/*
 * Copyright 2014 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <linux/mutex.h>
#include <linux/log2.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/slab.h>
#include <linux/amd-iommu.h>
#include <linux/notifier.h>
#include <linux/compat.h>
#include <linux/mman.h>
#include <linux/file.h>
#include "amdgpu_amdkfd.h"

struct mm_struct;

#include "kfd_priv.h"
#include "kfd_device_queue_manager.h"
#include "kfd_dbgmgr.h"
#include "kfd_iommu.h"

/*
 * List of struct kfd_process (field kfd_process).
 * Unique/indexed by mm_struct*
 */
DEFINE_HASHTABLE(kfd_processes_table, KFD_PROCESS_TABLE_SIZE);
static DEFINE_MUTEX(kfd_processes_mutex);

DEFINE_SRCU(kfd_processes_srcu);

/* For process termination handling */
static struct workqueue_struct *kfd_process_wq;

/* Ordered, single-threaded workqueue for restoring evicted
 * processes. Restoring multiple processes concurrently under memory
 * pressure can lead to processes blocking each other from validating
 * their BOs and result in a live-lock situation where processes
 * remain evicted indefinitely.
 */
static struct workqueue_struct *kfd_restore_wq;

static struct kfd_process *find_process(const struct task_struct *thread);
static void kfd_process_ref_release(struct kref *ref);
static struct kfd_process *create_process(const struct task_struct *thread,
                                        struct file *filep);

static void evict_process_worker(struct work_struct *work);
static void restore_process_worker(struct work_struct *work);

struct kfd_procfs_tree {
        struct kobject *kobj;
};

static struct kfd_procfs_tree procfs;

static ssize_t kfd_procfs_show(struct kobject *kobj, struct attribute *attr,
                               char *buffer)
{
        int val = 0;

        if (strcmp(attr->name, "pasid") == 0) {
                struct kfd_process *p = container_of(attr, struct kfd_process,
                                                     attr_pasid);
                val = p->pasid;
        } else {
                pr_err("Invalid attribute");
                return -EINVAL;
        }

        return snprintf(buffer, PAGE_SIZE, "%d\n", val);
}

static void kfd_procfs_kobj_release(struct kobject *kobj)
{
        kfree(kobj);
}

static const struct sysfs_ops kfd_procfs_ops = {
        .show = kfd_procfs_show,
};

static struct kobj_type procfs_type = {
        .release = kfd_procfs_kobj_release,
        .sysfs_ops = &kfd_procfs_ops,
};

void kfd_procfs_init(void)
{
        int ret = 0;

        procfs.kobj = kfd_alloc_struct(procfs.kobj);
        if (!procfs.kobj)
                return;

        ret = kobject_init_and_add(procfs.kobj, &procfs_type,
                                   &kfd_device->kobj, "proc");
        if (ret) {
                pr_warn("Could not create procfs proc folder");
                /* If we fail to create the procfs, clean up */
                kfd_procfs_shutdown();
        }
}

void kfd_procfs_shutdown(void)
{
        if (procfs.kobj) {
                kobject_del(procfs.kobj);
                kobject_put(procfs.kobj);
                procfs.kobj = NULL;
        }
}

int kfd_process_create_wq(void)
{
        if (!kfd_process_wq)
                kfd_process_wq = alloc_workqueue("kfd_process_wq", 0, 0);
        if (!kfd_restore_wq)
                kfd_restore_wq = alloc_ordered_workqueue("kfd_restore_wq", 0);

        if (!kfd_process_wq || !kfd_restore_wq) {
                kfd_process_destroy_wq();
                return -ENOMEM;
        }

        return 0;
}

void kfd_process_destroy_wq(void)
{
        if (kfd_process_wq) {
                destroy_workqueue(kfd_process_wq);
                kfd_process_wq = NULL;
        }
        if (kfd_restore_wq) {
                destroy_workqueue(kfd_restore_wq);
                kfd_restore_wq = NULL;
        }
}

static void kfd_process_free_gpuvm(struct kgd_mem *mem,
                        struct kfd_process_device *pdd)
{
        struct kfd_dev *dev = pdd->dev;

        amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(dev->kgd, mem, pdd->vm);
        amdgpu_amdkfd_gpuvm_free_memory_of_gpu(dev->kgd, mem);
}

