aboutsummaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorWill Deacon <will.deacon@arm.com>2012-12-18 12:53:14 -0500
committerCatalin Marinas <catalin.marinas@arm.com>2013-01-29 11:56:37 -0500
commite790f1deb26a2e23f05dee0b9a5d4f764c3d7ea7 (patch)
treea562c97caa8662497320ef03930d37cde1395d97 /arch
parentd329de3f2ada413c7cd16e1dc1d70d4abc7309e9 (diff)
arm64: 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. Signed-off-by: Will Deacon <will.deacon@arm.com> [Marc: s/u32/u64/ in the relevant spots, and switch from an initcall to an simpler init function] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/psci.h38
-rw-r--r--arch/arm64/kernel/Makefile2
-rw-r--r--arch/arm64/kernel/psci.c211
-rw-r--r--arch/arm64/kernel/setup.c3
4 files changed, 253 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/psci.h b/arch/arm64/include/asm/psci.h
new file mode 100644
index 000000000000..0604237ecd99
--- /dev/null
+++ b/arch/arm64/include/asm/psci.h
@@ -0,0 +1,38 @@
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2013 ARM Limited
12 */
13
14#ifndef __ASM_PSCI_H
15#define __ASM_PSCI_H
16
17#define PSCI_POWER_STATE_TYPE_STANDBY 0
18#define PSCI_POWER_STATE_TYPE_POWER_DOWN 1
19
20struct psci_power_state {
21 u16 id;
22 u8 type;
23 u8 affinity_level;
24};
25
26struct psci_operations {
27 int (*cpu_suspend)(struct psci_power_state state,
28 unsigned long entry_point);
29 int (*cpu_off)(struct psci_power_state state);
30 int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
31 int (*migrate)(unsigned long cpuid);
32};
33
34extern struct psci_operations psci_ops;
35
36int psci_init(void);
37
38#endif /* __ASM_PSCI_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index ac1b6823334c..75a90c15b30b 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -9,7 +9,7 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
9arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \ 9arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
10 entry-fpsimd.o process.o ptrace.o setup.o signal.o \ 10 entry-fpsimd.o process.o ptrace.o setup.o signal.o \
11 sys.o stacktrace.o time.o traps.o io.o vdso.o \ 11 sys.o stacktrace.o time.o traps.o io.o vdso.o \
12 hyp-stub.o 12 hyp-stub.o psci.o
13 13
14arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \ 14arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
15 sys_compat.o 15 sys_compat.o
diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
new file mode 100644
index 000000000000..14f73c445ff5
--- /dev/null
+++ b/arch/arm64/kernel/psci.c
@@ -0,0 +1,211 @@
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2 as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * Copyright (C) 2013 ARM Limited
12 *
13 * Author: Will Deacon <will.deacon@arm.com>
14 */
15
16#define pr_fmt(fmt) "psci: " fmt
17
18#include <linux/init.h>
19#include <linux/of.h>
20
21#include <asm/compiler.h>
22#include <asm/errno.h>
23#include <asm/psci.h>
24
25struct psci_operations psci_ops;
26
27static int (*invoke_psci_fn)(u64, u64, u64, u64);
28
29enum psci_function {
30 PSCI_FN_CPU_SUSPEND,
31 PSCI_FN_CPU_ON,
32 PSCI_FN_CPU_OFF,
33 PSCI_FN_MIGRATE,
34 PSCI_FN_MAX,
35};
36
37static u32 psci_function_id[PSCI_FN_MAX];
38
39#define PSCI_RET_SUCCESS 0
40#define PSCI_RET_EOPNOTSUPP -1
41#define PSCI_RET_EINVAL -2
42#define PSCI_RET_EPERM -3
43
44static int psci_to_linux_errno(int errno)
45{
46 switch (errno) {
47 case PSCI_RET_SUCCESS:
48 return 0;
49 case PSCI_RET_EOPNOTSUPP:
50 return -EOPNOTSUPP;
51 case PSCI_RET_EINVAL:
52 return -EINVAL;
53 case PSCI_RET_EPERM:
54 return -EPERM;
55 };
56
57 return -EINVAL;
58}
59
60#define PSCI_POWER_STATE_ID_MASK 0xffff
61#define PSCI_POWER_STATE_ID_SHIFT 0
62#define PSCI_POWER_STATE_TYPE_MASK 0x1
63#define PSCI_POWER_STATE_TYPE_SHIFT 16
64#define PSCI_POWER_STATE_AFFL_MASK 0x3
65#define PSCI_POWER_STATE_AFFL_SHIFT 24
66
67static u32 psci_power_state_pack(struct psci_power_state state)
68{
69 return ((state.id & PSCI_POWER_STATE_ID_MASK)
70 << PSCI_POWER_STATE_ID_SHIFT) |
71 ((state.type & PSCI_POWER_STATE_TYPE_MASK)
72 << PSCI_POWER_STATE_TYPE_SHIFT) |
73 ((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
74 << PSCI_POWER_STATE_AFFL_SHIFT);
75}
76
77/*
78 * The following two functions are invoked via the invoke_psci_fn pointer
79 * and will not be inlined, allowing us to piggyback on the AAPCS.
