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 	struct virtio_pci_legacy_device ldev;
49 	struct virtio_pci_modern_device mdev;
50 
51 	bool is_legacy;
52 
53 	/* Where to read and clear interrupt */
54 	u8 __iomem *isr;
55 
56 	/* a list of queues so we can dispatch IRQs */
57 	spinlock_t lock;
58 	struct list_head virtqueues;
59 
60 	/* array of all queues for house-keeping */
61 	struct virtio_pci_vq_info **vqs;
62 
63 	/* MSI-X support */
64 	int msix_enabled;
65 	int intx_enabled;
66 	cpumask_var_t *msix_affinity_masks;
67 	/* Name strings for interrupts. This size should be enough,
68 	 * and I'm too lazy to allocate each name separately. */
69 	char (*msix_names)[256];
70 	/* Number of available vectors */
71 	unsigned int msix_vectors;
72 	/* Vectors allocated, excluding per-vq vectors if any */
73 	unsigned int msix_used_vectors;
74 
75 	/* Whether we have vector per vq */
76 	bool per_vq_vectors;
77 
78 	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
79 				      struct virtio_pci_vq_info *info,
80 				      unsigned int idx,
81 				      void (*callback)(struct virtqueue *vq),
82 				      const char *name,
83 				      bool ctx,
84 				      u16 msix_vec);
85 	void (*del_vq)(struct virtio_pci_vq_info *info);
86 
87 	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
88 };
89 
90 /* Constants for MSI-X */
91 /* Use first vector for configuration changes, second and the rest for
92  * virtqueues Thus, we need at least 2 vectors for MSI. */
93 enum {
94 	VP_MSIX_CONFIG_VECTOR = 0,
95 	VP_MSIX_VQ_VECTOR = 1,
96 };
97 
98 /* Convert a generic virtio device to our structure */
to_vp_device(struct virtio_device * vdev)99 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
100 {
101 	return container_of(vdev, struct virtio_pci_device, vdev);
102 }
103 
104 /* wait for pending irq handlers */
105 void vp_synchronize_vectors(struct virtio_device *vdev);
106 /* the notify function used when creating a virt queue */
107 bool vp_notify(struct virtqueue *vq);
108 /* the config->del_vqs() implementation */
109 void vp_del_vqs(struct virtio_device *vdev);
110 /* the config->find_vqs() implementation */
111 int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
112 		struct virtqueue *vqs[], vq_callback_t *callbacks[],
113 		const char * const names[], const bool *ctx,
114 		struct irq_affinity *desc);
115 const char *vp_bus_name(struct virtio_device *vdev);
116 
117 /* Setup the affinity for a virtqueue:
118  * - force the affinity for per vq vector
119  * - OR over all affinities for shared MSI
120  * - ignore the affinity request if we're using INTX
121  */
122 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
123 
124 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
125 
126 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
127 int virtio_pci_legacy_probe(struct virtio_pci_device *);
128 void virtio_pci_legacy_remove(struct virtio_pci_device *);
129 #else
virtio_pci_legacy_probe(struct virtio_pci_device * vp_dev)130 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
131 {
132 	return -ENODEV;
133 }
virtio_pci_legacy_remove(struct virtio_pci_device * vp_dev)134 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
135 {
136 }
137 #endif
138 int virtio_pci_modern_probe(struct virtio_pci_device *);
139 void virtio_pci_modern_remove(struct virtio_pci_device *);
140 
141 #endif
142