/*
 * Copyright (C) 2015, 2016 ARM Ltd.
 *
 * 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_ARM_KVM_VGIC_VGIC_H
#define __ASM_ARM_KVM_VGIC_VGIC_H

#include <linux/kernel.h>
#include <linux/kvm.h>
#include <linux/irqreturn.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <kvm/iodev.h>

#define VGIC_V3_MAX_CPUS	255
#define VGIC_V2_MAX_CPUS	8
#define VGIC_NR_IRQS_LEGACY     256
#define VGIC_NR_SGIS		16
#define VGIC_NR_PPIS		16
#define VGIC_NR_PRIVATE_IRQS	(VGIC_NR_SGIS + VGIC_NR_PPIS)
#define VGIC_MAX_PRIVATE	(VGIC_NR_PRIVATE_IRQS - 1)
#define VGIC_MAX_SPI		1019
#define VGIC_MAX_RESERVED	1023
#define VGIC_MIN_LPI		8192

enum vgic_type {
	VGIC_V2,		/* Good ol' GICv2 */
	VGIC_V3,		/* New fancy GICv3 */
};

/* same for all guests, as depending only on the _host's_ GIC model */
struct vgic_global {
	/* type of the host GIC */
	enum vgic_type		type;

	/* Physical address of vgic virtual cpu interface */
	phys_addr_t		vcpu_base;

	/* virtual control interface mapping */
	void __iomem		*vctrl_base;

	/* Number of implemented list registers */
	int			nr_lr;

	/* Maintenance IRQ number */
	unsigned int		maint_irq;

	/* maximum number of VCPUs allowed (GICv2 limits us to 8) */
	int			max_gic_vcpus;

	/* Only needed for the legacy KVM_CREATE_IRQCHIP */
	bool			can_emulate_gicv2;
};

extern struct vgic_global kvm_vgic_global_state;

#define VGIC_V2_MAX_LRS		(1 << 6)
#define VGIC_V3_MAX_LRS		16
#define VGIC_V3_LR_INDEX(lr)	(VGIC_V3_MAX_LRS - 1 - lr)

enum vgic_irq_config {
	VGIC_CONFIG_EDGE = 0,
	VGIC_CONFIG_LEVEL
};

struct vgic_irq {
	spinlock_t irq_lock;		/* Protects the content of the struct */
	struct list_head ap_list;

	struct kvm_vcpu *vcpu;		/* SGIs and PPIs: The VCPU
					 * SPIs and LPIs: The VCPU whose ap_list
					 * this is queued on.
					 */

	struct kvm_vcpu *target_vcpu;	/* The VCPU that this interrupt should
					 * be sent to, as a result of the
					 * targets reg (v2) or the
					 * affinity reg (v3).
					 */

	u32 intid;			/* Guest visible INTID */
	bool pending;
	bool line_level;		/* Level only */
	bool soft_pending;		/* Level only */
	bool active;			/* not used for LPIs */
	bool enabled;
	bool hw;			/* Tied to HW IRQ */
	u32 hwintid;			/* HW INTID number */
	union {
		u8 targets;			/* GICv2 target VCPUs mask */
		u32 mpidr;			/* GICv3 target VCPU */
	};
	u8 source;			/* GICv2 SGIs only */
	u8 priority;
	enum vgic_irq_config config;	/* Level or edge */
};

struct vgic_register_region;

struct vgic_io_device {
	gpa_t base_addr;
	struct kvm_vcpu *redist_vcpu;
	const struct vgic_register_region *regions;
	int nr_regions;
	struct kvm_io_device dev;
};

struct vgic_dist {
	bool			in_kernel;
	bool			ready;

	/* vGIC model the kernel emulates for the guest (GICv2 or GICv3) */
	u32			vgic_model;

	int			nr_spis;

	/* TODO: Consider moving to global state */
	/* Virtual control interface mapping */
	void __iomem		*vctrl_base;

	/* base addresses in guest physical address space: */
	gpa_t			vgic_dist_base;		/* distributor */
	union {
		/* either a GICv2 CPU interface */
		gpa_t			vgic_cpu_base;
		/* or a number of GICv3 redistributor regions */
		gpa_t			vgic_redist_base;
	};

	/* distributor enabled */
	bool			enabled;

	struct vgic_irq		*spis;

	struct vgic_io_device	dist_iodev;
	struct vgic_io_device	*redist_iodevs;
};

struct vgic_v2_cpu_if {
	u32		vgic_hcr;
	u32		vgic_vmcr;
	u32		vgic_misr;	/* Saved only */
	u64		vgic_eisr;	/* Saved only */
	u64		vgic_elrsr;	/* Saved only */
	u32		vgic_apr;
	u32		vgic_lr[VGIC_V2_MAX_LRS];
};

struct vgic_v3_cpu_if {
#ifdef CONFIG_KVM_ARM_VGIC_V3
	u32		vgic_hcr;
	u32		vgic_vmcr;
	u32		vgic_sre;	/* Restored only, change ignored */
	u32		vgic_misr;	/* Saved only */
	u32		vgic_eisr;	/* Saved only */
	u32		vgic_elrsr;	/* Saved only */
	u32		vgic_ap0r[4];
	u32		vgic_ap1r[4];
	u64		vgic_lr[VGIC_V3_MAX_LRS];
#endif
};

struct vgic_cpu {
	/* CPU vif control registers for world switch */
	union {
		struct vgic_v2_cpu_if	vgic_v2;
		struct vgic_v3_cpu_if	vgic_v3;
	};

	unsigned int used_lrs;
	struct vgic_irq private_irqs[VGIC_NR_PRIVATE_IRQS];

	spinlock_t ap_list_lock;	/* Protects the ap_list */

	/*
	 * List of IRQs that this VCPU should consider because they are either
	 * Active or Pending (hence the name; AP list), or because they recently
	 * were one of the two and need to be migrated off this list to another
	 * VCPU.
	 */
	struct list_head ap_list_head;

	u64 live_lrs;
};

int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);

int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
			bool level);

int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);

#define irqchip_in_kernel(k)	(!!((k)->arch.vgic.in_kernel))
#define vgic_initialized(k)	(false)
#define vgic_ready(k)		((k)->arch.vgic.ready)
#define vgic_valid_spi(k, i)	(((i) >= VGIC_NR_PRIVATE_IRQS) && \
			((i) < (k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS))

bool kvm_vcpu_has_pending_irqs(struct kvm_vcpu *vcpu);
void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);

#ifdef CONFIG_KVM_ARM_VGIC_V3
void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
#else
static inline void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg)
{
}
#endif

/**
 * kvm_vgic_get_max_vcpus - Get the maximum number of VCPUs allowed by HW
 *
 * The host's GIC naturally limits the maximum amount of VCPUs a guest
 * can use.
 */
static inline int kvm_vgic_get_max_vcpus(void)
{
	return kvm_vgic_global_state.max_gic_vcpus;
}

#endif /* __ASM_ARM_KVM_VGIC_VGIC_H */