// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Avionic Design GmbH
 * Copyright (C) 2012-2016 NVIDIA CORPORATION.  All rights reserved.
 */

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

#include <drm/drm_aperture.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_drv.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_ioctl.h>
#include <drm/drm_prime.h>
#include <drm/drm_vblank.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 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) {
                bool fence_cookie = dma_fence_begin_signalling();

                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);
                dma_fence_end_signalling(fence_cookie);
                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_open(struct drm_device *drm, struct drm_file *filp)
{
        struct tegra_drm_file *fpriv;

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

        idr_init_base(&fpriv->contexts, 1);
        mutex_init(&fpriv->lock);
        filp->driver_priv = fpriv;

        return 0;
}

static void tegra_drm_context_free(struct tegra_drm_context *context)
{
        context->client->ops->close_channel(context);
        kfree(context);
}

static struct host1x_bo *
host1x_bo_lookup(struct drm_file *file, u32 handle)
{
        struct drm_gem_object *gem;
        struct tegra_bo *bo;

        gem = drm_gem_object_lookup(file, handle);
        if (!gem)
                return NULL;

        bo = to_tegra_bo(gem);
        return &bo->base;
}

static int host1x_reloc_copy_from_user(struct host1x_reloc *dest,
                                       struct drm_tegra_reloc __user *src,
                                       struct drm_device *drm,
                                       struct drm_file *file)
{
        u32 cmdbuf, target;
        int err;

        err = get_user(cmdbuf, &src->cmdbuf.handle);
        if (err < 0)
                return err;

        err = get_user(dest->cmdbuf.offset, &src->cmdbuf.offset);
        if (err < 0)
                return err;

        err = get_user(target, &src->target.handle);
        if (err < 0)
                return err;

        err = get_user(dest->target.offset, &src->target.offset);
        if (err < 0)
                return err;

        err = get_user(dest->shift, &src->shift);
        if (err < 0)
                return err;

        dest->flags = HOST1X_RELOC_READ | HOST1X_RELOC_WRITE;

        dest->cmdbuf.bo = host1x_bo_lookup(file, cmdbuf);
        if (!dest->cmdbuf.bo)
                return -ENOENT;

        dest->target.bo = host1x_bo_lookup(file, target);
        if (!dest->target.bo)
                return -ENOENT;

        return 0;
}

int tegra_drm_submit(struct tegra_drm_context *context,
                     struct drm_tegra_submit *args, struct drm_device *drm,
                     struct drm_file *file)
{
        struct host1x_client *client = &context->client->base;
        unsigned int num_cmdbufs = args->num_cmdbufs;
        unsigned int num_relocs = args->num_relocs;
        struct drm_tegra_cmdbuf __user *user_cmdbufs;
        struct drm_tegra_reloc __user *user_relocs;
        struct drm_tegra_syncpt __user *user_syncpt;
        struct drm_tegra_syncpt syncpt;
        struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
        struct drm_gem_object **refs;
        struct host1x_syncpt *sp = NULL;
        struct host1x_job *job;
        unsigned int num_refs;
        int err;

        user_cmdbufs = u64_to_user_ptr(args->cmdbufs);
        user_relocs = u64_to_user_ptr(args->relocs);
        user_syncpt = u64_to_user_ptr(args->syncpts);

        /* We don't yet support other than one syncpt_incr struct per submit */
        if (args->num_syncpts != 1)
                return -EINVAL;

        /* We don't yet support waitchks */
        if (args->num_waitchks != 0)
                return -EINVAL;

        job = host1x_job_alloc(context->channel, args->num_cmdbufs,
                               args->num_relocs);
        if (!job)
                return -ENOMEM;

        job->num_relocs = args->num_relocs;
        job->client = client;
        job->class = client->class;
        job->serialize = true;

        /*
         * Track referenced BOs so that they can be unreferenced after the
         * submission is complete.
         */
        num_refs = num_cmdbufs + num_relocs * 2;

        refs = kmalloc_array(num_refs, sizeof(*refs), GFP_KERNEL);
        if (!refs) {
                err = -ENOMEM;
                goto put;
        }

        /* reuse as an iterator later */
        num_refs = 0;

        while (num_cmdbufs) {
                struct drm_tegra_cmdbuf cmdbuf;
                struct host1x_bo *bo;
                struct tegra_bo *obj;
                u64 offset;

                if (copy_from_user(&cmdbuf, user_cmdbufs, sizeof(cmdbuf))) {
                        err = -EFAULT;
                        goto fail;
                }

