On Fri, Oct 31, 2014 at 01:42:44PM +0800, Wang, Yalin wrote: > This patch add bitrev.h file to support rbit instruction, > so that we can do bitrev operation by hardware. > Signed-off-by: Yalin Wang <yalin.wang@xxxxxxxxxxxxxx> > --- > arch/arm/Kconfig | 1 + > arch/arm/include/asm/bitrev.h | 21 +++++++++++++++++++++ > 2 files changed, 22 insertions(+) > create mode 100644 arch/arm/include/asm/bitrev.h > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 89c4b5c..be92b3b 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -28,6 +28,7 @@ config ARM > select HANDLE_DOMAIN_IRQ > select HARDIRQS_SW_RESEND > select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT) > + select HAVE_ARCH_BITREVERSE if (CPU_V7M || CPU_V7) Looking at this, this is just wrong. Take a moment to consider what happens if we build a kernel which supports both ARMv6 _and_ ARMv7 CPUs. What happens if an ARMv6 CPU tries to execute an rbit instruction? Second point (which isn't obvious from your submissions on-list) is that you've loaded the patch system up with patches for other parts of the kernel tree for which I am not responsible for. As such, I can't take those patches without the sub-tree maintainer acking them. Also, the commit text in those patches look weird: 6fire: Convert byte_rev_table uses to bitrev8 Use the inline function instead of directly indexing the array. This allows some architectures with hardware instructions for bit reversals to eliminate the array. Signed-off-by: Joe Perches <(address hidden)> Signed-off-by: Yalin Wang <(address hidden)> Why is Joe signing off on these patches? As his is the first sign-off, one assumes that he was responsible for creating the patch in the first place, but there is no From: line marking him as the author. Shouldn't his entry be an Acked-by: ? Confused. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>