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/highmem.h>
29 #include <linux/spinlock.h>
30
31 struct virtio_pci_vq_info {
32 /* the actual virtqueue */
33 struct virtqueue *vq;
34
35 /* the list node for the virtqueues list */
36 struct list_head node;
37
38 /* MSI-X vector (or none) */
39 unsigned msix_vector;
40 };
41
42 /* Our device structure */
43 struct virtio_pci_device {
44 struct virtio_device vdev;
45 struct pci_dev *pci_dev;
46
47 /* In legacy mode, these two point to within ->legacy. */
48 /* Where to read and clear interrupt */
49 u8 __iomem *isr;
50
51 /* Modern only fields */
52 /* The IO mapping for the PCI config space (non-legacy mode) */
53 struct virtio_pci_common_cfg __iomem *common;
54 /* Device-specific data (non-legacy mode) */
55 void __iomem *device;
56 /* Base of vq notifications (non-legacy mode). */
57 void __iomem *notify_base;
58
59 /* So we can sanity-check accesses. */
60 size_t notify_len;
61 size_t device_len;
62
63 /* Capability for when we need to map notifications per-vq. */
64 int notify_map_cap;
65
66 /* Multiply queue_notify_off by this value. (non-legacy mode). */
67 u32 notify_offset_multiplier;
68
69 int modern_bars;
70
71 /* Legacy only field */
72 /* the IO mapping for the PCI config space */
73 void __iomem *ioaddr;
74
75 /* a list of queues so we can dispatch IRQs */
76 spinlock_t lock;
77 struct list_head virtqueues;
78
79 /* array of all queues for house-keeping */
80 struct virtio_pci_vq_info **vqs;
81
82 /* MSI-X support */
83 int msix_enabled;
84 int intx_enabled;
85 cpumask_var_t *msix_affinity_masks;
86 /* Name strings for interrupts. This size should be enough,
87 * and I'm too lazy to allocate each name separately. */
88 char (*msix_names)[256];
89 /* Number of available vectors */
90 unsigned msix_vectors;
91 /* Vectors allocated, excluding per-vq vectors if any */
92 unsigned msix_used_vectors;
93
94 /* Whether we have vector per vq */
95 bool per_vq_vectors;
96
97 struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
98 struct virtio_pci_vq_info *info,
99 unsigned idx,
100 void (*callback)(struct virtqueue *vq),
101 const char *name,
102 bool ctx,
103 u16 msix_vec);
104 void (*del_vq)(struct virtio_pci_vq_info *info);
105
106 u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
107 };
108
109 /* Constants for MSI-X */
110 /* Use first vector for configuration changes, second and the rest for
111 * virtqueues Thus, we need at least 2 vectors for MSI. */
112 enum {
113 VP_MSIX_CONFIG_VECTOR = 0,
114 VP_MSIX_VQ_VECTOR = 1,
115 };
116
117 /* Convert a generic virtio device to our structure */
to_vp_device(struct virtio_device * vdev)118 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
119 {
120 return container_of(vdev, struct virtio_pci_device, vdev);
121 }
122
123 /* wait for pending irq handlers */
124 void vp_synchronize_vectors(struct virtio_device *vdev);
125 /* the notify function used when creating a virt queue */
126 bool vp_notify(struct virtqueue *vq);
127 /* the config->del_vqs() implementation */
128 void vp_del_vqs(struct virtio_device *vdev);
129 /* the config->find_vqs() implementation */
130 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
131 struct virtqueue *vqs[], vq_callback_t *callbacks[],
132 const char * const names[], const bool *ctx,
133 struct irq_affinity *desc);
134 const char *vp_bus_name(struct virtio_device *vdev);
135
136 /* Setup the affinity for a virtqueue:
137 * - force the affinity for per vq vector
138 * - OR over all affinities for shared MSI
139 * - ignore the affinity request if we're using INTX
140 */
141 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
142
143 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
144
145 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
146 int virtio_pci_legacy_probe(struct virtio_pci_device *);
147 void virtio_pci_legacy_remove(struct virtio_pci_device *);
148 #else
virtio_pci_legacy_probe(struct virtio_pci_device * vp_dev)149 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
150 {
151 return -ENODEV;
152 }
virtio_pci_legacy_remove(struct virtio_pci_device * vp_dev)153 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
154 {
155 }
156 #endif
157 int virtio_pci_modern_probe(struct virtio_pci_device *);
158 void virtio_pci_modern_remove(struct virtio_pci_device *);
159
160 #endif
161