1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
new file mode 100644
index 000000000000..eb06c92c4bfd
--- /dev/null
+++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2021 Microsoft
+ */
+
+#include <linux/efi.h>
+#include <linux/hyperv.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <drm/drm_aperture.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_simple_kms_helper.h>
+
+#include "hyperv_drm.h"
+
+#define DRIVER_NAME "hyperv_drm"
+#define DRIVER_DESC "DRM driver for Hyper-V synthetic video device"
+#define DRIVER_DATE "2020"
+#define DRIVER_MAJOR 1
+#define DRIVER_MINOR 0
+
+#define PCI_VENDOR_ID_MICROSOFT 0x1414
+#define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
+
+DEFINE_DRM_GEM_FOPS(hv_fops);
+
+static struct drm_driver hyperv_driver = {
+	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+
+	.name		 = DRIVER_NAME,
+	.desc		 = DRIVER_DESC,
+	.date		 = DRIVER_DATE,
+	.major		 = DRIVER_MAJOR,
+	.minor		 = DRIVER_MINOR,
+
+	.fops		 = &hv_fops,
+	DRM_GEM_SHMEM_DRIVER_OPS,
+};
+
+static int hyperv_pci_probe(struct pci_dev *pdev,
+			    const struct pci_device_id *ent)
+{
+	return 0;
+}
+
+static void hyperv_pci_remove(struct pci_dev *pdev)
+{
+}
+
+static const struct pci_device_id hyperv_pci_tbl[] = {
+	{
+		.vendor = PCI_VENDOR_ID_MICROSOFT,
+		.device = PCI_DEVICE_ID_HYPERV_VIDEO,
+	},
+	{ /* end of list */ }
+};
+
+/*
+ * PCI stub to support gen1 VM.
+ */
+static struct pci_driver hyperv_pci_driver = {
+	.name =		KBUILD_MODNAME,
+	.id_table =	hyperv_pci_tbl,
+	.probe =	hyperv_pci_probe,
+	.remove =	hyperv_pci_remove,
+};
+
+static int hyperv_setup_gen1(struct hyperv_drm_device *hv)
+{
+	struct drm_device *dev = &hv->dev;
+	struct pci_dev *pdev;
+	int ret;
+
+	pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
+			      PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
+	if (!pdev) {
+		drm_err(dev, "Unable to find PCI Hyper-V video\n");
+		return -ENODEV;
+	}
+
+	ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, "hypervdrmfb");
+	if (ret) {
+		drm_err(dev, "Not able to remove boot fb\n");
+		return ret;
+	}
+
+	if (pci_request_region(pdev, 0, DRIVER_NAME) != 0)
+		drm_warn(dev, "Cannot request framebuffer, boot fb still active?\n");
+
+	if ((pdev->resource[0].flags & IORESOURCE_MEM) == 0) {
+		drm_err(dev, "Resource at bar 0 is not IORESOURCE_MEM\n");
+		ret = -ENODEV;
+		goto error;
+	}
+
+	hv->fb_base = pci_resource_start(pdev, 0);
+	hv->fb_size = pci_resource_len(pdev, 0);
+	if (!hv->fb_base) {
+		drm_err(dev, "Resource not available\n");
+		ret = -ENODEV;
+		goto error;
+	}
+
+	hv->fb_size = min(hv->fb_size,
+			  (unsigned long)(hv->mmio_megabytes * 1024 * 1024));
+	hv->vram = devm_ioremap(&pdev->dev, hv->fb_base, hv->fb_size);
+	if (!hv->vram) {
+		drm_err(dev, "Failed to map vram\n");
+		ret = -ENOMEM;
+	}
+
+error:
+	pci_dev_put(pdev);
+	return ret;
+}
+
+static int hyperv_setup_gen2(struct hyperv_drm_device *hv,
+			     struct hv_device *hdev)
+{
+	struct drm_device *dev = &hv->dev;
+	int ret;
+
+	drm_aperture_remove_conflicting_framebuffers(screen_info.lfb_base,
+						     screen_info.lfb_size,
+						     false,
+						     "hypervdrmfb");
+
+	hv->fb_size = (unsigned long)hv->mmio_megabytes * 1024 * 1024;
+
+	ret = vmbus_allocate_mmio(&hv->mem, hdev, 0, -1, hv->fb_size, 0x100000,
+				  true);
+	if (ret) {
+		drm_err(dev, "Failed to allocate mmio\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * Map the VRAM cacheable for performance. This is also required for VM
+	 * connect to display properly for ARM64 Linux VM, as the host also maps
+	 * the VRAM cacheable.
