proto = PPP_PROTO(skb);
        read_lock_bh(&pch->upl);
-       if (pch->ppp == 0 || proto >= 0xc000 || proto == PPP_CCPFRAG) {
+       if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) {
                /* put it on the channel queue */
                skb_queue_tail(&pch->file.rq, skb);
                /* drop old frames if queue too long */
                while (pch->file.rq.qlen > PPP_MAX_RQLEN
-                      && (skb = skb_dequeue(&pch->file.rq)) != 0)
+                      && (skb = skb_dequeue(&pch->file.rq)))
                        kfree_skb(skb);
                wake_up_interruptible(&pch->file.rwait);
        } else {
@@ -1446,13 +1503,13 @@ ppp_input_error(struct ppp_channel *chan, int code)
        struct channel *pch = chan->ppp;
        struct sk_buff *skb;
 
-       if (pch == 0)
+       if (!pch)
                return;
 
        read_lock_bh(&pch->upl);
-       if (pch->ppp != 0) {
+       if (pch->ppp) {
                skb = alloc_skb(0, GFP_ATOMIC);
-               if (skb != 0) {
+               if (skb) {
                        skb->len = 0;           /* probably unnecessary */
                        skb->cb[0] = code;
                        ppp_do_recv(pch->ppp, skb, pch);
@@ -1468,7 +1525,7 @@ ppp_input_error(struct ppp_channel *chan, int code)
 static void
 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
 {
-       if (skb->len >= 2) {
+       if (pskb_may_pull(skb, 2)) {
 #ifdef CONFIG_PPP_MULTILINK
                /* XXX do channel-level decompression here */
                if (PPP_PROTO(skb) == PPP_MP)
@@ -1491,7 +1548,7 @@ static void
 ppp_receive_error(struct ppp *ppp)
 {
        ++ppp->stats.rx_errors;
-       if (ppp->vj != 0)
+       if (ppp->vj)
                slhc_toss(ppp->vj);
 }
 
@@ -1506,21 +1563,24 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
         * Note that some decompressors need to see uncompressed frames
         * that come in as well as compressed frames.
         */
-       if (ppp->rc_state != 0 && (ppp->rstate & SC_DECOMP_RUN)
+       if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)
            && (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
                skb = ppp_decompress_frame(ppp, skb);
 
+       if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
+               goto err;
+
        proto = PPP_PROTO(skb);
        switch (proto) {
        case PPP_VJC_COMP:
                /* decompress VJ compressed packets */
-               if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
+               if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
                        goto err;
 
-               if (skb_tailroom(skb) < 124) {
+               if (skb_tailroom(skb) < 124 || skb_cloned(skb)) {
                        /* copy to a new sk_buff with more tailroom */
                        ns = dev_alloc_skb(skb->len + 128);
-                       if (ns == 0) {
+                       if (!ns) {
                                printk(KERN_ERR"PPP: no memory (VJ decomp)\n");
                                goto err;
                        }
@@ -1529,8 +1589,8 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
                        kfree_skb(skb);
                        skb = ns;
                }
-               else if (!pskb_may_pull(skb, skb->len))
-                       goto err;
+               else
+                       skb->ip_summed = CHECKSUM_NONE;
 
                len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
                if (len <= 0) {
@@ -1546,13 +1606,13 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
                break;
 
        case PPP_VJC_UNCOMP:
-               if (ppp->vj == 0 || (ppp->flags & SC_REJ_COMP_TCP))
+               if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP))
                        goto err;
-               
+
                /* Until we fix the decompressor need to make sure
                 * data portion is linear.
                 */
-               if (!pskb_may_pull(skb, skb->len)) 
+               if (!pskb_may_pull(skb, skb->len))
                        goto err;
 