80 */
81static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
82 u64 arg2)
83{
84 asm volatile(
85 __asmeq("%0", "x0")
86 __asmeq("%1", "x1")
87 __asmeq("%2", "x2")
88 __asmeq("%3", "x3")
89 "hvc #0\n"
90 : "+r" (function_id)
91 : "r" (arg0), "r" (arg1), "r" (arg2));
92
93 return function_id;
94}
95
96static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
97 u64 arg2)
98{
99 asm volatile(
100 __asmeq("%0", "x0")
101 __asmeq("%1", "x1")
102 __asmeq("%2", "x2")
103 __asmeq("%3", "x3")
104 "smc #0\n"
105 : "+r" (function_id)
106 : "r" (arg0), "r" (arg1), "r" (arg2));
107
108 return function_id;
109}
110
111static int psci_cpu_suspend(struct psci_power_state state,
112 unsigned long entry_point)
113{
114 int err;
115 u32 fn, power_state;
116
117 fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
118 power_state = psci_power_state_pack(state);
119 err = invoke_psci_fn(fn, power_state, entry_point, 0);
120 return psci_to_linux_errno(err);
121}
122
123static int psci_cpu_off(struct psci_power_state state)
124{
125 int err;
126 u32 fn, power_state;
127
128 fn = psci_function_id[PSCI_FN_CPU_OFF];
129 power_state = psci_power_state_pack(state);
130 err = invoke_psci_fn(fn, power_state, 0, 0);
131 return psci_to_linux_errno(err);
132}
133
134static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
135{
136 int err;
137 u32 fn;
138
139 fn = psci_function_id[PSCI_FN_CPU_ON];
140 err = invoke_psci_fn(fn, cpuid, entry_point, 0);
141 return psci_to_linux_errno(err);
142}
143
144static int psci_migrate(unsigned long cpuid)
145{
146 int err;
147 u32 fn;
148
149 fn = psci_function_id[PSCI_FN_MIGRATE];
150 err = invoke_psci_fn(fn, cpuid, 0, 0);
151 return psci_to_linux_errno(err);
152}
153
154static const struct of_device_id psci_of_match[] __initconst = {
155 { .compatible = "arm,psci", },
156 {},
157};
158
159int __init psci_init(void)
160{
161 struct device_node *np;
162 const char *method;
163 u32 id;
164 int err = 0;
165
166 np = of_find_matching_node(NULL, psci_of_match);
167 if (!np)
168 return -ENODEV;
169
170 pr_info("probing function IDs from device-tree\n");
171
172 if (of_property_read_string(np, "method", &method)) {
173 pr_warning("missing \"method\" property\n");
174 err = -ENXIO;
175 goto out_put_node;
176 }
177
178 if (!strcmp("hvc", method)) {
179 invoke_psci_fn = __invoke_psci_fn_hvc;
180 } else if (!strcmp("smc", method)) {
181 invoke_psci_fn = __invoke_psci_fn_smc;
182 } else {
183 pr_warning("invalid \"method\" property: %s\n", method);
184 err = -EINVAL;
185 goto out_put_node;
186 }
187
188 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
189 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
190 psci_ops.cpu_suspend = psci_cpu_suspend;
191 }
192
193 if (!of_property_read_u32(np, "cpu_off", &id)) {
194 psci_function_id[PSCI_FN_CPU_OFF] = id;
195 psci_ops.cpu_off = psci_cpu_off;
196 }
197
198 if (!of_property_read_u32(np, "cpu_on", &id)) {
199 psci_function_id[PSCI_FN_CPU_ON] = id;
200 psci_ops.cpu_on = psci_cpu_on;
201 }
202
203 if (!of_property_read_u32(np, "migrate", &id)) {
204 psci_function_id[PSCI_FN_MIGRATE] = id;
205 psci_ops.migrate = psci_migrate;
206 }
207
208out_put_node:
209 of_node_put(np);
210 return err;
211}
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 894c1e5ed609..113db863f832 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -50,6 +50,7 @@
50#include <asm/tlbflush.h> 50#include <asm/tlbflush.h>
51#include <asm/traps.h> 51#include <asm/traps.h>
52#include <asm/memblock.h> 52#include <asm/memblock.h>
53#include <asm/psci.h>
53 54
54unsigned int processor_id; 55unsigned int processor_id;
55EXPORT_SYMBOL(processor_id); 56EXPORT_SYMBOL(processor_id);
@@ -261,6 +262,8 @@ void __init setup_arch(char **cmdline_p)
261 262
262 unflatten_device_tree(); 263 unflatten_device_tree();
263 264
265 psci_init();
266
264#ifdef CONFIG_SMP 267#ifdef CONFIG_SMP
265 smp_init_cpus(); 268 smp_init_cpus();
266#endif 269#endif