freebsd with flexible iflib nic queues
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Andrew Gallatin 0617522889 Fix an alpha-only race which causes the transmit side of the chip to
lock up under moderate to heavy load.

The status & command fields share a 32-bit longword.  The programming
API of the eepro apparently requires that you update the command field
of a transmit slot that you've already given to the card.  This means
the card could be updating the status field of the same longword at
the same time. Since alphas can only operate on 32-bit chunks of
memory, both the status & command fields are loaded from memory &
operated on in registers when the following line of C is executed:

                sc->cbl_last->cb_command &= ~FXP_CB_COMMAND_S;

The race is caused by the card DMA'ing up the status at just the wrong
time -- after it has been loaded into a register & before it has been
written back.  The old value of the status is written back, clobbering
the status the card just DMA'ed up. The fact that the card has sent
this frame is missed & the transmit engine appears to hang.

Luckily, as numerous people on the freebsd-alpha list pointed out, the
load-locked/store-conditional instructions used by the atomic
functions work with respect changes in memory due to I/O devices.  We
now use them to safely update the command field.

Tested by: Bernd Walter <ticso@mail.cicely.de>
2000-07-19 14:33:52 +00:00
bin Update stale references to update(4) with references to the new 2000-07-19 07:39:08 +00:00
contrib fix conflicts 2000-07-19 13:56:18 +00:00
crypto Add missing $FreeBSD$ to files that are NOT still on vendor a branch. 2000-07-16 05:48:49 +00:00
etc Add some examples for IPv6 addresses. 2000-07-19 13:05:58 +00:00
games Don't call printf with no format string. 2000-07-10 05:24:02 +00:00
gnu Don't call fprintf() without a format string. 2000-07-12 00:59:32 +00:00
include Add -L to mtree 2000-07-16 08:19:49 +00:00
kerberos5 Unbreak heimdal build: we can no longer #include <netinet6/in6.h> 2000-07-06 10:09:59 +00:00
kerberosIV Remove the last vestiges of libRSAglue now that it's an empty stub. 2000-03-11 22:34:10 +00:00
lib Update stale references to update(4) with references to the new 2000-07-19 07:39:08 +00:00
libexec Don't reply "not a plain file" when the requested file doesn't exist. 2000-07-17 22:24:52 +00:00
release From the PR: 2000-07-19 00:05:59 +00:00
sbin Make "ifconfig" with no arguments equivalent to "ifconfig -a". 2000-07-18 22:07:31 +00:00
secure WITH_IDEA --> MAKE_IDEA fix. 2000-07-16 12:20:28 +00:00
share Remove mention of SYNCER_MAXDELAY and "thirty seconds", using more 2000-07-19 11:47:16 +00:00
sys Fix an alpha-only race which causes the transmit side of the chip to 2000-07-19 14:33:52 +00:00
tools Back out the previous change to the queue(3) interface. 2000-05-26 02:09:24 +00:00
usr.bin Braino: don't use passive mode unless the user requests it. 2000-07-19 09:12:36 +00:00
usr.sbin Describe the new VERSION and COMPILATIONDATE macros and mention that the 2000-07-19 10:14:00 +00:00
COPYRIGHT Update to add the July 22, 1999 addendum. 1999-09-05 21:33:47 +00:00
Makefile We have a new world order in libraries. 2000-02-24 23:03:16 +00:00
Makefile.inc1 Save any binaries we use by installworld, so that we won't use the 2000-07-19 04:41:59 +00:00
Makefile.upgrade $Id$ -> $FreeBSD$ 1999-08-28 01:35:59 +00:00
README $Id$ -> $FreeBSD$ 1999-08-28 01:35:59 +00:00
UPDATING Take jdp's excellent message to -current about the internat crypto 2000-07-16 06:00:40 +00:00

This is the top level of the FreeBSD source directory.  This file
was last revised on:
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For copyright information, please see the file COPYRIGHT in this
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documentation for which can be found at:
   http://www.freebsd.org/handbook/kernelconfig.html
And in the config(8) man page.

The sample kernel configuration files reside in the sys/i386/conf
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Source Roadmap:
---------------
bin		System/User commands.

contrib		Packages contributed by 3rd parties.

crypto		Export controlled stuff (see crypto/README).

etc		Template files for /etc

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gnu		Various commands and libraries under the GNU Public License.
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include		System include files.

kerberosIV	Kerberos package.

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sbin		System commands.

secure		DES and DES-related utilities - NOT FOR EXPORT!

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usr.sbin	System administration commands.


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