// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2015 Etnaviv Project
 */

#include <drm/drm_file.h>
#include <drm/drm_print.h>
#include <linux/dma-fence-array.h>
#include <linux/file.h>
#include <linux/dma-resv.h>
#include <linux/sync_file.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>

#include "etnaviv_cmdbuf.h"
#include "etnaviv_drv.h"
#include "etnaviv_gpu.h"
#include "etnaviv_gem.h"
#include "etnaviv_perfmon.h"
#include "etnaviv_sched.h"

/*
 * Cmdstream submission:
 */

#define BO_INVALID_FLAGS ~(ETNA_SUBMIT_BO_READ | ETNA_SUBMIT_BO_WRITE)
/* make sure these don't conflict w/ ETNAVIV_SUBMIT_BO_x */
#define BO_LOCKED   0x4000
#define BO_PINNED   0x2000

static struct etnaviv_gem_submit *submit_create(struct drm_device *dev,
                struct etnaviv_gpu *gpu, size_t nr_bos, size_t nr_pmrs)
{
        struct etnaviv_gem_submit *submit;
        size_t sz = size_vstruct(nr_bos, sizeof(submit->bos[0]), sizeof(*submit));

        submit = kzalloc(sz, GFP_KERNEL);
        if (!submit)
                return NULL;

        submit->pmrs = kzalloc_objs(struct etnaviv_perfmon_request, nr_pmrs);
        if (!submit->pmrs) {
                kfree(submit);
                return NULL;
        }
        submit->nr_pmrs = nr_pmrs;

        submit->gpu = gpu;
        kref_init(&submit->refcount);

        return submit;
}

static int submit_lookup_objects(struct etnaviv_gem_submit *submit,
        struct drm_file *file, struct drm_etnaviv_gem_submit_bo *submit_bos,
        unsigned nr_bos)
{
        struct drm_etnaviv_gem_submit_bo *bo;
        unsigned i;
        int ret = 0;

        spin_lock(&file->table_lock);

        for (i = 0, bo = submit_bos; i < nr_bos; i++, bo++) {
                struct drm_gem_object *obj;

                if (bo->flags & BO_INVALID_FLAGS) {
                        DRM_ERROR("invalid flags: %x\n", bo->flags);
                        ret = -EINVAL;
                        goto out_unlock;
                }

                submit->bos[i].flags = bo->flags;
                if (submit->flags & ETNA_SUBMIT_SOFTPIN) {
                        if (bo->presumed < ETNAVIV_SOFTPIN_START_ADDRESS) {
                                DRM_ERROR("invalid softpin address\n");
                                ret = -EINVAL;
                                goto out_unlock;
                        }
                        submit->bos[i].va = bo->presumed;
                }

                /* normally use drm_gem_object_lookup(), but for bulk lookup
                 * all under single table_lock just hit object_idr directly:
                 */
                obj = idr_find(&file->object_idr, bo->handle);
                if (!obj) {
                        DRM_ERROR("invalid handle %u at index %u\n",
                                  bo->handle, i);
                        ret = -EINVAL;
                        goto out_unlock;
                }

                /*
                 * Take a refcount on the object. The file table lock
                 * prevents the object_idr's refcount on this being dropped.
                 */
                drm_gem_object_get(obj);

                submit->bos[i].obj = to_etnaviv_bo(obj);
        }

out_unlock:
        submit->nr_bos = i;
        spin_unlock(&file->table_lock);

        return ret;
}

static void submit_unlock_object(struct etnaviv_gem_submit *submit, int i)
{
        if (submit->bos[i].flags & BO_LOCKED) {
                struct drm_gem_object *obj = &submit->bos[i].obj->base;

                dma_resv_unlock(obj->resv);
                submit->bos[i].flags &= ~BO_LOCKED;
        }
}

static int submit_lock_objects(struct etnaviv_gem_submit *submit,
                struct ww_acquire_ctx *ticket)
{
        int contended, slow_locked = -1, i, ret = 0;

retry:
        for (i = 0; i < submit->nr_bos; i++) {
                struct drm_gem_object *obj = &submit->bos[i].obj->base;

