/*
 * Virtualized GPU
 *
 * Copyright (c) 2014-2015, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/pm_runtime.h>
#include "vgpu/vgpu.h"
#include "gk20a/debug_gk20a.h"
#include "gk20a/hal_gk20a.h"
#include "gk20a/hw_mc_gk20a.h"

static inline int vgpu_comm_init(struct platform_device *pdev)
{
	size_t queue_sizes[] = { TEGRA_VGPU_QUEUE_SIZES };

	return tegra_gr_comm_init(pdev, TEGRA_GR_COMM_CTX_CLIENT, 3,
				queue_sizes, TEGRA_VGPU_QUEUE_CMD,
				ARRAY_SIZE(queue_sizes));
}

static inline void vgpu_comm_deinit(void)
{
	size_t queue_sizes[] = { TEGRA_VGPU_QUEUE_SIZES };

	tegra_gr_comm_deinit(TEGRA_GR_COMM_CTX_CLIENT, TEGRA_VGPU_QUEUE_CMD,
			ARRAY_SIZE(queue_sizes));
}

int vgpu_comm_sendrecv(struct tegra_vgpu_cmd_msg *msg, size_t size_in,
		size_t size_out)
{
	void *handle;
	size_t size = size_in;
	void *data = msg;
	int err;

	err = tegra_gr_comm_sendrecv(TEGRA_GR_COMM_CTX_CLIENT,
				tegra_gr_comm_get_server_vmid(),
				TEGRA_VGPU_QUEUE_CMD, &handle, &data, &size);
	if (!err) {
		WARN_ON(size < size_out);
		memcpy(msg, data, size_out);
		tegra_gr_comm_release(handle);
	}

	return err;
}

static u64 vgpu_connect(void)
{
	struct tegra_vgpu_cmd_msg msg;
	struct tegra_vgpu_connect_params *p = &msg.params.connect;
	int err;

	msg.cmd = TEGRA_VGPU_CMD_CONNECT;
	p->module = TEGRA_VGPU_MODULE_GPU;
	err = vgpu_comm_sendrecv(&msg, sizeof(msg), sizeof(msg));

	return (err || msg.ret) ? 0 : p->handle;
}

int vgpu_get_attribute(u64 handle, u32 attrib, u32 *value)
{
	struct tegra_vgpu_cmd_msg msg;
	struct tegra_vgpu_attrib_params *p = &msg.params.attrib;
	int err;

	msg.cmd = TEGRA_VGPU_CMD_GET_ATTRIBUTE;
	msg.handle = handle;
	p->attrib = attrib;
	err = vgpu_comm_sendrecv(&msg, sizeof(msg), sizeof(msg));

	if (err || msg.ret)
		return -1;

	*value = p->value;
	return 0;
}

static int vgpu_intr_thread(void *dev_id)
{
	struct gk20a *g = dev_id;

	while (true) {
		struct tegra_vgpu_intr_msg *msg;
		u32 sender;
		void *handle;
		size_t size;
		int err;

		err = tegra_gr_comm_recv(TEGRA_GR_COMM_CTX_CLIENT,
					TEGRA_VGPU_QUEUE_INTR, &handle,
					(void **)&msg, &size, &sender);
		if (WARN_ON(err))
			continue;

		if (msg->event == TEGRA_VGPU_EVENT_ABORT) {
			tegra_gr_comm_release(handle);
			break;
		}

		if (msg->unit == TEGRA_VGPU_INTR_GR)
			vgpu_gr_isr(g, &msg->info.gr_intr);
		else if (msg->unit == TEGRA_VGPU_NONSTALL_INTR_GR)
			vgpu_gr_nonstall_isr(g, &msg->info.gr_nonstall_intr);
		else if (msg->unit == TEGRA_VGPU_INTR_FIFO)
			vgpu_fifo_isr(g, &msg->info.fifo_intr);
		else if (msg->unit == TEGRA_VGPU_NONSTALL_INTR_FIFO)
			vgpu_fifo_nonstall_isr(g,
					&msg->info.fifo_nonstall_intr);
		else if (msg->unit == TEGRA_VGPU_NONSTALL_INTR_CE2)
			vgpu_ce2_nonstall_isr(g, &msg->info.ce2_nonstall_intr);

		tegra_gr_comm_release(handle);
	}

	while (!kthread_should_stop())
		msleep(10);
	return 0;
}

static void vgpu_remove_support(struct platform_device *dev)
{
	struct gk20a *g = get_gk20a(dev);
	struct gk20a_platform *platform = gk20a_get_platform(dev);
	struct tegra_vgpu_intr_msg msg;
	int err;

	if (g->pmu.remove_support)
		g->pmu.remove_support(&g->pmu);

	if (g->gr.remove_support)
		g->gr.remove_support(&g->gr);

	if (g->fifo.remove_support)
		g->fifo.remove_support(&g->fifo);

	if (g->mm.remove_support)
		g->mm.remove_support(&g->mm);

	msg.event = TEGRA_VGPU_EVENT_ABORT;
	err = tegra_gr_comm_send(TEGRA_GR_COMM_CTX_CLIENT,
				TEGRA_GR_COMM_ID_SELF, TEGRA_VGPU_QUEUE_INTR,
				&msg, sizeof(msg));
	WARN_ON(err);
	kthread_stop(platform->intr_handler);

