drm/tegra: Support virtualized engines

Support engines that are not owned by NvHost Server.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Change-Id: I3d3c8b153e1e5c92bcf6d9e1439c20fba3b9767f
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2811838
Reviewed-by: svc_kernel_abi <svc_kernel_abi@nvidia.com>
Reviewed-by: Jonathan Hunter <jonathanh@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/gpu/drm/tegra/Makefile

@@ -35,7 +35,8 @@ tegra-drm-next-y := \
 	nvjpg.o \
 	riscv.o \
 	util.o \
-	ofa.o
+	ofa.o \
+	virt.o
 
 tegra-drm-next-y += trace.o
 

drivers/gpu/drm/tegra/drm.c

@@ -1402,6 +1402,7 @@ static const struct of_device_id host1x_drm_subdevs[] = {
 	{ .compatible = "nvidia,tegra234-nvenc", },
 	{ .compatible = "nvidia,tegra234-nvjpg", },
 	{ .compatible = "nvidia,tegra234-ofa", },
+	{ .compatible = "nvidia,tegra234-host1x-virtual-engine", },
 	{ /* sentinel */ }
 };
 
@@ -1429,6 +1430,7 @@ static struct platform_driver * const drivers[] = {
 	&tegra_nvenc_driver,
 	&tegra_nvjpg_driver,
 	&tegra_ofa_driver,
+	&tegra_virt_engine_driver,
 };
 
 static int __init host1x_drm_init(void)

drivers/gpu/drm/tegra/drm.h

@@ -217,5 +217,6 @@ extern struct platform_driver tegra_nvdec_driver;
 extern struct platform_driver tegra_nvenc_driver;
 extern struct platform_driver tegra_nvjpg_driver;
 extern struct platform_driver tegra_ofa_driver;
+extern struct platform_driver tegra_virt_engine_driver;
 
 #endif /* HOST1X_DRM_H */

drivers/gpu/drm/tegra/submit.c

@@ -517,8 +517,10 @@ static void release_job(struct host1x_job *job)
 	kfree(job_data->used_mappings);
 	kfree(job_data);
 
+	if (pm_runtime_enabled(client->base.dev)) {
 		pm_runtime_mark_last_busy(client->base.dev);
 		pm_runtime_put_autosuspend(client->base.dev);
+	}
 }
 
 int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
@@ -646,12 +648,14 @@ int tegra_drm_ioctl_channel_submit(struct drm_device *drm, void *data,
 #endif
 	}
 
-	/* Boot engine. */
+	/* Boot engine, if necessary. */
+	if (pm_runtime_enabled(context->client->base.dev)) {
 		err = pm_runtime_resume_and_get(context->client->base.dev);
 		if (err < 0) {
 			SUBMIT_ERR(context, "could not power up engine: %d", err);
 			goto put_memory_context;
 		}
+	}
 
 	job->user_data = job_data;
 	job->release = release_job;

