DYNAMIC_MEMSTART(old RELOCATABLE) was restricted only to PPC_47x variants
of 44x. This patch enables DYNAMIC_MEMSTART for 440x based chipsets.
Signed-off-by: NSuzuki K. Poulose <suzuki@in.ibm.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux ppc dev <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: NJosh Boyer <jwboyer@gmail.com>

The current implementation of CONFIG_RELOCATABLE in BookE is based
on mapping the page aligned kernel load address to KERNELBASE. This
approach however is not enough for platforms, where the TLB page size
is large (e.g, 256M on 44x). So we are renaming the RELOCATABLE used
currently in BookE to DYNAMIC_MEMSTART to reflect the actual method.

The CONFIG_RELOCATABLE for PPC32(BookE) based on processing of the
dynamic relocations will be introduced in the later in the patch series.

This change would allow the use of the old method of RELOCATABLE for
platforms which can afford to enforce the page alignment (platforms with
smaller TLB size).

Changes since v3:

* Introduced a new config, NONSTATIC_KERNEL, to denote a kernel which is
  either a RELOCATABLE or DYNAMIC_MEMSTART(Suggested by: Josh Boyer)
Suggested-by: NScott Wood <scottwood@freescale.com>
Tested-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NSuzuki K. Poulose <suzuki@in.ibm.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linux ppc dev <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: NJosh Boyer <jwboyer@gmail.com>

This patch provides cpu_idle_wait() routine for the powerpc
platform which is required by the cpuidle subsystem. This
routine is required to change the idle handler on SMP systems.
The equivalent routine for x86 is in arch/x86/kernel/process.c
but the powerpc implementation is different.

cpuidle_disable variable is to enable/disable cpuidle
framework if power_save option is set during the boot
time.
Signed-off-by: NDeepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: NTrinabh Gupta <g.trinabh@gmail.com>
Signed-off-by: NArun R Bharadwaj <arun.r.bharadwaj@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

All interrupts which must be non threaded are marked
IRQF_NO_THREAD. So it's safe to allow force threaded handlers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Kexec is not supported on 47x. 47x is a variant of 44x with slightly
different MMU and SMP support. There was a typo in the config dependency
for kexec. This patch fixes the same.
Signed-off-by: NSuzuki K. Poulose <suzuki@in.ibm.com>
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Cc:	Kumar Gala <galak@kernel.crashing.org>
Cc:	Josh Boyer <jwboyer@gmail.com>
Cc:	linux ppc dev <linuxppc-dev@lists.ozlabs.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Unplugged CPU go into NAP mode in a loop until woken up
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Enable hugepages on Freescale BookE processors.  This allows the kernel to
use huge TLB entries to map pages, which can greatly reduce the number of
TLB misses and the amount of TLB thrashing experienced by applications with
large memory footprints.  Care should be taken when using this on FSL
processors, as the number of large TLB entries supported by the core is low
(16-64) on current processors.

The supported set of hugepage sizes include 4m, 16m, 64m, 256m, and 1g.
Page sizes larger than the max zone size are called "gigantic" pages and
must be allocated on the command line (and cannot be deallocated).

This is currently only fully implemented for Freescale 32-bit BookE
processors, but there is some infrastructure in the code for
64-bit BooKE.
Signed-off-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Allow the p1010 processor to select the flexcan network driver.
Signed-off-by: NRobin Holt <holt@sgi.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>,
Acked-by: Wolfgang Grandegger <wg@grandegger.com>,
Cc: U Bhaskar-B22300 <B22300@freescale.com>
Cc: socketcan-core@lists.berlios.de,
Cc: netdev@vger.kernel.org,
Cc: PPC list <linuxppc-dev@lists.ozlabs.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds kexec support for PPC440 based chipsets.  This work is based
on the KEXEC patches for FSL BookE.

The FSL BookE patch and the code flow could be found at the link below:

	http://patchwork.ozlabs.org/patch/49359/

Steps:

1) Invalidate all the TLB entries except the one this code is run from
2) Create a tmp mapping for our code in the other address space and jump to it
3) Invalidate the entry we used
4) Create a 1:1 mapping for 0-2GiB in blocks of 256M
5) Jump to the new 1:1 mapping and invalidate the tmp mapping

I have tested this patches on Ebony, Sequoia boards and Virtex on QEMU.

You need kexec-tools commit e8b7939b1e or newer for ppc440x support, 
available at:

 git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.gitSigned-off-by: NSuzuki Poulose <suzuki@in.ibm.com>
Cc:	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NJosh Boyer <jwboyer@gmail.com>

cmpxchg() is widely used by lockless code, including NMI-safe lockless
code.  But on some architectures, the cmpxchg() implementation is not
NMI-safe, on these architectures the lockless code may need a
spin_trylock_irqsave() based implementation.

