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 		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;
59 err_iomap:
60 	pci_release_region(pci_dev, 0);
61 	return rc;
62 }
63 EXPORT_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  */
vp_legacy_remove(struct virtio_pci_legacy_device * ldev)69 void vp_legacy_remove(struct virtio_pci_legacy_device *ldev)
70 {
71 	struct pci_dev *pci_dev = ldev->pci_dev;
72 
73 	pci_iounmap(pci_dev, ldev->ioaddr);
74 	pci_release_region(pci_dev, 0);
75 }
76 EXPORT_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  */
vp_legacy_get_features(struct virtio_pci_legacy_device * ldev)84 u64 vp_legacy_get_features(struct virtio_pci_legacy_device *ldev)
85 {
86 
87 	return ioread32(ldev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
88 }
89 EXPORT_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  */
vp_legacy_get_driver_features(struct virtio_pci_legacy_device * ldev)97 u64 vp_legacy_get_driver_features(struct virtio_pci_legacy_device *ldev)
98 {
99 	return ioread32(ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
100 }
101 EXPORT_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  */
vp_legacy_set_features(struct virtio_pci_legacy_device * ldev,u32 features)108 void vp_legacy_set_features(struct virtio_pci_legacy_device *ldev,
109 			    u32 features)
110 {
111 	iowrite32(features, ldev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
112 }
113 EXPORT_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  */
vp_legacy_get_status(struct virtio_pci_legacy_device * ldev)121 u8 vp_legacy_get_status(struct virtio_pci_legacy_device *ldev)
122 {
123 	return ioread8(ldev->ioaddr + VIRTIO_PCI_STATUS);
124 }
125 EXPORT_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  */
vp_legacy_set_status(struct virtio_pci_legacy_device * ldev,u8 status)132 void vp_legacy_set_status(struct virtio_pci_legacy_device *ldev,
133 				 u8 status)
134 {
135 	iowrite8(status, ldev->ioaddr + VIRTIO_PCI_STATUS);
136 }
137 EXPORT_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 config vector
144  *
145  * Returns the config vector read from the device
146  */
vp_legacy_queue_vector(struct virtio_pci_legacy_device * ldev,u16 index,u16 vector)147 u16 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 }
155 EXPORT_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  */
vp_legacy_config_vector(struct virtio_pci_legacy_device * ldev,u16 vector)164 u16 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 }
173 EXPORT_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  */
vp_legacy_set_queue_address(struct virtio_pci_legacy_device * ldev,u16 index,u32 queue_pfn)181 void 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 }
187 EXPORT_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  */
vp_legacy_get_queue_enable(struct virtio_pci_legacy_device * ldev,u16 index)196 bool 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 }
202 EXPORT_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  */
vp_legacy_get_queue_size(struct virtio_pci_legacy_device * ldev,u16 index)211 u16 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 }
217 EXPORT_SYMBOL_GPL(vp_legacy_get_queue_size);
218 
219 MODULE_VERSION("0.1");
220 MODULE_DESCRIPTION("Legacy Virtio PCI Device");
221 MODULE_AUTHOR("Wu Zongyong <wuzongyong@linux.alibaba.com>");
222 MODULE_LICENSE("GPL");
223