// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 */

#include <linux/dma-map-ops.h>
#include <linux/vmalloc.h>
#include <linux/spinlock.h>
#include <linux/shmem_fs.h>
#include <linux/dma-buf.h>

#include <drm/drm_dumb_buffers.h>
#include <drm/drm_prime.h>
#include <drm/drm_file.h>
#include <drm/drm_fourcc.h>

#include <trace/events/gpu_mem.h>

#include "msm_drv.h"
#include "msm_gem.h"
#include "msm_gpu.h"
#include "msm_kms.h"

static void update_device_mem(struct msm_drm_private *priv, ssize_t size)
{
        uint64_t total_mem = atomic64_add_return(size, &priv->total_mem);
        trace_gpu_mem_total(0, 0, total_mem);
}

static void update_ctx_mem(struct drm_file *file, ssize_t size)
{
        struct msm_context *ctx = file->driver_priv;
        uint64_t ctx_mem = atomic64_add_return(size, &ctx->ctx_mem);

        rcu_read_lock(); /* Locks file->pid! */
        trace_gpu_mem_total(0, pid_nr(rcu_dereference(file->pid)), ctx_mem);
        rcu_read_unlock();

}

static int msm_gem_open(struct drm_gem_object *obj, struct drm_file *file)
{
        msm_gem_vma_get(obj);
        update_ctx_mem(file, obj->size);
        return 0;
}

static void put_iova_spaces(struct drm_gem_object *obj, struct drm_gpuvm *vm,
                            bool close, const char *reason);

static void msm_gem_close(struct drm_gem_object *obj, struct drm_file *file)
{
        struct msm_context *ctx = file->driver_priv;
        struct drm_exec exec;

        update_ctx_mem(file, -obj->size);
        msm_gem_vma_put(obj);

        /*
         * If VM isn't created yet, nothing to cleanup.  And in fact calling
         * put_iova_spaces() with vm=NULL would be bad, in that it will tear-
         * down the mappings of shared buffers in other contexts.
         */
        if (!ctx->vm)
                return;

        /*
         * VM_BIND does not depend on implicit teardown of VMAs on handle
         * close, but instead on implicit teardown of the VM when the device
         * is closed (see msm_gem_vm_close())
         */
        if (msm_context_is_vmbind(ctx))
                return;

        /*
         * TODO we might need to kick this to a queue to avoid blocking
         * in CLOSE ioctl
         */
        dma_resv_wait_timeout(obj->resv, DMA_RESV_USAGE_BOOKKEEP, false,
                              MAX_SCHEDULE_TIMEOUT);

        msm_gem_lock_vm_and_obj(&exec, obj, ctx->vm);
        put_iova_spaces(obj, ctx->vm, true, "close");
        drm_exec_fini(&exec);     /* drop locks */
}

/*
 * Get/put for kms->vm VMA
 */

void msm_gem_vma_get(struct drm_gem_object *obj)
{
        atomic_inc(&to_msm_bo(obj)->vma_ref);
}

void msm_gem_vma_put(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;

        if (atomic_dec_return(&to_msm_bo(obj)->vma_ref))
                return;

        if (!priv->kms)
                return;

#ifdef CONFIG_DRM_MSM_KMS
        struct drm_exec exec;

        msm_gem_lock_vm_and_obj(&exec, obj, priv->kms->vm);
        put_iova_spaces(obj, priv->kms->vm, true, "vma_put");
        drm_exec_fini(&exec);     /* drop locks */
#endif
}

/*
 * Cache sync.. this is a bit over-complicated, to fit dma-mapping
 * API.  Really GPU cache is out of scope here (handled on cmdstream)
 * and all we need to do is invalidate newly allocated pages before
 * mapping to CPU as uncached/writecombine.
 *
 * On top of this, we have the added headache, that depending on
 * display generation, the display's iommu may be wired up to either
 * the toplevel drm device (mdss), or to the mdp sub-node, meaning
 * that here we either have dma-direct or iommu ops.
 *
 * Let this be a cautionary tail of abstraction gone wrong.
 */

static void sync_for_device(struct msm_gem_object *msm_obj)
{
        struct device *dev = msm_obj->base.dev->dev;

        dma_map_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
}

static void sync_for_cpu(struct msm_gem_object *msm_obj)
{
        struct device *dev = msm_obj->base.dev->dev;

        dma_unmap_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0);
}

static void update_lru_active(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        GEM_WARN_ON(!msm_obj->pages);

        if (msm_obj->pin_count) {
                drm_gem_lru_move_tail_locked(&priv->lru.pinned, obj);
        } else if (msm_obj->madv == MSM_MADV_WILLNEED) {
                drm_gem_lru_move_tail_locked(&priv->lru.willneed, obj);
        } else {
                GEM_WARN_ON(msm_obj->madv != MSM_MADV_DONTNEED);

                drm_gem_lru_move_tail_locked(&priv->lru.dontneed, obj);
        }
}

static void update_lru_locked(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(&msm_obj->base);

        if (!msm_obj->pages) {
                GEM_WARN_ON(msm_obj->pin_count);

