linux/drivers/idle, branch v4.7

intel_idle: add BXT support

2016-04-09T00:17:43Z

Broxton has all the HSW C-states, except C3. BXT C-state timing is slightly different. Here we trust the IRTL MSRs as authority on maximum C-state latency, and override the driver's tables with the values found in the associated IRTL MSRs. Further we set the target_residency to 1x maximum latency, trusting the hardware demotion logic. Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Add KBL support

2016-04-07T20:11:08Z

KBL is similar to SKL Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Add SKX support

2016-04-07T20:11:06Z

SKX is similar to BDX Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Clean up all registered devices on exit.

2016-04-07T20:11:05Z

This driver registers cpuidle devices when a CPU comes online, but it leaves the registrations in place when a CPU goes offline. The module exit code only unregisters the currently online CPUs, leaving the devices for offline CPUs dangling. This patch changes the driver to clean up all registrations on exit, even those from CPUs that are offline. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Propagate hot plug errors.

2016-04-07T20:11:02Z

If a cpuidle registration error occurs during the hot plug notifier callback, we should really inform the hot plug machinery instead of just ignoring the error. This patch changes the callback to properly return on error. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Don't overreact to a cpuidle registration failure.

2016-04-07T20:11:00Z

The helper function, intel_idle_cpu_init, registers one new device with the cpuidle layer. If the registration should fail, that function immediately calls intel_idle_cpuidle_devices_uninit() to unregister every last CPU's device. However, it makes no sense to do so, when called from the hot plug notifier callback. This patch moves the call to intel_idle_cpuidle_devices_uninit() outside of the helper function to the one call site that actually needs to perform the de-registrations. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Setup the timer broadcast only on successful driver load.

2016-04-07T20:10:58Z

This driver sets the broadcast tick quite early on during probe and does not clean up again in cast of failure. This patch moves the setup call after the registration, placing the on_each_cpu() calls within the global CPU lock region. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Avoid a double free of the per-CPU data.

2016-04-07T20:10:57Z

The helper function, intel_idle_cpuidle_devices_uninit, frees the globally allocated per-CPU data. However, this function is invoked from the hot plug notifier callback at a time when freeing that data is not safe. If the call to cpuidle_register_driver() should fail (say, due to lack of memory), then the driver will free its per-CPU region. On the *next* CPU_ONLINE event, the driver will happily use the region again and even free it again if the failure repeats. This patch fixes the issue by moving the call to free_percpu() outside of the helper function at the two call sites that actually need to free the per-CPU data. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Fix dangling registration on error path.

2016-04-07T20:10:56Z

In the module_init() method, if the per-CPU allocation fails, then the active cpuidle registration is not cleaned up. This patch fixes the issue by attempting the allocation before registration, and then cleaning it up again on registration failure. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki

intel_idle: Fix deallocation order on the driver exit path.

2016-04-07T20:10:54Z

In the module_exit() method, this driver first frees its per-CPU pointer, then unregisters a callback making use of the pointer. Furthermore, the function, intel_idle_cpuidle_devices_uninit, is racy against CPU hot plugging as it calls for_each_online_cpu(). This patch corrects the issues by unregistering first on the exit path while holding the hot plug lock. Signed-off-by: Richard Cochran Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki