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>
Update/cleanup some definitions in tulip.h and tulip_core.c.
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>
Move tulip_select_media() processing to a workqueue, instead of
delaying in interrupt context, edited by Kyle McMartin to use kevent
thread, instead of creating its own workqueue.
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>
The obvious safe registers to read is one from PCI config space.
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>
As the cookie returned by pci_iomap() is fairly useless...
[Compile warning on pci_resource_start() format fixed up by Valerie
Henson.]
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>
This is needed if we wish to change the size of the resource structures.
Based on an original patch from Vivek Goyal <vgoyal@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
One thing this change pointed out was that we really should
pull the "get 'local-mac-address' property" logic into a helper
function all the network drivers can call.
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (51 commits)
[MIPS] Make timer interrupt frequency configurable from kconfig.
[MIPS] Correct HAL2 Kconfig description
[MIPS] Fix R4K cache macro names
[MIPS] Add Missing R4K Cache Macros to IP27 & IP32
[MIPS] Support for the RM9000-based Basler eXcite smart camera platform.
[MIPS] Support for the R5500-based NEC EMMA2RH Mark-eins board
[MIPS] Support SNI RM200C SNI in big endian mode and R5000 processors.
[MIPS] SN: include asm/sn/types.h for nasid_t.
[MIPS] Random fixes for sb1250
[MIPS] Fix bcm1480 compile
[MIPS] Remove support for NEC DDB5476.
[MIPS] Remove support for NEC DDB5074.
[MIPS] Cleanup memory managment initialization.
[MIPS] SN: Declare bridge_pci_ops.
[MIPS] Remove unused function alloc_pci_controller.
[MIPS] IP27: Extract pci_ops into separate file.
[MIPS] IP27: Use symbolic constants instead of magic numbers.
[MIPS] vr41xx: remove unnecessay items from vr41xx/Kconfig.
[MIPS] IP27: Cleanup N/M mode configuration.
[MIPS] IP27: Throw away old unused hacks.
...
A BIOS bug affecting some multiport tulip NICs requires an irq fixup
in tulip_core.c. This has only been enabled for i686, but it is
needed for x86_64 as well.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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>
This patch allows the tulip driver to suspend and resume properly. It was
originally written by Karsten Keil and then modified by Adam Belay.
Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Adam Belay <abelay@novell.com>
Signed-off-by: Andrew Morton <akpm@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!
David Howells