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)
Changes the obsolete Scsi_Cmnd to struct scsi_cmnd in the arm subdir
of the scsi-subsys.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Many files include the filename at the beginning, serveral used a wrong one.
Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
SCSI folk forgot to fix up all the uses of 'buffer' before deleting
this struct member. Do it for them to rescue the resulting build
failures.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This fixes three drivers to compile again after my patch that removes
the data_cmnd member from struct scsi_cmnd.
The fas216 change is trivial, it should have been using ->cmnd all the
time.
NCR53C9 (which seem to be mostly duplicate driver with esp.c!) is doing
something odd, it should only have looked at ->cmnd before not the saved
copy that is kept for the error handlers sake. Note that it really
should deal with the sync setting themselves but use the generic domain
validation code that get this right - but that's for later let's push
this simple compile fix for now.
And sorry for the late fix for this, I have been busy with OLS and
associated activities last week.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
MODULE_PARM was actually breaking: recent gcc version optimize them out as
unused. It's time to replace the last users, which are generally in the
most unloved drivers anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Many ARM drivers do not need to include asm/irq.h - remove this
unnecessary include from some ARM drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rename scsi_print_msg to spi_print_msg and move its prototype from
scsi_dbg.h to scsi_transport_spi.h
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
scsi_print_msg() is an SPI-specific concept. This patch moves it from
constants.c to scsi_transport_spi.c and updates the Kconfig to link in
the SPI class for the drivers which use scsi_print_msg().
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This is the drivers/scsi/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in drivers/scsi/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch uses sg_set_buf/sg_init_one in some places where it was
duplicated.
Signed-off-by: David Hardeman <david@2gen.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
acornscsi had been broken for a long time; marked as such
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Drivers need not implement a hook that returns FAILED, and does nothing
else, since the SCSI midlayer code will do that for us.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
these have been wrappers for the generic dma direction bits since 2.5.x.
This patch converts the few remaining drivers and removes the macros.
Arjan noticed there's some hunk in here that shouldn't. Updated patch
below:
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We have the scsi_print_* functions in the proper namespace for a long
time now and there weren't a lot users left.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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