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>
Since version 4.1 the gcc is warning about ignored attributes. This patch is
using the equivalent attribute on the struct instead of on each of the
structure or union members.
GCC Manual:
"Specifying Attributes of Types
packed
This attribute, attached to struct or union type definition, specifies
that
each member of the structure or union is placed to minimize the memory
required. When attached to an enum definition, it indicates that the
smallest integral type should be used.
Specifying this attribute for struct and union types is equivalent to
specifying the packed attribute on each of the structure or union
members."
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Ignore all files generated from *_shipped files, plus a few others.
Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
"grep "lmc_prot\." -r ." didn't show anything.
lmc_proto.h seems to have the correct prototypes, and is actually used.
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
As we are currently unable to fix the problem with carrier and protocol
state signaling in net core I've to disable netif_carrier_off()
calls used by WAN protocol drivers. The attached patch should make
them working again.
The remaining netif_carrier_*() calls in hdlc_fr.c are fine as they
don't touch the physical device.
Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The previous patch adding the ability to nest struct class_device
changed the paramaters to the call class_device_create(). This patch
fixes up all in-kernel users of the function.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The following patch renames __in_dev_get() to __in_dev_get_rtnl() and
introduces __in_dev_get_rcu() to cover the second case.
1) RCU with refcnt should use in_dev_get().
2) RCU without refcnt should use __in_dev_get_rcu().
3) All others must hold RTNL and use __in_dev_get_rtnl().
There is one exception in net/ipv4/route.c which is in fact a pre-existing
race condition. I've marked it as such so that we remember to fix it.
This patch is based on suggestions and prior work by Suzanne Wood and
Paul McKenney.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following commit breaks cisco mode with my WAN drivers:
author David S. Miller <davem@davemloft.net>
Tue, 28 Jun 2005 22:25:31 +0000 (15:25 -0700)
commit 689be43945
"[NET]: Remove gratuitous use of skb->tail in network drivers."
The following patch fixes it - please apply (cisco_hard_header does
skb_push(4 bytes)).
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch contains possible cleanups including the following:
- make needlessly global code static
- #if 0 the following unused global function:
- sdladrv.c: sdla_intde
- remove the following unused global variable:
- lmc_media.c: lmc_t1_cables
- remove the following unneeded EXPORT_SYMBOL's:
- cycx_drv.c: cycx_inten
- sdladrv.c: sdla_inten
- sdladrv.c: sdla_intde
- sdladrv.c: sdla_intack
- sdladrv.c: sdla_intr
- syncppp.c: sppp_input
- syncppp.c: sppp_change_mtu
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Replace the custom is_digit()/is_hex_digit() macros with
isdigit()/isxdigit() from <linux/ctype.h> Additionaly remove unused macro
is_alpha() from <linux/wanpipe.h>
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Use schedule_timeout_interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Bonding just wants the device before the skb_bond()
decapsulation occurs, so simply pass that original
device into packet_type->func() as an argument.
It remains to be seen whether we can use this same
exact thing to get rid of skb->input_dev as well.
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the "list" member of struct sk_buff, as it is entirely
redundant. All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.
Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Use msleep_interruptible() instead of delay_cycx() to guarantee the task
delays as expected. Remove the prototype and definition of delay_cycx().
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
From: Marcelo Feitoza Parisi <marcelo@feitoza.com.br>
Use of the time_after() macro, defined at linux/jiffies.h, which deal
with wrapping correctly and are nicer to read.
Signed-off-by: Marcelo Feitoza Parisi <marcelo@feitoza.com.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
tr_type_trans(), hippi_type_trans() left as-is.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many drivers use skb->tail unnecessarily.
In these situations, the code roughly looks like:
dev = dev_alloc_skb(...);
[optional] skb_reserve(skb, ...);
... skb->tail ...
But even if the skb_reserve() happens, skb->data equals
skb->tail. So it doesn't make any sense to use anything
other than skb->data in these cases.
Another case was the s2io.c driver directly mucking with
the skb->data and skb->tail pointers. It really just wanted
to do an skb_reserve(), so that's what the code was changed
to do instead.
Another reason I'm making this change as it allows some SKB
cleanups I have planned simpler to merge. In those cleanups,
skb->head, skb->tail, and skb->end pointers are removed, and
replaced with skb->head_room and skb->tail_room integers.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Insert set_current_state() before schedule_timeout() so the
function delays as expected. Without the addition, schedule_timeout()
will return immediately.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Maximilian Attems <janitor@sternwelten.at>
Signed-off-by: Domen Puncer <domen@coderock.org>
Use the DMA_{64,32}BIT_MASK constants from dma-mapping.h when calling
pci_set_dma_mask() or pci_set_consistent_dma_mask()
This patch includes dma-mapping.h explicitly because it caused errors
on some architectures otherwise.
See http://marc.theaimsgroup.com/?t=108001993000001&r=1&w=2 for details
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Domen Puncer <domen@coderock.org>
wanpipe.txt and wan-router.txt in Documentation/networking contain the exact
same information (diff between the two shows no drivers/net/wan/Kconfig.
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch updates generic HDLC to version 1.18.
FR Cisco LMI production-tested. Please apply to Linux 2.6. Thanks.
Changes:
- doc updates
- added Cisco LMI support to Frame-Relay code
- cleaned hdlc_fr.c a bit, removed some orphaned #defines etc.
- fixed a problem with non-functional LMI in FR DCE mode.
- changed diagnostic messages to better conform to FR standards
- all protocols: information about carrier changes (DCD line) is now
printed to kernel logs.
Signed-Off-By: Krzysztof Halasa <khc@pm.waw.pl>
Drivers that expect ISA DMA API are marked as such in Kconfig.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kfree(0) is perfectly valid, checking pointers for NULL before calling
kfree() on them is redundant. The patch below cleans away a few such
redundant checks (and while I was around some of those bits I couldn't
stop myself from making a few tiny whitespace changes as well).
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Acked-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Call pci_enable_device() before looking at IRQ and resources,
and pci_disable_device() when shutting the interface down.
The driver requires this fix or the "pci=routeirq" workaround
on 2.6.10 and later kernels.
Reported and tested by Artur Lipowski.
From: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