This patch adds a Kconfig option: ARCH_HAVE_NMI_SAFE_CMPXCHG, so that
NMI-safe lockless code can depend on it or provide different
implementation according to it.

On many architectures, cmpxchg is only NMI-safe for several specific
operand sizes. So, ARCH_HAVE_NMI_SAFE_CMPXCHG define in this patch
only guarantees cmpxchg is NMI-safe for sizeof(unsigned long).
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NRichard Henderson <rth@twiddle.net>
CC: Mikael Starvik <starvik@axis.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
CC: Yoshinori Sato <ysato@users.sourceforge.jp>
CC: Tony Luck <tony.luck@intel.com>
CC: Hirokazu Takata <takata@linux-m32r.org>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Michal Simek <monstr@monstr.eu>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
CC: Kyle McMartin <kyle@mcmartin.ca>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Chen Liqin <liqin.chen@sunplusct.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ingo Molnar <mingo@redhat.com>
CC: Chris Zankel <chris@zankel.net>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

An implementation of a code generator for BPF programs to speed up packet
filtering on PPC64, inspired by Eric Dumazet's x86-64 version.

Filter code is generated as an ABI-compliant function in module_alloc()'d mem
with stackframe & prologue/epilogue generated if required (simple filters don't
need anything more than an li/blr).  The filter's local variables, M[], live in
registers.  Supports all BPF opcodes, although "complicated" loads from negative
packet offsets (e.g. SKF_LL_OFF) are not yet supported.

There are a couple of further optimisations left for future work; many-pass
assembly with branch-reach reduction and a register allocator to push M[]
variables into volatile registers would improve the code quality further.

This currently supports big-endian 64-bit PowerPC only (but is fairly simple
to port to PPC32 or LE!).

Enabled in the same way as x86-64:

	echo 1 > /proc/sys/net/core/bpf_jit_enable

Or, enabled with extra debug output:

	echo 2 > /proc/sys/net/core/bpf_jit_enable
Signed-off-by: NMatt Evans <matt@ozlabs.org>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 44x code (which is shared by 47x) assumes the available physical memory
begins at 0x00000000.  This is not necessarily the case in an AMP
environment.

Support CONFIG_RELOCATABLE for 476 in order to allow the kernel to be
loaded into a higher memory range.
Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

This patch adds support for the new "jump label" feature.

Unlike x86 and sparc we just merrily patch the code with no locks etc,
as far as I know this is safe, but I'm not really sure what the x86/sparc
code is protecting against so maybe it's not.

I also don't see any reason for us to implement the poke_early() routine,
even though sparc does.

[BenH: Updated the patch to upstream generic changes]
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

By the previous style change, CONFIG_GENERIC_FIND_NEXT_BIT,
CONFIG_GENERIC_FIND_BIT_LE, and CONFIG_GENERIC_FIND_LAST_BIT are not used
to test for existence of find bitops anymore.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NGreg Ungerer <gerg@uclinux.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements the raw syscall tracepoints on PowerPC and exports
them for ftrace syscalls to use.

To minimise reworking existing code, I slightly re-ordered the thread
info flags such that the new TIF_SYSCALL_TRACEPOINT bit would still fit
within the 16 bits of the andi. instruction's UI field. The instructions
in question are in /arch/powerpc/kernel/entry_{32,64}.S to and the
_TIF_SYSCALL_T_OR_A with the thread flags to see if system call tracing
is enabled.

In the case of 64bit PowerPC, arch_syscall_addr and
arch_syscall_match_sym_name are overridden to allow ftrace syscalls to
work given the unusual system call table structure and symbol names that
start with a period.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In case other architectures require RCU freed page-tables to implement
gup_fast() and software filled hashes and similar things, provide the
means to do so by moving the logic into generic code.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Requested-by: NDavid Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a first cut at making bootwrapper code which will
produce a zImage compliant with the requirements set down
by ePAPR.

This is a very simple bootwrapper, taking the device tree
blob supplied by the ePAPR boot program and passing it on
to the kernel. It builds on the earlier patch to build a
relocatable ET_DYN zImage to meet the other ePAPR image
requirements.

For good measure we have some paranoid checks which will
generate warnings if some of the ePAPR entry condition
guarantees are not met.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We currently dont have CPU Hotplug support working on 85xx so we need to
disable Suspsend support as it will force enabling of CPU Hotplug.

arch/powerpc/kernel/built-in.o: In function `cpu_die': arch/powerpc/kernel/smp.c:702: undefined reference to `start_secondary_resume'
make: *** [.tmp_vmlinux1] Error 1
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

1. Add an option to include RapidIO support if the PCI is available.
2. Add FSL_RIO configuration option to enable controller selection.
3. Add RapidIO support option into x86 and MIPS architectures.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Micha Nelissen <micha@neli.hopto.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This introduces CONFIG_GENERIC_FIND_BIT_LE to tell whether to use generic
implementation of find_*_bit_le() in lib/find_next_bit.c or not.

