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)
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>
- Add new SA_PROBEIRQ which suppresses the new sharing-mismatch warning.
Some drivers like to use request_irq() to find an unused interrupt slot.
- Use it in i82365.c
- Kill unused SA_PROBE.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use the new platform_device helpers in the i82365 driver to get rid of the
"device 'i823650' does not have a release() function" warning, and to solve
bug #3676.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
The i82365 driver does not release all the resources when the device is not
found. This can cause an oops when reading /proc/ioports after module
unload.
Signed-off-by: Igor Popik <igor.popik@gmail.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
In PM v1, all devices were called at SUSPEND_DISABLE level. Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level. However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.
Since this is obsolete infrastructure which is no longer necessary,
we can remove it. Here's an (untested) patch to do exactly that.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
As a follow-up, remove the inclusion of pcmcia/version.h in many files.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f354942cb301fed273f423fb5c4f57bde3efc5b2
converted the check_region() calls in drivers/pcmcia/i82365.c into
request_regions. Unfortunately this seems to have broken things.
isa_probe() used to call check_region() and then call add_pcic() which would
request_region().
Now isa_probe() calls request_region() and then calls add_pcic() which calls
request_region() again, this fails and add_pcic() returns immediately without
doing all the setup etc.
On the face of it the patch below fixes the problem, by not doing the second
request region in add_pcic(). I think this is preferable to remove the call
in isa_probe() since identify() touches the I/O regions and is called before
add_pcic().
However I haven't fully grokked the meaning of the code which follows the
request_region() in isa_probe(), so I'm not sure that the handling WRT
multiple sockets and multiple bridge chips is correct. In particular I'm not
convinced that the regions for subsequent sockets and/or bridges will be
requested at all. I suspect a more thorough reworking by someone who
understands what is going on there might be in order.
I should mention that I'm actually messing about with this on an ARM platform
with wacky memory and i/o mapping offsets etc, it doesn't quite work yet for
other reasons which preclude full testing etc, but I think the problem above
is still present for more normal x86 stuff.
Signed-off-by: Ian Campbell <icampbell@arcom.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
randy_dunlap <rdunlap@xenotime.net>
Convert deprecated check_region() calls to request/release region.
Add return value check on one request_region().
I suspect that it may do an extra release_region(), which should
generate a warning message from the kernel.
Signed-off-by: randy_dunlap <rdunlap@xenotime.net>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
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!
