/*
 * Copyright 2008 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 * Copyright 2009 Jerome Glisse.
 *
 * 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.
 *
 * Authors: Dave Airlie
 *          Alex Deucher
 *          Jerome Glisse
 */
#include <linux/dma-fence-array.h>
#include <linux/interval_tree_generic.h>
#include <linux/idr.h>
#include <drm/drmP.h>
#include <drm/amdgpu_drm.h>
#include "amdgpu.h"
#include "amdgpu_trace.h"
#include "amdgpu_amdkfd.h"
#include "amdgpu_gmc.h"

#include <linux/rbtree.h>
#include "amdgpu_vm.h"

/**
 * DOC: GPUVM
 *
 * GPUVM is similar to the legacy gart on older asics, however
 * rather than there being a single global gart table
 * for the entire GPU, there are multiple VM page tables active
 * at any given time.  The VM page tables can contain a mix
 * vram pages and system memory pages and system memory pages
 * can be mapped as snooped (cached system pages) or unsnooped
 * (uncached system pages).
 * Each VM has an ID associated with it and there is a page table
 * associated with each VMID.  When execting a command buffer,
 * the kernel tells the the ring what VMID to use for that command
 * buffer.  VMIDs are allocated dynamically as commands are submitted.
 * The userspace drivers maintain their own address space and the kernel
 * sets up their pages tables accordingly when they submit their
 * command buffers and a VMID is assigned.
 * Cayman/Trinity support up to 8 active VMs at any given time;
 * SI supports 16.
 */

#define START(node) ((node)->start)
#define LAST(node) ((node)->last)

#ifdef __linux__

INTERVAL_TREE_DEFINE(struct amdgpu_bo_va_mapping, rb, uint64_t, __subtree_last,
                     START, LAST, static, amdgpu_vm_it)
#else
static struct amdgpu_bo_va_mapping *
amdgpu_vm_it_iter_first(struct rb_root_cached *root, uint64_t start,
    uint64_t last)
{
        struct amdgpu_bo_va_mapping *node;
        struct rb_node *rb;

        for (rb = rb_first_cached(root); rb; rb = rb_next(rb)) {
                node = rb_entry(rb, typeof(*node), rb);
                if (LAST(node) >= start && START(node) <= last)
                        return node;
        }
        return NULL;
}

static struct amdgpu_bo_va_mapping *
amdgpu_vm_it_iter_next(struct amdgpu_bo_va_mapping *node, uint64_t start,
    uint64_t last)
{
        STUB();
        struct rb_node *rb = &node->rb;

        for (rb = rb_next(rb); rb; rb = rb_next(rb)) {
                node = rb_entry(rb, typeof(*node), rb);
                if (LAST(node) >= start && START(node) <= last)
                        return node;
        }
        return NULL;
}

static void
amdgpu_vm_it_remove(struct amdgpu_bo_va_mapping *node,
    struct rb_root_cached *root) 
{
        rb_erase_cached(&node->rb, root);
}

static void
amdgpu_vm_it_insert(struct amdgpu_bo_va_mapping *node,
    struct rb_root_cached *root)
{
        struct rb_node **iter = &root->rb_root.rb_node;
        struct rb_node *parent = NULL;
        struct amdgpu_bo_va_mapping *iter_node;

        while (*iter) {
                parent = *iter;
                iter_node = rb_entry(*iter, struct amdgpu_bo_va_mapping, rb);

                if (node->start < iter_node->start)
                        iter = &(*iter)->rb_left;
                else
                        iter = &(*iter)->rb_right;
        }

        rb_link_node(&node->rb, parent, iter);
        rb_insert_color_cached(&node->rb, root, false);
}
#endif

#undef START
#undef LAST

/**
 * struct amdgpu_pte_update_params - Local structure
 *
 * Encapsulate some VM table update parameters to reduce
 * the number of function parameters
 *
 */
struct amdgpu_pte_update_params {

        /**
         * @adev: amdgpu device we do this update for
         */
        struct amdgpu_device *adev;

        /**
         * @vm: optional amdgpu_vm we do this update for
         */
        struct amdgpu_vm *vm;

        /**
         * @src: address where to copy page table entries from
         */
        uint64_t src;

        /**
         * @ib: indirect buffer to fill with commands
         */
        struct amdgpu_ib *ib;

        /**
         * @func: Function which actually does the update
         */
        void (*func)(struct amdgpu_pte_update_params *params,
                     struct amdgpu_bo *bo, uint64_t pe,
                     uint64_t addr, unsigned count, uint32_t incr,
                     uint64_t flags);
        /**
         * @pages_addr:
         *
         * DMA addresses to use for mapping, used during VM update by CPU
         */
        dma_addr_t *pages_addr;

        /**
         * @kptr:
         *
         * Kernel pointer of PD/PT BO that needs to be updated,
         * used during VM update by CPU
         */
        void *kptr;
};

/**
 * struct amdgpu_prt_cb - Helper to disable partial resident texture feature from a fence callback
 */
struct amdgpu_prt_cb {

        /**
         * @adev: amdgpu device
         */
        struct amdgpu_device *adev;

        /**
         * @cb: callback
         */
        struct dma_fence_cb cb;
};

/**
 * amdgpu_vm_level_shift - return the addr shift for each level
 *
 * @adev: amdgpu_device pointer
 * @level: VMPT level
 *
 * Returns:
 * The number of bits the pfn needs to be right shifted for a level.
 */
static unsigned amdgpu_vm_level_shift(struct amdgpu_device *adev,
                                      unsigned level)
{
        unsigned shift = 0xff;

        switch (level) {
        case AMDGPU_VM_PDB2:
        case AMDGPU_VM_PDB1:
        case AMDGPU_VM_PDB0:
                shift = 9 * (AMDGPU_VM_PDB0 - level) +
                        adev->vm_manager.block_size;
                break;
        case AMDGPU_VM_PTB:
                shift = 0;
                break;
        default:
                dev_err(adev->dev, "the level%d isn't supported.\n", level);
        }

        return shift;
}

/**
 * amdgpu_vm_num_entries - return the number of entries in a PD/PT
 *
 * @adev: amdgpu_device pointer
 * @level: VMPT level
 *
 * Returns:
 * The number of entries in a page directory or page table.
 */
static unsigned amdgpu_vm_num_entries(struct amdgpu_device *adev,
                                      unsigned level)
{
        unsigned shift = amdgpu_vm_level_shift(adev,
                                               adev->vm_manager.root_level);

        if (level == adev->vm_manager.root_level)
                /* For the root directory */
                return round_up(adev->vm_manager.max_pfn, 1ULL << shift) >> shift;
        else if (level != AMDGPU_VM_PTB)
                /* Everything in between */
                return 512;
        else
                /* For the page tables on the leaves */
                return AMDGPU_VM_PTE_COUNT(adev);
}

/**
 * amdgpu_vm_entries_mask - the mask to get the entry number of a PD/PT
 *
 * @adev: amdgpu_device pointer
 * @level: VMPT level
 *
 * Returns:
 * The mask to extract the entry number of a PD/PT from an address.
 */
static uint32_t amdgpu_vm_entries_mask(struct amdgpu_device *adev,
                                       unsigned int level)
{
        if (level <= adev->vm_manager.root_level)
                return 0xffffffff;
        else if (level != AMDGPU_VM_PTB)
                return 0x1ff;
        else
                return AMDGPU_VM_PTE_COUNT(adev) - 1;
}

/**
 * amdgpu_vm_bo_size - returns the size of the BOs in bytes
 *
 * @adev: amdgpu_device pointer
 * @level: VMPT level
 *
 * Returns:
 * The size of the BO for a page directory or page table in bytes.
 */
static unsigned amdgpu_vm_bo_size(struct amdgpu_device *adev, unsigned level)
{
        return AMDGPU_GPU_PAGE_ALIGN(amdgpu_vm_num_entries(adev, level) * 8);
}

/**
 * amdgpu_vm_bo_evicted - vm_bo is evicted
 *
 * @vm_bo: vm_bo which is evicted
 *
 * State for PDs/PTs and per VM BOs which are not at the location they should
 * be.
 */
static void amdgpu_vm_bo_evicted(struct amdgpu_vm_bo_base *vm_bo)
{
        struct amdgpu_vm *vm = vm_bo->vm;
        struct amdgpu_bo *bo = vm_bo->bo;

        vm_bo->moved = true;
        if (bo->tbo.type == ttm_bo_type_kernel)
                list_move(&vm_bo->vm_status, &vm->evicted);
        else
                list_move_tail(&vm_bo->vm_status, &vm->evicted);
}

/**
 * amdgpu_vm_bo_relocated - vm_bo is reloacted
 *
 * @vm_bo: vm_bo which is relocated
 *
 * State for PDs/PTs which needs to update their parent PD.
 */
static void amdgpu_vm_bo_relocated(struct amdgpu_vm_bo_base *vm_bo)
{
        list_move(&vm_bo->vm_status, &vm_bo->vm->relocated);
}

/**
 * amdgpu_vm_bo_moved - vm_bo is moved
 *
 * @vm_bo: vm_bo which is moved
 *
 * State for per VM BOs which are moved, but that change is not yet reflected
 * in the page tables.
 */
static void amdgpu_vm_bo_moved(struct amdgpu_vm_bo_base *vm_bo)
{
        list_move(&vm_bo->vm_status, &vm_bo->vm->moved);
}

/**
 * amdgpu_vm_bo_idle - vm_bo is idle
 *
 * @vm_bo: vm_bo which is now idle
 *
 * State for PDs/PTs and per VM BOs which have gone through the state machine
 * and are now idle.
 */
static void amdgpu_vm_bo_idle(struct amdgpu_vm_bo_base *vm_bo)
{
        list_move(&vm_bo->vm_status, &vm_bo->vm->idle);
        vm_bo->moved = false;
}

/**
 * amdgpu_vm_bo_invalidated - vm_bo is invalidated
 *
 * @vm_bo: vm_bo which is now invalidated
 *
 * State for normal BOs which are invalidated and that change not yet reflected
 * in the PTs.
 */
static void amdgpu_vm_bo_invalidated(struct amdgpu_vm_bo_base *vm_bo)
{
        lockmgr(&vm_bo->vm->invalidated_lock, LK_EXCLUSIVE);
        list_move(&vm_bo->vm_status, &vm_bo->vm->invalidated);
        lockmgr(&vm_bo->vm->invalidated_lock, LK_RELEASE);
}

/**
 * amdgpu_vm_bo_done - vm_bo is done
 *
 * @vm_bo: vm_bo which is now done
 *
 * State for normal BOs which are invalidated and that change has been updated
 * in the PTs.
 */
static void amdgpu_vm_bo_done(struct amdgpu_vm_bo_base *vm_bo)
{
        lockmgr(&vm_bo->vm->invalidated_lock, LK_EXCLUSIVE);
        list_del_init(&vm_bo->vm_status);
        lockmgr(&vm_bo->vm->invalidated_lock, LK_RELEASE);
}

/**
 * amdgpu_vm_bo_base_init - Adds bo to the list of bos associated with the vm
 *
 * @base: base structure for tracking BO usage in a VM
 * @vm: vm to which bo is to be added
 * @bo: amdgpu buffer object
 *
 * Initialize a bo_va_base structure and add it to the appropriate lists
 *
 */
static void amdgpu_vm_bo_base_init(struct amdgpu_vm_bo_base *base,
                                   struct amdgpu_vm *vm,
                                   struct amdgpu_bo *bo)
{
        base->vm = vm;
        base->bo = bo;
        base->next = NULL;
        INIT_LIST_HEAD(&base->vm_status);

        if (!bo)
                return;
        base->next = bo->vm_bo;
        bo->vm_bo = base;

        if (bo->tbo.resv != vm->root.base.bo->tbo.resv)
                return;

        vm->bulk_moveable = false;
        if (bo->tbo.type == ttm_bo_type_kernel)
                amdgpu_vm_bo_relocated(base);
        else
                amdgpu_vm_bo_idle(base);

        if (bo->preferred_domains &
            amdgpu_mem_type_to_domain(bo->tbo.mem.mem_type))
                return;

        /*
         * we checked all the prerequisites, but it looks like this per vm bo
         * is currently evicted. add the bo to the evicted list to make sure it
         * is validated on next vm use to avoid fault.
         * */
        amdgpu_vm_bo_evicted(base);
}

/**
 * amdgpu_vm_pt_parent - get the parent page directory
 *
 * @pt: child page table
 *
 * Helper to get the parent entry for the child page table. NULL if we are at
 * the root page directory.
 */
static struct amdgpu_vm_pt *amdgpu_vm_pt_parent(struct amdgpu_vm_pt *pt)
{
        struct amdgpu_bo *parent = pt->base.bo->parent;

        if (!parent)
                return NULL;

        return container_of(parent->vm_bo, struct amdgpu_vm_pt, base);
}

/**
 * amdgpu_vm_pt_cursor - state for for_each_amdgpu_vm_pt
 */
struct amdgpu_vm_pt_cursor {
        uint64_t pfn;
        struct amdgpu_vm_pt *parent;
        struct amdgpu_vm_pt *entry;
        unsigned level;
};

/**
 * amdgpu_vm_pt_start - start PD/PT walk
 *
 * @adev: amdgpu_device pointer
 * @vm: amdgpu_vm structure
 * @start: start address of the walk
 * @cursor: state to initialize
 *
 * Initialize a amdgpu_vm_pt_cursor to start a walk.
 */
static void amdgpu_vm_pt_start(struct amdgpu_device *adev,
                               struct amdgpu_vm *vm, uint64_t start,
                               struct amdgpu_vm_pt_cursor *cursor)
{
        cursor->pfn = start;
        cursor->parent = NULL;
        cursor->entry = &vm->root;
        cursor->level = adev->vm_manager.root_level;
}

/**
 * amdgpu_vm_pt_descendant - go to child node
 *
 * @adev: amdgpu_device pointer
 * @cursor: current state
 *
 * Walk to the child node of the current node.
 * Returns:
 * True if the walk was possible, false otherwise.
 */
static bool amdgpu_vm_pt_descendant(struct amdgpu_device *adev,
                                    struct amdgpu_vm_pt_cursor *cursor)
{
        unsigned mask, shift, idx;

        if (!cursor->entry->entries)
                return false;