                if (slow_locked == i)
                        slow_locked = -1;

                contended = i;

                if (!(submit->bos[i].flags & BO_LOCKED)) {
                        ret = dma_resv_lock_interruptible(obj->resv, ticket);
                        if (ret == -EALREADY)
                                DRM_ERROR("BO at index %u already on submit list\n",
                                          i);
                        if (ret)
                                goto fail;
                        submit->bos[i].flags |= BO_LOCKED;
                }
        }

        ww_acquire_done(ticket);

        return 0;

fail:
        for (; i >= 0; i--)
                submit_unlock_object(submit, i);

        if (slow_locked > 0)
                submit_unlock_object(submit, slow_locked);

        if (ret == -EDEADLK) {
                struct drm_gem_object *obj;

                obj = &submit->bos[contended].obj->base;

                /* we lost out in a seqno race, lock and retry.. */
                ret = dma_resv_lock_slow_interruptible(obj->resv, ticket);
                if (!ret) {
                        submit->bos[contended].flags |= BO_LOCKED;
                        slow_locked = contended;
                        goto retry;
                }
        }

        return ret;
}

static int submit_fence_sync(struct etnaviv_gem_submit *submit)
{
        int i, ret = 0;

        for (i = 0; i < submit->nr_bos; i++) {
                struct etnaviv_gem_submit_bo *bo = &submit->bos[i];
                struct dma_resv *robj = bo->obj->base.resv;

                ret = dma_resv_reserve_fences(robj, 1);
                if (ret)
                        return ret;

                if (submit->flags & ETNA_SUBMIT_NO_IMPLICIT)
                        continue;

                ret = drm_sched_job_add_implicit_dependencies(&submit->sched_job,
                                                              &bo->obj->base,
                                                              bo->flags & ETNA_SUBMIT_BO_WRITE);
                if (ret)
                        return ret;
        }

        return ret;
}

static void submit_attach_object_fences(struct etnaviv_gem_submit *submit)
{
        int i;

        for (i = 0; i < submit->nr_bos; i++) {
                struct drm_gem_object *obj = &submit->bos[i].obj->base;
                bool write = submit->bos[i].flags & ETNA_SUBMIT_BO_WRITE;

                dma_resv_add_fence(obj->resv, submit->out_fence, write ?
                                   DMA_RESV_USAGE_WRITE : DMA_RESV_USAGE_READ);
                submit_unlock_object(submit, i);
        }
}

static int submit_pin_objects(struct etnaviv_gem_submit *submit)
{
        int i, ret = 0;

        for (i = 0; i < submit->nr_bos; i++) {
                struct etnaviv_gem_object *etnaviv_obj = submit->bos[i].obj;
                struct etnaviv_vram_mapping *mapping;

                mapping = etnaviv_gem_mapping_get(&etnaviv_obj->base,
                                                  submit->mmu_context,
                                                  submit->bos[i].va);
                if (IS_ERR(mapping)) {
                        ret = PTR_ERR(mapping);
                        break;
                }

                if ((submit->flags & ETNA_SUBMIT_SOFTPIN) &&
                     submit->bos[i].va != mapping->iova) {
                        etnaviv_gem_mapping_unreference(mapping);
                        return -EINVAL;
                }

                atomic_inc(&etnaviv_obj->gpu_active);

                submit->bos[i].flags |= BO_PINNED;
                submit->bos[i].mapping = mapping;
        }

        return ret;
}

static int submit_bo(struct etnaviv_gem_submit *submit, u32 idx,
        struct etnaviv_gem_submit_bo **bo)
{
        if (idx >= submit->nr_bos) {
                DRM_ERROR("invalid buffer index: %u (out of %u)\n",
                                idx, submit->nr_bos);
                return -EINVAL;
        }

        *bo = &submit->bos[idx];

        return 0;
}

/* process the reloc's and patch up the cmdstream as needed: */
static int submit_reloc(struct etnaviv_gem_submit *submit, void *stream,
                u32 size, const struct drm_etnaviv_gem_submit_reloc *relocs,
                u32 nr_relocs)
{
        u32 i, last_offset = 0;
        u32 *ptr = stream;
        int ret;

