1#ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
2#define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
3/*
4 * Virtio PCI driver - APIs for common functionality for all device versions
5 *
6 * This module allows virtio devices to be used over a virtual PCI device.
7 * This can be used with QEMU based VMMs like KVM or Xen.
8 *
9 * Copyright IBM Corp. 2007
10 * Copyright Red Hat, Inc. 2014
11 *
12 * Authors:
13 *  Anthony Liguori  <aliguori@us.ibm.com>
14 *  Rusty Russell <rusty@rustcorp.com.au>
15 *  Michael S. Tsirkin <mst@redhat.com>
16 *
17 * This work is licensed under the terms of the GNU GPL, version 2 or later.
18 * See the COPYING file in the top-level directory.
19 *
20 */
21
22#include <linux/module.h>
23#include <linux/list.h>
24#include <linux/pci.h>
25#include <linux/slab.h>
26#include <linux/interrupt.h>
27#include <linux/virtio.h>
28#include <linux/virtio_config.h>
29#include <linux/virtio_ring.h>
30#include <linux/virtio_pci.h>
31#include <linux/highmem.h>
32#include <linux/spinlock.h>
33
34struct virtio_pci_vq_info {
35	/* the actual virtqueue */
36	struct virtqueue *vq;
37
38	/* the number of entries in the queue */
39	int num;
40
41	/* the virtual address of the ring queue */
42	void *queue;
43
44	/* the list node for the virtqueues list */
45	struct list_head node;
46
47	/* MSI-X vector (or none) */
48	unsigned msix_vector;
49};
50
51/* Our device structure */
52struct virtio_pci_device {
53	struct virtio_device vdev;
54	struct pci_dev *pci_dev;
55
56	/* In legacy mode, these two point to within ->legacy. */
57	/* Where to read and clear interrupt */
58	u8 __iomem *isr;
59
60	/* Modern only fields */
61	/* The IO mapping for the PCI config space (non-legacy mode) */
62	struct virtio_pci_common_cfg __iomem *common;
63	/* Device-specific data (non-legacy mode)  */
64	void __iomem *device;
65	/* Base of vq notifications (non-legacy mode). */
66	void __iomem *notify_base;
67
68	/* So we can sanity-check accesses. */
69	size_t notify_len;
70	size_t device_len;
71
72	/* Capability for when we need to map notifications per-vq. */
73	int notify_map_cap;
74
75	/* Multiply queue_notify_off by this value. (non-legacy mode). */
76	u32 notify_offset_multiplier;
77
78	/* Legacy only field */
79	/* the IO mapping for the PCI config space */
80	void __iomem *ioaddr;
81
82	/* a list of queues so we can dispatch IRQs */
83	spinlock_t lock;
84	struct list_head virtqueues;
85
86	/* array of all queues for house-keeping */
87	struct virtio_pci_vq_info **vqs;
88
89	/* MSI-X support */
90	int msix_enabled;
91	int intx_enabled;
92	struct msix_entry *msix_entries;
93	cpumask_var_t *msix_affinity_masks;
94	/* Name strings for interrupts. This size should be enough,
95	 * and I'm too lazy to allocate each name separately. */
96	char (*msix_names)[256];
97	/* Number of available vectors */
98	unsigned msix_vectors;
99	/* Vectors allocated, excluding per-vq vectors if any */
100	unsigned msix_used_vectors;
101
102	/* Whether we have vector per vq */
103	bool per_vq_vectors;
104
105	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
106				      struct virtio_pci_vq_info *info,
107				      unsigned idx,
108				      void (*callback)(struct virtqueue *vq),
109				      const char *name,
110				      u16 msix_vec);
111	void (*del_vq)(struct virtio_pci_vq_info *info);
112
113	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
114};
115
116/* Constants for MSI-X */
117/* Use first vector for configuration changes, second and the rest for
118 * virtqueues Thus, we need at least 2 vectors for MSI. */
119enum {
120	VP_MSIX_CONFIG_VECTOR = 0,
121	VP_MSIX_VQ_VECTOR = 1,
122};
123
124/* Convert a generic virtio device to our structure */
125static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
126{
127	return container_of(vdev, struct virtio_pci_device, vdev);
128}
129
130/* wait for pending irq handlers */
131void vp_synchronize_vectors(struct virtio_device *vdev);
132/* the notify function used when creating a virt queue */
133bool vp_notify(struct virtqueue *vq);
134/* the config->del_vqs() implementation */
135void vp_del_vqs(struct virtio_device *vdev);
136/* the config->find_vqs() implementation */
137int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
138		       struct virtqueue *vqs[],
139		       vq_callback_t *callbacks[],
140		       const char *names[]);
141const char *vp_bus_name(struct virtio_device *vdev);
142
143/* Setup the affinity for a virtqueue:
144 * - force the affinity for per vq vector
145 * - OR over all affinities for shared MSI
146 * - ignore the affinity request if we're using INTX
147 */
148int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
149
150#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
151int virtio_pci_legacy_probe(struct virtio_pci_device *);
152void virtio_pci_legacy_remove(struct virtio_pci_device *);
153#else
154static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
155{
156	return -ENODEV;
157}
158static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
159{
160}
161#endif
162int virtio_pci_modern_probe(struct virtio_pci_device *);
163void virtio_pci_modern_remove(struct virtio_pci_device *);
164
165#endif
166