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
33 struct 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 */
45 struct 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 cpumask_var_t *msix_affinity_masks;
67 /* Name strings for interrupts. This size should be enough,
68 * and I'm too lazy to allocate each name separately. */
69 char (*msix_names)[256];
70 /* Number of available vectors */
71 unsigned int msix_vectors;
72 /* Vectors allocated, excluding per-vq vectors if any */
73 unsigned int msix_used_vectors;
74
75 /* Whether we have vector per vq */
76 bool per_vq_vectors;
77
78 struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
79 struct virtio_pci_vq_info *info,
80 unsigned int idx,
81 void (*callback)(struct virtqueue *vq),
82 const char *name,
83 bool ctx,
84 u16 msix_vec);
85 void (*del_vq)(struct virtio_pci_vq_info *info);
86
87 u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
88 };
89
90 /* Constants for MSI-X */
91 /* Use first vector for configuration changes, second and the rest for
92 * virtqueues Thus, we need at least 2 vectors for MSI. */
93 enum {
94 VP_MSIX_CONFIG_VECTOR = 0,
95 VP_MSIX_VQ_VECTOR = 1,
96 };
97
98 /* Convert a generic virtio device to our structure */
to_vp_device(struct virtio_device * vdev)99 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
100 {
101 return container_of(vdev, struct virtio_pci_device, vdev);
102 }
103
104 /* wait for pending irq handlers */
105 void vp_synchronize_vectors(struct virtio_device *vdev);
106 /* the notify function used when creating a virt queue */
107 bool vp_notify(struct virtqueue *vq);
108 /* the config->del_vqs() implementation */
109 void vp_del_vqs(struct virtio_device *vdev);
110 /* the config->find_vqs() implementation */
111 int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
112 struct virtqueue *vqs[], vq_callback_t *callbacks[],
113 const char * const names[], const bool *ctx,
114 struct irq_affinity *desc);
115 const char *vp_bus_name(struct virtio_device *vdev);
116
117 /* Setup the affinity for a virtqueue:
118 * - force the affinity for per vq vector
119 * - OR over all affinities for shared MSI
120 * - ignore the affinity request if we're using INTX
121 */
122 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
123
124 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
125
126 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
127 int virtio_pci_legacy_probe(struct virtio_pci_device *);
128 void virtio_pci_legacy_remove(struct virtio_pci_device *);
129 #else
virtio_pci_legacy_probe(struct virtio_pci_device * vp_dev)130 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
131 {
132 return -ENODEV;
133 }
virtio_pci_legacy_remove(struct virtio_pci_device * vp_dev)134 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
135 {
136 }
137 #endif
138 int virtio_pci_modern_probe(struct virtio_pci_device *);
139 void virtio_pci_modern_remove(struct virtio_pci_device *);
140
141 #endif
142