1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2021 Microsoft
  4 */
  5
  6#include <linux/aperture.h>
  7#include <linux/efi.h>
  8#include <linux/hyperv.h>
  9#include <linux/module.h>
 10#include <linux/pci.h>
 11
 12#include <drm/drm_atomic_helper.h>
 13#include <drm/drm_client_setup.h>
 14#include <drm/drm_drv.h>
 15#include <drm/drm_fbdev_shmem.h>
 16#include <drm/drm_gem_shmem_helper.h>
 17#include <drm/drm_simple_kms_helper.h>
 18
 19#include "hyperv_drm.h"
 20
 21#define DRIVER_NAME "hyperv_drm"
 22#define DRIVER_DESC "DRM driver for Hyper-V synthetic video device"
 23#define DRIVER_DATE "2020"
 24#define DRIVER_MAJOR 1
 25#define DRIVER_MINOR 0
 26
 27DEFINE_DRM_GEM_FOPS(hv_fops);
 28
 29static struct drm_driver hyperv_driver = {
 30	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
 31
 32	.name		 = DRIVER_NAME,
 33	.desc		 = DRIVER_DESC,
 34	.date		 = DRIVER_DATE,
 35	.major		 = DRIVER_MAJOR,
 36	.minor		 = DRIVER_MINOR,
 37
 38	.fops		 = &hv_fops,
 39	DRM_GEM_SHMEM_DRIVER_OPS,
 40	DRM_FBDEV_SHMEM_DRIVER_OPS,
 41};
 42
 43static int hyperv_pci_probe(struct pci_dev *pdev,
 44			    const struct pci_device_id *ent)
 45{
 46	return 0;
 47}
 48
 49static void hyperv_pci_remove(struct pci_dev *pdev)
 50{
 51}
 52
 53static const struct pci_device_id hyperv_pci_tbl[] = {
 54	{
 55		.vendor = PCI_VENDOR_ID_MICROSOFT,
 56		.device = PCI_DEVICE_ID_HYPERV_VIDEO,
 57	},
 58	{ /* end of list */ }
 59};
 60
 61/*
 62 * PCI stub to support gen1 VM.
 63 */
 64static struct pci_driver hyperv_pci_driver = {
 65	.name =		KBUILD_MODNAME,
 66	.id_table =	hyperv_pci_tbl,
 67	.probe =	hyperv_pci_probe,
 68	.remove =	hyperv_pci_remove,
 69};
 70
 71static int hyperv_setup_vram(struct hyperv_drm_device *hv,
 72			     struct hv_device *hdev)
 73{
 74	struct drm_device *dev = &hv->dev;
 75	int ret;
 76
 77	hv->fb_size = (unsigned long)hv->mmio_megabytes * 1024 * 1024;
 78
 79	ret = vmbus_allocate_mmio(&hv->mem, hdev, 0, -1, hv->fb_size, 0x100000,
 80				  true);
 81	if (ret) {
 82		drm_err(dev, "Failed to allocate mmio\n");
 83		return -ENOMEM;
 84	}
 85
 86	/*
 87	 * Map the VRAM cacheable for performance. This is also required for VM
 88	 * connect to display properly for ARM64 Linux VM, as the host also maps
 89	 * the VRAM cacheable.
 90	 */
 91	hv->vram = ioremap_cache(hv->mem->start, hv->fb_size);
 92	if (!hv->vram) {
 93		drm_err(dev, "Failed to map vram\n");
 94		ret = -ENOMEM;
 95		goto error;
 96	}
 97
 98	hv->fb_base = hv->mem->start;
 99	return 0;
100
101error:
102	vmbus_free_mmio(hv->mem->start, hv->fb_size);
103	return ret;
104}
105
106static int hyperv_vmbus_probe(struct hv_device *hdev,
107			      const struct hv_vmbus_device_id *dev_id)
108{
109	struct hyperv_drm_device *hv;
110	struct drm_device *dev;
111	int ret;
112
113	hv = devm_drm_dev_alloc(&hdev->device, &hyperv_driver,
114				struct hyperv_drm_device, dev);
115	if (IS_ERR(hv))
116		return PTR_ERR(hv);
117
118	dev = &hv->dev;
119	init_completion(&hv->wait);
120	hv_set_drvdata(hdev, hv);
121	hv->hdev = hdev;
122
123	ret = hyperv_connect_vsp(hdev);
124	if (ret) {
125		drm_err(dev, "Failed to connect to vmbus.\n");
126		goto err_hv_set_drv_data;
127	}
128
129	aperture_remove_all_conflicting_devices(hyperv_driver.name);
130
131	ret = hyperv_setup_vram(hv, hdev);
132	if (ret)
133		goto err_vmbus_close;
134
135	/*
136	 * Should be done only once during init and resume. Failing to update
137	 * vram location is not fatal. Device will update dirty area till
138	 * preferred resolution only.
