PPI handling is a bit of an odd beast. It uses its own low level
handling code and is hardwired to the local timers (hence lacking
a registration interface).

Instead, switch the low handling to the normal SPI handling code.
PPIs are handled by the handle_percpu_devid_irq flow.

This also allows the removal of some duplicated code.

Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NDavid Brown <davidb@codeaurora.org>
Tested-by: NDavid Brown <davidb@codeaurora.org>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The definition of __exception_irq_entry for
CONFIG_FUNCTION_GRAPH_TRACER=y needs linux/ftrace.h, but this creates a
circular dependency with it's current home in asm/system.h. Create
asm/exception.h and update all current users.

v4:	- rebase to rmk/for-next
v3:	- remove redundant includes of linux/ftrace.h
v2:	- document the usage restricitions of __exception*

Cc: Zoltan Devai <zdevai@gmail.com>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Our selection of interrupts to consider for IRQ migration is sub-
standard.  We were potentially including per-CPU interrupts in our
migration strategy, but omitting chained interrupts.  This caused
some interrupts to remain on a downed CPU.

We were also trying to migrate interrupts which were not migratable,
resulting in an OOPS.

Instead, iterate over all interrupts, skipping per-CPU interrupts
or interrupts whose affinity does not include the downed CPU, and
attempt to set the affinity for every one else if their chip
implements irq_set_affinity().
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now that the GIC takes care of selecting a target interrupt from the
affinity mask, we don't need all this complexity in the core code
anymore.  Just detect when we need to break affinity.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

irqdesc's node member is supposed to mark the numa node number for the
interrupt.  Our use of it is non-standard.  Remove this, replacing the
functionality with a test of the affinity mask.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On Mon, Jul 11, 2011 at 3:52 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:

...

> The __exception annotation on a function causes this to happen:
>
> [<c002406c>] (asm_do_IRQ+0x6c/0x8c) from [<c0024b84>]
> (__irq_svc+0x44/0xcc)
> Exception stack(0xc3897c78 to 0xc3897cc0)
> 7c60:                                                       4022d320 4022e000
> 7c80: 08000075 00001000 c32273c0 c03ce1c0 c2b49b78 4022d000 c2b420b4 00000001
> 7ca0: 00000000 c3897cfc 00000000 c3897cc0 c00afc54 c002edd8 00000013 ffffffff
>
> Where that stack dump represents the pt_regs for the exception which
> happened.  Any function found in while unwinding will cause this to
> be printed.
>
> If you insert a C function between the IRQ assembly and asm_do_IRQ,
> the
> dump you get from asm_do_IRQ will be the stack for your function,
> not
> the pt_regs.  That makes the feature useless.
>

When __irq_svc - or any of the other exception handling assembly code -
calls the C code, the stack pointer will be pointing at the pt_regs
structure.

All the entry points into C code from the exception handling code are
marked with __exception or __exception_irq_enter to indicate that they
are one of the functions which has pt_regs above them.

Normally, when you've entered asm_do_IRQ() you will have this stack
layout (higher address towards top):

       pt_regs
       asm_do_IRQ frame

If you insert a C function between the exception assembly code and
asm_do_IRQ, you end up with this stack layout instead:

       pt_regs
       your function frame
       asm_do_IRQ frame

This means when we unwind, we'll get to asm_do_IRQ, and rather than
dumping out the pt_regs, we'll dump out your functions stack frame
instead, because that's what is above the asm_do_IRQ stack frame
rather than the expected pt_regs structure.

The fix is to introduce handle_IRQ() for no exception stack dump, so
it can be called with MULTI_IRQ_HANDLER is selected and a C function
is between the assembly code and the actual IRQ handling code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>

Use the generic version and just keep the arch specific output.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use the proper accessor function instead of fiddling in the status
bits directly.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org

Ensure appropriate locks are taken to ensure that IRQ migration off
the current CPU is race-free.  We may have a concurrent set_affinity
via procfs running on another CPU in parallel with the IRQ migration,
resulting in unpredictable results.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The force argument to irq_set_affinity really should be 'true' as
moving IRQs off a CPU which is going down isn't optional.
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NLennert Buytenhek <buytenh@secretlab.ca>

Rather than storing each machine init hook separately, store a
pointer to the machine description record and dereference this
instead.  This pointer is only available while the init sections
are present, which is not a problem as we only use it from init
code.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This separates out the individual IPI interrupt counts from the
total IPI count, which allows better visibility of what IPIs are
being used for.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As per x86, align the initial column according to how many IRQs we
have.  Also, provide an english explaination for the 'LOC:' and
'IPI:' lines.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When FUNCTION_GRAPH_TRACER is enabled, place do_IRQ() and friends in the
IRQ_ENTRY section so that the irq-related features of the function graph
tracer work.
Signed-off-by: NRabin Vincent <rabin@rab.in>

The core code now initializes the requested number of interrupts and
sets the flags in irq_desc.status which are requested by the
architecture via ARCH_IRQ_INIT_FLAGS.

Add ARCH_IRQ_INIT_FLAGS and remove the loop which sets those flags
after the irq descriptors are allocated.

