linux-toradex.git/include/linux/irq.h, branch v2.6.20.21

[PATCH] genirq: clean up irq-flow-type naming, fix

2006-10-20T17:26:37+00:00

Re-add the set_irq_chip_and_handler() prototype, it's still widely used.

Signed-off-by: Ingo Molnar 
Cc: Olaf Hering 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: clean up irq-flow-type naming

2006-10-17T15:18:45+00:00

Introduce desc->name and eliminate the handle_irq_name() hack.  Add
set_irq_chip_and_handler_name() to set the flow type and name at once.

Signed-off-by: Ingo Molnar 
Acked-by: Thomas Gleixner 
Cc: "Eric W. Biederman" 
Cc: Matthew Wilcox 
Cc: Kyle McMartin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

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 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

IRQ: Typedef the IRQ flow handler function type

2006-10-05T12:28:06+00:00

Typedef the IRQ flow handler function type.

Signed-Off-By: David Howells 
(cherry picked from 8e973fbdf5716b93a0a8c0365be33a31ca0fa351 commit)

[PATCH] msi: simplify msi sanity checks by adding with generic irq code

2006-10-04T14:55:29+00:00

Currently msi.c is doing sanity checks that make certain before an irq is
destroyed it has no more users.

By adding irq_has_action I can perform the test is a generic way, instead of
relying on a msi specific data structure.

By performing the core check in dynamic_irq_cleanup I ensure every user of
dynamic irqs has a test present and we don't free resources that are in use.

In msi.c this allows me to kill the attrib.state member of msi_desc and all of
the assciated code to maintain it.

To keep from freeing data structures when irq cleanup code is called to soon
changing dyanamic_irq_cleanup is insufficient because there are msi specific
data structures that are also not safe to free.

Signed-off-by: Eric W. Biederman 
Cc: Ingo Molnar 
Cc: Tony Luck 
Cc: Andi Kleen 
Cc: Thomas Gleixner 
Cc: Greg KH 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: irq: remove msi hacks

2006-10-04T14:55:28+00:00

Because of the nasty way that CONFIG_PCI_MSI was implemented we wound up with
set_irq_info and set_native_irq_info, with move_irq and move_native_irq.  Both
functions did the same thing but they were built and called under different
circumstances.  Now that the msi hacks are gone we can kill move_irq and
set_irq_info.

Signed-off-by: Eric W. Biederman 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Benjamin Herrenschmidt 
Cc: Rajesh Shah 
Cc: Andi Kleen 
Cc: "Protasevich, Natalie" 
Cc: "Luck, Tony" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: irq: add a dynamic irq creation API

2006-10-04T14:55:27+00:00

With the msi support comes a new concept in irq handling, irqs that are
created dynamically at run time.

Currently the msi code allocates irqs backwards.  First it allocates a
platform dependent routing value for an interrupt the ``vector'' and then it
figures out from the vector which irq you are on.

This msi backwards allocator suffers from two basic problems.  The allocator
suffers because it is trying to do something that is architecture specific in
a generic way making it brittle, inflexible, and tied to tightly to the
architecture implementation.  The alloctor also suffers from it's very
backwards nature as it has tied things together that should have no
dependencies.

To solve the basic dynamic irq allocation problem two new architecture
specific functions are added: create_irq and destroy_irq.

create_irq takes no input and returns an unused irq number, that won't be
reused until it is returned to the free poll with destroy_irq.  The irq then
can be used for any purpose although the only initial consumer is the msi
code.

destroy_irq takes an irq number allocated with create_irq and returns it to
the free pool.

Making this functionality per architecture increases the simplicity of the irq
allocation code and increases it's flexibility.

dynamic_irq_init() and dynamic_irq_cleanup() are added to automate the
irq_desc initializtion that should happen for dynamic irqs.

Signed-off-by: Eric W. Biederman 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Benjamin Herrenschmidt 
Cc: Rajesh Shah 
Cc: Andi Kleen 
Cc: "Protasevich, Natalie" 
Cc: "Luck, Tony" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: irq: add moved_masked_irq

2006-10-04T14:55:26+00:00

Currently move_native_irq disables and renables the irq we are migrating to
ensure we don't take that irq when we are actually doing the migration
operation.  Disabling the irq needs to happen but sometimes doing the work is
move_native_irq is too late.

On x86 with ioapics the irq move sequences needs to be:
edge_triggered:
  mask irq.
  move irq.
  unmask irq.
  ack irq.
level_triggered:
  mask irq.
  ack irq.
  move irq.
  unmask irq.

We can easily perform the edge triggered sequence, with the current defintion
of move_native_irq.  However the level triggered case does not map well.  For
that I have added move_masked_irq, to allow me to disable the irqs around both
the ack and the move.

Q: Why have we not seen this problem earlier?

A: The only symptom I have been able to reproduce is that if we change
   the vector before acknowleding an irq the wrong irq is acknowledged.
   Since we currently are not reprogramming the irq vector during
   migration no problems show up.

   We have to mask the irq before we acknowledge the irq or else we could
   hit a window where an irq is asserted just before we acknowledge it.

   Edge triggered irqs do not have this problem because acknowledgements
   do not propogate in the same way.

Signed-off-by: Eric W. Biederman 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Benjamin Herrenschmidt 
Cc: Rajesh Shah 
Cc: Andi Kleen 
Cc: "Protasevich, Natalie" 
Cc: "Luck, Tony" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: irq: convert the move_irq flag from a 32bit word to a single bit

2006-10-04T14:55:26+00:00

The primary aim of this patchset is to remove maintenances problems caused by
the irq infrastructure.  The two big issues I address are an artificially
small cap on the number of irqs, and that MSI assumes vector == irq.  My
primary focus is on x86_64 but I have touched other architectures where
necessary to keep them from breaking.

- To increase the number of irqs I modify the code to look at the (cpu,
  vector) pair instead of just looking at the vector.

  With a large number of irqs available systems with a large irq count no
  longer need to compress their irq numbers to fit.  Removing a lot of brittle
  special cases.

  For acpi guys the result is that irq == gsi.

- Addressing the fact that MSI assumes irq == vector takes a few more
  patches.  But suffice it to say when I am done none of the generic irq code
  even knows what a vector is.

In quick testing on a large Unisys x86_64 machine we stumbled over at least
one driver that assumed that NR_IRQS could always fit into an 8 bit number.
This driver is clearly buggy today.  But this has become a class of bugs that
it is now much easier to hit.

This patch:

This is a minor space optimization.  In practice I don't think this has any
affect because of our alignment constraints and the other fields but there is
not point in chewing up an uncessary word and since we already read the flag
field this should improve the cache hit ratio of the irq handler.

Signed-off-by: Eric W. Biederman 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Benjamin Herrenschmidt 
Cc: Rajesh Shah 
Cc: Andi Kleen 
Cc: "Protasevich, Natalie" 
Cc: "Luck, Tony" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] FRV: permit __do_IRQ() to be dispensed with

2006-09-26T15:48:53+00:00

Permit __do_IRQ() to be dispensed with based on a configuration option.

Signed-off-by: David Howells 
Cc: Benjamin Herrenschmidt 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds