From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Thu, 18 Sep 2014 14:43:12 -0700 Subject: [PATCH 3/3] arm: vfp: Bounce undefined instructions in vectored mode In-Reply-To: <1411076592-6157-1-git-send-email-sboyd@codeaurora.org> References: <1411076592-6157-1-git-send-email-sboyd@codeaurora.org> Message-ID: <1411076592-6157-4-git-send-email-sboyd@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Stepan Moskovchenko 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. Tested-by: Will Deacon Signed-off-by: Stepan Moskovchenko Signed-off-by: Stephen Boyd --- arch/arm/vfp/vfphw.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S index be807625ed8c..c041579a8d82 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 -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation