1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2021 Microsoft
4 */
5
6 #include <linux/efi.h>
7 #include <linux/hyperv.h>
8 #include <linux/module.h>
9 #include <linux/pci.h>
10
11 #include <drm/drm_aperture.h>
12 #include <drm/drm_atomic_helper.h>
13 #include <drm/drm_drv.h>
14 #include <drm/drm_fb_helper.h>
15 #include <drm/drm_gem_shmem_helper.h>
16 #include <drm/drm_simple_kms_helper.h>
17
18 #include "hyperv_drm.h"
19
20 #define DRIVER_NAME "hyperv_drm"
21 #define DRIVER_DESC "DRM driver for Hyper-V synthetic video device"
22 #define DRIVER_DATE "2020"
23 #define DRIVER_MAJOR 1
24 #define DRIVER_MINOR 0
25
26 #define PCI_VENDOR_ID_MICROSOFT 0x1414
27 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
28
29 DEFINE_DRM_GEM_FOPS(hv_fops);
30
31 static struct drm_driver hyperv_driver = {
32 .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
33
34 .name = DRIVER_NAME,
35 .desc = DRIVER_DESC,
36 .date = DRIVER_DATE,
37 .major = DRIVER_MAJOR,
38 .minor = DRIVER_MINOR,
39
40 .fops = &hv_fops,
41 DRM_GEM_SHMEM_DRIVER_OPS,
42 };
43
hyperv_pci_probe(struct pci_dev * pdev,const struct pci_device_id * ent)44 static int hyperv_pci_probe(struct pci_dev *pdev,
45 const struct pci_device_id *ent)
46 {
47 return 0;
48 }
49
hyperv_pci_remove(struct pci_dev * pdev)50 static void hyperv_pci_remove(struct pci_dev *pdev)
51 {
52 }
53
54 static const struct pci_device_id hyperv_pci_tbl[] = {
55 {
56 .vendor = PCI_VENDOR_ID_MICROSOFT,
57 .device = PCI_DEVICE_ID_HYPERV_VIDEO,
58 },
59 { /* end of list */ }
60 };
61
62 /*
63 * PCI stub to support gen1 VM.
64 */
65 static struct pci_driver hyperv_pci_driver = {
66 .name = KBUILD_MODNAME,
67 .id_table = hyperv_pci_tbl,
68 .probe = hyperv_pci_probe,
69 .remove = hyperv_pci_remove,
70 };
71
hyperv_setup_gen1(struct hyperv_drm_device * hv)72 static int hyperv_setup_gen1(struct hyperv_drm_device *hv)
73 {
74 struct drm_device *dev = &hv->dev;
75 struct pci_dev *pdev;
76 int ret;
77
78 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
79 PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
80 if (!pdev) {
81 drm_err(dev, "Unable to find PCI Hyper-V video\n");
82 return -ENODEV;
83 }
84
85 ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &hyperv_driver);
86 if (ret) {
87 drm_err(dev, "Not able to remove boot fb\n");
88 return ret;
89 }
90
91 if (pci_request_region(pdev, 0, DRIVER_NAME) != 0)
92 drm_warn(dev, "Cannot request framebuffer, boot fb still active?\n");
93
94 if ((pdev->resource[0].flags & IORESOURCE_MEM) == 0) {
95 drm_err(dev, "Resource at bar 0 is not IORESOURCE_MEM\n");
96 ret = -ENODEV;
97 goto error;
98 }
99
100 hv->fb_base = pci_resource_start(pdev, 0);
101 hv->fb_size = pci_resource_len(pdev, 0);
102 if (!hv->fb_base) {
103 drm_err(dev, "Resource not available\n");
104 ret = -ENODEV;
105 goto error;
106 }
107
108 hv->fb_size = min(hv->fb_size,
109 (unsigned long)(hv->mmio_megabytes * 1024 * 1024));
110 hv->vram = devm_ioremap(&pdev->dev, hv->fb_base, hv->fb_size);
111 if (!hv->vram) {
112 drm_err(dev, "Failed to map vram\n");
113 ret = -ENOMEM;
114 }
115
116 error:
117 pci_dev_put(pdev);
118 return ret;
119 }
120
hyperv_setup_gen2(struct hyperv_drm_device * hv,struct hv_device * hdev)121 static int hyperv_setup_gen2(struct hyperv_drm_device *hv,
122 struct hv_device *hdev)
123 {
124 struct drm_device *dev = &hv->dev;
125 int ret;
126
127 drm_aperture_remove_conflicting_framebuffers(screen_info.lfb_base,
128 screen_info.lfb_size,
129 false,
130 &hyperv_driver);
131
132 hv->fb_size = (unsigned long)hv->mmio_megabytes * 1024 * 1024;
133
134 ret = vmbus_allocate_mmio(&hv->mem, hdev, 0, -1, hv->fb_size, 0x100000,
135 true);
136 if (ret) {
137 drm_err(dev, "Failed to allocate mmio\n");
138 return -ENOMEM;
139 }
140
141 /*
142 * Map the VRAM cacheable for performance. This is also required for VM
143 * connect to display properly for ARM64 Linux VM, as the host also maps
144 * the VRAM cacheable.