        BUG_ON(!cursor->entry->base.bo);
        mask = amdgpu_vm_entries_mask(adev, cursor->level);
        shift = amdgpu_vm_level_shift(adev, cursor->level);

        ++cursor->level;
        idx = (cursor->pfn >> shift) & mask;
        cursor->parent = cursor->entry;
        cursor->entry = &cursor->entry->entries[idx];
        return true;
}

/**
 * amdgpu_vm_pt_sibling - go to sibling node
 *
 * @adev: amdgpu_device pointer
 * @cursor: current state
 *
 * Walk to the sibling node of the current node.
 * Returns:
 * True if the walk was possible, false otherwise.
 */
static bool amdgpu_vm_pt_sibling(struct amdgpu_device *adev,
                                 struct amdgpu_vm_pt_cursor *cursor)
{
        unsigned shift, num_entries;

        /* Root doesn't have a sibling */
        if (!cursor->parent)
                return false;

        /* Go to our parents and see if we got a sibling */
        shift = amdgpu_vm_level_shift(adev, cursor->level - 1);
        num_entries = amdgpu_vm_num_entries(adev, cursor->level - 1);

        if (cursor->entry == &cursor->parent->entries[num_entries - 1])
                return false;

        cursor->pfn += 1ULL << shift;
        cursor->pfn &= ~((1ULL << shift) - 1);
        ++cursor->entry;
        return true;
}

/**
 * amdgpu_vm_pt_ancestor - go to parent node
 *
 * @cursor: current state
 *
 * Walk to the parent node of the current node.
 * Returns:
 * True if the walk was possible, false otherwise.
 */
static bool amdgpu_vm_pt_ancestor(struct amdgpu_vm_pt_cursor *cursor)
{
        if (!cursor->parent)
                return false;

        --cursor->level;
        cursor->entry = cursor->parent;
        cursor->parent = amdgpu_vm_pt_parent(cursor->parent);
        return true;
}

/**
 * amdgpu_vm_pt_next - get next PD/PT in hieratchy
 *
 * @adev: amdgpu_device pointer
 * @cursor: current state
 *
 * Walk the PD/PT tree to the next node.
 */
static void amdgpu_vm_pt_next(struct amdgpu_device *adev,
                              struct amdgpu_vm_pt_cursor *cursor)
{
        /* First try a newborn child */
        if (amdgpu_vm_pt_descendant(adev, cursor))
                return;

        /* If that didn't worked try to find a sibling */
        while (!amdgpu_vm_pt_sibling(adev, cursor)) {
                /* No sibling, go to our parents and grandparents */
                if (!amdgpu_vm_pt_ancestor(cursor)) {
                        cursor->pfn = ~0ll;
                        return;
                }
        }
}

/**
 * amdgpu_vm_pt_first_leaf - get first leaf PD/PT
 *
 * @adev: amdgpu_device pointer
 * @vm: amdgpu_vm structure
 * @start: start addr of the walk
 * @cursor: state to initialize
 *
 * Start a walk and go directly to the leaf node.
 */
static void amdgpu_vm_pt_first_leaf(struct amdgpu_device *adev,
                                    struct amdgpu_vm *vm, uint64_t start,
                                    struct amdgpu_vm_pt_cursor *cursor)
{
        amdgpu_vm_pt_start(adev, vm, start, cursor);
        while (amdgpu_vm_pt_descendant(adev, cursor));
}

/**
 * amdgpu_vm_pt_next_leaf - get next leaf PD/PT
 *
 * @adev: amdgpu_device pointer
 * @cursor: current state
 *
 * Walk the PD/PT tree to the next leaf node.
 */
static void amdgpu_vm_pt_next_leaf(struct amdgpu_device *adev,
                                   struct amdgpu_vm_pt_cursor *cursor)
{
        amdgpu_vm_pt_next(adev, cursor);
        if (cursor->pfn != ~0ll)
                while (amdgpu_vm_pt_descendant(adev, cursor));
}

/**
 * for_each_amdgpu_vm_pt_leaf - walk over all leaf PDs/PTs in the hierarchy
 */
#define for_each_amdgpu_vm_pt_leaf(adev, vm, start, end, cursor)                \
        for (amdgpu_vm_pt_first_leaf((adev), (vm), (start), &(cursor));         \
             (cursor).pfn <= end; amdgpu_vm_pt_next_leaf((adev), &(cursor)))

/**
 * amdgpu_vm_pt_first_dfs - start a deep first search
 *
 * @adev: amdgpu_device structure
 * @vm: amdgpu_vm structure
 * @cursor: state to initialize
 *
 * Starts a deep first traversal of the PD/PT tree.
 */
static void amdgpu_vm_pt_first_dfs(struct amdgpu_device *adev,
                                   struct amdgpu_vm *vm,
                                   struct amdgpu_vm_pt_cursor *cursor)
{
        amdgpu_vm_pt_start(adev, vm, 0, cursor);
        while (amdgpu_vm_pt_descendant(adev, cursor));
}

/**
 * amdgpu_vm_pt_next_dfs - get the next node for a deep first search
 *
 * @adev: amdgpu_device structure
 * @cursor: current state
 *
 * Move the cursor to the next node in a deep first search.
 */
static void amdgpu_vm_pt_next_dfs(struct amdgpu_device *adev,
                                  struct amdgpu_vm_pt_cursor *cursor)
{
        if (!cursor->entry)
                return;

        if (!cursor->parent)
                cursor->entry = NULL;
        else if (amdgpu_vm_pt_sibling(adev, cursor))
                while (amdgpu_vm_pt_descendant(adev, cursor));
        else
                amdgpu_vm_pt_ancestor(cursor);
}

/**
 * for_each_amdgpu_vm_pt_dfs_safe - safe deep first search of all PDs/PTs
 */
#define for_each_amdgpu_vm_pt_dfs_safe(adev, vm, cursor, entry)                 \
        for (amdgpu_vm_pt_first_dfs((adev), (vm), &(cursor)),                   \
             (entry) = (cursor).entry, amdgpu_vm_pt_next_dfs((adev), &(cursor));\
             (entry); (entry) = (cursor).entry,                                 \
             amdgpu_vm_pt_next_dfs((adev), &(cursor)))

/**
 * amdgpu_vm_get_pd_bo - add the VM PD to a validation list
 *
 * @vm: vm providing the BOs
 * @validated: head of validation list
 * @entry: entry to add
 *
 * Add the page directory to the list of BOs to
 * validate for command submission.
 */
void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
                         struct list_head *validated,
                         struct amdgpu_bo_list_entry *entry)
{
        entry->priority = 0;
        entry->tv.bo = &vm->root.base.bo->tbo;
        entry->tv.shared = true;
        entry->user_pages = NULL;
        list_add(&entry->tv.head, validated);
}

/**
 * amdgpu_vm_move_to_lru_tail - move all BOs to the end of LRU
 *
 * @adev: amdgpu device pointer
 * @vm: vm providing the BOs
 *
 * Move all BOs to the end of LRU and remember their positions to put them
 * together.
 */
void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
                                struct amdgpu_vm *vm)
{
        struct ttm_bo_global *glob = adev->mman.bdev.glob;
        struct amdgpu_vm_bo_base *bo_base;

#if 0
        if (vm->bulk_moveable) {
                spin_lock(&glob->lru_lock);
                ttm_bo_bulk_move_lru_tail(&vm->lru_bulk_move);
                spin_unlock(&glob->lru_lock);
                return;
        }
#endif

        memset(&vm->lru_bulk_move, 0, sizeof(vm->lru_bulk_move));

        lockmgr(&glob->lru_lock, LK_EXCLUSIVE);
        list_for_each_entry(bo_base, &vm->idle, vm_status) {
                struct amdgpu_bo *bo = bo_base->bo;

                if (!bo->parent)
                        continue;

                ttm_bo_move_to_lru_tail(&bo->tbo, &vm->lru_bulk_move);
                if (bo->shadow)
                        ttm_bo_move_to_lru_tail(&bo->shadow->tbo,
                                                &vm->lru_bulk_move);
        }
        lockmgr(&glob->lru_lock, LK_RELEASE);

        vm->bulk_moveable = true;
}

/**
 * amdgpu_vm_validate_pt_bos - validate the page table BOs
 *
 * @adev: amdgpu device pointer
 * @vm: vm providing the BOs
 * @validate: callback to do the validation
 * @param: parameter for the validation callback
 *
 * Validate the page table BOs on command submission if neccessary.
 *
 * Returns:
 * Validation result.
 */
int amdgpu_vm_validate_pt_bos(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                              int (*validate)(void *p, struct amdgpu_bo *bo),
                              void *param)
{
        struct amdgpu_vm_bo_base *bo_base, *tmp;
        int r = 0;

        vm->bulk_moveable &= list_empty(&vm->evicted);

        list_for_each_entry_safe(bo_base, tmp, &vm->evicted, vm_status) {
                struct amdgpu_bo *bo = bo_base->bo;

                r = validate(param, bo);
                if (r)
                        break;

                if (bo->tbo.type != ttm_bo_type_kernel) {
                        amdgpu_vm_bo_moved(bo_base);
                } else {
                        if (vm->use_cpu_for_update)
                                r = amdgpu_bo_kmap(bo, NULL);
                        else
                                r = amdgpu_ttm_alloc_gart(&bo->tbo);
                        if (r)
                                break;
                        if (bo->shadow) {
                                r = amdgpu_ttm_alloc_gart(&bo->shadow->tbo);
                                if (r)
                                        break;
                        }
                        amdgpu_vm_bo_relocated(bo_base);
                }
        }

        return r;
}

/**
 * amdgpu_vm_ready - check VM is ready for updates
 *
 * @vm: VM to check
 *
 * Check if all VM PDs/PTs are ready for updates
 *
 * Returns:
 * True if eviction list is empty.
 */
bool amdgpu_vm_ready(struct amdgpu_vm *vm)
{
        return list_empty(&vm->evicted);
}

/**
 * amdgpu_vm_clear_bo - initially clear the PDs/PTs
 *
 * @adev: amdgpu_device pointer
 * @vm: VM to clear BO from
 * @bo: BO to clear
 * @level: level this BO is at
 * @pte_support_ats: indicate ATS support from PTE
 *
 * Root PD needs to be reserved when calling this.
 *
 * Returns:
 * 0 on success, errno otherwise.
 */
static int amdgpu_vm_clear_bo(struct amdgpu_device *adev,
                              struct amdgpu_vm *vm, struct amdgpu_bo *bo,
                              unsigned level, bool pte_support_ats)
{
        struct ttm_operation_ctx ctx = { true, false };
        struct dma_fence *fence = NULL;
        unsigned entries, ats_entries;
        struct amdgpu_ring *ring;
        struct amdgpu_job *job;
        uint64_t addr;
        int r;

        entries = amdgpu_bo_size(bo) / 8;

        if (pte_support_ats) {
                if (level == adev->vm_manager.root_level) {
                        ats_entries = amdgpu_vm_level_shift(adev, level);
                        ats_entries += AMDGPU_GPU_PAGE_SHIFT;
                        ats_entries = AMDGPU_GMC_HOLE_START >> ats_entries;
                        ats_entries = min(ats_entries, entries);
                        entries -= ats_entries;
                } else {
                        ats_entries = entries;
                        entries = 0;
                }
        } else {
                ats_entries = 0;
        }

        ring = container_of(vm->entity.rq->sched, struct amdgpu_ring, sched);

        r = reservation_object_reserve_shared(bo->tbo.resv);
        if (r)
                return r;

        r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
        if (r)
                goto error;

        r = amdgpu_ttm_alloc_gart(&bo->tbo);
        if (r)
                return r;

        r = amdgpu_job_alloc_with_ib(adev, 64, &job);
        if (r)
                goto error;

        addr = amdgpu_bo_gpu_offset(bo);
        if (ats_entries) {
                uint64_t ats_value;

                ats_value = AMDGPU_PTE_DEFAULT_ATC;
                if (level != AMDGPU_VM_PTB)
                        ats_value |= AMDGPU_PDE_PTE;

                amdgpu_vm_set_pte_pde(adev, &job->ibs[0], addr, 0,
                                      ats_entries, 0, ats_value);
                addr += ats_entries * 8;
        }

        if (entries)
                amdgpu_vm_set_pte_pde(adev, &job->ibs[0], addr, 0,
                                      entries, 0, 0);

        amdgpu_ring_pad_ib(ring, &job->ibs[0]);

        WARN_ON(job->ibs[0].length_dw > 64);
        r = amdgpu_sync_resv(adev, &job->sync, bo->tbo.resv,
                             AMDGPU_FENCE_OWNER_UNDEFINED, false);
        if (r)
                goto error_free;

        r = amdgpu_job_submit(job, &vm->entity, AMDGPU_FENCE_OWNER_UNDEFINED,
                              &fence);
        if (r)
                goto error_free;

        amdgpu_bo_fence(bo, fence, true);
        dma_fence_put(fence);

        if (bo->shadow)
                return amdgpu_vm_clear_bo(adev, vm, bo->shadow,
                                          level, pte_support_ats);

        return 0;

error_free:
        amdgpu_job_free(job);

error:
        return r;
}

/**
 * amdgpu_vm_bo_param - fill in parameters for PD/PT allocation
 *
 * @adev: amdgpu_device pointer
 * @vm: requesting vm
 * @bp: resulting BO allocation parameters
 */
static void amdgpu_vm_bo_param(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                               int level, struct amdgpu_bo_param *bp)
{
        memset(bp, 0, sizeof(*bp));

        bp->size = amdgpu_vm_bo_size(adev, level);
        bp->byte_align = AMDGPU_GPU_PAGE_SIZE;
        bp->domain = AMDGPU_GEM_DOMAIN_VRAM;
        bp->domain = amdgpu_bo_get_preferred_pin_domain(adev, bp->domain);
        bp->flags = AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS |
                AMDGPU_GEM_CREATE_CPU_GTT_USWC;
        if (vm->use_cpu_for_update)
                bp->flags |= AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
        else if (!vm->root.base.bo || vm->root.base.bo->shadow)
                bp->flags |= AMDGPU_GEM_CREATE_SHADOW;
        bp->type = ttm_bo_type_kernel;
        if (vm->root.base.bo)
                bp->resv = vm->root.base.bo->tbo.resv;
}