	/* free mappings to registers, etc*/

	if (g->bar1) {
		iounmap(g->bar1);
		g->bar1 = 0;
	}
}

static int vgpu_init_support(struct platform_device *dev)
{
	struct resource *r = platform_get_resource(dev, IORESOURCE_MEM, 0);
	struct gk20a *g = get_gk20a(dev);
	int err = 0;

	if (!r) {
		dev_err(dev_from_gk20a(g), "faield to get gk20a bar1\n");
		err = -ENXIO;
		goto fail;
	}

	g->bar1 = devm_ioremap_resource(&dev->dev, r);
	if (IS_ERR(g->bar1)) {
		dev_err(dev_from_gk20a(g), "failed to remap gk20a bar1\n");
		err = PTR_ERR(g->bar1);
		goto fail;
	}

	mutex_init(&g->dbg_sessions_lock);
	mutex_init(&g->client_lock);

	g->remove_support = vgpu_remove_support;
	return 0;

 fail:
	vgpu_remove_support(dev);
	return err;
}

int vgpu_pm_prepare_poweroff(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct gk20a *g = get_gk20a(pdev);
	int ret = 0;

	gk20a_dbg_fn("");

	if (!g->power_on)
		return 0;

	ret = gk20a_channel_suspend(g);
	if (ret)
		return ret;

	g->power_on = false;

	return ret;
}

static void vgpu_detect_chip(struct gk20a *g)
{
	struct nvgpu_gpu_characteristics *gpu = &g->gpu_characteristics;
	struct gk20a_platform *platform = gk20a_get_platform(g->dev);

	u32 mc_boot_0_value;

	if (vgpu_get_attribute(platform->virt_handle,
			TEGRA_VGPU_ATTRIB_PMC_BOOT_0,
			&mc_boot_0_value)) {
		gk20a_err(dev_from_gk20a(g), "failed to detect chip");
		return;
	}

	gpu->arch = mc_boot_0_architecture_v(mc_boot_0_value) <<
		NVGPU_GPU_ARCHITECTURE_SHIFT;
	gpu->impl = mc_boot_0_implementation_v(mc_boot_0_value);
	gpu->rev =
		(mc_boot_0_major_revision_v(mc_boot_0_value) << 4) |
		mc_boot_0_minor_revision_v(mc_boot_0_value);

	gk20a_dbg_info("arch: %x, impl: %x, rev: %x\n",
			g->gpu_characteristics.arch,
			g->gpu_characteristics.impl,
			g->gpu_characteristics.rev);
}

static int vgpu_init_hal(struct gk20a *g)
{
	u32 ver = g->gpu_characteristics.arch + g->gpu_characteristics.impl;

	switch (ver) {
	case GK20A_GPUID_GK20A:
		gk20a_dbg_info("gk20a detected");
		/* init gk20a ops then override with virt extensions */
		gk20a_init_hal(g);
		vgpu_init_fifo_ops(&g->ops);
		vgpu_init_gr_ops(&g->ops);
		vgpu_init_ltc_ops(&g->ops);
		vgpu_init_mm_ops(&g->ops);
		vgpu_init_debug_ops(&g->ops);
		break;
	default:
		gk20a_err(&g->dev->dev, "no support for %x", ver);
		return -ENODEV;
	}

	return 0;
}

int vgpu_pm_finalize_poweron(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct gk20a *g = get_gk20a(pdev);
	int err;

	gk20a_dbg_fn("");

	if (g->power_on)
		return 0;

	g->power_on = true;

	vgpu_detect_chip(g);
	err = vgpu_init_hal(g);
	if (err)
		goto done;

	err = vgpu_init_mm_support(g);
	if (err) {
		gk20a_err(dev, "failed to init gk20a mm");
		goto done;
	}

	err = vgpu_init_fifo_support(g);
	if (err) {
		gk20a_err(dev, "failed to init gk20a fifo");
		goto done;
	}

	err = vgpu_init_gr_support(g);
	if (err) {
		gk20a_err(dev, "failed to init gk20a gr");
		goto done;
	}

