This patch adds appropriate callbacks to support ACPI Low Power Idle
(LPI) on ARM64.
Cc: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Daniel Lezcano <daniel.lezc...@linaro.org>
Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com>
---
arch/arm64/kernel/cpuidle.c | 18 +++++++
drivers/firmware/psci.c | 122 ++++++++++++++++++++++++++++++++++++--------
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
