/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * Derived from arch/arm/include/kvm_emulate.h
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#ifndef __ARM64_KVM_EMULATE_H__
#define __ARM64_KVM_EMULATE_H__

#include <linux/kvm_host.h>

#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_hyp.h>
#include <asm/ptrace.h>
#include <asm/cputype.h>
#include <asm/virt.h>

#define CURRENT_EL_SP_EL0_VECTOR        0x0
#define CURRENT_EL_SP_ELx_VECTOR        0x200
#define LOWER_EL_AArch64_VECTOR         0x400
#define LOWER_EL_AArch32_VECTOR         0x600

enum exception_type {
        except_type_sync        = 0,
        except_type_irq         = 0x80,
        except_type_fiq         = 0x100,
        except_type_serror      = 0x180,
};

bool kvm_condition_valid32(const struct kvm_vcpu *vcpu);
void kvm_skip_instr32(struct kvm_vcpu *vcpu);

void kvm_inject_undefined(struct kvm_vcpu *vcpu);
void kvm_inject_vabt(struct kvm_vcpu *vcpu);
void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr);
void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr);

static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
{
        return !(vcpu->arch.hcr_el2 & HCR_RW);
}

static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
{
        vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
        if (is_kernel_in_hyp_mode())
                vcpu->arch.hcr_el2 |= HCR_E2H;
        if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN)) {
                /* route synchronous external abort exceptions to EL2 */
                vcpu->arch.hcr_el2 |= HCR_TEA;
                /* trap error record accesses */
                vcpu->arch.hcr_el2 |= HCR_TERR;
        }

        if (cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) {
                vcpu->arch.hcr_el2 |= HCR_FWB;
        } else {
                /*
                 * For non-FWB CPUs, we trap VM ops (HCR_EL2.TVM) until M+C
                 * get set in SCTLR_EL1 such that we can detect when the guest
                 * MMU gets turned on and do the necessary cache maintenance
                 * then.
                 */
                vcpu->arch.hcr_el2 |= HCR_TVM;
        }

        if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features))
                vcpu->arch.hcr_el2 &= ~HCR_RW;

        /*
         * TID3: trap feature register accesses that we virtualise.
         * For now this is conditional, since no AArch32 feature regs
         * are currently virtualised.
         */
        if (!vcpu_el1_is_32bit(vcpu))
                vcpu->arch.hcr_el2 |= HCR_TID3;

        if (cpus_have_const_cap(ARM64_MISMATCHED_CACHE_TYPE) ||
            vcpu_el1_is_32bit(vcpu))
                vcpu->arch.hcr_el2 |= HCR_TID2;

        if (kvm_has_mte(vcpu->kvm))
                vcpu->arch.hcr_el2 |= HCR_ATA;
}

static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
{
        return (unsigned long *)&vcpu->arch.hcr_el2;
}

static inline void vcpu_clear_wfx_traps(struct kvm_vcpu *vcpu)
{
        vcpu->arch.hcr_el2 &= ~HCR_TWE;
        if (atomic_read(&vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count) ||
            vcpu->kvm->arch.vgic.nassgireq)
                vcpu->arch.hcr_el2 &= ~HCR_TWI;
        else
                vcpu->arch.hcr_el2 |= HCR_TWI;
}

static inline void vcpu_set_wfx_traps(struct kvm_vcpu *vcpu)
{
        vcpu->arch.hcr_el2 |= HCR_TWE;
        vcpu->arch.hcr_el2 |= HCR_TWI;
}

static inline void vcpu_ptrauth_enable(struct kvm_vcpu *vcpu)
{
        vcpu->arch.hcr_el2 |= (HCR_API | HCR_APK);
}

static inline void vcpu_ptrauth_disable(struct kvm_vcpu *vcpu)
{
        vcpu->arch.hcr_el2 &= ~(HCR_API | HCR_APK);
}

static inline unsigned long vcpu_get_vsesr(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.vsesr_el2;
}

static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
{
        vcpu->arch.vsesr_el2 = vsesr;
}

static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
        return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
}

static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
{
        return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
}

static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
{
        return !!(*vcpu_cpsr(vcpu) & PSR_MODE32_BIT);
}

static __always_inline bool kvm_condition_valid(const struct kvm_vcpu *vcpu)
{
        if (vcpu_mode_is_32bit(vcpu))
                return kvm_condition_valid32(vcpu);

        return true;
}

static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
{
        *vcpu_cpsr(vcpu) |= PSR_AA32_T_BIT;
}