drivers/gpu/drm/tegra/virt.c

@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022, NVIDIA Corporation.
+ */
+
+#include <linux/host1x-next.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/version.h>
+
+#include <soc/tegra/virt/hv-ivc.h>
+
+#include "drm.h"
+
+#define TEGRA_VHOST_CMD_CONNECT			0
+#define TEGRA_VHOST_CMD_DISCONNECT		1
+#define TEGRA_VHOST_CMD_SUSPEND			2
+#define TEGRA_VHOST_CMD_RESUME			3
+#define TEGRA_VHOST_CMD_GET_CONNECTION_ID	4
+
+struct tegra_vhost_connect_params {
+	u32 module;
+	u64 connection_id;
+};
+
+struct tegra_vhost_cmd_msg {
+	u32 cmd;
+	int ret;
+	u64 connection_id;
+	struct tegra_vhost_connect_params connect;
+};
+
+struct virt_engine {
+	struct device *dev;
+	struct tegra_hv_ivc_cookie *cookie;
+	int connection_id;
+
+	struct tegra_drm_client client;
+};
+
+static inline struct virt_engine *to_virt_engine(struct tegra_drm_client *client)
+{
+	return container_of(client, struct virt_engine, client);
+}
+
+static int virt_engine_init(struct host1x_client *client)
+{
+	struct tegra_drm_client *drm = host1x_to_drm_client(client);
+	struct drm_device *dev = dev_get_drvdata(client->host);
+	struct tegra_drm *tegra = dev->dev_private;
+	int err;
+
+	err = tegra_drm_register_client(tegra, drm);
+	if (err < 0)
+		return err;
+
+	/*
+	 * Inherit the DMA parameters (such as maximum segment size) from the
+	 * parent host1x device.
+	 */
+	client->dev->dma_parms = client->host->dma_parms;
+
+	return 0;
+}
+
+static int virt_engine_exit(struct host1x_client *client)
+{
+	struct tegra_drm_client *drm = host1x_to_drm_client(client);
+	struct drm_device *dev = dev_get_drvdata(client->host);
+	struct tegra_drm *tegra = dev->dev_private;
+	int err;
+
+	/* avoid a dangling pointer just in case this disappears */
+	client->dev->dma_parms = NULL;
+
+	err = tegra_drm_unregister_client(tegra, drm);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static const struct host1x_client_ops virt_engine_client_ops = {
+	.init = virt_engine_init,
+	.exit = virt_engine_exit,
+};
+
+static int virt_engine_open_channel(struct tegra_drm_client *client,
+				    struct tegra_drm_context *context)
+{
+	return -EINVAL;
+}
+
+static void virt_engine_close_channel(struct tegra_drm_context *context)
+{
+}
+
+static int virt_engine_can_use_memory_ctx(struct tegra_drm_client *client, bool *supported)
+{
+	*supported = true;
+
+	return 0;
+}
+
+static const struct tegra_drm_client_ops virt_engine_ops = {
+	.open_channel = virt_engine_open_channel,
+	.close_channel = virt_engine_close_channel,
+	.submit = tegra_drm_submit,
+	.get_streamid_offset = tegra_drm_get_streamid_offset_thi,
+	.can_use_memory_ctx = virt_engine_can_use_memory_ctx,
+};
+
+static int virt_engine_setup_ivc(struct virt_engine *virt)
+{
+	struct device_node *host1x_dn = virt->dev->parent->of_node;
+	struct device_node *hv;
+	u32 ivc_instance;
+	int err;
+
+	hv = of_parse_phandle(host1x_dn, "nvidia,server-ivc", 0);
+	if (!hv) {
+		dev_err(virt->dev, "nvidia,server-ivc not configured\n");
+		return -EINVAL;
+	}
+
+	err = of_property_read_u32_index(host1x_dn, "nvidia,server-ivc", 1, &ivc_instance);
+	if (err) {
+		dev_err(virt->dev, "nvidia,server-ivc not configured\n");
+		return -EINVAL;
+	}
+
+	virt->cookie = tegra_hv_ivc_reserve(hv, ivc_instance, NULL);
+	if (IS_ERR(virt->cookie)) {
+		dev_err(virt->dev, "IVC channel reservation failed: %ld\n", PTR_ERR(virt->cookie));
+		return PTR_ERR(virt->cookie);
+	}
+
+	tegra_hv_ivc_channel_reset(virt->cookie);
+
+	while (tegra_hv_ivc_channel_notified(virt->cookie))
+		;
+
+	return 0;
+}
+
+static int virt_engine_transfer(struct virt_engine *virt, void *data, u32 size)
+{
+	int err;
+
+	while (!tegra_hv_ivc_can_write(virt->cookie))
+		;
+
+	err = tegra_hv_ivc_write(virt->cookie, data, size);
+	if (err != size)
+		return -ENOMEM;
+
+	while (!tegra_hv_ivc_can_read(virt->cookie))
+		;
+
+	err = tegra_hv_ivc_read(virt->cookie, data, size);
+	if (err != size)
+		return -EIO;
+