                /*
                 * The maximum number of CDMA gather fetches is 16383, a higher
                 * value means the words count is malformed.
                 */
                if (cmdbuf.words > CDMA_GATHER_FETCHES_MAX_NB) {
                        err = -EINVAL;
                        goto fail;
                }

                bo = host1x_bo_lookup(file, cmdbuf.handle);
                if (!bo) {
                        err = -ENOENT;
                        goto fail;
                }

                offset = (u64)cmdbuf.offset + (u64)cmdbuf.words * sizeof(u32);
                obj = host1x_to_tegra_bo(bo);
                refs[num_refs++] = &obj->gem;

                /*
                 * Gather buffer base address must be 4-bytes aligned,
                 * unaligned offset is malformed and cause commands stream
                 * corruption on the buffer address relocation.
                 */
                if (offset & 3 || offset > obj->gem.size) {
                        err = -EINVAL;
                        goto fail;
                }

                host1x_job_add_gather(job, bo, cmdbuf.words, cmdbuf.offset);
                num_cmdbufs--;
                user_cmdbufs++;
        }

        /* copy and resolve relocations from submit */
        while (num_relocs--) {
                struct host1x_reloc *reloc;
                struct tegra_bo *obj;

                err = host1x_reloc_copy_from_user(&job->relocs[num_relocs],
                                                  &user_relocs[num_relocs], drm,
                                                  file);
                if (err < 0)
                        goto fail;

                reloc = &job->relocs[num_relocs];
                obj = host1x_to_tegra_bo(reloc->cmdbuf.bo);
                refs[num_refs++] = &obj->gem;

                /*
                 * The unaligned cmdbuf offset will cause an unaligned write
                 * during of the relocations patching, corrupting the commands
                 * stream.
                 */
                if (reloc->cmdbuf.offset & 3 ||
                    reloc->cmdbuf.offset >= obj->gem.size) {
                        err = -EINVAL;
                        goto fail;
                }

                obj = host1x_to_tegra_bo(reloc->target.bo);
                refs[num_refs++] = &obj->gem;

                if (reloc->target.offset >= obj->gem.size) {
                        err = -EINVAL;
                        goto fail;
                }
        }

        if (copy_from_user(&syncpt, user_syncpt, sizeof(syncpt))) {
                err = -EFAULT;
                goto fail;
        }

        /* Syncpoint ref will be dropped on job release. */
        sp = host1x_syncpt_get_by_id(host1x, syncpt.id);
        if (!sp) {
                err = -ENOENT;
                goto fail;
        }

        job->is_addr_reg = context->client->ops->is_addr_reg;
        job->is_valid_class = context->client->ops->is_valid_class;
        job->syncpt_incrs = syncpt.incrs;
        job->syncpt = sp;
        job->timeout = 10000;

        if (args->timeout && args->timeout < 10000)
                job->timeout = args->timeout;

        err = host1x_job_pin(job, context->client->base.dev);
        if (err)
                goto fail;

        err = host1x_job_submit(job);
        if (err) {
                host1x_job_unpin(job);
                goto fail;
        }

        args->fence = job->syncpt_end;

fail:
        while (num_refs--)
                drm_gem_object_put(refs[num_refs]);

        kfree(refs);

put:
        host1x_job_put(job);
        return err;
}


#ifdef CONFIG_DRM_TEGRA_STAGING
static int tegra_gem_create(struct drm_device *drm, void *data,
                            struct drm_file *file)
{
        struct drm_tegra_gem_create *args = data;
        struct tegra_bo *bo;

        bo = tegra_bo_create_with_handle(file, drm, args->size, args->flags,
                                         &args->handle);
        if (IS_ERR(bo))
                return PTR_ERR(bo);

        return 0;
}

static int tegra_gem_mmap(struct drm_device *drm, void *data,
                          struct drm_file *file)
{
        struct drm_tegra_gem_mmap *args = data;
        struct drm_gem_object *gem;
        struct tegra_bo *bo;

        gem = drm_gem_object_lookup(file, args->handle);
        if (!gem)
                return -EINVAL;

        bo = to_tegra_bo(gem);

        args->offset = drm_vma_node_offset_addr(&bo->gem.vma_node);

        drm_gem_object_put(gem);

        return 0;
}

static int tegra_syncpt_read(struct drm_device *drm, void *data,
                             struct drm_file *file)
{
        struct host1x *host = dev_get_drvdata(drm->dev->parent);
        struct drm_tegra_syncpt_read *args = data;
        struct host1x_syncpt *sp;

        sp = host1x_syncpt_get_by_id_noref(host, args->id);
        if (!sp)
                return -EINVAL;

