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efi_loader: PSCI reset and shutdown

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When an operating system started via bootefi tries to reset or power off
this is done by calling the EFI runtime ResetSystem(). On most ARMv8 system
the actual reset relies on PSCI. Depending on whether the PSCI firmware
resides the hypervisor (EL2) or in the secure monitor (EL3) either an HVC
or an SMC command has to be issued.

The current implementation always uses SMC. This results in crashes on
systems where the PSCI firmware is implemented in the hypervisor, e.g.
qemu-arm64_defconfig.

The logic to decide which call is needed based on the device tree is
already implemented in the PSCI firmware driver. During the EFI runtime
the device driver model is not available. But we can minimize code
duplication by merging the EFI runtime reset and poweroff code with
the PSCI firmware driver.

As the same HVC/SMC problem is also evident for the ARMv8 do_poweroff
and reset_misc routines let's move them into the same code module.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Heinrich Schuchardt
2018-10-18 12:29:40 +02:00
committed by Alexander Graf
parent eb3bc8bb17
commit 81ea00838c
6 changed files with 98 additions and 69 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arm/cpu/armv7/smccc-call.S
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@@ -7,6 +7,8 @@
#include <asm/opcodes-sec.h>
#include <asm/opcodes-virt.h>
.section .text.efi_runtime
#define UNWIND(x...)
/*
* Wrap c macros in asm macros to delay expansion until after the

1
arch/arm/cpu/armv8/Kconfig
View File

@@ -96,6 +96,7 @@ endmenu
config PSCI_RESET
bool "Use PSCI for reset and shutdown"
default y
select ARM_SMCCC if OF_CONTROL
depends on !ARCH_EXYNOS7 && !ARCH_BCM283X && \
!TARGET_LS2080A_SIMU && !TARGET_LS2080AQDS && \
!TARGET_LS2080ARDB && !TARGET_LS2080A_EMU && \

52
arch/arm/cpu/armv8/fwcall.c
View File

@@ -7,7 +7,6 @@
#include <asm-offsets.h>
#include <config.h>
#include <efi_loader.h>
#include <version.h>
#include <asm/macro.h>
#include <asm/psci.h>
@@ -19,7 +18,7 @@
* x0~x7: input arguments
* x0~x3: output arguments
*/
static void __efi_runtime hvc_call(struct pt_regs *args)
static void hvc_call(struct pt_regs *args)
{
asm volatile(
"ldr x0, %0\n"
@@ -53,7 +52,7 @@ static void __efi_runtime hvc_call(struct pt_regs *args)
* x0~x3: output arguments
*/
void __efi_runtime smc_call(struct pt_regs *args)
void smc_call(struct pt_regs *args)
{
asm volatile(
"ldr x0, %0\n"
@@ -83,9 +82,9 @@ void __efi_runtime smc_call(struct pt_regs *args)
* 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;
static const bool use_smc_for_psci = true;
void __noreturn __efi_runtime psci_system_reset(void)
void __noreturn psci_system_reset(void)
{
struct pt_regs regs;
@@ -100,7 +99,7 @@ void __noreturn __efi_runtime psci_system_reset(void)
;
}
void __noreturn __efi_runtime psci_system_off(void)
void __noreturn psci_system_off(void)
{
struct pt_regs regs;
@@ -114,44 +113,3 @@ void __noreturn __efi_runtime psci_system_off(void)
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 */

2
arch/arm/cpu/armv8/smccc-call.S
View File

@@ -6,6 +6,8 @@
#include <linux/arm-smccc.h>
#include <generated/asm-offsets.h>
.section .text.efi_runtime
.macro SMCCC instr
.cfi_startproc
\instr #0