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yaml
---
r: 351197
b: refs/heads/master
c: e790f1d
h: refs/heads/master
i:
  351195: 467806b
v: v3
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Will Deacon authored and Catalin Marinas committed Jan 29, 2013
1 parent 40cfc87 commit 7369ad0
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Showing 5 changed files with 254 additions and 2 deletions.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: d329de3f2ada413c7cd16e1dc1d70d4abc7309e9
refs/heads/master: e790f1deb26a2e23f05dee0b9a5d4f764c3d7ea7
38 changes: 38 additions & 0 deletions trunk/arch/arm64/include/asm/psci.h
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@@ -0,0 +1,38 @@
/*
* 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
*/

#ifndef __ASM_PSCI_H
#define __ASM_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;

int psci_init(void);

#endif /* __ASM_PSCI_H */
2 changes: 1 addition & 1 deletion trunk/arch/arm64/kernel/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
entry-fpsimd.o process.o ptrace.o setup.o signal.o \
sys.o stacktrace.o time.o traps.o io.o vdso.o \
hyp-stub.o
hyp-stub.o psci.o

arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o
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211 changes: 211 additions & 0 deletions trunk/arch/arm64/kernel/psci.c
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@@ -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) 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 <asm/compiler.h>
#include <asm/errno.h>
#include <asm/psci.h>

struct psci_operations psci_ops;

static int (*invoke_psci_fn)(u64, u64, u64, u64);

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(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_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", },
{},
};

int __init psci_init(void)
{
struct device_node *np;
const char *method;
u32 id;
int err = 0;

np = of_find_matching_node(NULL, psci_of_match);
if (!np)
return -ENODEV;

pr_info("probing function IDs from device-tree\n");

if (of_property_read_string(np, "method", &method)) {
pr_warning("missing \"method\" property\n");
err = -ENXIO;
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);
err = -EINVAL;
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 err;
}
3 changes: 3 additions & 0 deletions trunk/arch/arm64/kernel/setup.c
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@
#include <asm/tlbflush.h>
#include <asm/traps.h>
#include <asm/memblock.h>
#include <asm/psci.h>

unsigned int processor_id;
EXPORT_SYMBOL(processor_id);
Expand Down Expand Up @@ -261,6 +262,8 @@ void __init setup_arch(char **cmdline_p)

unflatten_device_tree();

psci_init();

#ifdef CONFIG_SMP
smp_init_cpus();
#endif
Expand Down

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