                drm_gem_lru_move_tail_locked(&priv->lru.unbacked, obj);
        } else {
                update_lru_active(obj);
        }
}

static void update_lru(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;

        mutex_lock(&priv->lru.lock);
        update_lru_locked(obj);
        mutex_unlock(&priv->lru.lock);
}

static struct page **get_pages(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);

        if (!msm_obj->pages) {
                struct drm_device *dev = obj->dev;
                struct page **p;
                size_t npages = obj->size >> PAGE_SHIFT;

                p = drm_gem_get_pages(obj);

                if (IS_ERR(p)) {
                        DRM_DEV_ERROR(dev->dev, "could not get pages: %ld\n",
                                        PTR_ERR(p));
                        return p;
                }

                update_device_mem(dev->dev_private, obj->size);

                msm_obj->pages = p;

                msm_obj->sgt = drm_prime_pages_to_sg(obj->dev, p, npages);
                if (IS_ERR(msm_obj->sgt)) {
                        void *ptr = ERR_CAST(msm_obj->sgt);

                        DRM_DEV_ERROR(dev->dev, "failed to allocate sgt\n");
                        msm_obj->sgt = NULL;
                        return ptr;
                }

                /* For non-cached buffers, ensure the new pages are clean
                 * because display controller, GPU, etc. are not coherent:
                 */
                if (msm_obj->flags & MSM_BO_WC)
                        sync_for_device(msm_obj);

                update_lru(obj);
        }

        return msm_obj->pages;
}

static void put_pages(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        /*
         * Skip gpuvm in the object free path to avoid a WARN_ON() splat.
         * See explaination in msm_gem_assert_locked()
         */
        if (kref_read(&obj->refcount))
                drm_gpuvm_bo_gem_evict(obj, true);

        if (msm_obj->pages) {
                if (msm_obj->sgt) {
                        /* For non-cached buffers, ensure the new
                         * pages are clean because display controller,
                         * GPU, etc. are not coherent:
                         */
                        if (msm_obj->flags & MSM_BO_WC)
                                sync_for_cpu(msm_obj);

                        sg_free_table(msm_obj->sgt);
                        kfree(msm_obj->sgt);
                        msm_obj->sgt = NULL;
                }

                update_device_mem(obj->dev->dev_private, -obj->size);

                drm_gem_put_pages(obj, msm_obj->pages, true, false);

                msm_obj->pages = NULL;
                update_lru(obj);
        }
}

struct page **msm_gem_get_pages_locked(struct drm_gem_object *obj, unsigned madv)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);

        if (msm_obj->madv > madv) {
                DRM_DEV_DEBUG_DRIVER(obj->dev->dev, "Invalid madv state: %u vs %u\n",
                                     msm_obj->madv, madv);
                return ERR_PTR(-EBUSY);
        }

        return get_pages(obj);
}

/*
 * Update the pin count of the object, call under lru.lock
 */
void msm_gem_pin_obj_locked(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;

        msm_gem_assert_locked(obj);

        to_msm_bo(obj)->pin_count++;
        drm_gem_lru_move_tail_locked(&priv->lru.pinned, obj);
}

static void pin_obj_locked(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;

        mutex_lock(&priv->lru.lock);
        msm_gem_pin_obj_locked(obj);
        mutex_unlock(&priv->lru.lock);
}

struct page **msm_gem_pin_pages_locked(struct drm_gem_object *obj)
{
        struct page **p;

        msm_gem_assert_locked(obj);

        p = msm_gem_get_pages_locked(obj, MSM_MADV_WILLNEED);
        if (!IS_ERR(p))
                pin_obj_locked(obj);

        return p;
}

void msm_gem_unpin_pages_locked(struct drm_gem_object *obj)
{
        msm_gem_assert_locked(obj);

        msm_gem_unpin_locked(obj);
}

static pgprot_t msm_gem_pgprot(struct msm_gem_object *msm_obj, pgprot_t prot)
{
        if (msm_obj->flags & MSM_BO_WC)
                return pgprot_writecombine(prot);
        return prot;
}

static vm_fault_t msm_gem_fault(struct vm_fault *vmf)
{
        struct vm_area_struct *vma = vmf->vma;
        struct drm_gem_object *obj = vma->vm_private_data;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        struct page **pages;
        unsigned long pfn;
        pgoff_t pgoff;
        int err;
        vm_fault_t ret;

        /*
         * vm_ops.open/drm_gem_mmap_obj and close get and put
         * a reference on obj. So, we dont need to hold one here.
         */
        err = msm_gem_lock_interruptible(obj);
        if (err) {
                ret = VM_FAULT_NOPAGE;
                goto out;
        }

        if (GEM_WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED)) {
                msm_gem_unlock(obj);
                return VM_FAULT_SIGBUS;
        }

        /* make sure we have pages attached now */
        pages = get_pages(obj);
        if (IS_ERR(pages)) {
                ret = vmf_error(PTR_ERR(pages));
                goto out_unlock;
        }

        /* We don't use vmf->pgoff since that has the fake offset: */
        pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT;

        pfn = page_to_pfn(pages[pgoff]);

