ARM: 7893/1: bitops: only emit .arch_extension mp if CONFIG_SMP
authorWill Deacon <will.deacon@arm.com>
Tue, 19 Nov 2013 14:46:11 +0000 (15:46 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Wed, 20 Nov 2013 23:05:53 +0000 (23:05 +0000)
Uwe reported a build failure when targetting a NOMMU platform with my
recent prefetch changes:

  arch/arm/lib/changebit.S: Assembler messages:
  arch/arm/lib/changebit.S:15: Error: architectural extension `mp' is
not allowed for the current base architecture

This is due to use of the .arch_extension mp directive immediately prior
to an ALT_SMP(...) instruction. Whilst the ALT_SMP macro will expand to
nothing if !CONFIG_SMP, gas will still choke on the directive.

This patch fixes the issue by only emitting the sequence (including the
directive) if CONFIG_SMP=y.

Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/lib/bitops.h

index e0c68d5..52886b8 100644 (file)
@@ -10,7 +10,7 @@ UNWIND(       .fnstart        )
        and     r3, r0, #31             @ Get bit offset
        mov     r0, r0, lsr #5
        add     r1, r1, r0, lsl #2      @ Get word offset
-#if __LINUX_ARM_ARCH__ >= 7
+#if __LINUX_ARM_ARCH__ >= 7 && defined(CONFIG_SMP)
        .arch_extension mp
        ALT_SMP(W(pldw) [r1])
        ALT_UP(W(nop))