[U-Boot] [PATCH v3 1/1] efi_loader: PSCI reset and shutdown
Alexander Graf
agraf at suse.de
Tue Oct 16 12:46:35 UTC 2018
On 15.10.18 18:43, Heinrich Schuchardt wrote:
> 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 poweroff command
> let's move it into the same code module.
>
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
> Travis reporteded no errors in
> https://travis-ci.org/xypron2/u-boot/builds/440843498
> except for two boards with an image size problem.
What exactly triggered the size problem? Where did we grow by how much
to trip them over?
>
> v3:
> update commit message
> v2:
> Use PSCI firmware driver to detect call method.
> Thanks to Sumit for pointing me at dtb parsing as part of
> "psci_probe()
> ---
> arch/arm/cpu/armv7/smccc-call.S | 2 +
> arch/arm/cpu/armv8/Kconfig | 1 +
> arch/arm/cpu/armv8/fwcall.c | 52 ++-----------------
> arch/arm/cpu/armv8/smccc-call.S | 2 +
> drivers/firmware/psci.c | 91 +++++++++++++++++++++++++++------
> include/linux/psci.h | 6 +--
> 6 files changed, 87 insertions(+), 67 deletions(-)
>
> diff --git a/arch/arm/cpu/armv7/smccc-call.S b/arch/arm/cpu/armv7/smccc-call.S
> index 0d8b59eb6b..eae69e36c3 100644
> --- a/arch/arm/cpu/armv7/smccc-call.S
> +++ b/arch/arm/cpu/armv7/smccc-call.S
> @@ -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
> diff --git a/arch/arm/cpu/armv8/Kconfig b/arch/arm/cpu/armv8/Kconfig
> index c8bebabdf6..d643981b73 100644
> --- a/arch/arm/cpu/armv8/Kconfig
> +++ b/arch/arm/cpu/armv8/Kconfig
> @@ -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 && \
> diff --git a/arch/arm/cpu/armv8/fwcall.c b/arch/arm/cpu/armv8/fwcall.c
> index 0ba3dad8cc..9957c2974b 100644
> --- a/arch/arm/cpu/armv8/fwcall.c
> +++ b/arch/arm/cpu/armv8/fwcall.c
> @@ -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 */
> diff --git a/arch/arm/cpu/armv8/smccc-call.S b/arch/arm/cpu/armv8/smccc-call.S
> index 16c9e298b4..86de4b4089 100644
> --- a/arch/arm/cpu/armv8/smccc-call.S
> +++ b/arch/arm/cpu/armv8/smccc-call.S
> @@ -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
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 2cb35f356f..2237668ea6 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -9,31 +9,37 @@
> #include <common.h>
> #include <dm.h>
> #include <dm/lists.h>
> +#include <efi_loader.h>
> #include <linux/libfdt.h>
> #include <linux/arm-smccc.h>
> #include <linux/errno.h>
> #include <linux/printk.h>
> #include <linux/psci.h>
>
> -psci_fn *invoke_psci_fn;
> +#define DRIVER_NAME "psci"
>
> -static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
> - unsigned long arg0, unsigned long arg1,
> - unsigned long arg2)
> -{
> - struct arm_smccc_res res;
> +#define PSCI_METHOD_HVC 1
> +#define PSCI_METHOD_SMC 2
>
> - arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
> - return res.a0;
> -}
> +int __efi_runtime_data psci_method;
>
> -static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
> - unsigned long arg0, unsigned long arg1,
> - unsigned long arg2)
> +unsigned long __efi_runtime invoke_psci_fn
> + (unsigned long function_id, unsigned long arg0,
> + unsigned long arg1, unsigned long arg2)
> {
> struct arm_smccc_res res;
>
> - arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
> + switch (psci_method) {
> + case PSCI_METHOD_SMC:
> + arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
> + break;
> + case PSCI_METHOD_HVC:
> + arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
> + break;
> + default:
> + res.a0 = PSCI_RET_DISABLED;
We will never get here, because probing will fail with neither SMC nor
HVC set.
Also, while I find switch cases more readable, gcc will do funky things
when it sees them, like generate jump tables and forgetting that it can
do constant propagation. I would prefer to stick with the bool based
approach here and just simply do either SMC or HVC.
Alex
> + break;
> + }
> return res.a0;
> }
>
> @@ -67,9 +73,9 @@ static int psci_probe(struct udevice *dev)
> }
>
> if (!strcmp("hvc", method)) {
> - invoke_psci_fn = __invoke_psci_fn_hvc;
> + psci_method = PSCI_METHOD_HVC;
> } else if (!strcmp("smc", method)) {
> - invoke_psci_fn = __invoke_psci_fn_smc;
> + psci_method = PSCI_METHOD_SMC;
> } else {
> pr_warn("invalid \"method\" property: %s\n", method);
> return -EINVAL;
> @@ -78,6 +84,59 @@ static int psci_probe(struct udevice *dev)
> return 0;
> }
>
> +/**
> + * void do_psci_probe() - probe PSCI firmware driver
> + *
> + * Ensure that psci_method is initialized.
> + */
> +static void __maybe_unused do_psci_probe(void)
> +{
> + struct udevice *dev;
> +
> + uclass_get_device_by_name(UCLASS_FIRMWARE, DRIVER_NAME, &dev);
> +}
> +
> +#ifdef CONFIG_EFI_LOADER
> +efi_status_t efi_reset_system_init(void)
> +{
> + do_psci_probe();
> + return EFI_SUCCESS;
> +}
> +
> +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) {
> + invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
> + } else if (reset_type == EFI_RESET_SHUTDOWN) {
> + invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
> + }
> + while (1)
> + ;
> +}
> +#endif /* CONFIG_EFI_LOADER */
> +
> +#ifdef CONFIG_CMD_POWEROFF
> +int do_poweroff(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> +{
> + do_psci_probe();
> +
> + puts("poweroff ...\n");
> + udelay(50000); /* wait 50 ms */
> +
> + disable_interrupts();
> + invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
> + enable_interrupts();
> +
> + log_err("Power off not supported on this platform\n");
> + return CMD_RET_FAILURE;
> +}
> +#endif
> +
> static const struct udevice_id psci_of_match[] = {
> { .compatible = "arm,psci" },
> { .compatible = "arm,psci-0.2" },
> @@ -86,7 +145,7 @@ static const struct udevice_id psci_of_match[] = {
> };
>
> U_BOOT_DRIVER(psci) = {
> - .name = "psci",
> + .name = DRIVER_NAME,
> .id = UCLASS_FIRMWARE,
> .of_match = psci_of_match,
> .bind = psci_bind,
> diff --git a/include/linux/psci.h b/include/linux/psci.h
> index 8d13bd2702..9433df836b 100644
> --- a/include/linux/psci.h
> +++ b/include/linux/psci.h
> @@ -88,10 +88,8 @@
> #define PSCI_RET_DISABLED -8
>
> #ifdef CONFIG_ARM_PSCI_FW
> -typedef unsigned long (psci_fn)(unsigned long, unsigned long,
> - unsigned long, unsigned long);
> -
> -extern psci_fn *invoke_psci_fn;
> +unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
> + unsigned long a2, unsigned long a3);
> #else
> unsigned long invoke_psci_fn(unsigned long a0, unsigned long a1,
> unsigned long a2, unsigned long a3)
>
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