                if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) {
@@ -1576,7 +1636,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
                skb_queue_tail(&ppp->file.rq, skb);
                /* limit queue length by dropping old frames */
                while (ppp->file.rq.qlen > PPP_MAX_RQLEN
-                      && (skb = skb_dequeue(&ppp->file.rq)) != 0)
+                      && (skb = skb_dequeue(&ppp->file.rq)))
                        kfree_skb(skb);
                /* wake up any process polling or blocking on read */
                wake_up_interruptible(&ppp->file.rwait);
@@ -1588,33 +1648,39 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
                /* check if the packet passes the pass and active filters */
                /* the filter instructions are constructed assuming
                   a four-byte PPP header on each packet */
-               *skb_push(skb, 2) = 0;
-               if (ppp->pass_filter
-                   && sk_run_filter(skb, ppp->pass_filter,
-                                    ppp->pass_len) == 0) {
-                       if (ppp->debug & 1)
-                               printk(KERN_DEBUG "PPP: inbound frame not passed\n");
-                       kfree_skb(skb);
-                       return;
-               }
-               if (!(ppp->active_filter
-                     && sk_run_filter(skb, ppp->active_filter,
-                                      ppp->active_len) == 0))
-                       ppp->last_recv = jiffies;
-               skb_pull(skb, 2);
-#else
-               ppp->last_recv = jiffies;
+               if (ppp->pass_filter || ppp->active_filter) {
+                       if (skb_cloned(skb) &&
+                           pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+                               goto err;
+
+                       *skb_push(skb, 2) = 0;
+                       if (ppp->pass_filter
+                           && sk_run_filter(skb, ppp->pass_filter,
+                                            ppp->pass_len) == 0) {
+                               if (ppp->debug & 1)
+                                       printk(KERN_DEBUG "PPP: inbound frame "
+                                              "not passed\n");
+                               kfree_skb(skb);
+                               return;
+                       }
+                       if (!(ppp->active_filter
+                             && sk_run_filter(skb, ppp->active_filter,
+                                              ppp->active_len) == 0))
+                               ppp->last_recv = jiffies;
+                       __skb_pull(skb, 2);
+               } else
 #endif /* CONFIG_PPP_FILTER */
+                       ppp->last_recv = jiffies;
 
                if ((ppp->dev->flags & IFF_UP) == 0
                    || ppp->npmode[npi] != NPMODE_PASS) {
                        kfree_skb(skb);
                } else {
-                       skb_pull(skb, 2);       /* chop off protocol */
+                       /* chop off protocol */
+                       skb_pull_rcsum(skb, 2);
                        skb->dev = ppp->dev;
                        skb->protocol = htons(npindex_to_ethertype[npi]);
-                       skb->mac.raw = skb->data;
-                       skb->input_dev = ppp->dev;
+                       skb_reset_mac_header(skb);
                        netif_rx(skb);
                        ppp->dev->last_rx = jiffies;
                }
@@ -1640,14 +1706,25 @@ ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
                goto err;
 
        if (proto == PPP_COMP) {
-               ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
-               if (ns == 0) {
+               int obuff_size;
+
+               switch(ppp->rcomp->compress_proto) {
+               case CI_MPPE:
+                       obuff_size = ppp->mru + PPP_HDRLEN + 1;
+                       break;
+               default:
+                       obuff_size = ppp->mru + PPP_HDRLEN;
+                       break;
+               }
+
+               ns = dev_alloc_skb(obuff_size);
+               if (!ns) {
                        printk(KERN_ERR "ppp_decompress_frame: no memory\n");
                        goto err;
                }
                /* the decompressor still expects the A/C bytes in the hdr */
                len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
-                               skb->len + 2, ns->data, ppp->mru + PPP_HDRLEN);
+                               skb->len + 2, ns->data, obuff_size);
                if (len < 0) {
                        /* Pass the compressed frame to pppd as an
                           error indication. */
@@ -1688,7 +1765,7 @@ static void
 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
 {
        u32 mask, seq;
-       struct list_head *l;
+       struct channel *ch;
        int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN;
 
        if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0)
@@ -1742,8 +1819,7 @@ ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
         * The list of channels can't change because we have the receive
         * side of the ppp unit locked.
         */
-       for (l = ppp->channels.next; l != &ppp->channels; l = l->next) {
-               struct channel *ch = list_entry(l, struct channel, clist);
+       list_for_each_entry(ch, &ppp->channels, clist) {
                if (seq_before(ch->lastseq, seq))
                        seq = ch->lastseq;
        }
@@ -1760,7 +1836,7 @@ ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
                ppp->minseq = ppp->mrq.next->sequence;
 
        /* Pull completed packets off the queue and receive them. */
-       while ((skb = ppp_mp_reconstruct(ppp)) != 0)
+       while ((skb = ppp_mp_reconstruct(ppp)))
                ppp_receive_nonmp_frame(ppp, skb);
 
        return;
@@ -1925,10 +2001,9 @@ ppp_register_channel(struct ppp_channel *chan)
 {
        struct channel *pch;
 
-       pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
-       if (pch == 0)
+       pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
+       if (!pch)
                return -ENOMEM;
-       memset(pch, 0, sizeof(struct channel));
        pch->ppp = NULL;
        pch->chan = chan;
        chan->ppp = pch;
@@ -1955,7 +2030,7 @@ int ppp_channel_index(struct ppp_channel *chan)
 {
        struct channel *pch = chan->ppp;
 
