[PATCH v8 5/6] arm64: add support for ACPI Low Power Idle(LPI)
Lorenzo Pieralisi
lorenzo.pieralisi at arm.com
Fri Jul 8 07:47:19 PDT 2016
On Thu, Jul 07, 2016 at 06:10:50PM +0100, Sudeep Holla wrote:
> This patch adds appropriate callbacks to support ACPI Low Power Idle
> (LPI) on ARM64.
>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Cc: "Rafael J. Wysocki" <rjw at rjwysocki.net>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---
> arch/arm64/kernel/cpuidle.c | 18 +++++++
> drivers/firmware/psci.c | 122 ++++++++++++++++++++++++++++++++++++--------
I would split this patch in two (ARM64 cpuidle and PSCI) and for
the PSCI code (apologies, blame taken, it is entirely my fault) I
think that the code in v6 was better, I asked you to factor out
DT/ACPI idle states count and parameter retrieval but the end result
is much more complicated than what it was in v6, so for PSCI ACPI
idle states parsing I would revert to v6, apologies.
With changes above:
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi at arm.com>
> 2 files changed, 118 insertions(+), 22 deletions(-)
>
> diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
> index 06786fdaadeb..7f16df7d7b23 100644
> --- a/arch/arm64/kernel/cpuidle.c
> +++ b/arch/arm64/kernel/cpuidle.c
> @@ -9,6 +9,9 @@
> * published by the Free Software Foundation.
> */
>
> +#include <linux/acpi.h>
> +#include <linux/cpuidle.h>
> +#include <linux/cpu_pm.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
>
> @@ -39,3 +42,18 @@ int arm_cpuidle_suspend(int index)
>
> return cpu_ops[cpu]->cpu_suspend(index);
> }
> +
> +#ifdef CONFIG_ACPI
> +
> +#include <acpi/processor.h>
> +
> +int acpi_processor_ffh_lpi_probe(unsigned int cpu)
> +{
> + return arm_cpuidle_init(cpu);
> +}
> +
> +int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
> +{
> + return CPU_IDLE_ENTER_WRAPPED(arm_cpuidle_suspend, lpi->index);
> +}
> +#endif
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 03e04582791c..edd83c884a1d 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>
> @@ -250,12 +251,84 @@ static int __init psci_features(u32 psci_func_id)
> #ifdef CONFIG_CPU_IDLE
> static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
>
> -static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
> +static int psci_dt_get_state_count(struct device_node *cpu_dn)
> {
> - int i, ret, count = 0;
> - u32 *psci_states;
> + int count = 0;
> struct device_node *state_node;
>
> + /* Count idle states */
> + while ((state_node = of_parse_phandle(cpu_dn, "cpu-idle-states",
> + count))) {
> + count++;
> + of_node_put(state_node);
> + }
> +
> + return count;
> +}
> +
> +static int psci_dt_get_idle_state(struct device_node *node, int idx, u32 *state)
> +{
> + int ret;
> + struct device_node *state_node;
> +
> + state_node = of_parse_phandle(node, "cpu-idle-states", idx);
> +
> + ret = of_property_read_u32(state_node, "arm,psci-suspend-param",
> + state);
> + if (ret)
> + pr_warn(" * %s missing arm,psci-suspend-param property\n",
> + state_node->full_name);
> +
> + of_node_put(state_node);
> +
> + return ret;
> +}
> +
> +#ifdef CONFIG_ACPI
> +#include <acpi/processor.h>
> +
> +static int psci_acpi_get_state_count(unsigned int cpu)
> +{
> + struct acpi_processor *pr = per_cpu(processors, cpu);
> +
> + if (unlikely(!pr || !pr->flags.has_lpi))
> + return -EINVAL;
> +
> + return pr->power.count - 1;
> +}
> +
> +static int psci_acpi_get_idle_state(unsigned int cpu, int idx, u32 *state)
> +{
> + struct acpi_processor *pr = per_cpu(processors, cpu);
> + struct acpi_lpi_state *lpi = &pr->power.lpi_states[idx + 1];
> +
> + if (!lpi)
> + return -EINVAL;
> +
> + /*
> + * Only bits[31:0] represent a PSCI power_state while
> + * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
> + */
> + *state = lpi->address;
> + return 0;
> +}
> +#else
> +static int psci_acpi_get_state_count(unsigned int cpu)
> +{
> + return -EINVAL;
> +}
> +
> +static int psci_acpi_get_idle_state(unsigned int cpu, int idx, u32 *state)
> +{
> + return -EINVAL;
> +}
> +#endif
> +
> +static int __psci_cpu_init_idle(struct device_node *cpu_dn, int cpu, bool acpi)
> +{
> + int i, count, ret;
> + u32 *psci_states;
> +
> /*
> * If the PSCI cpu_suspend function hook has not been initialized
> * idle states must not be enabled, so bail out
> @@ -263,14 +336,12 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
> if (!psci_ops.cpu_suspend)
> return -EOPNOTSUPP;
>
> - /* Count idle states */
> - while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
> - count))) {
> - count++;
> - of_node_put(state_node);
> - }
> + if (acpi)
> + count = psci_acpi_get_state_count(cpu);
> + else
> + count = psci_dt_get_state_count(cpu_dn);
>
> - if (!count)
> + if (count <= 0)
> return -ENODEV;
>
> psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
> @@ -278,21 +349,15 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
> return -ENOMEM;
>
> for (i = 0; i < count; i++) {
> - u32 state;
> -
> - state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
> + u32 state = 0;
>
> - ret = of_property_read_u32(state_node,
> - "arm,psci-suspend-param",
> - &state);
> - if (ret) {
> - pr_warn(" * %s missing arm,psci-suspend-param property\n",
> - state_node->full_name);
> - of_node_put(state_node);
> + if (acpi)
> + ret = psci_acpi_get_idle_state(cpu, i, &state);
> + else
> + ret = psci_dt_get_idle_state(cpu_dn, i, &state);
> + if (ret)
> goto free_mem;
> - }
>
> - of_node_put(state_node);
> pr_debug("psci-power-state %#x index %d\n", state, i);
> if (!psci_power_state_is_valid(state)) {
> pr_warn("Invalid PSCI power state %#x\n", state);
> @@ -310,11 +375,24 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
> return ret;
> }
>
> +static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
> +{
> + return __psci_cpu_init_idle(cpu_node, cpu, false);
> +}
> +
> +static int psci_acpi_cpu_init_idle(unsigned int cpu)
> +{
> + return __psci_cpu_init_idle(NULL, cpu, true);
> +}
> +
> 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;
> --
> 2.7.4
>
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