        VERB("Inserting %p pfn %lx, pa %lx", (void *)vmf->address,
                        pfn, pfn << PAGE_SHIFT);

        ret = vmf_insert_pfn(vma, vmf->address, pfn);

out_unlock:
        msm_gem_unlock(obj);
out:
        return ret;
}


static struct drm_gpuva *lookup_vma(struct drm_gem_object *obj,
                                    struct drm_gpuvm *vm)
{
        struct drm_gpuvm_bo *vm_bo;

        msm_gem_assert_locked(obj);

        drm_gem_for_each_gpuvm_bo (vm_bo, obj) {
                struct drm_gpuva *vma;

                drm_gpuvm_bo_for_each_va (vma, vm_bo) {
                        if (vma->vm == vm) {
                                /* lookup_vma() should only be used in paths
                                 * with at most one vma per vm
                                 */
                                GEM_WARN_ON(!list_is_singular(&vm_bo->list.gpuva));

                                return vma;
                        }
                }
        }

        return NULL;
}

/*
 * If close is true, this also closes the VMA (releasing the allocated
 * iova range) in addition to removing the iommu mapping.  In the eviction
 * case (!close), we keep the iova allocated, but only remove the iommu
 * mapping.
 */
static void
put_iova_spaces(struct drm_gem_object *obj, struct drm_gpuvm *vm,
                bool close, const char *reason)
{
        struct drm_gpuvm_bo *vm_bo, *tmp;

        msm_gem_assert_locked(obj);

        drm_gem_for_each_gpuvm_bo_safe (vm_bo, tmp, obj) {
                struct drm_gpuva *vma, *vmatmp;

                if (vm && vm_bo->vm != vm)
                        continue;

                drm_gpuvm_bo_get(vm_bo);

                drm_gpuvm_bo_for_each_va_safe (vma, vmatmp, vm_bo) {
                        msm_gem_vma_unmap(vma, reason);
                        if (close)
                                msm_gem_vma_close(vma);
                }

                drm_gpuvm_bo_put(vm_bo);
        }
}

static struct drm_gpuva *get_vma_locked(struct drm_gem_object *obj,
                                        struct drm_gpuvm *vm, u64 range_start,
                                        u64 range_end)
{
        struct drm_gpuva *vma;

        msm_gem_assert_locked(obj);

        vma = lookup_vma(obj, vm);

        if (!vma) {
                vma = msm_gem_vma_new(vm, obj, 0, range_start, range_end);
        } else {
                GEM_WARN_ON(vma->va.addr < range_start);
                GEM_WARN_ON((vma->va.addr + obj->size) > range_end);
        }

        return vma;
}

int msm_gem_prot(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        int prot = IOMMU_READ;

        if (!(msm_obj->flags & MSM_BO_GPU_READONLY))
                prot |= IOMMU_WRITE;

        if (msm_obj->flags & MSM_BO_MAP_PRIV)
                prot |= IOMMU_PRIV;

        if (msm_obj->flags & MSM_BO_CACHED_COHERENT)
                prot |= IOMMU_CACHE;

        return prot;
}

int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct drm_gpuva *vma)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        struct page **pages;
        int prot = msm_gem_prot(obj);

        msm_gem_assert_locked(obj);

        pages = msm_gem_get_pages_locked(obj, MSM_MADV_WILLNEED);
        if (IS_ERR(pages))
                return PTR_ERR(pages);

        return msm_gem_vma_map(vma, prot, msm_obj->sgt);
}

void msm_gem_unpin_locked(struct drm_gem_object *obj)
{
        struct msm_drm_private *priv = obj->dev->dev_private;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);

        mutex_lock(&priv->lru.lock);
        msm_obj->pin_count--;
        GEM_WARN_ON(msm_obj->pin_count < 0);
        update_lru_locked(obj);
        mutex_unlock(&priv->lru.lock);
}

/* Special unpin path for use in fence-signaling path, avoiding the need
 * to hold the obj lock by only depending on things that a protected by
 * the LRU lock.  In particular we know that that we already have backing
 * and and that the object's dma_resv has the fence for the current
 * submit/job which will prevent us racing against page eviction.
 */
void msm_gem_unpin_active(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_obj->pin_count--;
        GEM_WARN_ON(msm_obj->pin_count < 0);
        update_lru_active(obj);
}

struct drm_gpuva *msm_gem_get_vma_locked(struct drm_gem_object *obj,
                                         struct drm_gpuvm *vm)
{
        return get_vma_locked(obj, vm, 0, U64_MAX);
}

static int get_and_pin_iova_range_locked(struct drm_gem_object *obj,
                                         struct drm_gpuvm *vm, uint64_t *iova,
                                         u64 range_start, u64 range_end)
{
        struct drm_gpuva *vma;
        int ret;

        msm_gem_assert_locked(obj);

        if (to_msm_bo(obj)->flags & MSM_BO_NO_SHARE)
                return -EINVAL;

        vma = get_vma_locked(obj, vm, range_start, range_end);
        if (IS_ERR(vma))
                return PTR_ERR(vma);

