Hi Sudeep,
On Tue, Jun 14, 2016 at 03:48:38PM +0100, Sudeep Holla wrote:
> This patch adds appropriate callbacks to support ACPI Low Power Idle
> (LPI) on ARM64.
>
> Now that arm_enter_idle_state is exactly same in both generic ARM{32,64}
> CPUIdle driver and ARM64 backend for ACPI processor idle driver, we can
> unify it and move to cpuidle-arm.h header.
>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> ---
> arch/arm64/kernel/cpuidle.c | 17 +++++++++++++
> drivers/cpuidle/cpuidle-arm.c | 23 ++----------------
> drivers/firmware/psci.c | 56 +++++++++++++++++++++++++++++++++++++++++++
> include/linux/cpuidle-arm.h | 30 +++++++++++++++++++++++
> 4 files changed, 105 insertions(+), 21 deletions(-)
> create mode 100644 include/linux/cpuidle-arm.h
This patch seems fine by me, it would be good if Daniel can have
a look too.
Some minor comments below.
[...]
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 03e04582791c..c6caa863d156 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -13,6 +13,7 @@
>
> #define pr_fmt(fmt) "psci: " fmt
>
> +#include <linux/acpi.h>
> #include <linux/arm-smccc.h>
> #include <linux/cpuidle.h>
> #include <linux/errno.h>
> @@ -310,11 +311,66 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
> return ret;
> }
>
> +#ifdef CONFIG_ACPI
> +#include <acpi/processor.h>
> +
> +static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
> +{
> + int i, count;
> + u32 *psci_states;
> + struct acpi_processor *pr;
> + struct acpi_lpi_state *lpi;
> +
> + pr = per_cpu(processors, cpu);
> + if (unlikely(!pr || !pr->flags.has_lpi))
> + return -EINVAL;
> +
> + /*
> + * If the PSCI cpu_suspend function hook has not been initialized
> + * idle states must not be enabled, so bail out
> + */
> + if (!psci_ops.cpu_suspend)
> + return -EOPNOTSUPP;
> +
> + count = pr->power.count - 1;
> + if (count <= 0)
> + return -ENODEV;
> +
> + psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
> + if (!psci_states)
> + return -ENOMEM;
> +
> + for (i = 0; i < count; i++) {
> + u32 state;
> +
> + lpi = &pr->power.lpi_states[i + 1];
> + state = lpi->address & 0xFFFFFFFF;
> + if (!psci_power_state_is_valid(state)) {
> + pr_warn("Invalid PSCI power state %#x\n", state);
> + kfree(psci_states);
> + return -EINVAL;
> + }
> + psci_states[i] = state;
> + }
> + /* Idle states parsed correctly, initialize per-cpu pointer */
> + per_cpu(psci_power_state, cpu) = psci_states;
> + return 0;
Most of the code in this function is FW independent, it would be nice
to factor it out and add the respective ACPI/DT helper functions to
retrieve idle states count and parameters, we can update it later
anyway it is fine by me to leave it as it is.
> +}
> +#else
> +static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
> +{
> + return -EINVAL;
> +}
> +#endif
> +
> int psci_cpu_init_idle(unsigned int cpu)
> {
> struct device_node *cpu_node;
> int ret;
>
> + if (!acpi_disabled)
> + return psci_acpi_cpu_init_idle(cpu);
> +
> cpu_node = of_get_cpu_node(cpu, NULL);
> if (!cpu_node)
> return -ENODEV;
> diff --git a/include/linux/cpuidle-arm.h b/include/linux/cpuidle-arm.h
> new file mode 100644
> index 000000000000..b99bcb3f43dd
> --- /dev/null
> +++ b/include/linux/cpuidle-arm.h
arm-cpuidle.h for consistency with other (ARM) include/linux files ?
> @@ -0,0 +1,30 @@
> +#include <linux/cpu_pm.h>
> +
> +#include <asm/cpuidle.h>
> +
> +/*
> + * arm_enter_idle_state - Programs CPU to enter the specified state
> + */
> +static int arm_generic_enter_idle_state(int idx)
> +{
> + int ret;
> +
> + if (!idx) {
> + cpu_do_idle();
> + return idx;
> + }
> +
> + ret = cpu_pm_enter();
> + if (!ret) {
> + /*
> + * Pass idle state index to cpu_suspend which in turn will
> + * call the CPU ops suspend protocol with idle index as a
> + * parameter.
> + */
> + ret = arm_cpuidle_suspend(idx);
> +
> + cpu_pm_exit();
> + }
> +
> + return ret ? -1 : idx;
> +}
Either you do this, or we have to add it somehow somewhere in
drivers/cpuidle to avoid duplicating it.
@Daniel: do you have an opinion on this please ?
Thanks,
Lorenzo
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