From 1595f452f3d8daa066bfd3ba4120754bed3329e1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 14 Oct 2007 22:57:45 +0200 Subject: clockevents: introduce force broadcast notifier The 64bit SMP bootup is slightly different to the 32bit one. It enables the boot CPU local APIC timer before all CPUs are brought up. Some AMD C1E systems have the C1E feature flag only set in the secondary CPU. Due to the early enable of the boot CPU local APIC timer the APIC timer is registered as a fully functional device. When we detect the wreckage during the bringup of the secondary CPU, we need to force the boot CPU into broadcast mode. Add a new notifier reason and implement the force broadcast in the clock events layer. Signed-off-by: Thomas Gleixner --- kernel/time/tick-broadcast.c | 29 +++++++++++++++++++++++------ kernel/time/tick-common.c | 1 + 2 files changed, 24 insertions(+), 6 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 298bc7c6f09f..fc3fc79b3d59 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -217,26 +217,43 @@ static void tick_do_broadcast_on_off(void *why) bc = tick_broadcast_device.evtdev; /* - * Is the device in broadcast mode forever or is it not - * affected by the powerstate ? + * Is the device not affected by the powerstate ? */ - if (!dev || !tick_device_is_functional(dev) || - !(dev->features & CLOCK_EVT_FEAT_C3STOP)) + if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP)) goto out; - if (*reason == CLOCK_EVT_NOTIFY_BROADCAST_ON) { + /* + * Defect device ? + */ + if (!tick_device_is_functional(dev)) { + /* + * AMD C1E wreckage fixup: + * + * Device was registered functional in the first + * place. Now the secondary CPU detected the C1E + * misfeature and notifies us to fix it up + */ + if (*reason != CLOCK_EVT_NOTIFY_BROADCAST_FORCE) + goto out; + } + + switch (*reason) { + case CLOCK_EVT_NOTIFY_BROADCAST_ON: + case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: if (!cpu_isset(cpu, tick_broadcast_mask)) { cpu_set(cpu, tick_broadcast_mask); if (td->mode == TICKDEV_MODE_PERIODIC) clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); } - } else { + break; + case CLOCK_EVT_NOTIFY_BROADCAST_OFF: if (cpu_isset(cpu, tick_broadcast_mask)) { cpu_clear(cpu, tick_broadcast_mask); if (td->mode == TICKDEV_MODE_PERIODIC) tick_setup_periodic(dev, 0); } + break; } if (cpus_empty(tick_broadcast_mask)) diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 3f3ae3907830..1bea399a9ef0 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -345,6 +345,7 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason, case CLOCK_EVT_NOTIFY_BROADCAST_ON: case CLOCK_EVT_NOTIFY_BROADCAST_OFF: + case CLOCK_EVT_NOTIFY_BROADCAST_FORCE: tick_broadcast_on_off(reason, dev); break; -- cgit v1.2.2