        /* Submits using softpin don't blend with relocs */
        if ((submit->flags & ETNA_SUBMIT_SOFTPIN) && nr_relocs != 0)
                return -EINVAL;

        for (i = 0; i < nr_relocs; i++) {
                const struct drm_etnaviv_gem_submit_reloc *r = relocs + i;
                struct etnaviv_gem_submit_bo *bo;
                u32 off;

                if (unlikely(r->flags)) {
                        DRM_ERROR("invalid reloc flags\n");
                        return -EINVAL;
                }

                if (r->submit_offset % 4) {
                        DRM_ERROR("non-aligned reloc offset: %u\n",
                                  r->submit_offset);
                        return -EINVAL;
                }

                /* offset in dwords: */
                off = r->submit_offset / 4;

                if ((off >= size ) ||
                                (off < last_offset)) {
                        DRM_ERROR("invalid offset %u at reloc %u\n", off, i);
                        return -EINVAL;
                }

                ret = submit_bo(submit, r->reloc_idx, &bo);
                if (ret)
                        return ret;

                if (r->reloc_offset > bo->obj->base.size - sizeof(*ptr)) {
                        DRM_ERROR("relocation %u outside object\n", i);
                        return -EINVAL;
                }

                ptr[off] = bo->mapping->iova + r->reloc_offset;

                last_offset = off;
        }

        return 0;
}

static int submit_perfmon_validate(struct etnaviv_gem_submit *submit,
                u32 exec_state, const struct drm_etnaviv_gem_submit_pmr *pmrs)
{
        u32 i;

        for (i = 0; i < submit->nr_pmrs; i++) {
                const struct drm_etnaviv_gem_submit_pmr *r = pmrs + i;
                struct etnaviv_gem_submit_bo *bo;
                int ret;

                ret = submit_bo(submit, r->read_idx, &bo);
                if (ret)
                        return ret;

                /* at offset 0 a sequence number gets stored used for userspace sync */
                if (r->read_offset == 0) {
                        DRM_ERROR("perfmon request: offset is 0");
                        return -EINVAL;
                }

                if (r->read_offset >= bo->obj->base.size - sizeof(u32)) {
                        DRM_ERROR("perfmon request: offset %u outside object", i);
                        return -EINVAL;
                }

                if (r->flags & ~(ETNA_PM_PROCESS_PRE | ETNA_PM_PROCESS_POST)) {
                        DRM_ERROR("perfmon request: flags are not valid");
                        return -EINVAL;
                }

                if (etnaviv_pm_req_validate(r, exec_state)) {
                        DRM_ERROR("perfmon request: domain or signal not valid");
                        return -EINVAL;
                }

                submit->pmrs[i].flags = r->flags;
                submit->pmrs[i].domain = r->domain;
                submit->pmrs[i].signal = r->signal;
                submit->pmrs[i].sequence = r->sequence;
                submit->pmrs[i].offset = r->read_offset;
                submit->pmrs[i].bo_vma = etnaviv_gem_vmap(&bo->obj->base);
        }

        return 0;
}

static void submit_cleanup(struct kref *kref)
{
        struct etnaviv_gem_submit *submit =
                        container_of(kref, struct etnaviv_gem_submit, refcount);
        unsigned i;

        if (submit->cmdbuf.suballoc)
                etnaviv_cmdbuf_free(&submit->cmdbuf);

        if (submit->mmu_context)
                etnaviv_iommu_context_put(submit->mmu_context);

        if (submit->prev_mmu_context)
                etnaviv_iommu_context_put(submit->prev_mmu_context);

        for (i = 0; i < submit->nr_bos; i++) {
                struct etnaviv_gem_object *etnaviv_obj = submit->bos[i].obj;

                /* unpin all objects */
                if (submit->bos[i].flags & BO_PINNED) {
                        etnaviv_gem_mapping_unreference(submit->bos[i].mapping);
                        atomic_dec(&etnaviv_obj->gpu_active);
                        submit->bos[i].mapping = NULL;
                        submit->bos[i].flags &= ~BO_PINNED;
                }

                /* if the GPU submit failed, objects might still be locked */
                submit_unlock_object(submit, i);
                drm_gem_object_put(&etnaviv_obj->base);
        }

        wake_up_all(&submit->gpu->fence_event);

        if (submit->out_fence) {
                /*
                 * Remove from user fence array before dropping the reference,
                 * so fence can not be found in lookup anymore.
                 */
                xa_erase(&submit->gpu->user_fences, submit->out_fence_id);
                dma_fence_put(submit->out_fence);
        }

        put_pid(submit->pid);

        kfree(submit->pmrs);
        kfree(submit);
}

void etnaviv_submit_put(struct etnaviv_gem_submit *submit)
{
        kref_put(&submit->refcount, submit_cleanup);
}

int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
                struct drm_file *file)
{
        struct etnaviv_file_private *ctx = file->driver_priv;
        struct etnaviv_drm_private *priv = dev->dev_private;
        struct drm_etnaviv_gem_submit *args = data;
        struct drm_etnaviv_gem_submit_reloc *relocs;
        struct drm_etnaviv_gem_submit_pmr *pmrs;
        struct drm_etnaviv_gem_submit_bo *bos;
        struct etnaviv_gem_submit *submit;
        struct etnaviv_gpu *gpu;
        struct sync_file *sync_file = NULL;
        struct ww_acquire_ctx ticket;
        int out_fence_fd = -1;
        struct pid *pid = get_pid(task_pid(current));
        void *stream;
        int ret;

        if (args->pipe >= ETNA_MAX_PIPES)
                return -EINVAL;

        gpu = priv->gpu[args->pipe];
        if (!gpu)
                return -ENXIO;

        if (args->stream_size % 4) {
                DRM_ERROR("non-aligned cmdstream buffer size: %u\n",
                          args->stream_size);
                return -EINVAL;
        }

        if (args->exec_state != ETNA_PIPE_3D &&
            args->exec_state != ETNA_PIPE_2D &&
            args->exec_state != ETNA_PIPE_VG) {
                DRM_ERROR("invalid exec_state: 0x%x\n", args->exec_state);
                return -EINVAL;
        }

        if (args->flags & ~ETNA_SUBMIT_FLAGS) {
                DRM_ERROR("invalid flags: 0x%x\n", args->flags);
                return -EINVAL;
        }

        if ((args->flags & ETNA_SUBMIT_SOFTPIN) &&
            priv->mmu_global->version != ETNAVIV_IOMMU_V2) {
                DRM_ERROR("softpin requested on incompatible MMU\n");
                return -EINVAL;
        }

        if (args->stream_size > SZ_128K || args->nr_relocs > SZ_128K ||
            args->nr_bos > SZ_128K || args->nr_pmrs > 128) {
                DRM_ERROR("submit arguments out of size limits\n");
                return -EINVAL;
        }

        /*
         * Copy the command submission and bo array to kernel space in
         * one go, and do this outside of any locks.
         */
        bos = kvmalloc_objs(*bos, args->nr_bos);
        relocs = kvmalloc_objs(*relocs, args->nr_relocs);
        pmrs = kvmalloc_objs(*pmrs, args->nr_pmrs);
        stream = kvmalloc_array(1, args->stream_size, GFP_KERNEL);
        if (!bos || !relocs || !pmrs || !stream) {
                ret = -ENOMEM;
                goto err_submit_cmds;
        }

        ret = copy_from_user(bos, u64_to_user_ptr(args->bos),
                             args->nr_bos * sizeof(*bos));
        if (ret) {
                ret = -EFAULT;
                goto err_submit_cmds;
        }

        ret = copy_from_user(relocs, u64_to_user_ptr(args->relocs),
                             args->nr_relocs * sizeof(*relocs));
        if (ret) {
                ret = -EFAULT;
                goto err_submit_cmds;
        }

        ret = copy_from_user(pmrs, u64_to_user_ptr(args->pmrs),
                             args->nr_pmrs * sizeof(*pmrs));
        if (ret) {
                ret = -EFAULT;
                goto err_submit_cmds;
        }

        ret = copy_from_user(stream, u64_to_user_ptr(args->stream),
                             args->stream_size);
        if (ret) {
                ret = -EFAULT;
                goto err_submit_cmds;
        }

