xref: /openbmc/u-boot/arch/arm/cpu/armv8/fwcall.c (revision 6e87ae1c)
1 /**
2  * (C) Copyright 2014, Cavium Inc.
3  * (C) Copyright 2017, Xilinx Inc.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6 **/
7 
8 #include <asm-offsets.h>
9 #include <config.h>
10 #include <efi_loader.h>
11 #include <version.h>
12 #include <asm/macro.h>
13 #include <asm/psci.h>
14 #include <asm/system.h>
15 
16 /*
17  * Issue the hypervisor call
18  *
19  * x0~x7: input arguments
20  * x0~x3: output arguments
21  */
22 static void __efi_runtime hvc_call(struct pt_regs *args)
23 {
24 	asm volatile(
25 		"ldr x0, %0\n"
26 		"ldr x1, %1\n"
27 		"ldr x2, %2\n"
28 		"ldr x3, %3\n"
29 		"ldr x4, %4\n"
30 		"ldr x5, %5\n"
31 		"ldr x6, %6\n"
32 		"ldr x7, %7\n"
33 		"hvc	#0\n"
34 		"str x0, %0\n"
35 		"str x1, %1\n"
36 		"str x2, %2\n"
37 		"str x3, %3\n"
38 		: "+m" (args->regs[0]), "+m" (args->regs[1]),
39 		  "+m" (args->regs[2]), "+m" (args->regs[3])
40 		: "m" (args->regs[4]), "m" (args->regs[5]),
41 		  "m" (args->regs[6]), "m" (args->regs[7])
42 		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
43 		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
44 		  "x16", "x17");
45 }
46 
47 /*
48  * void smc_call(arg0, arg1...arg7)
49  *
50  * issue the secure monitor call
51  *
52  * x0~x7: input arguments
53  * x0~x3: output arguments
54  */
55 
56 void __efi_runtime smc_call(struct pt_regs *args)
57 {
58 	asm volatile(
59 		"ldr x0, %0\n"
60 		"ldr x1, %1\n"
61 		"ldr x2, %2\n"
62 		"ldr x3, %3\n"
63 		"ldr x4, %4\n"
64 		"ldr x5, %5\n"
65 		"ldr x6, %6\n"
66 		"smc	#0\n"
67 		"str x0, %0\n"
68 		"str x1, %1\n"
69 		"str x2, %2\n"
70 		"str x3, %3\n"
71 		: "+m" (args->regs[0]), "+m" (args->regs[1]),
72 		  "+m" (args->regs[2]), "+m" (args->regs[3])
73 		: "m" (args->regs[4]), "m" (args->regs[5]),
74 		  "m" (args->regs[6])
75 		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
76 		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
77 		  "x16", "x17");
78 }
79 
80 /*
81  * For now, all systems we support run at least in EL2 and thus
82  * trigger PSCI calls to EL3 using SMC. If anyone ever wants to
83  * use PSCI on U-Boot running below a hypervisor, please detect
84  * this and set the flag accordingly.
85  */
86 static const __efi_runtime_data bool use_smc_for_psci = true;
87 
88 void __noreturn __efi_runtime psci_system_reset(void)
89 {
90 	struct pt_regs regs;
91 
92 	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_RESET;
93 
94 	if (use_smc_for_psci)
95 		smc_call(&regs);
96 	else
97 		hvc_call(&regs);
98 
99 	while (1)
100 		;
101 }
102 
103 void __noreturn __efi_runtime psci_system_off(void)
104 {
105 	struct pt_regs regs;
106 
107 	regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_OFF;
108 
109 	if (use_smc_for_psci)
110 		smc_call(&regs);
111 	else
112 		hvc_call(&regs);
113 
114 	while (1)
115 		;
116 }
117 
118 #ifdef CONFIG_CMD_POWEROFF
119 int do_poweroff(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
120 {
121 	puts("poweroff ...\n");
122 
123 	udelay(50000); /* wait 50 ms */
124 
125 	disable_interrupts();
126 
127 	psci_system_off();
128 
129 	/*NOTREACHED*/
130 	return 0;
131 }
132 #endif
133 
134 #ifdef CONFIG_PSCI_RESET
135 void reset_misc(void)
136 {
137 	psci_system_reset();
138 }
139 
140 #ifdef CONFIG_EFI_LOADER
141 void __efi_runtime EFIAPI efi_reset_system(
142 			enum efi_reset_type reset_type,
143 			efi_status_t reset_status,
144 			unsigned long data_size, void *reset_data)
145 {
146 	switch (reset_type) {
147 	case EFI_RESET_COLD:
148 	case EFI_RESET_WARM:
149 		psci_system_reset();
150 		break;
151 	case EFI_RESET_SHUTDOWN:
152 		psci_system_off();
153 		break;
154 	}
155 
156 	while (1) { }
157 }
158 #endif /* CONFIG_EFI_LOADER */
159 #endif /* CONFIG_PSCI_RESET */
160