efi_loader: refactor switch to non-secure mode

Refactor the switch from supervisor to hypervisor to a new function called
at the beginning of do_bootefi().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Heinrich Schuchardt 2019-01-08 18:13:06 +01:00 committed by Alexander Graf
parent b4f471f18e
commit f6c6df7ebc
7 changed files with 132 additions and 67 deletions

View File

@ -14,6 +14,7 @@ obj-$(CONFIG_SYS_ARM_MPU) += mpu_v7r.o
ifneq ($(CONFIG_SPL_BUILD),y)
obj-$(CONFIG_EFI_LOADER) += sctlr.o
obj-$(CONFIG_ARMV7_NONSEC) += exception_level.o
endif
ifneq ($(CONFIG_SKIP_LOWLEVEL_INIT),y)

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@ -0,0 +1,56 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Switch to non-secure mode
*
* Copyright (c) 2018 Heinrich Schuchardt
*
* This module contains the ARMv7 specific code required for leaving the
* secure mode before booting an operating system.
*/
#include <common.h>
#include <bootm.h>
#include <asm/armv7.h>
#include <asm/secure.h>
#include <asm/setjmp.h>
/**
* entry_non_secure() - entry point when switching to non-secure mode
*
* When switching to non-secure mode switch_to_non_secure_mode() calls this
* function passing a jump buffer. We use this jump buffer to restore the
* original stack and register state.
*
* @non_secure_jmp: jump buffer for restoring stack and registers
*/
static void entry_non_secure(struct jmp_buf_data *non_secure_jmp)
{
dcache_enable();
debug("Reached non-secure mode\n");
/* Restore stack and registers saved in switch_to_non_secure_mode() */
longjmp(non_secure_jmp, 1);
}
/**
* switch_to_non_secure_mode() - switch to non-secure mode
*
* Operating systems may expect to run in non-secure mode. Here we check if
* we are running in secure mode and switch to non-secure mode if necessary.
*/
void switch_to_non_secure_mode(void)
{
static bool is_nonsec;
struct jmp_buf_data non_secure_jmp;
if (armv7_boot_nonsec() && !is_nonsec) {
if (setjmp(&non_secure_jmp))
return;
dcache_disable(); /* flush cache before switch to HYP */
armv7_init_nonsec();
is_nonsec = true;
secure_ram_addr(_do_nonsec_entry)(entry_non_secure,
(uintptr_t)&non_secure_jmp,
0, 0);
}
}

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@ -14,6 +14,7 @@ ifdef CONFIG_SPL_BUILD
obj-$(CONFIG_ARMV8_SPL_EXCEPTION_VECTORS) += exceptions.o
else
obj-y += exceptions.o
obj-y += exception_level.o
endif
obj-y += cache.o
obj-y += tlb.o

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@ -0,0 +1,55 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Switch to non-secure mode
*
* Copyright (c) 2018 Heinrich Schuchardt
*
* This module contains the ARMv8 specific code required to adjust the exception
* level before booting an operating system.
*/
#include <common.h>
#include <bootm.h>
#include <asm/setjmp.h>
/**
* entry_non_secure() - entry point when switching to non-secure mode
*
* When switching to non-secure mode switch_to_non_secure_mode() calls this
* function passing a jump buffer. We use this jump buffer to restore the
* original stack and register state.
*
* @non_secure_jmp: jump buffer for restoring stack and registers
*/
static void entry_non_secure(struct jmp_buf_data *non_secure_jmp)
{
dcache_enable();
debug("Reached non-secure mode\n");
/* Restore stack and registers saved in switch_to_non_secure_mode() */
longjmp(non_secure_jmp, 1);
}
/**
* switch_to_non_secure_mode() - switch to non-secure mode
*
* Exception level EL3 is meant to be used by the secure monitor only (ARM
* trusted firmware being one embodiment). The operating system shall be
* started at exception level EL2. So here we check the exception level
* and switch it if necessary.
*/
void switch_to_non_secure_mode(void)
{
struct jmp_buf_data non_secure_jmp;
/* On AArch64 we need to make sure we call our payload in < EL3 */
if (current_el() == 3) {
if (setjmp(&non_secure_jmp))
return;
dcache_disable(); /* flush cache before switch to EL2 */
/* Move into EL2 and keep running there */
armv8_switch_to_el2((uintptr_t)&non_secure_jmp, 0, 0, 0,
(uintptr_t)entry_non_secure, ES_TO_AARCH64);
}
}

