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
31struct 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 */
43struct 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. */
112enum {
113	VP_MSIX_CONFIG_VECTOR = 0,
114	VP_MSIX_VQ_VECTOR = 1,
115};
116
117/* Convert a generic virtio device to our structure */
118static 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 */
124void vp_synchronize_vectors(struct virtio_device *vdev);
125/* the notify function used when creating a virt queue */
126bool vp_notify(struct virtqueue *vq);
127/* the config->del_vqs() implementation */
128void vp_del_vqs(struct virtio_device *vdev);
129/* the config->find_vqs() implementation */
130int 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);
134const 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 */
141int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
142
143const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
144
145#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
146int virtio_pci_legacy_probe(struct virtio_pci_device *);
147void virtio_pci_legacy_remove(struct virtio_pci_device *);
148#else
149static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
150{
151	return -ENODEV;
152}
153static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
154{
155}
156#endif
157int virtio_pci_modern_probe(struct virtio_pci_device *);
158void virtio_pci_modern_remove(struct virtio_pci_device *);
159
160#endif
161