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 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. */
94 enum {
95 VP_MSIX_CONFIG_VECTOR = 0,
96 VP_MSIX_VQ_VECTOR = 1,
97 };
98
99 /* Convert a generic virtio device to our structure */
to_vp_device(struct virtio_device * vdev)100 static 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 */
106 void vp_synchronize_vectors(struct virtio_device *vdev);
107 /* the notify function used when creating a virt queue */
108 bool vp_notify(struct virtqueue *vq);
109 /* the config->del_vqs() implementation */
110 void vp_del_vqs(struct virtio_device *vdev);
111 /* the config->find_vqs() implementation */
112 int 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);
116 const 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 */
123 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
124
125 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
126
127 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
128 int virtio_pci_legacy_probe(struct virtio_pci_device *);
129 void virtio_pci_legacy_remove(struct virtio_pci_device *);
130 #else
virtio_pci_legacy_probe(struct virtio_pci_device * vp_dev)131 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
132 {
133 return -ENODEV;
134 }
virtio_pci_legacy_remove(struct virtio_pci_device * vp_dev)135 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
136 {
137 }
138 #endif
139 int virtio_pci_modern_probe(struct virtio_pci_device *);
140 void virtio_pci_modern_remove(struct virtio_pci_device *);
141
142 #endif
143