From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Wed, 27 Mar 2013 17:11:52 +0000 Subject: [PATCH 5/5] ARM: arch_timer: stop virtual timer when booted in HYP mode In-Reply-To: <1364404312-4427-1-git-send-email-mark.rutland@arm.com> References: <1364404312-4427-1-git-send-email-mark.rutland@arm.com> Message-ID: <1364404312-4427-6-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Marc Zyngier When booting the kernel, a bootloader could have left the virtual timer ticking away, potentially generating interrupts. This could be troublesome if the user of the virtual timer is not careful when enabling the interrupt. In order to avoid any surprise, stop the virtual timer from interrupting us when booted in HYP mode, as we'll use the physical timer in this case. Reported-by: Giridhar Maruthy Signed-off-by: Marc Zyngier Signed-off-by: Mark Rutland Cc: Dave Martin --- arch/arm/kernel/hyp-stub.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index dbe2110..4910232 100644 --- a/arch/arm/kernel/hyp-stub.S +++ b/arch/arm/kernel/hyp-stub.S @@ -155,6 +155,11 @@ THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL mov r7, #0 mcrr p15, 4, r7, r7, c14 @ CNTVOFF + + @ Disable virtual timer in case it was counting + mrc p15, 0, r7, c14, c3, 1 @ CNTV_CTL + bic r7, #1 @ Clear ENABLE + mcr p15, 0, r7, c14, c3, 1 @ CNTV_CTL 1: #endif -- 1.8.1.1