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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 msix_vector;
42};
43
44/* Our device structure */
45struct virtio_pci_device {
46 struct virtio_device vdev;
47 struct pci_dev *pci_dev;
48 struct virtio_pci_legacy_device ldev;
49 struct virtio_pci_modern_device mdev;
50
51 bool is_legacy;
52
53 /* Where to read and clear interrupt */
54 u8 __iomem *isr;
55
56 /* a list of queues so we can dispatch IRQs */
57 spinlock_t lock;
58 struct list_head virtqueues;
59
60 /* array of all queues for house-keeping */
61 struct virtio_pci_vq_info **vqs;
62
63 /* MSI-X support */
64 int msix_enabled;
65 int intx_enabled;
66 bool intx_soft_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/* disable irq handlers */
106void vp_disable_cbs(struct virtio_device *vdev);
107/* enable irq handlers */
108void vp_enable_cbs(struct virtio_device *vdev);
109/* the notify function used when creating a virt queue */
110bool vp_notify(struct virtqueue *vq);
111/* the config->del_vqs() implementation */
112void vp_del_vqs(struct virtio_device *vdev);
113/* the config->find_vqs() implementation */
114int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
115 struct virtqueue *vqs[], vq_callback_t *callbacks[],
116 const char * const names[], const bool *ctx,
117 struct irq_affinity *desc);
118const char *vp_bus_name(struct virtio_device *vdev);
119
120/* Setup the affinity for a virtqueue:
121 * - force the affinity for per vq vector
122 * - OR over all affinities for shared MSI
123 * - ignore the affinity request if we're using INTX
124 */
125int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
126
127const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
128
129#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
130int virtio_pci_legacy_probe(struct virtio_pci_device *);
131void virtio_pci_legacy_remove(struct virtio_pci_device *);
132#else
133static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
134{
135 return -ENODEV;
136}
137static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
138{
139}
140#endif
141int virtio_pci_modern_probe(struct virtio_pci_device *);
142void virtio_pci_modern_remove(struct virtio_pci_device *);
143
144#endif