145 */
146 hv->vram = ioremap_cache(hv->mem->start, hv->fb_size);
147 if (!hv->vram) {
148 drm_err(dev, "Failed to map vram\n");
149 ret = -ENOMEM;
150 goto error;
151 }
152
153 hv->fb_base = hv->mem->start;
154 return 0;
155
156 error:
157 vmbus_free_mmio(hv->mem->start, hv->fb_size);
158 return ret;
159 }
160
hyperv_vmbus_probe(struct hv_device * hdev,const struct hv_vmbus_device_id * dev_id)161 static int hyperv_vmbus_probe(struct hv_device *hdev,
162 const struct hv_vmbus_device_id *dev_id)
163 {
164 struct hyperv_drm_device *hv;
165 struct drm_device *dev;
166 int ret;
167
168 hv = devm_drm_dev_alloc(&hdev->device, &hyperv_driver,
169 struct hyperv_drm_device, dev);
170 if (IS_ERR(hv))
171 return PTR_ERR(hv);
172
173 dev = &hv->dev;
174 init_completion(&hv->wait);
175 hv_set_drvdata(hdev, hv);
176 hv->hdev = hdev;
177
178 ret = hyperv_connect_vsp(hdev);
179 if (ret) {
180 drm_err(dev, "Failed to connect to vmbus.\n");
181 goto err_hv_set_drv_data;
182 }
183
184 if (efi_enabled(EFI_BOOT))
185 ret = hyperv_setup_gen2(hv, hdev);
186 else
187 ret = hyperv_setup_gen1(hv);
188
189 if (ret)
190 goto err_vmbus_close;
191
192 /*
193 * Should be done only once during init and resume. Failing to update
194 * vram location is not fatal. Device will update dirty area till
195 * preferred resolution only.
196 */
197 ret = hyperv_update_vram_location(hdev, hv->fb_base);
198 if (ret)
199 drm_warn(dev, "Failed to update vram location.\n");
200
201 hv->dirt_needed = true;
202
203 ret = hyperv_mode_config_init(hv);
204 if (ret)
205 goto err_vmbus_close;
206
207 ret = drm_dev_register(dev, 0);
208 if (ret) {
209 drm_err(dev, "Failed to register drm driver.\n");
210 goto err_vmbus_close;
211 }
212
213 drm_fbdev_generic_setup(dev, 0);
214
215 return 0;
216
217 err_vmbus_close:
218 vmbus_close(hdev->channel);
219 err_hv_set_drv_data:
220 hv_set_drvdata(hdev, NULL);
221 return ret;
222 }
223
hyperv_vmbus_remove(struct hv_device * hdev)224 static int hyperv_vmbus_remove(struct hv_device *hdev)
225 {
226 struct drm_device *dev = hv_get_drvdata(hdev);
227 struct hyperv_drm_device *hv = to_hv(dev);
228 struct pci_dev *pdev;
229
230 drm_dev_unplug(dev);
231 drm_atomic_helper_shutdown(dev);
232 vmbus_close(hdev->channel);
233 hv_set_drvdata(hdev, NULL);
234
235 /*
236 * Free allocated MMIO memory only on Gen2 VMs.
237 * On Gen1 VMs, release the PCI device
238 */
239 if (efi_enabled(EFI_BOOT)) {
240 vmbus_free_mmio(hv->mem->start, hv->fb_size);
241 } else {
242 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
243 PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
244 if (!pdev) {
245 drm_err(dev, "Unable to find PCI Hyper-V video\n");
246 return -ENODEV;
247 }
248 pci_release_region(pdev, 0);
249 pci_dev_put(pdev);
250 }
251
252 return 0;
253 }
254
hyperv_vmbus_suspend(struct hv_device * hdev)255 static int hyperv_vmbus_suspend(struct hv_device *hdev)
256 {
257 struct drm_device *dev = hv_get_drvdata(hdev);
258 int ret;
259
260 ret = drm_mode_config_helper_suspend(dev);
261 if (ret)
262 return ret;
263
264 vmbus_close(hdev->channel);
265
266 return 0;
267 }
268
hyperv_vmbus_resume(struct hv_device * hdev)269 static int hyperv_vmbus_resume(struct hv_device *hdev)
270 {
271 struct drm_device *dev = hv_get_drvdata(hdev);
272 struct hyperv_drm_device *hv = to_hv(dev);
273 int ret;
274
275 ret = hyperv_connect_vsp(hdev);
276 if (ret)
277 return ret;
278
279 ret = hyperv_update_vram_location(hdev, hv->fb_base);
280 if (ret)
281 return ret;
282
283 return drm_mode_config_helper_resume(dev);
284 }
285
286 static const struct hv_vmbus_device_id hyperv_vmbus_tbl[] = {
287 /* Synthetic Video Device GUID */
288 {HV_SYNTHVID_GUID},
289 {}
290 };
291
292 static struct hv_driver hyperv_hv_driver = {
293 .name = KBUILD_MODNAME,
294 .id_table = hyperv_vmbus_tbl,
295 .probe = hyperv_vmbus_probe,
296 .remove = hyperv_vmbus_remove,
297 .suspend = hyperv_vmbus_suspend,
298 .resume = hyperv_vmbus_resume,
299 .driver = {
300 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
301 },
302 };
303
hyperv_init(void)304 static int __init hyperv_init(void)
305 {
306 int ret;
307
308 ret = pci_register_driver(&hyperv_pci_driver);
309 if (ret != 0)
310 return ret;
311
312 return vmbus_driver_register(&hyperv_hv_driver);
313 }
314
hyperv_exit(void)315 static void __exit hyperv_exit(void)
316 {
317 vmbus_driver_unregister(&hyperv_hv_driver);
318 pci_unregister_driver(&hyperv_pci_driver);
319 }
320
321 module_init(hyperv_init);
322 module_exit(hyperv_exit);
323
324 MODULE_DEVICE_TABLE(pci, hyperv_pci_tbl);
325 MODULE_DEVICE_TABLE(vmbus, hyperv_vmbus_tbl);
326 MODULE_LICENSE("GPL");
327 MODULE_AUTHOR("Deepak Rawat <drawat.floss@gmail.com>");
328 MODULE_DESCRIPTION("DRM driver for Hyper-V synthetic video device");
329