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_legacy.h>
29#include <linux/virtio_pci_modern.h>
30#include <linux/highmem.h>
31#include <linux/spinlock.h>
32
33struct virtio_pci_vq_info {
34	/* the actual virtqueue */
35	struct virtqueue *vq;
36
37	/* the list node for the virtqueues list */
38	struct list_head node;
39
40	/* MSI-X vector (or none) */
41	unsigned int msix_vector;
42};
43
44/* Our device structure */
45struct virtio_pci_device {
46	struct virtio_device vdev;
47	struct pci_dev *pci_dev;
48	union {
49		struct virtio_pci_legacy_device ldev;
50		struct virtio_pci_modern_device mdev;
51	};
52	bool is_legacy;
53
54	/* Where to read and clear interrupt */
55	u8 __iomem *isr;
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 int msix_vectors;
73	/* Vectors allocated, excluding per-vq vectors if any */
74	unsigned int 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 int 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 int 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
143