linux-stable/arch/arm64/kernel/psci.c
Lorenzo Pieralisi b9e97ef93c arm64: kernel: add __init marker to PSCI init functions
PSCI init functions must be marked as __init so that they are freed
by the kernel upon boot.

This patch marks the PSCI init functions as such since they need not
be persistent in the kernel address space after the kernel has booted.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18 15:23:45 +01:00

452 lines
10 KiB
C

/*
* 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/reboot.h>
#include <linux/pm.h>
#include <linux/delay.h>
#include <uapi/linux/psci.h>
#include <asm/compiler.h>
#include <asm/cpu_ops.h>
#include <asm/errno.h>
#include <asm/psci.h>
#include <asm/smp_plat.h>
#include <asm/system_misc.h>
#define PSCI_POWER_STATE_TYPE_STANDBY 0
#define PSCI_POWER_STATE_TYPE_POWER_DOWN 1
struct psci_power_state {
u16 id;
u8 type;
u8 affinity_level;
};
struct psci_operations {
int (*cpu_suspend)(struct psci_power_state state,
unsigned long entry_point);
int (*cpu_off)(struct psci_power_state state);
int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
int (*migrate)(unsigned long cpuid);
int (*affinity_info)(unsigned long target_affinity,
unsigned long lowest_affinity_level);
int (*migrate_info_type)(void);
};
static struct psci_operations psci_ops;
static int (*invoke_psci_fn)(u64, u64, u64, u64);
typedef int (*psci_initcall_t)(const struct device_node *);
enum psci_function {
PSCI_FN_CPU_SUSPEND,
PSCI_FN_CPU_ON,
PSCI_FN_CPU_OFF,
PSCI_FN_MIGRATE,
PSCI_FN_AFFINITY_INFO,
PSCI_FN_MIGRATE_INFO_TYPE,
PSCI_FN_MAX,
};
static u32 psci_function_id[PSCI_FN_MAX];
static int psci_to_linux_errno(int errno)
{
switch (errno) {
case PSCI_RET_SUCCESS:
return 0;
case PSCI_RET_NOT_SUPPORTED:
return -EOPNOTSUPP;
case PSCI_RET_INVALID_PARAMS:
return -EINVAL;
case PSCI_RET_DENIED:
return -EPERM;
};
return -EINVAL;
}
static u32 psci_power_state_pack(struct psci_power_state state)
{
return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
& PSCI_0_2_POWER_STATE_ID_MASK) |
((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
& PSCI_0_2_POWER_STATE_TYPE_MASK) |
((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
& PSCI_0_2_POWER_STATE_AFFL_MASK);
}
/*
* The following two functions are invoked via the invoke_psci_fn pointer
* and will not be inlined, allowing us to piggyback on the AAPCS.
*/
static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"hvc #0\n"
: "+r" (function_id)
: "r" (arg0), "r" (arg1), "r" (arg2));
return function_id;
}
static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"smc #0\n"
: "+r" (function_id)
: "r" (arg0), "r" (arg1), "r" (arg2));
return function_id;
}
static int psci_get_version(void)
{
int err;
err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
return err;
}
static int psci_cpu_suspend(struct psci_power_state state,
unsigned long entry_point)
{
int err;
u32 fn, power_state;
fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
power_state = psci_power_state_pack(state);
err = invoke_psci_fn(fn, power_state, entry_point, 0);
return psci_to_linux_errno(err);
}
static int psci_cpu_off(struct psci_power_state state)
{
int err;
u32 fn, power_state;
fn = psci_function_id[PSCI_FN_CPU_OFF];
power_state = psci_power_state_pack(state);
err = invoke_psci_fn(fn, power_state, 0, 0);
return psci_to_linux_errno(err);
}
static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
{
int err;
u32 fn;
fn = psci_function_id[PSCI_FN_CPU_ON];
err = invoke_psci_fn(fn, cpuid, entry_point, 0);
return psci_to_linux_errno(err);
}
static int psci_migrate(unsigned long cpuid)
{
int err;
u32 fn;
fn = psci_function_id[PSCI_FN_MIGRATE];
err = invoke_psci_fn(fn, cpuid, 0, 0);
return psci_to_linux_errno(err);
}
static int psci_affinity_info(unsigned long target_affinity,
unsigned long lowest_affinity_level)
{
int err;
u32 fn;
fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
return err;
}
static int psci_migrate_info_type(void)
{
int err;
u32 fn;
fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
err = invoke_psci_fn(fn, 0, 0, 0);
