| Message ID | 1424972282-4822-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Feb 26, 2015 at 09:38:02AM -0800, Kamal Mostafa wrote: > https://launchpad.net/bugs/1426043 > > This upstream cherry-pick fixes boot failure on arm64. The patch has also > been applied to 3.13-stable. > > -Kamal > > ----- > > From: Catalin Marinas <catalin.marinas@arm.com> > Date: Wed, 10 Dec 2014 11:02:09 +0000 > Subject: clocksource: arch_timer: Only use the virtual counter (CNTVCT) on arm64 > > commit d6ad36913083d683aad4e02e53580c995f1a6ede upstream. > > Commit 0b46b8a718c6 (clocksource: arch_timer: Fix code to use physical > timers when requested) introduces the use of physical counters in the > ARM architected timer driver. However, he arm64 kernel uses CNTVCT in > VDSO. When booting in EL2, the kernel switches to the physical timers to > make things easier for KVM but it continues to use the virtual counter > both in user and kernel. While in such scenario CNTVCT == CNTPCT (since > CNTVOFF is initialised by the kernel to 0), we want to spot firmware > bugs corrupting CNTVOFF early (which would affect CNTVCT). > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Tested-by: Yingjoe Chen <yingjoe.chen@mediatek.com> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > BugLink: https://launchpad.net/bugs/1426043 > Signed-off-by: Kamal Mostafa <kamal@canonical.com> > --- > drivers/clocksource/arm_arch_timer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c > index 46884f8..a40fc66 100644 > --- a/drivers/clocksource/arm_arch_timer.c > +++ b/drivers/clocksource/arm_arch_timer.c > @@ -427,7 +427,7 @@ static void __init arch_counter_register(unsigned type) > > /* Register the CP15 based counter if we have one */ > if (type & ARCH_CP15_TIMER) { > - if (arch_timer_use_virtual) > + if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual) > arch_timer_read_counter = arch_counter_get_cntvct; > else > arch_timer_read_counter = arch_counter_get_cntpct; > -- > 1.9.1 > > > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team Clean cherry-pick from upstream.
On Thu, 2015-02-26 at 09:38 -0800, Kamal Mostafa wrote: > https://launchpad.net/bugs/1426043 > > This upstream cherry-pick fixes boot failure on arm64. The patch has also > been applied to 3.13-stable. > > -Kamal > > ----- > > From: Catalin Marinas <catalin.marinas@arm.com> > Date: Wed, 10 Dec 2014 11:02:09 +0000 > Subject: clocksource: arch_timer: Only use the virtual counter (CNTVCT) on arm64 > > commit d6ad36913083d683aad4e02e53580c995f1a6ede upstream. > > Commit 0b46b8a718c6 (clocksource: arch_timer: Fix code to use physical > timers when requested) introduces the use of physical counters in the > ARM architected timer driver. However, he arm64 kernel uses CNTVCT in > VDSO. When booting in EL2, the kernel switches to the physical timers to > make things easier for KVM but it continues to use the virtual counter > both in user and kernel. While in such scenario CNTVCT == CNTPCT (since > CNTVOFF is initialised by the kernel to 0), we want to spot firmware > bugs corrupting CNTVOFF early (which would affect CNTVCT). > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Tested-by: Yingjoe Chen <yingjoe.chen@mediatek.com> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > BugLink: https://launchpad.net/bugs/1426043 > Signed-off-by: Kamal Mostafa <kamal@canonical.com> > --- > drivers/clocksource/arm_arch_timer.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c > index 46884f8..a40fc66 100644 > --- a/drivers/clocksource/arm_arch_timer.c > +++ b/drivers/clocksource/arm_arch_timer.c > @@ -427,7 +427,7 @@ static void __init arch_counter_register(unsigned type) > > /* Register the CP15 based counter if we have one */ > if (type & ARCH_CP15_TIMER) { > - if (arch_timer_use_virtual) > + if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual) > arch_timer_read_counter = arch_counter_get_cntvct; > else > arch_timer_read_counter = arch_counter_get_cntpct; > -- > 1.9.1 > >
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 46884f8..a40fc66 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -427,7 +427,7 @@ static void __init arch_counter_register(unsigned type) /* Register the CP15 based counter if we have one */ if (type & ARCH_CP15_TIMER) { - if (arch_timer_use_virtual) + if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual) arch_timer_read_counter = arch_counter_get_cntvct; else arch_timer_read_counter = arch_counter_get_cntpct;