Support sparcv9 32-bit build

Support sparcv9 32-bit build

From: David Miller <davem@davemloft.net>
Subject: Re: [ltt-dev] Sparc64 support added to Userspace RCU

From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Thu, 22 Oct 2009 15:57:53 -0400

> Feedback is welcome,

__sparc_v8__ does not mean 64-bit longs or pointers as implied here:

"v8" was the last 32-bit standard of the cpu architecture.

Otherwise looks fine.

Although this port won't be very useful until it can be built in
32-bit mode.  As most applications on sparc64 systems are still
32-bit.  Like on powerpc, people only rarely build things 64-bit on
sparc64.

You need to build with "-Wa,-Av9a" on the GCC command line for that
case so that the assembler allows the v9 instructions emitted by your
macros, even when building for 32-bit.

Hope this helps.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: David Miller <davem@davemloft.net>