lkml.org 
[lkml]   [2019]   [Jul]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 6/6] PSCI: cpuidle: Refactor CPU suspend power_state parameter handling
Date
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>
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>
---
arch/arm64/kernel/cpuidle.c | 47 +++++++++-
drivers/cpuidle/cpuidle-psci.c | 87 +++++++++++++++++-
drivers/firmware/psci/psci.c | 158 ++-------------------------------
include/linux/cpuidle.h | 17 +++-
include/linux/psci.h | 4 +-
5 files changed, 153 insertions(+), 160 deletions(-)

diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
index 4bcd1bca0dfc..e4d6af2fdec7 100644
--- a/arch/arm64/kernel/cpuidle.c
+++ b/arch/arm64/kernel/cpuidle.c
@@ -47,6 +47,44 @@ 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_acpi_cpu_init_idle(cpu);
@@ -54,10 +92,13 @@ int acpi_processor_ffh_lpi_probe(unsigned int 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
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index bdf02600e4e2..7485b3abe372 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -21,10 +21,15 @@

#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 = {
@@ -50,6 +55,86 @@ 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_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 __init psci_idle_init_cpu(int cpu)
{
struct cpuidle_driver *drv;
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index bae734d13a52..84f4ff351c62 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -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 :
@@ -277,167 +277,25 @@ 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 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 psci_cpu_suspend_enter(u32 state)
{
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;
}
#endif
-#endif

static int psci_system_suspend(unsigned long unused)
{
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index bb9a0db89f1a..12ae4b87494e 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -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 */
diff --git a/include/linux/psci.h b/include/linux/psci.h
index a8a15613c157..e2bacc6fd2f2 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -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,
--
2.21.0
\
 
 \ /
  Last update: 2019-07-22 17:39    [W:0.197 / U:21.220 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site