        args->value = host1x_syncpt_read_min(sp);
        return 0;
}

static int tegra_syncpt_incr(struct drm_device *drm, void *data,
                             struct drm_file *file)
{
        struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
        struct drm_tegra_syncpt_incr *args = data;
        struct host1x_syncpt *sp;

        sp = host1x_syncpt_get_by_id_noref(host1x, args->id);
        if (!sp)
                return -EINVAL;

        return host1x_syncpt_incr(sp);
}

static int tegra_syncpt_wait(struct drm_device *drm, void *data,
                             struct drm_file *file)
{
        struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
        struct drm_tegra_syncpt_wait *args = data;
        struct host1x_syncpt *sp;

        sp = host1x_syncpt_get_by_id_noref(host1x, args->id);
        if (!sp)
                return -EINVAL;

        return host1x_syncpt_wait(sp, args->thresh,
                                  msecs_to_jiffies(args->timeout),
                                  &args->value);
}

static int tegra_client_open(struct tegra_drm_file *fpriv,
                             struct tegra_drm_client *client,
                             struct tegra_drm_context *context)
{
        int err;

        err = client->ops->open_channel(client, context);
        if (err < 0)
                return err;

        err = idr_alloc(&fpriv->contexts, context, 1, 0, GFP_KERNEL);
        if (err < 0) {
                client->ops->close_channel(context);
                return err;
        }

        context->client = client;
        context->id = err;

        return 0;
}

static int tegra_open_channel(struct drm_device *drm, void *data,
                              struct drm_file *file)
{
        struct tegra_drm_file *fpriv = file->driver_priv;
        struct tegra_drm *tegra = drm->dev_private;
        struct drm_tegra_open_channel *args = data;
        struct tegra_drm_context *context;
        struct tegra_drm_client *client;
        int err = -ENODEV;

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

        mutex_lock(&fpriv->lock);

        list_for_each_entry(client, &tegra->clients, list)
                if (client->base.class == args->client) {
                        err = tegra_client_open(fpriv, client, context);
                        if (err < 0)
                                break;

                        args->context = context->id;
                        break;
                }

        if (err < 0)
                kfree(context);

        mutex_unlock(&fpriv->lock);
        return err;
}

static int tegra_close_channel(struct drm_device *drm, void *data,
                               struct drm_file *file)
{
        struct tegra_drm_file *fpriv = file->driver_priv;
        struct drm_tegra_close_channel *args = data;
        struct tegra_drm_context *context;
        int err = 0;

        mutex_lock(&fpriv->lock);

        context = idr_find(&fpriv->contexts, args->context);
        if (!context) {
                err = -EINVAL;
                goto unlock;
        }

        idr_remove(&fpriv->contexts, context->id);
        tegra_drm_context_free(context);

unlock:
        mutex_unlock(&fpriv->lock);
        return err;
}

static int tegra_get_syncpt(struct drm_device *drm, void *data,
                            struct drm_file *file)
{
        struct tegra_drm_file *fpriv = file->driver_priv;
        struct drm_tegra_get_syncpt *args = data;
        struct tegra_drm_context *context;
        struct host1x_syncpt *syncpt;
        int err = 0;

        mutex_lock(&fpriv->lock);

        context = idr_find(&fpriv->contexts, args->context);
        if (!context) {
                err = -ENODEV;
                goto unlock;
        }

        if (args->index >= context->client->base.num_syncpts) {
                err = -EINVAL;
                goto unlock;
        }

        syncpt = context->client->base.syncpts[args->index];
        args->id = host1x_syncpt_id(syncpt);

unlock:
        mutex_unlock(&fpriv->lock);
        return err;
}

static int tegra_submit(struct drm_device *drm, void *data,
                        struct drm_file *file)
{
        struct tegra_drm_file *fpriv = file->driver_priv;
        struct drm_tegra_submit *args = data;
        struct tegra_drm_context *context;
        int err;

        mutex_lock(&fpriv->lock);

        context = idr_find(&fpriv->contexts, args->context);
        if (!context) {
                err = -ENODEV;
                goto unlock;
        }

        err = context->client->ops->submit(context, args, drm, file);

unlock:
        mutex_unlock(&fpriv->lock);
        return err;
}

static int tegra_get_syncpt_base(struct drm_device *drm, void *data,
                                 struct drm_file *file)
{
        struct tegra_drm_file *fpriv = file->driver_priv;
        struct drm_tegra_get_syncpt_base *args = data;
        struct tegra_drm_context *context;
        struct host1x_syncpt_base *base;
        struct host1x_syncpt *syncpt;
        int err = 0;

        mutex_lock(&fpriv->lock);

        context = idr_find(&fpriv->contexts, args->context);
        if (!context) {
                err = -ENODEV;
                goto unlock;
        }

