Date: Thu, 06 Sep 2001 17:49:06 -0700 From: Julian Elischer <julian@vicor-nb.com> To: current@freebsd.org Subject: RFC: hack volatile bzero and bcopy Message-ID: <3B981982.4E939CDF@vicor-nb.com>
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Here is a hack to remove the 20 or so warning messages from if_ie.c
Most of them are due to the supply of volatile pointers to bcopy and
bzero.
I do the following to produce macros that call bzero and bcopy, but
don't produce
warning messages when called with volatile arguments.
typedef void Xcopy( void volatile *, void volatile *, int);
#define VBCOPY(A,B,L) (*(Xcopy *)&bcopy)((A),(B),(L))
typedef void Xzero( void volatile *, int);
#define VBZERO(A,L) (*(Xzero *)&bzero)((A),(L))
This is kind-of a hack but a couple of things come to mind:
1/ Most drivers should probably use volatile mor ethan they do if they
share
structures with hardware. These often need bcopy(), so this is probably
not an unlikely
combination..
2/ initializing these volatile structures with bzero is also not
unlikely.
3/ It probably wouldn't hurt if bzero ALWAYS had a volatile pointer
argument.
and it may remove several warnings in other drivers as well.
questions:
Is this hack to horrible to contemplate?
Is it a reasonable thing thing to define bzero to take a volatile
argument.
(It does not hurt to pass a nonvolatile argument to a volatile but the
reverse
produces an error message). I've compiled LINT with this change and it
compiles fine.
Should we define an "official" volatile_bcopy() to use in these cases,
even if it is just a (nicer) version of this hack in systm.h?
BTW what is ovbcopy() for? is it for overlaping?
I can't find a definition for it here, but google finds references in
true64.
(overlapping)
I notice that KAME ar the major users of it, and it's defined to be the
same as
bcopy..
I also notice that NetBSD are (or were) having a kill
ovbcopy/bcopy/bzero effort
to replace them with memcpy and friends.
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--- if_ie.c Thu Sep 6 17:05:12 2001
+++ if_ie.c.new Thu Sep 6 17:03:42 2001
@@ -62,6 +62,10 @@
* Intel EtherExpress 16 support from if_ix.c, written by Rodney W. Grimes.
*/
+typedef void Xcopy( void volatile *, void volatile *, int);
+#define VBCOPY(A,B,L) (*(Xcopy *)&bcopy)((A),(B),(L))
+typedef void Xzero( void volatile *, int);
+#define VBZERO(A,L) (*(Xzero *)&bzero)((A),(L))
/*
* The i82586 is a very versatile chip, found in many implementations.
* Programming this chip is mostly the same, but certain details differ
@@ -219,9 +223,10 @@
/*
* This tells the autoconf code how to set us up.
*/
+static char drivername[] = "ie";
struct isa_driver iedriver = {
INTR_TYPE_NET,
- ieprobe, ieattach, "ie"
+ ieprobe, ieattach, drivername
};
enum ie_hardware {
@@ -776,7 +781,7 @@
ifp->if_softc = ie;
ifp->if_unit = unit;
- ifp->if_name = iedriver.name;
+ ifp->if_name = drivername;
ifp->if_mtu = ETHERMTU;
printf("ie%d: <%s R%d> address %6D\n", unit,
ie_hardware_names[ie->hard_type],
@@ -1140,7 +1145,7 @@
/*
* Snarf the Ethernet header.
*/
- bcopy((v_caddr_t) ie->cbuffs[i], (caddr_t) ehp, sizeof *ehp);
+ VBCOPY(ie->cbuffs[i], (caddr_t) ehp, sizeof *ehp);
/* ignore cast-qual warning here */
/*
@@ -1228,7 +1233,7 @@
if (thislen > m->m_len - thismboff) {
int newlen = m->m_len - thismboff;
- bcopy((v_caddr_t) (ie->cbuffs[head] + offset),
+ VBCOPY((v_caddr_t) (ie->cbuffs[head] + offset),
mtod(m, v_caddr_t) +thismboff, (unsigned) newlen);
/* ignore cast-qual warning */
m = m->m_next;
@@ -1245,7 +1250,7 @@
* pointers, and so on.
*/
if (thislen < m->m_len - thismboff) {
- bcopy((v_caddr_t) (ie->cbuffs[head] + offset),
+ VBCOPY((v_caddr_t) (ie->cbuffs[head] + offset),
mtod(m, caddr_t) +thismboff, (unsigned) thislen);
thismboff += thislen; /* we are this far into the
* mbuf */
@@ -1257,7 +1262,7 @@
* buffer's contents into the current mbuf. Do the
* combination of the above actions.
*/
- bcopy((v_caddr_t) (ie->cbuffs[head] + offset),
+ VBCOPY((v_caddr_t) (ie->cbuffs[head] + offset),
mtod(m, caddr_t) + thismboff, (unsigned) thislen);
m = m->m_next;
thismboff = 0; /* new mbuf, start at the beginning */
@@ -1300,7 +1305,7 @@
struct mbuf *m = 0;
struct ether_header eh;
- bcopy((v_caddr_t) (ie->rframes[num]), &rfd,
+ VBCOPY((v_caddr_t) (ie->rframes[num]), &rfd,
sizeof(struct ie_recv_frame_desc));
/*
@@ -1400,12 +1405,11 @@
len = 0;
for (m0 = m; m && len < IE_BUF_LEN; m = m->m_next) {
- bcopy(mtod(m, caddr_t), buffer, m->m_len);
+ VBCOPY(mtod(m, caddr_t), buffer, m->m_len);
buffer += m->m_len;
len += m->m_len;
}
- m_freem(m0);
len = max(len, ETHER_MIN_LEN);
/*
@@ -1413,9 +1417,9 @@
* packet before we commit it to the wire.
