linux/arch/frv
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 FRV: Drop 'TOPDIR' from Makefiles 2008-01-28 23:14:37 +01:00
include/asm Merge branch 'setns' 2011-05-28 10:51:01 -07:00
kernel ns: Wire up the setns system call 2011-05-28 10:48:39 -07:00
lib irq_work: Add generic hardirq context callbacks 2010-10-18 19:58:50 +02:00
mb93090-mb00 mm: stack based kmap_atomic() 2010-10-26 16:52:08 -07:00
mm mm: now that all old mmu_gather code is gone, remove the storage 2011-05-25 08:39:16 -07:00
defconfig kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00
Kconfig.debug [PATCH] frv: drop unsupported debugging features 2006-01-08 20:13:36 -08:00
Makefile frv: clean up arch/frv/Makefile 2010-08-03 14:09:45 +02:00