/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
#define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
/*
 * Virtio PCI driver - APIs for common functionality for all device versions
 *
 * This module allows virtio devices to be used over a virtual PCI device.
 * This can be used with QEMU based VMMs like KVM or Xen.
 *
 * Copyright IBM Corp. 2007
 * Copyright Red Hat, Inc. 2014
 *
 * Authors:
 *  Anthony Liguori  <aliguori@us.ibm.com>
 *  Rusty Russell <rusty@rustcorp.com.au>
 *  Michael S. Tsirkin <mst@redhat.com>
 */

#include <linux/module.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_pci.h>
#include <linux/virtio_pci_legacy.h>
#include <linux/virtio_pci_modern.h>
#include <linux/highmem.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>

struct virtio_pci_vq_info {
        /* the actual virtqueue */
        struct virtqueue *vq;

        /* the list node for the virtqueues or slow_virtqueues list */
        struct list_head node;

        /* MSI-X vector (or none) */
        unsigned int msix_vector;
};

struct virtio_pci_admin_vq {
        /* Virtqueue info associated with this admin queue. */
        struct virtio_pci_vq_info *info;
        /* Protects virtqueue access. */
        spinlock_t lock;
        u64 supported_cmds;
        u64 supported_caps;
        u8 max_dev_parts_objects;
        struct ida dev_parts_ida;
        /* Name of the admin queue: avq.$vq_index. */
        char name[10];
        u16 vq_index;
};

/* Our device structure */
struct virtio_pci_device {
        struct virtio_device vdev;
        struct pci_dev *pci_dev;
        union {
                struct virtio_pci_legacy_device ldev;
                struct virtio_pci_modern_device mdev;
        };
        bool is_legacy;

        /* Where to read and clear interrupt */
        u8 __iomem *isr;

        /* Lists of queues and potentially slow path queues
         * so we can dispatch IRQs.
         */
        spinlock_t lock;
        struct list_head virtqueues;
        struct list_head slow_virtqueues;

        /* Array of all virtqueues reported in the
         * PCI common config num_queues field
         */
        struct virtio_pci_vq_info **vqs;

        struct virtio_pci_admin_vq admin_vq;

        /* MSI-X support */
        int msix_enabled;
        int intx_enabled;
        cpumask_var_t *msix_affinity_masks;
        /* Name strings for interrupts. This size should be enough,
         * and I'm too lazy to allocate each name separately. */
        char (*msix_names)[256];
        /* Number of available vectors */
        unsigned int msix_vectors;
        /* Vectors allocated, excluding per-vq vectors if any */
        unsigned int msix_used_vectors;

        /* Whether we have vector per vq */
        bool per_vq_vectors;

        struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
                                      struct virtio_pci_vq_info *info,
                                      unsigned int idx,
                                      void (*callback)(struct virtqueue *vq),
                                      const char *name,
                                      bool ctx,
                                      u16 msix_vec);
        void (*del_vq)(struct virtio_pci_vq_info *info);

        u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
        int (*avq_index)(struct virtio_device *vdev, u16 *index, u16 *num);
};

/* Constants for MSI-X */
/* Use first vector for configuration changes, second and the rest for
 * virtqueues Thus, we need at least 2 vectors for MSI. */
enum {
        VP_MSIX_CONFIG_VECTOR = 0,
        VP_MSIX_VQ_VECTOR = 1,
};

/* Convert a generic virtio device to our structure */
static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
{
        return container_of(vdev, struct virtio_pci_device, vdev);
}

/* wait for pending irq handlers */
void vp_synchronize_vectors(struct virtio_device *vdev);
/* the notify function used when creating a virt queue */
bool vp_notify(struct virtqueue *vq);
/* the config->del_vqs() implementation */
void vp_del_vqs(struct virtio_device *vdev);
/* the config->find_vqs() implementation */
int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
                struct virtqueue *vqs[], struct virtqueue_info vqs_info[],
                struct irq_affinity *desc);
const char *vp_bus_name(struct virtio_device *vdev);

/* Setup the affinity for a virtqueue:
 * - force the affinity for per vq vector
 * - OR over all affinities for shared MSI
 * - ignore the affinity request if we're using INTX
 */
int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);

const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);

#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
int virtio_pci_legacy_probe(struct virtio_pci_device *);
void virtio_pci_legacy_remove(struct virtio_pci_device *);
#else
static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
{
        return -ENODEV;
}
static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
{
}
#endif
int virtio_pci_modern_probe(struct virtio_pci_device *);
void virtio_pci_modern_remove(struct virtio_pci_device *);

struct virtio_device *virtio_pci_vf_get_pf_dev(struct pci_dev *pdev);

#define VIRTIO_LEGACY_ADMIN_CMD_BITMAP \
        (BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO))

#define VIRTIO_DEV_PARTS_ADMIN_CMD_BITMAP \
        (BIT_ULL(VIRTIO_ADMIN_CMD_CAP_ID_LIST_QUERY) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_DRIVER_CAP_SET) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_DEVICE_CAP_GET) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_RESOURCE_OBJ_CREATE) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_RESOURCE_OBJ_DESTROY) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_DEV_PARTS_METADATA_GET) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_DEV_PARTS_GET) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_DEV_PARTS_SET) | \
         BIT_ULL(VIRTIO_ADMIN_CMD_DEV_MODE_SET))

/* Unlike modern drivers which support hardware virtio devices, legacy drivers
 * assume software-based devices: e.g. they don't use proper memory barriers
 * on ARM, use big endian on PPC, etc. X86 drivers are mostly ok though, more
 * or less by chance. For now, only support legacy IO on X86.
 */
#ifdef CONFIG_VIRTIO_PCI_ADMIN_LEGACY
#define VIRTIO_ADMIN_CMD_BITMAP (VIRTIO_LEGACY_ADMIN_CMD_BITMAP | \
                                 VIRTIO_DEV_PARTS_ADMIN_CMD_BITMAP)
#else
#define VIRTIO_ADMIN_CMD_BITMAP VIRTIO_DEV_PARTS_ADMIN_CMD_BITMAP
#endif

bool vp_is_avq(struct virtio_device *vdev, unsigned int index);
void vp_modern_avq_done(struct virtqueue *vq);
int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
                             struct virtio_admin_cmd *cmd);

#endif