Merge branch 'depends/rmk-psci' into next/virt

This commit is contained in:
Olof Johansson 2013-02-11 09:05:45 -08:00
commit 3ad06d1a7d
7 changed files with 338 additions and 0 deletions

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@ -0,0 +1,55 @@
* Power State Coordination Interface (PSCI)
Firmware implementing the PSCI functions described in ARM document number
ARM DEN 0022A ("Power State Coordination Interface System Software on ARM
processors") can be used by Linux to initiate various CPU-centric power
operations.
Issue A of the specification describes functions for CPU suspend, hotplug
and migration of secure software.
Functions are invoked by trapping to the privilege level of the PSCI
firmware (specified as part of the binding below) and passing arguments
in a manner similar to that specified by AAPCS:
r0 => 32-bit Function ID / return value
{r1 - r3} => Parameters
Note that the immediate field of the trapping instruction must be set
to #0.
Main node required properties:
- compatible : Must be "arm,psci"
- method : The method of calling the PSCI firmware. Permitted
values are:
"smc" : SMC #0, with the register assignments specified
in this binding.
"hvc" : HVC #0, with the register assignments specified
in this binding.
Main node optional properties:
- cpu_suspend : Function ID for CPU_SUSPEND operation
- cpu_off : Function ID for CPU_OFF operation
- cpu_on : Function ID for CPU_ON operation
- migrate : Function ID for MIGRATE operation
Example:
psci {
compatible = "arm,psci";
method = "smc";
cpu_suspend = <0x95c10000>;
cpu_off = <0x95c10001>;
cpu_on = <0x95c10002>;
migrate = <0x95c10003>;
};

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@ -1622,6 +1622,16 @@ 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

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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) 2012 ARM Limited
*/
#ifndef __ASM_ARM_OPCODES_SEC_H
#define __ASM_ARM_OPCODES_SEC_H
#include <asm/opcodes.h>
#define __SMC(imm4) __inst_arm_thumb32( \
0xE1600070 | (((imm4) & 0xF) << 0), \
0xF7F08000 | (((imm4) & 0xF) << 16) \
)
#endif /* __ASM_ARM_OPCODES_SEC_H */

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@ -10,6 +10,7 @@
#define __ASM_ARM_OPCODES_H
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr);
#endif

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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) 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 */

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@ -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
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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) 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);