1 files changed, 106 insertions, 0 deletions

diff --git a/net/atm/atm_misc.c b/net/atm/atm_misc.c
new file mode 100644
index 000000000000..b2113c3454ae
--- /dev/null
+++ b/net/atm/atm_misc.c
@@ -0,0 +1,106 @@
+/* net/atm/atm_misc.c - Various functions for use by ATM drivers */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL ICA */
+
+
+#include <linux/module.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/skbuff.h>
+#include <linux/sonet.h>
+#include <linux/bitops.h>
+#include <asm/atomic.h>
+#include <asm/errno.h>
+
+
+int atm_charge(struct atm_vcc *vcc,int truesize)
+{
+        atm_force_charge(vcc,truesize);
+        if (atomic_read(&sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf)
+                return 1;
+        atm_return(vcc,truesize);
+        atomic_inc(&vcc->stats->rx_drop);
+        return 0;
+}
+
+
+struct sk_buff *atm_alloc_charge(struct atm_vcc *vcc,int pdu_size,
+    int gfp_flags)
+{
+        struct sock *sk = sk_atm(vcc);
+        int guess = atm_guess_pdu2truesize(pdu_size);
+
+        atm_force_charge(vcc,guess);
+        if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
+                struct sk_buff *skb = alloc_skb(pdu_size,gfp_flags);
+
+                if (skb) {
+                        atomic_add(skb->truesize-guess,
+                                   &sk->sk_rmem_alloc);
+                        return skb;
+                }
+        }
+        atm_return(vcc,guess);
+        atomic_inc(&vcc->stats->rx_drop);
+        return NULL;
+}
+
+
+/*
+ * atm_pcr_goal returns the positive PCR if it should be rounded up, the
+ * negative PCR if it should be rounded down, and zero if the maximum available
+ * bandwidth should be used.
+ *
+ * The rules are as follows (* = maximum, - = absent (0), x = value "x",
+ * (x+ = x or next value above x, x- = x or next value below):
+ *
+ *      min max pcr     result          min max pcr     result
+ *      -   -   -       * (UBR only)    x   -   -       x+
+ *      -   -   *       *               x   -   *       *
+ *      -   -   z       z-              x   -   z       z-
+ *      -   *   -       *               x   *   -       x+
+ *      -   *   *       *               x   *   *       *
+ *      -   *   z       z-              x   *   z       z-
+ *      -   y   -       y-              x   y   -       x+
+ *      -   y   *       y-              x   y   *       y-
+ *      -   y   z       z-              x   y   z       z-
+ *
+ * All non-error cases can be converted with the following simple set of rules:
+ *
+ *   if pcr == z then z-
+ *   else if min == x && pcr == - then x+
+ *     else if max == y then y-
+ *       else *
+ */
+
+
+int atm_pcr_goal(struct atm_trafprm *tp)
+{
+        if (tp->pcr && tp->pcr != ATM_MAX_PCR) return -tp->pcr;
+        if (tp->min_pcr && !tp->pcr) return tp->min_pcr;
+        if (tp->max_pcr != ATM_MAX_PCR) return -tp->max_pcr;
+        return 0;
+}
+
+
+void sonet_copy_stats(struct k_sonet_stats *from,struct sonet_stats *to)
+{
+#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
+        __SONET_ITEMS
+#undef __HANDLE_ITEM
+}
+
+
+void sonet_subtract_stats(struct k_sonet_stats *from,struct sonet_stats *to)
+{
+#define __HANDLE_ITEM(i) atomic_sub(to->i,&from->i)
+        __SONET_ITEMS
+#undef __HANDLE_ITEM
+}
+
+
+EXPORT_SYMBOL(atm_charge);
+EXPORT_SYMBOL(atm_alloc_charge);
+EXPORT_SYMBOL(atm_pcr_goal);
+EXPORT_SYMBOL(sonet_copy_stats);
+EXPORT_SYMBOL(sonet_subtract_stats);