From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49679) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcwlF-0003fc-5L for qemu-devel@nongnu.org; Wed, 02 Aug 2017 12:44:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcwlE-0004t5-DC for qemu-devel@nongnu.org; Wed, 02 Aug 2017 12:44:41 -0400 From: Peter Maydell Date: Wed, 2 Aug 2017 17:43:48 +0100 Message-Id: <1501692241-23310-3-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1501692241-23310-1-git-send-email-peter.maydell@linaro.org> References: <1501692241-23310-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH 02/15] target/arm: Don't trap WFI/WFE for M profile List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-arm@nongnu.org, qemu-devel@nongnu.org Cc: patches@linaro.org M profile cores can never trap on WFI or WFE instructions. Check for M profile in check_wfx_trap() to ensure this. The existing code will do the right thing for v7M cores because the hcr_el2 and scr_el3 registers will be all-zeroes and so we won't attempt to trap, but when we start setting ARM_FEATURE_V8 for v8M cores the v8A handling of SCTLR.nTWE and .nTWI will not give the right results. Signed-off-by: Peter Maydell --- target/arm/op_helper.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c index 2a85666..5a94a5f 100644 --- a/target/arm/op_helper.c +++ b/target/arm/op_helper.c @@ -370,6 +370,11 @@ static inline int check_wfx_trap(CPUARMState *env, bool is_wfe) int cur_el = arm_current_el(env); uint64_t mask; + if (arm_feature(env, ARM_FEATURE_M)) { + /* M profile cores can never trap WFI/WFE. */ + return 0; + } + /* If we are currently in EL0 then we need to check if SCTLR is set up for * WFx instructions being trapped to EL1. These trap bits don't exist in v7. */ -- 2.7.4