linux/arch/alpha
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
..
boot include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
include/asm Fix node_start/end_pfn() definition for mm/page_cgroup.c 2011-06-27 14:13:09 -07:00
kernel alpha: fix several security issues 2011-06-15 20:04:02 -07:00
lib Fix common misspellings 2011-03-31 11:26:23 -03:00
math-emu alpha: change to new Makefile flag variables 2011-01-17 05:42:13 +01:00
mm alpha, mm: set all online nodes in N_NORMAL_MEMORY 2011-05-25 08:39:23 -07:00
oprofile Fix common misspellings 2011-03-31 11:26:23 -03:00
defconfig defconfig reduction 2010-08-14 22:26:53 +02:00
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00
Kconfig.debug
Makefile