From: Stepan Moskovchenko <stepanm@codeaurora.org>
Date: Mon, 10 Nov 2014 20:56:42 +0000 (+0100)
Subject: ARM: 8195/1: vfp: Bounce undefined instructions in vectored mode
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=1ca8bf6f7ba581d8b47144ff5a558e17fba3190d;p=deliverable%2Flinux.git

ARM: 8195/1: vfp: Bounce undefined instructions in vectored mode

Certain ARM CPU implementations (e.g. Cortex-A15) may not raise a
floating- point exception whenever deprecated short-vector VFP
instructions are executed. Instead these instructions are treated
as UNALLOCATED. Change the VFP exception handling code to emulate
short-vector instructions even if FPEXC exception bits are not
set.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index cda654cbf2c2..f74a8f7e5f84 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -197,6 +197,12 @@ look_for_VFP_exceptions:
 	tst	r5, #FPSCR_IXE
 	bne	process_exception
 
+	tst	r5, #FPSCR_LENGTH_MASK
+	beq	skip
+	orr	r1, r1, #FPEXC_DEX
+	b	process_exception
+skip:
+
 	@ Fall into hand on to next handler - appropriate coproc instr
 	@ not recognised by VFP