lkml.org 
[lkml]   [2022]   [Jun]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 5.15 069/667] cpuidle: PSCI: Improve support for suspend-to-RAM for PSCI OSI mode
    Date
    From: Ulf Hansson <ulf.hansson@linaro.org>

    [ Upstream commit 171b66e2e2e9d80b93c8cff799e6175074b22297 ]

    When PSCI OSI mode is supported the syscore flag is set for the CPU devices
    that becomes attached to their PM domains (genpds). In the suspend-to-idle
    case, we call dev_pm_genpd_suspend|resume() to allow genpd to properly
    manage the power-off/on operations (pick an idlestate and manage the on/off
    notifications).

    For suspend-to-ram, dev_pm_genpd_suspend|resume() is currently not being
    called, which causes a problem that the genpd on/off notifiers do not get
    sent as expected. This prevents the platform-specific operations from being
    executed, typically needed just before/after the boot CPU is being turned
    off/on.

    To deal with this problem, let's register a syscore ops for cpuidle-psci
    when PSCI OSI mode is being used and call dev_pm_genpd_suspend|resume()
    from them. In this way, genpd regains control of the PM domain topology and
    then sends the on/off notifications when it's appropriate.

    Reported-by: Maulik Shah <quic_mkshah@quicinc.com>
    Suggested-by: Maulik Shah <quic_mkshah@quicinc.com>
    Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
    Tested-by: Maulik Shah <quic_mkshah@quicinc.com>
    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/cpuidle/cpuidle-psci.c | 46 ++++++++++++++++++++++++++++++++++
    1 file changed, 46 insertions(+)

    diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
    index b51b5df08450..540105ca0781 100644
    --- a/drivers/cpuidle/cpuidle-psci.c
    +++ b/drivers/cpuidle/cpuidle-psci.c
    @@ -23,6 +23,7 @@
    #include <linux/pm_runtime.h>
    #include <linux/slab.h>
    #include <linux/string.h>
    +#include <linux/syscore_ops.h>

    #include <asm/cpuidle.h>

    @@ -131,6 +132,49 @@ static int psci_idle_cpuhp_down(unsigned int cpu)
    return 0;
    }

    +static void psci_idle_syscore_switch(bool suspend)
    +{
    + bool cleared = false;
    + struct device *dev;
    + int cpu;
    +
    + for_each_possible_cpu(cpu) {
    + dev = per_cpu_ptr(&psci_cpuidle_data, cpu)->dev;
    +
    + if (dev && suspend) {
    + dev_pm_genpd_suspend(dev);
    + } else if (dev) {
    + dev_pm_genpd_resume(dev);
    +
    + /* Account for userspace having offlined a CPU. */
    + if (pm_runtime_status_suspended(dev))
    + pm_runtime_set_active(dev);
    +
    + /* Clear domain state to re-start fresh. */
    + if (!cleared) {
    + psci_set_domain_state(0);
    + cleared = true;
    + }
    + }
    + }
    +}
    +
    +static int psci_idle_syscore_suspend(void)
    +{
    + psci_idle_syscore_switch(true);
    + return 0;
    +}
    +
    +static void psci_idle_syscore_resume(void)
    +{
    + psci_idle_syscore_switch(false);
    +}
    +
    +static struct syscore_ops psci_idle_syscore_ops = {
    + .suspend = psci_idle_syscore_suspend,
    + .resume = psci_idle_syscore_resume,
    +};
    +
    static void psci_idle_init_cpuhp(void)
    {
    int err;
    @@ -138,6 +182,8 @@ static void psci_idle_init_cpuhp(void)
    if (!psci_cpuidle_use_cpuhp)
    return;

    + register_syscore_ops(&psci_idle_syscore_ops);
    +
    err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
    "cpuidle/psci:online",
    psci_idle_cpuhp_up,
    --
    2.35.1


    \
     
     \ /
      Last update: 2022-06-07 20:23    [W:2.071 / U:0.420 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site