arch/arm/cpu/armv8/fwcall.c

   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_TEXT 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_TEXT 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_TEXT 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_TEXT 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_TEXT 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 */