1// SPDX-License-Identifier: GPL-2.0-or-later
2
3#include "linux/virtio_pci.h"
4#include <linux/virtio_pci_legacy.h>
5#include <linux/module.h>
6#include <linux/pci.h>
7
8
9/*
10 * vp_legacy_probe: probe the legacy virtio pci device, note that the
11 * caller is required to enable PCI device before calling this function.
12 * @ldev: the legacy virtio-pci device
13 *
14 * Return 0 on succeed otherwise fail
15 */
16int vp_legacy_probe(struct virtio_pci_legacy_device *ldev)
17{
18 struct pci_dev *pci_dev = ldev->pci_dev;
19 int rc;
20
21 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
22 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
23 return -ENODEV;
24
25 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION)
26 return -ENODEV;
27
28 rc = dma_set_mask(dev: &pci_dev->dev, DMA_BIT_MASK(64));
29 if (rc) {
30 rc = dma_set_mask_and_coherent(dev: &pci_dev->dev, DMA_BIT_MASK(32));
31 } else {
32 /*
33 * The virtio ring base address is expressed as a 32-bit PFN,
34 * with a page size of 1 << VIRTIO_PCI_QUEUE_ADDR_SHIFT.
35 */
36 dma_set_coherent_mask(dev: &pci_dev->dev,
37 DMA_BIT_MASK(32 + VIRTIO_PCI_QUEUE_ADDR_SHIFT));
38 }
39
40 if (rc)
41 dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n");
42
43 rc = pci_request_region(pci_dev, 0, "virtio-pci-legacy");
44 if (rc)
45 return rc;
46
47 ldev->ioaddr = pci_iomap(dev: pci_dev, bar: 0, max: 0);
48 if (!ldev->ioaddr) {
49 rc = -EIO;
50 goto err_iomap;
51 }
52
53 ldev->isr = ldev->ioaddr + VIRTIO_PCI_ISR;
54
55 ldev->id.vendor = pci_dev->subsystem_vendor;
56 ldev->id.device = pci_dev->subsystem_device;
57
58 return 0;
59err_iomap:
60 pci_release_region(pci_dev, 0);
61 return rc;
62}
63EXPORT_SYMBOL_GPL(vp_legacy_probe);
64
65/*
66 * vp_legacy_probe: remove and cleanup the legacy virtio pci device
67 * @ldev: the legacy virtio-pci device
68 */
69void vp_legacy_remove(struct virtio_pci_legacy_device *ldev)
70{
71 struct pci_dev *pci_dev = ldev->pci_dev;
72
73 pci_iounmap(dev: pci_dev, ldev->ioaddr);
74 pci_release_region(pci_dev, 0);
75}
76EXPORT_SYMBOL_GPL(vp_legacy_remove);
77
78/*
79 * vp_legacy_get_features - get features from device
80 * @ldev: the legacy virtio-pci device
81 *
82 * Returns the features read from the device
83 */
84u64 vp_legacy_get_features(struct virtio_pci_legacy_device *ldev)
85{
86
87 return ioread32(ldev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
88}
89EXPORT_SYMBOL_GPL(vp_legacy_get_features);
90
91/*
92 * vp_legacy_get_driver_features - get driver features from device
93 * @ldev: the legacy virtio-pci device
94 *
95 * Returns the driver features read from the device
96 */
97u64 vp_legacy_get_driver_features(struct virtio_pci_legacy_device *ldev)
98{
99 return ioread32(ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
100}
101EXPORT_SYMBOL_GPL(vp_legacy_get_driver_features);
102
103/*
104 * vp_legacy_set_features - set features to device
105 * @ldev: the legacy virtio-pci device
106 * @features: the features set to device
107 */
108void vp_legacy_set_features(struct virtio_pci_legacy_device *ldev,
109 u32 features)
110{
111 iowrite32(features, ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
112}
113EXPORT_SYMBOL_GPL(vp_legacy_set_features);
114
115/*
116 * vp_legacy_get_status - get the device status
117 * @ldev: the legacy virtio-pci device
118 *
119 * Returns the status read from device
120 */
121u8 vp_legacy_get_status(struct virtio_pci_legacy_device *ldev)