/**
 * amdgpu_vm_alloc_pts - Allocate page tables.
 *
 * @adev: amdgpu_device pointer
 * @vm: VM to allocate page tables for
 * @saddr: Start address which needs to be allocated
 * @size: Size from start address we need.
 *
 * Make sure the page directories and page tables are allocated
 *
 * Returns:
 * 0 on success, errno otherwise.
 */
int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
                        struct amdgpu_vm *vm,
                        uint64_t saddr, uint64_t size)
{
        struct amdgpu_vm_pt_cursor cursor;
        struct amdgpu_bo *pt;
        bool ats = false;
        uint64_t eaddr;
        int r;

        /* validate the parameters */
        if (saddr & AMDGPU_GPU_PAGE_MASK || size & AMDGPU_GPU_PAGE_MASK)
                return -EINVAL;

        eaddr = saddr + size - 1;

        if (vm->pte_support_ats)
                ats = saddr < AMDGPU_GMC_HOLE_START;

        saddr /= AMDGPU_GPU_PAGE_SIZE;
        eaddr /= AMDGPU_GPU_PAGE_SIZE;

        if (eaddr >= adev->vm_manager.max_pfn) {
                dev_err(adev->dev, "va above limit (0x%08lX >= 0x%08lX)\n",
                        eaddr, adev->vm_manager.max_pfn);
                return -EINVAL;
        }

        for_each_amdgpu_vm_pt_leaf(adev, vm, saddr, eaddr, cursor) {
                struct amdgpu_vm_pt *entry = cursor.entry;
                struct amdgpu_bo_param bp;

                if (cursor.level < AMDGPU_VM_PTB) {
                        unsigned num_entries;

                        num_entries = amdgpu_vm_num_entries(adev, cursor.level);
                        entry->entries = kvmalloc_array(num_entries,
                                                        sizeof(*entry->entries),
                                                        GFP_KERNEL |
                                                        __GFP_ZERO);
                        if (!entry->entries)
                                return -ENOMEM;
                }


                if (entry->base.bo)
                        continue;

                amdgpu_vm_bo_param(adev, vm, cursor.level, &bp);

                r = amdgpu_bo_create(adev, &bp, &pt);
                if (r)
                        return r;

                r = amdgpu_vm_clear_bo(adev, vm, pt, cursor.level, ats);
                if (r)
                        goto error_free_pt;

                if (vm->use_cpu_for_update) {
                        r = amdgpu_bo_kmap(pt, NULL);
                        if (r)
                                goto error_free_pt;
                }

                /* Keep a reference to the root directory to avoid
                * freeing them up in the wrong order.
                */
                pt->parent = amdgpu_bo_ref(cursor.parent->base.bo);

                amdgpu_vm_bo_base_init(&entry->base, vm, pt);
        }

        return 0;

error_free_pt:
        amdgpu_bo_unref(&pt->shadow);
        amdgpu_bo_unref(&pt);
        return r;
}

/**
 * amdgpu_vm_free_pts - free PD/PT levels
 *
 * @adev: amdgpu device structure
 * @vm: amdgpu vm structure
 *
 * Free the page directory or page table level and all sub levels.
 */
static void amdgpu_vm_free_pts(struct amdgpu_device *adev,
                               struct amdgpu_vm *vm)
{
        struct amdgpu_vm_pt_cursor cursor;
        struct amdgpu_vm_pt *entry;

        for_each_amdgpu_vm_pt_dfs_safe(adev, vm, cursor, entry) {

                if (entry->base.bo) {
                        entry->base.bo->vm_bo = NULL;
                        list_del(&entry->base.vm_status);
                        amdgpu_bo_unref(&entry->base.bo->shadow);
                        amdgpu_bo_unref(&entry->base.bo);
                }
                kvfree(entry->entries);
        }

        BUG_ON(vm->root.base.bo);
}

/**
 * amdgpu_vm_check_compute_bug - check whether asic has compute vm bug
 *
 * @adev: amdgpu_device pointer
 */
void amdgpu_vm_check_compute_bug(struct amdgpu_device *adev)
{
        const struct amdgpu_ip_block *ip_block;
        bool has_compute_vm_bug;
        struct amdgpu_ring *ring;
        int i;

        has_compute_vm_bug = false;

        ip_block = amdgpu_device_ip_get_ip_block(adev, AMD_IP_BLOCK_TYPE_GFX);
        if (ip_block) {
                /* Compute has a VM bug for GFX version < 7.
                   Compute has a VM bug for GFX 8 MEC firmware version < 673.*/
                if (ip_block->version->major <= 7)
                        has_compute_vm_bug = true;
                else if (ip_block->version->major == 8)
                        if (adev->gfx.mec_fw_version < 673)
                                has_compute_vm_bug = true;
        }

        for (i = 0; i < adev->num_rings; i++) {
                ring = adev->rings[i];
                if (ring->funcs->type == AMDGPU_RING_TYPE_COMPUTE)
                        /* only compute rings */
                        ring->has_compute_vm_bug = has_compute_vm_bug;
                else
                        ring->has_compute_vm_bug = false;
        }
}

/**
 * amdgpu_vm_need_pipeline_sync - Check if pipe sync is needed for job.
 *
 * @ring: ring on which the job will be submitted
 * @job: job to submit
 *
 * Returns:
 * True if sync is needed.
 */
bool amdgpu_vm_need_pipeline_sync(struct amdgpu_ring *ring,
                                  struct amdgpu_job *job)
{
        struct amdgpu_device *adev = ring->adev;
        unsigned vmhub = ring->funcs->vmhub;
        struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
        struct amdgpu_vmid *id;
        bool gds_switch_needed;
        bool vm_flush_needed = job->vm_needs_flush || ring->has_compute_vm_bug;

        if (job->vmid == 0)
                return false;
        id = &id_mgr->ids[job->vmid];
        gds_switch_needed = ring->funcs->emit_gds_switch && (
                id->gds_base != job->gds_base ||
                id->gds_size != job->gds_size ||
                id->gws_base != job->gws_base ||
                id->gws_size != job->gws_size ||
                id->oa_base != job->oa_base ||
                id->oa_size != job->oa_size);

        if (amdgpu_vmid_had_gpu_reset(adev, id))
                return true;

        return vm_flush_needed || gds_switch_needed;
}

/**
 * amdgpu_vm_flush - hardware flush the vm
 *
 * @ring: ring to use for flush
 * @job:  related job
 * @need_pipe_sync: is pipe sync needed
 *
 * Emit a VM flush when it is necessary.
 *
 * Returns:
 * 0 on success, errno otherwise.
 */
int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job, bool need_pipe_sync)
{
        struct amdgpu_device *adev = ring->adev;
        unsigned vmhub = ring->funcs->vmhub;
        struct amdgpu_vmid_mgr *id_mgr = &adev->vm_manager.id_mgr[vmhub];
        struct amdgpu_vmid *id = &id_mgr->ids[job->vmid];
        bool gds_switch_needed = ring->funcs->emit_gds_switch && (
                id->gds_base != job->gds_base ||
                id->gds_size != job->gds_size ||
                id->gws_base != job->gws_base ||
                id->gws_size != job->gws_size ||
                id->oa_base != job->oa_base ||
                id->oa_size != job->oa_size);
        bool vm_flush_needed = job->vm_needs_flush;
        bool pasid_mapping_needed = id->pasid != job->pasid ||
                !id->pasid_mapping ||
                !dma_fence_is_signaled(id->pasid_mapping);
        struct dma_fence *fence = NULL;
        unsigned patch_offset = 0;
        int r;

        if (amdgpu_vmid_had_gpu_reset(adev, id)) {
                gds_switch_needed = true;
                vm_flush_needed = true;
                pasid_mapping_needed = true;
        }

        gds_switch_needed &= !!ring->funcs->emit_gds_switch;
        vm_flush_needed &= !!ring->funcs->emit_vm_flush  &&
                        job->vm_pd_addr != AMDGPU_BO_INVALID_OFFSET;
        pasid_mapping_needed &= adev->gmc.gmc_funcs->emit_pasid_mapping &&
                ring->funcs->emit_wreg;

        if (!vm_flush_needed && !gds_switch_needed && !need_pipe_sync)
                return 0;

        if (ring->funcs->init_cond_exec)
                patch_offset = amdgpu_ring_init_cond_exec(ring);

        if (need_pipe_sync)
                amdgpu_ring_emit_pipeline_sync(ring);

        if (vm_flush_needed) {
                trace_amdgpu_vm_flush(ring, job->vmid, job->vm_pd_addr);
                amdgpu_ring_emit_vm_flush(ring, job->vmid, job->vm_pd_addr);
        }

        if (pasid_mapping_needed)
                amdgpu_gmc_emit_pasid_mapping(ring, job->vmid, job->pasid);

        if (vm_flush_needed || pasid_mapping_needed) {
                r = amdgpu_fence_emit(ring, &fence, 0);
                if (r)
                        return r;
        }

        if (vm_flush_needed) {
                mutex_lock(&id_mgr->lock);
                dma_fence_put(id->last_flush);
                id->last_flush = dma_fence_get(fence);
                id->current_gpu_reset_count =
                        atomic_read(&adev->gpu_reset_counter);
                mutex_unlock(&id_mgr->lock);
        }

        if (pasid_mapping_needed) {
                id->pasid = job->pasid;
                dma_fence_put(id->pasid_mapping);
                id->pasid_mapping = dma_fence_get(fence);
        }
        dma_fence_put(fence);

        if (ring->funcs->emit_gds_switch && gds_switch_needed) {
                id->gds_base = job->gds_base;
                id->gds_size = job->gds_size;
                id->gws_base = job->gws_base;
                id->gws_size = job->gws_size;
                id->oa_base = job->oa_base;
                id->oa_size = job->oa_size;
                amdgpu_ring_emit_gds_switch(ring, job->vmid, job->gds_base,
                                            job->gds_size, job->gws_base,
                                            job->gws_size, job->oa_base,
                                            job->oa_size);
        }

        if (ring->funcs->patch_cond_exec)
                amdgpu_ring_patch_cond_exec(ring, patch_offset);

        /* the double SWITCH_BUFFER here *cannot* be skipped by COND_EXEC */
        if (ring->funcs->emit_switch_buffer) {
                amdgpu_ring_emit_switch_buffer(ring);
                amdgpu_ring_emit_switch_buffer(ring);
        }
        return 0;
}

/**
 * amdgpu_vm_bo_find - find the bo_va for a specific vm & bo
 *
 * @vm: requested vm
 * @bo: requested buffer object
 *
 * Find @bo inside the requested vm.
 * Search inside the @bos vm list for the requested vm
 * Returns the found bo_va or NULL if none is found
 *
 * Object has to be reserved!
 *
 * Returns:
 * Found bo_va or NULL.
 */
struct amdgpu_bo_va *amdgpu_vm_bo_find(struct amdgpu_vm *vm,
                                       struct amdgpu_bo *bo)
{
        struct amdgpu_vm_bo_base *base;

        for (base = bo->vm_bo; base; base = base->next) {
                if (base->vm != vm)
                        continue;

                return container_of(base, struct amdgpu_bo_va, base);
        }
        return NULL;
}

/**
 * amdgpu_vm_do_set_ptes - helper to call the right asic function
 *
 * @params: see amdgpu_pte_update_params definition
 * @bo: PD/PT to update
 * @pe: addr of the page entry
 * @addr: dst addr to write into pe
 * @count: number of page entries to update
 * @incr: increase next addr by incr bytes
 * @flags: hw access flags
 *
 * Traces the parameters and calls the right asic functions
 * to setup the page table using the DMA.
 */
static void amdgpu_vm_do_set_ptes(struct amdgpu_pte_update_params *params,
                                  struct amdgpu_bo *bo,
                                  uint64_t pe, uint64_t addr,
                                  unsigned count, uint32_t incr,
                                  uint64_t flags)
{
        pe += amdgpu_bo_gpu_offset(bo);
        trace_amdgpu_vm_set_ptes(pe, addr, count, incr, flags);

        if (count < 3) {
                amdgpu_vm_write_pte(params->adev, params->ib, pe,
                                    addr | flags, count, incr);

        } else {
                amdgpu_vm_set_pte_pde(params->adev, params->ib, pe, addr,
                                      count, incr, flags);
        }
}

/**
 * amdgpu_vm_do_copy_ptes - copy the PTEs from the GART
 *
 * @params: see amdgpu_pte_update_params definition
 * @bo: PD/PT to update
 * @pe: addr of the page entry
 * @addr: dst addr to write into pe
 * @count: number of page entries to update
 * @incr: increase next addr by incr bytes
 * @flags: hw access flags
 *
 * Traces the parameters and calls the DMA function to copy the PTEs.
 */
static void amdgpu_vm_do_copy_ptes(struct amdgpu_pte_update_params *params,
                                   struct amdgpu_bo *bo,
                                   uint64_t pe, uint64_t addr,
                                   unsigned count, uint32_t incr,
                                   uint64_t flags)
{
        uint64_t src = (params->src + (addr >> 12) * 8);

        pe += amdgpu_bo_gpu_offset(bo);
        trace_amdgpu_vm_copy_ptes(pe, src, count);

        amdgpu_vm_copy_pte(params->adev, params->ib, pe, src, count);
}

/**
 * amdgpu_vm_map_gart - Resolve gart mapping of addr
 *
 * @pages_addr: optional DMA address to use for lookup
 * @addr: the unmapped addr
 *
 * Look up the physical address of the page that the pte resolves
 * to.
 *
 * Returns:
 * The pointer for the page table entry.
 */
static uint64_t amdgpu_vm_map_gart(const dma_addr_t *pages_addr, uint64_t addr)
{
        uint64_t result;

        /* page table offset */
        result = pages_addr[addr >> PAGE_SHIFT];

