linux-toradex.git/kernel/irq/migration.c, branch tegra-9.12.13

cpumask: make irq_set_affinity() take a const struct cpumask

2008-12-13T10:50:26+00:00

Impact: change existing irq_chip API

Not much point with gentle transition here: the struct irq_chip's
setaffinity method signature needs to change.

Fortunately, not widely used code, but hits a few architectures.

Note: In irq_select_affinity() I save a temporary in by mangling
irq_desc[irq].affinity directly.  Ingo, does this break anything?

(Folded in fix from KOSAKI Motohiro)

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Reviewed-by: Grant Grundler 
Acked-by: Ingo Molnar 
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: jeremy@xensource.com
Cc: KOSAKI Motohiro

genirq: keep affinities set from userspace across free/request_irq()

2008-11-09T21:23:49+00:00

Impact: preserve user-modified affinities on interrupts

Kumar Galak noticed that commit
18404756765c713a0be4eb1082920c04822ce588 (genirq: Expose default irq
affinity mask (take 3))

overrides an already set affinity setting across a free /
request_irq(). Happens e.g. with ifdown/ifup of a network device.

Change the logic to mark the affinities as set and keep them
intact. This also fixes the unlocked access to irq_desc in
irq_select_affinity() when called from irq_affinity_proc_write()

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

generic: sparse irqs: use irq_desc() together with dyn_array, instead of irq_desc[]

2008-10-16T14:52:29+00:00

add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.

Preallocate 32 irq_desc, and irq_desc() will try to get more.

( No change in functionality is expected anywhere, except the odd build
  failure where we missed a code site or where a crossing commit itroduces
  new irq_desc[] usage. )

v2: according to Eric, change get_irq_desc() to irq_desc()

Signed-off-by: Yinghai Lu 
Signed-off-by: Ingo Molnar

[PATCH] genirq: Mask irqs when migrating them.

2007-02-26T18:34:08+00:00

move_native_irqs tries to do the right thing when migrating irqs
by disabling them.  However disabling them is a software logical
thing, not a hardware thing.  This has always been a little flaky
and after Ingo's latest round of changes it is guaranteed to not
mask the apic.

So this patch fixes move_native_irq to directly call the mask and
unmask chip methods to guarantee that we mask the irq when we
are migrating it.  We must do this as it is required by
all code that call into the path.

Since we don't know the masked status when IRQ_DISABLED is
set so we will not be able to restore it.   The patch makes the code
just give up and trying again the next time this routing is called.

Signed-off-by: Eric W. Biederman 
Acked-by: Suresh Siddha 
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] genirq: cleanup: merge pending_irq_cpumask[] into irq_desc[]

2006-06-29T17:26:22+00:00

Consolidation: remove the pending_irq_cpumask[NR_IRQS] array and move it into
the irq_desc[NR_IRQS].pending_mask field.

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: cleanup: reduce irq_desc_t use, mark it obsolete

2006-06-29T17:26:22+00:00

Cleanup: remove irq_desc_t use from the generic IRQ code, and mark it
obsolete.

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: cleanup: remove irq_descp()

2006-06-29T17:26:22+00:00

Cleanup: remove irq_descp() - explicit use of irq_desc[] is shorter and more
readable.

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] genirq: rename desc->handler to desc->chip

2006-06-29T17:26:21+00:00

This patch-queue improves the generic IRQ layer to be truly generic, by adding
various abstractions and features to it, without impacting existing
functionality.

While the queue can be best described as "fix and improve everything in the
generic IRQ layer that we could think of", and thus it consists of many
smaller features and lots of cleanups, the one feature that stands out most is
the new 'irq chip' abstraction.

The irq-chip abstraction is about describing and coding and IRQ controller
driver by mapping its raw hardware capabilities [and quirks, if needed] in a
straightforward way, without having to think about "IRQ flow"
(level/edge/etc.) type of details.

This stands in contrast with the current 'irq-type' model of genirq
architectures, which 'mixes' raw hardware capabilities with 'flow' details.
The patchset supports both types of irq controller designs at once, and
converts i386 and x86_64 to the new irq-chip design.

As a bonus side-effect of the irq-chip approach, chained interrupt controllers
(master/slave PIC constructs, etc.) are now supported by design as well.

The end result of this patchset intends to be simpler architecture-level code
and more consolidation between architectures.

We reused many bits of code and many concepts from Russell King's ARM IRQ
layer, the merging of which was one of the motivations for this patchset.

This patch:

rename desc->handler to desc->chip.

Originally i did not want to do this, because it's a big patch.  But having
both "desc->handler", "desc->handle_irq" and "action->handler" caused a
large degree of confusion and made the code appear alot less clean than it
truly is.

I have also attempted a dual approach as well by introducing a
desc->chip alias - but that just wasnt robust enough and broke
frequently.

So lets get over with this quickly.  The conversion was done automatically
via scripts and converts all the code in the kernel.

This renaming patch is the first one amongst the patches, so that the
remaining patches can stay flexible and can be merged and split up
without having some big monolithic patch act as a merge barrier.

[akpm@osdl.org: build fix]
[akpm@osdl.org: another build fix]
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds