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path: root/drivers/s390/net
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2006-11-30Fix misc .c/.h comment typosMatt LaPlante
Fix various .c/.h typos in comments (no code changes). Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-06[S390] irq change build fixes.Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-09-28[IPV4]: inet_addr_type() annotationsAl Viro
argument and inferred net-endian variables in callers annotated. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-28[S390] Inline assembly cleanup.Martin Schwidefsky
Major cleanup of all s390 inline assemblies. They now have a common coding style. Quite a few have been shortened, mainly by using register asm variables. Use of the EX_TABLE macro helps as well. The atomic ops, bit ops and locking inlines new use the Q-constraint if a newer gcc is used. That results in slightly better code. Thanks to Christian Borntraeger for proof reading the changes. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-09-17[PATCH] s390: qeth driver fixes [6/6]Frank Pavlic
[PATCH 9/9] s390: qeth driver fixes [6/6] From: Frank Pavlic <fpavlic@de.ibm.com> - Hipersockets has no IPV6 support, thus prevent issueing SETRTG_IPV6 control commands on Hipersockets devices. - fixed error handling in qeth_sysfs_(un)register Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: qeth driver fixes [5/6]Frank Pavlic
[PATCH 8/9] s390: qeth driver fixes [5/6] From: Frank Pavlic <fpavlic@de.ibm.com> fix kernel panic in qdio queue handling. qeth_qdio_clear_card() could be invoked by 2 CPUs simultaneously (for example reboot event and recovery). Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: qeth driver fixes [4/6]Frank Pavlic
[PATCH 7/9] s390: qeth driver fixes [4/6] From: Frank Pavlic <fpavlic@de.ibm.com> - fix kernel crash due to race, set card->state to SOFTSETUP after card and card->dev are initialized properly. - remove CONFIG_QETH_PERF_STATS, use sysfs attribute instead, as we want to have the ability to turn on/off the statistics at runtime. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: qeth driver fixes [3/6]Frank Pavlic
[PATCH 6/9] s390: qeth driver fixes [3/6] From: Frank Pavlic <fpavlic@de.ibm.com> fixed kernel panic caused by qeth driver: Using a bonding device qeth driver will realloc headroom for every skb coming from the bond device. Once this happens qeth frees the original skb and set the skb pointer to the new realloced skb. Under heavy transmit workload (e.g.UDP streams) through bond network device the qdio output queue might get full. In this case we return with EBUSY from qeth_send_packet. Returning to qeth_hard_start_xmit routine the skb address on the stack still points to the old address, which has been freed before. Returning from qeth_hard_start_xmit with EBUSY results in requeuing the skb. In this case it corrupts the qdisc queue and results in kernel panic. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: qeth driver fixes [2/6]Frank Pavlic
[PATCH 5/9] s390: qeth driver fixes [2/6] From: Frank Pavlic <fpavlic@de.ibm.com> - fixed error handling in create_device_attributes - fixed some minor bugs in IPv4 and IPv6 address checking Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: qeth driver fixes [1/6]Frank Pavlic
[PATCH 4/9] s390: qeth driver fixes [1/6] From: Frank Pavlic <fpavlic@de.ibm.com> - Drop incoming packets with vlan_tag set if card->vlangrp is not set. - use always vlan_hwaccel_rx to pass vlan frames to the stack. - fix recovery problem. Device was recovered properly but still not working. netif_carrier_on call right before recovery start fixes it. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: Makefile cleanupFrank Pavlic
[PATCH 3/9] s390: Makefile cleanup From: Frank Pavlic <fpavlic@de.ibm.com> remove CONFIG_MPC from Makefile which was introduced accidently in the past. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: netiucv driver fixesFrank Pavlic
[PATCH 2/9] s390: netiucv driver fixes From: Frank Pavlic <fpavlic@de.ibm.com> - missing lock initialization added - avoid duplicate iucv-interfaces to the same peer - rw-lock added for manipulating the list of defined iucv connections Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-09-17[PATCH] s390: minor s390 network driver fixesFrank Pavlic
Hi Jeff, this is a RESEND of the nine s390 network driver patches. I finally found that my kmail corrupted almost every patch I sent the last time. Please apply these 9 patches and forget about my first attempt! Sorry for the delay, I had some fights with sendmail, IMAP and mutt configuration. Frank [RESEND PATCH 1/9] s390: minor s390 network driver fixes From: Frank Pavlic <fpavlic@de.ibm.com> - iucv driver: use do { } while (0) constructs instead of empty defines to avoid compile bugs. - ctc driver: missing lock initialization added - lcs driver: BUG_ON usage was removed accidently with the last lcs patch. Put them back in place. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-08-19[PATCH] s390: fix arp_tbl lock usage in qethHeiko Carstens
qeth: bhs must be disabled when accessing neighbour tables. ================================= [ INFO: inconsistent lock state ] Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-07-18[S390] sysfs_create_xxx return values.Heiko Carstens
Take return values of sysfs_create_group & friends into account. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-07-12[S390] Fix sparse warnings.Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-07-10[PATCH] s390: broken null test in claw driverDave Jones
Whoops, better hope this never gets passed a null dev in its current state. Signed-off-by: Dave Jones <davej@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Holzheu <holzheu@de.ibm.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] fix oddball boolean logic in s390 netiucvDave Jones
Signed-off-by: Dave Jones <davej@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Andreas Herrmann <aherrman@de.ibm.com> Cc: Michael Holzheu <holzheu@de.ibm.com> Acked-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] s390: move var declarations behind ifdefSerge E. Hallyn
Two variables in drivers/s390/net/qeth_main.c:qeth_send_packet() are only used if CONFIG_QETH_PERF_STATS. Move their definition under the same ifdef to remove compiler warning. Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-08[NET] gso: Add skb_is_gsoHerbert Xu
This patch adds the wrapper function skb_is_gso which can be used instead of directly testing skb_shinfo(skb)->gso_size. This makes things a little nicer and allows us to change the primary key for indicating whether an skb is GSO (if we ever want to do that). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-03[PATCH] lockdep: annotate qeth driverHeiko Carstens
Annotate the qeth driver which uses a private skb-queue-head that is safely used in hardirq context too. Has no effect on non-lockdep kernels. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26[PATCH] drivers: use list_move()Akinobu Mita
This patch converts the combination of list_del(A) and list_add(A, B) to list_move(A, B) under drivers/. Acked-by: Corey Minyard <minyard@mvista.com> Cc: Ben Collins <bcollins@debian.org> Acked-by: Roland Dreier <rolandd@cisco.com> Cc: Alasdair Kergon <dm-devel@redhat.com> Cc: Gerd Knorr <kraxel@bytesex.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Frank Pavlic <fpavlic@de.ibm.com> Acked-by: Matthew Wilcox <matthew@wil.cx> Cc: Andrew Vasquez <linux-driver@qlogic.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[NET]: Merge TSO/UFO fields in sk_buffHerbert Xu
Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not going to scale if we add any more segmentation methods (e.g., DCCP). So let's merge them. They were used to tell the protocol of a packet. This function has been subsumed by the new gso_type field. This is essentially a set of netdev feature bits (shifted by 16 bits) that are required to process a specific skb. As such it's easy to tell whether a given device can process a GSO skb: you just have to and the gso_type field and the netdev's features field. I've made gso_type a conjunction. The idea is that you have a base type (e.g., SKB_GSO_TCPV4) that can be modified further to support new features. For example, if we add a hardware TSO type that supports ECN, they would declare NETIF_F_TSO | NETIF_F_TSO_ECN. All TSO packets with CWR set would have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO packets would be SKB_GSO_TCPV4. This means that only the CWR packets need to be emulated in software. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-26Merge branch 'upstream-fixes' into upstreamJeff Garzik
Conflicts: drivers/s390/net/ctctty.c
2006-05-26[netdrvr s/390] trim trailing whitespaceJeff Garzik
Previous fix patches added a bunch of trailing whitespace, which git-applymbox complained loudly about.