        /* in case cpu page size != gpu page size*/
        result |= addr & (~PAGE_MASK);

        result &= 0xFFFFFFFFFFFFF000ULL;

        return result;
}

/**
 * amdgpu_vm_cpu_set_ptes - helper to update page tables via CPU
 *
 * @params: see amdgpu_pte_update_params definition
 * @bo: PD/PT to update
 * @pe: kmap addr of the page entry
 * @addr: dst addr to write into pe
 * @count: number of page entries to update
 * @incr: increase next addr by incr bytes
 * @flags: hw access flags
 *
 * Write count number of PT/PD entries directly.
 */
static void amdgpu_vm_cpu_set_ptes(struct amdgpu_pte_update_params *params,
                                   struct amdgpu_bo *bo,
                                   uint64_t pe, uint64_t addr,
                                   unsigned count, uint32_t incr,
                                   uint64_t flags)
{
        unsigned int i;
        uint64_t value;

        pe += (unsigned long)amdgpu_bo_kptr(bo);

        trace_amdgpu_vm_set_ptes(pe, addr, count, incr, flags);

        for (i = 0; i < count; i++) {
                value = params->pages_addr ?
                        amdgpu_vm_map_gart(params->pages_addr, addr) :
                        addr;
                amdgpu_gmc_set_pte_pde(params->adev, (void *)(uintptr_t)pe,
                                       i, value, flags);
                addr += incr;
        }
}


/**
 * amdgpu_vm_wait_pd - Wait for PT BOs to be free.
 *
 * @adev: amdgpu_device pointer
 * @vm: related vm
 * @owner: fence owner
 *
 * Returns:
 * 0 on success, errno otherwise.
 */
static int amdgpu_vm_wait_pd(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                             void *owner)
{
        struct amdgpu_sync sync;
        int r;

        amdgpu_sync_create(&sync);
        amdgpu_sync_resv(adev, &sync, vm->root.base.bo->tbo.resv, owner, false);
        r = amdgpu_sync_wait(&sync, true);
        amdgpu_sync_free(&sync);

        return r;
}

/**
 * amdgpu_vm_update_func - helper to call update function
 *
 * Calls the update function for both the given BO as well as its shadow.
 */
static void amdgpu_vm_update_func(struct amdgpu_pte_update_params *params,
                                  struct amdgpu_bo *bo,
                                  uint64_t pe, uint64_t addr,
                                  unsigned count, uint32_t incr,
                                  uint64_t flags)
{
        if (bo->shadow)
                params->func(params, bo->shadow, pe, addr, count, incr, flags);
        params->func(params, bo, pe, addr, count, incr, flags);
}

/*
 * amdgpu_vm_update_pde - update a single level in the hierarchy
 *
 * @param: parameters for the update
 * @vm: requested vm
 * @parent: parent directory
 * @entry: entry to update
 *
 * Makes sure the requested entry in parent is up to date.
 */
static void amdgpu_vm_update_pde(struct amdgpu_pte_update_params *params,
                                 struct amdgpu_vm *vm,
                                 struct amdgpu_vm_pt *parent,
                                 struct amdgpu_vm_pt *entry)
{
        struct amdgpu_bo *bo = parent->base.bo, *pbo;
        uint64_t pde, pt, flags;
        unsigned level;

        /* Don't update huge pages here */
        if (entry->huge)
                return;

        for (level = 0, pbo = bo->parent; pbo; ++level)
                pbo = pbo->parent;

        level += params->adev->vm_manager.root_level;
        amdgpu_gmc_get_pde_for_bo(entry->base.bo, level, &pt, &flags);
        pde = (entry - parent->entries) * 8;
        amdgpu_vm_update_func(params, bo, pde, pt, 1, 0, flags);
}

/*
 * amdgpu_vm_invalidate_pds - mark all PDs as invalid
 *
 * @adev: amdgpu_device pointer
 * @vm: related vm
 *
 * Mark all PD level as invalid after an error.
 */
static void amdgpu_vm_invalidate_pds(struct amdgpu_device *adev,
                                     struct amdgpu_vm *vm)
{
        struct amdgpu_vm_pt_cursor cursor;
        struct amdgpu_vm_pt *entry;

        for_each_amdgpu_vm_pt_dfs_safe(adev, vm, cursor, entry)
                if (entry->base.bo && !entry->base.moved)
                        amdgpu_vm_bo_relocated(&entry->base);
}

/*
 * amdgpu_vm_update_directories - make sure that all directories are valid
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * Makes sure all directories are up to date.
 *
 * Returns:
 * 0 for success, error for failure.
 */
int amdgpu_vm_update_directories(struct amdgpu_device *adev,
                                 struct amdgpu_vm *vm)
{
        struct amdgpu_pte_update_params params;
        struct amdgpu_job *job;
        unsigned ndw = 0;
        int r = 0;

        if (list_empty(&vm->relocated))
                return 0;

restart:
        memset(&params, 0, sizeof(params));
        params.adev = adev;

        if (vm->use_cpu_for_update) {
                r = amdgpu_vm_wait_pd(adev, vm, AMDGPU_FENCE_OWNER_VM);
                if (unlikely(r))
                        return r;

                params.func = amdgpu_vm_cpu_set_ptes;
        } else {
                ndw = 512 * 8;
                r = amdgpu_job_alloc_with_ib(adev, ndw * 4, &job);
                if (r)
                        return r;

                params.ib = &job->ibs[0];
                params.func = amdgpu_vm_do_set_ptes;
        }

        while (!list_empty(&vm->relocated)) {
                struct amdgpu_vm_pt *pt, *entry;

                entry = list_first_entry(&vm->relocated, struct amdgpu_vm_pt,
                                         base.vm_status);
                amdgpu_vm_bo_idle(&entry->base);

                pt = amdgpu_vm_pt_parent(entry);
                if (!pt)
                        continue;

                amdgpu_vm_update_pde(&params, vm, pt, entry);

                if (!vm->use_cpu_for_update &&
                    (ndw - params.ib->length_dw) < 32)
                        break;
        }

        if (vm->use_cpu_for_update) {
                /* Flush HDP */
                mb();
                amdgpu_asic_flush_hdp(adev, NULL);
        } else if (params.ib->length_dw == 0) {
                amdgpu_job_free(job);
        } else {
                struct amdgpu_bo *root = vm->root.base.bo;
                struct amdgpu_ring *ring;
                struct dma_fence *fence;

                ring = container_of(vm->entity.rq->sched, struct amdgpu_ring,
                                    sched);

                amdgpu_ring_pad_ib(ring, params.ib);
                amdgpu_sync_resv(adev, &job->sync, root->tbo.resv,
                                 AMDGPU_FENCE_OWNER_VM, false);
                WARN_ON(params.ib->length_dw > ndw);
                r = amdgpu_job_submit(job, &vm->entity, AMDGPU_FENCE_OWNER_VM,
                                      &fence);
                if (r)
                        goto error;

                amdgpu_bo_fence(root, fence, true);
                dma_fence_put(vm->last_update);
                vm->last_update = fence;
        }

        if (!list_empty(&vm->relocated))
                goto restart;

        return 0;

error:
        amdgpu_vm_invalidate_pds(adev, vm);
        amdgpu_job_free(job);
        return r;
}

/**
 * amdgpu_vm_update_huge - figure out parameters for PTE updates
 *
 * Make sure to set the right flags for the PTEs at the desired level.
 */
static void amdgpu_vm_update_huge(struct amdgpu_pte_update_params *params,
                                  struct amdgpu_bo *bo, unsigned level,
                                  uint64_t pe, uint64_t addr,
                                  unsigned count, uint32_t incr,
                                  uint64_t flags)

{
        if (level != AMDGPU_VM_PTB) {
                flags |= AMDGPU_PDE_PTE;
                amdgpu_gmc_get_vm_pde(params->adev, level, (u64)&addr, (u64)&flags);
        }

        amdgpu_vm_update_func(params, bo, pe, addr, count, incr, flags);
}

/**
 * amdgpu_vm_fragment - get fragment for PTEs
 *
 * @params: see amdgpu_pte_update_params definition
 * @start: first PTE to handle
 * @end: last PTE to handle
 * @flags: hw mapping flags
 * @frag: resulting fragment size
 * @frag_end: end of this fragment
 *
 * Returns the first possible fragment for the start and end address.
 */
static void amdgpu_vm_fragment(struct amdgpu_pte_update_params *params,
                               uint64_t start, uint64_t end, uint64_t flags,
                               unsigned int *frag, uint64_t *frag_end)
{
        /**
         * The MC L1 TLB supports variable sized pages, based on a fragment
         * field in the PTE. When this field is set to a non-zero value, page
         * granularity is increased from 4KB to (1 << (12 + frag)). The PTE
         * flags are considered valid for all PTEs within the fragment range
         * and corresponding mappings are assumed to be physically contiguous.
         *
         * The L1 TLB can store a single PTE for the whole fragment,
         * significantly increasing the space available for translation
         * caching. This leads to large improvements in throughput when the
         * TLB is under pressure.
         *
         * The L2 TLB distributes small and large fragments into two
         * asymmetric partitions. The large fragment cache is significantly
         * larger. Thus, we try to use large fragments wherever possible.
         * Userspace can support this by aligning virtual base address and
         * allocation size to the fragment size.
         *
         * Starting with Vega10 the fragment size only controls the L1. The L2
         * is now directly feed with small/huge/giant pages from the walker.
         */
        unsigned max_frag;

        if (params->adev->asic_type < CHIP_VEGA10)
                max_frag = params->adev->vm_manager.fragment_size;
        else
                max_frag = 31;

        /* system pages are non continuously */
        if (params->src) {
                *frag = 0;
                *frag_end = end;
                return;
        }

        /* This intentionally wraps around if no bit is set */
        *frag = min((unsigned)ffs(start) - 1, (unsigned)fls64(end - start) - 1);
        if (*frag >= max_frag) {
                *frag = max_frag;
                *frag_end = end & ~((1ULL << max_frag) - 1);
        } else {
                *frag_end = start + (1 << *frag);
        }
}

/**
 * amdgpu_vm_update_ptes - make sure that page tables are valid
 *
 * @params: see amdgpu_pte_update_params definition
 * @start: start of GPU address range
 * @end: end of GPU address range
 * @dst: destination address to map to, the next dst inside the function
 * @flags: mapping flags
 *
 * Update the page tables in the range @start - @end.
 *
 * Returns:
 * 0 for success, -EINVAL for failure.
 */
static int amdgpu_vm_update_ptes(struct amdgpu_pte_update_params *params,
                                 uint64_t start, uint64_t end,
                                 uint64_t dst, uint64_t flags)
{
        struct amdgpu_device *adev = params->adev;
        struct amdgpu_vm_pt_cursor cursor;
        uint64_t frag_start = start, frag_end;
        unsigned int frag;

        /* figure out the initial fragment */
        amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);

        /* walk over the address space and update the PTs */
        amdgpu_vm_pt_start(adev, params->vm, start, &cursor);
        while (cursor.pfn < end) {
                struct amdgpu_bo *pt = cursor.entry->base.bo;
                unsigned shift, parent_shift, mask;
                uint64_t incr, entry_end, pe_start;

                if (!pt)
                        return -ENOENT;

                /* The root level can't be a huge page */
                if (cursor.level == adev->vm_manager.root_level) {
                        if (!amdgpu_vm_pt_descendant(adev, &cursor))
                                return -ENOENT;
                        continue;
                }

                /* If it isn't already handled it can't be a huge page */
                if (cursor.entry->huge) {
                        /* Add the entry to the relocated list to update it. */
                        cursor.entry->huge = false;
                        amdgpu_vm_bo_relocated(&cursor.entry->base);
                }

                shift = amdgpu_vm_level_shift(adev, cursor.level);
                parent_shift = amdgpu_vm_level_shift(adev, cursor.level - 1);
                if (adev->asic_type < CHIP_VEGA10) {
                        /* No huge page support before GMC v9 */
                        if (cursor.level != AMDGPU_VM_PTB) {
                                if (!amdgpu_vm_pt_descendant(adev, &cursor))
                                        return -ENOENT;
                                continue;
                        }
                } else if (frag < shift) {
                        /* We can't use this level when the fragment size is
                         * smaller than the address shift. Go to the next
                         * child entry and try again.
                         */
                        if (!amdgpu_vm_pt_descendant(adev, &cursor))
                                return -ENOENT;
                        continue;
                } else if (frag >= parent_shift &&
                           cursor.level - 1 != adev->vm_manager.root_level) {
                        /* If the fragment size is even larger than the parent
                         * shift we should go up one level and check it again
                         * unless one level up is the root level.
                         */
                        if (!amdgpu_vm_pt_ancestor(&cursor))
                                return -ENOENT;
                        continue;
                }

                /* Looks good so far, calculate parameters for the update */
                incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
                mask = amdgpu_vm_entries_mask(adev, cursor.level);
                pe_start = ((cursor.pfn >> shift) & mask) * 8;
                entry_end = (uint64_t)(mask + 1) << shift;
                entry_end += cursor.pfn & ~(entry_end - 1);
                entry_end = min(entry_end, end);

                do {
                        uint64_t upd_end = min(entry_end, frag_end);
                        unsigned nptes = (upd_end - frag_start) >> shift;

                        amdgpu_vm_update_huge(params, pt, cursor.level,
                                              pe_start, dst, nptes, incr,
                                              flags | AMDGPU_PTE_FRAG(frag));

                        pe_start += nptes * 8;
                        dst += (uint64_t)nptes * AMDGPU_GPU_PAGE_SIZE << shift;

                        frag_start = upd_end;
                        if (frag_start >= frag_end) {
                                /* figure out the next fragment */
                                amdgpu_vm_fragment(params, frag_start, end,
                                                   flags, &frag, &frag_end);
                                if (frag < shift)
                                        break;
                        }
                } while (frag_start < entry_end);

                if (amdgpu_vm_pt_descendant(adev, &cursor)) {
                        /* Mark all child entries as huge */
                        while (cursor.pfn < frag_start) {
                                cursor.entry->huge = true;
                                amdgpu_vm_pt_next(adev, &cursor);
                        }

                } else if (frag >= shift) {
                        /* or just move on to the next on the same level. */
                        amdgpu_vm_pt_next(adev, &cursor);
                }
        }

        return 0;
}

/**
 * amdgpu_vm_bo_update_mapping - update a mapping in the vm page table
 *
 * @adev: amdgpu_device pointer
 * @exclusive: fence we need to sync to
 * @pages_addr: DMA addresses to use for mapping
 * @vm: requested vm
 * @start: start of mapped range
 * @last: last mapped entry
 * @flags: flags for the entries
 * @addr: addr to set the area to
 * @fence: optional resulting fence
 *
 * Fill in the page table entries between @start and @last.
 *
 * Returns:
 * 0 for success, -EINVAL for failure.
 */
static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
                                       struct dma_fence *exclusive,
                                       dma_addr_t *pages_addr,
                                       struct amdgpu_vm *vm,
                                       uint64_t start, uint64_t last,
                                       uint64_t flags, uint64_t addr,
                                       struct dma_fence **fence)
{
        struct amdgpu_ring *ring;
        void *owner = AMDGPU_FENCE_OWNER_VM;
        unsigned nptes, ncmds, ndw;
        struct amdgpu_job *job;
        struct amdgpu_pte_update_params params;
        struct dma_fence *f = NULL;
        int r;

        memset(&params, 0, sizeof(params));
        params.adev = adev;
        params.vm = vm;

        /* sync to everything on unmapping */
        if (!(flags & AMDGPU_PTE_VALID))
                owner = AMDGPU_FENCE_OWNER_UNDEFINED;

        if (vm->use_cpu_for_update) {
                /* params.src is used as flag to indicate system Memory */
                if (pages_addr)
                        params.src = ~0;

                /* Wait for PT BOs to be free. PTs share the same resv. object
                 * as the root PD BO
                 */
                r = amdgpu_vm_wait_pd(adev, vm, owner);
                if (unlikely(r))
                        return r;

                params.func = amdgpu_vm_cpu_set_ptes;
                params.pages_addr = pages_addr;
                return amdgpu_vm_update_ptes(&params, start, last + 1,
                                             addr, flags);
        }

        ring = container_of(vm->entity.rq->sched, struct amdgpu_ring, sched);

        nptes = last - start + 1;

        /*
         * reserve space for two commands every (1 << BLOCK_SIZE)
         *  entries or 2k dwords (whatever is smaller)
         *
         * The second command is for the shadow pagetables.
         */
        if (vm->root.base.bo->shadow)
                ncmds = ((nptes >> min(adev->vm_manager.block_size, 11u)) + 1) * 2;
        else
                ncmds = ((nptes >> min(adev->vm_manager.block_size, 11u)) + 1);

        /* padding, etc. */
        ndw = 64;

        if (pages_addr) {
                /* copy commands needed */
                ndw += ncmds * adev->vm_manager.vm_pte_funcs->copy_pte_num_dw;

                /* and also PTEs */
                ndw += nptes * 2;

                params.func = amdgpu_vm_do_copy_ptes;

        } else {
                /* set page commands needed */
                ndw += ncmds * 10;

                /* extra commands for begin/end fragments */
                if (vm->root.base.bo->shadow)
                        ndw += 2 * 10 * adev->vm_manager.fragment_size * 2;
                else
                        ndw += 2 * 10 * adev->vm_manager.fragment_size;

                params.func = amdgpu_vm_do_set_ptes;
        }

        r = amdgpu_job_alloc_with_ib(adev, ndw * 4, &job);
        if (r)
                return r;

        params.ib = &job->ibs[0];

        if (pages_addr) {
                uint64_t *pte;
                unsigned i;

                /* Put the PTEs at the end of the IB. */
                i = ndw - nptes * 2;
                pte= (uint64_t *)&(job->ibs->ptr[i]);
                params.src = job->ibs->gpu_addr + i * 4;

                for (i = 0; i < nptes; ++i) {
                        pte[i] = amdgpu_vm_map_gart(pages_addr, addr + i *
                                                    AMDGPU_GPU_PAGE_SIZE);
                        pte[i] |= flags;
                }
                addr = 0;
        }

        r = amdgpu_sync_fence(adev, &job->sync, exclusive, false);
        if (r)
                goto error_free;

        r = amdgpu_sync_resv(adev, &job->sync, vm->root.base.bo->tbo.resv,
                             owner, false);
        if (r)
                goto error_free;

        r = reservation_object_reserve_shared(vm->root.base.bo->tbo.resv);
        if (r)
                goto error_free;

        r = amdgpu_vm_update_ptes(&params, start, last + 1, addr, flags);
        if (r)
                goto error_free;

        amdgpu_ring_pad_ib(ring, params.ib);
        WARN_ON(params.ib->length_dw > ndw);
        r = amdgpu_job_submit(job, &vm->entity, AMDGPU_FENCE_OWNER_VM, &f);
        if (r)
                goto error_free;

        amdgpu_bo_fence(vm->root.base.bo, f, true);
        dma_fence_put(*fence);
        *fence = f;
        return 0;

error_free:
        amdgpu_job_free(job);
        return r;
}

/**
 * amdgpu_vm_bo_split_mapping - split a mapping into smaller chunks
 *
 * @adev: amdgpu_device pointer
 * @exclusive: fence we need to sync to
 * @pages_addr: DMA addresses to use for mapping
 * @vm: requested vm
 * @mapping: mapped range and flags to use for the update
 * @flags: HW flags for the mapping
 * @nodes: array of drm_mm_nodes with the MC addresses
 * @fence: optional resulting fence
 *
 * Split the mapping into smaller chunks so that each update fits
 * into a SDMA IB.
 *
 * Returns:
 * 0 for success, -EINVAL for failure.
 */
static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
                                      struct dma_fence *exclusive,
                                      dma_addr_t *pages_addr,
                                      struct amdgpu_vm *vm,
                                      struct amdgpu_bo_va_mapping *mapping,
                                      uint64_t flags,
                                      struct drm_mm_node *nodes,
                                      struct dma_fence **fence)
{
        unsigned min_linear_pages = 1 << adev->vm_manager.fragment_size;
        uint64_t pfn, start = mapping->start;
        int r;

        /* normally,bo_va->flags only contians READABLE and WIRTEABLE bit go here
         * but in case of something, we filter the flags in first place
         */
        if (!(mapping->flags & AMDGPU_PTE_READABLE))
                flags &= ~AMDGPU_PTE_READABLE;
        if (!(mapping->flags & AMDGPU_PTE_WRITEABLE))
                flags &= ~AMDGPU_PTE_WRITEABLE;

        flags &= ~AMDGPU_PTE_EXECUTABLE;
        flags |= mapping->flags & AMDGPU_PTE_EXECUTABLE;

        flags &= ~AMDGPU_PTE_MTYPE_MASK;
        flags |= (mapping->flags & AMDGPU_PTE_MTYPE_MASK);

        if ((mapping->flags & AMDGPU_PTE_PRT) &&
            (adev->asic_type >= CHIP_VEGA10)) {
                flags |= AMDGPU_PTE_PRT;
                flags &= ~AMDGPU_PTE_VALID;
        }

        trace_amdgpu_vm_bo_update(mapping);

        pfn = mapping->offset >> PAGE_SHIFT;
        if (nodes) {
                while (pfn >= nodes->size) {
                        pfn -= nodes->size;
                        ++nodes;
                }
        }

        do {
                dma_addr_t *dma_addr = NULL;
                uint64_t max_entries;
                uint64_t addr, last;

                if (nodes) {
                        addr = nodes->start << PAGE_SHIFT;
                        max_entries = (nodes->size - pfn) *
                                AMDGPU_GPU_PAGES_IN_CPU_PAGE;
                } else {
                        addr = 0;
                        max_entries = S64_MAX;
                }

                if (pages_addr) {
                        uint64_t count;

                        max_entries = min(max_entries, 16ull * 1024ull);
                        for (count = 1;
                             count < max_entries / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
                             ++count) {
                                uint64_t idx = pfn + count;

                                if (pages_addr[idx] !=
                                    (pages_addr[idx - 1] + PAGE_SIZE))
                                        break;
                        }

                        if (count < min_linear_pages) {
                                addr = pfn << PAGE_SHIFT;
                                dma_addr = pages_addr;
                        } else {
                                addr = pages_addr[pfn];
                                max_entries = count * AMDGPU_GPU_PAGES_IN_CPU_PAGE;
                        }

                } else if (flags & AMDGPU_PTE_VALID) {
                        addr += adev->vm_manager.vram_base_offset;
                        addr += pfn << PAGE_SHIFT;
                }

                last = min((uint64_t)mapping->last, start + max_entries - 1);
                r = amdgpu_vm_bo_update_mapping(adev, exclusive, dma_addr, vm,
                                                start, last, flags, addr,
                                                fence);
                if (r)
                        return r;

                pfn += (last - start + 1) / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
                if (nodes && nodes->size == pfn) {
                        pfn = 0;
                        ++nodes;
                }
                start = last + 1;

        } while (unlikely(start != mapping->last + 1));

        return 0;
}

/**
 * amdgpu_vm_bo_update - update all BO mappings in the vm page table
 *
 * @adev: amdgpu_device pointer
 * @bo_va: requested BO and VM object
 * @clear: if true clear the entries
 *
 * Fill in the page table entries for @bo_va.
 *
 * Returns:
 * 0 for success, -EINVAL for failure.
 */
int amdgpu_vm_bo_update(struct amdgpu_device *adev,
                        struct amdgpu_bo_va *bo_va,
                        bool clear)
{
        struct amdgpu_bo *bo = bo_va->base.bo;
        struct amdgpu_vm *vm = bo_va->base.vm;
        struct amdgpu_bo_va_mapping *mapping;
        dma_addr_t *pages_addr = NULL;
        struct ttm_mem_reg *mem;
        struct drm_mm_node *nodes;
        struct dma_fence *exclusive, **last_update;
        uint64_t flags;
        int r;

        if (clear || !bo) {
                mem = NULL;
                nodes = NULL;
                exclusive = NULL;
        } else {
                struct ttm_dma_tt *ttm;

                mem = &bo->tbo.mem;
                nodes = mem->mm_node;
                if (mem->mem_type == TTM_PL_TT) {
                        ttm = container_of(bo->tbo.ttm, struct ttm_dma_tt, ttm);
                        pages_addr = ttm->dma_address;
                }
                exclusive = reservation_object_get_excl(bo->tbo.resv);
        }

        if (bo)
                flags = amdgpu_ttm_tt_pte_flags(adev, bo->tbo.ttm, mem);
        else
                flags = 0x0;

        if (clear || (bo && bo->tbo.resv == vm->root.base.bo->tbo.resv))
                last_update = &vm->last_update;
        else
                last_update = &bo_va->last_pt_update;

        if (!clear && bo_va->base.moved) {
                bo_va->base.moved = false;
                list_splice_init(&bo_va->valids, &bo_va->invalids);

        } else if (bo_va->cleared != clear) {
                list_splice_init(&bo_va->valids, &bo_va->invalids);
        }

        list_for_each_entry(mapping, &bo_va->invalids, list) {
                r = amdgpu_vm_bo_split_mapping(adev, exclusive, pages_addr, vm,
                                               mapping, flags, nodes,
                                               last_update);
                if (r)
                        return r;
        }

        if (vm->use_cpu_for_update) {
                /* Flush HDP */
                mb();
                amdgpu_asic_flush_hdp(adev, NULL);
        }

        /* If the BO is not in its preferred location add it back to
         * the evicted list so that it gets validated again on the
         * next command submission.
         */
        if (bo && bo->tbo.resv == vm->root.base.bo->tbo.resv) {
                uint32_t mem_type = bo->tbo.mem.mem_type;

                if (!(bo->preferred_domains & amdgpu_mem_type_to_domain(mem_type)))
                        amdgpu_vm_bo_evicted(&bo_va->base);
                else
                        amdgpu_vm_bo_idle(&bo_va->base);
        } else {
                amdgpu_vm_bo_done(&bo_va->base);
        }

        list_splice_init(&bo_va->invalids, &bo_va->valids);
        bo_va->cleared = clear;

#if 0
        if (trace_amdgpu_vm_bo_mapping_enabled()) {
                list_for_each_entry(mapping, &bo_va->valids, list)
                        trace_amdgpu_vm_bo_mapping(mapping);
        }
#endif

        return 0;
}

/**
 * amdgpu_vm_update_prt_state - update the global PRT state
 *
 * @adev: amdgpu_device pointer
 */
static void amdgpu_vm_update_prt_state(struct amdgpu_device *adev)
{
        unsigned long flags;
        bool enable;

        spin_lock_irqsave(&adev->vm_manager.prt_lock, flags);
        enable = !!atomic_read(&adev->vm_manager.num_prt_users);
        adev->gmc.gmc_funcs->set_prt(adev, enable);
        spin_unlock_irqrestore(&adev->vm_manager.prt_lock, flags);
}

/**
 * amdgpu_vm_prt_get - add a PRT user
 *
 * @adev: amdgpu_device pointer
 */
static void amdgpu_vm_prt_get(struct amdgpu_device *adev)
{
        if (!adev->gmc.gmc_funcs->set_prt)
                return;

        if (atomic_inc_return(&adev->vm_manager.num_prt_users) == 1)
                amdgpu_vm_update_prt_state(adev);
}

/**
 * amdgpu_vm_prt_put - drop a PRT user
 *
 * @adev: amdgpu_device pointer
 */
static void amdgpu_vm_prt_put(struct amdgpu_device *adev)
{
        if (atomic_dec_return(&adev->vm_manager.num_prt_users) == 0)
                amdgpu_vm_update_prt_state(adev);
}

/**
 * amdgpu_vm_prt_cb - callback for updating the PRT status
 *
 * @fence: fence for the callback
 * @_cb: the callback function
 */
static void amdgpu_vm_prt_cb(struct dma_fence *fence, struct dma_fence_cb *_cb)
{
        struct amdgpu_prt_cb *cb = container_of(_cb, struct amdgpu_prt_cb, cb);

        amdgpu_vm_prt_put(cb->adev);
        kfree(cb);
}

/**
 * amdgpu_vm_add_prt_cb - add callback for updating the PRT status
 *
 * @adev: amdgpu_device pointer
 * @fence: fence for the callback
 */
static void amdgpu_vm_add_prt_cb(struct amdgpu_device *adev,
                                 struct dma_fence *fence)
{
        struct amdgpu_prt_cb *cb;

        if (!adev->gmc.gmc_funcs->set_prt)
                return;

        cb = kmalloc(sizeof(struct amdgpu_prt_cb), M_DRM, GFP_KERNEL);
        if (!cb) {
                /* Last resort when we are OOM */
                if (fence)
                        dma_fence_wait(fence, false);

                amdgpu_vm_prt_put(adev);
        } else {
                cb->adev = adev;
                if (!fence || dma_fence_add_callback(fence, &cb->cb,
                                                     amdgpu_vm_prt_cb))
                        amdgpu_vm_prt_cb(fence, &cb->cb);
        }
}

