mirror of
https://github.com/AsahiLinux/u-boot
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3ee655ed83
Using PSCI you can not only reset the system, you can also shut it down! This patch exposes a function to do exactly that to whatever code wants to make use of it. Signed-off-by: Alexander Graf <agraf@suse.de> Reviewed-by: Simon Glass <sjg@chromium.org>
114 lines
2.2 KiB
C
114 lines
2.2 KiB
C
/**
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* (C) Copyright 2014, Cavium Inc.
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*
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* SPDX-License-Identifier: GPL-2.0+
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**/
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#include <asm-offsets.h>
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#include <config.h>
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#include <version.h>
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#include <asm/macro.h>
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#include <asm/psci.h>
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#include <asm/system.h>
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/*
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* Issue the hypervisor call
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*
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* x0~x7: input arguments
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* x0~x3: output arguments
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*/
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static void hvc_call(struct pt_regs *args)
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{
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asm volatile(
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"ldr x0, %0\n"
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"ldr x1, %1\n"
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"ldr x2, %2\n"
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"ldr x3, %3\n"
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"ldr x4, %4\n"
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"ldr x5, %5\n"
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"ldr x6, %6\n"
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"ldr x7, %7\n"
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"hvc #0\n"
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"str x0, %0\n"
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"str x1, %1\n"
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"str x2, %2\n"
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"str x3, %3\n"
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: "+m" (args->regs[0]), "+m" (args->regs[1]),
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"+m" (args->regs[2]), "+m" (args->regs[3])
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: "m" (args->regs[4]), "m" (args->regs[5]),
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"m" (args->regs[6]), "m" (args->regs[7])
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: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
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"x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
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"x16", "x17");
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}
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/*
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* void smc_call(arg0, arg1...arg7)
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*
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* issue the secure monitor call
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*
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* x0~x7: input arguments
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* x0~x3: output arguments
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*/
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void smc_call(struct pt_regs *args)
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{
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asm volatile(
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"ldr x0, %0\n"
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"ldr x1, %1\n"
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"ldr x2, %2\n"
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"ldr x3, %3\n"
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"ldr x4, %4\n"
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"ldr x5, %5\n"
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"ldr x6, %6\n"
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"smc #0\n"
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"str x0, %0\n"
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"str x1, %1\n"
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"str x2, %2\n"
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"str x3, %3\n"
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: "+m" (args->regs[0]), "+m" (args->regs[1]),
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"+m" (args->regs[2]), "+m" (args->regs[3])
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: "m" (args->regs[4]), "m" (args->regs[5]),
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"m" (args->regs[6])
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: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
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"x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
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"x16", "x17");
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}
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/*
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* For now, all systems we support run at least in EL2 and thus
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* trigger PSCI calls to EL3 using SMC. If anyone ever wants to
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* use PSCI on U-Boot running below a hypervisor, please detect
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* this and set the flag accordingly.
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*/
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static const bool use_smc_for_psci = true;
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void __noreturn psci_system_reset(void)
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{
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struct pt_regs regs;
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regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_RESET;
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if (use_smc_for_psci)
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smc_call(®s);
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else
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hvc_call(®s);
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while (1)
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;
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}
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void __noreturn psci_system_off(void)
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{
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struct pt_regs regs;
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regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_OFF;
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if (use_smc_for_psci)
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smc_call(®s);
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else
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hvc_call(®s);
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while (1)
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;
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}
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