/* kfd_process_alloc_gpuvm - Allocate GPU VM for the KFD process
 *      This function should be only called right after the process
 *      is created and when kfd_processes_mutex is still being held
 *      to avoid concurrency. Because of that exclusiveness, we do
 *      not need to take p->mutex.
 */
static int kfd_process_alloc_gpuvm(struct kfd_process_device *pdd,
                                   uint64_t gpu_va, uint32_t size,
                                   uint32_t flags, void **kptr)
{
        struct kfd_dev *kdev = pdd->dev;
        struct kgd_mem *mem = NULL;
        int handle;
        int err;

        err = amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(kdev->kgd, gpu_va, size,
                                                 pdd->vm, &mem, NULL, flags);
        if (err)
                goto err_alloc_mem;

        err = amdgpu_amdkfd_gpuvm_map_memory_to_gpu(kdev->kgd, mem, pdd->vm);
        if (err)
                goto err_map_mem;

        err = amdgpu_amdkfd_gpuvm_sync_memory(kdev->kgd, mem, true);
        if (err) {
                pr_debug("Sync memory failed, wait interrupted by user signal\n");
                goto sync_memory_failed;
        }

        /* Create an obj handle so kfd_process_device_remove_obj_handle
         * will take care of the bo removal when the process finishes.
         * We do not need to take p->mutex, because the process is just
         * created and the ioctls have not had the chance to run.
         */
        handle = kfd_process_device_create_obj_handle(pdd, mem);

        if (handle < 0) {
                err = handle;
                goto free_gpuvm;
        }

        if (kptr) {
                err = amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel(kdev->kgd,
                                (struct kgd_mem *)mem, kptr, NULL);
                if (err) {
                        pr_debug("Map GTT BO to kernel failed\n");
                        goto free_obj_handle;
                }
        }

        return err;

free_obj_handle:
        kfd_process_device_remove_obj_handle(pdd, handle);
free_gpuvm:
sync_memory_failed:
        kfd_process_free_gpuvm(mem, pdd);
        return err;

err_map_mem:
        amdgpu_amdkfd_gpuvm_free_memory_of_gpu(kdev->kgd, mem);
err_alloc_mem:
        *kptr = NULL;
        return err;
}

/* kfd_process_device_reserve_ib_mem - Reserve memory inside the
 *      process for IB usage The memory reserved is for KFD to submit
 *      IB to AMDGPU from kernel.  If the memory is reserved
 *      successfully, ib_kaddr will have the CPU/kernel
 *      address. Check ib_kaddr before accessing the memory.
 */
static int kfd_process_device_reserve_ib_mem(struct kfd_process_device *pdd)
{
        struct qcm_process_device *qpd = &pdd->qpd;
        uint32_t flags = ALLOC_MEM_FLAGS_GTT |
                         ALLOC_MEM_FLAGS_NO_SUBSTITUTE |
                         ALLOC_MEM_FLAGS_WRITABLE |
                         ALLOC_MEM_FLAGS_EXECUTABLE;
        void *kaddr;
        int ret;

        if (qpd->ib_kaddr || !qpd->ib_base)
                return 0;

        /* ib_base is only set for dGPU */
        ret = kfd_process_alloc_gpuvm(pdd, qpd->ib_base, PAGE_SIZE, flags,
                                      &kaddr);
        if (ret)
                return ret;

        qpd->ib_kaddr = kaddr;

        return 0;
}

struct kfd_process *kfd_create_process(struct file *filep)
{
        struct kfd_process *process;
        struct task_struct *thread = current;
        int ret;

        if (!thread->mm)
                return ERR_PTR(-EINVAL);

        /* Only the pthreads threading model is supported. */
        if (thread->group_leader->mm != thread->mm)
                return ERR_PTR(-EINVAL);

        /*
         * take kfd processes mutex before starting of process creation
         * so there won't be a case where two threads of the same process
         * create two kfd_process structures
         */
        mutex_lock(&kfd_processes_mutex);

        /* A prior open of /dev/kfd could have already created the process. */
        process = find_process(thread);
        if (process) {
                pr_debug("Process already found\n");
        } else {
                process = create_process(thread, filep);

                if (!procfs.kobj)
                        goto out;

                process->kobj = kfd_alloc_struct(process->kobj);
                if (!process->kobj) {
                        pr_warn("Creating procfs kobject failed");
                        goto out;
                }
                ret = kobject_init_and_add(process->kobj, &procfs_type,
                                           procfs.kobj, "%d",
                                           (int)process->lead_thread->pid);
                if (ret) {
                        pr_warn("Creating procfs pid directory failed");
                        goto out;
                }

                process->attr_pasid.name = "pasid";
                process->attr_pasid.mode = KFD_SYSFS_FILE_MODE;
                sysfs_attr_init(&process->attr_pasid);
                ret = sysfs_create_file(process->kobj, &process->attr_pasid);
                if (ret)
                        pr_warn("Creating pasid for pid %d failed",
                                        (int)process->lead_thread->pid);
        }
out:
        mutex_unlock(&kfd_processes_mutex);

        return process;
}

struct kfd_process *kfd_get_process(const struct task_struct *thread)
{
        struct kfd_process *process;

        if (!thread->mm)
                return ERR_PTR(-EINVAL);

