mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-18 18:23:53 +08:00
ARM: psci: add support for PSCI invocations from the kernel
This patch adds support for the Power State Coordination Interface defined by ARM, allowing Linux to request CPU-centric power-management operations from firmware implementing the PSCI protocol. Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Will Deacon
parent
65397edfa1
commit
2bdd424f26
@ -1620,6 +1620,16 @@ config HOTPLUG_CPU
|
||||
Say Y here to experiment with turning CPUs off and on. CPUs
|
||||
can be controlled through /sys/devices/system/cpu.
|
||||
|
||||
config ARM_PSCI
|
||||
bool "Support for the ARM Power State Coordination Interface (PSCI)"
|
||||
depends on CPU_V7
|
||||
help
|
||||
Say Y here if you want Linux to communicate with system firmware
|
||||
implementing the PSCI specification for CPU-centric power
|
||||
management operations described in ARM document number ARM DEN
|
||||
0022A ("Power State Coordination Interface System Software on
|
||||
ARM processors").
|
||||
|
||||
config LOCAL_TIMERS
|
||||
bool "Use local timer interrupts"
|
||||
depends on SMP
|
||||
|
||||
36
arch/arm/include/asm/psci.h
Normal file
36
arch/arm/include/asm/psci.h
Normal file
@ -0,0 +1,36 @@
|
||||
/*
|
||||
* 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) 2012 ARM Limited
|
||||
*/
|
||||
|
||||
#ifndef __ASM_ARM_PSCI_H
|
||||
#define __ASM_ARM_PSCI_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);
|
||||
};
|
||||
|
||||
extern struct psci_operations psci_ops;
|
||||
|
||||
#endif /* __ASM_ARM_PSCI_H */
|
||||
@ -82,5 +82,6 @@ obj-$(CONFIG_DEBUG_LL) += debug.o
|
||||
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
|
||||
|
||||
obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o
|
||||
obj-$(CONFIG_ARM_PSCI) += psci.o
|
||||
|
||||
extra-y := $(head-y) vmlinux.lds
|
||||
|
||||
211
arch/arm/kernel/psci.c
Normal file
211
arch/arm/kernel/psci.c
Normal file
@ -0,0 +1,211 @@
|
||||
/*
|
||||
* 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) 2012 ARM Limited
|
||||
*
|
||||
* Author: Will Deacon <will.deacon@arm.com>
|
||||
*/
|
||||
|
||||
#define pr_fmt(fmt) "psci: " fmt
|
||||
|
||||
#include <linux/init.h>
|
||||
#include <linux/of.h>
|
||||
|
||||
#include <asm/compiler.h>
|
||||
#include <asm/errno.h>
|
||||
#include <asm/opcodes-sec.h>
|
||||
#include <asm/opcodes-virt.h>
|
||||
#include <asm/psci.h>
|
||||
|
||||
struct psci_operations psci_ops;
|
||||
|
||||
static int (*invoke_psci_fn)(u32, u32, u32, u32);
|
||||
|
||||
enum psci_function {
|
||||
PSCI_FN_CPU_SUSPEND,
|
||||
PSCI_FN_CPU_ON,
|
||||
PSCI_FN_CPU_OFF,
|
||||
PSCI_FN_MIGRATE,
|
||||
PSCI_FN_MAX,
|
||||
};
|
||||
|
||||
static u32 psci_function_id[PSCI_FN_MAX];
|
||||
|
||||
#define PSCI_RET_SUCCESS 0
|
||||
#define PSCI_RET_EOPNOTSUPP -1
|
||||
#define PSCI_RET_EINVAL -2
|
||||
#define PSCI_RET_EPERM -3
|
||||
|
||||
static int psci_to_linux_errno(int errno)
|
||||
{
|
||||
switch (errno) {
|
||||
case PSCI_RET_SUCCESS:
|
||||
return 0;
|
||||
case PSCI_RET_EOPNOTSUPP:
|
||||
return -EOPNOTSUPP;
|
||||
case PSCI_RET_EINVAL:
|
||||
return -EINVAL;
|
||||
case PSCI_RET_EPERM:
|
||||
return -EPERM;
|
||||
};
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
#define PSCI_POWER_STATE_ID_MASK 0xffff
|
||||
#define PSCI_POWER_STATE_ID_SHIFT 0
|
||||
#define PSCI_POWER_STATE_TYPE_MASK 0x1
|
||||
#define PSCI_POWER_STATE_TYPE_SHIFT 16
|
||||
#define PSCI_POWER_STATE_AFFL_MASK 0x3
|
||||
#define PSCI_POWER_STATE_AFFL_SHIFT 24
|
||||
|
||||
static u32 psci_power_state_pack(struct psci_power_state state)
|
||||
{
|
||||
return ((state.id & PSCI_POWER_STATE_ID_MASK)
|
||||
<< PSCI_POWER_STATE_ID_SHIFT) |
|
||||
((state.type & PSCI_POWER_STATE_TYPE_MASK)
|
||||
<< PSCI_POWER_STATE_TYPE_SHIFT) |
|
||||
((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
|
||||
<< PSCI_POWER_STATE_AFFL_SHIFT);
|
||||
}
|
||||
|
||||
/*
|
||||
* 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(u32 function_id, u32 arg0, u32 arg1,
|
||||
u32 arg2)
|
||||
{
|
||||
asm volatile(
|
||||
__asmeq("%0", "r0")
|
||||
__asmeq("%1", "r1")
|
||||
__asmeq("%2", "r2")
|
||||
__asmeq("%3", "r3")
|
||||
__HVC(0)
|
||||
: "+r" (function_id)
|
||||
: "r" (arg0), "r" (arg1), "r" (arg2));
|
||||
|
||||
return function_id;
|
||||
}
|
||||
|
||||
static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
|
||||
u32 arg2)
|
||||
{
|
||||
asm volatile(
|
||||
__asmeq("%0", "r0")
|
||||
__asmeq("%1", "r1")
|
||||
__asmeq("%2", "r2")
|
||||
__asmeq("%3", "r3")
|
||||
__SMC(0)
|
||||
: "+r" (function_id)
|
||||
: "r" (arg0), "r" (arg1), "r" (arg2));
|
||||
|
||||
return function_id;
|
||||
}
|
||||
|
||||
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 const struct of_device_id psci_of_match[] __initconst = {
|
||||
{ .compatible = "arm,psci", },
|
||||
{},
|
||||
};
|
||||
|
||||
static int __init psci_init(void)
|
||||
{
|
||||
struct device_node *np;
|
||||
const char *method;
|
||||
u32 id;
|
||||
|
||||
np = of_find_matching_node(NULL, psci_of_match);
|
||||
if (!np)
|
||||
return 0;
|
||||
|
||||
pr_info("probing function IDs from device-tree\n");
|
||||
|
||||
if (of_property_read_string(np, "method", &method)) {
|
||||
pr_warning("missing \"method\" property\n");
|
||||
goto out_put_node;
|
||||
}
|
||||
|
||||
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_warning("invalid \"method\" property: %s\n", method);
|
||||
goto out_put_node;
|
||||
}
|
||||
|
||||
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 0;
|
||||
}
|
||||
early_initcall(psci_init);
|
||||
Loading…
Reference in New Issue
Block a user