drm.c

/*
 * Copyright (C) 2012 Avionic Design GmbH
 * Copyright (C) 2012-2016 NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bitops.h>
#include <linux/host1x.h>
#include <linux/idr.h>
#include <linux/iommu.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>

#include "drm.h"
#include "gem.h"

#define DRIVER_NAME "tegra"
#define DRIVER_DESC "NVIDIA Tegra graphics"
#define DRIVER_DATE "20120330"
#define DRIVER_MAJOR 0
#define DRIVER_MINOR 0
#define DRIVER_PATCHLEVEL 0

#define CARVEOUT_SZ SZ_64M
#define CDMA_GATHER_FETCHES_MAX_NB 16383

struct tegra_drm_file {
	struct idr contexts;
	struct mutex lock;
};

static void tegra_atomic_schedule(struct tegra_drm *tegra,
				  struct drm_atomic_state *state)
{
	tegra->commit.state = state;
	schedule_work(&tegra->commit.work);
}

static void tegra_atomic_complete(struct tegra_drm *tegra,
				  struct drm_atomic_state *state)
{
	struct drm_device *drm = tegra->drm;

	/*
	 * Everything below can be run asynchronously without the need to grab
	 * any modeset locks at all under one condition: It must be guaranteed
	 * that the asynchronous work has either been cancelled (if the driver
	 * supports it, which at least requires that the framebuffers get
	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
	 * before the new state gets committed on the software side with
	 * drm_atomic_helper_swap_state().
	 *
	 * This scheme allows new atomic state updates to be prepared and
	 * checked in parallel to the asynchronous completion of the previous
	 * update. Which is important since compositors need to figure out the
	 * composition of the next frame right after having submitted the
	 * current layout.
	 */

	drm_atomic_helper_commit_modeset_disables(drm, state);
	drm_atomic_helper_commit_modeset_enables(drm, state);
	drm_atomic_helper_commit_planes(drm, state,
					DRM_PLANE_COMMIT_ACTIVE_ONLY);

	drm_atomic_helper_wait_for_vblanks(drm, state);

	drm_atomic_helper_cleanup_planes(drm, state);
	drm_atomic_state_put(state);
}

static void tegra_atomic_work(struct work_struct *work)
{
	struct tegra_drm *tegra = container_of(work, struct tegra_drm,
					       commit.work);

	tegra_atomic_complete(tegra, tegra->commit.state);
}

static int tegra_atomic_commit(struct drm_device *drm,
			       struct drm_atomic_state *state, bool nonblock)
{
	struct tegra_drm *tegra = drm->dev_private;
	int err;

	err = drm_atomic_helper_prepare_planes(drm, state);
	if (err)
		return err;

	/* serialize outstanding nonblocking commits */
	mutex_lock(&tegra->commit.lock);
	flush_work(&tegra->commit.work);

	/*
	 * This is the point of no return - everything below never fails except
	 * when the hw goes bonghits. Which means we can commit the new state on
	 * the software side now.
	 */

	err = drm_atomic_helper_swap_state(state, true);
	if (err) {
		mutex_unlock(&tegra->commit.lock);
		drm_atomic_helper_cleanup_planes(drm, state);
		return err;
	}

	drm_atomic_state_get(state);
	if (nonblock)
		tegra_atomic_schedule(tegra, state);
	else
		tegra_atomic_complete(tegra, state);

	mutex_unlock(&tegra->commit.lock);
	return 0;
}

static const struct drm_mode_config_funcs tegra_drm_mode_funcs = {
	.fb_create = tegra_fb_create,
#ifdef CONFIG_DRM_FBDEV_EMULATION
	.output_poll_changed = tegra_fb_output_poll_changed,
#endif
	.atomic_check = drm_atomic_helper_check,
	.atomic_commit = tegra_atomic_commit,
};

static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
{
	struct host1x_device *device = to_host1x_device(drm->dev);
	struct tegra_drm *tegra;
	int err;

	tegra = kzalloc(sizeof(*tegra), GFP_KERNEL);
	if (!tegra)
		return -ENOMEM;

	if (iommu_present(&platform_bus_type)) {
		u64 carveout_start, carveout_end, gem_start, gem_end;
		struct iommu_domain_geometry *geometry;
		unsigned long order;

		tegra->domain = iommu_domain_alloc(&platform_bus_type);
		if (!tegra->domain) {
			err = -ENOMEM;
			goto free;
		}

		geometry = &tegra->domain->geometry;
		gem_start = geometry->aperture_start;
		gem_end = geometry->aperture_end - CARVEOUT_SZ;
		carveout_start = gem_end + 1;
		carveout_end = geometry->aperture_end;

		order = __ffs(tegra->domain->pgsize_bitmap);
		init_iova_domain(&tegra->carveout.domain, 1UL << order,
				 carveout_start >> order,
				 carveout_end >> order);

		tegra->carveout.shift = iova_shift(&tegra->carveout.domain);
		tegra->carveout.limit = carveout_end >> tegra->carveout.shift;

		drm_mm_init(&tegra->mm, gem_start, gem_end - gem_start + 1);
		mutex_init(&tegra->mm_lock);

		DRM_DEBUG("IOMMU apertures:\n");
		DRM_DEBUG("  GEM: %#llx-%#llx\n", gem_start, gem_end);
		DRM_DEBUG("  Carveout: %#llx-%#llx\n", carveout_start,
			  carveout_end);
	}

	mutex_init(&tegra->clients_lock);
	INIT_LIST_HEAD(&tegra->clients);

	mutex_init(&tegra->commit.lock);
	INIT_WORK(&tegra->commit.work, tegra_atomic_work);

	drm->dev_private = tegra;
	tegra->drm = drm;

	drm_mode_config_init(drm);

	drm->mode_config.min_width = 0;
	drm->mode_config.min_height = 0;

	drm->mode_config.max_width = 4096;
	drm->mode_config.max_height = 4096;

	drm->mode_config.allow_fb_modifiers = true;

	drm->mode_config.funcs = &tegra_drm_mode_funcs;

	err = tegra_drm_fb_prepare(drm);
	if (err < 0)
		goto config;

	drm_kms_helper_poll_init(drm);

	err = host1x_device_init(device);