1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2#ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
  3#define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
  4/*
  5 * Virtio PCI driver - APIs for common functionality for all device versions
  6 *
  7 * This module allows virtio devices to be used over a virtual PCI device.
  8 * This can be used with QEMU based VMMs like KVM or Xen.
  9 *
 10 * Copyright IBM Corp. 2007
 11 * Copyright Red Hat, Inc. 2014
 12 *
 13 * Authors:
 14 *  Anthony Liguori  <aliguori@us.ibm.com>
 15 *  Rusty Russell <rusty@rustcorp.com.au>
 16 *  Michael S. Tsirkin <mst@redhat.com>
 17 */
 18
 19#include <linux/module.h>
 20#include <linux/list.h>
 21#include <linux/pci.h>
 22#include <linux/slab.h>
 23#include <linux/interrupt.h>
 24#include <linux/virtio.h>
 25#include <linux/virtio_config.h>
 26#include <linux/virtio_ring.h>
 27#include <linux/virtio_pci.h>
 28#include <linux/virtio_pci_modern.h>
 29#include <linux/highmem.h>
 30#include <linux/spinlock.h>
 31
 32struct virtio_pci_vq_info {
 33	/* the actual virtqueue */
 34	struct virtqueue *vq;
 35
 36	/* the list node for the virtqueues list */
 37	struct list_head node;
 38
 39	/* MSI-X vector (or none) */
 40	unsigned msix_vector;
 41};
 42
 43/* Our device structure */
 44struct virtio_pci_device {
 45	struct virtio_device vdev;
 46	struct pci_dev *pci_dev;
 47	struct virtio_pci_modern_device mdev;
 48
 49	/* In legacy mode, these two point to within ->legacy. */
 50	/* Where to read and clear interrupt */
 51	u8 __iomem *isr;
 52
 53	/* Legacy only field */
 54	/* the IO mapping for the PCI config space */
 55	void __iomem *ioaddr;
 56
 57	/* a list of queues so we can dispatch IRQs */
 58	spinlock_t lock;
 59	struct list_head virtqueues;
 60
 61	/* array of all queues for house-keeping */
 62	struct virtio_pci_vq_info **vqs;
 63
 64	/* MSI-X support */
 65	int msix_enabled;
 66	int intx_enabled;
 67	cpumask_var_t *msix_affinity_masks;
 68	/* Name strings for interrupts. This size should be enough,
 69	 * and I'm too lazy to allocate each name separately. */
 70	char (*msix_names)[256];
 71	/* Number of available vectors */
 72	unsigned msix_vectors;
 73	/* Vectors allocated, excluding per-vq vectors if any */
 74	unsigned msix_used_vectors;
 75
 76	/* Whether we have vector per vq */
 77	bool per_vq_vectors;
 78
 79	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
 80				      struct virtio_pci_vq_info *info,
 81				      unsigned idx,
 82				      void (*callback)(struct virtqueue *vq),
 83				      const char *name,
 84				      bool ctx,
 85				      u16 msix_vec);
 86	void (*del_vq)(struct virtio_pci_vq_info *info);
 87
 88	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 89};
 90
 91/* Constants for MSI-X */
 92/* Use first vector for configuration changes, second and the rest for
 93 * virtqueues Thus, we need at least 2 vectors for MSI. */
 94enum {
 95	VP_MSIX_CONFIG_VECTOR = 0,
 96	VP_MSIX_VQ_VECTOR = 1,
 97};
 98
 99/* Convert a generic virtio device to our structure */
100static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
101{
102	return container_of(vdev, struct virtio_pci_device, vdev);
103}
104
105/* wait for pending irq handlers */
106void vp_synchronize_vectors(struct virtio_device *vdev);
107/* the notify function used when creating a virt queue */
108bool vp_notify(struct virtqueue *vq);
109/* the config->del_vqs() implementation */
110void vp_del_vqs(struct virtio_device *vdev);
111/* the config->find_vqs() implementation */
112int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
113		struct virtqueue *vqs[], vq_callback_t *callbacks[],
114		const char * const names[], const bool *ctx,
115		struct irq_affinity *desc);
116const char *vp_bus_name(struct virtio_device *vdev);
117
118/* Setup the affinity for a virtqueue:
119 * - force the affinity for per vq vector
120 * - OR over all affinities for shared MSI
121 * - ignore the affinity request if we're using INTX
122 */
123int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
124
125const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
126
127#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
128int virtio_pci_legacy_probe(struct virtio_pci_device *);
129void virtio_pci_legacy_remove(struct virtio_pci_device *);
130#else
131static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
132{
133	return -ENODEV;
134}
135static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
136{
137}
138#endif
139int virtio_pci_modern_probe(struct virtio_pci_device *);
140void virtio_pci_modern_remove(struct virtio_pci_device *);
141
142#endif