        /* Only the pthreads threading model is supported. */
        if (thread->group_leader->mm != thread->mm)
                return ERR_PTR(-EINVAL);

        process = find_process(thread);
        if (!process)
                return ERR_PTR(-EINVAL);

        return process;
}

static struct kfd_process *find_process_by_mm(const struct mm_struct *mm)
{
        struct kfd_process *process;

        hash_for_each_possible_rcu(kfd_processes_table, process,
                                        kfd_processes, (uintptr_t)mm)
                if (process->mm == mm)
                        return process;

        return NULL;
}

static struct kfd_process *find_process(const struct task_struct *thread)
{
        struct kfd_process *p;
        int idx;

        idx = srcu_read_lock(&kfd_processes_srcu);
        p = find_process_by_mm(thread->mm);
        srcu_read_unlock(&kfd_processes_srcu, idx);

        return p;
}

void kfd_unref_process(struct kfd_process *p)
{
        kref_put(&p->ref, kfd_process_ref_release);
}

static void kfd_process_device_free_bos(struct kfd_process_device *pdd)
{
        struct kfd_process *p = pdd->process;
        void *mem;
        int id;

        /*
         * Remove all handles from idr and release appropriate
         * local memory object
         */
        idr_for_each_entry(&pdd->alloc_idr, mem, id) {
                struct kfd_process_device *peer_pdd;

                list_for_each_entry(peer_pdd, &p->per_device_data,
                                    per_device_list) {
                        if (!peer_pdd->vm)
                                continue;
                        amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
                                peer_pdd->dev->kgd, mem, peer_pdd->vm);
                }

                amdgpu_amdkfd_gpuvm_free_memory_of_gpu(pdd->dev->kgd, mem);
                kfd_process_device_remove_obj_handle(pdd, id);
        }
}

static void kfd_process_free_outstanding_kfd_bos(struct kfd_process *p)
{
        struct kfd_process_device *pdd;

        list_for_each_entry(pdd, &p->per_device_data, per_device_list)
                kfd_process_device_free_bos(pdd);
}

static void kfd_process_destroy_pdds(struct kfd_process *p)
{
        struct kfd_process_device *pdd, *temp;

        list_for_each_entry_safe(pdd, temp, &p->per_device_data,
                                 per_device_list) {
                pr_debug("Releasing pdd (topology id %d) for process (pasid %d)\n",
                                pdd->dev->id, p->pasid);

                if (pdd->drm_file) {
                        amdgpu_amdkfd_gpuvm_release_process_vm(
                                        pdd->dev->kgd, pdd->vm);
                        fput(pdd->drm_file);
                }
                else if (pdd->vm)
                        amdgpu_amdkfd_gpuvm_destroy_process_vm(
                                pdd->dev->kgd, pdd->vm);

                list_del(&pdd->per_device_list);

                if (pdd->qpd.cwsr_kaddr && !pdd->qpd.cwsr_base)
                        free_pages((unsigned long)pdd->qpd.cwsr_kaddr,
                                get_order(KFD_CWSR_TBA_TMA_SIZE));

                kfree(pdd->qpd.doorbell_bitmap);
                idr_destroy(&pdd->alloc_idr);

                kfree(pdd);
        }
}

/* No process locking is needed in this function, because the process
 * is not findable any more. We must assume that no other thread is
 * using it any more, otherwise we couldn't safely free the process
 * structure in the end.
 */
static void kfd_process_wq_release(struct work_struct *work)
{
        struct kfd_process *p = container_of(work, struct kfd_process,
                                             release_work);

        /* Remove the procfs files */
        if (p->kobj) {
                sysfs_remove_file(p->kobj, &p->attr_pasid);
                kobject_del(p->kobj);
                kobject_put(p->kobj);
                p->kobj = NULL;
        }

        kfd_iommu_unbind_process(p);

        kfd_process_free_outstanding_kfd_bos(p);

        kfd_process_destroy_pdds(p);
        dma_fence_put(p->ef);

        kfd_event_free_process(p);

        kfd_pasid_free(p->pasid);
        kfd_free_process_doorbells(p);

        mutex_destroy(&p->mutex);

        put_task_struct(p->lead_thread);

        kfree(p);
}

static void kfd_process_ref_release(struct kref *ref)
{
        struct kfd_process *p = container_of(ref, struct kfd_process, ref);

        INIT_WORK(&p->release_work, kfd_process_wq_release);
        queue_work(kfd_process_wq, &p->release_work);
}

static void kfd_process_destroy_delayed(struct rcu_head *rcu)
{
        struct kfd_process *p = container_of(rcu, struct kfd_process, rcu);

        kfd_unref_process(p);
}

static void kfd_process_notifier_release(struct mmu_notifier *mn,
                                        struct mm_struct *mm)
{
        struct kfd_process *p;
        struct kfd_process_device *pdd = NULL;

