Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
As I promised last week, here is the first pass at removing all
unnecessary printk's that exist in network device drivers currently in
promiscuous mode. The duplicate messages are not needed so they have
been removed. Some of these drivers are quite old and might not need an
update, but I did them all anyway.
I am currently auditing the remaining conditional printk's and will send
out a patch for those soon.
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Include "tulip.h" in winbond-840.c and clean up lots of redundant
definitions.
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
Signed-off-by: Valerie Henson <val_henson@linux.intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
From: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
With CONFIG_HOTPLUG=n it won't compile:
drivers/net/tulip/winbond-840.c:141: error: version causes a section type conflict
(For some reason it gets the same error if marked __initdata. Give up.)
Cc: Valerie Henson <val_henson@linux.intel.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Becker-derived drivers often have the 'io_size' member in their chip
info struct, indicating the minimum required size of the I/O resource
(usually a PCI BAR). For many situations, this number is either
constant or irrelevant (due to pci_iomap convenience behavior).
This change removes the io_size invariant member, and replaces it with a
compile-time constant.
Drivers updated: fealnx, gt96100eth, winbond-840, yellowfin
Additionally,
- gt96100eth: unused 'drv_flags' removed from gt96100eth
- winbond-840: unused struct match_info removed
- winbond-840: mark pci_id_tbl[] const, __devinitdata
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Symbols such as PCI_USES_IO, PCI_ADDR0, etc. originated from Donald
Becker's net driver template, but have been long unused. Remove.
In a few drivers, this allows the further eliminate of the pci_flags (or
just plain flags) member in the template driver probe structure.
Most of this logic is simply open-coded in most drivers, since it never
changes.
Made a few other cleanups while I was in there, too:
* constify, __devinitdata several PCI ID tables
* replace table terminating entries such as "{0,}," and "{NULL},"
with a more-clean "{ }".
Signed-off-by: Jeff Garzik <jeff@garzik.org>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (109 commits)
[ETHTOOL]: Fix UFO typo
[SCTP]: Fix persistent slowdown in sctp when a gap ack consumes rx buffer.
[SCTP]: Send only 1 window update SACK per message.
[SCTP]: Don't do CRC32C checksum over loopback.
[SCTP] Reset rtt_in_progress for the chunk when processing its sack.
[SCTP]: Reject sctp packets with broadcast addresses.
[SCTP]: Limit association max_retrans setting in setsockopt.
[PFKEYV2]: Fix inconsistent typing in struct sadb_x_kmprivate.
[IPV6]: Sum real space for RTAs.
[IRDA]: Use put_unaligned() in irlmp_do_discovery().
[BRIDGE]: Add support for NETIF_F_HW_CSUM devices
[NET]: Add NETIF_F_GEN_CSUM and NETIF_F_ALL_CSUM
[TG3]: Convert to non-LLTX
[TG3]: Remove unnecessary tx_lock
[TCP]: Add tcp_slow_start_after_idle sysctl.
[BNX2]: Update version and reldate
[BNX2]: Use CPU native page size
[BNX2]: Use compressed firmware
[BNX2]: Add firmware decompression
[BNX2]: Allow WoL settings on new 5708 chips
...
Manual fixup for conflict in drivers/net/tulip/winbond-840.c
Various drivers use xmit_lock internally to synchronise with their
transmission routines. They do so without setting xmit_lock_owner.
This is fine as long as netpoll is not in use.
With netpoll it is possible for deadlocks to occur if xmit_lock_owner
isn't set. This is because if a printk occurs while xmit_lock is held
and xmit_lock_owner is not set can cause netpoll to attempt to take
xmit_lock recursively.
While it is possible to resolve this by getting netpoll to use
trylock, it is suboptimal because netpoll's sole objective is to
maximise the chance of getting the printk out on the wire. So
delaying or dropping the message is to be avoided as much as possible.
So the only alternative is to always set xmit_lock_owner. The
following patch does this by introducing the netif_tx_lock family of
functions that take care of setting/unsetting xmit_lock_owner.
I renamed xmit_lock to _xmit_lock to indicate that it should not be
used directly. I didn't provide irq versions of the netif_tx_lock
functions since xmit_lock is meant to be a BH-disabling lock.
This is pretty much a straight text substitution except for a small
bug fix in winbond. It currently uses
netif_stop_queue/spin_unlock_wait to stop transmission. This is
unsafe as an IRQ can potentially wake up the queue. So it is safer to
use netif_tx_disable.
The hamradio bits used spin_lock_irq but it is unnecessary as
xmit_lock must never be taken in an IRQ handler.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Call pci_map_single() with the actual size of the receive
buffers, not 0 (which skb->len is initialized to by dev_alloc_skb()).
Signed-off-by: Erling A. Jacobsen <linuxcub@email.dk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
hi,
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized away
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
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>
The previous patch did not compile cleanly on all architectures so
here's a fixed one.
Use the DMA_32BIT_MASK constant from dma-mapping.h when calling
pci_set_dma_mask() or pci_set_consistent_dma_mask()
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
This fixes remaining u32s in drivers/ net.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
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!
