linux/arch/arm64/kernel/psci.c

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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright (C) 2013 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#define pr_fmt(fmt) "psci: " fmt
#include <linux/init.h>
#include <linux/of.h>
#include <linux/smp.h>
#include <linux/delay.h>
#include <linux/psci.h>
#include <uapi/linux/psci.h>
#include <asm/compiler.h>
#include <asm/cpu_ops.h>
#include <asm/errno.h>
#include <asm/smp_plat.h>
ARM64: kernel: make cpu_ops hooks DT agnostic ARM64 CPU operations such as cpu_init and cpu_init_idle take a struct device_node pointer as a parameter, which corresponds to the device tree node of the logical cpu on which the operation has to be applied. With the advent of ACPI on arm64, where MADT static table entries are used to initialize cpus, the device tree node parameter in cpu_ops hooks become useless when booting with ACPI, since in that case cpu device tree nodes are not present and can not be used for cpu initialization. The current cpu_init hook requires a struct device_node pointer parameter because it is called while parsing the device tree to initialize CPUs, when the cpu_logical_map (that is used to match a cpu node reg property to a device tree node) for a given logical cpu id is not set up yet. This means that the cpu_init hook cannot rely on the of_get_cpu_node function to retrieve the device tree node corresponding to the logical cpu id passed in as parameter, so the cpu device tree node must be passed in as a parameter to fix this catch-22 dependency cycle. This patch reshuffles the cpu_logical_map initialization code so that the cpu_init cpu_ops hook can safely use the of_get_cpu_node function to retrieve the cpu device tree node, removing the need for the device tree node pointer parameter. In the process, the patch removes device tree node parameters from all cpu_ops hooks, in preparation for SMP DT/ACPI cpus initialization consolidation. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Hanjun Guo <hanjun.guo@linaro.org> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Mark Rutland <mark.rutland@arm.com> [DT] Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-05-13 13:12:46 +00:00
static int __init cpu_psci_cpu_init(unsigned int cpu)
{
return 0;
}
static int __init cpu_psci_cpu_prepare(unsigned int cpu)
{
if (!psci_ops.cpu_on) {
pr_err("no cpu_on method, not booting CPU%d\n", cpu);
return -ENODEV;
}
return 0;
}
static int cpu_psci_cpu_boot(unsigned int cpu)
{
int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry));
if (err)
pr_err("failed to boot CPU%d (%d)\n", cpu, err);
return err;
}
#ifdef CONFIG_HOTPLUG_CPU
static int cpu_psci_cpu_disable(unsigned int cpu)
{
/* Fail early if we don't have CPU_OFF support */
if (!psci_ops.cpu_off)
return -EOPNOTSUPP;
/* Trusted OS will deny CPU_OFF */
if (psci_tos_resident_on(cpu))
return -EPERM;
return 0;
}
static void cpu_psci_cpu_die(unsigned int cpu)
{
int ret;
/*
* There are no known implementations of PSCI actually using the
* power state field, pass a sensible default for now.
*/
u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
PSCI_0_2_POWER_STATE_TYPE_SHIFT;
ret = psci_ops.cpu_off(state);
pr_crit("unable to power off CPU%u (%d)\n", cpu, ret);
}
static int cpu_psci_cpu_kill(unsigned int cpu)
{
int err, i;
if (!psci_ops.affinity_info)
return 0;
/*
* cpu_kill could race with cpu_die and we can
* potentially end up declaring this cpu undead
* while it is dying. So, try again a few times.
*/
for (i = 0; i < 10; i++) {
err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
pr_info("CPU%d killed.\n", cpu);
return 0;
}
msleep(10);
pr_info("Retrying again to check for CPU kill\n");
}
pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
cpu, err);
return -ETIMEDOUT;
}
#endif
const struct cpu_operations cpu_psci_ops = {
.name = "psci",
#ifdef CONFIG_CPU_IDLE
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>
2016-02-01 17:01:30 +00:00
.cpu_init_idle = psci_cpu_init_idle,
.cpu_suspend = psci_cpu_suspend_enter,
#endif
.cpu_init = cpu_psci_cpu_init,
.cpu_prepare = cpu_psci_cpu_prepare,
.cpu_boot = cpu_psci_cpu_boot,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = cpu_psci_cpu_disable,
.cpu_die = cpu_psci_cpu_die,
.cpu_kill = cpu_psci_cpu_kill,
#endif
};