efi_loader: PSCI reset and shutdown

[oweals/u-boot.git] / arch / arm / cpu / armv8 / fwcall.c

diff --git a/arch/arm/cpu/armv8/fwcall.c b/arch/arm/cpu/armv8/fwcall.c
index 079e250cbe995d4f09de60f394e3a3d73e7492bf..9957c2974bc09134207ad0252052e5aabe55688e 100644 (file)
--- a/arch/arm/cpu/armv8/fwcall.c
+++ b/arch/arm/cpu/armv8/fwcall.c
@@ -1,7 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0+
 /**
  * (C) Copyright 2014, Cavium Inc.
+ * (C) Copyright 2017, Xilinx Inc.
  *
- * SPDX-License-Identifier:    GPL-2.0+
 **/
 
 #include <asm-offsets.h>
@@ -17,7 +18,7 @@
  * x0~x7: input arguments
  * x0~x3: output arguments
  */
-void hvc_call(struct pt_regs *args)
+static void hvc_call(struct pt_regs *args)
 {
        asm volatile(
                "ldr x0, %0\n"
@@ -75,13 +76,36 @@ void smc_call(struct pt_regs *args)
                  "x16", "x17");
 }
 
-void __noreturn psci_system_reset(bool conduit_smc)
+/*
+ * 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 (conduit_smc)
+       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);