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author | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2019-08-09 12:03:12 +0100 |
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committer | Will Deacon <will@kernel.org> | 2019-08-09 17:51:39 +0100 |
commit | 9ffeb6d08c3a4bbd7b1e33711b241f511e2ded79 (patch) | |
tree | cd3d6211180de96c446af4cc90b62226f18bb576 /drivers/cpuidle | |
parent | 788961462f3471617749edf10d0fcafad410d2bb (diff) | |
download | linux-9ffeb6d08c3a4bbd7b1e33711b241f511e2ded79.tar.gz linux-9ffeb6d08c3a4bbd7b1e33711b241f511e2ded79.tar.bz2 linux-9ffeb6d08c3a4bbd7b1e33711b241f511e2ded79.zip |
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>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r-- | drivers/cpuidle/cpuidle-psci.c | 87 |
1 files changed, 86 insertions, 1 deletions
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index ab1dea918ea3..f3c1a2396f98 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -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; |