-       if (pch != 0)
+       if (pch)
                return pch->file.index;
        return -1;
 }
@@ -1968,9 +2043,9 @@ int ppp_unit_number(struct ppp_channel *chan)
        struct channel *pch = chan->ppp;
        int unit = -1;
 
-       if (pch != 0) {
+       if (pch) {
                read_lock_bh(&pch->upl);
-               if (pch->ppp != 0)
+               if (pch->ppp)
                        unit = pch->ppp->file.index;
                read_unlock_bh(&pch->upl);
        }
@@ -1986,7 +2061,7 @@ ppp_unregister_channel(struct ppp_channel *chan)
 {
        struct channel *pch = chan->ppp;
 
-       if (pch == 0)
+       if (!pch)
                return;         /* should never happen */
        chan->ppp = NULL;
 
@@ -2018,7 +2093,7 @@ ppp_output_wakeup(struct ppp_channel *chan)
 {
        struct channel *pch = chan->ppp;
 
-       if (pch == 0)
+       if (!pch)
                return;
        ppp_channel_push(pch);
 }
@@ -2049,18 +2124,18 @@ ppp_set_compress(struct ppp *ppp, unsigned long arg)
 
        cp = find_compressor(ccp_option[0]);
 #ifdef CONFIG_KMOD
-       if (cp == 0) {
+       if (!cp) {
                request_module("ppp-compress-%d", ccp_option[0]);
                cp = find_compressor(ccp_option[0]);
        }
 #endif /* CONFIG_KMOD */
-       if (cp == 0)
+       if (!cp)
                goto out;
 
        err = -ENOBUFS;
        if (data.transmit) {
                state = cp->comp_alloc(ccp_option, data.length);
-               if (state != 0) {
+               if (state) {
                        ppp_xmit_lock(ppp);
                        ppp->xstate &= ~SC_COMP_RUN;
                        ocomp = ppp->xcomp;
@@ -2068,7 +2143,7 @@ ppp_set_compress(struct ppp *ppp, unsigned long arg)
                        ppp->xcomp = cp;
                        ppp->xc_state = state;
                        ppp_xmit_unlock(ppp);
-                       if (ostate != 0) {
+                       if (ostate) {
                                ocomp->comp_free(ostate);
                                module_put(ocomp->owner);
                        }
@@ -2078,7 +2153,7 @@ ppp_set_compress(struct ppp *ppp, unsigned long arg)
 
        } else {
                state = cp->decomp_alloc(ccp_option, data.length);
-               if (state != 0) {
+               if (state) {
                        ppp_recv_lock(ppp);
                        ppp->rstate &= ~SC_DECOMP_RUN;
                        ocomp = ppp->rcomp;
@@ -2086,7 +2161,7 @@ ppp_set_compress(struct ppp *ppp, unsigned long arg)
                        ppp->rcomp = cp;
                        ppp->rc_state = state;
                        ppp_recv_unlock(ppp);
-                       if (ostate != 0) {
+                       if (ostate) {
                                ocomp->decomp_free(ostate);
                                module_put(ocomp->owner);
                        }
@@ -2116,7 +2191,7 @@ ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
        switch (CCP_CODE(dp)) {
        case CCP_CONFREQ:
 
-               /* A ConfReq starts negotiation of compression 
+               /* A ConfReq starts negotiation of compression
                 * in one direction of transmission,
                 * and hence brings it down...but which way?
                 *
@@ -2126,16 +2201,16 @@ ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
                if(inbound)
                        /* He is proposing what I should send */
                        ppp->xstate &= ~SC_COMP_RUN;
-               else    
+               else
                        /* I am proposing to what he should send */
                        ppp->rstate &= ~SC_DECOMP_RUN;
-               
+
                break;
-               
+
        case CCP_TERMREQ:
        case CCP_TERMACK:
                /*
-                * CCP is going down, both directions of transmission 
+                * CCP is going down, both directions of transmission
                 */
                ppp->rstate &= ~SC_DECOMP_RUN;
                ppp->xstate &= ~SC_COMP_RUN;
@@ -2153,7 +2228,7 @@ ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
                        break;
                if (inbound) {
                        /* we will start receiving compressed packets */
-                       if (ppp->rc_state == 0)
+                       if (!ppp->rc_state)
                                break;
                        if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len,
                                        ppp->file.index, 0, ppp->mru, ppp->debug)) {
@@ -2162,7 +2237,7 @@ ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound)
                        }
                } else {
                        /* we will soon start sending compressed packets */
-                       if (ppp->xc_state == 0)
+                       if (!ppp->xc_state)
                                break;
                        if (ppp->xcomp->comp_init(ppp->xc_state, dp, len,
                                        ppp->file.index, 0, ppp->debug))
@@ -2229,10 +2304,8 @@ static struct compressor_entry *
 find_comp_entry(int proto)
 {
        struct compressor_entry *ce;
-       struct list_head *list = &compressor_list;
 