2006-05-26[PATCH] s390: lcs driver bug fixes and improvements [2/2]Klaus Wacker
This is the second lcs driver patch containing the rest of lcs fixes. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-05-26[PATCH] s390: lcs driver bug fixes and improvements [1/2]Klaus Wacker
Several problems occured with lcs device driver: - device not operational anymore after cable pull/plug-in. - unpredictable results occured, e.g. kernel panic using cards of type QD8F. - STOPLAN and delete multicast address command were not proper recognized by OSA card under heavy network workload. - channel/device error checks missing in interrupt handler. To fix all problems at once recovery of lcs devices has been improved. missing error checks in lcs interrupt handler has been added. Once a hardware problem occurs lcs will recover the device now properly. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-05-26[PATCH] s390: qeth driver fixesUrsula Braun
From: Frank Blaschka <Frank.Blaschka@de.ibm.com> From: Frank Pavlic <fpavlic@de.ibm.com> - fix fake_ll during initial device bringup. fake_ll was not active after first start of the device. Problem only occured when qeth was built without IPV6 support. - avoid skb usage after invocation of qeth_flush_buffers, because skb might already be freed. - remove yet another useless netif_wake_queue in qeth_softsetup_ipv6 since this function is only called when device is going online. In this case card->state will never be in state UP. So let the net_device queue down . Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-05-26[PATCH] s390: qeth driver fixesUrsula Braun
From: Frank Pavlic <fpavlic@de.ibm.com> - correct checking of sscanf-%n value in qeth_string_to_ipaddr(). - don't use netif_stop_queue outside the hard_start_xmit routine. Rather use netif_tx_disable. - don't call qeth_netdev_init on a recovery. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-05-26[PATCH] s390: minor fix in cu3088Cornelia Huck
In case of a parse error for the cu3088 group attribute, return -EINVAL instead of count. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-05-20Merge branch 'master' into upstreamJeff Garzik
2006-05-15[PATCH] s390: lcs incorrect testGreg Smith
While debugging why our LCS emulator is having some problems I noticed the following weirdness in drivers/s390/net/lcs.c routine lcs_irq. The `if' statement is always true since SCHN_STAT_PCI is defined as 0x80. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-02Merge branch 'master' into upstreamJeff Garzik
2006-05-01[PATCH] s390: make qeth buildableBastian Blank
Signed-off-by: Bastian Blank <bastian@waldi.eu.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Jeff Garzik <jeff@garzik.org> Acked-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-20[PATCH] s390: remove tty support from ctc network device driver [2/2]Frank Pavlic
Hi, here comes the second of the two patches ... Frank From: Peter Tiedemann <ptiedem@de.ibm.com> [2/2]: remove ctctty.c and ctctty.h files . Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-04-20[PATCH] s390: remove tty support from ctc network device driver [1/2]Frank Pavlic
Hi jeff, after the first shot I sent to you did not apply I resend two new patches I've made today to remove tty from ctc network driver. Please apply .... Thank you ... Frank From: Peter Tiedemann <ptiedem@de.ibm.com> [1/2]: tty support code will be removed from the ctc network device driver. Today we have a couple of alternatives which are performing much better. The second thing is that ctc should be a network device driver only. We should not mix tty and networking here. This first patch will remove the tty code from ctcmain.c . It also removes the build entry from the Makefile as well as TTY definitions from ctcmain.h. The second patch will remove two files, ctctty.c and ctctty.h. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-04-02BUG_ON() Conversion in drivers/s390/net/lcs.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-24[PATCH] s390: kzalloc() conversion in drivers/s390Eric Sesterhenn
Convert all kmalloc + memset sequences in drivers/s390 to kzalloc usage. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22Merge branch 'upstream-linus' of ↵Linus Torvalds
master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6 * 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6: [PATCH] Use of uninitialized variable in drivers/net/depca.c [PATCH] Use after free in net/tulip/de2104x.c [PATCH] sis900 adm7001 PHY support [PATCH] sky2: more ethtool stats [PATCH] s390: qeth :allow setting of attribute "route6" to "no_router". [PATCH] s390: qeth driver cleanups [PATCH] s390: qeth driver statistics fixes [PATCH] AMD Au1xx0: fix Ethernet TX stats [PATCH] fix spidernet build issue