/*
 * vcpu_get_reg and vcpu_set_reg should always be passed a register number
 * coming from a read of ESR_EL2. Otherwise, it may give the wrong result on
 * AArch32 with banked registers.
 */
static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
                                         u8 reg_num)
{
        return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
}

static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
                                unsigned long val)
{
        if (reg_num != 31)
                vcpu_gp_regs(vcpu)->regs[reg_num] = val;
}

/*
 * The layout of SPSR for an AArch32 state is different when observed from an
 * AArch64 SPSR_ELx or an AArch32 SPSR_*. This function generates the AArch32
 * view given an AArch64 view.
 *
 * In ARM DDI 0487E.a see:
 *
 * - The AArch64 view (SPSR_EL2) in section C5.2.18, page C5-426
 * - The AArch32 view (SPSR_abt) in section G8.2.126, page G8-6256
 * - The AArch32 view (SPSR_und) in section G8.2.132, page G8-6280
 *
 * Which show the following differences:
 *
 * | Bit | AA64 | AA32 | Notes                       |
 * +-----+------+------+-----------------------------|
 * | 24  | DIT  | J    | J is RES0 in ARMv8          |
 * | 21  | SS   | DIT  | SS doesn't exist in AArch32 |
 *
 * ... and all other bits are (currently) common.
 */
static inline unsigned long host_spsr_to_spsr32(unsigned long spsr)
{
        const unsigned long overlap = BIT(24) | BIT(21);
        unsigned long dit = !!(spsr & PSR_AA32_DIT_BIT);

        spsr &= ~overlap;

        spsr |= dit << 21;

        return spsr;
}

static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
{
        u32 mode;

        if (vcpu_mode_is_32bit(vcpu)) {
                mode = *vcpu_cpsr(vcpu) & PSR_AA32_MODE_MASK;
                return mode > PSR_AA32_MODE_USR;
        }

        mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;

        return mode != PSR_MODE_EL0t;
}

static __always_inline u32 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu)
{
        return vcpu->arch.fault.esr_el2;
}

static __always_inline int kvm_vcpu_get_condition(const struct kvm_vcpu *vcpu)
{
        u32 esr = kvm_vcpu_get_esr(vcpu);

        if (esr & ESR_ELx_CV)
                return (esr & ESR_ELx_COND_MASK) >> ESR_ELx_COND_SHIFT;

        return -1;
}

static __always_inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu)
{
        return vcpu->arch.fault.far_el2;
}

static __always_inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu)
{
        return ((phys_addr_t)vcpu->arch.fault.hpfar_el2 & HPFAR_MASK) << 8;
}

static inline u64 kvm_vcpu_get_disr(const struct kvm_vcpu *vcpu)
{
        return vcpu->arch.fault.disr_el1;
}

static inline u32 kvm_vcpu_hvc_get_imm(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_get_esr(vcpu) & ESR_ELx_xVC_IMM_MASK;
}

static __always_inline bool kvm_vcpu_dabt_isvalid(const struct kvm_vcpu *vcpu)
{
        return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_ISV);
}

static inline unsigned long kvm_vcpu_dabt_iss_nisv_sanitized(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_get_esr(vcpu) & (ESR_ELx_CM | ESR_ELx_WNR | ESR_ELx_FSC);
}

static inline bool kvm_vcpu_dabt_issext(const struct kvm_vcpu *vcpu)
{
        return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SSE);
}

static inline bool kvm_vcpu_dabt_issf(const struct kvm_vcpu *vcpu)
{
        return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_SF);
}

static __always_inline int kvm_vcpu_dabt_get_rd(const struct kvm_vcpu *vcpu)
{
        return (kvm_vcpu_get_esr(vcpu) & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT;
}

static __always_inline bool kvm_vcpu_abt_iss1tw(const struct kvm_vcpu *vcpu)
{
        return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_S1PTW);
}

/* Always check for S1PTW *before* using this. */
static __always_inline bool kvm_vcpu_dabt_iswrite(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_get_esr(vcpu) & ESR_ELx_WNR;
}

static inline bool kvm_vcpu_dabt_is_cm(const struct kvm_vcpu *vcpu)
{
        return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_CM);
}

static __always_inline unsigned int kvm_vcpu_dabt_get_as(const struct kvm_vcpu *vcpu)
{
        return 1 << ((kvm_vcpu_get_esr(vcpu) & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT);
}

