xref: /haiku/src/add-ons/kernel/busses/virtio/virtio_pci/virtio_pci.h (revision 6d42b430d1738da04cca73e234995ea11556eaaa)
1 /*-
2  * Copyright IBM Corp. 2007
3  *
4  * Authors:
5  *  Anthony Liguori  <aliguori@us.ibm.com>
6  *
7  * This header is BSD licensed so anyone can use the definitions to implement
8  * compatible drivers/servers.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of IBM nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD$
34  */
35 
36 #ifndef _VIRTIO_PCI_H
37 #define _VIRTIO_PCI_H
38 
39 /* VirtIO PCI vendor/device ID. */
40 #define VIRTIO_PCI_VENDORID	0x1AF4
41 #define VIRTIO_PCI_DEVICEID_MIN	0x1000
42 #define VIRTIO_PCI_DEVICEID_LEGACY_MAX	0x103F
43 #define VIRTIO_PCI_DEVICEID_MODERN_MIN	0x1040
44 #define VIRTIO_PCI_DEVICEID_MODERN_MAX	0x107F
45 
46 /*
47  * VirtIO Header, located in BAR 0.
48  */
49 #define VIRTIO_PCI_HOST_FEATURES  0  /* host's supported features (32bit, RO)*/
50 #define VIRTIO_PCI_GUEST_FEATURES 4  /* guest's supported features (32, RW) */
51 #define VIRTIO_PCI_QUEUE_PFN      8  /* physical address of VQ (32, RW) */
52 #define VIRTIO_PCI_QUEUE_NUM      12 /* number of ring entries (16, RO) */
53 #define VIRTIO_PCI_QUEUE_SEL      14 /* current VQ selection (16, RW) */
54 #define VIRTIO_PCI_QUEUE_NOTIFY	  16 /* notify host regarding VQ (16, RW) */
55 #define VIRTIO_PCI_STATUS         18 /* device status register (8, RW) */
56 #define VIRTIO_PCI_ISR            19 /* interrupt status register, reading
57 				      * also clears the register (8, RO) */
58 /* Only if MSIX is enabled: */
59 #define VIRTIO_MSI_CONFIG_VECTOR  20 /* configuration change vector (16, RW) */
60 #define VIRTIO_MSI_QUEUE_VECTOR   22 /* vector for selected VQ notifications
61 					(16, RW) */
62 
63 /* The bit of the ISR which indicates a device has an interrupt. */
64 #define VIRTIO_PCI_ISR_INTR	0x1
65 /* The bit of the ISR which indicates a device configuration change. */
66 #define VIRTIO_PCI_ISR_CONFIG	0x2
67 /* Vector value used to disable MSI for queue. */
68 #define VIRTIO_MSI_NO_VECTOR	0xFFFF
69 
70 /*
71  * The remaining space is defined by each driver as the per-driver
72  * configuration space.
73  */
74 #define VIRTIO_PCI_CONFIG(bus) \
75     ((bus->irq_type != VIRTIO_IRQ_LEGACY) ? 24 : 20)
76 
77 /*
78  * How many bits to shift physical queue address written to QUEUE_PFN.
79  * 12 is historical, and due to x86 page size.
80  */
81 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT	12
82 
83 /* The alignment to use between consumer and producer parts of vring. */
84 #define VIRTIO_PCI_VRING_ALIGN	4096
85 
86 
87 /*
88  * Virtio 1.0 specific
89  */
90 
91 struct virtio_pci_cap {
92 	uint8_t cap_vndr;	/* Generic PCI field: PCI_CAP_ID_VNDR */
93 	uint8_t cap_next;	/* Generic PCI field: next ptr. */
94 	uint8_t cap_len;	/* Generic PCI field: capability length */
95 	uint8_t cfg_type;	/* Identifies the structure. */
96 	uint8_t bar;		/* Where to find it. */
97 	uint8_t padding[3];	/* Pad to full dword. */
98 	uint32_t offset;	/* Offset within bar. */
99 	uint32_t length;	/* Length of the structure, in bytes. */
100 } _PACKED;
101 
102 /* Common configuration */
103 #define VIRTIO_PCI_CAP_COMMON_CFG	1
104 /* Notifications */
105 #define VIRTIO_PCI_CAP_NOTIFY_CFG	2
106 /* ISR Status */
107 #define VIRTIO_PCI_CAP_ISR_CFG		3
108 /* Device specific configuration */
109 #define VIRTIO_PCI_CAP_DEVICE_CFG	4
110 /* PCI configuration access */
111 #define VIRTIO_PCI_CAP_PCI_CFG		5
112 
113 struct virtio_pci_notify_cap {
114 	struct virtio_pci_cap cap;
115 	uint32_t notify_off_multiplier;	/* Multiplier for queue_notify_off. */
116 } _PACKED;
117 
118 struct virtio_pci_cfg_cap {
119 	struct virtio_pci_cap cap;
120 	uint8_t pci_cfg_data[4];	/* Data for BAR access. */
121 } _PACKED;
122 
123 struct virtio_pci_common_cfg {
124 	/* About the whole device. */
125 	uint32_t device_feature_select;	/* read-write */
126 	uint32_t device_feature;	/* read-only for driver */
127 	uint32_t driver_feature_select;	/* read-write */
128 	uint32_t driver_feature;	/* read-write */
129 	uint16_t config_msix_vector;	/* read-write */
130 	uint16_t num_queues;		/* read-only for driver */
131 	uint8_t device_status;		/* read-write */
132 	uint8_t config_generation;	/* read-only for driver */
133 
134 	/* About a specific virtqueue. */
135 	uint16_t queue_select;		/* read-write */
136 	uint16_t queue_size;		/* read-write, power of 2, or 0. */
137 	uint16_t queue_msix_vector;	/* read-write */
138 	uint16_t queue_enable;		/* read-write */
139 	uint16_t queue_notify_off;	/* read-only for driver */
140 	uint64_t queue_desc;		/* read-write */
141 	uint64_t queue_avail;		/* read-write */
142 	uint64_t queue_used;		/* read-write */
143 } _PACKED;
144 
145 #endif /* _VIRTIO_PCI_H */
146