        ret = msm_gem_pin_vma_locked(obj, vma);
        if (!ret) {
                *iova = vma->va.addr;
                pin_obj_locked(obj);
        }

        return ret;
}

/*
 * get iova and pin it. Should have a matching put
 * limits iova to specified range (in pages)
 */
int msm_gem_get_and_pin_iova_range(struct drm_gem_object *obj,
                                   struct drm_gpuvm *vm, uint64_t *iova,
                                   u64 range_start, u64 range_end)
{
        struct drm_exec exec;
        int ret;

        msm_gem_lock_vm_and_obj(&exec, obj, vm);
        ret = get_and_pin_iova_range_locked(obj, vm, iova, range_start, range_end);
        drm_exec_fini(&exec);     /* drop locks */

        return ret;
}

/* get iova and pin it. Should have a matching put */
int msm_gem_get_and_pin_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm,
                             uint64_t *iova)
{
        return msm_gem_get_and_pin_iova_range(obj, vm, iova, 0, U64_MAX);
}

/*
 * Get an iova but don't pin it. Doesn't need a put because iovas are currently
 * valid for the life of the object
 */
int msm_gem_get_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm,
                     uint64_t *iova)
{
        struct drm_gpuva *vma;
        struct drm_exec exec;
        int ret = 0;

        msm_gem_lock_vm_and_obj(&exec, obj, vm);
        vma = get_vma_locked(obj, vm, 0, U64_MAX);
        if (IS_ERR(vma)) {
                ret = PTR_ERR(vma);
        } else {
                *iova = vma->va.addr;
        }
        drm_exec_fini(&exec);     /* drop locks */

        return ret;
}

static int clear_iova(struct drm_gem_object *obj,
                      struct drm_gpuvm *vm)
{
        struct drm_gpuva *vma = lookup_vma(obj, vm);

        if (!vma)
                return 0;

        msm_gem_vma_unmap(vma, NULL);
        msm_gem_vma_close(vma);

        return 0;
}

/*
 * Get the requested iova but don't pin it.  Fails if the requested iova is
 * not available.  Doesn't need a put because iovas are currently valid for
 * the life of the object.
 *
 * Setting an iova of zero will clear the vma.
 */
int msm_gem_set_iova(struct drm_gem_object *obj,
                     struct drm_gpuvm *vm, uint64_t iova)
{
        struct drm_exec exec;
        int ret = 0;

        msm_gem_lock_vm_and_obj(&exec, obj, vm);
        if (!iova) {
                ret = clear_iova(obj, vm);
        } else {
                struct drm_gpuva *vma;
                vma = get_vma_locked(obj, vm, iova, iova + obj->size);
                if (IS_ERR(vma)) {
                        ret = PTR_ERR(vma);
                } else if (GEM_WARN_ON(vma->va.addr != iova)) {
                        clear_iova(obj, vm);
                        ret = -EBUSY;
                }
        }
        drm_exec_fini(&exec);     /* drop locks */

        return ret;
}

static bool is_kms_vm(struct drm_gpuvm *vm)
{
#ifdef CONFIG_DRM_MSM_KMS
        struct msm_drm_private *priv = vm->drm->dev_private;

        return priv->kms && (priv->kms->vm == vm);
#else
        return false;
#endif
}

/*
 * Unpin a iova by updating the reference counts. The memory isn't actually
 * purged until something else (shrinker, mm_notifier, destroy, etc) decides
 * to get rid of it
 */
void msm_gem_unpin_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm)
{
        struct drm_gpuva *vma;
        struct drm_exec exec;

        msm_gem_lock_vm_and_obj(&exec, obj, vm);
        vma = lookup_vma(obj, vm);
        if (vma) {
                msm_gem_unpin_locked(obj);
        }
        if (!is_kms_vm(vm))
                put_iova_spaces(obj, vm, true, "close");
        drm_exec_fini(&exec);     /* drop locks */
}

int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
                struct drm_mode_create_dumb *args)
{
        u32 fourcc;
        u64 pitch_align;
        int ret;

        /*
         * Adreno needs pitch aligned to 32 pixels. Compute the number
         * of bytes for a block of 32 pixels at the given color format.
         * Use the result as pitch alignment.
         */
        fourcc = drm_driver_color_mode_format(dev, args->bpp);
        if (fourcc != DRM_FORMAT_INVALID) {
                const struct drm_format_info *info;

                info = drm_format_info(fourcc);
                if (!info)
                        return -EINVAL;
                pitch_align = drm_format_info_min_pitch(info, 0, 32);
        } else {
                pitch_align = round_up(args->width, 32) * DIV_ROUND_UP(args->bpp, SZ_8);
        }
        if (!pitch_align || pitch_align > U32_MAX)
                return -EINVAL;
        ret = drm_mode_size_dumb(dev, args, pitch_align, 0);
        if (ret)
                return ret;

        return msm_gem_new_handle(dev, file, args->size,
                        MSM_BO_SCANOUT | MSM_BO_WC, &args->handle, "dumb");
}

static void *get_vaddr(struct drm_gem_object *obj, unsigned madv)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        struct page **pages;
        int ret = 0;

        msm_gem_assert_locked(obj);

        if (drm_gem_is_imported(obj))
                return ERR_PTR(-ENODEV);

        pages = msm_gem_get_pages_locked(obj, madv);
        if (IS_ERR(pages))
                return ERR_CAST(pages);

        pin_obj_locked(obj);