        /*
         * The kfd_process structure can not be free because the
         * mmu_notifier srcu is read locked
         */
        p = container_of(mn, struct kfd_process, mmu_notifier);
        if (WARN_ON(p->mm != mm))
                return;

        mutex_lock(&kfd_processes_mutex);
        hash_del_rcu(&p->kfd_processes);
        mutex_unlock(&kfd_processes_mutex);
        synchronize_srcu(&kfd_processes_srcu);

        cancel_delayed_work_sync(&p->eviction_work);
        cancel_delayed_work_sync(&p->restore_work);

        mutex_lock(&p->mutex);

        /* Iterate over all process device data structures and if the
         * pdd is in debug mode, we should first force unregistration,
         * then we will be able to destroy the queues
         */
        list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
                struct kfd_dev *dev = pdd->dev;

                mutex_lock(kfd_get_dbgmgr_mutex());
                if (dev && dev->dbgmgr && dev->dbgmgr->pasid == p->pasid) {
                        if (!kfd_dbgmgr_unregister(dev->dbgmgr, p)) {
                                kfd_dbgmgr_destroy(dev->dbgmgr);
                                dev->dbgmgr = NULL;
                        }
                }
                mutex_unlock(kfd_get_dbgmgr_mutex());
        }

        kfd_process_dequeue_from_all_devices(p);
        pqm_uninit(&p->pqm);

        /* Indicate to other users that MM is no longer valid */
        p->mm = NULL;

        mutex_unlock(&p->mutex);

        mmu_notifier_unregister_no_release(&p->mmu_notifier, mm);
        mmu_notifier_call_srcu(&p->rcu, &kfd_process_destroy_delayed);
}

static const struct mmu_notifier_ops kfd_process_mmu_notifier_ops = {
        .release = kfd_process_notifier_release,
};

static int kfd_process_init_cwsr_apu(struct kfd_process *p, struct file *filep)
{
        unsigned long  offset;
        struct kfd_process_device *pdd;

        list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
                struct kfd_dev *dev = pdd->dev;
                struct qcm_process_device *qpd = &pdd->qpd;

                if (!dev->cwsr_enabled || qpd->cwsr_kaddr || qpd->cwsr_base)
                        continue;

                offset = (KFD_MMAP_TYPE_RESERVED_MEM | KFD_MMAP_GPU_ID(dev->id))
                        << PAGE_SHIFT;
                qpd->tba_addr = (int64_t)vm_mmap(filep, 0,
                        KFD_CWSR_TBA_TMA_SIZE, PROT_READ | PROT_EXEC,
                        MAP_SHARED, offset);

                if (IS_ERR_VALUE(qpd->tba_addr)) {
                        int err = qpd->tba_addr;

                        pr_err("Failure to set tba address. error %d.\n", err);
                        qpd->tba_addr = 0;
                        qpd->cwsr_kaddr = NULL;
                        return err;
                }

                memcpy(qpd->cwsr_kaddr, dev->cwsr_isa, dev->cwsr_isa_size);

                qpd->tma_addr = qpd->tba_addr + KFD_CWSR_TMA_OFFSET;
                pr_debug("set tba :0x%llx, tma:0x%llx, cwsr_kaddr:%p for pqm.\n",
                        qpd->tba_addr, qpd->tma_addr, qpd->cwsr_kaddr);
        }

        return 0;
}

static int kfd_process_device_init_cwsr_dgpu(struct kfd_process_device *pdd)
{
        struct kfd_dev *dev = pdd->dev;
        struct qcm_process_device *qpd = &pdd->qpd;
        uint32_t flags = ALLOC_MEM_FLAGS_GTT |
                ALLOC_MEM_FLAGS_NO_SUBSTITUTE | ALLOC_MEM_FLAGS_EXECUTABLE;
        void *kaddr;
        int ret;

        if (!dev->cwsr_enabled || qpd->cwsr_kaddr || !qpd->cwsr_base)
                return 0;

