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drivers: firmware: psci: initialise idle states using ACPI LPI

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This patch adds support for initialisation of PSCI CPUIdle states
from Low Power Idle(_LPI) entries in the ACPI tables when acpi is
enabled.

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Sudeep Holla 2016-07-19 18:52:57 +01:00 committed by Rafael J. Wysocki
parent 220276e09b
commit c2a25c141f
1 changed files with 59 additions and 7 deletions
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66
drivers/firmware/psci.c
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@ -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>
@ -256,13 +257,6 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
u32 *psci_states;
struct device_node *state_node;
/*
* 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 idle states */
while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
count))) {
@ -310,11 +304,69 @@ 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_lpi_state *lpi;
struct acpi_processor *pr = per_cpu(processors, cpu);
if (unlikely(!pr || !pr->flags.has_lpi))
return -EINVAL;
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];
/*
* 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;
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;
}
#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 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;
if (!acpi_disabled)
return psci_acpi_cpu_init_idle(cpu);
cpu_node = of_get_cpu_node(cpu, NULL);
if (!cpu_node)
return -ENODEV;