/**
 * amdgpu_vm_free_mapping - free a mapping
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 * @mapping: mapping to be freed
 * @fence: fence of the unmap operation
 *
 * Free a mapping and make sure we decrease the PRT usage count if applicable.
 */
static void amdgpu_vm_free_mapping(struct amdgpu_device *adev,
                                   struct amdgpu_vm *vm,
                                   struct amdgpu_bo_va_mapping *mapping,
                                   struct dma_fence *fence)
{
        if (mapping->flags & AMDGPU_PTE_PRT)
                amdgpu_vm_add_prt_cb(adev, fence);
        kfree(mapping);
}

/**
 * amdgpu_vm_prt_fini - finish all prt mappings
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * Register a cleanup callback to disable PRT support after VM dies.
 */
static void amdgpu_vm_prt_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
{
        struct reservation_object *resv = vm->root.base.bo->tbo.resv;
        struct dma_fence *excl, **shared;
        unsigned i, shared_count;
        int r;

        r = reservation_object_get_fences_rcu(resv, &excl,
                                              &shared_count, &shared);
        if (r) {
                /* Not enough memory to grab the fence list, as last resort
                 * block for all the fences to complete.
                 */
                reservation_object_wait_timeout_rcu(resv, true, false,
                                                    MAX_SCHEDULE_TIMEOUT);
                return;
        }

        /* Add a callback for each fence in the reservation object */
        amdgpu_vm_prt_get(adev);
        amdgpu_vm_add_prt_cb(adev, excl);

        for (i = 0; i < shared_count; ++i) {
                amdgpu_vm_prt_get(adev);
                amdgpu_vm_add_prt_cb(adev, shared[i]);
        }

        kfree(shared);
}

/**
 * amdgpu_vm_clear_freed - clear freed BOs in the PT
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 * @fence: optional resulting fence (unchanged if no work needed to be done
 * or if an error occurred)
 *
 * Make sure all freed BOs are cleared in the PT.
 * PTs have to be reserved and mutex must be locked!
 *
 * Returns:
 * 0 for success.
 *
 */
int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
                          struct amdgpu_vm *vm,
                          struct dma_fence **fence)
{
        struct amdgpu_bo_va_mapping *mapping;
        uint64_t init_pte_value = 0;
        struct dma_fence *f = NULL;
        int r;

        while (!list_empty(&vm->freed)) {
                mapping = list_first_entry(&vm->freed,
                        struct amdgpu_bo_va_mapping, list);
                list_del(&mapping->list);

                if (vm->pte_support_ats &&
                    mapping->start < AMDGPU_GMC_HOLE_START)
                        init_pte_value = AMDGPU_PTE_DEFAULT_ATC;

                r = amdgpu_vm_bo_update_mapping(adev, NULL, NULL, vm,
                                                mapping->start, mapping->last,
                                                init_pte_value, 0, &f);
                amdgpu_vm_free_mapping(adev, vm, mapping, f);
                if (r) {
                        dma_fence_put(f);
                        return r;
                }
        }

        if (fence && f) {
                dma_fence_put(*fence);
                *fence = f;
        } else {
                dma_fence_put(f);
        }

        return 0;

}

/**
 * amdgpu_vm_handle_moved - handle moved BOs in the PT
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * Make sure all BOs which are moved are updated in the PTs.
 *
 * Returns:
 * 0 for success.
 *
 * PTs have to be reserved!
 */
int amdgpu_vm_handle_moved(struct amdgpu_device *adev,
                           struct amdgpu_vm *vm)
{
        struct amdgpu_bo_va *bo_va, *tmp;
        struct reservation_object *resv;
        bool clear;
        int r;

        list_for_each_entry_safe(bo_va, tmp, &vm->moved, base.vm_status) {
                /* Per VM BOs never need to bo cleared in the page tables */
                r = amdgpu_vm_bo_update(adev, bo_va, false);
                if (r)
                        return r;
        }

        lockmgr(&vm->invalidated_lock, LK_EXCLUSIVE);
        while (!list_empty(&vm->invalidated)) {
                bo_va = list_first_entry(&vm->invalidated, struct amdgpu_bo_va,
                                         base.vm_status);
                resv = bo_va->base.bo->tbo.resv;
                lockmgr(&vm->invalidated_lock, LK_RELEASE);

                /* Try to reserve the BO to avoid clearing its ptes */
                if (!amdgpu_vm_debug && reservation_object_trylock(resv))
                        clear = false;
                /* Somebody else is using the BO right now */
                else
                        clear = true;

                r = amdgpu_vm_bo_update(adev, bo_va, clear);
                if (r)
                        return r;

                if (!clear)
                        reservation_object_unlock(resv);
                lockmgr(&vm->invalidated_lock, LK_EXCLUSIVE);
        }
        lockmgr(&vm->invalidated_lock, LK_RELEASE);

        return 0;
}

/**
 * amdgpu_vm_bo_add - add a bo to a specific vm
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 * @bo: amdgpu buffer object
 *
 * Add @bo into the requested vm.
 * Add @bo to the list of bos associated with the vm
 *
 * Returns:
 * Newly added bo_va or NULL for failure
 *
 * Object has to be reserved!
 */
struct amdgpu_bo_va *amdgpu_vm_bo_add(struct amdgpu_device *adev,
                                      struct amdgpu_vm *vm,
                                      struct amdgpu_bo *bo)
{
        struct amdgpu_bo_va *bo_va;

        bo_va = kzalloc(sizeof(struct amdgpu_bo_va), GFP_KERNEL);
        if (bo_va == NULL) {
                return NULL;
        }
        amdgpu_vm_bo_base_init(&bo_va->base, vm, bo);

        bo_va->ref_count = 1;
        INIT_LIST_HEAD(&bo_va->valids);
        INIT_LIST_HEAD(&bo_va->invalids);

        return bo_va;
}


/**
 * amdgpu_vm_bo_insert_mapping - insert a new mapping
 *
 * @adev: amdgpu_device pointer
 * @bo_va: bo_va to store the address
 * @mapping: the mapping to insert
 *
 * Insert a new mapping into all structures.
 */
static void amdgpu_vm_bo_insert_map(struct amdgpu_device *adev,
                                    struct amdgpu_bo_va *bo_va,
                                    struct amdgpu_bo_va_mapping *mapping)
{
        struct amdgpu_vm *vm = bo_va->base.vm;
        struct amdgpu_bo *bo = bo_va->base.bo;

        mapping->bo_va = bo_va;
        list_add(&mapping->list, &bo_va->invalids);
        amdgpu_vm_it_insert(mapping, &vm->va);

        if (mapping->flags & AMDGPU_PTE_PRT)
                amdgpu_vm_prt_get(adev);

        if (bo && bo->tbo.resv == vm->root.base.bo->tbo.resv &&
            !bo_va->base.moved) {
                list_move(&bo_va->base.vm_status, &vm->moved);
        }
#if 0
        trace_amdgpu_vm_bo_map(bo_va, mapping);
#endif
}

/**
 * amdgpu_vm_bo_map - map bo inside a vm
 *
 * @adev: amdgpu_device pointer
 * @bo_va: bo_va to store the address
 * @saddr: where to map the BO
 * @offset: requested offset in the BO
 * @size: BO size in bytes
 * @flags: attributes of pages (read/write/valid/etc.)
 *
 * Add a mapping of the BO at the specefied addr into the VM.
 *
 * Returns:
 * 0 for success, error for failure.
 *
 * Object has to be reserved and unreserved outside!
 */
int amdgpu_vm_bo_map(struct amdgpu_device *adev,
                     struct amdgpu_bo_va *bo_va,
                     uint64_t saddr, uint64_t offset,
                     uint64_t size, uint64_t flags)
{
        struct amdgpu_bo_va_mapping *mapping, *tmp;
        struct amdgpu_bo *bo = bo_va->base.bo;
        struct amdgpu_vm *vm = bo_va->base.vm;
        uint64_t eaddr;

        /* validate the parameters */
        if (saddr & AMDGPU_GPU_PAGE_MASK || offset & AMDGPU_GPU_PAGE_MASK ||
            size == 0 || size & AMDGPU_GPU_PAGE_MASK)
                return -EINVAL;

        /* make sure object fit at this offset */
        eaddr = saddr + size - 1;
        if (saddr >= eaddr ||
            (bo && offset + size > amdgpu_bo_size(bo)))
                return -EINVAL;

        saddr /= AMDGPU_GPU_PAGE_SIZE;
        eaddr /= AMDGPU_GPU_PAGE_SIZE;

        tmp = amdgpu_vm_it_iter_first(&vm->va, saddr, eaddr);
        if (tmp) {
                /* bo and tmp overlap, invalid addr */
                dev_err(adev->dev, "bo %p va 0x%010lx-0x%010lx conflict with "
                        "0x%010lx-0x%010lx\n", bo, saddr, eaddr,
                        tmp->start, tmp->last + 1);
                return -EINVAL;
        }

        mapping = kmalloc(sizeof(*mapping), M_DRM, GFP_KERNEL);
        if (!mapping)
                return -ENOMEM;

        mapping->start = saddr;
        mapping->last = eaddr;
        mapping->offset = offset;
        mapping->flags = flags;

        amdgpu_vm_bo_insert_map(adev, bo_va, mapping);

        return 0;
}

/**
 * amdgpu_vm_bo_replace_map - map bo inside a vm, replacing existing mappings
 *
 * @adev: amdgpu_device pointer
 * @bo_va: bo_va to store the address
 * @saddr: where to map the BO
 * @offset: requested offset in the BO
 * @size: BO size in bytes
 * @flags: attributes of pages (read/write/valid/etc.)
 *
 * Add a mapping of the BO at the specefied addr into the VM. Replace existing
 * mappings as we do so.
 *
 * Returns:
 * 0 for success, error for failure.
 *
 * Object has to be reserved and unreserved outside!
 */
int amdgpu_vm_bo_replace_map(struct amdgpu_device *adev,
                             struct amdgpu_bo_va *bo_va,
                             uint64_t saddr, uint64_t offset,
                             uint64_t size, uint64_t flags)
{
        struct amdgpu_bo_va_mapping *mapping;
        struct amdgpu_bo *bo = bo_va->base.bo;
        uint64_t eaddr;
        int r;

        /* validate the parameters */
        if (saddr & AMDGPU_GPU_PAGE_MASK || offset & AMDGPU_GPU_PAGE_MASK ||
            size == 0 || size & AMDGPU_GPU_PAGE_MASK)
                return -EINVAL;

        /* make sure object fit at this offset */
        eaddr = saddr + size - 1;
        if (saddr >= eaddr ||
            (bo && offset + size > amdgpu_bo_size(bo)))
                return -EINVAL;

        /* Allocate all the needed memory */
        mapping = kmalloc(sizeof(*mapping), M_DRM, GFP_KERNEL);
        if (!mapping)
                return -ENOMEM;

        r = amdgpu_vm_bo_clear_mappings(adev, bo_va->base.vm, saddr, size);
        if (r) {
                kfree(mapping);
                return r;
        }

        saddr /= AMDGPU_GPU_PAGE_SIZE;
        eaddr /= AMDGPU_GPU_PAGE_SIZE;

        mapping->start = saddr;
        mapping->last = eaddr;
        mapping->offset = offset;
        mapping->flags = flags;

        amdgpu_vm_bo_insert_map(adev, bo_va, mapping);

        return 0;
}

/**
 * amdgpu_vm_bo_unmap - remove bo mapping from vm
 *
 * @adev: amdgpu_device pointer
 * @bo_va: bo_va to remove the address from
 * @saddr: where to the BO is mapped
 *
 * Remove a mapping of the BO at the specefied addr from the VM.
 *
 * Returns:
 * 0 for success, error for failure.
 *
 * Object has to be reserved and unreserved outside!
 */
int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
                       struct amdgpu_bo_va *bo_va,
                       uint64_t saddr)
{
        struct amdgpu_bo_va_mapping *mapping;
        struct amdgpu_vm *vm = bo_va->base.vm;
        bool valid = true;

        saddr /= AMDGPU_GPU_PAGE_SIZE;

        list_for_each_entry(mapping, &bo_va->valids, list) {
                if (mapping->start == saddr)
                        break;
        }

        if (&mapping->list == &bo_va->valids) {
                valid = false;

                list_for_each_entry(mapping, &bo_va->invalids, list) {
                        if (mapping->start == saddr)
                                break;
                }

                if (&mapping->list == &bo_va->invalids)
                        return -ENOENT;
        }

        list_del(&mapping->list);
        amdgpu_vm_it_remove(mapping, &vm->va);
        mapping->bo_va = NULL;
        trace_amdgpu_vm_bo_unmap(bo_va, mapping);

        if (valid)
                list_add(&mapping->list, &vm->freed);
        else
                amdgpu_vm_free_mapping(adev, vm, mapping,
                                       bo_va->last_pt_update);

        return 0;
}

/**
 * amdgpu_vm_bo_clear_mappings - remove all mappings in a specific range
 *
 * @adev: amdgpu_device pointer
 * @vm: VM structure to use
 * @saddr: start of the range
 * @size: size of the range
 *
 * Remove all mappings in a range, split them as appropriate.
 *
 * Returns:
 * 0 for success, error for failure.
 */
int amdgpu_vm_bo_clear_mappings(struct amdgpu_device *adev,
                                struct amdgpu_vm *vm,
                                uint64_t saddr, uint64_t size)
{
        struct amdgpu_bo_va_mapping *before, *after, *tmp, *next;
        DRM_LIST_HEAD(removed);
        uint64_t eaddr;

        eaddr = saddr + size - 1;
        saddr /= AMDGPU_GPU_PAGE_SIZE;
        eaddr /= AMDGPU_GPU_PAGE_SIZE;

        /* Allocate all the needed memory */
        before = kzalloc(sizeof(*before), GFP_KERNEL);
        if (!before)
                return -ENOMEM;
        INIT_LIST_HEAD(&before->list);

        after = kzalloc(sizeof(*after), GFP_KERNEL);
        if (!after) {
                kfree(before);
                return -ENOMEM;
        }
        INIT_LIST_HEAD(&after->list);

