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 list node for the virtqueues list */
39 	struct list_head node;
40 
41 	/* MSI-X vector (or none) */
42 	unsigned msix_vector;
43 };
44 
45 /* Our device structure */
46 struct virtio_pci_device {
47 	struct virtio_device vdev;
48 	struct pci_dev *pci_dev;
49 
50 	/* In legacy mode, these two point to within ->legacy. */
51 	/* Where to read and clear interrupt */
52 	u8 __iomem *isr;
53 
54 	/* Modern only fields */
55 	/* The IO mapping for the PCI config space (non-legacy mode) */
56 	struct virtio_pci_common_cfg __iomem *common;
57 	/* Device-specific data (non-legacy mode)  */
58 	void __iomem *device;
59 	/* Base of vq notifications (non-legacy mode). */
60 	void __iomem *notify_base;
61 
62 	/* So we can sanity-check accesses. */
63 	size_t notify_len;
64 	size_t device_len;
65 
66 	/* Capability for when we need to map notifications per-vq. */
67 	int notify_map_cap;
68 
69 	/* Multiply queue_notify_off by this value. (non-legacy mode). */
70 	u32 notify_offset_multiplier;
71 
72 	int modern_bars;
73 
74 	/* Legacy only field */
75 	/* the IO mapping for the PCI config space */
76 	void __iomem *ioaddr;
77 
78 	/* a list of queues so we can dispatch IRQs */
79 	spinlock_t lock;
80 	struct list_head virtqueues;
81 
82 	/* array of all queues for house-keeping */
83 	struct virtio_pci_vq_info **vqs;
84 
85 	/* MSI-X support */
86 	int msix_enabled;
87 	int intx_enabled;
88 	cpumask_var_t *msix_affinity_masks;
89 	/* Name strings for interrupts. This size should be enough,
90 	 * and I'm too lazy to allocate each name separately. */
91 	char (*msix_names)[256];
92 	/* Number of available vectors */
93 	unsigned msix_vectors;
94 	/* Vectors allocated, excluding per-vq vectors if any */
95 	unsigned msix_used_vectors;
96 
97 	/* Whether we have vector per vq */
98 	bool per_vq_vectors;
99 
100 	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
101 				      struct virtio_pci_vq_info *info,
102 				      unsigned idx,
103 				      void (*callback)(struct virtqueue *vq),
104 				      const char *name,
105 				      bool ctx,
106 				      u16 msix_vec);
107 	void (*del_vq)(struct virtio_pci_vq_info *info);
108 
109 	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
110 };
111 
112 /* Constants for MSI-X */
113 /* Use first vector for configuration changes, second and the rest for
114  * virtqueues Thus, we need at least 2 vectors for MSI. */
115 enum {
116 	VP_MSIX_CONFIG_VECTOR = 0,
117 	VP_MSIX_VQ_VECTOR = 1,
118 };
119 
120 /* Convert a generic virtio device to our structure */
121 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
122 {
123 	return container_of(vdev, struct virtio_pci_device, vdev);
124 }
125 
126 /* wait for pending irq handlers */
127 void vp_synchronize_vectors(struct virtio_device *vdev);
128 /* the notify function used when creating a virt queue */
129 bool vp_notify(struct virtqueue *vq);
130 /* the config->del_vqs() implementation */
131 void vp_del_vqs(struct virtio_device *vdev);
132 /* the config->find_vqs() implementation */
133 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
134 		struct virtqueue *vqs[], vq_callback_t *callbacks[],
135 		const char * const names[], const bool *ctx,
136 		struct irq_affinity *desc);
137 const char *vp_bus_name(struct virtio_device *vdev);
138 
139 /* Setup the affinity for a virtqueue:
140  * - force the affinity for per vq vector
141  * - OR over all affinities for shared MSI
142  * - ignore the affinity request if we're using INTX
143  */
144 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
145 
146 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
147 
148 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
149 int virtio_pci_legacy_probe(struct virtio_pci_device *);
150 void virtio_pci_legacy_remove(struct virtio_pci_device *);
151 #else
152 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
153 {
154 	return -ENODEV;
155 }
156 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
157 {
158 }
159 #endif
160 int virtio_pci_modern_probe(struct virtio_pci_device *);
161 void virtio_pci_modern_remove(struct virtio_pci_device *);
162 
163 #endif
164