xref: /openbmc/u-boot/arch/arm/cpu/armv8/fwcall.c (revision 274bced8)
1 /**
2  * (C) Copyright 2014, Cavium Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5 **/
6 
7 #include <asm-offsets.h>
8 #include <config.h>
9 #include <efi_loader.h>
10 #include <version.h>
11 #include <asm/macro.h>
12 #include <asm/psci.h>
13 #include <asm/system.h>
14 
15 /*
16  * Issue the hypervisor call
17  *
18  * x0~x7: input arguments
19  * x0~x3: output arguments
20  */
21 static void __efi_runtime hvc_call(struct pt_regs *args)
22 {
23 	asm volatile(
24 		"ldr x0, %0\n"
25 		"ldr x1, %1\n"
26 		"ldr x2, %2\n"
27 		"ldr x3, %3\n"
28 		"ldr x4, %4\n"
29 		"ldr x5, %5\n"
30 		"ldr x6, %6\n"
31 		"ldr x7, %7\n"
32 		"hvc	#0\n"
33 		"str x0, %0\n"
34 		"str x1, %1\n"
35 		"str x2, %2\n"
36 		"str x3, %3\n"
37 		: "+m" (args->regs[0]), "+m" (args->regs[1]),
38 		  "+m" (args->regs[2]), "+m" (args->regs[3])
39 		: "m" (args->regs[4]), "m" (args->regs[5]),
40 		  "m" (args->regs[6]), "m" (args->regs[7])
41 		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
42 		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
43 		  "x16", "x17");
44 }
45 
46 /*
47  * void smc_call(arg0, arg1...arg7)
48  *
49  * issue the secure monitor call
50  *
51  * x0~x7: input arguments
52  * x0~x3: output arguments
53  */
54 
55 void __efi_runtime smc_call(struct pt_regs *args)
56 {
57 	asm volatile(
58 		"ldr x0, %0\n"
59 		"ldr x1, %1\n"
60 		"ldr x2, %2\n"
61 		"ldr x3, %3\n"
62 		"ldr x4, %4\n"
63 		"ldr x5, %5\n"
64 		"ldr x6, %6\n"
65 		"smc	#0\n"
66 		"str x0, %0\n"
67 		"str x1, %1\n"
68 		"str x2, %2\n"
69 		"str x3, %3\n"
70 		: "+m" (args->regs[0]), "+m" (args->regs[1]),
71 		  "+m" (args->regs[2]), "+m" (args->regs[3])
72 		: "m" (args->regs[4]), "m" (args->regs[5]),
73 		  "m" (args->regs[6])
74 		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
75 		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
76 		  "x16", "x17");
77 }
78 
79 /*
80  * For now, all systems we support run at least in EL2 and thus
81  * trigger PSCI calls to EL3 using SMC. If anyone ever wants to
82  * use PSCI on U-Boot running below a hypervisor, please detect
83  * this and set the flag accordingly.
84  */
85 static const __efi_runtime_data bool use_smc_for_psci = true;
86 
87 void __noreturn __efi_runtime psci_system_reset(void)
88 {
89 	struct pt_regs regs;
90 
91 	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_RESET;
92 
93 	if (use_smc_for_psci)
94 		smc_call(&regs);
95 	else
96 		hvc_call(&regs);
97 
98 	while (1)
99 		;
100 }
101 
102 void __noreturn __efi_runtime psci_system_off(void)
103 {
104 	struct pt_regs regs;
105 
106 	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_OFF;
107 
108 	if (use_smc_for_psci)
109 		smc_call(&regs);
110 	else
111 		hvc_call(&regs);
112 
113 	while (1)
114 		;
115 }
116 
117 #ifdef CONFIG_PSCI_RESET
118 void reset_misc(void)
119 {
120 	psci_system_reset();
121 }
122 
123 #ifdef CONFIG_EFI_LOADER
124 void __efi_runtime EFIAPI efi_reset_system(
125 			enum efi_reset_type reset_type,
126 			efi_status_t reset_status,
127 			unsigned long data_size, void *reset_data)
128 {
129 	switch (reset_type) {
130 	case EFI_RESET_COLD:
131 	case EFI_RESET_WARM:
132 		psci_system_reset();
133 		break;
134 	case EFI_RESET_SHUTDOWN:
135 		psci_system_off();
136 		break;
137 	}
138 
139 	while (1) { }
140 }
141 #endif /* CONFIG_EFI_LOADER */
142 #endif /* CONFIG_PSCI_RESET */
143