*/
if (ie->arpcom.ac_if.if_bpf)
- bpf_tap(&ie->arpcom.ac_if,
- (void *)ie->xmit_cbuffs[ie->xmit_count], len);
+ bpf_mtap(&ie->arpcom.ac_if, m0);
+ m_freem(m0);
ie->xmit_buffs[ie->xmit_count]->ie_xmit_flags =
IE_XMIT_LAST|len;
ie->xmit_buffs[ie->xmit_count]->ie_xmit_next = 0xffff;
@@ -1468,7 +1472,7 @@
scp = (volatile struct ie_sys_conf_ptr *) (uintptr_t)
(realbase + IE_SCP_ADDR);
- bzero((volatile char *) scp, sizeof *scp);
+ VBZERO(scp, sizeof *scp);
/*
* First we put the ISCP at the bottom of memory; this tests to make
@@ -1477,10 +1481,10 @@
* operation.
*/
iscp = (volatile struct ie_int_sys_conf_ptr *) where;
- bzero((volatile char *)iscp, sizeof *iscp);
+ VBZERO(iscp, sizeof *iscp);
scb = (volatile struct ie_sys_ctl_block *) where;
- bzero((volatile char *)scb, sizeof *scb);
+ VBZERO(scb, sizeof *scb);
scp->ie_bus_use = ie_softc[unit].bus_use; /* 8-bit or 16-bit */
scp->ie_iscp_ptr = (caddr_t) (uintptr_t)
@@ -1505,7 +1509,7 @@
iscp = (void *) Align((caddr_t) (uintptr_t)
(realbase + IE_SCP_ADDR -
sizeof(struct ie_int_sys_conf_ptr)));
- bzero((volatile char *) iscp, sizeof *iscp); /* ignore cast-qual */
+ VBZERO(iscp, sizeof *iscp); /* ignore cast-qual */
scp->ie_iscp_ptr = (caddr_t) (uintptr_t)
((volatile char *) iscp - (volatile char *) (uintptr_t) realbase);
@@ -1750,7 +1754,7 @@
command_and_wait(int unit, int cmd, volatile void *pcmd, int mask)
{
volatile struct ie_cmd_common *cc = pcmd;
- volatile int timedout = 0;
+ int timedout = 0;
struct callout_handle ch;
ie_softc[unit].scb->ie_command = (u_short) cmd;
@@ -1863,7 +1867,7 @@
/* First lay them out */
for (i = 0; i < ie->nframes; i++) {
ie->rframes[i] = rfd;
- bzero((volatile char *) rfd, sizeof *rfd); /* ignore cast-qual */
+ VBZERO( rfd, sizeof *rfd); /* ignore cast-qual */
rfd++;
}
@@ -1887,7 +1891,7 @@
for (i = 0; i < ie->nrxbufs; i++) {
ie->rbuffs[i] = rbd;
- bzero((volatile char *)rbd, sizeof *rbd);
+ VBZERO(rbd, sizeof *rbd);
ptr = Alignvol(ptr + sizeof *rbd);
rbd->ie_rbd_length = IE_RBUF_SIZE;
rbd->ie_rbd_buffer = MK_24(MEM, ptr);
@@ -1937,7 +1941,7 @@
cmd->com.ie_cmd_link = 0xffff;
/* ignore cast-qual */
- bcopy((v_caddr_t) ie->mcast_addrs, (v_caddr_t) cmd->ie_mcast_addrs,
+ VBCOPY(ie->mcast_addrs, cmd->ie_mcast_addrs,
ie->mcast_count * sizeof *ie->mcast_addrs);
cmd->ie_mcast_bytes = ie->mcast_count * 6; /* grrr... */
@@ -2001,8 +2005,8 @@
cmd->com.ie_cmd_cmd = IE_CMD_IASETUP | IE_CMD_LAST;
cmd->com.ie_cmd_link = 0xffff;
- bcopy((volatile char *)ie_softc[unit].arpcom.ac_enaddr,
- (volatile char *)&cmd->ie_address, sizeof cmd->ie_address);
+ VBCOPY(ie_softc[unit].arpcom.ac_enaddr,
+ &cmd->ie_address, sizeof cmd->ie_address);
scb->ie_command_list = MK_16(MEM, cmd);
if (command_and_wait(unit, IE_CU_START, cmd, IE_STAT_COMPL)
|| !(cmd->com.ie_cmd_status & IE_STAT_OK)) {
@@ -2051,8 +2055,8 @@
ie->xmit_cbuffs[ie->ntxbufs - 1] = (volatile void *) ptr;
for (i = 1; i < ie->ntxbufs; i++) {
- bzero((v_caddr_t) ie->xmit_cmds[i], sizeof *ie->xmit_cmds[i]);
- bzero((v_caddr_t) ie->xmit_buffs[i], sizeof *ie->xmit_buffs[i]);
+ VBZERO(ie->xmit_cmds[i], sizeof *ie->xmit_cmds[i]);
+ VBZERO(ie->xmit_buffs[i], sizeof *ie->xmit_buffs[i]);
}
/*
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