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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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