        if (args->syncpt >= context->client->base.num_syncpts) {
                err = -EINVAL;
                goto unlock;
        }

        syncpt = context->client->base.syncpts[args->syncpt];

        base = host1x_syncpt_get_base(syncpt);
        if (!base) {
                err = -ENXIO;
                goto unlock;
        }

        args->id = host1x_syncpt_base_id(base);

unlock:
        mutex_unlock(&fpriv->lock);
        return err;
}

static int tegra_gem_set_tiling(struct drm_device *drm, void *data,
                                struct drm_file *file)
{
        struct drm_tegra_gem_set_tiling *args = data;
        enum tegra_bo_tiling_mode mode;
        struct drm_gem_object *gem;
        unsigned long value = 0;
        struct tegra_bo *bo;

        switch (args->mode) {
        case DRM_TEGRA_GEM_TILING_MODE_PITCH:
                mode = TEGRA_BO_TILING_MODE_PITCH;

                if (args->value != 0)
                        return -EINVAL;

                break;

        case DRM_TEGRA_GEM_TILING_MODE_TILED:
                mode = TEGRA_BO_TILING_MODE_TILED;

                if (args->value != 0)
                        return -EINVAL;

                break;

        case DRM_TEGRA_GEM_TILING_MODE_BLOCK:
                mode = TEGRA_BO_TILING_MODE_BLOCK;

                if (args->value > 5)
                        return -EINVAL;

                value = args->value;
                break;

        default:
                return -EINVAL;
        }

        gem = drm_gem_object_lookup(file, args->handle);
        if (!gem)
                return -ENOENT;

        bo = to_tegra_bo(gem);

        bo->tiling.mode = mode;
        bo->tiling.value = value;

        drm_gem_object_put(gem);

        return 0;
}

static int tegra_gem_get_tiling(struct drm_device *drm, void *data,
                                struct drm_file *file)
{
        struct drm_tegra_gem_get_tiling *args = data;
        struct drm_gem_object *gem;
        struct tegra_bo *bo;
        int err = 0;

        gem = drm_gem_object_lookup(file, args->handle);
        if (!gem)
                return -ENOENT;

        bo = to_tegra_bo(gem);

        switch (bo->tiling.mode) {
        case TEGRA_BO_TILING_MODE_PITCH:
                args->mode = DRM_TEGRA_GEM_TILING_MODE_PITCH;
                args->value = 0;
                break;

        case TEGRA_BO_TILING_MODE_TILED:
                args->mode = DRM_TEGRA_GEM_TILING_MODE_TILED;
                args->value = 0;
                break;

        case TEGRA_BO_TILING_MODE_BLOCK:
                args->mode = DRM_TEGRA_GEM_TILING_MODE_BLOCK;
                args->value = bo->tiling.value;
                break;

        default:
                err = -EINVAL;
                break;
        }

        drm_gem_object_put(gem);

        return err;
}

static int tegra_gem_set_flags(struct drm_device *drm, void *data,
                               struct drm_file *file)
{
        struct drm_tegra_gem_set_flags *args = data;
        struct drm_gem_object *gem;
        struct tegra_bo *bo;

        if (args->flags & ~DRM_TEGRA_GEM_FLAGS)
                return -EINVAL;

        gem = drm_gem_object_lookup(file, args->handle);
        if (!gem)
                return -ENOENT;

        bo = to_tegra_bo(gem);
        bo->flags = 0;

        if (args->flags & DRM_TEGRA_GEM_BOTTOM_UP)
                bo->flags |= TEGRA_BO_BOTTOM_UP;

        drm_gem_object_put(gem);

        return 0;
}

static int tegra_gem_get_flags(struct drm_device *drm, void *data,
                               struct drm_file *file)
{
        struct drm_tegra_gem_get_flags *args = data;
        struct drm_gem_object *gem;
        struct tegra_bo *bo;

        gem = drm_gem_object_lookup(file, args->handle);
        if (!gem)
                return -ENOENT;

        bo = to_tegra_bo(gem);
        args->flags = 0;

        if (bo->flags & TEGRA_BO_BOTTOM_UP)
                args->flags |= DRM_TEGRA_GEM_BOTTOM_UP;

        drm_gem_object_put(gem);