2006-03-22[PATCH] s390: qeth :allow setting of attribute "route6" to "no_router".Frank Pavlic
[patch 4/6] s390: qeth :allow setting of attribute "route6" to "no_router". From: Ursula Braun <braunu@de.ibm.com> when setting route6 attribute back to no_router qeth does not issue an IP ASSIST command to reset router value to no_router. Once primary_router is set device stays in this mode. Issue an IP ASSIST command when no_router is set in route6. Device will be reset and thus will not longer run as a primary router. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> diffstat: qeth_main.c | 5 ----- 1 files changed, 5 deletions(-) Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-22[PATCH] s390: qeth driver cleanupsFrank Pavlic
[patch 3/6] s390: qeth driver cleanups From: Ursula Braun <braunu@de.ibm.com> - code analyzing tool BEAM has found some unreachable and unnecessary statements and also conditions which are always true. - removed some useless MII code since OSA card will never allow to set such values. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> diffstat: qeth_main.c | 49 ++++--------------------------------------------- qeth_proc.c | 18 +++++++++--------- qeth_sys.c | 2 +- 3 files changed, 14 insertions(+), 55 deletions(-) Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-22[PATCH] s390: qeth driver statistics fixesFrank Pavlic
[patch 2/6] s390: qeth driver statistics fixes From: Ursula Braun <braunu@de.ibm.com> - display "unsigned int" values in /proc/qeth_perf with %u instead of %i - omit qdio header length when increasing card->stats.tx_bytes Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> diffstat: qeth_main.c | 3 ++- qeth_proc.c | 38 +++++++++++++++++++------------------- 2 files changed, 21 insertions(+), 20 deletions(-) Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-22Fix "frist", "fisrt", typosUwe Zeisberger
Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-08[PATCH] s390: iucv message limit for smsgMartin Schwidefsky
The message limit on the iucv connect call for the smsg module is too low. Therefore increase the smsg message limit to 255. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-17[PATCH] s390: some qeth driver fixesFrank Pavlic
[patch 2/2] s390: some qeth driver fixes From: Frank Pavlic <fpavlic@de.ibm.com> - fixed kernel panic when using EDDP support in Layer 2 mode - NULL pointer exception in qeth_set_offline fixed. - setting EDDP in Layer 2 mode did not set NETIF_F_(SG/TSO) flags when device became online. - use sscanf for parsing and converting IPv4 addresses from string to __u8 values. - qeth_string_to_ipaddr6 fixed. in case of double colon the converted IPv6 address out from the string was not correct in previous implementation. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> diffstat: qeth.h | 112 +++++++++++++++++++++++++----------------------------------- qeth_eddp.c | 11 ++++- qeth_main.c | 17 +++------ 3 files changed, 63 insertions(+), 77 deletions(-) Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
2006-02-17[PATCH] s390: lcs performance enhancementsFrank Pavlic
[patch 1/2] s390: lcs performance enhancements From: Klaus Wacker <kdwacker@de.ibm.com> - When flood pinging (with large packet size) an LCS device, about 90 % of all packets are dropped by driver. - increased number of lcs IO buffers to 32. - use netif_stop_queue/netif_wake_queue in lcs_start_xmit routine - don't lock the whole xmit routine but just the piece of code where tx_buffer is touched. Signed-off-by: Frank Pavlic <fpavlic@de.ibm.com> diffstat: lcs.c | 31 +++++++++++++++++-------------- lcs.h | 2 +- 2 files changed, 18 insertions(+), 15 deletions(-) Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
2006-02-01[PATCH] s390: Remove CVS generated informationHeiko Carstens
- Remove all CVS generated information like e.g. revision IDs from drivers/s390 and include/asm-s390 (none present in arch/s390). - Add newline at end of arch/s390/lib/Makefile to avoid diff message. Acked-by: Andreas Herrmann <aherrman@de.ibm.com> Acked-by: Frank Pavlic <pavlic@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-14[PATCH] s390: email-address changeCornelia Huck
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10[PATCH] TTY layer buffering revampAlan Cox
The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>