+	 */
+	hv->vram = ioremap_cache(hv->mem->start, hv->fb_size);
+	if (!hv->vram) {
+		drm_err(dev, "Failed to map vram\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	hv->fb_base = hv->mem->start;
+	return 0;
+
+error:
+	vmbus_free_mmio(hv->mem->start, hv->fb_size);
+	return ret;
+}
+
+static int hyperv_vmbus_probe(struct hv_device *hdev,
+			      const struct hv_vmbus_device_id *dev_id)
+{
+	struct hyperv_drm_device *hv;
+	struct drm_device *dev;
+	int ret;
+
+	hv = devm_drm_dev_alloc(&hdev->device, &hyperv_driver,
+				struct hyperv_drm_device, dev);
+	if (IS_ERR(hv))
+		return PTR_ERR(hv);
+
+	dev = &hv->dev;
+	init_completion(&hv->wait);
+	hv_set_drvdata(hdev, hv);
+	hv->hdev = hdev;
+
+	ret = hyperv_connect_vsp(hdev);
+	if (ret) {
+		drm_err(dev, "Failed to connect to vmbus.\n");
+		goto err_hv_set_drv_data;
+	}
+
+	if (efi_enabled(EFI_BOOT))
+		ret = hyperv_setup_gen2(hv, hdev);
+	else
+		ret = hyperv_setup_gen1(hv);
+
+	if (ret)
+		goto err_vmbus_close;
+
+	/*
+	 * Should be done only once during init and resume. Failing to update
+	 * vram location is not fatal. Device will update dirty area till
+	 * preferred resolution only.
+	 */
+	ret = hyperv_update_vram_location(hdev, hv->fb_base);
+	if (ret)
+		drm_warn(dev, "Failed to update vram location.\n");
+
+	hv->dirt_needed = true;
+
+	ret = hyperv_mode_config_init(hv);
+	if (ret)
+		goto err_vmbus_close;
+
+	ret = drm_dev_register(dev, 0);
+	if (ret) {
+		drm_err(dev, "Failed to register drm driver.\n");
+		goto err_vmbus_close;
+	}
+
+	drm_fbdev_generic_setup(dev, 0);
+
+	return 0;
+
+err_vmbus_close:
+	vmbus_close(hdev->channel);
+err_hv_set_drv_data:
+	hv_set_drvdata(hdev, NULL);
+	return ret;
+}
+
+static int hyperv_vmbus_remove(struct hv_device *hdev)
+{
+	struct drm_device *dev = hv_get_drvdata(hdev);
+	struct hyperv_drm_device *hv = to_hv(dev);
+
+	drm_dev_unplug(dev);
+	drm_atomic_helper_shutdown(dev);
+	vmbus_close(hdev->channel);
+	hv_set_drvdata(hdev, NULL);
+	vmbus_free_mmio(hv->mem->start, hv->fb_size);
+
+	return 0;
+}
+
+static int hyperv_vmbus_suspend(struct hv_device *hdev)
+{
+	struct drm_device *dev = hv_get_drvdata(hdev);
+	int ret;
+
+	ret = drm_mode_config_helper_suspend(dev);
+	if (ret)
+		return ret;
+
+	vmbus_close(hdev->channel);
+
+	return 0;
+}
+
+static int hyperv_vmbus_resume(struct hv_device *hdev)
+{
+	struct drm_device *dev = hv_get_drvdata(hdev);
+	struct hyperv_drm_device *hv = to_hv(dev);
+	int ret;
+
+	ret = hyperv_connect_vsp(hdev);
+	if (ret)
+		return ret;
+
+	ret = hyperv_update_vram_location(hdev, hv->fb_base);
+	if (ret)
+		return ret;
+
+	return drm_mode_config_helper_resume(dev);
+}
+
+static const struct hv_vmbus_device_id hyperv_vmbus_tbl[] = {
+	/* Synthetic Video Device GUID */
+	{HV_SYNTHVID_GUID},
+	{}
+};
+
+static struct hv_driver hyperv_hv_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = hyperv_vmbus_tbl,
+	.probe = hyperv_vmbus_probe,
+	.remove = hyperv_vmbus_remove,
+	.suspend = hyperv_vmbus_suspend,
+	.resume = hyperv_vmbus_resume,
+	.driver = {
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+
+static int __init hyperv_init(void)
+{
+	int ret;
+
+	ret = pci_register_driver(&hyperv_pci_driver);
+	if (ret != 0)
+		return ret;
+
+	return vmbus_driver_register(&hyperv_hv_driver);
+}
+
+static void __exit hyperv_exit(void)
+{
+	vmbus_driver_unregister(&hyperv_hv_driver);
+	pci_unregister_driver(&hyperv_pci_driver);
+}
+
+module_init(hyperv_init);
+module_exit(hyperv_exit);
+
+MODULE_DEVICE_TABLE(pci, hyperv_pci_tbl);
+MODULE_DEVICE_TABLE(vmbus, hyperv_vmbus_tbl);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Deepak Rawat <drawat.floss@gmail.com>");
+MODULE_DESCRIPTION("DRM driver for Hyper-V synthetic video device");