linux/arch/x86
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 x86, setup: When probing memory with e801, use ax/bx as a pair 2011-04-25 14:52:37 -07:00
configs cgroup: remove the ns_cgroup 2011-05-26 17:12:34 -07:00
crypto crypto: aesni-intel - fix aesni build on i386 2011-05-18 09:03:34 +10:00
ia32 ns: Wire up the setns system call 2011-05-28 10:48:39 -07:00
include/asm x86-32, NUMA: Fix boot regression caused by NUMA init unification on highmem machines 2011-07-01 13:38:51 +02:00
kernel x86, suspend: Restore MISC_ENABLE MSR in realmode wakeup 2011-07-06 20:09:34 -07:00
kvm KVM: x86 emulator: fix %rip-relative addressing with immediate source operand 2011-06-29 10:09:25 +03:00
lguest lguest: fix timer interrupt setup 2011-05-30 11:14:10 +09:30
lib Merge branches 'x86-apic-for-linus', 'x86-asm-for-linus' and 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-19 17:49:35 -07:00
math-emu
mm mm: Move definition of MIN_MEMORY_BLOCK_SIZE to a header 2011-07-12 11:08:01 +10:00
net net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
oprofile oprofile, x86: Fix race in nmi handler while starting counters 2011-06-15 14:31:29 +02:00
pci Merge branch 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen 2011-07-07 13:19:04 -07:00
platform x86: Don't use the EFI reboot method by default 2011-07-07 11:35:05 +02:00
power x86, tsc, sched: Recompute cyc2ns_offset's during resume from sleep states 2010-08-20 14:59:02 +02:00
tools
vdso x86: vdso: Remove unused variable 2011-05-26 13:17:35 +02:00
video
xen xen/mmu: Fix for linker errors when CONFIG_SMP is not defined. 2011-06-30 09:21:10 -04:00
.gitignore
Kbuild net: filter: Just In Time compiler for x86-64 2011-04-27 23:05:08 -07:00
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00
Kconfig.cpu x86, cpu: Move AMD Elan Kconfig under "Processor family" 2011-04-08 13:01:25 -07:00
Kconfig.debug lib: consolidate DEBUG_STACK_USAGE option 2011-05-25 08:39:54 -07:00
Makefile Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 13:06:00 -07:00
Makefile_32.cpu x86, cpu: Move AMD Elan Kconfig under "Processor family" 2011-04-08 13:01:25 -07:00