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)
* More generi-fication of function/macro names where appropriate:
ax88772_xx() -> asix_xx()
* Reorder functions to provide more logical grouping
* AX88178 device support
* Support DLink DUB-E100 Rev B Support
* Hopefully resolve all endian-ness issues
* Use more defines for bitmask values
* Change a number of devdbg() calls to deverr() so that if DEBUG is not
defined, the error messages still get through as necessary
Signed-off-by: David Hollis <dhollis@davehollis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for detection and dworking with a ASIX 88178 based USB-Gigabit
adaptor. With the patch, it is detected and handled correctly by the asix
module.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the ASIX code is supporting more than just the AX88172 devices,
make the utility function names more generic: ax8817x_func -> asix_func.
Functions that are chip specific now indicate as such: ax88772_func.
Additionally, pull some common routines used in initialization and such
into simple functions to reduce the verbosity of certain functions such
as
the bind() routines and to make the error handling consistent across the
board.
Signed-off-by: David Hollis <dhollis@davehollis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add device IDs for the 0G0 Cable Ethernet device as reported by
Charles Lepple <clepple@gmail.com>.
Signed-off-by: David Hollis <dhollis@davehollis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Attached patch adds device IDs for the Linksys USB200M Rev 2 device
which uses the AX88772 chipset.
Signed-off-by: David Hollis <dhollis@davehollis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This lets us remove a lot of code in the drivers that were all checking
the same thing. It also found some bugs in a few of the drivers, which
has been fixed up.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch moves the ASIX AX8817x driver into its own file, just using
the "usbnet" infrastructure as a utility library.
- As with "cdc_subset" this involved minor Kconfig/kbuild tweaks,
moving code from one file to another, and exporting a few functions.
- This includes updates from Jamie Painter to add (and use) a new hook
to handle the different maximum transfer sizes for rx and tx sides.
- Also from Jamie, some bugfixes:
* MDIO byteorder (to address some PPC media negotiation problems);
* Force alignment at key spots when using ax88772 framing (on some
embedded hardware, the network stack will break otherwise);
* Address some link reset problems.
It also makes this driver use the standard (5 seconds vs half second)
control timeouts used elsewhere in USB; and wraps a few lines before
the 80th column (which previously needed it).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
David Howells