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arm64: add PSCI CPU_SUSPEND based cpu_suspend support

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This patch implements the cpu_suspend cpu operations method through
the PSCI CPU SUSPEND API. The PSCI implementation translates the idle state
index passed by the cpu_suspend core call into a valid PSCI state according to
the PSCI states initialized at boot through the cpu_init_idle() CPU
operations hook.

The PSCI CPU suspend operation hook checks if the PSCI state is a
standby state. If it is, it calls the PSCI suspend implementation
straight away, without saving any context. If the state is a power
down state the kernel calls the __cpu_suspend API (that saves the CPU
context) and passed the PSCI suspend finisher as a parameter so that PSCI
can be called by the __cpu_suspend implementation after saving and flushing
the context as last function before power down.

For power down states, entry point is set to cpu_resume physical address,
that represents the default kernel execution address following a CPU reset.

Reviewed-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 18910ab0d9)
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>

Conflicts:
	arch/arm64/kernel/psci.c
This commit is contained in:
Lorenzo Pieralisi
2013-09-27 10:25:02 +01:00
committed by Huang, Tao
parent 32b8483751
commit 4c1b770ca3
1 changed files with 89 additions and 8 deletions
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97
arch/arm64/kernel/psci.c
View File

@@ -23,6 +23,7 @@
#include <linux/reboot.h>
#include <linux/pm.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <uapi/linux/psci.h>
#include <asm/compiler.h>
@@ -101,12 +102,13 @@ static u32 psci_power_state_pack(struct psci_power_state state)
static void psci_power_state_unpack(u32 power_state,
struct psci_power_state *state)
{
state->id = (power_state >> PSCI_0_2_POWER_STATE_ID_SHIFT)
& PSCI_0_2_POWER_STATE_ID_MASK;
state->type = (power_state >> PSCI_0_2_POWER_STATE_TYPE_SHIFT)
& PSCI_0_2_POWER_STATE_TYPE_MASK;
state->affinity_level = (power_state >> PSCI_0_2_POWER_STATE_AFFL_SHIFT)
& PSCI_0_2_POWER_STATE_AFFL_MASK;
state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
PSCI_0_2_POWER_STATE_ID_SHIFT;
state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
PSCI_0_2_POWER_STATE_TYPE_SHIFT;
state->affinity_level =
(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
PSCI_0_2_POWER_STATE_AFFL_SHIFT;
}
/*
@@ -215,6 +217,63 @@ static int psci_migrate_info_type(void)
return err;
}
static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
unsigned int cpu)
{
int i, ret, count = 0;
struct psci_power_state *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))) {
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++) {
u32 psci_power_state;
state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
ret = of_property_read_u32(state_node,
"arm,psci-suspend-param",
&psci_power_state);
if (ret) {
pr_warn(" * %s missing arm,psci-suspend-param property\n",
state_node->full_name);
of_node_put(state_node);
goto free_mem;
}
of_node_put(state_node);
pr_debug("psci-power-state %#x index %d\n", psci_power_state,
i);
psci_power_state_unpack(psci_power_state, &psci_states[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 int get_set_conduit_method(struct device_node *np)
{
const char *method;
@@ -453,19 +512,41 @@ static int cpu_psci_cpu_kill(unsigned int cpu)
#endif
#ifdef CONFIG_ARM64_CPU_SUSPEND
static int cpu_psci_cpu_suspend(unsigned long index)
static int psci_suspend_finisher(unsigned long index)
{
struct psci_power_state *state = __get_cpu_var(psci_power_state);
return psci_ops.cpu_suspend(state[index - 1],
virt_to_phys(cpu_resume));
}
static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
{
int ret;
struct psci_power_state *state = __get_cpu_var(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 (!state)
return -EOPNOTSUPP;
if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
ret = psci_ops.cpu_suspend(state[index - 1], 0);
else
ret = __cpu_suspend(index, psci_suspend_finisher);
return psci_ops.cpu_suspend(state[index], virt_to_phys(cpu_resume));
return ret;
}
#endif
const struct cpu_operations cpu_psci_ops = {
.name = "psci",
#ifdef CONFIG_CPU_IDLE
.cpu_init_idle = cpu_psci_cpu_init_idle,
#endif
#ifdef CONFIG_SMP
.cpu_init = cpu_psci_cpu_init,
.cpu_prepare = cpu_psci_cpu_prepare,