        /* cwsr_base is only set for dGPU */
        ret = kfd_process_alloc_gpuvm(pdd, qpd->cwsr_base,
                                      KFD_CWSR_TBA_TMA_SIZE, flags, &kaddr);
        if (ret)
                return ret;

        qpd->cwsr_kaddr = kaddr;
        qpd->tba_addr = qpd->cwsr_base;

        memcpy(qpd->cwsr_kaddr, dev->cwsr_isa, dev->cwsr_isa_size);

        qpd->tma_addr = qpd->tba_addr + KFD_CWSR_TMA_OFFSET;
        pr_debug("set tba :0x%llx, tma:0x%llx, cwsr_kaddr:%p for pqm.\n",
                 qpd->tba_addr, qpd->tma_addr, qpd->cwsr_kaddr);

        return 0;
}

static struct kfd_process *create_process(const struct task_struct *thread,
                                        struct file *filep)
{
        struct kfd_process *process;
        int err = -ENOMEM;

        process = kzalloc(sizeof(*process), GFP_KERNEL);

        if (!process)
                goto err_alloc_process;

        process->pasid = kfd_pasid_alloc();
        if (process->pasid == 0)
                goto err_alloc_pasid;

        if (kfd_alloc_process_doorbells(process) < 0)
                goto err_alloc_doorbells;

        kref_init(&process->ref);

        mutex_init(&process->mutex);

        process->mm = thread->mm;

        /* register notifier */
        process->mmu_notifier.ops = &kfd_process_mmu_notifier_ops;
        err = mmu_notifier_register(&process->mmu_notifier, process->mm);
        if (err)
                goto err_mmu_notifier;

        hash_add_rcu(kfd_processes_table, &process->kfd_processes,
                        (uintptr_t)process->mm);

        process->lead_thread = thread->group_leader;
        get_task_struct(process->lead_thread);

        INIT_LIST_HEAD(&process->per_device_data);

        kfd_event_init_process(process);

        err = pqm_init(&process->pqm, process);
        if (err != 0)
                goto err_process_pqm_init;

        /* init process apertures*/
        process->is_32bit_user_mode = in_compat_syscall();
        err = kfd_init_apertures(process);
        if (err != 0)
                goto err_init_apertures;

        INIT_DELAYED_WORK(&process->eviction_work, evict_process_worker);
        INIT_DELAYED_WORK(&process->restore_work, restore_process_worker);
        process->last_restore_timestamp = get_jiffies_64();

        err = kfd_process_init_cwsr_apu(process, filep);
        if (err)
                goto err_init_cwsr;

        return process;

err_init_cwsr:
        kfd_process_free_outstanding_kfd_bos(process);
        kfd_process_destroy_pdds(process);
err_init_apertures:
        pqm_uninit(&process->pqm);
err_process_pqm_init:
        hash_del_rcu(&process->kfd_processes);
        synchronize_rcu();
        mmu_notifier_unregister_no_release(&process->mmu_notifier, process->mm);
err_mmu_notifier:
        mutex_destroy(&process->mutex);
        kfd_free_process_doorbells(process);
err_alloc_doorbells:
        kfd_pasid_free(process->pasid);
err_alloc_pasid:
        kfree(process);
err_alloc_process:
        return ERR_PTR(err);
}

static int init_doorbell_bitmap(struct qcm_process_device *qpd,
                        struct kfd_dev *dev)
{
        unsigned int i;

        if (!KFD_IS_SOC15(dev->device_info->asic_family))
                return 0;

        qpd->doorbell_bitmap =
                kzalloc(DIV_ROUND_UP(KFD_MAX_NUM_OF_QUEUES_PER_PROCESS,
                                     BITS_PER_BYTE), GFP_KERNEL);
        if (!qpd->doorbell_bitmap)
                return -ENOMEM;

        /* Mask out doorbells reserved for SDMA, IH, and VCN on SOC15. */
        for (i = 0; i < KFD_MAX_NUM_OF_QUEUES_PER_PROCESS / 2; i++) {
                if (i >= dev->shared_resources.non_cp_doorbells_start
                        && i <= dev->shared_resources.non_cp_doorbells_end) {
                        set_bit(i, qpd->doorbell_bitmap);
                        set_bit(i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET,
                                qpd->doorbell_bitmap);
                        pr_debug("reserved doorbell 0x%03x and 0x%03x\n", i,
                                i + KFD_QUEUE_DOORBELL_MIRROR_OFFSET);
                }
        }

        return 0;
}

struct kfd_process_device *kfd_get_process_device_data(struct kfd_dev *dev,
                                                        struct kfd_process *p)
{
        struct kfd_process_device *pdd = NULL;

        list_for_each_entry(pdd, &p->per_device_data, per_device_list)
                if (pdd->dev == dev)
                        return pdd;

        return NULL;
}

struct kfd_process_device *kfd_create_process_device_data(struct kfd_dev *dev,
                                                        struct kfd_process *p)
{
        struct kfd_process_device *pdd = NULL;

        pdd = kzalloc(sizeof(*pdd), GFP_KERNEL);
        if (!pdd)
                return NULL;

        if (init_doorbell_bitmap(&pdd->qpd, dev)) {
                pr_err("Failed to init doorbell for process\n");
                kfree(pdd);
                return NULL;
        }

        pdd->dev = dev;
        INIT_LIST_HEAD(&pdd->qpd.queues_list);
        INIT_LIST_HEAD(&pdd->qpd.priv_queue_list);
        pdd->qpd.dqm = dev->dqm;
        pdd->qpd.pqm = &p->pqm;
        pdd->qpd.evicted = 0;
        pdd->process = p;
        pdd->bound = PDD_UNBOUND;
        pdd->already_dequeued = false;
        list_add(&pdd->per_device_list, &p->per_device_data);