        /* increment vmap_count *before* vmap() call, so shrinker can
         * check vmap_count (is_vunmapable()) outside of msm_obj lock.
         * This guarantees that we won't try to msm_gem_vunmap() this
         * same object from within the vmap() call (while we already
         * hold msm_obj lock)
         */
        msm_obj->vmap_count++;

        if (!msm_obj->vaddr) {
                msm_obj->vaddr = vmap(pages, obj->size >> PAGE_SHIFT,
                                VM_MAP, msm_gem_pgprot(msm_obj, PAGE_KERNEL));
                if (msm_obj->vaddr == NULL) {
                        ret = -ENOMEM;
                        goto fail;
                }
        }

        return msm_obj->vaddr;

fail:
        msm_obj->vmap_count--;
        msm_gem_unpin_locked(obj);
        return ERR_PTR(ret);
}

void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj)
{
        return get_vaddr(obj, MSM_MADV_WILLNEED);
}

void *msm_gem_get_vaddr(struct drm_gem_object *obj)
{
        void *ret;

        msm_gem_lock(obj);
        ret = msm_gem_get_vaddr_locked(obj);
        msm_gem_unlock(obj);

        return ret;
}

/*
 * Don't use this!  It is for the very special case of dumping
 * submits from GPU hangs or faults, were the bo may already
 * be MSM_MADV_DONTNEED, but we know the buffer is still on the
 * active list.
 */
void *msm_gem_get_vaddr_active(struct drm_gem_object *obj)
{
        return get_vaddr(obj, __MSM_MADV_PURGED);
}

void msm_gem_put_vaddr_locked(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);
        GEM_WARN_ON(msm_obj->vmap_count < 1);

        msm_obj->vmap_count--;
        msm_gem_unpin_locked(obj);
}

void msm_gem_put_vaddr(struct drm_gem_object *obj)
{
        msm_gem_lock(obj);
        msm_gem_put_vaddr_locked(obj);
        msm_gem_unlock(obj);
}

/* Update madvise status, returns true if not purged, else
 * false or -errno.
 */
int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv)
{
        struct msm_drm_private *priv = obj->dev->dev_private;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_lock(obj);

        mutex_lock(&priv->lru.lock);

        if (msm_obj->madv != __MSM_MADV_PURGED)
                msm_obj->madv = madv;

        madv = msm_obj->madv;

        /* If the obj is inactive, we might need to move it
         * between inactive lists
         */
        update_lru_locked(obj);

        mutex_unlock(&priv->lru.lock);

        msm_gem_unlock(obj);

        return (madv != __MSM_MADV_PURGED);
}

void msm_gem_purge(struct drm_gem_object *obj)
{
        struct drm_device *dev = obj->dev;
        struct msm_drm_private *priv = obj->dev->dev_private;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);
        GEM_WARN_ON(!is_purgeable(msm_obj));

        /* Get rid of any iommu mapping(s): */
        put_iova_spaces(obj, NULL, false, "purge");

        msm_gem_vunmap(obj);

        drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);

        put_pages(obj);

        mutex_lock(&priv->lru.lock);
        /* A one-way transition: */
        msm_obj->madv = __MSM_MADV_PURGED;
        mutex_unlock(&priv->lru.lock);

        drm_gem_free_mmap_offset(obj);

        /* Our goal here is to return as much of the memory as
         * is possible back to the system as we are called from OOM.
         * To do this we must instruct the shmfs to drop all of its
         * backing pages, *now*.
         */
        shmem_truncate_range(file_inode(obj->filp), 0, (loff_t)-1);

        invalidate_mapping_pages(file_inode(obj->filp)->i_mapping,
                        0, (loff_t)-1);
}

/*
 * Unpin the backing pages and make them available to be swapped out.
 */
void msm_gem_evict(struct drm_gem_object *obj)
{
        struct drm_device *dev = obj->dev;
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);
        GEM_WARN_ON(is_unevictable(msm_obj));

        /* Get rid of any iommu mapping(s): */
        put_iova_spaces(obj, NULL, false, "evict");

        drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);

        put_pages(obj);
}

void msm_gem_vunmap(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        msm_gem_assert_locked(obj);

        if (!msm_obj->vaddr || GEM_WARN_ON(!is_vunmapable(msm_obj)))
                return;

        vunmap(msm_obj->vaddr);
        msm_obj->vaddr = NULL;
}

bool msm_gem_active(struct drm_gem_object *obj)
{
        msm_gem_assert_locked(obj);

        if (to_msm_bo(obj)->pin_count)
                return true;

        return !dma_resv_test_signaled(obj->resv, DMA_RESV_USAGE_BOOKKEEP);
}

int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout)
{
        bool write = !!(op & MSM_PREP_WRITE);
        unsigned long remain =
                op & MSM_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
        long ret;

        if (op & MSM_PREP_BOOST) {
                dma_resv_set_deadline(obj->resv, dma_resv_usage_rw(write),
                                      ktime_get());
        }

        ret = dma_resv_wait_timeout(obj->resv, dma_resv_usage_rw(write),
                                    true,  remain);
        if (ret == 0)
                return remain == 0 ? -EBUSY : -ETIMEDOUT;
        else if (ret < 0)
                return ret;

