xref: /dpdk/drivers/net/virtio/virtio_pci.c (revision 92ebda07ee58cf6966305ba03b50b81debfb2d98)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #include <stdint.h>
34 
35 #include "virtio_pci.h"
36 #include "virtio_logs.h"
37 
38 static uint8_t vtpci_get_status(struct virtio_hw *);
39 
40 void
41 vtpci_read_dev_config(struct virtio_hw *hw, uint64_t offset,
42 		void *dst, int length)
43 {
44 	uint64_t off;
45 	uint8_t *d;
46 	int size;
47 
48 	off = VIRTIO_PCI_CONFIG(hw) + offset;
49 	for (d = dst; length > 0; d += size, off += size, length -= size) {
50 		if (length >= 4) {
51 			size = 4;
52 			*(uint32_t *)d = VIRTIO_READ_REG_4(hw, off);
53 		} else if (length >= 2) {
54 			size = 2;
55 			*(uint16_t *)d = VIRTIO_READ_REG_2(hw, off);
56 		} else {
57 			size = 1;
58 			*d = VIRTIO_READ_REG_1(hw, off);
59 		}
60 	}
61 }
62 
63 void
64 vtpci_write_dev_config(struct virtio_hw *hw, uint64_t offset,
65 		void *src, int length)
66 {
67 	uint64_t off;
68 	uint8_t *s;
69 	int size;
70 
71 	off = VIRTIO_PCI_CONFIG(hw) + offset;
72 	for (s = src; length > 0; s += size, off += size, length -= size) {
73 		if (length >= 4) {
74 			size = 4;
75 			VIRTIO_WRITE_REG_4(hw, off, *(uint32_t *)s);
76 		} else if (length >= 2) {
77 			size = 2;
78 			VIRTIO_WRITE_REG_2(hw, off, *(uint16_t *)s);
79 		} else {
80 			size = 1;
81 			VIRTIO_WRITE_REG_1(hw, off, *s);
82 		}
83 	}
84 }
85 
86 uint32_t
87 vtpci_negotiate_features(struct virtio_hw *hw, uint32_t host_features)
88 {
89 	uint32_t features;
90 	/*
91 	 * Limit negotiated features to what the driver, virtqueue, and
92 	 * host all support.
93 	 */
94 	features = host_features & hw->guest_features;
95 
96 	VIRTIO_WRITE_REG_4(hw, VIRTIO_PCI_GUEST_FEATURES, features);
97 	return features;
98 }
99 
100 
101 void
102 vtpci_reset(struct virtio_hw *hw)
103 {
104 	/*
105 	 * Setting the status to RESET sets the host device to
106 	 * the original, uninitialized state.
107 	 */
108 	vtpci_set_status(hw, VIRTIO_CONFIG_STATUS_RESET);
109 	vtpci_get_status(hw);
110 }
111 
112 void
113 vtpci_reinit_complete(struct virtio_hw *hw)
114 {
115 	vtpci_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER_OK);
116 }
117 
118 static uint8_t
119 vtpci_get_status(struct virtio_hw *hw)
120 {
121 	return VIRTIO_READ_REG_1(hw, VIRTIO_PCI_STATUS);
122 }
123 
124 void
125 vtpci_set_status(struct virtio_hw *hw, uint8_t status)
126 {
127 	if (status != VIRTIO_CONFIG_STATUS_RESET)
128 		status = (uint8_t)(status | vtpci_get_status(hw));
129 
130 	VIRTIO_WRITE_REG_1(hw, VIRTIO_PCI_STATUS, status);
131 }
132 
133 uint8_t
134 vtpci_isr(struct virtio_hw *hw)
135 {
136 
137 	return VIRTIO_READ_REG_1(hw, VIRTIO_PCI_ISR);
138 }
139 
140 
141 /* Enable one vector (0) for Link State Intrerrupt */
142 uint16_t
143 vtpci_irq_config(struct virtio_hw *hw, uint16_t vec)
144 {
145 	VIRTIO_WRITE_REG_2(hw, VIRTIO_MSI_CONFIG_VECTOR, vec);
146 	return VIRTIO_READ_REG_2(hw, VIRTIO_MSI_CONFIG_VECTOR);
147 }
148