        /* Init idr used for memory handle translation */
        idr_init(&pdd->alloc_idr);

        return pdd;
}

/**
 * kfd_process_device_init_vm - Initialize a VM for a process-device
 *
 * @pdd: The process-device
 * @drm_file: Optional pointer to a DRM file descriptor
 *
 * If @drm_file is specified, it will be used to acquire the VM from
 * that file descriptor. If successful, the @pdd takes ownership of
 * the file descriptor.
 *
 * If @drm_file is NULL, a new VM is created.
 *
 * Returns 0 on success, -errno on failure.
 */
int kfd_process_device_init_vm(struct kfd_process_device *pdd,
                               struct file *drm_file)
{
        struct kfd_process *p;
        struct kfd_dev *dev;
        int ret;

        if (pdd->vm)
                return drm_file ? -EBUSY : 0;

        p = pdd->process;
        dev = pdd->dev;

        if (drm_file)
                ret = amdgpu_amdkfd_gpuvm_acquire_process_vm(
                        dev->kgd, drm_file, p->pasid,
                        &pdd->vm, &p->kgd_process_info, &p->ef);
        else
                ret = amdgpu_amdkfd_gpuvm_create_process_vm(dev->kgd, p->pasid,
                        &pdd->vm, &p->kgd_process_info, &p->ef);
        if (ret) {
                pr_err("Failed to create process VM object\n");
                return ret;
        }

        ret = kfd_process_device_reserve_ib_mem(pdd);
        if (ret)
                goto err_reserve_ib_mem;
        ret = kfd_process_device_init_cwsr_dgpu(pdd);
        if (ret)
                goto err_init_cwsr;

        pdd->drm_file = drm_file;

        return 0;

err_init_cwsr:
err_reserve_ib_mem:
        kfd_process_device_free_bos(pdd);
        if (!drm_file)
                amdgpu_amdkfd_gpuvm_destroy_process_vm(dev->kgd, pdd->vm);
        pdd->vm = NULL;

        return ret;
}

/*
 * Direct the IOMMU to bind the process (specifically the pasid->mm)
 * to the device.
 * Unbinding occurs when the process dies or the device is removed.
 *
 * Assumes that the process lock is held.
 */
struct kfd_process_device *kfd_bind_process_to_device(struct kfd_dev *dev,
                                                        struct kfd_process *p)
{
        struct kfd_process_device *pdd;
        int err;

        pdd = kfd_get_process_device_data(dev, p);
        if (!pdd) {
                pr_err("Process device data doesn't exist\n");
                return ERR_PTR(-ENOMEM);
        }

        err = kfd_iommu_bind_process_to_device(pdd);
        if (err)
                return ERR_PTR(err);

        err = kfd_process_device_init_vm(pdd, NULL);
        if (err)
                return ERR_PTR(err);

        return pdd;
}

struct kfd_process_device *kfd_get_first_process_device_data(
                                                struct kfd_process *p)
{
        return list_first_entry(&p->per_device_data,
                                struct kfd_process_device,
                                per_device_list);
}

struct kfd_process_device *kfd_get_next_process_device_data(
                                                struct kfd_process *p,
                                                struct kfd_process_device *pdd)
{
        if (list_is_last(&pdd->per_device_list, &p->per_device_data))
                return NULL;
        return list_next_entry(pdd, per_device_list);
}

bool kfd_has_process_device_data(struct kfd_process *p)
{
        return !(list_empty(&p->per_device_data));
}

/* Create specific handle mapped to mem from process local memory idr
 * Assumes that the process lock is held.
 */
int kfd_process_device_create_obj_handle(struct kfd_process_device *pdd,
                                        void *mem)
{
        return idr_alloc(&pdd->alloc_idr, mem, 0, 0, GFP_KERNEL);
}

/* Translate specific handle from process local memory idr
 * Assumes that the process lock is held.
 */
void *kfd_process_device_translate_handle(struct kfd_process_device *pdd,
                                        int handle)
{
        if (handle < 0)
                return NULL;

        return idr_find(&pdd->alloc_idr, handle);
}

/* Remove specific handle from process local memory idr
 * Assumes that the process lock is held.
 */
void kfd_process_device_remove_obj_handle(struct kfd_process_device *pdd,
                                        int handle)
{
        if (handle >= 0)
                idr_remove(&pdd->alloc_idr, handle);
}

