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>

#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
#include <asm/dma-iommu.h>
#endif

#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 int tegra_atomic_check(struct drm_device *drm,
			      struct drm_atomic_state *state)
{
	int err;

	err = drm_atomic_helper_check(drm, state);
	if (err < 0)
		return err;

	return tegra_display_hub_atomic_check(drm, state);
}

static const struct drm_mode_config_funcs tegra_drm_mode_config_funcs = {
	.fb_create = tegra_fb_create,
#ifdef CONFIG_DRM_FBDEV_EMULATION
	.output_poll_changed = drm_fb_helper_output_poll_changed,
#endif
	.atomic_check = tegra_atomic_check,
	.atomic_commit = drm_atomic_helper_commit,
};

static void tegra_atomic_commit_tail(struct drm_atomic_state *old_state)
{
	struct drm_device *drm = old_state->dev;
	struct tegra_drm *tegra = drm->dev_private;

	if (tegra->hub) {
		drm_atomic_helper_commit_modeset_disables(drm, old_state);
		tegra_display_hub_atomic_commit(drm, old_state);
		drm_atomic_helper_commit_planes(drm, old_state, 0);
		drm_atomic_helper_commit_modeset_enables(drm, old_state);
		drm_atomic_helper_commit_hw_done(old_state);
		drm_atomic_helper_wait_for_vblanks(drm, old_state);
		drm_atomic_helper_cleanup_planes(drm, old_state);
	} else {
		drm_atomic_helper_commit_tail_rpm(old_state);
	}
}

static const struct drm_mode_config_helper_funcs
tegra_drm_mode_config_helpers = {
	.atomic_commit_tail = tegra_atomic_commit_tail,
};

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

		err = iova_cache_get();
		if (err < 0)
			goto domain;
	}

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

	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.normalize_zpos = true;

	drm->mode_config.funcs = &tegra_drm_mode_config_funcs;
	drm->mode_config.helper_private = &tegra_drm_mode_config_helpers;

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

	drm_kms_helper_poll_init(drm);

	err = host1x_device_init(device);
	if (err < 0)
		goto fbdev;

	if (tegra->domain) {
		u64 carveout_start, carveout_end, gem_start, gem_end;
		dma_addr_t start, end;
		unsigned long order;

		start = tegra->domain->geometry.aperture_start;
		end = tegra->domain->geometry.aperture_end;

		gem_start = start;
		gem_end = end - CARVEOUT_SZ;
		carveout_start = gem_end + 1;
		carveout_end = end;

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

	if (tegra->hub) {
		err = tegra_display_hub_prepare(tegra->hub);
		if (err < 0)
			goto device;
	}

	/*
	 * We don't use the drm_irq_install() helpers provided by the DRM
	 * core, so we need to set this manually in order to allow the
	 * DRM_IOCTL_WAIT_VBLANK to operate correctly.
	 */
	drm->irq_enabled = true;

	/* syncpoints are used for full 32-bit hardware VBLANK counters */
	drm->max_vblank_count = 0xffffffff;

	err = drm_vblank_init(drm, drm->mode_config.num_crtc);
	if (err < 0)
		goto hub;

	drm_mode_config_reset(drm);

	err = tegra_drm_fb_init(drm);
	if (err < 0)
		goto hub;

	return 0;

hub:
	if (tegra->hub)
		tegra_display_hub_cleanup(tegra->hub);
device:
	host1x_device_exit(device);
fbdev:
	drm_kms_helper_poll_fini(drm);