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 
34 struct 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 */
52 struct 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. */
121 enum {
122 	VP_MSIX_CONFIG_VECTOR = 0,
123 	VP_MSIX_VQ_VECTOR = 1,
124 };
125 
126 /* Convert a generic virtio device to our structure */
127 static 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 */
133 void vp_synchronize_vectors(struct virtio_device *vdev);
134 /* the notify function used when creating a virt queue */
135 bool vp_notify(struct virtqueue *vq);
136 /* the config->del_vqs() implementation */
137 void vp_del_vqs(struct virtio_device *vdev);
138 /* the config->find_vqs() implementation */
139 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
140 		       struct virtqueue *vqs[],
141 		       vq_callback_t *callbacks[],
142 		       const char *names[]);
143 const 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  */
150 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
151 
152 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
153 int virtio_pci_legacy_probe(struct virtio_pci_device *);
154 void virtio_pci_legacy_remove(struct virtio_pci_device *);
155 #else
156 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
157 {
158 	return -ENODEV;
159 }
160 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
161 {
162 }
163 #endif
164 int virtio_pci_modern_probe(struct virtio_pci_device *);
165 void virtio_pci_modern_remove(struct virtio_pci_device *);
166 
167 #endif
168