From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Fri, 13 Nov 2015 10:48:07 -0800 Subject: [PATCH] ARM: PJ4: move coprocessor register access sequences to iwmmxt.S In-Reply-To: <1447397933-13379-1-git-send-email-ard.biesheuvel@linaro.org> References: <1447397933-13379-1-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <20151113184807.GA21047@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 11/13, Ard Biesheuvel wrote: > The PJ4 inline asm sequences in pj4-cp0.c cannot be built in Thumb-2 mode, > due to the way it performs arithmetic on the program counter, so it is > built in ARM mode instead. However, building C files in ARM mode under > CONFIG_THUMB2_KERNEL is problematic, since the instrumentation performed > by subsystems like ftrace does not expect having to deal with interworking > branches. > > So instead, revert to building pj4-cp0.c in Thumb-2 mode, and move the > offending sequence to iwmmxt.S, which is not instrumented anyway, and is > already built in ARM mode unconditionally. > > Reported-by: Stephen Boyd > Signed-off-by: Ard Biesheuvel > --- Tested-by: Stephen Boyd -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project