/* This one is not specific to Data Abort */
static __always_inline bool kvm_vcpu_trap_il_is32bit(const struct kvm_vcpu *vcpu)
{
        return !!(kvm_vcpu_get_esr(vcpu) & ESR_ELx_IL);
}

static __always_inline u8 kvm_vcpu_trap_get_class(const struct kvm_vcpu *vcpu)
{
        return ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
}

static inline bool kvm_vcpu_trap_is_iabt(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_IABT_LOW;
}

static inline bool kvm_vcpu_trap_is_exec_fault(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_trap_is_iabt(vcpu) && !kvm_vcpu_abt_iss1tw(vcpu);
}

static __always_inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC;
}

static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_TYPE;
}

static __always_inline u8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL;
}

static __always_inline bool kvm_vcpu_abt_issea(const struct kvm_vcpu *vcpu)
{
        switch (kvm_vcpu_trap_get_fault(vcpu)) {
        case FSC_SEA:
        case FSC_SEA_TTW0:
        case FSC_SEA_TTW1:
        case FSC_SEA_TTW2:
        case FSC_SEA_TTW3:
        case FSC_SECC:
        case FSC_SECC_TTW0:
        case FSC_SECC_TTW1:
        case FSC_SECC_TTW2:
        case FSC_SECC_TTW3:
                return true;
        default:
                return false;
        }
}

static __always_inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
{
        u32 esr = kvm_vcpu_get_esr(vcpu);
        return ESR_ELx_SYS64_ISS_RT(esr);
}

static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
{
        if (kvm_vcpu_abt_iss1tw(vcpu))
                return true;

        if (kvm_vcpu_trap_is_iabt(vcpu))
                return false;

        return kvm_vcpu_dabt_iswrite(vcpu);
}

static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
{
        return vcpu_read_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
}

static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
{
        if (vcpu_mode_is_32bit(vcpu)) {
                *vcpu_cpsr(vcpu) |= PSR_AA32_E_BIT;
        } else {
                u64 sctlr = vcpu_read_sys_reg(vcpu, SCTLR_EL1);
                sctlr |= (1 << 25);
                vcpu_write_sys_reg(vcpu, sctlr, SCTLR_EL1);
        }
}

static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
{
        if (vcpu_mode_is_32bit(vcpu))
                return !!(*vcpu_cpsr(vcpu) & PSR_AA32_E_BIT);

        return !!(vcpu_read_sys_reg(vcpu, SCTLR_EL1) & (1 << 25));
}

static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
                                                    unsigned long data,
                                                    unsigned int len)
{
        if (kvm_vcpu_is_be(vcpu)) {
                switch (len) {
                case 1:
                        return data & 0xff;
                case 2:
                        return be16_to_cpu(data & 0xffff);
                case 4:
                        return be32_to_cpu(data & 0xffffffff);
                default:
                        return be64_to_cpu(data);
                }
        } else {
                switch (len) {
                case 1:
                        return data & 0xff;
                case 2:
                        return le16_to_cpu(data & 0xffff);
                case 4:
                        return le32_to_cpu(data & 0xffffffff);
                default:
                        return le64_to_cpu(data);
                }
        }

        return data;            /* Leave LE untouched */
}

static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
                                                    unsigned long data,
                                                    unsigned int len)
{
        if (kvm_vcpu_is_be(vcpu)) {
                switch (len) {
                case 1:
                        return data & 0xff;
                case 2:
                        return cpu_to_be16(data & 0xffff);
                case 4:
                        return cpu_to_be32(data & 0xffffffff);
                default:
                        return cpu_to_be64(data);
                }
        } else {
                switch (len) {
                case 1:
                        return data & 0xff;
                case 2:
                        return cpu_to_le16(data & 0xffff);
                case 4:
                        return cpu_to_le32(data & 0xffffffff);
                default:
                        return cpu_to_le64(data);
                }
        }

        return data;            /* Leave LE untouched */
}

static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
{
        vcpu->arch.flags |= KVM_ARM64_INCREMENT_PC;
}

static inline bool vcpu_has_feature(struct kvm_vcpu *vcpu, int feature)
{
        return test_bit(feature, vcpu->arch.features);
}

#endif /* __ARM64_KVM_EMULATE_H__ */