        /* TODO cache maintenance */

        return 0;
}

int msm_gem_cpu_fini(struct drm_gem_object *obj)
{
        /* TODO cache maintenance */
        return 0;
}

#ifdef CONFIG_DEBUG_FS
void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
                struct msm_gem_stats *stats)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        struct dma_resv *robj = obj->resv;
        uint64_t off = drm_vma_node_start(&obj->vma_node);
        const char *madv;

        if (!msm_gem_trylock(obj))
                return;

        stats->all.count++;
        stats->all.size += obj->size;

        if (msm_gem_active(obj)) {
                stats->active.count++;
                stats->active.size += obj->size;
        }

        if (msm_obj->pages) {
                stats->resident.count++;
                stats->resident.size += obj->size;
        }

        switch (msm_obj->madv) {
        case __MSM_MADV_PURGED:
                stats->purged.count++;
                stats->purged.size += obj->size;
                madv = " purged";
                break;
        case MSM_MADV_DONTNEED:
                stats->purgeable.count++;
                stats->purgeable.size += obj->size;
                madv = " purgeable";
                break;
        case MSM_MADV_WILLNEED:
        default:
                madv = "";
                break;
        }

        seq_printf(m, "%08x: %c %2d (%2d) %08llx %p",
                        msm_obj->flags, msm_gem_active(obj) ? 'A' : 'I',
                        obj->name, kref_read(&obj->refcount),
                        off, msm_obj->vaddr);

        seq_printf(m, " %08zu %9s %-32s\n", obj->size, madv, msm_obj->name);

        if (!list_empty(&obj->gpuva.list)) {
                struct drm_gpuvm_bo *vm_bo;

                seq_puts(m, "      vmas:");

                drm_gem_for_each_gpuvm_bo (vm_bo, obj) {
                        struct drm_gpuva *vma;

                        drm_gpuvm_bo_for_each_va (vma, vm_bo) {
                                const char *name, *comm;
                                struct msm_gem_vm *vm = to_msm_vm(vma->vm);
                                struct task_struct *task =
                                        get_pid_task(vm->pid, PIDTYPE_PID);
                                if (task) {
                                        comm = kstrdup(task->comm, GFP_KERNEL);
                                        put_task_struct(task);
                                } else {
                                        comm = NULL;
                                }
                                name = vm->base.name;

                                seq_printf(m, " [%s%s%s: vm=%p, %08llx, %smapped]",
                                           name, comm ? ":" : "", comm ? comm : "",
                                           vma->vm, vma->va.addr,
                                           to_msm_vma(vma)->mapped ? "" : "un");
                                kfree(comm);
                        }
                }

                seq_puts(m, "\n");
        }

        dma_resv_describe(robj, m);
        msm_gem_unlock(obj);
}

void msm_gem_describe_objects(struct list_head *list, struct seq_file *m)
{
        struct msm_gem_stats stats = {};
        struct msm_gem_object *msm_obj;

        seq_puts(m, "   flags       id ref  offset   kaddr            size     madv      name\n");
        list_for_each_entry(msm_obj, list, node) {
                struct drm_gem_object *obj = &msm_obj->base;
                seq_puts(m, "   ");
                msm_gem_describe(obj, m, &stats);
        }

        seq_printf(m, "Total:     %4d objects, %9zu bytes\n",
                        stats.all.count, stats.all.size);
        seq_printf(m, "Active:    %4d objects, %9zu bytes\n",
                        stats.active.count, stats.active.size);
        seq_printf(m, "Resident:  %4d objects, %9zu bytes\n",
                        stats.resident.count, stats.resident.size);
        seq_printf(m, "Purgeable: %4d objects, %9zu bytes\n",
                        stats.purgeable.count, stats.purgeable.size);
        seq_printf(m, "Purged:    %4d objects, %9zu bytes\n",
                        stats.purged.count, stats.purged.size);
}
#endif

/* don't call directly!  Use drm_gem_object_put() */
static void msm_gem_free_object(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        struct drm_device *dev = obj->dev;
        struct msm_drm_private *priv = dev->dev_private;
        struct drm_exec exec;

        mutex_lock(&priv->obj_lock);
        list_del(&msm_obj->node);
        mutex_unlock(&priv->obj_lock);

