// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012-2015 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */

#include <hyp/adjust_pc.h>

#include <linux/compiler.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm_host.h>
#include <linux/swab.h>

#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>

static bool __is_be(struct kvm_vcpu *vcpu)
{
        if (vcpu_mode_is_32bit(vcpu))
                return !!(read_sysreg_el2(SYS_SPSR) & PSR_AA32_E_BIT);

        return !!(read_sysreg_el1(SYS_SCTLR) & SCTLR_ELx_EE);
}

/*
 * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the
 *                                   guest.
 *
 * @vcpu: the offending vcpu
 *
 * Returns:
 *  1: GICV access successfully performed
 *  0: Not a GICV access
 * -1: Illegal GICV access successfully performed
 */
int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
{
        struct kvm *kvm = kern_hyp_va(vcpu->kvm);
        struct vgic_dist *vgic = &kvm->arch.vgic;
        phys_addr_t fault_ipa;
        void __iomem *addr;
        int rd;

        /* Build the full address */
        fault_ipa  = kvm_vcpu_get_fault_ipa(vcpu);
        fault_ipa |= FAR_TO_FIPA_OFFSET(kvm_vcpu_get_hfar(vcpu));

        /* If not for GICV, move on */
        if (fault_ipa <  vgic->vgic_cpu_base ||
            fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))
                return 0;

        /* Reject anything but a 32bit access */
        if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) {
                __kvm_skip_instr(vcpu);
                return -1;
        }

        /* Not aligned? Don't bother */
        if (fault_ipa & 3) {
                __kvm_skip_instr(vcpu);
                return -1;
        }

        /* Handle deactivation as a normal exit */
        if ((fault_ipa - vgic->vgic_cpu_base) >= GIC_CPU_DEACTIVATE)
                return 0;

        rd = kvm_vcpu_dabt_get_rd(vcpu);
        addr  = kvm_vgic_global_state.vcpu_hyp_va;
        addr += fault_ipa - vgic->vgic_cpu_base;

        if (kvm_vcpu_dabt_iswrite(vcpu)) {
                u32 data = vcpu_get_reg(vcpu, rd);
                if (__is_be(vcpu)) {
                        /* guest pre-swabbed data, undo this for writel() */
                        data = __kvm_swab32(data);
                }
                writel_relaxed(data, addr);
        } else {
                u32 data = readl_relaxed(addr);
                if (__is_be(vcpu)) {
                        /* guest expects swabbed data */
                        data = __kvm_swab32(data);
                }
                vcpu_set_reg(vcpu, rd, data);
        }

        __kvm_skip_instr(vcpu);

        return 1;
}