lkml.org 
[lkml]   [2015]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 3/3] arm: psci: add cpuidle_ops support
Date
This patch implement cpuidle_ops using psci, the code is stolen from
arm64. Now we can use cpuidle-arm.c for both arm and arm64.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm/kernel/psci.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 116 insertions(+)

diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
index 7f6ff02..7bf744d 100644
--- a/arch/arm/kernel/psci.c
+++ b/arch/arm/kernel/psci.c
@@ -13,16 +13,132 @@
* Author: Will Deacon <will.deacon@arm.com>
*/

+#include <linux/cpuidle.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/psci.h>
+#include <linux/slab.h>

#include <uapi/linux/psci.h>

+#include <asm/cpuidle.h>
#include <asm/psci.h>
#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+
+#ifdef CONFIG_CPU_IDLE
+static bool psci_power_state_loses_context(u32 state)
+{
+ return state & PSCI_0_2_POWER_STATE_TYPE_MASK;
+}
+
+static bool psci_power_state_is_valid(u32 state)
+{
+ const u32 valid_mask = PSCI_0_2_POWER_STATE_ID_MASK |
+ PSCI_0_2_POWER_STATE_TYPE_MASK |
+ PSCI_0_2_POWER_STATE_AFFL_MASK;
+
+ return !(state & ~valid_mask);
+}
+
+static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
+
+static int __init cpu_psci_cpu_init_idle(struct device_node *cpu_node,
+ int cpu)
+{
+ int i, ret, count = 0;
+ u32 *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 state;
+
+ state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+
+ 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);
+ goto free_mem;
+ }
+
+ of_node_put(state_node);
+ pr_warn("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);
+ ret = -EINVAL;
+ goto free_mem;
+ }
+ psci_states[i] = state;
+ }
+ /* 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 psci_suspend_finisher(unsigned long index)
+{
+ u32 *state = __this_cpu_read(psci_power_state);
+
+ return psci_ops.cpu_suspend(state[index - 1],
+ virt_to_phys(cpu_resume));
+}
+
+static int cpu_psci_cpu_suspend(int cpu, 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);
+ else
+ ret = cpu_suspend(index, psci_suspend_finisher);
+
+ return ret;
+}
+
+static struct cpuidle_ops psci_cpuidle_ops __initdata = {
+ .suspend = cpu_psci_cpu_suspend,
+ .init = cpu_psci_cpu_init_idle,
+};
+CPUIDLE_METHOD_OF_DECLARE(psci_idle, "psci", &psci_cpuidle_ops);
+#endif

/*
* psci_smp assumes that the following is true about PSCI:
--
2.1.4


\
 
 \ /
  Last update: 2015-07-05 11:01    [W:0.057 / U:1.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site