/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#ifndef _VIRTIO_PCI_H_
#define _VIRTIO_PCI_H_

#include <stdint.h>
#include <stdbool.h>

#include <rte_pci.h>
#include <rte_bus_pci.h>
#include <ethdev_driver.h>

#include "virtio.h"

struct virtqueue;
struct virtnet_ctl;

/* VirtIO PCI vendor/device ID. */
#define VIRTIO_PCI_VENDORID     0x1AF4
#define VIRTIO_PCI_LEGACY_DEVICEID_NET 0x1000
#define VIRTIO_PCI_MODERN_DEVICEID_NET 0x1041

/* VirtIO ABI version, this must match exactly. */
#define VIRTIO_PCI_ABI_VERSION 0

/*
 * VirtIO Header, located in BAR 0.
 */
#define VIRTIO_PCI_HOST_FEATURES  0  /* host's supported features (32bit, RO)*/
#define VIRTIO_PCI_GUEST_FEATURES 4  /* guest's supported features (32, RW) */
#define VIRTIO_PCI_QUEUE_PFN      8  /* physical address of VQ (32, RW) */
#define VIRTIO_PCI_QUEUE_NUM      12 /* number of ring entries (16, RO) */
#define VIRTIO_PCI_QUEUE_SEL      14 /* current VQ selection (16, RW) */
#define VIRTIO_PCI_QUEUE_NOTIFY   16 /* notify host regarding VQ (16, RW) */
#define VIRTIO_PCI_STATUS         18 /* device status register (8, RW) */
#define VIRTIO_PCI_ISR		  19 /* interrupt status register, reading
				      * also clears the register (8, RO) */
/* Only if MSIX is enabled: */
#define VIRTIO_MSI_CONFIG_VECTOR  20 /* configuration change vector (16, RW) */
#define VIRTIO_MSI_QUEUE_VECTOR	  22 /* vector for selected VQ notifications
				      (16, RW) */

/* Common configuration */
#define VIRTIO_PCI_CAP_COMMON_CFG	1
/* Notifications */
#define VIRTIO_PCI_CAP_NOTIFY_CFG	2
/* ISR Status */
#define VIRTIO_PCI_CAP_ISR_CFG		3
/* Device specific configuration */
#define VIRTIO_PCI_CAP_DEVICE_CFG	4
/* PCI configuration access */
#define VIRTIO_PCI_CAP_PCI_CFG		5

/* This is the PCI capability header: */
struct virtio_pci_cap {
	uint8_t cap_vndr;		/* Generic PCI field: PCI_CAP_ID_VNDR */
	uint8_t cap_next;		/* Generic PCI field: next ptr. */
	uint8_t cap_len;		/* Generic PCI field: capability length */
	uint8_t cfg_type;		/* Identifies the structure. */
	uint8_t bar;			/* Where to find it. */
	uint8_t padding[3];		/* Pad to full dword. */
	uint32_t offset;		/* Offset within bar. */
	uint32_t length;		/* Length of the structure, in bytes. */
};

struct virtio_pci_notify_cap {
	struct virtio_pci_cap cap;
	uint32_t notify_off_multiplier;	/* Multiplier for queue_notify_off. */
};

/* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
struct virtio_pci_common_cfg {
	/* About the whole device. */
	uint32_t device_feature_select;	/* read-write */
	uint32_t device_feature;	/* read-only */
	uint32_t guest_feature_select;	/* read-write */
	uint32_t guest_feature;		/* read-write */
	uint16_t msix_config;		/* read-write */
	uint16_t num_queues;		/* read-only */
	uint8_t device_status;		/* read-write */
	uint8_t config_generation;	/* read-only */

	/* About a specific virtqueue. */
	uint16_t queue_select;		/* read-write */
	uint16_t queue_size;		/* read-write, power of 2. */
	uint16_t queue_msix_vector;	/* read-write */
	uint16_t queue_enable;		/* read-write */
	uint16_t queue_notify_off;	/* read-only */
	uint32_t queue_desc_lo;		/* read-write */
	uint32_t queue_desc_hi;		/* read-write */
	uint32_t queue_avail_lo;	/* read-write */
	uint32_t queue_avail_hi;	/* read-write */
	uint32_t queue_used_lo;		/* read-write */
	uint32_t queue_used_hi;		/* read-write */
};

enum virtio_msix_status {
	VIRTIO_MSIX_NONE = 0,
	VIRTIO_MSIX_DISABLED = 1,
	VIRTIO_MSIX_ENABLED = 2
};

struct virtio_pci_dev {
	struct virtio_hw hw;
	struct virtio_pci_common_cfg *common_cfg;
	struct virtio_net_config *dev_cfg;
	enum virtio_msix_status msix_status;
	uint8_t *isr;
	uint16_t *notify_base;
	uint32_t notify_off_multiplier;
	bool modern;
};

#define virtio_pci_get_dev(hwp) container_of(hwp, struct virtio_pci_dev, hw)

struct virtio_pci_internal {
	struct rte_pci_ioport io;
	struct rte_pci_device *dev;
};

extern struct virtio_pci_internal virtio_pci_internal[RTE_MAX_ETHPORTS];

#define VTPCI_IO(hw) (&virtio_pci_internal[(hw)->port_id].io)
#define VTPCI_DEV(hw) (virtio_pci_internal[(hw)->port_id].dev)


/*
 * How many bits to shift physical queue address written to QUEUE_PFN.
 * 12 is historical, and due to x86 page size.
 */
#define VIRTIO_PCI_QUEUE_ADDR_SHIFT 12

/*
 * Function declaration from virtio_pci.c
 */
int vtpci_init(struct rte_pci_device *pci_dev, struct virtio_pci_dev *dev);
void vtpci_legacy_ioport_unmap(struct virtio_hw *hw);
int vtpci_legacy_ioport_map(struct virtio_hw *hw);

extern const struct virtio_ops legacy_ops;
extern const struct virtio_ops modern_ops;

#endif /* _VIRTIO_PCI_H_ */