diff options
| author | Viresh Kumar <viresh.kumar@linaro.org> | 2014-06-10 13:52:25 +0530 |
|---|---|---|
| committer | Santosh Shukla <sshukla@mvista.com> | 2014-11-11 18:38:24 +0530 |
| commit | 30a047c4619aad422e7cfeece6e07623af573897 (patch) | |
| tree | b088552346d7a6b1c06a6772983c3ad175bde316 | |
| parent | 82bd0f7b17dfee53a707d9e21afeace69618d0a7 (diff) | |
clockevents: x86: add support for ONESHOT_STOPPED mode
Clockevent devices can be stopped from core (hrtimers/tick) when they aren't
used anymore. This will mostly happen on a idle or tickless cpu. This is done to
avoid getting spurious interrupts when core doesn't want to handle them anymore.
For stopping clockevent devices, core requests drivers to switch to a special
optional mode: CLOCK_EVT_MODE_ONESHOT_STOPPED. At this time platforms can also
save some power by disabling these devices.
This patch adds support for handling CLOCK_EVT_MODE_ONESHOT_STOPPED mode for x86
drivers.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Santosh Shukla <santosh.shukla@linaro.org>
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/hpet.c | 1 | ||||
| -rw-r--r-- | arch/x86/lguest/boot.c | 1 | ||||
| -rw-r--r-- | arch/x86/platform/uv/uv_time.c | 1 | ||||
| -rw-r--r-- | arch/x86/xen/time.c | 2 |
5 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 24e400e4f93c..c46e2204339b 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -508,6 +508,7 @@ static int lapic_timer_setup(enum clock_event_mode mode, break; case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT_STOPPED: v = apic_read(APIC_LVTT); v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); apic_write(APIC_LVTT, v); diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index ed1dad52ed0c..c29fdc12679c 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -350,6 +350,7 @@ static int hpet_set_mode(enum clock_event_mode mode, case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT_STOPPED: cfg = hpet_readl(HPET_Tn_CFG(timer)); cfg &= ~HPET_TN_ENABLE; hpet_writel(cfg, HPET_Tn_CFG(timer)); diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 264d2eddfe81..c175c299ca8c 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -968,6 +968,7 @@ static int lguest_clockevent_set_mode(enum clock_event_mode mode, switch (mode) { case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT_STOPPED: /* A 0 argument shuts the clock down. */ hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0, 0); break; diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c index 54f6b0cdbd9b..878361dd94c0 100644 --- a/arch/x86/platform/uv/uv_time.c +++ b/arch/x86/platform/uv/uv_time.c @@ -336,6 +336,7 @@ static int uv_rtc_timer_setup(enum clock_event_mode mode, break; case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT_STOPPED: uv_rtc_unset_timer(ced_cpu, 1); break; default: diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 952f00833cd7..51026acd6098 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -289,6 +289,7 @@ static int xen_timerop_set_mode(enum clock_event_mode mode, case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT_STOPPED: HYPERVISOR_set_timer_op(0); /* cancel timeout */ break; default: @@ -346,6 +347,7 @@ static int xen_vcpuop_set_mode(enum clock_event_mode mode, case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT_STOPPED: if (HYPERVISOR_vcpu_op(VCPUOP_stop_singleshot_timer, cpu, NULL) || HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer, cpu, NULL)) BUG(); |