122{
123 return ioread8(ldev->ioaddr + VIRTIO_PCI_STATUS);
124}
125EXPORT_SYMBOL_GPL(vp_legacy_get_status);
126
127/*
128 * vp_legacy_set_status - set status to device
129 * @ldev: the legacy virtio-pci device
130 * @status: the status set to device
131 */
132void vp_legacy_set_status(struct virtio_pci_legacy_device *ldev,
133 u8 status)
134{
135 iowrite8(status, ldev->ioaddr + VIRTIO_PCI_STATUS);
136}
137EXPORT_SYMBOL_GPL(vp_legacy_set_status);
138
139/*
140 * vp_legacy_queue_vector - set the MSIX vector for a specific virtqueue
141 * @ldev: the legacy virtio-pci device
142 * @index: queue index
143 * @vector: the queue vector
144 *
145 * Returns the queue vector read from the device
146 */
147u16 vp_legacy_queue_vector(struct virtio_pci_legacy_device *ldev,
148 u16 index, u16 vector)
149{
150 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
151 iowrite16(vector, ldev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
152 /* Flush the write out to device */
153 return ioread16(ldev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
154}
155EXPORT_SYMBOL_GPL(vp_legacy_queue_vector);
156
157/*
158 * vp_legacy_config_vector - set the vector for config interrupt
159 * @ldev: the legacy virtio-pci device
160 * @vector: the config vector
161 *
162 * Returns the config vector read from the device
163 */
164u16 vp_legacy_config_vector(struct virtio_pci_legacy_device *ldev,
165 u16 vector)
166{
167 /* Setup the vector used for configuration events */
168 iowrite16(vector, ldev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
169 /* Verify we had enough resources to assign the vector */
170 /* Will also flush the write out to device */
171 return ioread16(ldev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
172}
173EXPORT_SYMBOL_GPL(vp_legacy_config_vector);
174
175/*
176 * vp_legacy_set_queue_address - set the virtqueue address
177 * @ldev: the legacy virtio-pci device
178 * @index: the queue index
179 * @queue_pfn: pfn of the virtqueue
180 */
181void vp_legacy_set_queue_address(struct virtio_pci_legacy_device *ldev,
182 u16 index, u32 queue_pfn)
183{
184 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
185 iowrite32(queue_pfn, ldev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
186}
187EXPORT_SYMBOL_GPL(vp_legacy_set_queue_address);
188
189/*
190 * vp_legacy_get_queue_enable - enable a virtqueue
191 * @ldev: the legacy virtio-pci device
192 * @index: the queue index
193 *
194 * Returns whether a virtqueue is enabled or not
195 */
196bool vp_legacy_get_queue_enable(struct virtio_pci_legacy_device *ldev,
197 u16 index)
198{
199 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
200 return ioread32(ldev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
201}
202EXPORT_SYMBOL_GPL(vp_legacy_get_queue_enable);
203
204/*
205 * vp_legacy_get_queue_size - get size for a virtqueue
206 * @ldev: the legacy virtio-pci device
207 * @index: the queue index
208 *
209 * Returns the size of the virtqueue
210 */
211u16 vp_legacy_get_queue_size(struct virtio_pci_legacy_device *ldev,
212 u16 index)
213{
214 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
215 return ioread16(ldev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
216}
217EXPORT_SYMBOL_GPL(vp_legacy_get_queue_size);
218
219MODULE_VERSION("0.1");
220MODULE_DESCRIPTION("Legacy Virtio PCI Device");
221MODULE_AUTHOR("Wu Zongyong <wuzongyong@linux.alibaba.com>");
222MODULE_LICENSE("GPL");
223