Commit fd2e0c73 authored Apr 23, 2015 by Mahesh Sivasubramanian Committed by Saravana Kannan Apr 30, 2020

ANDROID: GKI: arm64: psci: Support for OS initiated scheme



Existing PSCI implementation supports platform coordinated means of low
power modes where cluster low power modes are aggregated at the platform
level.  Adding support for OS initiated scheme, where the OS is
responsible for selecting cluster low power modes based on last man
determination. With OS initiated scheme, the OS can make better cluster
decisions based on wakeup times of CPUs within a cluster.

To this effect, in OS initiated schemes, the composite state ID is computed
by the idle driver before calling into the cpu_suspend API. The PSCI driver
is modified to use the composite ID to distinguish between retention and
non-retention states.

Change-Id: Iee5533676a28a8f6beb7942dcb908f2fa3518d78
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
(cherry picked from commit ea2c39ae)
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 154642337

parent 2e44b39d

drivers/firmware/psci.c

+8 −11

Original line number	Diff line number	Diff line
		@@ -397,29 +397,26 @@ int psci_cpu_init_idle(unsigned int cpu)
		return ret;
		}

		static int psci_suspend_finisher(unsigned long index)
		static int psci_suspend_finisher(unsigned long state_id)
		{
		u32 *state = __this_cpu_read(psci_power_state);

		return psci_ops.cpu_suspend(state[index - 1],
		return psci_ops.cpu_suspend(state_id,
		__pa_symbol(cpu_resume));
		}

		int psci_cpu_suspend_enter(unsigned long index)
		int psci_cpu_suspend_enter(unsigned long state_id)
		{
		int ret;
		u32 *state = __this_cpu_read(psci_power_state);

		/*
		* idle state index 0 corresponds to wfi, should never be called
		* from the cpu_suspend operations
		*/
		if (WARN_ON_ONCE(!index))
		if (WARN_ON_ONCE(!state_id))
		return -EINVAL;

		if (!psci_power_state_loses_context(state[index - 1]))
		ret = psci_ops.cpu_suspend(state[index - 1], 0);
		if (!psci_power_state_loses_context(state_id))
		ret = psci_ops.cpu_suspend(state_id, 0);
		else
		ret = cpu_suspend(index, psci_suspend_finisher);
		ret = cpu_suspend(state_id, psci_suspend_finisher);

		return ret;
		}