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authorHuang Ying <ying.huang@intel.com>2011-07-13 13:14:22 +0800
committerLen Brown <len.brown@intel.com>2011-08-03 11:12:37 -0400
commitdf013ffb8119c89f062ab05b7f544704315db47b (patch)
treedb87f30545d2fd6cf9b0a547f09d924df3be90dd /arch/tile/Kconfig
parent9fb0bfe1408d5506b7b83d13d1eed573fd71d67d (diff)
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>
Diffstat (limited to 'arch/tile/Kconfig')
-rw-r--r--arch/tile/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 0249b8b4db5..b30f71ac0d0 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -12,6 +12,7 @@ config TILE
select GENERIC_PENDING_IRQ if SMP
select GENERIC_IRQ_SHOW
select SYS_HYPERVISOR
+ select ARCH_HAVE_NMI_SAFE_CMPXCHG if !M386
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT