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PSCI: cpuidle: Refactor CPU suspend power_state parameter handling 

Current PSCI code handles idle state entry through the
psci_cpu_suspend_enter() API, that takes an idle state index as a
parameter and convert the index into a previously initialized
power_state parameter before calling the PSCI.CPU_SUSPEND() with it.

This is unwieldly, since it forces the PSCI firmware layer to keep track
of power_state parameter for every idle state so that the
index->power_state conversion can be made in the PSCI firmware layer
instead of the CPUidle driver implementations.

Move the power_state handling out of drivers/firmware/psci
into the respective ACPI/DT PSCI CPUidle backends and convert
the psci_cpu_suspend_enter() API to get the power_state
parameter as input, which makes it closer to its firmware
interface PSCI.CPU_SUSPEND() API.

A notable side effect is that the PSCI ACPI/DT CPUidle backends
now can directly handle (and if needed update) power_state
parameters before handing them over to the PSCI firmware
interface to trigger PSCI.CPU_SUSPEND() calls.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Lorenzo Pieralisi 2019-08-09 12:03:12 +01:00 committed by Will Deacon
parent 788961462f
commit 9ffeb6d08c
5 changed files with 154 additions and 160 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
arch/arm64/kernel/cpuidle.c
View File

@ -47,17 +47,58 @@ int arm_cpuidle_suspend(int index)
#define ARM64_LPI_IS_RETENTION_STATE(arch_flags) (!(arch_flags))
static int psci_acpi_cpu_init_idle(unsigned int cpu)
{
int i, count;
struct acpi_lpi_state *lpi;
struct acpi_processor *pr = per_cpu(processors, cpu);
/*
* 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 (unlikely(!pr || !pr->flags.has_lpi))
return -EINVAL;
count = pr->power.count - 1;
if (count <= 0)
return -ENODEV;
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);
return -EINVAL;
}
}
return 0;
}
int acpi_processor_ffh_lpi_probe(unsigned int cpu)
{
return psci_cpu_init_idle(cpu);
return psci_acpi_cpu_init_idle(cpu);
}
int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
{
u32 state = lpi->address;
if (ARM64_LPI_IS_RETENTION_STATE(lpi->arch_flags))
return CPU_PM_CPU_IDLE_ENTER_RETENTION(psci_cpu_suspend_enter,
lpi->index);
return CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(psci_cpu_suspend_enter,
lpi->index, state);
else
return CPU_PM_CPU_IDLE_ENTER(psci_cpu_suspend_enter, lpi->index);
return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter,
lpi->index, state);
}
#endif

87
drivers/cpuidle/cpuidle-psci.c
View File

@ -22,10 +22,15 @@
#include "dt_idle_states.h"
static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
static int psci_enter_idle_state(struct cpuidle_device *dev,
struct cpuidle_driver *drv, int idx)
{
return CPU_PM_CPU_IDLE_ENTER(psci_cpu_suspend_enter, idx);
u32 *state = __this_cpu_read(psci_power_state);
return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter,
idx, state[idx - 1]);
}
static struct cpuidle_driver psci_idle_driver __initdata = {
@ -51,6 +56,86 @@ static const struct of_device_id psci_idle_state_match[] __initconst = {
{ },
};
static int __init psci_dt_parse_state_node(struct device_node *np, u32 *state)
{
int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
if (err) {
pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
return err;
}
if (!psci_power_state_is_valid(*state)) {
pr_warn("Invalid PSCI power state %#x\n", *state);
return -EINVAL;
}
return 0;
}
static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
{
int i, ret = 0, count = 0;
u32 *psci_states;
struct device_node *state_node;
/* Count idle states */
while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
count))) {
count++;
of_node_put(state_node);
}
if (!count)
return -ENODEV;
psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
if (!psci_states)
return -ENOMEM;
for (i = 0; i < count; i++) {
state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
of_node_put(state_node);
if (ret)
goto free_mem;
pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
}
/* Idle states parsed correctly, initialize per-cpu pointer */
per_cpu(psci_power_state, cpu) = psci_states;
return 0;
free_mem:
kfree(psci_states);
return ret;
}
static __init 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;
cpu_node = of_cpu_device_node_get(cpu);
if (!cpu_node)
return -ENODEV;
ret = psci_dt_cpu_init_idle(cpu_node, cpu);
of_node_put(cpu_node);
return ret;
}
static int __init psci_idle_init_cpu(int cpu)
{
struct cpuidle_driver *drv;

157
drivers/firmware/psci/psci.c
View File

@ -103,7 +103,7 @@ static inline bool psci_power_state_loses_context(u32 state)
return state & mask;
}
static inline bool psci_power_state_is_valid(u32 state)
bool psci_power_state_is_valid(u32 state)
{
const u32 valid_mask = psci_has_ext_power_state() ?
PSCI_1_0_EXT_POWER_STATE_MASK :
@ -277,162 +277,21 @@ 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_parse_state_node(struct device_node *np, u32 *state)
static int psci_suspend_finisher(unsigned long state)
{
int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
u32 power_state = state;
if (err) {
pr_warn("%pOF missing arm,psci-suspend-param property\n", np);
return err;
}
if (!psci_power_state_is_valid(*state)) {
pr_warn("Invalid PSCI power state %#x\n", *state);
return -EINVAL;
}
return 0;
return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume));
}
static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
int psci_cpu_suspend_enter(u32 state)
{
int i, ret = 0, count = 0;
u32 *psci_states;
struct device_node *state_node;
/* Count idle states */
while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
count))) {
count++;
of_node_put(state_node);
}
if (!count)
return -ENODEV;
psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
if (!psci_states)
return -ENOMEM;
for (i = 0; i < count; i++) {
state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
ret = psci_dt_parse_state_node(state_node, &psci_states[i]);
of_node_put(state_node);
if (ret)
goto free_mem;
pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
}
/* Idle states parsed correctly, initialize per-cpu pointer */
per_cpu(psci_power_state, cpu) = psci_states;
return 0;
free_mem:
kfree(psci_states);
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;
ret = psci_dt_cpu_init_idle(cpu_node, cpu);
of_node_put(cpu_node);
return ret;
}
static int psci_suspend_finisher(unsigned long index)
{
u32 *state = __this_cpu_read(psci_power_state);
return psci_ops.cpu_suspend(state[index - 1],
__pa_symbol(cpu_resume));
}
int psci_cpu_suspend_enter(unsigned long index)
{
int ret;
u32 *state = __this_cpu_read(psci_power_state);
/*
* idle state index 0 corresponds to wfi, should never be called
* from the cpu_suspend operations
*/
if (WARN_ON_ONCE(!index))
return -EINVAL;
if (!psci_power_state_loses_context(state[index - 1]))
ret = psci_ops.cpu_suspend(state[index - 1], 0);
if (!psci_power_state_loses_context(state))
ret = psci_ops.cpu_suspend(state, 0);
else
ret = cpu_suspend(index, psci_suspend_finisher);
ret = cpu_suspend(state, psci_suspend_finisher);
return ret;
}

17
include/linux/cpuidle.h
View File

@ -256,7 +256,10 @@ static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
{return 0;}
#endif
#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, is_retention) \
#define __CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, \
idx, \
state, \
is_retention) \
({ \
int __ret = 0; \
\
@ -268,7 +271,7 @@ static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
if (!is_retention) \
__ret = cpu_pm_enter(); \
if (!__ret) { \
__ret = low_level_idle_enter(idx); \
__ret = low_level_idle_enter(state); \
if (!is_retention) \
cpu_pm_exit(); \
} \
@ -277,9 +280,15 @@ static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
})
#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx) \
__CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 0)
__CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 0)
#define CPU_PM_CPU_IDLE_ENTER_RETENTION(low_level_idle_enter, idx) \
__CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, 1)
__CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, idx, 1)
#define CPU_PM_CPU_IDLE_ENTER_PARAM(low_level_idle_enter, idx, state) \
__CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 0)
#define CPU_PM_CPU_IDLE_ENTER_RETENTION_PARAM(low_level_idle_enter, idx, state) \
__CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx, state, 1)
#endif /* _LINUX_CPUIDLE_H */

4
include/linux/psci.h
View File

@ -15,8 +15,8 @@
bool psci_tos_resident_on(int cpu);
int psci_cpu_init_idle(unsigned int cpu);
int psci_cpu_suspend_enter(unsigned long index);
int psci_cpu_suspend_enter(u32 state);
bool psci_power_state_is_valid(u32 state);
enum psci_conduit {
PSCI_CONDUIT_NONE,