        /*
         * We need to lock any VMs the object is still attached to, but not
         * the object itself (see explaination in msm_gem_assert_locked()),
         * so just open-code this special case.
         *
         * Note that we skip the dance if we aren't attached to any VM.  This
         * is load bearing.  The driver needs to support two usage models:
         *
         * 1. Legacy kernel managed VM: Userspace expects the VMA's to be
         *    implicitly torn down when the object is freed, the VMA's do
         *    not hold a hard reference to the BO.
         *
         * 2. VM_BIND, userspace managed VM: The VMA holds a reference to the
         *    BO.  This can be dropped when the VM is closed and it's associated
         *    VMAs are torn down.  (See msm_gem_vm_close()).
         *
         * In the latter case the last reference to a BO can be dropped while
         * we already have the VM locked.  It would have already been removed
         * from the gpuva list, but lockdep doesn't know that.  Or understand
         * the differences between the two usage models.
         */
        if (!list_empty(&obj->gpuva.list)) {
                drm_exec_init(&exec, 0, 0);
                drm_exec_until_all_locked (&exec) {
                        struct drm_gpuvm_bo *vm_bo;
                        drm_gem_for_each_gpuvm_bo (vm_bo, obj) {
                                drm_exec_lock_obj(&exec,
                                                  drm_gpuvm_resv_obj(vm_bo->vm));
                                drm_exec_retry_on_contention(&exec);
                        }
                }
                put_iova_spaces(obj, NULL, true, "free");
                drm_exec_fini(&exec);     /* drop locks */
        }

        if (drm_gem_is_imported(obj)) {
                GEM_WARN_ON(msm_obj->vaddr);

                /* Don't drop the pages for imported dmabuf, as they are not
                 * ours, just free the array we allocated:
                 */
                kvfree(msm_obj->pages);

                drm_prime_gem_destroy(obj, msm_obj->sgt);
        } else {
                msm_gem_vunmap(obj);
                put_pages(obj);
        }

        /*
         * In error paths, we could end up here before msm_gem_new_handle()
         * has changed obj->resv to point to the shared resv.  In this case,
         * we don't want to drop a ref to the shared r_obj that we haven't
         * taken yet.
         */
        if ((msm_obj->flags & MSM_BO_NO_SHARE) && (obj->resv != &obj->_resv)) {
                struct drm_gem_object *r_obj =
                        container_of(obj->resv, struct drm_gem_object, _resv);

                /* Drop reference we hold to shared resv obj: */
                drm_gem_object_put(r_obj);
        }

        drm_gem_object_release(obj);

        kfree(msm_obj->metadata);
        kfree(msm_obj);
}

static int msm_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);

        vm_flags_set(vma, VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
        vma->vm_page_prot = msm_gem_pgprot(msm_obj, vm_get_page_prot(vma->vm_flags));

        return 0;
}

/* convenience method to construct a GEM buffer object, and userspace handle */
int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
                size_t size, uint32_t flags, uint32_t *handle,
                char *name)
{
        struct drm_gem_object *obj;
        int ret;

        obj = msm_gem_new(dev, size, flags);

        if (IS_ERR(obj))
                return PTR_ERR(obj);

        if (name)
                msm_gem_object_set_name(obj, "%s", name);

        if (flags & MSM_BO_NO_SHARE) {
                struct msm_context *ctx = file->driver_priv;
                struct drm_gem_object *r_obj = drm_gpuvm_resv_obj(ctx->vm);

                drm_gem_object_get(r_obj);

                obj->resv = r_obj->resv;
        }

        ret = drm_gem_handle_create(file, obj, handle);

        /* drop reference from allocate - handle holds it now */
        drm_gem_object_put(obj);

        return ret;
}

static enum drm_gem_object_status msm_gem_status(struct drm_gem_object *obj)
{
        struct msm_gem_object *msm_obj = to_msm_bo(obj);
        enum drm_gem_object_status status = 0;

        if (msm_obj->pages)
                status |= DRM_GEM_OBJECT_RESIDENT;

        if (msm_obj->madv == MSM_MADV_DONTNEED)
                status |= DRM_GEM_OBJECT_PURGEABLE;

        return status;
}

static const struct vm_operations_struct vm_ops = {
        .fault = msm_gem_fault,
        .open = drm_gem_vm_open,
        .close = drm_gem_vm_close,
};

static const struct drm_gem_object_funcs msm_gem_object_funcs = {
        .free = msm_gem_free_object,
        .open = msm_gem_open,
        .close = msm_gem_close,
        .export = msm_gem_prime_export,
        .pin = msm_gem_prime_pin,
        .unpin = msm_gem_prime_unpin,
        .get_sg_table = msm_gem_prime_get_sg_table,
        .vmap = msm_gem_prime_vmap,
        .vunmap = msm_gem_prime_vunmap,
        .mmap = msm_gem_object_mmap,
        .status = msm_gem_status,
        .vm_ops = &vm_ops,
};

static int msm_gem_new_impl(struct drm_device *dev, uint32_t flags,
                            struct drm_gem_object **obj)
{
        struct msm_drm_private *priv = dev->dev_private;
        struct msm_gem_object *msm_obj;

        switch (flags & MSM_BO_CACHE_MASK) {
        case MSM_BO_CACHED:
        case MSM_BO_WC:
                break;
        case MSM_BO_CACHED_COHERENT:
                if (priv->has_cached_coherent)
                        break;
                fallthrough;
        default:
                DRM_DEV_DEBUG(dev->dev, "invalid cache flag: %x\n",
                                (flags & MSM_BO_CACHE_MASK));
                return -EINVAL;
        }

        msm_obj = kzalloc_obj(*msm_obj);
        if (!msm_obj)
                return -ENOMEM;

        msm_obj->flags = flags;
        msm_obj->madv = MSM_MADV_WILLNEED;

