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 	union {
49 		struct virtio_pci_legacy_device ldev;
50 		struct virtio_pci_modern_device mdev;
51 	};
52 	bool is_legacy;
53 
54 	/* Where to read and clear interrupt */
55 	u8 __iomem *isr;
56 
57 	/* a list of queues so we can dispatch IRQs */
58 	spinlock_t lock;
59 	struct list_head virtqueues;
60 
61 	/* array of all queues for house-keeping */
62 	struct virtio_pci_vq_info **vqs;
63 
64 	/* MSI-X support */
65 	int msix_enabled;
66 	int intx_enabled;
67 	cpumask_var_t *msix_affinity_masks;
68 	/* Name strings for interrupts. This size should be enough,
69 	 * and I'm too lazy to allocate each name separately. */
70 	char (*msix_names)[256];
71 	/* Number of available vectors */
72 	unsigned int msix_vectors;
73 	/* Vectors allocated, excluding per-vq vectors if any */
74 	unsigned int msix_used_vectors;
75 
76 	/* Whether we have vector per vq */
77 	bool per_vq_vectors;
78 
79 	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
80 				      struct virtio_pci_vq_info *info,
81 				      unsigned int idx,
82 				      void (*callback)(struct virtqueue *vq),
83 				      const char *name,
84 				      bool ctx,
85 				      u16 msix_vec);
86 	void (*del_vq)(struct virtio_pci_vq_info *info);
87 
88 	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
89 };
90 
91 /* Constants for MSI-X */
92 /* Use first vector for configuration changes, second and the rest for
93  * virtqueues Thus, we need at least 2 vectors for MSI. */
94 enum {
95 	VP_MSIX_CONFIG_VECTOR = 0,
96 	VP_MSIX_VQ_VECTOR = 1,
97 };
98 
99 /* Convert a generic virtio device to our structure */
100 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
101 {
102 	return container_of(vdev, struct virtio_pci_device, vdev);
103 }
104 
105 /* wait for pending irq handlers */
106 void vp_synchronize_vectors(struct virtio_device *vdev);
107 /* the notify function used when creating a virt queue */
108 bool vp_notify(struct virtqueue *vq);
109 /* the config->del_vqs() implementation */
110 void vp_del_vqs(struct virtio_device *vdev);
111 /* the config->find_vqs() implementation */
112 int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
113 		struct virtqueue *vqs[], vq_callback_t *callbacks[],
114 		const char * const names[], const bool *ctx,
115 		struct irq_affinity *desc);
116 const char *vp_bus_name(struct virtio_device *vdev);
117 
118 /* Setup the affinity for a virtqueue:
119  * - force the affinity for per vq vector
120  * - OR over all affinities for shared MSI
121  * - ignore the affinity request if we're using INTX
122  */
123 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
124 
125 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
126 
127 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
128 int virtio_pci_legacy_probe(struct virtio_pci_device *);
129 void virtio_pci_legacy_remove(struct virtio_pci_device *);
130 #else
131 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
132 {
133 	return -ENODEV;
134 }
135 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
136 {
137 }
138 #endif
139 int virtio_pci_modern_probe(struct virtio_pci_device *);
140 void virtio_pci_modern_remove(struct virtio_pci_device *);
141 
142 #endif
143