-       while ((list = list->next) != &compressor_list) {
-               ce = list_entry(list, struct compressor_entry, list);
+       list_for_each_entry(ce, &compressor_list, list) {
                if (ce->comp->compress_proto == proto)
                        return ce;
        }
@@ -2247,11 +2320,11 @@ ppp_register_compressor(struct compressor *cp)
        int ret;
        spin_lock(&compressor_list_lock);
        ret = -EEXIST;
-       if (find_comp_entry(cp->compress_proto) != 0)
+       if (find_comp_entry(cp->compress_proto))
                goto out;
        ret = -ENOMEM;
        ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC);
-       if (ce == 0)
+       if (!ce)
                goto out;
        ret = 0;
        ce->comp = cp;
@@ -2269,7 +2342,7 @@ ppp_unregister_compressor(struct compressor *cp)
 
        spin_lock(&compressor_list_lock);
        ce = find_comp_entry(cp->compress_proto);
-       if (ce != 0 && ce->comp == cp) {
+       if (ce && ce->comp == cp) {
                list_del(&ce->list);
                kfree(ce);
        }
@@ -2285,7 +2358,7 @@ find_compressor(int type)
 
        spin_lock(&compressor_list_lock);
        ce = find_comp_entry(type);
-       if (ce != 0) {
+       if (ce) {
                cp = ce->comp;
                if (!try_module_get(cp->owner))
                        cp = NULL;
@@ -2310,7 +2383,7 @@ ppp_get_stats(struct ppp *ppp, struct ppp_stats *st)
        st->p.ppp_opackets = ppp->stats.tx_packets;
        st->p.ppp_oerrors = ppp->stats.tx_errors;
        st->p.ppp_obytes = ppp->stats.tx_bytes;
-       if (vj == 0)
+       if (!vj)
                return;
        st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed;
        st->vj.vjs_compressed = vj->sls_o_compressed;
@@ -2340,13 +2413,12 @@ ppp_create_interface(int unit, int *retp)
        int ret = -ENOMEM;
        int i;
 
-       ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
+       ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
        if (!ppp)
                goto out;
        dev = alloc_netdev(0, "", ppp_setup);
        if (!dev)
                goto out1;
-       memset(ppp, 0, sizeof(struct ppp));
 
        ppp->mru = PPP_MRU;
        init_ppp_file(&ppp->file, INTERFACE);
@@ -2368,7 +2440,7 @@ ppp_create_interface(int unit, int *retp)
        dev->do_ioctl = ppp_net_ioctl;
 
        ret = -EEXIST;
-       down(&all_ppp_sem);
+       mutex_lock(&all_ppp_mutex);
        if (unit < 0)
                unit = cardmap_find_first_free(all_ppp_units);
        else if (cardmap_get(all_ppp_units, unit) != NULL)
@@ -2386,13 +2458,18 @@ ppp_create_interface(int unit, int *retp)
        }
 
        atomic_inc(&ppp_unit_count);
-       cardmap_set(&all_ppp_units, unit, ppp);
-       up(&all_ppp_sem);
+       ret = cardmap_set(&all_ppp_units, unit, ppp);
+       if (ret != 0)
+               goto out3;
+
+       mutex_unlock(&all_ppp_mutex);
        *retp = 0;
        return ppp;
 
+out3:
+       atomic_dec(&ppp_unit_count);
 out2:
-       up(&all_ppp_sem);
+       mutex_unlock(&all_ppp_mutex);
        free_netdev(dev);
 out1:
        kfree(ppp);
@@ -2422,7 +2499,7 @@ static void ppp_shutdown_interface(struct ppp *ppp)
 {
        struct net_device *dev;
 
-       down(&all_ppp_sem);
+       mutex_lock(&all_ppp_mutex);
        ppp_lock(ppp);
        dev = ppp->dev;
        ppp->dev = NULL;
@@ -2436,7 +2513,7 @@ static void ppp_shutdown_interface(struct ppp *ppp)
        ppp->file.dead = 1;
        ppp->owner = NULL;
        wake_up_interruptible(&ppp->file.rwait);
-       up(&all_ppp_sem);
+       mutex_unlock(&all_ppp_mutex);
 }
 