/* This increments the process->ref counter. */
struct kfd_process *kfd_lookup_process_by_pasid(unsigned int pasid)
{
        struct kfd_process *p, *ret_p = NULL;
        unsigned int temp;

        int idx = srcu_read_lock(&kfd_processes_srcu);

        hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
                if (p->pasid == pasid) {
                        kref_get(&p->ref);
                        ret_p = p;
                        break;
                }
        }

        srcu_read_unlock(&kfd_processes_srcu, idx);

        return ret_p;
}

/* This increments the process->ref counter. */
struct kfd_process *kfd_lookup_process_by_mm(const struct mm_struct *mm)
{
        struct kfd_process *p;

        int idx = srcu_read_lock(&kfd_processes_srcu);

        p = find_process_by_mm(mm);
        if (p)
                kref_get(&p->ref);

        srcu_read_unlock(&kfd_processes_srcu, idx);

        return p;
}

/* process_evict_queues - Evict all user queues of a process
 *
 * Eviction is reference-counted per process-device. This means multiple
 * evictions from different sources can be nested safely.
 */
int kfd_process_evict_queues(struct kfd_process *p)
{
        struct kfd_process_device *pdd;
        int r = 0;
        unsigned int n_evicted = 0;

        list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
                r = pdd->dev->dqm->ops.evict_process_queues(pdd->dev->dqm,
                                                            &pdd->qpd);
                if (r) {
                        pr_err("Failed to evict process queues\n");
                        goto fail;
                }
                n_evicted++;
        }

        return r;

fail:
        /* To keep state consistent, roll back partial eviction by
         * restoring queues
         */
        list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
                if (n_evicted == 0)
                        break;
                if (pdd->dev->dqm->ops.restore_process_queues(pdd->dev->dqm,
                                                              &pdd->qpd))
                        pr_err("Failed to restore queues\n");

                n_evicted--;
        }

        return r;
}

/* process_restore_queues - Restore all user queues of a process */
int kfd_process_restore_queues(struct kfd_process *p)
{
        struct kfd_process_device *pdd;
        int r, ret = 0;

        list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
                r = pdd->dev->dqm->ops.restore_process_queues(pdd->dev->dqm,
                                                              &pdd->qpd);
                if (r) {
                        pr_err("Failed to restore process queues\n");
                        if (!ret)
                                ret = r;
                }
        }

        return ret;
}

static void evict_process_worker(struct work_struct *work)
{
        int ret;
        struct kfd_process *p;
        struct delayed_work *dwork;

        dwork = to_delayed_work(work);

        /* Process termination destroys this worker thread. So during the
         * lifetime of this thread, kfd_process p will be valid
         */
        p = container_of(dwork, struct kfd_process, eviction_work);
        WARN_ONCE(p->last_eviction_seqno != p->ef->seqno,
                  "Eviction fence mismatch\n");

        /* Narrow window of overlap between restore and evict work
         * item is possible. Once amdgpu_amdkfd_gpuvm_restore_process_bos
         * unreserves KFD BOs, it is possible to evicted again. But
         * restore has few more steps of finish. So lets wait for any
         * previous restore work to complete
         */
        flush_delayed_work(&p->restore_work);

        pr_debug("Started evicting pasid %d\n", p->pasid);
        ret = kfd_process_evict_queues(p);
        if (!ret) {
                dma_fence_signal(p->ef);
                dma_fence_put(p->ef);
                p->ef = NULL;
                queue_delayed_work(kfd_restore_wq, &p->restore_work,
                                msecs_to_jiffies(PROCESS_RESTORE_TIME_MS));

                pr_debug("Finished evicting pasid %d\n", p->pasid);
        } else
                pr_err("Failed to evict queues of pasid %d\n", p->pasid);
}

static void restore_process_worker(struct work_struct *work)
{
        struct delayed_work *dwork;
        struct kfd_process *p;
        struct kfd_process_device *pdd;
        int ret = 0;

        dwork = to_delayed_work(work);

        /* Process termination destroys this worker thread. So during the
         * lifetime of this thread, kfd_process p will be valid
         */
        p = container_of(dwork, struct kfd_process, restore_work);

        /* Call restore_process_bos on the first KGD device. This function
         * takes care of restoring the whole process including other devices.
         * Restore can fail if enough memory is not available. If so,
         * reschedule again.
         */
        pdd = list_first_entry(&p->per_device_data,
                               struct kfd_process_device,
                               per_device_list);

        pr_debug("Started restoring pasid %d\n", p->pasid);