[ This patch should have been in the original irq rework and got
  dropped accidentaly ]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Anand Gadiyar <gadiyar@ti.com>

Commit b683de2b in linux-next as of 20101014 (genirq: Query
arch for number of early descriptors) seems to have broken
bootup on several ARM boards - my beagleboard gives the
following dump with earlyprintk:

 NR_IRQS:402
 Unable to handle kernel NULL pointer dereference at virtual
 address 00000028 pgd = c0004000
 [00000028] *pgd=00000000
 Internal error: Oops: 5 [#1]
 last sysfs file:
 Modules linked in:
 CPU: 0    Not tainted
 (2.6.36-rc7-next-20101014-linux-next-20101012+ #40) PC is at
 init_IRQ+0x14/0x48 LR is at start_kernel+0x150/0x2c0
 [...]

We seem to be using desc->status without assigning desc to
anything. Fix this by adding back the code that was originally
there.
Signed-off-by: NAnand Gadiyar <gadiyar@ti.com>
Tested-by: NLinus Walleij <linus.walleij@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
LKML-Reference: <1287077397-21781-1-git-send-email-gadiyar@ti.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go
ahead and allocate more.

Use the unused return value of arch_probe_nr_irqs() to let the
architecture return the number of early allocations. Fix up all users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

So to allow NR_IRQS to be dynamic and platforms to specify the number
of IRQs really needed.
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

The show_fiq_list() call in arch/arm/kernel/irq.c currently depends on
CONFIG_ARCH_ACORN, but this is not the only architecture that supports
the usage of FIQ. Change to calling this if CONFIG_FIQ is set (which
is what arch/arm/kernel/fiq.c is built by).
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

handle_bad_irq() expects the IRQ number to be valid (used for statistics),
so it cannot be called with an illegal vector. The problem was reported
by a static analysis tool.

The change makes bad_irq_desc redundant, so delete it.
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The cpu member of struct irq_desc was recently renamed to node. The
patch renames the ARM references to the old member.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

SPIN_LOCK_UNLOCKED is deprecated as lockdep cannot properly work with
locks initialized with it.

This fix is necessary to compile the linux-rt tree for ARM.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Steven Rostedt <srostedt@redhat.com>

Impact: cleanup, update to new cpumask API

Irq_desc.affinity and irq_desc.pending_mask are now cpumask_var_t's
so access to them should be using the new cpumask API.
Signed-off-by: NMike Travis <travis@sgi.com>

so we could move kstat_irqs array to irq_desc struct.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

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: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Reviewed-by: NGrant Grundler <grundler@parisc-linux.org>
Acked-by: NIngo Molnar <mingo@redhat.com>
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: jeremy@xensource.com
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

desc_handle_irq() was declared as obsolete since long ago.
Replace it with generic_handle_irq()
Signed-off-by: NDmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Lots of places in arch/arm were needlessly including linux/ptrace.h,
resumably because we used to pass a struct pt_regs to interrupt
handlers.  Now that we don't, all these ptrace.h includes are
redundant.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now that disable_irq() defaults to delayed-disable semantics, the IRQ_DISABLED
flag is not needed anymore.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

set_irq_chipdata -> set_irq_chip_data
get_irq_chipdata -> get_irq_chip_data
do_level_IRQ -> handle_level_irq
do_edge_IRQ -> handle_edge_irq
do_simple_IRQ -> handle_simple_irq
irqdesc -> irq_desc
irqchip -> irq_chip
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This should fix up the per-cpu irq register pointer if we have nested
hardware interrupts.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Untested, but this should fix up the bulk of the totally mechanical
issues, and should make the actual detail fixing easier.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Patch from David Brownell

ARM genirq cleanups/updates:

    - Start switching platforms to newer APIs
        * use "irq_chip" name, not "irqchip"
        * providing irq_chip.name

    - Show irq_chip.name in /proc/interrupts, like on x86.

This update a bit more than half of the ARM code.  The irq_chip.name
values were chosen to match docs (if I have them) or be otherwise
obvious ("FPGA", "CPLD", or matching the code).
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Thomas Gleixner

From: Thomas Gleixner <tglx@linutronix.de>

The genirq conversion of ARM lost a CPU Hotplug helper function.
Restore it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Thomas Gleixner

From: Thomas Gleixner <tglx@linutronix.de>

Switch the ARM irq core handling to the generic implementation. The
ARM specific header files now contain mostly migration stubs and
helper macros. Note that each machine type must be converted after
this step seperately. This was seperated out from the patch for easier
review.

The main changes for the machine type code is the conversion of the
type handlers to a 'type flow' and 'chip' model. This affects only the
multiplex interrupt handlers. A conversion macro needs to be added to
those implementations, which defines the data structure which is
registered by the set_irq_chained_handler() macro.

Some minor fixups of include files and the conversion of data
structure access is necessary all over the place.

The mostly macro based conversion was provided to allow an easy
migration of the existing implementations.

The code compiles on all defconfigs available in arch/arm/configs
except those which were broken also before applying the conversion
patches.

The code has been boot and runtime tested on most ARM platforms. The
results of an extensive testing and bugfixing series can be found
at: http://www.linutronix.de/index.php?page=testingSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>