u-boot/arch/arm/cpu/armv8/fwcall.c
Alexander Graf e4679489c3 efi_loader: Convert runtime reset from switch to if statements
We currently handle the UEFI runtime reset / power off case handling via
a switch statement. Compilers (gcc in my case) may opt to handle these via
jump tables which they may conveniently put into .rodata which is not part
of the runtime section, so it will be unreachable when executed.

Fix this by just converting the switch statement into an if/else statement.
It produces smaller code that is faster and also correct because we no
longer refer .rodata from efi runtime code.

Reported-by: Andreas Färber <aferber@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-06-14 10:52:14 +02:00

157 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/**
* (C) Copyright 2014, Cavium Inc.
* (C) Copyright 2017, Xilinx Inc.
*
**/
#include <asm-offsets.h>
#include <config.h>
#include <efi_loader.h>
#include <version.h>
#include <asm/macro.h>
#include <asm/psci.h>
#include <asm/system.h>
/*
* Issue the hypervisor call
*
* x0~x7: input arguments
* x0~x3: output arguments
*/
static void __efi_runtime hvc_call(struct pt_regs *args)
{
asm volatile(
"ldr x0, %0\n"
"ldr x1, %1\n"
"ldr x2, %2\n"
"ldr x3, %3\n"
"ldr x4, %4\n"
"ldr x5, %5\n"
"ldr x6, %6\n"
"ldr x7, %7\n"
"hvc #0\n"
"str x0, %0\n"
"str x1, %1\n"
"str x2, %2\n"
"str x3, %3\n"
: "+m" (args->regs[0]), "+m" (args->regs[1]),
"+m" (args->regs[2]), "+m" (args->regs[3])
: "m" (args->regs[4]), "m" (args->regs[5]),
"m" (args->regs[6]), "m" (args->regs[7])
: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
"x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
"x16", "x17");
}
/*
* void smc_call(arg0, arg1...arg7)
*
* issue the secure monitor call
*
* x0~x7: input arguments
* x0~x3: output arguments
*/
void __efi_runtime smc_call(struct pt_regs *args)
{
asm volatile(
"ldr x0, %0\n"
"ldr x1, %1\n"
"ldr x2, %2\n"
"ldr x3, %3\n"
"ldr x4, %4\n"
"ldr x5, %5\n"
"ldr x6, %6\n"
"smc #0\n"
"str x0, %0\n"
"str x1, %1\n"
"str x2, %2\n"
"str x3, %3\n"
: "+m" (args->regs[0]), "+m" (args->regs[1]),
"+m" (args->regs[2]), "+m" (args->regs[3])
: "m" (args->regs[4]), "m" (args->regs[5]),
"m" (args->regs[6])
: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
"x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
"x16", "x17");
}
/*
* 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 __efi_runtime_data bool use_smc_for_psci = true;
void __noreturn __efi_runtime psci_system_reset(void)
{
struct pt_regs regs;
regs.regs[0] = ARM_PSCI_0_2_FN_SYSTEM_RESET;
if (use_smc_for_psci)
smc_call(&regs);
else
hvc_call(&regs);
while (1)
;
}
void __noreturn __efi_runtime 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);
while (1)
;
}
#ifdef CONFIG_CMD_POWEROFF
int do_poweroff(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
puts("poweroff ...\n");
udelay(50000); /* wait 50 ms */
disable_interrupts();
psci_system_off();
/*NOTREACHED*/
return 0;
}
#endif
#ifdef CONFIG_PSCI_RESET
void reset_misc(void)
{
psci_system_reset();
}
#ifdef CONFIG_EFI_LOADER
void __efi_runtime EFIAPI efi_reset_system(
enum efi_reset_type reset_type,
efi_status_t reset_status,
unsigned long data_size, void *reset_data)
{
if (reset_type == EFI_RESET_COLD ||
reset_type == EFI_RESET_WARM ||
reset_type == EFI_RESET_PLATFORM_SPECIFIC) {
psci_system_reset();
} else if (reset_type == EFI_RESET_SHUTDOWN) {
psci_system_off();
}
while (1) { }
}
#endif /* CONFIG_EFI_LOADER */
#endif /* CONFIG_PSCI_RESET */