        return 0;
}
#endif

static const struct drm_ioctl_desc tegra_drm_ioctls[] = {
#ifdef CONFIG_DRM_TEGRA_STAGING
        DRM_IOCTL_DEF_DRV(TEGRA_GEM_CREATE, tegra_gem_create,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GEM_MMAP, tegra_gem_mmap,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_SYNCPT_READ, tegra_syncpt_read,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_SYNCPT_INCR, tegra_syncpt_incr,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_SYNCPT_WAIT, tegra_syncpt_wait,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_OPEN_CHANNEL, tegra_open_channel,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_CLOSE_CHANNEL, tegra_close_channel,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GET_SYNCPT, tegra_get_syncpt,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_SUBMIT, tegra_submit,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GET_SYNCPT_BASE, tegra_get_syncpt_base,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GEM_SET_TILING, tegra_gem_set_tiling,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GEM_GET_TILING, tegra_gem_get_tiling,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GEM_SET_FLAGS, tegra_gem_set_flags,
                          DRM_RENDER_ALLOW),
        DRM_IOCTL_DEF_DRV(TEGRA_GEM_GET_FLAGS, tegra_gem_get_flags,
                          DRM_RENDER_ALLOW),
#endif
};

static const struct file_operations tegra_drm_fops = {
        .owner = THIS_MODULE,
        .open = drm_open,
        .release = drm_release,
        .unlocked_ioctl = drm_ioctl,
        .mmap = tegra_drm_mmap,
        .poll = drm_poll,
        .read = drm_read,
        .compat_ioctl = drm_compat_ioctl,
        .llseek = noop_llseek,
};

static int tegra_drm_context_cleanup(int id, void *p, void *data)
{
        struct tegra_drm_context *context = p;

        tegra_drm_context_free(context);

        return 0;
}

static void tegra_drm_postclose(struct drm_device *drm, struct drm_file *file)
{
        struct tegra_drm_file *fpriv = file->driver_priv;

        mutex_lock(&fpriv->lock);
        idr_for_each(&fpriv->contexts, tegra_drm_context_cleanup, NULL);
        mutex_unlock(&fpriv->lock);

        idr_destroy(&fpriv->contexts);
        mutex_destroy(&fpriv->lock);
        kfree(fpriv);
}

#ifdef CONFIG_DEBUG_FS
static int tegra_debugfs_framebuffers(struct seq_file *s, void *data)
{
        struct drm_info_node *node = (struct drm_info_node *)s->private;
        struct drm_device *drm = node->minor->dev;
        struct drm_framebuffer *fb;

        mutex_lock(&drm->mode_config.fb_lock);

        list_for_each_entry(fb, &drm->mode_config.fb_list, head) {
                seq_printf(s, "%3d: user size: %d x %d, depth %d, %d bpp, refcount %d\n",
                           fb->base.id, fb->width, fb->height,
                           fb->format->depth,
                           fb->format->cpp[0] * 8,
                           drm_framebuffer_read_refcount(fb));
        }

        mutex_unlock(&drm->mode_config.fb_lock);

        return 0;
}

static int tegra_debugfs_iova(struct seq_file *s, void *data)
{
        struct drm_info_node *node = (struct drm_info_node *)s->private;
        struct drm_device *drm = node->minor->dev;
        struct tegra_drm *tegra = drm->dev_private;
        struct drm_printer p = drm_seq_file_printer(s);

        if (tegra->domain) {
                mutex_lock(&tegra->mm_lock);
                drm_mm_print(&tegra->mm, &p);
                mutex_unlock(&tegra->mm_lock);
        }

        return 0;
}

static struct drm_info_list tegra_debugfs_list[] = {
        { "framebuffers", tegra_debugfs_framebuffers, 0 },
        { "iova", tegra_debugfs_iova, 0 },
};

static void tegra_debugfs_init(struct drm_minor *minor)
{
        drm_debugfs_create_files(tegra_debugfs_list,
                                 ARRAY_SIZE(tegra_debugfs_list),
                                 minor->debugfs_root, minor);
}
#endif

static const struct drm_driver tegra_drm_driver = {
        .driver_features = DRIVER_MODESET | DRIVER_GEM |
                           DRIVER_ATOMIC | DRIVER_RENDER,
        .open = tegra_drm_open,
        .postclose = tegra_drm_postclose,
        .lastclose = drm_fb_helper_lastclose,

#if defined(CONFIG_DEBUG_FS)
        .debugfs_init = tegra_debugfs_init,
#endif

        .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
        .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
        .gem_prime_import = tegra_gem_prime_import,

        .dumb_create = tegra_bo_dumb_create,

        .ioctls = tegra_drm_ioctls,
        .num_ioctls = ARRAY_SIZE(tegra_drm_ioctls),
        .fops = &tegra_drm_fops,