139	 */
140	ret = hyperv_update_vram_location(hdev, hv->fb_base);
141	if (ret)
142		drm_warn(dev, "Failed to update vram location.\n");
143
144	ret = hyperv_mode_config_init(hv);
145	if (ret)
146		goto err_free_mmio;
147
148	ret = drm_dev_register(dev, 0);
149	if (ret) {
150		drm_err(dev, "Failed to register drm driver.\n");
151		goto err_free_mmio;
152	}
153
154	drm_client_setup(dev, NULL);
155
156	return 0;
157
158err_free_mmio:
159	vmbus_free_mmio(hv->mem->start, hv->fb_size);
160err_vmbus_close:
161	vmbus_close(hdev->channel);
162err_hv_set_drv_data:
163	hv_set_drvdata(hdev, NULL);
164	return ret;
165}
166
167static void hyperv_vmbus_remove(struct hv_device *hdev)
168{
169	struct drm_device *dev = hv_get_drvdata(hdev);
170	struct hyperv_drm_device *hv = to_hv(dev);
171
172	drm_dev_unplug(dev);
173	drm_atomic_helper_shutdown(dev);
174	vmbus_close(hdev->channel);
175	hv_set_drvdata(hdev, NULL);
176
177	vmbus_free_mmio(hv->mem->start, hv->fb_size);
178}
179
180static void hyperv_vmbus_shutdown(struct hv_device *hdev)
181{
182	drm_atomic_helper_shutdown(hv_get_drvdata(hdev));
183}
184
185static int hyperv_vmbus_suspend(struct hv_device *hdev)
186{
187	struct drm_device *dev = hv_get_drvdata(hdev);
188	int ret;
189
190	ret = drm_mode_config_helper_suspend(dev);
191	if (ret)
192		return ret;
193
194	vmbus_close(hdev->channel);
195
196	return 0;
197}
198
199static int hyperv_vmbus_resume(struct hv_device *hdev)
200{
201	struct drm_device *dev = hv_get_drvdata(hdev);
202	struct hyperv_drm_device *hv = to_hv(dev);
203	int ret;
204
205	ret = hyperv_connect_vsp(hdev);
206	if (ret)
207		return ret;
208
209	ret = hyperv_update_vram_location(hdev, hv->fb_base);
210	if (ret)
211		return ret;
212
213	return drm_mode_config_helper_resume(dev);
214}
215
216static const struct hv_vmbus_device_id hyperv_vmbus_tbl[] = {
217	/* Synthetic Video Device GUID */
218	{HV_SYNTHVID_GUID},
219	{}
220};
221
222static struct hv_driver hyperv_hv_driver = {
223	.name = KBUILD_MODNAME,
224	.id_table = hyperv_vmbus_tbl,
225	.probe = hyperv_vmbus_probe,
226	.remove = hyperv_vmbus_remove,
227	.shutdown = hyperv_vmbus_shutdown,
228	.suspend = hyperv_vmbus_suspend,
229	.resume = hyperv_vmbus_resume,
230	.driver = {
231		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
232	},
233};
234
235static int __init hyperv_init(void)
236{
237	int ret;
238
239	if (drm_firmware_drivers_only())
240		return -ENODEV;
241
242	ret = pci_register_driver(&hyperv_pci_driver);
243	if (ret != 0)
244		return ret;
245
246	return vmbus_driver_register(&hyperv_hv_driver);
247}
248
249static void __exit hyperv_exit(void)
250{
251	vmbus_driver_unregister(&hyperv_hv_driver);
252	pci_unregister_driver(&hyperv_pci_driver);
253}
254
255module_init(hyperv_init);
256module_exit(hyperv_exit);
257
258MODULE_DEVICE_TABLE(pci, hyperv_pci_tbl);
259MODULE_DEVICE_TABLE(vmbus, hyperv_vmbus_tbl);
260MODULE_LICENSE("GPL");
261MODULE_AUTHOR("Deepak Rawat <drawat.floss@gmail.com>");
262MODULE_DESCRIPTION("DRM driver for Hyper-V synthetic video device");