linux-toradex.git/arch/arm/kernel/irq.c, branch v3.2.20

ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQs

2012-05-11T12:14:46+00:00

commit 5e7371ded05adfcfcee44a8bc070bfc37979b8f2 upstream.

When a CPU is hotplugged off, we migrate any IRQs currently affine to it
away and onto another online CPU by calling the irq_set_affinity
function of the relevant interrupt controller chip. This function
returns either IRQ_SET_MASK_OK or IRQ_SET_MASK_OK_NOCOPY, to indicate
whether irq_data.affinity was updated.

If we are forcefully migrating an interrupt (because the affinity mask
no longer identifies any online CPUs) then we should update the IRQ
affinity mask to reflect the new CPU set. Failure to do so can
potentially leave /proc/irq/n/smp_affinity identifying only offline
CPUs, which may confuse userspace IRQ balancing daemons.

This patch updates migrate_one_irq to copy the affinity mask when
the interrupt chip returns IRQ_SET_MASK_OK after forcefully changing the
affinity of an interrupt.

Reported-by: Leif Lindholm 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Ben Hutchings

arm: remove several unnecessary module.h include instances

2011-10-31T23:30:48+00:00

Building these files does not reveal a hidden need for
any of these.  Since module.h brings in the whole kitchen
sink, it just needlessly adds 30k+ lines to the cpp burden.

There are probably lots more, but ARM files of mach-* and plat-*
don't get coverage via a simple yesconfig build.  They will have
to be cleaned up and tested via using their respective configs.

Signed-off-by: Paul Gortmaker

ARM: gic: consolidate PPI handling

2011-10-23T12:32:29+00:00

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 
Cc: David Brown 
Cc: Bryan Huntsman 
Cc: Tony Lindgren 
Cc: Paul Mundt 
Cc: Magnus Damm 
Cc: Thomas Gleixner 
Acked-by: David Brown 
Tested-by: David Brown 
Tested-by: Shawn Guo 
Signed-off-by: Marc Zyngier

ARM: 7115/4: move __exception and friends to asm/exception.h

2011-10-17T08:02:44+00:00

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 
Signed-off-by: Jamie Iles 
Signed-off-by: Russell King

Merge branch 'next/devel' of ssh://master.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc

2011-07-27T00:41:04+00:00

* 'next/devel' of ssh://master.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc: (128 commits)
  ARM: S5P64X0: External Interrupt Support
  ARM: EXYNOS4: Enable MFC on Samsung NURI
  ARM: EXYNOS4: Enable MFC on universal_c210
  ARM: S5PV210: Enable MFC on Goni
  ARM: S5P: Add support for MFC device
  ARM: EXYNOS4: Add support FIMD on SMDKC210
  ARM: EXYNOS4: Add platform device and helper functions for FIMD
  ARM: EXYNOS4: Add resource definition for FIMD
  ARM: EXYNOS4: Change devname for FIMD clkdev
  ARM: SAMSUNG: Add IRQ_I2S0 definition
  ARM: SAMSUNG: Add platform device for idma
  ARM: EXYNOS4: Add more registers to be saved and restored for PM
  ARM: EXYNOS4: Add more register addresses of CMU
  ARM: EXYNOS4: Add platform device for dwmci driver
  ARM: EXYNOS4: configure rtc-s3c on NURI
  ARM: EXYNOS4: configure MAX8903 secondary charger on NURI
  ARM: EXYNOS4: configure ADC on NURI
  ARM: EXYNOS4: configure MAX17042 fuel gauge on NURI
  ARM: EXYNOS4: configure regulators and PMIC(MAX8997) on NURI
  ARM: EXYNOS4: Increase NR_IRQS for devices with more IRQs
  ...

Fix up tons of silly conflicts:
 - arch/arm/mach-davinci/include/mach/psc.h
 - arch/arm/mach-exynos4/Kconfig
 - arch/arm/mach-exynos4/mach-smdkc210.c
 - arch/arm/mach-exynos4/pm.c
 - arch/arm/mach-imx/mm-imx1.c
 - arch/arm/mach-imx/mm-imx21.c
 - arch/arm/mach-imx/mm-imx25.c
 - arch/arm/mach-imx/mm-imx27.c
 - arch/arm/mach-imx/mm-imx31.c
 - arch/arm/mach-imx/mm-imx35.c
 - arch/arm/mach-mx5/mm.c
 - arch/arm/mach-s5pv210/mach-goni.c
 - arch/arm/mm/Kconfig

ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU

2011-07-21T14:14:21+00:00

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: Russell King

ARM: CPU hotplug: pass in proper affinity mask on IRQ migration

2011-07-21T14:07:56+00:00

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: Russell King

ARM: CPU hotplug: fix abuse of irqdesc->node

2011-07-21T14:00:27+00:00

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: Russell King

ARM: introduce handle_IRQ() not to dump exception stack

2011-07-12T11:42:40+00:00

On Mon, Jul 11, 2011 at 3:52 PM, Russell King - ARM Linux
 wrote:

...

> The __exception annotation on a function causes this to happen:
>
> [] (asm_do_IRQ+0x6c/0x8c) from []
> (__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: Russell King 
Signed-off-by: Eric Miao

arm: Use generic show_interrupts()

2011-03-29T12:47:57+00:00

Use the generic version and just keep the arch specific output.

Signed-off-by: Thomas Gleixner