xref: /openbmc/u-boot/drivers/virtio/virtio_pci.h (revision 60853a9b)
1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /*
3  * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
4  *
5  * From Linux kernel include/uapi/linux/virtio_pci.h
6  */
7 
8 #ifndef _LINUX_VIRTIO_PCI_H
9 #define _LINUX_VIRTIO_PCI_H
10 
11 #ifndef VIRTIO_PCI_NO_LEGACY
12 
13 /* A 32-bit r/o bitmask of the features supported by the host */
14 #define VIRTIO_PCI_HOST_FEATURES	0
15 
16 /* A 32-bit r/w bitmask of features activated by the guest */
17 #define VIRTIO_PCI_GUEST_FEATURES	4
18 
19 /* A 32-bit r/w PFN for the currently selected queue */
20 #define VIRTIO_PCI_QUEUE_PFN		8
21 
22 /* A 16-bit r/o queue size for the currently selected queue */
23 #define VIRTIO_PCI_QUEUE_NUM		12
24 
25 /* A 16-bit r/w queue selector */
26 #define VIRTIO_PCI_QUEUE_SEL		14
27 
28 /* A 16-bit r/w queue notifier */
29 #define VIRTIO_PCI_QUEUE_NOTIFY		16
30 
31 /* An 8-bit device status register */
32 #define VIRTIO_PCI_STATUS		18
33 
34 /*
35  * An 8-bit r/o interrupt status register. Reading the value will return the
36  * current contents of the ISR and will also clear it. This is effectively
37  * a read-and-acknowledge.
38  */
39 #define VIRTIO_PCI_ISR			19
40 
41 /* MSI-X registers: only enabled if MSI-X is enabled */
42 
43 /* A 16-bit vector for configuration changes */
44 #define VIRTIO_MSI_CONFIG_VECTOR	20
45 /* A 16-bit vector for selected queue notifications */
46 #define VIRTIO_MSI_QUEUE_VECTOR		22
47 
48 /*
49  * The remaining space is defined by each driver as the per-driver
50  * configuration space
51  */
52 #define VIRTIO_PCI_CONFIG_OFF(msix)	((msix) ? 24 : 20)
53 
54 /* Virtio ABI version, this must match exactly */
55 #define VIRTIO_PCI_ABI_VERSION		0
56 
57 /*
58  * How many bits to shift physical queue address written to QUEUE_PFN.
59  * 12 is historical, and due to x86 page size.
60  */
61 #define VIRTIO_PCI_QUEUE_ADDR_SHIFT	12
62 
63 /*
64  * The alignment to use between consumer and producer parts of vring.
65  * x86 pagesize again.
66  */
67 #define VIRTIO_PCI_VRING_ALIGN		4096
68 
69 #endif /* VIRTIO_PCI_NO_LEGACY */
70 
71 /* The bit of the ISR which indicates a device configuration change */
72 #define VIRTIO_PCI_ISR_CONFIG		0x2
73 /* Vector value used to disable MSI for queue */
74 #define VIRTIO_MSI_NO_VECTOR		0xffff
75 
76 #ifndef VIRTIO_PCI_NO_MODERN
77 
78 /* IDs for different capabilities.  Must all exist. */
79 
80 /* Common configuration */
81 #define VIRTIO_PCI_CAP_COMMON_CFG	1
82 /* Notifications */
83 #define VIRTIO_PCI_CAP_NOTIFY_CFG	2
84 /* ISR access */
85 #define VIRTIO_PCI_CAP_ISR_CFG		3
86 /* Device specific configuration */
87 #define VIRTIO_PCI_CAP_DEVICE_CFG	4
88 /* PCI configuration access */
89 #define VIRTIO_PCI_CAP_PCI_CFG		5
90 
91 /* This is the PCI capability header: */
92 struct virtio_pci_cap {
93 	__u8 cap_vndr;		/* Generic PCI field: PCI_CAP_ID_VNDR */
