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	int modern_bars;
79
80	/* Legacy only field */
81	/* the IO mapping for the PCI config space */
82	void __iomem *ioaddr;
83
84	/* a list of queues so we can dispatch IRQs */
85	spinlock_t lock;
86	struct list_head virtqueues;
87
88	/* array of all queues for house-keeping */
89	struct virtio_pci_vq_info **vqs;
90
91	/* MSI-X support */
92	int msix_enabled;
93	int intx_enabled;
94	struct msix_entry *msix_entries;
95	cpumask_var_t *msix_affinity_masks;
96	/* Name strings for interrupts. This size should be enough,
97	 * and I'm too lazy to allocate each name separately. */
98	char (*msix_names)[256];
99	/* Number of available vectors */
100	unsigned msix_vectors;
101	/* Vectors allocated, excluding per-vq vectors if any */
102	unsigned msix_used_vectors;
103
104	/* Whether we have vector per vq */
105	bool per_vq_vectors;
106
107	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
108				      struct virtio_pci_vq_info *info,
109				      unsigned idx,
110				      void (*callback)(struct virtqueue *vq),
111				      const char *name,
112				      u16 msix_vec);
113	void (*del_vq)(struct virtio_pci_vq_info *info);
114
115	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
116};
117
118/* Constants for MSI-X */
119/* Use first vector for configuration changes, second and the rest for
120 * virtqueues Thus, we need at least 2 vectors for MSI. */
121enum {
122	VP_MSIX_CONFIG_VECTOR = 0,
123	VP_MSIX_VQ_VECTOR = 1,
124};
125
126/* Convert a generic virtio device to our structure */
127static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
128{
129	return container_of(vdev, struct virtio_pci_device, vdev);
130}
131
132/* wait for pending irq handlers */
133void vp_synchronize_vectors(struct virtio_device *vdev);
134/* the notify function used when creating a virt queue */
135bool vp_notify(struct virtqueue *vq);
136/* the config->del_vqs() implementation */
137void vp_del_vqs(struct virtio_device *vdev);
138/* the config->find_vqs() implementation */
139int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
140		       struct virtqueue *vqs[],
141		       vq_callback_t *callbacks[],
142		       const char *names[]);
143const char *vp_bus_name(struct virtio_device *vdev);
144
145/* Setup the affinity for a virtqueue:
146 * - force the affinity for per vq vector
147 * - OR over all affinities for shared MSI
148 * - ignore the affinity request if we're using INTX
149 */
150int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
151
152#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
153int virtio_pci_legacy_probe(struct virtio_pci_device *);
154void virtio_pci_legacy_remove(struct virtio_pci_device *);
155#else
156static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
157{
158	return -ENODEV;
159}
160static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
161{
162}
163#endif
164int virtio_pci_modern_probe(struct virtio_pci_device *);
165void virtio_pci_modern_remove(struct virtio_pci_device *);
166
167#endif
168