linux/arch/ia64
Huang Ying df013ffb81 Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG
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: Huang Ying <ying.huang@intel.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Richard Henderson <rth@twiddle.net>
CC: Mikael Starvik <starvik@axis.com>
Acked-by: David 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: Ralf 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: Len Brown <len.brown@intel.com>
2011-08-03 11:12:37 -04:00
..
configs [IA64] Add CONFIG_MISC_DEVICES=y to configs that need it. 2011-03-02 13:35:22 -08:00
dig x86, ia64: convert to use generic dma_map_ops struct 2009-01-06 14:06:57 +01:00
hp Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2011-05-23 09:12:26 -07:00
include/asm [IA64] wire up sendmmsg() syscall for Itanium 2011-05-31 10:09:24 -07:00
kernel [IA64] wire up sendmmsg() syscall for Itanium 2011-05-31 10:09:24 -07:00
kvm KVM: ia64: fix sparse warnings 2011-05-22 08:39:57 -04:00
lib Fix common misspellings 2011-03-31 11:26:23 -03:00
mm mm: now that all old mmu_gather code is gone, remove the storage 2011-05-25 08:39:16 -07:00
oprofile [IA64] fix build warning in arch/ia64/oprofile/backtrace.c 2011-04-07 11:05:56 -07:00
pci ACPI: pci_root: pass acpi_pci_root to arch-specific scan 2010-04-04 00:29:53 -04:00
scripts scripts: change scripts to use system python instead of env 2010-02-02 14:33:56 +01:00
sn Merge branch 'consolidate-clksrc-i8253' of master.kernel.org:~rmk/linux-2.6-arm into timers/clocksource 2011-05-14 12:06:36 +02:00
uv ia64: change to new flag variables 2011-03-17 14:02:56 +01:00
xen sched: Provide scheduler_ipi() callback in response to smp_send_reschedule() 2011-04-14 08:52:32 +02:00
install.sh kbuild: use INSTALLKERNEL to select customized installkernel script 2009-09-20 12:18:14 +02:00
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00
Kconfig.debug
Makefile Merge commit 'v2.6.35' into kbuild/kbuild 2010-08-04 13:59:13 +02:00
module.lds