94 	__u8 cap_next;		/* Generic PCI field: next ptr */
95 	__u8 cap_len;		/* Generic PCI field: capability length */
96 	__u8 cfg_type;		/* Identifies the structure */
97 	__u8 bar;		/* Where to find it */
98 	__u8 padding[3];	/* Pad to full dword */
99 	__le32 offset;		/* Offset within bar */
100 	__le32 length;		/* Length of the structure, in bytes */
101 };
102 
103 struct virtio_pci_notify_cap {
104 	struct virtio_pci_cap cap;
105 	__le32 notify_off_multiplier;	/* Multiplier for queue_notify_off */
106 };
107 
108 /* Fields in VIRTIO_PCI_CAP_COMMON_CFG: */
109 struct virtio_pci_common_cfg {
110 	/* About the whole device */
111 	__le32 device_feature_select;	/* read-write */
112 	__le32 device_feature;		/* read-only */
113 	__le32 guest_feature_select;	/* read-write */
114 	__le32 guest_feature;		/* read-write */
115 	__le16 msix_config;		/* read-write */
116 	__le16 num_queues;		/* read-only */
117 	__u8 device_status;		/* read-write */
118 	__u8 config_generation;		/* read-only */
119 
120 	/* About a specific virtqueue */
121 	__le16 queue_select;		/* read-write */
122 	__le16 queue_size;		/* read-write, power of 2 */
123 	__le16 queue_msix_vector;	/* read-write */
124 	__le16 queue_enable;		/* read-write */
125 	__le16 queue_notify_off;	/* read-only */
126 	__le32 queue_desc_lo;		/* read-write */
127 	__le32 queue_desc_hi;		/* read-write */
128 	__le32 queue_avail_lo;		/* read-write */
129 	__le32 queue_avail_hi;		/* read-write */
130 	__le32 queue_used_lo;		/* read-write */
131 	__le32 queue_used_hi;		/* read-write */
132 };
133 
134 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
135 struct virtio_pci_cfg_cap {
136 	struct virtio_pci_cap cap;
137 	__u8 pci_cfg_data[4];		/* Data for BAR access */
138 };
139 
140 /* Macro versions of offsets for the Old Timers! */
141 #define VIRTIO_PCI_CAP_VNDR		0
142 #define VIRTIO_PCI_CAP_NEXT		1
143 #define VIRTIO_PCI_CAP_LEN		2
144 #define VIRTIO_PCI_CAP_CFG_TYPE		3
145 #define VIRTIO_PCI_CAP_BAR		4
146 #define VIRTIO_PCI_CAP_OFFSET		8
147 #define VIRTIO_PCI_CAP_LENGTH		12
148 
149 #define VIRTIO_PCI_NOTIFY_CAP_MULT	16
150 
151 #define VIRTIO_PCI_COMMON_DFSELECT	0
152 #define VIRTIO_PCI_COMMON_DF		4
153 #define VIRTIO_PCI_COMMON_GFSELECT	8
154 #define VIRTIO_PCI_COMMON_GF		12
155 #define VIRTIO_PCI_COMMON_MSIX		16
156 #define VIRTIO_PCI_COMMON_NUMQ		18
157 #define VIRTIO_PCI_COMMON_STATUS	20
158 #define VIRTIO_PCI_COMMON_CFGGENERATION	21
159 #define VIRTIO_PCI_COMMON_Q_SELECT	22
160 #define VIRTIO_PCI_COMMON_Q_SIZE	24
161 #define VIRTIO_PCI_COMMON_Q_MSIX	26
162 #define VIRTIO_PCI_COMMON_Q_ENABLE	28
163 #define VIRTIO_PCI_COMMON_Q_NOFF	30
164 #define VIRTIO_PCI_COMMON_Q_DESCLO	32
165 #define VIRTIO_PCI_COMMON_Q_DESCHI	36
166 #define VIRTIO_PCI_COMMON_Q_AVAILLO	40
167 #define VIRTIO_PCI_COMMON_Q_AVAILHI	44
168 #define VIRTIO_PCI_COMMON_Q_USEDLO	48
169 #define VIRTIO_PCI_COMMON_Q_USEDHI	52
170 
171 #endif /* VIRTIO_PCI_NO_MODERN */
172 
173 #endif /* _LINUX_VIRTIO_PCI_H */
174