 /*
@@ -2473,12 +2550,15 @@ static void ppp_destroy_interface(struct ppp *ppp)
        ppp->active_filter = NULL;
 #endif /* CONFIG_PPP_FILTER */
 
+       if (ppp->xmit_pending)
+               kfree_skb(ppp->xmit_pending);
+
        kfree(ppp);
 }
 
 /*
  * Locate an existing ppp unit.
- * The caller should have locked the all_ppp_sem.
+ * The caller should have locked the all_ppp_mutex.
  */
 static struct ppp *
 ppp_find_unit(int unit)
@@ -2498,20 +2578,14 @@ static struct channel *
 ppp_find_channel(int unit)
 {
        struct channel *pch;
-       struct list_head *list;
 
-       list = &new_channels;
-       while ((list = list->next) != &new_channels) {
-               pch = list_entry(list, struct channel, list);
+       list_for_each_entry(pch, &new_channels, list) {
                if (pch->file.index == unit) {
-                       list_del(&pch->list);
-                       list_add(&pch->list, &all_channels);
+                       list_move(&pch->list, &all_channels);
                        return pch;
                }
        }
-       list = &all_channels;
-       while ((list = list->next) != &all_channels) {
-               pch = list_entry(list, struct channel, list);
+       list_for_each_entry(pch, &all_channels, list) {
                if (pch->file.index == unit)
                        return pch;
        }
@@ -2528,13 +2602,13 @@ ppp_connect_channel(struct channel *pch, int unit)
        int ret = -ENXIO;
        int hdrlen;
 
-       down(&all_ppp_sem);
+       mutex_lock(&all_ppp_mutex);
        ppp = ppp_find_unit(unit);
-       if (ppp == 0)
+       if (!ppp)
                goto out;
        write_lock_bh(&pch->upl);
        ret = -EINVAL;
-       if (pch->ppp != 0)
+       if (pch->ppp)
                goto outl;
 
        ppp_lock(ppp);
@@ -2553,7 +2627,7 @@ ppp_connect_channel(struct channel *pch, int unit)
  outl:
        write_unlock_bh(&pch->upl);
  out:
-       up(&all_ppp_sem);
+       mutex_unlock(&all_ppp_mutex);
        return ret;
 }
 
@@ -2570,7 +2644,7 @@ ppp_disconnect_channel(struct channel *pch)
        ppp = pch->ppp;
        pch->ppp = NULL;
        write_unlock_bh(&pch->upl);
-       if (ppp != 0) {
+       if (ppp) {
                /* remove it from the ppp unit's list */
                ppp_lock(ppp);
                list_del(&pch->clist);
@@ -2608,11 +2682,9 @@ static void __exit ppp_cleanup(void)
        if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count))
                printk(KERN_ERR "PPP: removing module but units remain!\n");
        cardmap_destroy(&all_ppp_units);
-       if (unregister_chrdev(PPP_MAJOR, "ppp") != 0)
-               printk(KERN_ERR "PPP: failed to unregister PPP device\n");
-       devfs_remove("ppp");
-       class_simple_device_remove(MKDEV(PPP_MAJOR, 0));
-       class_simple_destroy(ppp_class);
+       unregister_chrdev(PPP_MAJOR, "ppp");
+       device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0));
+       class_destroy(ppp_class);
 }
 
 /*
@@ -2634,7 +2706,7 @@ static void *cardmap_get(struct cardmap *map, unsigned int nr)
        return NULL;
 }
 
-static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
+static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
 {
        struct cardmap *p;
        int i;
@@ -2643,8 +2715,9 @@ static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
        if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
                do {
                        /* need a new top level */
-                       struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
-                       memset(np, 0, sizeof(*np));
+                       struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
+                       if (!np)
+                               goto enomem;
                        np->ptr[0] = p;
                        if (p != NULL) {
                                np->shift = p->shift + CARDMAP_ORDER;
@@ -2658,8 +2731,9 @@ static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
        while (p->shift > 0) {
                i = (nr >> p->shift) & CARDMAP_MASK;
                if (p->ptr[i] == NULL) {
-                       struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
-                       memset(np, 0, sizeof(*np));
+                       struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
+                       if (!np)
+                               goto enomem;
                        np->shift = p->shift - CARDMAP_ORDER;
                        np->parent = p;
                        p->ptr[i] = np;
@@ -2674,6 +2748,9 @@ static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
                set_bit(i, &p->inuse);
        else
                clear_bit(i, &p->inuse);
+       return 0;
+ enomem:
+       return -ENOMEM;
 }
 
 static unsigned int cardmap_find_first_free(struct cardmap *map)