        if (args->flags & ETNA_SUBMIT_FENCE_FD_OUT) {
                out_fence_fd = get_unused_fd_flags(O_CLOEXEC);
                if (out_fence_fd < 0) {
                        ret = out_fence_fd;
                        goto err_submit_cmds;
                }
        }

        ww_acquire_init(&ticket, &reservation_ww_class);

        submit = submit_create(dev, gpu, args->nr_bos, args->nr_pmrs);
        if (!submit) {
                ret = -ENOMEM;
                goto err_submit_ww_acquire;
        }

        submit->pid = pid;

        ret = etnaviv_cmdbuf_init(priv->cmdbuf_suballoc, &submit->cmdbuf,
                                  ALIGN(args->stream_size, 8) + 8);
        if (ret)
                goto err_submit_put;

        submit->ctx = file->driver_priv;
        submit->mmu_context = etnaviv_iommu_context_get(submit->ctx->mmu);
        submit->exec_state = args->exec_state;
        submit->flags = args->flags;

        ret = drm_sched_job_init(&submit->sched_job,
                                 &ctx->sched_entity[args->pipe],
                                 1, submit->ctx, file->client_id);
        if (ret)
                goto err_submit_put;

        ret = submit_lookup_objects(submit, file, bos, args->nr_bos);
        if (ret)
                goto err_submit_job;

        if ((priv->mmu_global->version != ETNAVIV_IOMMU_V2) &&
            !etnaviv_cmd_validate_one(gpu, stream, args->stream_size / 4,
                                      relocs, args->nr_relocs)) {
                ret = -EINVAL;
                goto err_submit_job;
        }

        if (args->flags & ETNA_SUBMIT_FENCE_FD_IN) {
                struct dma_fence *in_fence = sync_file_get_fence(args->fence_fd);
                if (!in_fence) {
                        ret = -EINVAL;
                        goto err_submit_job;
                }

                ret = drm_sched_job_add_dependency(&submit->sched_job,
                                                   in_fence);
                if (ret)
                        goto err_submit_job;
        }

        ret = submit_pin_objects(submit);
        if (ret)
                goto err_submit_job;

        ret = submit_reloc(submit, stream, args->stream_size / 4,
                           relocs, args->nr_relocs);
        if (ret)
                goto err_submit_job;

        ret = submit_perfmon_validate(submit, args->exec_state, pmrs);
        if (ret)
                goto err_submit_job;

        memcpy(submit->cmdbuf.vaddr, stream, args->stream_size);

        ret = submit_lock_objects(submit, &ticket);
        if (ret)
                goto err_submit_job;

        ret = submit_fence_sync(submit);
        if (ret)
                goto err_submit_job;

        ret = etnaviv_sched_push_job(submit);
        if (ret)
                goto err_submit_job;

        submit_attach_object_fences(submit);

        if (args->flags & ETNA_SUBMIT_FENCE_FD_OUT) {
                /*
                 * This can be improved: ideally we want to allocate the sync
                 * file before kicking off the GPU job and just attach the
                 * fence to the sync file here, eliminating the ENOMEM
                 * possibility at this stage.
                 */
                sync_file = sync_file_create(submit->out_fence);
                if (!sync_file) {
                        ret = -ENOMEM;
                        /*
                         * When this late error is hit, the submit has already
                         * been handed over to the scheduler. At this point
                         * the sched_job must not be cleaned up.
                         */
                        goto err_submit_put;
                }
                fd_install(out_fence_fd, sync_file->file);
        }

        args->fence_fd = out_fence_fd;
        args->fence = submit->out_fence_id;

err_submit_job:
        if (ret)
                drm_sched_job_cleanup(&submit->sched_job);
err_submit_put:
        etnaviv_submit_put(submit);

err_submit_ww_acquire:
        ww_acquire_fini(&ticket);

err_submit_cmds:
        if (ret && (out_fence_fd >= 0))
                put_unused_fd(out_fence_fd);
        kvfree(stream);
        kvfree(bos);
        kvfree(relocs);
        kvfree(pmrs);

        return ret;
}