kernel/arch/arm64/include/asm/virt.h
2024-07-22 17:22:30 +08:00

134 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#ifndef __ASM__VIRT_H
#define __ASM__VIRT_H
/*
* The arm64 hcall implementation uses x0 to specify the hcall
* number. A value less than HVC_STUB_HCALL_NR indicates a special
* hcall, such as set vector. Any other value is handled in a
* hypervisor specific way.
*
* The hypercall is allowed to clobber any of the caller-saved
* registers (x0-x18), so it is advisable to use it through the
* indirection of a function call (as implemented in hyp-stub.S).
*/
/*
* HVC_SET_VECTORS - Set the value of the vbar_el2 register.
*
* @x1: Physical address of the new vector table.
*/
#define HVC_SET_VECTORS 0
/*
* HVC_SOFT_RESTART - CPU soft reset, used by the cpu_soft_restart routine.
*/
#define HVC_SOFT_RESTART 1
/*
* HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs
*/
#define HVC_RESET_VECTORS 2
/*
* HVC_VHE_RESTART - Upgrade the CPU from EL1 to EL2, if possible
*/
#define HVC_VHE_RESTART 3
/* Max number of HYP stub hypercalls */
#define HVC_STUB_HCALL_NR 4
/* Error returned when an invalid stub number is passed into x0 */
#define HVC_STUB_ERR 0xbadca11
#define BOOT_CPU_MODE_EL1 (0xe11)
#define BOOT_CPU_MODE_EL2 (0xe12)
#ifndef __ASSEMBLY__
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/sysreg.h>
#include <asm/cpufeature.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);
void __hyp_reset_vectors(void);
DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
/* Reports the availability of HYP mode */
static inline bool is_hyp_mode_available(void)
{
/*
* If KVM protected mode is initialized, all CPUs must have been booted
* in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
*/
if (IS_ENABLED(CONFIG_KVM) &&
static_branch_likely(&kvm_protected_mode_initialized))
return true;
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)
{
/*
* If KVM protected mode is initialized, all CPUs must have been booted
* in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
*/
if (IS_ENABLED(CONFIG_KVM) &&
static_branch_likely(&kvm_protected_mode_initialized))
return false;
return __boot_cpu_mode[0] != __boot_cpu_mode[1];
}
static inline bool is_kernel_in_hyp_mode(void)
{
return read_sysreg(CurrentEL) == CurrentEL_EL2;
}
static __always_inline bool has_vhe(void)
{
/*
* Code only run in VHE/NVHE hyp context can assume VHE is present or
* absent. Otherwise fall back to caps.
*/
if (is_vhe_hyp_code())
return true;
else if (is_nvhe_hyp_code())
return false;
else
return cpus_have_final_cap(ARM64_HAS_VIRT_HOST_EXTN);
}
static __always_inline bool is_protected_kvm_enabled(void)
{
if (is_vhe_hyp_code())
return false;
else
return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE);
}
#endif /* __ASSEMBLY__ */
#endif /* ! __ASM__VIRT_H */