+	return 0;
+}
+
+static int virt_engine_connect(struct virt_engine *virt, u32 module_id)
+{
+	struct tegra_vhost_cmd_msg msg = { 0 };
+	int err;
+
+	msg.cmd = TEGRA_VHOST_CMD_CONNECT;
+	msg.connect.module = module_id;
+
+	err = virt_engine_transfer(virt, &msg, sizeof(msg));
+	if (err < 0)
+		return err;
+
+	return msg.connect.connection_id;
+}
+
+static int virt_engine_suspend(struct device *dev)
+{
+	struct virt_engine *virt = dev_get_drvdata(dev);
+	struct tegra_vhost_cmd_msg msg = { 0 };
+
+	msg.cmd = TEGRA_VHOST_CMD_SUSPEND;
+	msg.connection_id = virt->connection_id;
+
+	return virt_engine_transfer(virt, &msg, sizeof(msg));
+}
+
+static int virt_engine_resume(struct device *dev)
+{
+	struct virt_engine *virt = dev_get_drvdata(dev);
+	struct tegra_vhost_cmd_msg msg = { 0 };
+
+	msg.cmd = TEGRA_VHOST_CMD_RESUME;
+	msg.connection_id = virt->connection_id;
+
+	return virt_engine_transfer(virt, &msg, sizeof(msg));
+}
+
+static const struct of_device_id tegra_virt_engine_of_match[] = {
+	{ .compatible = "nvidia,tegra234-host1x-virtual-engine" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_virt_engine_of_match);
+
+static int virt_engine_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	u32 module_id, class;
+	struct virt_engine *virt;
+	int err;
+
+	err = of_property_read_u32(pdev->dev.of_node, "nvidia,module-id", &module_id);
+	if (err < 0) {
+		dev_err(dev, "could not read property nvidia,module-id: %d\n", err);
+		return err;
+	}
+
+	err = of_property_read_u32(pdev->dev.of_node, "nvidia,class", &class);
+	if (err < 0) {
+		dev_err(dev, "could not read property nvidia,class: %d\n", err);
+		return err;
+	}
+
+	/* inherit DMA mask from host1x parent */
+	err = dma_coerce_mask_and_coherent(dev, *dev->parent->dma_mask);
+	if (err < 0) {
+		dev_err(dev, "failed to set DMA mask: %d\n", err);
+		return err;
+	}
+
+	virt = devm_kzalloc(dev, sizeof(*virt), GFP_KERNEL);
+	if (!virt)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, virt);
+
+	INIT_LIST_HEAD(&virt->client.base.list);
+	virt->client.base.ops = &virt_engine_client_ops;
+	virt->client.base.dev = dev;
+	virt->client.base.class = class;
+	virt->client.base.syncpts = NULL;
+	virt->client.base.num_syncpts = 0;
+	virt->dev = dev;
+
+	INIT_LIST_HEAD(&virt->client.list);
+	virt->client.version = 0x23;
+	virt->client.ops = &virt_engine_ops;
+
+	err = host1x_client_register(&virt->client.base);
+	if (err < 0) {
+		dev_err(dev, "failed to register host1x client: %d\n", err);
+		return err;
+	}
+
+	err = virt_engine_setup_ivc(virt);
+	if (err < 0)
+		goto unregister_client;
+
+	/* Connect to HOST module. This doesn't really do anything but we need to do it first. */
+	virt_engine_connect(virt, 1);
+
+	virt->connection_id = virt_engine_connect(virt, module_id);
+	if (virt->connection_id < 0) {
+		dev_err(dev, "failed to register with server\n");
+		err = -EIO;
+		goto cleanup_ivc;
+	}
+
+	return 0;
+
+cleanup_ivc:
+	tegra_hv_ivc_unreserve(virt->cookie);
+unregister_client:
+	host1x_client_unregister(&virt->client.base);
+
+	return err;
+}
+
+static int virt_engine_remove(struct platform_device *pdev)
+{
+	struct virt_engine *virt_engine = platform_get_drvdata(pdev);
+	int err;
+
+	tegra_hv_ivc_unreserve(virt_engine->cookie);
+
+	err = host1x_client_unregister(&virt_engine->client.base);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to unregister host1x client: %d\n",
+			err);
+		return err;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops virt_engine_pm_ops = {
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 17, 0)
+	SYSTEM_SLEEP_PM_OPS(virt_engine_suspend, virt_engine_resume)
+#else
+	SET_SYSTEM_SLEEP_PM_OPS(virt_engine_suspend, virt_engine_resume)
+#endif
+};
+
+struct platform_driver tegra_virt_engine_driver = {
+	.driver = {
+		.name = "tegra-host1x-virtual-engine",
+		.of_match_table = tegra_virt_engine_of_match,
+		.pm = &virt_engine_pm_ops,
+	},
+	.probe = virt_engine_probe,
+	.remove = virt_engine_remove,
+};