arch/arm/cpu/armv8/fwcall.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

// SPDX-License-Identifier: GPL-2.0+
/**
 * (C) Copyright 2014, Cavium Inc.
 * (C) Copyright 2017, Xilinx Inc.
 *
**/

#include <asm-offsets.h>
#include <config.h>
#include <version.h>
#include <asm/macro.h>
#include <asm/psci.h>
#include <asm/system.h>

/*
 * Issue the hypervisor call
 *
 * x0~x7: input arguments
 * x0~x3: output arguments
 */
static void hvc_call(struct pt_regs *args)
{
	asm volatile(
		"ldr x0, %0\n"
		"ldr x1, %1\n"
		"ldr x2, %2\n"
		"ldr x3, %3\n"
		"ldr x4, %4\n"
		"ldr x5, %5\n"
		"ldr x6, %6\n"
		"hvc	#0\n"
		"str x0, %0\n"
		"str x1, %1\n"
		"str x2, %2\n"
		"str x3, %3\n"
		: "+m" (args->regs[0]), "+m" (args->regs[1]),
		  "+m" (args->regs[2]), "+m" (args->regs[3])
		: "m" (args->regs[4]), "m" (args->regs[5]),
		  "m" (args->regs[6])
		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
		  "x16", "x17");
}

/*
 * void smc_call(arg0, arg1...arg7)
 *
 * issue the secure monitor call
 *
 * x0~x7: input arguments
 * x0~x3: output arguments
 */

void smc_call(struct pt_regs *args)
{
	asm volatile(
		"ldr x0, %0\n"
		"ldr x1, %1\n"
		"ldr x2, %2\n"
		"ldr x3, %3\n"
		"ldr x4, %4\n"
		"ldr x5, %5\n"
		"ldr x6, %6\n"
		"smc	#0\n"
		"str x0, %0\n"
		"str x1, %1\n"
		"str x2, %2\n"
		"str x3, %3\n"
		: "+m" (args->regs[0]), "+m" (args->regs[1]),
		  "+m" (args->regs[2]), "+m" (args->regs[3])
		: "m" (args->regs[4]), "m" (args->regs[5]),
		  "m" (args->regs[6])
		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
		  "x16", "x17");
}

/*
 * For now, all systems we support run at least in EL2 and thus
 * trigger PSCI calls to EL3 using SMC. If anyone ever wants to
 * use PSCI on U-Boot running below a hypervisor, please detect
 * this and set the flag accordingly.
 */
static const bool use_smc_for_psci = true;

void __noreturn psci_system_reset(void)
{
	struct pt_regs regs;

	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_RESET;

	if (use_smc_for_psci)
		smc_call(&regs);
	else
		hvc_call(&regs);

	while (1)
		;
}

void __noreturn psci_system_reset2(u32 reset_level, u32 cookie)
{
	struct pt_regs regs;

	regs.regs[0] = ARM_PSCI_0_2_FN64_SYSTEM_RESET2;
	regs.regs[1] = PSCI_RESET2_TYPE_VENDOR | reset_level;
	regs.regs[2] = cookie;
	if (use_smc_for_psci)
		smc_call(&regs);
	else
		hvc_call(&regs);

	while (1)
		;
}

void __noreturn psci_system_off(void)
{
	struct pt_regs regs;

	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_OFF;

	if (use_smc_for_psci)
		smc_call(&regs);
	else
		hvc_call(&regs);

	while (1)
		;
}