diff options
| author | Huang Ying <ying.huang@intel.com> | 2011-07-13 13:14:22 +0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2011-08-03 11:12:37 -0400 |
| commit | df013ffb8119c89f062ab05b7f544704315db47b (patch) | |
| tree | db87f30545d2fd6cf9b0a547f09d924df3be90dd /arch/avr32 | |
| parent | 9fb0bfe1408d5506b7b83d13d1eed573fd71d67d (diff) | |
| download | linux-df013ffb8119c89f062ab05b7f544704315db47b.tar.gz | |
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/avr32')
| -rw-r--r-- | arch/avr32/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig index e9d689b7c833..197e96f70405 100644 --- a/arch/avr32/Kconfig +++ b/arch/avr32/Kconfig @@ -10,6 +10,7 @@ config AVR32 select GENERIC_IRQ_PROBE select HARDIRQS_SW_RESEND select GENERIC_IRQ_SHOW + select ARCH_HAVE_NMI_SAFE_CMPXCHG help AVR32 is a high-performance 32-bit RISC microprocessor core, designed for cost-sensitive embedded applications, with particular |