	err = gk20a_init_gpu_characteristics(g);
	if (err) {
		gk20a_err(dev, "failed to init gk20a gpu characteristics");
		goto done;
	}

	gk20a_channel_resume(g);

done:
	return err;
}

static int vgpu_pm_initialise_domain(struct platform_device *pdev)
{
	struct gk20a_platform *platform = platform_get_drvdata(pdev);
	struct dev_power_governor *pm_domain_gov = NULL;
	struct gk20a_domain_data *vgpu_pd_data;
	struct generic_pm_domain *domain;

	vgpu_pd_data = (struct gk20a_domain_data *)kzalloc
		(sizeof(struct gk20a_domain_data), GFP_KERNEL);

	if (!vgpu_pd_data)
		return -ENOMEM;

	domain = &vgpu_pd_data->gpd;
	vgpu_pd_data->gk20a = platform->g;

	domain->name = "gpu";

#ifdef CONFIG_PM_RUNTIME
	pm_domain_gov = &pm_domain_always_on_gov;
#endif

	pm_genpd_init(domain, pm_domain_gov, true);

	domain->dev_ops.save_state = vgpu_pm_prepare_poweroff;
	domain->dev_ops.restore_state = vgpu_pm_finalize_poweron;

	device_set_wakeup_capable(&pdev->dev, 0);
	return pm_genpd_add_device(domain, &pdev->dev);
}

static int vgpu_pm_init(struct platform_device *dev)
{
	int err = 0;

	gk20a_dbg_fn("");

	pm_runtime_enable(&dev->dev);

	/* genpd will take care of runtime power management if it is enabled */
	if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS))
		err = vgpu_pm_initialise_domain(dev);

	return err;
}

int vgpu_probe(struct platform_device *dev)
{
	struct gk20a *gk20a;
	int err;
	struct gk20a_platform *platform = gk20a_get_platform(dev);

	if (!platform) {
		dev_err(&dev->dev, "no platform data\n");
		return -ENODATA;
	}

	gk20a_dbg_fn("");

	gk20a = kzalloc(sizeof(struct gk20a), GFP_KERNEL);
	if (!gk20a) {
		dev_err(&dev->dev, "couldn't allocate gk20a support");
		return -ENOMEM;
	}

	platform->g = gk20a;
	gk20a->dev = dev;

	err = gk20a_user_init(dev);
	if (err)
		return err;

	vgpu_init_support(dev);

	init_rwsem(&gk20a->busy_lock);

	spin_lock_init(&gk20a->mc_enable_lock);

	/* Initialize the platform interface. */
	err = platform->probe(dev);
	if (err) {
		dev_err(&dev->dev, "platform probe failed");
		return err;
	}

	err = vgpu_pm_init(dev);
	if (err) {
		dev_err(&dev->dev, "pm init failed");
		return err;
	}

	if (platform->late_probe) {
		err = platform->late_probe(dev);
		if (err) {
			dev_err(&dev->dev, "late probe failed");
			return err;
		}
	}

	err = vgpu_comm_init(dev);
	if (err) {
		dev_err(&dev->dev, "failed to init comm interface\n");
		return -ENOSYS;
	}

	platform->virt_handle = vgpu_connect();
	if (!platform->virt_handle) {
		dev_err(&dev->dev, "failed to connect to server node\n");
		vgpu_comm_deinit();
		return -ENOSYS;
	}

	platform->intr_handler = kthread_run(vgpu_intr_thread, gk20a, "gk20a");
	if (IS_ERR(platform->intr_handler))
		return -ENOMEM;

	gk20a_debug_init(dev);

	/* Set DMA parameters to allow larger sgt lists */
	dev->dev.dma_parms = &gk20a->dma_parms;
	dma_set_max_seg_size(&dev->dev, UINT_MAX);

	gk20a->gr_idle_timeout_default =
			CONFIG_GK20A_DEFAULT_TIMEOUT;
	gk20a->timeouts_enabled = true;

	gk20a_create_sysfs(dev);
	gk20a_init_gr(gk20a);

	return 0;
}

int vgpu_remove(struct platform_device *dev)
{
	struct gk20a *g = get_gk20a(dev);
	struct gk20a_domain_data *vgpu_gpd;
	gk20a_dbg_fn("");

	if (g->remove_support)
		g->remove_support(dev);

	vgpu_gpd = container_of(&g, struct gk20a_domain_data, gk20a);
	vgpu_gpd->gk20a = NULL;
	kfree(vgpu_gpd);

	vgpu_comm_deinit();
	gk20a_user_deinit(dev);
	gk20a_get_platform(dev)->g = NULL;
	kfree(g);
	return 0;
}