        .name = DRIVER_NAME,
        .desc = DRIVER_DESC,
        .date = DRIVER_DATE,
        .major = DRIVER_MAJOR,
        .minor = DRIVER_MINOR,
        .patchlevel = DRIVER_PATCHLEVEL,
};

int tegra_drm_register_client(struct tegra_drm *tegra,
                              struct tegra_drm_client *client)
{
        mutex_lock(&tegra->clients_lock);
        list_add_tail(&client->list, &tegra->clients);
        client->drm = tegra;
        mutex_unlock(&tegra->clients_lock);

        return 0;
}

int tegra_drm_unregister_client(struct tegra_drm *tegra,
                                struct tegra_drm_client *client)
{
        mutex_lock(&tegra->clients_lock);
        list_del_init(&client->list);
        client->drm = NULL;
        mutex_unlock(&tegra->clients_lock);

        return 0;
}

int host1x_client_iommu_attach(struct host1x_client *client)
{
        struct iommu_domain *domain = iommu_get_domain_for_dev(client->dev);
        struct drm_device *drm = dev_get_drvdata(client->host);
        struct tegra_drm *tegra = drm->dev_private;
        struct iommu_group *group = NULL;
        int err;

        /*
         * If the host1x client is already attached to an IOMMU domain that is
         * not the shared IOMMU domain, don't try to attach it to a different
         * domain. This allows using the IOMMU-backed DMA API.
         */
        if (domain && domain != tegra->domain)
                return 0;

        if (tegra->domain) {
                group = iommu_group_get(client->dev);
                if (!group)
                        return -ENODEV;

                if (domain != tegra->domain) {
                        err = iommu_attach_group(tegra->domain, group);
                        if (err < 0) {
                                iommu_group_put(group);
                                return err;
                        }
                }

                tegra->use_explicit_iommu = true;
        }

        client->group = group;

        return 0;
}

void host1x_client_iommu_detach(struct host1x_client *client)
{
        struct drm_device *drm = dev_get_drvdata(client->host);
        struct tegra_drm *tegra = drm->dev_private;
        struct iommu_domain *domain;

        if (client->group) {
                /*
                 * Devices that are part of the same group may no longer be
                 * attached to a domain at this point because their group may
                 * have been detached by an earlier client.
                 */
                domain = iommu_get_domain_for_dev(client->dev);
                if (domain)
                        iommu_detach_group(tegra->domain, client->group);

                iommu_group_put(client->group);
                client->group = NULL;
        }
}

void *tegra_drm_alloc(struct tegra_drm *tegra, size_t size, dma_addr_t *dma)
{
        struct iova *alloc;
        void *virt;
        gfp_t gfp;
        int err;

        if (tegra->domain)
                size = iova_align(&tegra->carveout.domain, size);
        else
                size = PAGE_ALIGN(size);

        gfp = GFP_KERNEL | __GFP_ZERO;
        if (!tegra->domain) {
                /*
                 * Many units only support 32-bit addresses, even on 64-bit
                 * SoCs. If there is no IOMMU to translate into a 32-bit IO
                 * virtual address space, force allocations to be in the
                 * lower 32-bit range.
                 */
                gfp |= GFP_DMA;
        }

        virt = (void *)__get_free_pages(gfp, get_order(size));
        if (!virt)
                return ERR_PTR(-ENOMEM);

        if (!tegra->domain) {
                /*
                 * If IOMMU is disabled, devices address physical memory
                 * directly.
                 */
                *dma = virt_to_phys(virt);
                return virt;
        }

        alloc = alloc_iova(&tegra->carveout.domain,
                           size >> tegra->carveout.shift,

                           tegra->carveout.limit, true);
        if (!alloc) {
                err = -EBUSY;
                goto free_pages;
        }

        *dma = iova_dma_addr(&tegra->carveout.domain, alloc);
        err = iommu_map(tegra->domain, *dma, virt_to_phys(virt),
                        size, IOMMU_READ | IOMMU_WRITE);
        if (err < 0)
                goto free_iova;

        return virt;

free_iova:
        __free_iova(&tegra->carveout.domain, alloc);
free_pages:
        free_pages((unsigned long)virt, get_order(size));

        return ERR_PTR(err);
}

void tegra_drm_free(struct tegra_drm *tegra, size_t size, void *virt,
                    dma_addr_t dma)
{
        if (tegra->domain)
                size = iova_align(&tegra->carveout.domain, size);
        else
                size = PAGE_ALIGN(size);

        if (tegra->domain) {
                iommu_unmap(tegra->domain, dma, size);
                free_iova(&tegra->carveout.domain,
                          iova_pfn(&tegra->carveout.domain, dma));
        }

        free_pages((unsigned long)virt, get_order(size));
}

static bool host1x_drm_wants_iommu(struct host1x_device *dev)
{
        struct host1x *host1x = dev_get_drvdata(dev->dev.parent);
        struct iommu_domain *domain;

