From 0af0b189abf73d232af782df2f999235cd2fed7f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 30 Jan 2013 18:17:49 +0000 Subject: ARM: hyp: initialize CNTVOFF to zero In order to be able to use the virtual counter in a safe way, make sure it is initialized to zero before dropping to SVC. Signed-off-by: Marc Zyngier Signed-off-by: Mark Rutland Acked-by: Santosh Shilimkar Cc: Dave Martin --- arch/arm/kernel/hyp-stub.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch') diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index 1315c4ccfa56..dbe21107945a 100644 --- a/arch/arm/kernel/hyp-stub.S +++ b/arch/arm/kernel/hyp-stub.S @@ -153,6 +153,8 @@ THUMB( orr r7, #(1 << 30) ) @ HSCTLR.TE mrc p15, 4, r7, c14, c1, 0 @ CNTHCTL orr r7, r7, #3 @ PL1PCEN | PL1PCTEN mcr p15, 4, r7, c14, c1, 0 @ CNTHCTL + mov r7, #0 + mcrr p15, 4, r7, r7, c14 @ CNTVOFF 1: #endif -- cgit v1.2.1 From f793c23ebbe5afd1cabf4a42a3a297022213756f Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 26 Mar 2013 13:41:35 +0000 Subject: ARM: KVM: arch_timers: zero CNTVOFF upon return to host To use the virtual counters from the host, we need to ensure that CNTVOFF doesn't change unexpectedly. When we change to a guest, we replace the host's CNTVOFF, but we don't restore it when returning to the host. As the host sets CNTVOFF to zero, and never changes it, we can simply zero CNTVOFF when returning to the host. This patch adds said zeroing to the return to host path. Signed-off-by: Mark Rutland Acked-by: Marc Zyngier Acked-by: Santosh Shilimkar Acked-by: Christoffer Dall --- arch/arm/kvm/interrupts_head.S | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index 3c8f2f0b4c5e..d43cfb5b37c4 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S @@ -497,6 +497,10 @@ vcpu .req r0 @ vcpu pointer always in r0 add r5, vcpu, r4 strd r2, r3, [r5] + @ Ensure host CNTVCT == CNTPCT + mov r2, #0 + mcrr p15, 4, r2, r2, c14 @ CNTVOFF + 1: #endif @ Allow physical timer/counter access for the host -- cgit v1.2.1 From 0d651e4e65e96989f72236bf83bd4c6e55eb6ce4 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 30 Jan 2013 17:51:26 +0000 Subject: clocksource: arch_timer: use virtual counters Switching between reading the virtual or physical counters is problematic, as some core code wants a view of time before we're fully set up. Using a function pointer and switching the source after the first read can make time appear to go backwards, and having a check in the read function is an unfortunate block on what we want to be a fast path. Instead, this patch makes us always use the virtual counters. If we're a guest, or don't have hyp mode, we'll use the virtual timers, and as such don't care about CNTVOFF as long as it doesn't change in such a way as to make time appear to travel backwards. As the guest will use the virtual timers, a (potential) KVM host must use the physical timers (which can wake up the host even if they fire while a guest is executing), and hence a host must have CNTVOFF set to zero so as to have a consistent view of time between the physical timers and virtual counters. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Acked-by: Marc Zyngier Acked-by: Santosh Shilimkar Cc: Rob Herring --- arch/arm/include/asm/arch_timer.h | 9 --------- arch/arm64/include/asm/arch_timer.h | 10 ---------- 2 files changed, 19 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 7c1bfc0aea0c..accefe099182 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -80,15 +80,6 @@ static inline u32 arch_timer_get_cntfrq(void) return val; } -static inline u64 arch_counter_get_cntpct(void) -{ - u64 cval; - - isb(); - asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval)); - return cval; -} - static inline u64 arch_counter_get_cntvct(void) { u64 