        /* Now gather all removed mappings */
        tmp = amdgpu_vm_it_iter_first(&vm->va, saddr, eaddr);
        while (tmp) {
                /* Remember mapping split at the start */
                if (tmp->start < saddr) {
                        before->start = tmp->start;
                        before->last = saddr - 1;
                        before->offset = tmp->offset;
                        before->flags = tmp->flags;
                        before->bo_va = tmp->bo_va;
                        list_add(&before->list, &tmp->bo_va->invalids);
                }

                /* Remember mapping split at the end */
                if (tmp->last > eaddr) {
                        after->start = eaddr + 1;
                        after->last = tmp->last;
                        after->offset = tmp->offset;
                        after->offset += after->start - tmp->start;
                        after->flags = tmp->flags;
                        after->bo_va = tmp->bo_va;
                        list_add(&after->list, &tmp->bo_va->invalids);
                }

                list_del(&tmp->list);
                list_add(&tmp->list, &removed);

                tmp = amdgpu_vm_it_iter_next(tmp, saddr, eaddr);
        }

        /* And free them up */
        list_for_each_entry_safe(tmp, next, &removed, list) {
                amdgpu_vm_it_remove(tmp, &vm->va);
                list_del(&tmp->list);

                if (tmp->start < saddr)
                    tmp->start = saddr;
                if (tmp->last > eaddr)
                    tmp->last = eaddr;

                tmp->bo_va = NULL;
                list_add(&tmp->list, &vm->freed);
                trace_amdgpu_vm_bo_unmap(NULL, tmp);
        }

        /* Insert partial mapping before the range */
        if (!list_empty(&before->list)) {
                amdgpu_vm_it_insert(before, &vm->va);
                if (before->flags & AMDGPU_PTE_PRT)
                        amdgpu_vm_prt_get(adev);
        } else {
                kfree(before);
        }

        /* Insert partial mapping after the range */
        if (!list_empty(&after->list)) {
                amdgpu_vm_it_insert(after, &vm->va);
                if (after->flags & AMDGPU_PTE_PRT)
                        amdgpu_vm_prt_get(adev);
        } else {
                kfree(after);
        }

        return 0;
}

/**
 * amdgpu_vm_bo_lookup_mapping - find mapping by address
 *
 * @vm: the requested VM
 * @addr: the address
 *
 * Find a mapping by it's address.
 *
 * Returns:
 * The amdgpu_bo_va_mapping matching for addr or NULL
 *
 */
struct amdgpu_bo_va_mapping *amdgpu_vm_bo_lookup_mapping(struct amdgpu_vm *vm,
                                                         uint64_t addr)
{
        return amdgpu_vm_it_iter_first(&vm->va, addr, addr);
}

/**
 * amdgpu_vm_bo_trace_cs - trace all reserved mappings
 *
 * @vm: the requested vm
 * @ticket: CS ticket
 *
 * Trace all mappings of BOs reserved during a command submission.
 */
void amdgpu_vm_bo_trace_cs(struct amdgpu_vm *vm, struct ww_acquire_ctx *ticket)
{
#if 0
        struct amdgpu_bo_va_mapping *mapping;

        if (!trace_amdgpu_vm_bo_cs_enabled())
                return;

        for (mapping = amdgpu_vm_it_iter_first(&vm->va, 0, U64_MAX); mapping;
             mapping = amdgpu_vm_it_iter_next(mapping, 0, U64_MAX)) {
                if (mapping->bo_va && mapping->bo_va->base.bo) {
                        struct amdgpu_bo *bo;

                        bo = mapping->bo_va->base.bo;
                        if (READ_ONCE(bo->tbo.resv->lock.ctx) != ticket)
                                continue;
                }

                trace_amdgpu_vm_bo_cs(mapping);
        }
#endif
}

/**
 * amdgpu_vm_bo_rmv - remove a bo to a specific vm
 *
 * @adev: amdgpu_device pointer
 * @bo_va: requested bo_va
 *
 * Remove @bo_va->bo from the requested vm.
 *
 * Object have to be reserved!
 */
void amdgpu_vm_bo_rmv(struct amdgpu_device *adev,
                      struct amdgpu_bo_va *bo_va)
{
        struct amdgpu_bo_va_mapping *mapping, *next;
        struct amdgpu_bo *bo = bo_va->base.bo;
        struct amdgpu_vm *vm = bo_va->base.vm;
        struct amdgpu_vm_bo_base **base;

        if (bo) {
                if (bo->tbo.resv == vm->root.base.bo->tbo.resv)
                        vm->bulk_moveable = false;

                for (base = &bo_va->base.bo->vm_bo; *base;
                     base = &(*base)->next) {
                        if (*base != &bo_va->base)
                                continue;

                        *base = bo_va->base.next;
                        break;
                }
        }

        lockmgr(&vm->invalidated_lock, LK_EXCLUSIVE);
        list_del(&bo_va->base.vm_status);
        lockmgr(&vm->invalidated_lock, LK_RELEASE);

        list_for_each_entry_safe(mapping, next, &bo_va->valids, list) {
                list_del(&mapping->list);
                amdgpu_vm_it_remove(mapping, &vm->va);
                mapping->bo_va = NULL;
                trace_amdgpu_vm_bo_unmap(bo_va, mapping);
                list_add(&mapping->list, &vm->freed);
        }
        list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
                list_del(&mapping->list);
                amdgpu_vm_it_remove(mapping, &vm->va);
                amdgpu_vm_free_mapping(adev, vm, mapping,
                                       bo_va->last_pt_update);
        }

        dma_fence_put(bo_va->last_pt_update);
        kfree(bo_va);
}

/**
 * amdgpu_vm_bo_invalidate - mark the bo as invalid
 *
 * @adev: amdgpu_device pointer
 * @bo: amdgpu buffer object
 * @evicted: is the BO evicted
 *
 * Mark @bo as invalid.
 */
void amdgpu_vm_bo_invalidate(struct amdgpu_device *adev,
                             struct amdgpu_bo *bo, bool evicted)
{
        struct amdgpu_vm_bo_base *bo_base;

        /* shadow bo doesn't have bo base, its validation needs its parent */
        if (bo->parent && bo->parent->shadow == bo)
                bo = bo->parent;

        for (bo_base = bo->vm_bo; bo_base; bo_base = bo_base->next) {
                struct amdgpu_vm *vm = bo_base->vm;

                if (evicted && bo->tbo.resv == vm->root.base.bo->tbo.resv) {
                        amdgpu_vm_bo_evicted(bo_base);
                        continue;
                }

                if (bo_base->moved)
                        continue;
                bo_base->moved = true;

                if (bo->tbo.type == ttm_bo_type_kernel)
                        amdgpu_vm_bo_relocated(bo_base);
                else if (bo->tbo.resv == vm->root.base.bo->tbo.resv)
                        amdgpu_vm_bo_moved(bo_base);
                else
                        amdgpu_vm_bo_invalidated(bo_base);
        }
}

/**
 * amdgpu_vm_get_block_size - calculate VM page table size as power of two
 *
 * @vm_size: VM size
 *
 * Returns:
 * VM page table as power of two
 */
static uint32_t amdgpu_vm_get_block_size(uint64_t vm_size)
{
        /* Total bits covered by PD + PTs */
        unsigned bits = ilog2(vm_size) + 18;

        /* Make sure the PD is 4K in size up to 8GB address space.
           Above that split equal between PD and PTs */
        if (vm_size <= 8)
                return (bits - 9);
        else
                return ((bits + 3) / 2);
}

/**
 * amdgpu_vm_adjust_size - adjust vm size, block size and fragment size
 *
 * @adev: amdgpu_device pointer
 * @min_vm_size: the minimum vm size in GB if it's set auto
 * @fragment_size_default: Default PTE fragment size
 * @max_level: max VMPT level
 * @max_bits: max address space size in bits
 *
 */
void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint32_t min_vm_size,
                           uint32_t fragment_size_default, unsigned max_level,
                           unsigned max_bits)
{
        unsigned int max_size = 1 << (max_bits - 30);
        unsigned int vm_size;
        uint64_t tmp;

        /* adjust vm size first */
        if (amdgpu_vm_size != -1) {
                vm_size = amdgpu_vm_size;
                if (vm_size > max_size) {
                        dev_warn(adev->dev, "VM size (%d) too large, max is %u GB\n",
                                 amdgpu_vm_size, max_size);
                        vm_size = max_size;
                }
        } else {
                struct sysinfo si;
                unsigned int phys_ram_gb;

                /* Optimal VM size depends on the amount of physical
                 * RAM available. Underlying requirements and
                 * assumptions:
                 *
                 *  - Need to map system memory and VRAM from all GPUs
                 *     - VRAM from other GPUs not known here
                 *     - Assume VRAM <= system memory
                 *  - On GFX8 and older, VM space can be segmented for
                 *    different MTYPEs
                 *  - Need to allow room for fragmentation, guard pages etc.
                 *
                 * This adds up to a rough guess of system memory x3.
                 * Round up to power of two to maximize the available
                 * VM size with the given page table size.
                 */
                si_meminfo(&si);
                phys_ram_gb = ((uint64_t)si.totalram * si.mem_unit +
                               (1 << 30) - 1) >> 30;
                vm_size = roundup_pow_of_two(
                        min(max(phys_ram_gb * 3, min_vm_size), max_size));
        }

        adev->vm_manager.max_pfn = (uint64_t)vm_size << 18;

        tmp = roundup_pow_of_two(adev->vm_manager.max_pfn);
        if (amdgpu_vm_block_size != -1)
                tmp >>= amdgpu_vm_block_size - 9;
        tmp = DIV_ROUND_UP(fls64(tmp) - 1, 9) - 1;
        adev->vm_manager.num_level = min(max_level, (unsigned)tmp);
        switch (adev->vm_manager.num_level) {
        case 3:
                adev->vm_manager.root_level = AMDGPU_VM_PDB2;
                break;
        case 2:
                adev->vm_manager.root_level = AMDGPU_VM_PDB1;
                break;
        case 1:
                adev->vm_manager.root_level = AMDGPU_VM_PDB0;
                break;
        default:
                dev_err(adev->dev, "VMPT only supports 2~4+1 levels\n");
        }
        /* block size depends on vm size and hw setup*/
        if (amdgpu_vm_block_size != -1)
                adev->vm_manager.block_size =
                        min((unsigned)amdgpu_vm_block_size, max_bits
                            - AMDGPU_GPU_PAGE_SHIFT
                            - 9 * adev->vm_manager.num_level);
        else if (adev->vm_manager.num_level > 1)
                adev->vm_manager.block_size = 9;
        else
                adev->vm_manager.block_size = amdgpu_vm_get_block_size(tmp);

        if (amdgpu_vm_fragment_size == -1)
                adev->vm_manager.fragment_size = fragment_size_default;
        else
                adev->vm_manager.fragment_size = amdgpu_vm_fragment_size;

        DRM_INFO("vm size is %u GB, %u levels, block size is %u-bit, fragment size is %u-bit\n",
                 vm_size, adev->vm_manager.num_level + 1,
                 adev->vm_manager.block_size,
                 adev->vm_manager.fragment_size);
}

static struct amdgpu_retryfault_hashtable *init_fault_hash(void)
{
        struct amdgpu_retryfault_hashtable *fault_hash;

        fault_hash = kmalloc(sizeof(*fault_hash), M_DRM, GFP_KERNEL);
        if (!fault_hash)
                return fault_hash;

        INIT_CHASH_TABLE(fault_hash->hash,
                        AMDGPU_PAGEFAULT_HASH_BITS, 8, 0);
        lockinit(&fault_hash->lock, "agvmfhl", 0, LK_CANRECURSE);
        fault_hash->count = 0;

        return fault_hash;
}

/**
 * amdgpu_vm_init - initialize a vm instance
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 * @vm_context: Indicates if it GFX or Compute context
 * @pasid: Process address space identifier
 *
 * Init @vm fields.
 *
 * Returns:
 * 0 for success, error for failure.
 */
int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                   int vm_context, unsigned int pasid)
{
        struct amdgpu_bo_param bp;
        struct amdgpu_bo *root;
        int r, i;

        vm->va = LINUX_RB_ROOT_CACHED;
        for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
                vm->reserved_vmid[i] = NULL;
        INIT_LIST_HEAD(&vm->evicted);
        INIT_LIST_HEAD(&vm->relocated);
        INIT_LIST_HEAD(&vm->moved);
        INIT_LIST_HEAD(&vm->idle);
        INIT_LIST_HEAD(&vm->invalidated);
        lockinit(&vm->invalidated_lock, "agvmil", 0, LK_CANRECURSE);
        INIT_LIST_HEAD(&vm->freed);

        /* create scheduler entity for page table updates */
        r = drm_sched_entity_init(&vm->entity, adev->vm_manager.vm_pte_rqs,
                                  adev->vm_manager.vm_pte_num_rqs, NULL);
        if (r)
                return r;

        vm->pte_support_ats = false;

        if (vm_context == AMDGPU_VM_CONTEXT_COMPUTE) {
                vm->use_cpu_for_update = !!(adev->vm_manager.vm_update_mode &
                                                AMDGPU_VM_USE_CPU_FOR_COMPUTE);

                if (adev->asic_type == CHIP_RAVEN)
                        vm->pte_support_ats = true;
        } else {
                vm->use_cpu_for_update = !!(adev->vm_manager.vm_update_mode &
                                                AMDGPU_VM_USE_CPU_FOR_GFX);
        }
        DRM_DEBUG_DRIVER("VM update mode is %s\n",
                         vm->use_cpu_for_update ? "CPU" : "SDMA");
        WARN_ONCE((vm->use_cpu_for_update & !amdgpu_gmc_vram_full_visible(&adev->gmc)),
                  "CPU update of VM recommended only for large BAR system\n");
        vm->last_update = NULL;

        amdgpu_vm_bo_param(adev, vm, adev->vm_manager.root_level, &bp);
        if (vm_context == AMDGPU_VM_CONTEXT_COMPUTE)
                bp.flags &= ~AMDGPU_GEM_CREATE_SHADOW;
        r = amdgpu_bo_create(adev, &bp, &root);
        if (r)
                goto error_free_sched_entity;

        r = amdgpu_bo_reserve(root, true);
        if (r)
                goto error_free_root;

        r = amdgpu_vm_clear_bo(adev, vm, root,
                               adev->vm_manager.root_level,
                               vm->pte_support_ats);
        if (r)
                goto error_unreserve;

        amdgpu_vm_bo_base_init(&vm->root.base, vm, root);
        amdgpu_bo_unreserve(vm->root.base.bo);

        if (pasid) {
                unsigned long flags;