        /*
         * If the Tegra DRM clients are backed by an IOMMU, push buffers are
         * likely to be allocated beyond the 32-bit boundary if sufficient
         * system memory is available. This is problematic on earlier Tegra
         * generations where host1x supports a maximum of 32 address bits in
         * the GATHER opcode. In this case, unless host1x is behind an IOMMU
         * as well it won't be able to process buffers allocated beyond the
         * 32-bit boundary.
         *
         * The DMA API will use bounce buffers in this case, so that could
         * perhaps still be made to work, even if less efficient, but there
         * is another catch: in order to perform cache maintenance on pages
         * allocated for discontiguous buffers we need to map and unmap the
         * SG table representing these buffers. This is fine for something
         * small like a push buffer, but it exhausts the bounce buffer pool
         * (typically on the order of a few MiB) for framebuffers (many MiB
         * for any modern resolution).
         *
         * Work around this by making sure that Tegra DRM clients only use
         * an IOMMU if the parent host1x also uses an IOMMU.
         *
         * Note that there's still a small gap here that we don't cover: if
         * the DMA API is backed by an IOMMU there's no way to control which
         * device is attached to an IOMMU and which isn't, except via wiring
         * up the device tree appropriately. This is considered an problem
         * of integration, so care must be taken for the DT to be consistent.
         */
        domain = iommu_get_domain_for_dev(dev->dev.parent);

        /*
         * Tegra20 and Tegra30 don't support addressing memory beyond the
         * 32-bit boundary, so the regular GATHER opcodes will always be
         * sufficient and whether or not the host1x is attached to an IOMMU
         * doesn't matter.
         */
        if (!domain && host1x_get_dma_mask(host1x) <= DMA_BIT_MASK(32))
                return true;

        return domain != NULL;
}

static int host1x_drm_probe(struct host1x_device *dev)
{
        struct tegra_drm *tegra;
        struct drm_device *drm;
        int err;

        drm = drm_dev_alloc(&tegra_drm_driver, &dev->dev);
        if (IS_ERR(drm))
                return PTR_ERR(drm);

        tegra = kzalloc(sizeof(*tegra), GFP_KERNEL);
        if (!tegra) {
                err = -ENOMEM;
                goto put;
        }

        if (host1x_drm_wants_iommu(dev) && 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);

        dev_set_drvdata(&dev->dev, drm);
        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 = 0;
        drm->mode_config.max_height = 0;

        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(dev);
        if (err < 0)
                goto fbdev;

        /*
         * Now that all display controller have been initialized, the maximum
         * supported resolution is known and the bitmask for horizontal and
         * vertical bitfields can be computed.
         */
        tegra->hmask = drm->mode_config.max_width - 1;
        tegra->vmask = drm->mode_config.max_height - 1;

        if (tegra->use_explicit_iommu) {
                u64 carveout_start, carveout_end, gem_start, gem_end;
                u64 dma_mask = dma_get_mask(&dev->dev);
                dma_addr_t start, end;
                unsigned long order;

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

                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_DRIVER("IOMMU apertures:\n");
                DRM_DEBUG_DRIVER("  GEM: %#llx-%#llx\n", gem_start, gem_end);
                DRM_DEBUG_DRIVER("  Carveout: %#llx-%#llx\n", carveout_start,
                                 carveout_end);
        } else if (tegra->domain) {
                iommu_domain_free(tegra->domain);
                tegra->domain = NULL;
                iova_cache_put();
        }

        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 = drm_aperture_remove_framebuffers(false, "tegradrmfb");
        if (err < 0)
                goto hub;

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

        err = drm_dev_register(drm, 0);
        if (err < 0)
                goto fb;

        return 0;

fb:
        tegra_drm_fb_exit(drm);
hub:
        if (tegra->hub)
                tegra_display_hub_cleanup(tegra->hub);
device:
        if (tegra->domain) {
                mutex_destroy(&tegra->mm_lock);
                drm_mm_takedown(&tegra->mm);
                put_iova_domain(&tegra->carveout.domain);
                iova_cache_put();
        }

        host1x_device_exit(dev);
fbdev:
        drm_kms_helper_poll_fini(drm);
        tegra_drm_fb_free(drm);
config:
        drm_mode_config_cleanup(drm);
domain:
        if (tegra->domain)
                iommu_domain_free(tegra->domain);
free:
        kfree(tegra);
put:
        drm_dev_put(drm);
        return err;
}

static int host1x_drm_remove(struct host1x_device *dev)
{
        struct drm_device *drm = dev_get_drvdata(&dev->dev);
        struct tegra_drm *tegra = drm->dev_private;
        int err;