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@ -5,8 +5,9 @@
* Copyright (c) 2016 Alexander Graf
*/
#include <charset.h>
#include <common.h>
#include <bootm.h>
#include <charset.h>
#include <command.h>
#include <dm.h>
#include <efi_loader.h>
@ -21,11 +22,6 @@
#include <asm-generic/unaligned.h>
#include <linux/linkage.h>
#ifdef CONFIG_ARMV7_NONSEC
#include <asm/armv7.h>
#include <asm/secure.h>
#endif
DECLARE_GLOBAL_DATA_PTR;
static struct efi_device_path *bootefi_image_path;
@ -151,34 +147,6 @@ static efi_status_t efi_do_enter(
return ret;
}
#ifdef CONFIG_ARM64
static efi_status_t efi_run_in_el2(EFIAPI efi_status_t (*entry)(
efi_handle_t image_handle, struct efi_system_table *st),
efi_handle_t image_handle, struct efi_system_table *st)
{
/* Enable caches again */
dcache_enable();
return efi_do_enter(image_handle, st, entry);
}
#endif
#ifdef CONFIG_ARMV7_NONSEC
static bool is_nonsec;
static efi_status_t efi_run_in_hyp(EFIAPI efi_status_t (*entry)(
efi_handle_t image_handle, struct efi_system_table *st),
efi_handle_t image_handle, struct efi_system_table *st)
{
/* Enable caches again */
dcache_enable();
is_nonsec = true;
return efi_do_enter(image_handle, st, entry);
}
#endif
/*
* efi_carve_out_dt_rsv() - Carve out DT reserved memory ranges
*
@ -358,39 +326,6 @@ static efi_status_t do_bootefi_exec(void *efi,
goto err_prepare;
}
#ifdef CONFIG_ARM64
/* On AArch64 we need to make sure we call our payload in < EL3 */
if (current_el() == 3) {
smp_kick_all_cpus();
dcache_disable(); /* flush cache before switch to EL2 */
/* Move into EL2 and keep running there */
armv8_switch_to_el2((ulong)entry,
(ulong)&image_obj->header,
(ulong)&systab, 0, (ulong)efi_run_in_el2,
ES_TO_AARCH64);
/* Should never reach here, efi exits with longjmp */
while (1) { }
}
#endif
#ifdef CONFIG_ARMV7_NONSEC
if (armv7_boot_nonsec() && !is_nonsec) {
dcache_disable(); /* flush cache before switch to HYP */
armv7_init_nonsec();
secure_ram_addr(_do_nonsec_entry)(
efi_run_in_hyp,
(uintptr_t)entry,
(uintptr_t)&image_obj->header,
(uintptr_t)&systab);
/* Should never reach here, efi exits with longjmp */
while (1) { }
}
#endif
ret = efi_do_enter(&image_obj->header, &systab, entry);
err_prepare:
@ -476,6 +411,8 @@ static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
/* Allow unaligned memory access */
allow_unaligned();
switch_to_non_secure_mode();
/* Initialize EFI drivers */
r = efi_init_obj_list();
if (r != EFI_SUCCESS) {

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@ -912,6 +912,16 @@ static const void *boot_get_kernel(cmd_tbl_t *cmdtp, int flag, int argc,
return buf;
}
/**
* switch_to_non_secure_mode() - switch to non-secure mode
*
* This routine is overridden by architectures requiring this feature.
*/
void __weak switch_to_non_secure_mode(void)
{
}
#else /* USE_HOSTCC */
void memmove_wd(void *to, void *from, size_t len, ulong chunksz)

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@ -82,4 +82,9 @@ int bootm_decomp_image(int comp, ulong load, ulong image_start, int type,
*/
void board_quiesce_devices(void);
/**
* switch_to_non_secure_mode() - switch to non-secure mode
*/
void switch_to_non_secure_mode(void);
#endif