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-rw-r--r--net/atm/atm_misc.c106
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
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--- /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);
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