                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
                r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
                              GFP_ATOMIC);
                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
                if (r < 0)
                        goto error_free_root;

                vm->pasid = pasid;
        }

        vm->fault_hash = init_fault_hash();
        if (!vm->fault_hash) {
                r = -ENOMEM;
                goto error_free_root;
        }

#if 0
        INIT_KFIFO(vm->faults);
#endif
        vm->fault_credit = 16;

        return 0;

error_unreserve:
        amdgpu_bo_unreserve(vm->root.base.bo);

error_free_root:
        amdgpu_bo_unref(&vm->root.base.bo->shadow);
        amdgpu_bo_unref(&vm->root.base.bo);
        vm->root.base.bo = NULL;

error_free_sched_entity:
        drm_sched_entity_destroy(&vm->entity);

        return r;
}

/**
 * amdgpu_vm_make_compute - Turn a GFX VM into a compute VM
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * This only works on GFX VMs that don't have any BOs added and no
 * page tables allocated yet.
 *
 * Changes the following VM parameters:
 * - use_cpu_for_update
 * - pte_supports_ats
 * - pasid (old PASID is released, because compute manages its own PASIDs)
 *
 * Reinitializes the page directory to reflect the changed ATS
 * setting.
 *
 * Returns:
 * 0 for success, -errno for errors.
 */
int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm, unsigned int pasid)
{
        bool pte_support_ats = (adev->asic_type == CHIP_RAVEN);
        int r;

        r = amdgpu_bo_reserve(vm->root.base.bo, true);
        if (r)
                return r;

        /* Sanity checks */
        if (!RB_EMPTY_ROOT(&vm->va.rb_root) || vm->root.entries) {
                r = -EINVAL;
                goto unreserve_bo;
        }

        if (pasid) {
                unsigned long flags;

                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
                r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
                              GFP_ATOMIC);
                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);

                if (r == -ENOSPC)
                        goto unreserve_bo;
                r = 0;
        }

        /* Check if PD needs to be reinitialized and do it before
         * changing any other state, in case it fails.
         */
        if (pte_support_ats != vm->pte_support_ats) {
                r = amdgpu_vm_clear_bo(adev, vm, vm->root.base.bo,
                               adev->vm_manager.root_level,
                               pte_support_ats);
                if (r)
                        goto free_idr;
        }

        /* Update VM state */
        vm->use_cpu_for_update = !!(adev->vm_manager.vm_update_mode &
                                    AMDGPU_VM_USE_CPU_FOR_COMPUTE);
        vm->pte_support_ats = pte_support_ats;
        DRM_DEBUG_DRIVER("VM update mode is %s\n",
                         vm->use_cpu_for_update ? "CPU" : "SDMA");
        WARN_ONCE((vm->use_cpu_for_update & !amdgpu_gmc_vram_full_visible(&adev->gmc)),
                  "CPU update of VM recommended only for large BAR system\n");

        if (vm->pasid) {
                unsigned long flags;

                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
                idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);

                /* Free the original amdgpu allocated pasid
                 * Will be replaced with kfd allocated pasid
                 */
                amdgpu_pasid_free(vm->pasid);
                vm->pasid = 0;
        }

        /* Free the shadow bo for compute VM */
        amdgpu_bo_unref(&vm->root.base.bo->shadow);

        if (pasid)
                vm->pasid = pasid;

        goto unreserve_bo;

free_idr:
        if (pasid) {
                unsigned long flags;

                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
                idr_remove(&adev->vm_manager.pasid_idr, pasid);
                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
        }
unreserve_bo:
        amdgpu_bo_unreserve(vm->root.base.bo);
        return r;
}

/**
 * amdgpu_vm_release_compute - release a compute vm
 * @adev: amdgpu_device pointer
 * @vm: a vm turned into compute vm by calling amdgpu_vm_make_compute
 *
 * This is a correspondant of amdgpu_vm_make_compute. It decouples compute
 * pasid from vm. Compute should stop use of vm after this call.
 */
void amdgpu_vm_release_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
{
        if (vm->pasid) {
                unsigned long flags;

                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
                idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
        }
        vm->pasid = 0;
}

/**
 * amdgpu_vm_fini - tear down a vm instance
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * Tear down @vm.
 * Unbind the VM and remove all bos from the vm bo list
 */
void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
{
        struct amdgpu_bo_va_mapping *mapping, *tmp;
        bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
        struct amdgpu_bo *root;
#if 0
        u64 fault;
#endif
        int i, r;

        amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);

#if 0
        /* Clear pending page faults from IH when the VM is destroyed */
        while (kfifo_get(&vm->faults, &fault))
                amdgpu_ih_clear_fault(adev, fault);
#endif

        if (vm->pasid) {
                unsigned long flags;

                spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
                idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
                spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
        }

        kfree(vm->fault_hash);
        vm->fault_hash = NULL;

        drm_sched_entity_destroy(&vm->entity);

        if (!RB_EMPTY_ROOT(&vm->va.rb_root)) {
                dev_err(adev->dev, "still active bo inside vm\n");
        }
#ifndef __DragonFly__
        rbtree_postorder_for_each_entry_safe(mapping, tmp,
                                             &vm->va.rb_root, rb) {
#else
        /*
         * DFly interval tree mock-up does not use RB trees, the RB iterator
         * can not be used.
         * This code is removing all entries so it is fairly easy to replace.
         */
        while (vm->va.rb_leftmost) {
                mapping = container_of((void *)vm->va.rb_leftmost, struct amdgpu_bo_va_mapping, rb);
#endif
                /* Don't remove the mapping here, we don't want to trigger a
                 * rebalance and the tree is about to be destroyed anyway.
                 */
                list_del(&mapping->list);
                amdgpu_vm_it_remove(mapping, &vm->va);
                kfree(mapping);
        }
        list_for_each_entry_safe(mapping, tmp, &vm->freed, list) {
                if (mapping->flags & AMDGPU_PTE_PRT && prt_fini_needed) {
                        amdgpu_vm_prt_fini(adev, vm);
                        prt_fini_needed = false;
                }

                list_del(&mapping->list);
                amdgpu_vm_free_mapping(adev, vm, mapping, NULL);
        }

        root = amdgpu_bo_ref(vm->root.base.bo);
        r = amdgpu_bo_reserve(root, true);
        if (r) {
                dev_err(adev->dev, "Leaking page tables because BO reservation failed\n");
        } else {
                amdgpu_vm_free_pts(adev, vm);
                amdgpu_bo_unreserve(root);
        }
        amdgpu_bo_unref(&root);
        dma_fence_put(vm->last_update);
        for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
                amdgpu_vmid_free_reserved(adev, vm, i);
}

/**
 * amdgpu_vm_pasid_fault_credit - Check fault credit for given PASID
 *
 * @adev: amdgpu_device pointer
 * @pasid: PASID do identify the VM
 *
 * This function is expected to be called in interrupt context.
 *
 * Returns:
 * True if there was fault credit, false otherwise
 */
bool amdgpu_vm_pasid_fault_credit(struct amdgpu_device *adev,
                                  unsigned int pasid)
{
        struct amdgpu_vm *vm;

        lockmgr(&adev->vm_manager.pasid_lock, LK_EXCLUSIVE);
        vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
        if (!vm) {
                /* VM not found, can't track fault credit */
                lockmgr(&adev->vm_manager.pasid_lock, LK_RELEASE);
                return true;
        }

        /* No lock needed. only accessed by IRQ handler */
        if (!vm->fault_credit) {
                /* Too many faults in this VM */
                lockmgr(&adev->vm_manager.pasid_lock, LK_RELEASE);
                return false;
        }

        vm->fault_credit--;
        lockmgr(&adev->vm_manager.pasid_lock, LK_RELEASE);
        return true;
}

/**
 * amdgpu_vm_manager_init - init the VM manager
 *
 * @adev: amdgpu_device pointer
 *
 * Initialize the VM manager structures
 */
void amdgpu_vm_manager_init(struct amdgpu_device *adev)
{
        unsigned i;

        amdgpu_vmid_mgr_init(adev);

        adev->vm_manager.fence_context =
                dma_fence_context_alloc(AMDGPU_MAX_RINGS);
        for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
                adev->vm_manager.seqno[i] = 0;

        lockinit(&adev->vm_manager.prt_lock, "agvmmprtl", 0, LK_CANRECURSE);
        atomic_set(&adev->vm_manager.num_prt_users, 0);

        /* If not overridden by the user, by default, only in large BAR systems
         * Compute VM tables will be updated by CPU
         */
#ifdef CONFIG_X86_64
        if (amdgpu_vm_update_mode == -1) {
                if (amdgpu_gmc_vram_full_visible(&adev->gmc))
                        adev->vm_manager.vm_update_mode =
                                AMDGPU_VM_USE_CPU_FOR_COMPUTE;
                else
                        adev->vm_manager.vm_update_mode = 0;
        } else
                adev->vm_manager.vm_update_mode = amdgpu_vm_update_mode;
#else
        adev->vm_manager.vm_update_mode = 0;
#endif

        idr_init(&adev->vm_manager.pasid_idr);
        lockinit(&adev->vm_manager.pasid_lock, "agvmmpl", 0, LK_CANRECURSE);
}

/**
 * amdgpu_vm_manager_fini - cleanup VM manager
 *
 * @adev: amdgpu_device pointer
 *
 * Cleanup the VM manager and free resources.
 */
void amdgpu_vm_manager_fini(struct amdgpu_device *adev)
{
#if 0
        WARN_ON(!idr_is_empty(&adev->vm_manager.pasid_idr));
#endif
        idr_destroy(&adev->vm_manager.pasid_idr);

        amdgpu_vmid_mgr_fini(adev);
}

/**
 * amdgpu_vm_ioctl - Manages VMID reservation for vm hubs.
 *
 * @dev: drm device pointer
 * @data: drm_amdgpu_vm
 * @filp: drm file pointer
 *
 * Returns:
 * 0 for success, -errno for errors.
 */
int amdgpu_vm_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
{
        union drm_amdgpu_vm *args = data;
        struct amdgpu_device *adev = dev->dev_private;
        struct amdgpu_fpriv *fpriv = filp->driver_priv;
        int r;

        switch (args->in.op) {
        case AMDGPU_VM_OP_RESERVE_VMID:
                /* current, we only have requirement to reserve vmid from gfxhub */
                r = amdgpu_vmid_alloc_reserved(adev, &fpriv->vm, AMDGPU_GFXHUB);
                if (r)
                        return r;
                break;
        case AMDGPU_VM_OP_UNRESERVE_VMID:
                amdgpu_vmid_free_reserved(adev, &fpriv->vm, AMDGPU_GFXHUB);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

/**
 * amdgpu_vm_get_task_info - Extracts task info for a PASID.
 *
 * @adev: drm device pointer
 * @pasid: PASID identifier for VM
 * @task_info: task_info to fill.
 */
void amdgpu_vm_get_task_info(struct amdgpu_device *adev, unsigned int pasid,
                         struct amdgpu_task_info *task_info)
{
        struct amdgpu_vm *vm;
        unsigned long flags;

        spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);

        vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
        if (vm)
                *task_info = vm->task_info;

        spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
}

/**
 * amdgpu_vm_set_task_info - Sets VMs task info.
 *
 * @vm: vm for which to set the info
 */
void amdgpu_vm_set_task_info(struct amdgpu_vm *vm)
{
        kprintf("amdgpu_vm_set_task_info: not implemented\n");
#if 0
        if (!vm->task_info.pid) {
                vm->task_info.pid = current->pid;
                get_task_comm(vm->task_info.task_name, current);

                if (current->group_leader->mm == current->mm) {
                        vm->task_info.tgid = current->group_leader->pid;
                        get_task_comm(vm->task_info.process_name, current->group_leader);
                }
        }
#endif
}

/**
 * amdgpu_vm_add_fault - Add a page fault record to fault hash table
 *
 * @fault_hash: fault hash table
 * @key: 64-bit encoding of PASID and address
 *
 * This should be called when a retry page fault interrupt is
 * received. If this is a new page fault, it will be added to a hash
 * table. The return value indicates whether this is a new fault, or
 * a fault that was already known and is already being handled.
 *
 * If there are too many pending page faults, this will fail. Retry
 * interrupts should be ignored in this case until there is enough
 * free space.
 *
 * Returns 0 if the fault was added, 1 if the fault was already known,
 * -ENOSPC if there are too many pending faults.
 */
int amdgpu_vm_add_fault(struct amdgpu_retryfault_hashtable *fault_hash, u64 key)
{
        unsigned long flags;
        int r = -ENOSPC;

        if (WARN_ON_ONCE(!fault_hash))
                /* Should be allocated in amdgpu_vm_init
                 */
                return r;

        spin_lock_irqsave(&fault_hash->lock, flags);

        /* Only let the hash table fill up to 50% for best performance */
        if (fault_hash->count >= (1 << (AMDGPU_PAGEFAULT_HASH_BITS-1)))
                goto unlock_out;

        r = chash_table_copy_in(&fault_hash->hash, key, NULL);
        if (!r)
                fault_hash->count++;

        /* chash_table_copy_in should never fail unless we're losing count */
        WARN_ON_ONCE(r < 0);

unlock_out:
        spin_unlock_irqrestore(&fault_hash->lock, flags);
        return r;
}

/**
 * amdgpu_vm_clear_fault - Remove a page fault record
 *
 * @fault_hash: fault hash table
 * @key: 64-bit encoding of PASID and address
 *
 * This should be called when a page fault has been handled. Any
 * future interrupt with this key will be processed as a new
 * page fault.
 */
void amdgpu_vm_clear_fault(struct amdgpu_retryfault_hashtable *fault_hash, u64 key)
{
        unsigned long flags;
        int r;

        if (!fault_hash)
                return;

        spin_lock_irqsave(&fault_hash->lock, flags);

        r = chash_table_remove(&fault_hash->hash, key, NULL);
        if (!WARN_ON_ONCE(r < 0)) {
                fault_hash->count--;
                WARN_ON_ONCE(fault_hash->count < 0);
        }

        spin_unlock_irqrestore(&fault_hash->lock, flags);
}