[src/trunk]: src/sys/rump/net/lib/libshmif * remove some magic numbers from t...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/7e4f026f4dd0
branches:  trunk
changeset: 757038:7e4f026f4dd0
user:      pooka <pooka%NetBSD.org@localhost>
date:      Wed Aug 11 12:10:39 2010 +0000

description:
* remove some magic numbers from the code
* include bus version number in header just in case we want to examine
  bus traffic at some point in the future

diffstat:

 sys/rump/net/lib/libshmif/if_shmem.c |  27 +++++++++++++++++----------
 1 files changed, 17 insertions(+), 10 deletions(-)

diffs (96 lines):

diff -r 8e3ea0e9f52f -r 7e4f026f4dd0 sys/rump/net/lib/libshmif/if_shmem.c
--- a/sys/rump/net/lib/libshmif/if_shmem.c      Wed Aug 11 12:04:49 2010 +0000
+++ b/sys/rump/net/lib/libshmif/if_shmem.c      Wed Aug 11 12:10:39 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_shmem.c,v 1.14 2010/08/11 10:30:30 pooka Exp $      */
+/*     $NetBSD: if_shmem.c,v 1.15 2010/08/11 12:10:39 pooka Exp $      */
 
 /*
  * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.14 2010/08/11 10:30:30 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.15 2010/08/11 12:10:39 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
@@ -80,11 +80,16 @@
 #define IFMEM_GENERATION       (0x04)
 #define IFMEM_LASTPACKET       (0x08)
 #define IFMEM_WAKEUP           (0x0c)
+#define IFMEM_BUSVERSION       IFMEM_WAKEUP
 #define IFMEM_DATA             (0x10)
 
 #define BUSCTRL_ATOFF(sc, off) ((uint32_t *)(sc->sc_busmem+(off)))
 
 #define BUSMEM_SIZE (1024*1024) /* need write throttling? */
+#define PKTLEN_SIZE 4
+
+/* just in case ... */
+static const uint32_t busversion = 1;
 
 static void shmif_rcv(void *);
 
@@ -185,10 +190,10 @@
 {
        uint32_t oldlen;
 
-       busread(sc, &oldlen, oldoff, 4);
+       busread(sc, &oldlen, oldoff, PKTLEN_SIZE);
        KASSERT(oldlen < BUSMEM_SIZE - IFMEM_DATA);
 
-       return advance(oldoff, 4 + oldlen);
+       return advance(oldoff, PKTLEN_SIZE + oldlen);
 }
 
 int
@@ -202,7 +207,7 @@
        int error;
 
        randnum = arc4random();
-       memcpy(&enaddr[2], &randnum, 4);
+       memcpy(&enaddr[2], &randnum, sizeof(randnum));
        mynum = atomic_inc_uint_nv(&numif)-1;
 
        sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
@@ -304,14 +309,14 @@
                lastoff = *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET);
 
                npktlenoff = nextpktoff(sc, lastoff);
-               dataoff = advance(npktlenoff, 4);
+               dataoff = advance(npktlenoff, PKTLEN_SIZE);
 
                for (m = m0; m != NULL; m = m->m_next) {
                        pktsize += m->m_len;
                        dataoff = buswrite(sc, dataoff, mtod(m, void *),
                            m->m_len);
                }
-               buswrite(sc, npktlenoff, &pktsize, 4);
+               buswrite(sc, npktlenoff, &pktsize, PKTLEN_SIZE);
                *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET) = npktlenoff;
                unlockbus(sc);
 
@@ -323,7 +328,8 @@
        }
        /* wakeup */
        if (wrote)
-               rumpuser_pwrite(sc->sc_memfd, &error, 4, IFMEM_WAKEUP, &error);
+               rumpuser_pwrite(sc->sc_memfd,
+                   &busversion, sizeof(busversion), IFMEM_WAKEUP, &error);
 }
 
 static void
@@ -376,8 +382,9 @@
                        continue;
                }
 
-               busread(sc, &pktlen, nextpkt, 4);
-               busread(sc, mtod(m, void *), advance(nextpkt, 4), pktlen);
+               busread(sc, &pktlen, nextpkt, PKTLEN_SIZE);
+               busread(sc, mtod(m, void *),
+                   advance(nextpkt, PKTLEN_SIZE), pktlen);
 
                DPRINTF(("shmif_rcv: read packet of length %d at %d\n",
                    pktlen, nextpkt));