PERFORCE change 126792 for review

[Kip Macy]

http://perforce.freebsd.org/chv.cgi?CH=126792

Change 126792 by kmacy at kmacy_home:ethng on 2007/09/24 21:51:45

	add stack utility functions for creating LIFO cache

Affected files ...

.. //depot/projects/ethng/src/sys/dev/cxgb/cxgb_osdep.h#9 edit
.. //depot/projects/ethng/src/sys/dev/cxgb/sys/cxgb_support.c#1 add

Differences ...

==== //depot/projects/ethng/src/sys/dev/cxgb/cxgb_osdep.h#9 (text+ko) ====

@@ -100,7 +100,6 @@
 	return (m);
 }
 
-
 static __inline struct mbuf *
 mbuf_ring_peek(struct mbuf_ring *mr)
 {
@@ -118,6 +117,31 @@
 	return (m);
 }
 
+struct buf_stack {
+	caddr_t            *bs_stack;
+	volatile int        bs_head;
+	int                 bs_size;
+};
+
+static __inline int
+buf_push(struct buf_stack *bs, caddr_t buf)
+{
+	if (bs->bs_head + 1 >= bs->bs_size)
+		return (1);
+
+	bs->bs_stack[++(bs->bs_head)] = buf;
+	return (0);
+}
+
+static __inline caddr_t
+buf_pop(struct buf_stack *bs)
+{
+	if (bs->bs_head < 0)
+		return (NULL);
+
+	return (bs->bs_stack[(bs->bs_head)--]);
+}
+
 #define PANIC_IF(exp) do {                  \
 	if (exp)                            \
 		panic("BUG: %s", exp);      \