alistair23-linux/arch/arm64/include/asm/virt.h
Suzuki K Poulose ac1ad20f9e arm64: vhe: Verify CPU Exception Levels
With a VHE capable CPU, kernel can run at EL2 and is a decided at early
boot. If some of the CPUs didn't start it EL2 or doesn't have VHE, we
could have CPUs running at different exception levels, all in the same
kernel! This patch adds an early check for the secondary CPUs to detect
such situations.

For each non-boot CPU add a sanity check to make sure we don't have
different run levels w.r.t the boot CPU. We save the information on
whether the boot CPU is running in hyp mode or not and ensure the
remaining CPUs match it.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: made boot_cpu_hyp_mode static]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-15 18:06:07 +01:00

76 lines
2.1 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM__VIRT_H
#define __ASM__VIRT_H
#define BOOT_CPU_MODE_EL1 (0xe11)
#define BOOT_CPU_MODE_EL2 (0xe12)
#ifndef __ASSEMBLY__
#include <asm/ptrace.h>
/*
* __boot_cpu_mode records what mode CPUs were booted in.
* A correctly-implemented bootloader must start all CPUs in the same mode:
* In this case, both 32bit halves of __boot_cpu_mode will contain the
* same value (either 0 if booted in EL1, BOOT_CPU_MODE_EL2 if booted in EL2).
*
* Should the bootloader fail to do this, the two values will be different.
* This allows the kernel to flag an error when the secondaries have come up.
*/
extern u32 __boot_cpu_mode[2];
void __hyp_set_vectors(phys_addr_t phys_vector_base);
phys_addr_t __hyp_get_vectors(void);
/* Reports the availability of HYP mode */
static inline bool is_hyp_mode_available(void)
{
return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
}
/* Check if the bootloader has booted CPUs in different modes */
static inline bool is_hyp_mode_mismatched(void)
{
return __boot_cpu_mode[0] != __boot_cpu_mode[1];
}
static inline bool is_kernel_in_hyp_mode(void)
{
u64 el;
asm("mrs %0, CurrentEL" : "=r" (el));
return el == CurrentEL_EL2;
}
#ifdef CONFIG_ARM64_VHE
extern void verify_cpu_run_el(void);
#else
static inline void verify_cpu_run_el(void) {}
#endif
/* The section containing the hypervisor text */
extern char __hyp_text_start[];
extern char __hyp_text_end[];
#endif /* __ASSEMBLY__ */
#endif /* ! __ASM__VIRT_H */