Commit f27d6e17 authored May 16, 2013 by Will Deacon Committed by Russell King May 22, 2013

ARM: 7729/1: vfp: ensure VFP_arch is non-zero when VFP is not supported



Commit d3f79584 ("ARM: cleanup undefined instruction entry code")
improved the register scheduling when handling undefined instructions.
A side effect of this is that r5 is now used as a temporary, whilst the
VFP probing code relies on r5 containing a non-zero value when VFP is
not supported.

This patch fixes the VFP detection code so that we don't rely on the
contents of r5. Without this patch, Linux dies loudly on CPUs without
VFP support.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 4ca46c5e

arch/arm/vfp/entry.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -60,7 +60,7 @@ ENTRY(vfp_testing_entry)
		str r11, [r10, #TI_PREEMPT]
		#endif
		ldr r0, VFP_arch_address
		str r5, [r0] @ known non-zero value
		str r0, [r0] @ set to non-zero value
		mov pc, r9 @ we have handled the fault
		ENDPROC(vfp_testing_entry)