xref: /linux/drivers/virtio/virtio_pci_common.h (revision 957e3facd147510f2cf8780e38606f1d707f0e33)
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 #define VIRTIO_PCI_NO_LEGACY
31 #include <linux/virtio_pci.h>
32 #include <linux/highmem.h>
33 #include <linux/spinlock.h>
34 
35 struct virtio_pci_vq_info {
36 	/* the actual virtqueue */
37 	struct virtqueue *vq;
38 
39 	/* the number of entries in the queue */
40 	int num;
41 
42 	/* the virtual address of the ring queue */
43 	void *queue;
44 
45 	/* the list node for the virtqueues list */
46 	struct list_head node;
47 
48 	/* MSI-X vector (or none) */
49 	unsigned msix_vector;
50 };
51 
52 /* Our device structure */
53 struct virtio_pci_device {
54 	struct virtio_device vdev;
55 	struct pci_dev *pci_dev;
56 
57 	/* the IO mapping for the PCI config space */
58 	void __iomem *ioaddr;
59 
60 	/* the IO mapping for ISR operation */
61 	void __iomem *isr;
62 
63 	/* a list of queues so we can dispatch IRQs */
64 	spinlock_t lock;
65 	struct list_head virtqueues;
66 
67 	/* array of all queues for house-keeping */
68 	struct virtio_pci_vq_info **vqs;
69 
70 	/* MSI-X support */
71 	int msix_enabled;
72 	int intx_enabled;
73 	struct msix_entry *msix_entries;
74 	cpumask_var_t *msix_affinity_masks;
75 	/* Name strings for interrupts. This size should be enough,
76 	 * and I'm too lazy to allocate each name separately. */
77 	char (*msix_names)[256];
78 	/* Number of available vectors */
79 	unsigned msix_vectors;
80 	/* Vectors allocated, excluding per-vq vectors if any */
81 	unsigned msix_used_vectors;
82 
83 	/* Whether we have vector per vq */
84 	bool per_vq_vectors;
85 
86 	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
87 				      struct virtio_pci_vq_info *info,
88 				      unsigned idx,
89 				      void (*callback)(struct virtqueue *vq),
90 				      const char *name,
91 				      u16 msix_vec);
92 	void (*del_vq)(struct virtio_pci_vq_info *info);
93 
94 	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
95 };
96 
97 /* Constants for MSI-X */
98 /* Use first vector for configuration changes, second and the rest for
99  * virtqueues Thus, we need at least 2 vectors for MSI. */
100 enum {
101 	VP_MSIX_CONFIG_VECTOR = 0,
102 	VP_MSIX_VQ_VECTOR = 1,
103 };
104 
105 /* Convert a generic virtio device to our structure */
106 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
107 {
108 	return container_of(vdev, struct virtio_pci_device, vdev);
109 }
110 
111 /* wait for pending irq handlers */
112 void vp_synchronize_vectors(struct virtio_device *vdev);
113 /* the notify function used when creating a virt queue */
114 bool vp_notify(struct virtqueue *vq);
115 /* the config->del_vqs() implementation */
116 void vp_del_vqs(struct virtio_device *vdev);
117 /* the config->find_vqs() implementation */
118 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
119 		       struct virtqueue *vqs[],
120 		       vq_callback_t *callbacks[],
121 		       const char *names[]);
122 const char *vp_bus_name(struct virtio_device *vdev);
123 
124 /* Setup the affinity for a virtqueue:
125  * - force the affinity for per vq vector
126  * - OR over all affinities for shared MSI
127  * - ignore the affinity request if we're using INTX
128  */
129 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
130 void virtio_pci_release_dev(struct device *);
131 
132 #ifdef CONFIG_PM_SLEEP
133 extern const struct dev_pm_ops virtio_pci_pm_ops;
134 #endif
135 
136 #endif
137