        /* Setting last_restore_timestamp before successful restoration.
         * Otherwise this would have to be set by KGD (restore_process_bos)
         * before KFD BOs are unreserved. If not, the process can be evicted
         * again before the timestamp is set.
         * If restore fails, the timestamp will be set again in the next
         * attempt. This would mean that the minimum GPU quanta would be
         * PROCESS_ACTIVE_TIME_MS - (time to execute the following two
         * functions)
         */

        p->last_restore_timestamp = get_jiffies_64();
        ret = amdgpu_amdkfd_gpuvm_restore_process_bos(p->kgd_process_info,
                                                     &p->ef);
        if (ret) {
                pr_debug("Failed to restore BOs of pasid %d, retry after %d ms\n",
                         p->pasid, PROCESS_BACK_OFF_TIME_MS);
                ret = queue_delayed_work(kfd_restore_wq, &p->restore_work,
                                msecs_to_jiffies(PROCESS_BACK_OFF_TIME_MS));
                WARN(!ret, "reschedule restore work failed\n");
                return;
        }

        ret = kfd_process_restore_queues(p);
        if (!ret)
                pr_debug("Finished restoring pasid %d\n", p->pasid);
        else
                pr_err("Failed to restore queues of pasid %d\n", p->pasid);
}

void kfd_suspend_all_processes(void)
{
        struct kfd_process *p;
        unsigned int temp;
        int idx = srcu_read_lock(&kfd_processes_srcu);

        hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
                cancel_delayed_work_sync(&p->eviction_work);
                cancel_delayed_work_sync(&p->restore_work);

                if (kfd_process_evict_queues(p))
                        pr_err("Failed to suspend process %d\n", p->pasid);
                dma_fence_signal(p->ef);
                dma_fence_put(p->ef);
                p->ef = NULL;
        }
        srcu_read_unlock(&kfd_processes_srcu, idx);
}

int kfd_resume_all_processes(void)
{
        struct kfd_process *p;
        unsigned int temp;
        int ret = 0, idx = srcu_read_lock(&kfd_processes_srcu);

        hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
                if (!queue_delayed_work(kfd_restore_wq, &p->restore_work, 0)) {
                        pr_err("Restore process %d failed during resume\n",
                               p->pasid);
                        ret = -EFAULT;
                }
        }
        srcu_read_unlock(&kfd_processes_srcu, idx);
        return ret;
}

int kfd_reserved_mem_mmap(struct kfd_dev *dev, struct kfd_process *process,
                          struct vm_area_struct *vma)
{
        struct kfd_process_device *pdd;
        struct qcm_process_device *qpd;

        if ((vma->vm_end - vma->vm_start) != KFD_CWSR_TBA_TMA_SIZE) {
                pr_err("Incorrect CWSR mapping size.\n");
                return -EINVAL;
        }

        pdd = kfd_get_process_device_data(dev, process);
        if (!pdd)
                return -EINVAL;
        qpd = &pdd->qpd;

        qpd->cwsr_kaddr = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
                                        get_order(KFD_CWSR_TBA_TMA_SIZE));
        if (!qpd->cwsr_kaddr) {
                pr_err("Error allocating per process CWSR buffer.\n");
                return -ENOMEM;
        }

        vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND
                | VM_NORESERVE | VM_DONTDUMP | VM_PFNMAP;
        /* Mapping pages to user process */
        return remap_pfn_range(vma, vma->vm_start,
                               PFN_DOWN(__pa(qpd->cwsr_kaddr)),
                               KFD_CWSR_TBA_TMA_SIZE, vma->vm_page_prot);
}

void kfd_flush_tlb(struct kfd_process_device *pdd)
{
        struct kfd_dev *dev = pdd->dev;
        const struct kfd2kgd_calls *f2g = dev->kfd2kgd;

        if (dev->dqm->sched_policy == KFD_SCHED_POLICY_NO_HWS) {
                /* Nothing to flush until a VMID is assigned, which
                 * only happens when the first queue is created.
                 */
                if (pdd->qpd.vmid)
                        f2g->invalidate_tlbs_vmid(dev->kgd, pdd->qpd.vmid);
        } else {
                f2g->invalidate_tlbs(dev->kgd, pdd->process->pasid);
        }
}

#if defined(CONFIG_DEBUG_FS)

int kfd_debugfs_mqds_by_process(struct seq_file *m, void *data)
{
        struct kfd_process *p;
        unsigned int temp;
        int r = 0;

        int idx = srcu_read_lock(&kfd_processes_srcu);

        hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
                seq_printf(m, "Process %d PASID %d:\n",
                           p->lead_thread->tgid, p->pasid);

                mutex_lock(&p->mutex);
                r = pqm_debugfs_mqds(m, &p->pqm);
                mutex_unlock(&p->mutex);

                if (r)
                        break;
        }

        srcu_read_unlock(&kfd_processes_srcu, idx);

        return r;
}

#endif