cval; diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index bf6ab242f047..d56ed11ba9a3 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -110,16 +110,6 @@ static inline void __cpuinit arch_counter_set_user_access(void) asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl)); } -static inline u64 arch_counter_get_cntpct(void) -{ - u64 cval; - - isb(); - asm volatile("mrs %0, cntpct_el0" : "=r" (cval)); - - return cval; -} - static inline u64 arch_counter_get_cntvct(void) { u64 cval; -- cgit v1.2.1 From fb521a0da1551468a45f2e2a1c1941d0033357ea Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 20 Mar 2013 13:57:38 +0000 Subject: arm: fix up ARM_ARCH_TIMER selects In 8a4da6e: "arm: arch_timer: move core to drivers/clocksource", the selection of ARM_ARCH_TIMER was indirected via HAVE_ARM_ARCH_TIMER, though mach-exynos's selection of ARM_ARCH_TIMER was missed, and since then mach-shmobile, mach-tegra, and mach-virt have begun selecting ARM_ARCH_TIMER. This can lead to architected timer support erroneously appearing to not be selected in menuconfig. This patch fixes up the Kconfigs for those platforms to select HAVE_ARM_ARCH_TIMER. Signed-off-by: Mark Rutland Acked-by: Stephen Warren Acked-by: Santosh Shilimkar Acked-by: Simon Horman Cc: Kukjin Kim Cc: Marc Zyngier --- arch/arm/mach-exynos/Kconfig | 2 +- arch/arm/mach-shmobile/Kconfig | 4 ++-- arch/arm/mach-tegra/Kconfig | 2 +- arch/arm/mach-virt/Kconfig | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) (limited to 'arch') diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig index d19edff0ea6e..3c3f36a8fbd4 100644 --- a/arch/arm/mach-exynos/Kconfig +++ b/arch/arm/mach-exynos/Kconfig @@ -76,7 +76,7 @@ config SOC_EXYNOS5440 default y depends on ARCH_EXYNOS5 select ARCH_HAS_OPP - select ARM_ARCH_TIMER + select HAVE_ARM_ARCH_TIMER select AUTO_ZRELADDR select PINCTRL select PINCTRL_EXYNOS5440 diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig index 1a517e2fe449..767a6c3c27a4 100644 --- a/arch/arm/mach-shmobile/Kconfig +++ b/arch/arm/mach-shmobile/Kconfig @@ -23,7 +23,7 @@ config ARCH_R8A73A4 select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_GIC select CPU_V7 - select ARM_ARCH_TIMER + select HAVE_ARM_ARCH_TIMER select SH_CLK_CPG select RENESAS_IRQC @@ -56,7 +56,7 @@ config ARCH_R8A7790 select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_GIC select CPU_V7 - select ARM_ARCH_TIMER + select HAVE_ARM_ARCH_TIMER select SH_CLK_CPG select RENESAS_IRQC diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index 84d72fc36dfe..65c5ae6fa386 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -60,7 +60,7 @@ config ARCH_TEGRA_3x_SOC config ARCH_TEGRA_114_SOC bool "Enable support for Tegra114 family" - select ARM_ARCH_TIMER + select HAVE_ARM_ARCH_TIMER select ARM_GIC select ARM_L1_CACHE_SHIFT_6 select CPU_FREQ_TABLE if CPU_FREQ diff --git a/arch/arm/mach-virt/Kconfig b/arch/arm/mach-virt/Kconfig index 8958f0d896bc..081d46929436 100644 --- a/arch/arm/mach-virt/Kconfig +++ b/arch/arm/mach-virt/Kconfig @@ -2,7 +2,7 @@ config ARCH_VIRT bool "Dummy Virtual Machine" if ARCH_MULTI_V7 select ARCH_WANT_OPTIONAL_GPIOLIB select ARM_GIC - select ARM_ARCH_TIMER + select HAVE_ARM_ARCH_TIMER select ARM_PSCI select HAVE_SMP select CPU_V7 -- cgit v1.2.1 From 3f71be237ce37e0131973ebfa33b326bc51d743e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 12 Mar 2013 14:56:12 +0000 Subject: ARM: arch_timer: stop virtual timer when booted in HYP mode 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 Acked-by: Santosh Shilimkar Cc: Dave Martin --- arch/arm/kernel/hyp-stub.S | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch') diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index dbe21107945a..4910232c4833 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 -- cgit v1.2.1