        drm_dev_unregister(drm);

        drm_kms_helper_poll_fini(drm);
        tegra_drm_fb_exit(drm);
        drm_atomic_helper_shutdown(drm);
        drm_mode_config_cleanup(drm);

        if (tegra->hub)
                tegra_display_hub_cleanup(tegra->hub);

        err = host1x_device_exit(dev);
        if (err < 0)
                dev_err(&dev->dev, "host1x device cleanup failed: %d\n", err);

        if (tegra->domain) {
                mutex_destroy(&tegra->mm_lock);
                drm_mm_takedown(&tegra->mm);
                put_iova_domain(&tegra->carveout.domain);
                iova_cache_put();
                iommu_domain_free(tegra->domain);
        }

        kfree(tegra);
        drm_dev_put(drm);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int host1x_drm_suspend(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        return drm_mode_config_helper_suspend(drm);
}

static int host1x_drm_resume(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        return drm_mode_config_helper_resume(drm);
}
#endif

static SIMPLE_DEV_PM_OPS(host1x_drm_pm_ops, host1x_drm_suspend,
                         host1x_drm_resume);

static const struct of_device_id host1x_drm_subdevs[] = {
        { .compatible = "nvidia,tegra20-dc", },
        { .compatible = "nvidia,tegra20-hdmi", },
        { .compatible = "nvidia,tegra20-gr2d", },
        { .compatible = "nvidia,tegra20-gr3d", },
        { .compatible = "nvidia,tegra30-dc", },
        { .compatible = "nvidia,tegra30-hdmi", },
        { .compatible = "nvidia,tegra30-gr2d", },
        { .compatible = "nvidia,tegra30-gr3d", },
        { .compatible = "nvidia,tegra114-dc", },
        { .compatible = "nvidia,tegra114-dsi", },
        { .compatible = "nvidia,tegra114-hdmi", },
        { .compatible = "nvidia,tegra114-gr2d", },
        { .compatible = "nvidia,tegra114-gr3d", },
        { .compatible = "nvidia,tegra124-dc", },
        { .compatible = "nvidia,tegra124-sor", },
        { .compatible = "nvidia,tegra124-hdmi", },
        { .compatible = "nvidia,tegra124-dsi", },
        { .compatible = "nvidia,tegra124-vic", },
        { .compatible = "nvidia,tegra132-dsi", },
        { .compatible = "nvidia,tegra210-dc", },
        { .compatible = "nvidia,tegra210-dsi", },
        { .compatible = "nvidia,tegra210-sor", },
        { .compatible = "nvidia,tegra210-sor1", },
        { .compatible = "nvidia,tegra210-vic", },
        { .compatible = "nvidia,tegra186-display", },
        { .compatible = "nvidia,tegra186-dc", },
        { .compatible = "nvidia,tegra186-sor", },
        { .compatible = "nvidia,tegra186-sor1", },
        { .compatible = "nvidia,tegra186-vic", },
        { .compatible = "nvidia,tegra194-display", },
        { .compatible = "nvidia,tegra194-dc", },
        { .compatible = "nvidia,tegra194-sor", },
        { .compatible = "nvidia,tegra194-vic", },
        { /* sentinel */ }
};

static struct host1x_driver host1x_drm_driver = {
        .driver = {
                .name = "drm",
                .pm = &host1x_drm_pm_ops,
        },
        .probe = host1x_drm_probe,
        .remove = host1x_drm_remove,
        .subdevs = host1x_drm_subdevs,
};

static struct platform_driver * const drivers[] = {
        &tegra_display_hub_driver,
        &tegra_dc_driver,
        &tegra_hdmi_driver,
        &tegra_dsi_driver,
        &tegra_dpaux_driver,
        &tegra_sor_driver,
        &tegra_gr2d_driver,
        &tegra_gr3d_driver,
        &tegra_vic_driver,
};

static int __init host1x_drm_init(void)
{
        int err;

        err = host1x_driver_register(&host1x_drm_driver);
        if (err < 0)
                return err;

        err = platform_register_drivers(drivers, ARRAY_SIZE(drivers));
        if (err < 0)
                goto unregister_host1x;

        return 0;

unregister_host1x:
        host1x_driver_unregister(&host1x_drm_driver);
        return err;
}
module_init(host1x_drm_init);

static void __exit host1x_drm_exit(void)
{
        platform_unregister_drivers(drivers, ARRAY_SIZE(drivers));
        host1x_driver_unregister(&host1x_drm_driver);
}
module_exit(host1x_drm_exit);

MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("NVIDIA Tegra DRM driver");
MODULE_LICENSE("GPL v2");