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)
i2c: Constify i2c_algorithm declarations, part 2
Make struct i2c_algorithm declarations const in all i2c bus drivers
where it is possible.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
platform_get_irq*() now returns on -ENXIO when the resource cannot be
found. Ensure all users of platform_get_irq*() handle this error
appropriately.
Signed-off-by: David Vrabel <dvrabel@arcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This allows us to eliminate the casts in the drivers, and eventually
remove the use of the device_driver function pointer methods for
platform device drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
Use kzalloc instead of kmalloc+memset in all remaining i2c bus and
chip drivers.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch updates the .owner field for various struct xxxx_driver variables,
other than pci_driver.
Signed-off-by: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Jean Delvare <khali@linux-fr>
Acked-by: Mark A. Greer <mgreer@mvista.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Deepak Saxena <dsaxena@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Merge the algorithm id part (16 upper bits) of the i2c adapters ids
into the definition of the adapters ids directly. After that, we don't
need to OR both ids together for each i2c_adapter structure.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are no more users of i2c_algorithm.id, so we can finally drop
this structure member.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The name member of the i2c_algorithm is never used, although all
drivers conscientiously fill it. We can drop it completely, this
structure doesn't need to have a name.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Seems that both Greg and I submitted the same patch and it just kept on
applying...
Cc: Greg KH <greg@kroah.com>
Cc: Kumar Gala <galak@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I2C-MPC: Restore code removed
A previous patch to remove support for the OCP device model was way
to generious and moved some of the platform device model code, oops.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A previous patch to remove support for the OCP device model was way to
generious and moved some of the platform device model code, oops.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
All consumers of the driver MPC10x, MPC52xx, MPC824x, MPC83xx, and MPC85xx are
all using platform devices. We can get ride of the dead code to support using
this driver with the old OCP based model
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
i2c: Race fix for i2c-mpc.c
The problem was that the clock speed and driver data is
initialized after the i2c adapter was added. This caused
the i2c bus to start working at a wrong speed. (Mostly
noticable on the second bus on mpc5200)
With this patch we've tried to keep the i2c adapter
working perfectly all the time it is included in the system.
Initialize before added, Remove garbage after deleleted.
Submitted-by: Asier Llano Palacios
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I2C-MPC: Allow for sharing of the interrupt line
On the MPC8548 devices we have multiple I2C-MPC buses however they are on the
same interrupt line. Made request_irq pass SA_SHIRQ now so the second bus can
register for the same IRQ.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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!