        INIT_LIST_HEAD(&msm_obj->node);

        *obj = &msm_obj->base;
        (*obj)->funcs = &msm_gem_object_funcs;

        return 0;
}

struct drm_gem_object *msm_gem_new(struct drm_device *dev, size_t size, uint32_t flags)
{
        struct msm_drm_private *priv = dev->dev_private;
        struct msm_gem_object *msm_obj;
        struct drm_gem_object *obj = NULL;
        int ret;

        size = PAGE_ALIGN(size);

        /* Disallow zero sized objects as they make the underlying
         * infrastructure grumpy
         */
        if (size == 0)
                return ERR_PTR(-EINVAL);

        ret = msm_gem_new_impl(dev, flags, &obj);
        if (ret)
                return ERR_PTR(ret);

        msm_obj = to_msm_bo(obj);

        ret = drm_gem_object_init(dev, obj, size);
        if (ret)
                goto fail;
        /*
         * Our buffers are kept pinned, so allocating them from the
         * MOVABLE zone is a really bad idea, and conflicts with CMA.
         * See comments above new_inode() why this is required _and_
         * expected if you're going to pin these pages.
         */
        mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER);

        drm_gem_lru_move_tail(&priv->lru.unbacked, obj);

        mutex_lock(&priv->obj_lock);
        list_add_tail(&msm_obj->node, &priv->objects);
        mutex_unlock(&priv->obj_lock);

        ret = drm_gem_create_mmap_offset(obj);
        if (ret)
                goto fail;

        return obj;

fail:
        drm_gem_object_put(obj);
        return ERR_PTR(ret);
}

struct drm_gem_object *msm_gem_import(struct drm_device *dev,
                struct dma_buf *dmabuf, struct sg_table *sgt)
{
        struct msm_drm_private *priv = dev->dev_private;
        struct msm_gem_object *msm_obj;
        struct drm_gem_object *obj;
        size_t size, npages;
        int ret;

        size = PAGE_ALIGN(dmabuf->size);

        ret = msm_gem_new_impl(dev, MSM_BO_WC, &obj);
        if (ret)
                return ERR_PTR(ret);

        drm_gem_private_object_init(dev, obj, size);

        npages = size / PAGE_SIZE;

        msm_obj = to_msm_bo(obj);
        msm_gem_lock(obj);
        msm_obj->sgt = sgt;
        msm_obj->pages = kvmalloc_objs(struct page *, npages);
        if (!msm_obj->pages) {
                msm_gem_unlock(obj);
                ret = -ENOMEM;
                goto fail;
        }

        ret = drm_prime_sg_to_page_array(sgt, msm_obj->pages, npages);
        if (ret) {
                msm_gem_unlock(obj);
                goto fail;
        }

        msm_gem_unlock(obj);

        drm_gem_lru_move_tail(&priv->lru.pinned, obj);

        mutex_lock(&priv->obj_lock);
        list_add_tail(&msm_obj->node, &priv->objects);
        mutex_unlock(&priv->obj_lock);

        ret = drm_gem_create_mmap_offset(obj);
        if (ret)
                goto fail;

        return obj;

fail:
        drm_gem_object_put(obj);
        return ERR_PTR(ret);
}

void *msm_gem_kernel_new(struct drm_device *dev, size_t size, uint32_t flags,
                         struct drm_gpuvm *vm, struct drm_gem_object **bo,
                         uint64_t *iova)
{
        void *vaddr;
        struct drm_gem_object *obj = msm_gem_new(dev, size, flags);
        int ret;

        if (IS_ERR(obj))
                return ERR_CAST(obj);

        if (iova) {
                ret = msm_gem_get_and_pin_iova(obj, vm, iova);
                if (ret)
                        goto err;
        }

        vaddr = msm_gem_get_vaddr(obj);
        if (IS_ERR(vaddr)) {
                msm_gem_unpin_iova(obj, vm);
                ret = PTR_ERR(vaddr);
                goto err;
        }

        if (bo)
                *bo = obj;

        return vaddr;
err:
        drm_gem_object_put(obj);

        return ERR_PTR(ret);

}

void msm_gem_kernel_put(struct drm_gem_object *bo, struct drm_gpuvm *vm)
{
        if (IS_ERR_OR_NULL(bo))
                return;

        msm_gem_put_vaddr(bo);
        msm_gem_unpin_iova(bo, vm);
        drm_gem_object_put(bo);
}

void msm_gem_object_set_name(struct drm_gem_object *bo, const char *fmt, ...)
{
        struct msm_gem_object *msm_obj = to_msm_bo(bo);
        va_list ap;

        if (!fmt)
                return;

        va_start(ap, fmt);
        vsnprintf(msm_obj->name, sizeof(msm_obj->name), fmt, ap);
        va_end(ap);
}