For now we select CONFIG_GENERIC_FIND_BIT_LE for all architectures which
enable CONFIG_GENERIC_FIND_NEXT_BIT.

But m68knommu wants to define own faster find_next_zero_bit_le() and
continues using generic find_next_{,zero_}bit().
(CONFIG_GENERIC_FIND_NEXT_BIT and !CONFIG_GENERIC_FIND_BIT_LE)
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NLennert Buytenhek <buytenh@secretlab.ca>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

No functional change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>

All architectures are finally converted. Remove the cruft.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>

The device tree code is now in two pieces: some which can be used generically
on any platform which selects CONFIG_OF_FLATTREE, and some early which is used
at boot time on only a few architectures.  This patch segregates the early
code so that only those architectures which care about it need compile it.
This also means that some of the requirements in the early code (such as
a cmd_line variable) that most architectures (e.g. X86) don't provide
can be ignored.
Signed-off-by: NStephen Neuendorffer <stephen.neuendorffer@xilinx.com>
[grant.likely@secretlab.ca: remove extra blank line addition]
[grant.likely@secretlab.ca: fixed incorrect #ifdef CONFIG_EARLY_FLATTREE check]
[grant.likely@secretlab.ca: Made OF_EARLY_FLATTREE select instead of depend
                            on OF_FLATTREE]
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Add suspend/resume support for 4xx compatible CPUs.
See /sys/power/state for available power states configured in.

Add two different idle states (idle-wait and idle-doze) controlled via sysfs.
Default is idle-wait.
	cat /sys/devices/system/cpu/cpu0/idle
	[wait] doze

To save additional power, use idle-doze.
	echo doze > /sys/devices/system/cpu/cpu0/idle
	cat /sys/devices/system/cpu/cpu0/idle
	wait [doze]
Signed-off-by: NVictor Gallardo <vgallardo@apm.com>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

commit ffe8018c of the -mm tree
fixes the initramfs size calculation for e.g. s390 but breaks it
for 32bit architectures which do not define CONFIG_32BIT.

This patch fix the problem for PPC32 which will elsewise end up
with a __initramfs_size of 0.
Signed-off-by: NKerstin Jonsson <kerstin.jonsson@ericsson.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Move Freescale elbc interrupt from nand driver to elbc driver.
Then all elbc devices can use the interrupt instead of ONLY nand.

For former nand driver, it had the two functions:

1. detecting nand flash partitions;
2. registering elbc interrupt.

Now, second function is removed to fsl_lbc.c.
Signed-off-by: NLan Chunhe-B25806 <b25806@freescale.com>
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Reviewed-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Cc: Wood Scott-B07421 <B07421@freescale.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.

Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.

The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.

Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
[ various fixes ]
Signed-off-by: NHuang Ying <ying.huang@intel.com>
LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NArnaud Lacombe <lacombar@gmail.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Reviewed-by: NMichal Marek <mmarek@suse.cz>

Adds support for kexec on 85xx machines for the BookE platform.
Including support for SMP machines

Based off work from Maxim Uvarov <muvarov@mvista.com>
Signed-off-by: NMatthew McClintock <msm@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

On PowerPC we should always use generic ISA DMA API implementation
as there is simply no other implementation exist.

Without this patch, the following build error pops up:

  sound/built-in.o: In function 'snd_dma_pointer':
  (.text+0x74ae): undefined reference to 'dma_spin_lock'
  ...
  make: *** [.tmp_vmlinux1] Error 1

This is PPC_85xx, SMP and some sound drivers set to =y.
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Acked-by: NDave Liu <daveliu@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

via following scripts

      FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

      sed -i \
        -e 's/lmb/memblock/g' \
        -e 's/LMB/MEMBLOCK/g' \
        $FILES

      for N in $(find . -name lmb.[ch]); do
        M=$(echo $N | sed 's/lmb/memblock/g')
        mv $N $M
      done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/
Suggested-by: NIngo Molnar <mingo@elte.hu>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Enables support for HMC initiated partition hibernation. This is
a firmware assisted hibernation, since the firmware handles writing
the memory out to disk, along with other partition information,
so we just mimic suspend to ram.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The SPARSE_IRQ considerably adds overhead to critical path of IRQ
handling.  However it doesn't benefit much in space for most systems with
limited IRQ_NR.  Should be disabled unless really necessary.
Signed-off-by: NLi Yang <leoli@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>