return err;
}
static int get_set_conduit_method(struct device_node *np)
{
const char *method;
pr_info("probing for conduit method from DT.\n");
if (of_property_read_string(np, "method", &method)) {
pr_warn("missing \"method\" property\n");
return -ENXIO;
}
if (!strcmp("hvc", method)) {
invoke_psci_fn = __invoke_psci_fn_hvc;
} else if (!strcmp("smc", method)) {
invoke_psci_fn = __invoke_psci_fn_smc;
} else {
pr_warn("invalid \"method\" property: %s\n", method);
return -EINVAL;
}
return 0;
}
static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
{
invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
}
static void psci_sys_poweroff(void)
{
invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
}
/*
* PSCI Function IDs for v0.2+ are well defined so use
* standard values.
*/
static int __init psci_0_2_init(struct device_node *np)
{
int err, ver;
err = get_set_conduit_method(np);
if (err)
goto out_put_node;
ver = psci_get_version();
if (ver == PSCI_RET_NOT_SUPPORTED) {
/* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
err = -EOPNOTSUPP;
goto out_put_node;
} else {
pr_info("PSCIv%d.%d detected in firmware.\n",
PSCI_VERSION_MAJOR(ver),
PSCI_VERSION_MINOR(ver));
if (PSCI_VERSION_MAJOR(ver) == 0 &&
PSCI_VERSION_MINOR(ver) < 2) {
err = -EINVAL;
pr_err("Conflicting PSCI version detected.\n");
goto out_put_node;
}
}
pr_info("Using standard PSCI v0.2 function IDs\n");
psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND;
psci_ops.cpu_suspend = psci_cpu_suspend;
psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
psci_ops.cpu_off = psci_cpu_off;
psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON;
psci_ops.cpu_on = psci_cpu_on;
psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
psci_ops.migrate = psci_migrate;
psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO;
psci_ops.affinity_info = psci_affinity_info;
psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
PSCI_0_2_FN_MIGRATE_INFO_TYPE;
psci_ops.migrate_info_type = psci_migrate_info_type;
arm_pm_restart = psci_sys_reset;
pm_power_off = psci_sys_poweroff;
out_put_node:
of_node_put(np);
return err;
}
/*
* PSCI < v0.2 get PSCI Function IDs via DT.
*/
static int __init psci_0_1_init(struct device_node *np)
{
u32 id;
int err;
err = get_set_conduit_method(np);
if (err)
goto out_put_node;
pr_info("Using PSCI v0.1 Function IDs from DT\n");
if (!of_property_read_u32(np, "cpu_suspend", &id)) {
psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
psci_ops.cpu_suspend = psci_cpu_suspend;
}
if (!of_property_read_u32(np, "cpu_off", &id)) {
psci_function_id[PSCI_FN_CPU_OFF] = id;
psci_ops.cpu_off = psci_cpu_off;
}
if (!of_property_read_u32(np, "cpu_on", &id)) {
psci_function_id[PSCI_FN_CPU_ON] = id;
psci_ops.cpu_on = psci_cpu_on;
}
if (!of_property_read_u32(np, "migrate", &id)) {
psci_function_id[PSCI_FN_MIGRATE] = id;
psci_ops.migrate = psci_migrate;
}
out_put_node:
of_node_put(np);
return err;
}
static const struct of_device_id psci_of_match[] __initconst = {
{ .compatible = "arm,psci", .data = psci_0_1_init},
{ .compatible = "arm,psci-0.2", .data = psci_0_2_init},
{},
};
int __init psci_init(void)
{
struct device_node *np;
const struct of_device_id *matched_np;
psci_initcall_t init_fn;
np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
if (!np)
return -ENODEV;
init_fn = (psci_initcall_t)matched_np->data;
return init_fn(np);
}
#ifdef CONFIG_SMP
static int __init cpu_psci_cpu_init(struct device_node *dn, 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;
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.
*/
struct psci_power_state state = {
.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
};
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 1;
/*
* 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 1;
}
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);
/* Make op_cpu_kill() fail. */
return 0;
}
#endif
#endif
const struct cpu_operations cpu_psci_ops = {
.name = "psci",
#ifdef CONFIG_SMP
.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
#endif
};