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 */
vp_legacy_probe(struct virtio_pci_legacy_device * ldev)16 int 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(&pci_dev->dev, DMA_BIT_MASK(64));
29 if (rc) {
30 rc = dma_set_mask_and_coherent(&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(&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(pci_dev, 0, 0);
48 if (!ldev->ioaddr)
49 goto err_iomap;
50
51 ldev->isr = ldev->ioaddr + VIRTIO_PCI_ISR;
52
53 ldev->id.vendor = pci_dev->subsystem_vendor;
54 ldev->id.device = pci_dev->subsystem_device;
55
56 return 0;
57 err_iomap:
58 pci_release_region(pci_dev, 0);
59 return rc;
60 }
61 EXPORT_SYMBOL_GPL(vp_legacy_probe);
62
63 /*
64 * vp_legacy_probe: remove and cleanup the legacy virtio pci device
65 * @ldev: the legacy virtio-pci device
66 */
vp_legacy_remove(struct virtio_pci_legacy_device * ldev)67 void vp_legacy_remove(struct virtio_pci_legacy_device *ldev)
68 {
69 struct pci_dev *pci_dev = ldev->pci_dev;
70
71 pci_iounmap(pci_dev, ldev->ioaddr);
72 pci_release_region(pci_dev, 0);
73 }
74 EXPORT_SYMBOL_GPL(vp_legacy_remove);
75
76 /*
77 * vp_legacy_get_features - get features from device
78 * @ldev: the legacy virtio-pci device
79 *
80 * Returns the features read from the device
81 */
vp_legacy_get_features(struct virtio_pci_legacy_device * ldev)82 u64 vp_legacy_get_features(struct virtio_pci_legacy_device *ldev)
83 {
84
85 return ioread32(ldev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
86 }
87 EXPORT_SYMBOL_GPL(vp_legacy_get_features);
88
89 /*
90 * vp_legacy_get_driver_features - get driver features from device
91 * @ldev: the legacy virtio-pci device
92 *
93 * Returns the driver features read from the device
94 */
vp_legacy_get_driver_features(struct virtio_pci_legacy_device * ldev)95 u64 vp_legacy_get_driver_features(struct virtio_pci_legacy_device *ldev)
96 {
97 return ioread32(ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
98 }
99 EXPORT_SYMBOL_GPL(vp_legacy_get_driver_features);
100
101 /*
102 * vp_legacy_set_features - set features to device
103 * @ldev: the legacy virtio-pci device
104 * @features: the features set to device
105 */
vp_legacy_set_features(struct virtio_pci_legacy_device * ldev,u32 features)106 void vp_legacy_set_features(struct virtio_pci_legacy_device *ldev,
107 u32 features)
108 {
109 iowrite32(features, ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
110 }
111 EXPORT_SYMBOL_GPL(vp_legacy_set_features);
112
113 /*
114 * vp_legacy_get_status - get the device status
115 * @ldev: the legacy virtio-pci device
116 *
117 * Returns the status read from device
118 */
vp_legacy_get_status(struct virtio_pci_legacy_device * ldev)119 u8 vp_legacy_get_status(struct virtio_pci_legacy_device *ldev)
120 {
121 return ioread8(ldev->ioaddr + VIRTIO_PCI_STATUS);
122 }
123 EXPORT_SYMBOL_GPL(vp_legacy_get_status);
124
125 /*
126 * vp_legacy_set_status - set status to device
127 * @ldev: the legacy virtio-pci device
128 * @status: the status set to device
129 */
vp_legacy_set_status(struct virtio_pci_legacy_device * ldev,u8 status)130 void vp_legacy_set_status(struct virtio_pci_legacy_device *ldev,
131 u8 status)
132 {
133 iowrite8(status, ldev->ioaddr + VIRTIO_PCI_STATUS);
134 }
135 EXPORT_SYMBOL_GPL(vp_legacy_set_status);
136
137 /*
138 * vp_legacy_queue_vector - set the MSIX vector for a specific virtqueue
139 * @ldev: the legacy virtio-pci device
140 * @index: queue index
141 * @vector: the config vector
142 *
143 * Returns the config vector read from the device
144 */
vp_legacy_queue_vector(struct virtio_pci_legacy_device * ldev,u16 index,u16 vector)145 u16 vp_legacy_queue_vector(struct virtio_pci_legacy_device *ldev,
146 u16 index, u16 vector)
147 {
148 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
149 iowrite16(vector, ldev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
150 /* Flush the write out to device */
151 return ioread16(ldev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
152 }
153 EXPORT_SYMBOL_GPL(vp_legacy_queue_vector);
154
155 /*
156 * vp_legacy_config_vector - set the vector for config interrupt
157 * @ldev: the legacy virtio-pci device
158 * @vector: the config vector
159 *
160 * Returns the config vector read from the device
161 */
vp_legacy_config_vector(struct virtio_pci_legacy_device * ldev,u16 vector)162 u16 vp_legacy_config_vector(struct virtio_pci_legacy_device *ldev,
163 u16 vector)
164 {
165 /* Setup the vector used for configuration events */
166 iowrite16(vector, ldev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
167 /* Verify we had enough resources to assign the vector */
168 /* Will also flush the write out to device */
169 return ioread16(ldev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
170 }
171 EXPORT_SYMBOL_GPL(vp_legacy_config_vector);
172
173 /*
174 * vp_legacy_set_queue_address - set the virtqueue address
175 * @ldev: the legacy virtio-pci device
176 * @index: the queue index
177 * @queue_pfn: pfn of the virtqueue
178 */
vp_legacy_set_queue_address(struct virtio_pci_legacy_device * ldev,u16 index,u32 queue_pfn)179 void vp_legacy_set_queue_address(struct virtio_pci_legacy_device *ldev,
180 u16 index, u32 queue_pfn)
181 {
182 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
183 iowrite32(queue_pfn, ldev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
184 }
185 EXPORT_SYMBOL_GPL(vp_legacy_set_queue_address);
186
187 /*
188 * vp_legacy_get_queue_enable - enable a virtqueue
189 * @ldev: the legacy virtio-pci device
190 * @index: the queue index
191 *
192 * Returns whether a virtqueue is enabled or not
193 */
vp_legacy_get_queue_enable(struct virtio_pci_legacy_device * ldev,u16 index)194 bool vp_legacy_get_queue_enable(struct virtio_pci_legacy_device *ldev,
195 u16 index)
196 {
197 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
198 return ioread32(ldev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
199 }
200 EXPORT_SYMBOL_GPL(vp_legacy_get_queue_enable);
201
202 /*
203 * vp_legacy_get_queue_size - get size for a virtqueue
204 * @ldev: the legacy virtio-pci device
205 * @index: the queue index
206 *
207 * Returns the size of the virtqueue
208 */
vp_legacy_get_queue_size(struct virtio_pci_legacy_device * ldev,u16 index)209 u16 vp_legacy_get_queue_size(struct virtio_pci_legacy_device *ldev,
210 u16 index)
211 {
212 iowrite16(index, ldev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
213 return ioread16(ldev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
214 }
215 EXPORT_SYMBOL_GPL(vp_legacy_get_queue_size);
216
217 MODULE_VERSION("0.1");
218 MODULE_DESCRIPTION("Legacy Virtio PCI Device");
219 MODULE_AUTHOR("Wu Zongyong <wuzongyong@linux.alibaba.com>");
220 MODULE_LICENSE("GPL");
221