summaryrefslogtreecommitdiffstats
path: root/drivers/firmware
diff options
context:
space:
mode:
authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2016-02-01 18:01:30 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2016-02-11 15:33:38 +0000
commit8b6f2499ac45d5a0ab2e4b6f9613ab3f60416be1 (patch)
treeaf0819f38904564e0c800e20674008b6e4ea6f84 /drivers/firmware
parent1b9bdf5c1661873a10e193b8cbb803a87fe5c4a1 (diff)
downloadop-kernel-dev-8b6f2499ac45d5a0ab2e4b6f9613ab3f60416be1.zip
op-kernel-dev-8b6f2499ac45d5a0ab2e4b6f9613ab3f60416be1.tar.gz
ARM: 8511/1: ARM64: kernel: PSCI: move PSCI idle management code to drivers/firmware
ARM64 PSCI kernel interfaces that initialize idle states and implement the suspend API to enter them are generic and can be shared with the ARM architecture. To achieve that goal, this patch moves ARM64 PSCI idle management code to drivers/firmware, so that the interface to initialize and enter idle states can actually be shared by ARM and ARM64 arches back-ends. The ARM generic CPUidle implementation also requires the definition of a cpuidle_ops section entry for the kernel to initialize the CPUidle operations at boot based on the enable-method (ie ARM64 has the statically initialized cpu_ops counterparts for that purpose); therefore this patch also adds the required section entry on CONFIG_ARM for PSCI so that the kernel can initialize the PSCI CPUidle back-end when PSCI is the probed enable-method. On ARM64 this patch provides no functional change. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arch/arm64] Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Jisheng Zhang <jszhang@marvell.com> Cc: Will Deacon <will.deacon@arm.com> 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: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/psci.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index f25cd79..11bfee8 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -14,6 +14,7 @@
#define pr_fmt(fmt) "psci: " fmt
#include <linux/arm-smccc.h>
+#include <linux/cpuidle.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/of.h>
@@ -21,10 +22,12 @@
#include <linux/printk.h>
#include <linux/psci.h>
#include <linux/reboot.h>
+#include <linux/slab.h>
#include <linux/suspend.h>
#include <uapi/linux/psci.h>
+#include <asm/cpuidle.h>
#include <asm/cputype.h>
#include <asm/system_misc.h>
#include <asm/smp_plat.h>
@@ -244,6 +247,123 @@ static int __init psci_features(u32 psci_func_id)
psci_func_id, 0, 0);
}
+#ifdef CONFIG_CPU_IDLE
+static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
+
+static int psci_dt_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_debug("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;
+}
+
+int psci_cpu_init_idle(unsigned int cpu)
+{
+ struct device_node *cpu_node;
+ int ret;
+
+ 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],
+ virt_to_phys(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);
+ else
+ ret = cpu_suspend(index, psci_suspend_finisher);
+
+ return ret;
+}
+
+/* ARM specific CPU idle operations */
+#ifdef CONFIG_ARM
+static struct cpuidle_ops psci_cpuidle_ops __initdata = {
+ .suspend = psci_cpu_suspend_enter,
+ .init = psci_dt_cpu_init_idle,
+};
+
+CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops);
+#endif
+#endif
+
static int psci_system_suspend(unsigned long unused)
{
return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
OpenPOWER on IntegriCloud