drm/amdgpu: use a 64bit interval tree for VM management v2

[karo-tx-linux.git] / drivers / gpu / drm / amd / amdgpu / amdgpu_vm.c

/*
 * 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 <drm/drmP.h>
#include <drm/amdgpu_drm.h>
#include "amdgpu.h"
#include "amdgpu_trace.h"

/*
 * 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)

INTERVAL_TREE_DEFINE(struct amdgpu_bo_va_mapping, rb, uint64_t, __subtree_last,
                     START, LAST, static, amdgpu_vm_it)

#undef START
#undef LAST

/* Local structure. Encapsulate some VM table update parameters to reduce
 * the number of function parameters
 */
struct amdgpu_pte_update_params {
        /* amdgpu device we do this update for */
        struct amdgpu_device *adev;
        /* optional amdgpu_vm we do this update for */
        struct amdgpu_vm *vm;
        /* address where to copy page table entries from */
        uint64_t src;
        /* indirect buffer to fill with commands */
        struct amdgpu_ib *ib;
        /* Function which actually does the update */
        void (*func)(struct amdgpu_pte_update_params *params, uint64_t pe,
                     uint64_t addr, unsigned count, uint32_t incr,
                     uint64_t flags);
        /* indicate update pt or its shadow */
        bool shadow;
};

/* Helper to disable partial resident texture feature from a fence callback */
struct amdgpu_prt_cb {
        struct amdgpu_device *adev;
        struct dma_fence_cb cb;
};

/**
 * amdgpu_vm_num_entries - return the number of entries in a PD/PT
 *
 * @adev: amdgpu_device pointer
 *
 * Calculate the number of entries in a page directory or page table.
 */
static unsigned amdgpu_vm_num_entries(struct amdgpu_device *adev,
                                      unsigned level)
{
        if (level == 0)
                /* For the root directory */
                return adev->vm_manager.max_pfn >>
                        (amdgpu_vm_block_size * adev->vm_manager.num_level);
        else if (level == adev->vm_manager.num_level)
                /* For the page tables on the leaves */
                return AMDGPU_VM_PTE_COUNT;
        else
                /* Everything in between */
                return 1 << amdgpu_vm_block_size;
}

/**
 * amdgpu_vm_bo_size - returns the size of the BOs in bytes
 *
 * @adev: amdgpu_device pointer
 *
 * Calculate 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_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->robj = vm->root.bo;
        entry->priority = 0;
        entry->tv.bo = &entry->robj->tbo;
        entry->tv.shared = true;
        entry->user_pages = NULL;
        list_add(&entry->tv.head, validated);
}

/**
 * amdgpu_vm_validate_layer - validate a single page table level
 *
 * @parent: parent page table level
 * @validate: callback to do the validation
 * @param: parameter for the validation callback
 *
 * Validate the page table BOs on command submission if neccessary.
 */
static int amdgpu_vm_validate_level(struct amdgpu_vm_pt *parent,
                                    int (*validate)(void *, struct amdgpu_bo *),
                                    void *param)
{
        unsigned i;
        int r;

        if (!parent->entries)
                return 0;

        for (i = 0; i <= parent->last_entry_used; ++i) {
                struct amdgpu_vm_pt *entry = &parent->entries[i];

                if (!entry->bo)
                        continue;

                r = validate(param, entry->bo);
                if (r)
                        return r;

                /*
                 * Recurse into the sub directory. This is harmless because we
                 * have only a maximum of 5 layers.
                 */
                r = amdgpu_vm_validate_level(entry, validate, param);
                if (r)
                        return r;
        }

        return r;
}

/**
 * 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.
 */
int amdgpu_vm_validate_pt_bos(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                              int (*validate)(void *p, struct amdgpu_bo *bo),
                              void *param)
{
        uint64_t num_evictions;

        /* We only need to validate the page tables
         * if they aren't already valid.
         */
        num_evictions = atomic64_read(&adev->num_evictions);
        if (num_evictions == vm->last_eviction_counter)
                return 0;

        return amdgpu_vm_validate_level(&vm->root, validate, param);
}

/**
 * amdgpu_vm_move_level_in_lru - move one level of PT BOs to the LRU tail
 *
 * @adev: amdgpu device instance
 * @vm: vm providing the BOs
 *
 * Move the PT BOs to the tail of the LRU.
 */
static void amdgpu_vm_move_level_in_lru(struct amdgpu_vm_pt *parent)
{
        unsigned i;

        if (!parent->entries)
                return;

        for (i = 0; i <= parent->last_entry_used; ++i) {
                struct amdgpu_vm_pt *entry = &parent->entries[i];

                if (!entry->bo)
                        continue;

                ttm_bo_move_to_lru_tail(&entry->bo->tbo);
                amdgpu_vm_move_level_in_lru(entry);
        }
}

/**
 * amdgpu_vm_move_pt_bos_in_lru - move the PT BOs to the LRU tail
 *
 * @adev: amdgpu device instance
 * @vm: vm providing the BOs
 *
 * Move the PT BOs to the tail of the LRU.
 */
void amdgpu_vm_move_pt_bos_in_lru(struct amdgpu_device *adev,
                                  struct amdgpu_vm *vm)
{
        struct ttm_bo_global *glob = adev->mman.bdev.glob;

        spin_lock(&glob->lru_lock);
        amdgpu_vm_move_level_in_lru(&vm->root);
        spin_unlock(&glob->lru_lock);
}

 /**
 * amdgpu_vm_alloc_levels - allocate the PD/PT levels
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 * @saddr: start of the address range
 * @eaddr: end of the address range
 *
 * Make sure the page directories and page tables are allocated
 */
static int amdgpu_vm_alloc_levels(struct amdgpu_device *adev,
                                  struct amdgpu_vm *vm,
                                  struct amdgpu_vm_pt *parent,
                                  uint64_t saddr, uint64_t eaddr,
                                  unsigned level)
{
        unsigned shift = (adev->vm_manager.num_level - level) *
                amdgpu_vm_block_size;
        unsigned pt_idx, from, to;
        int r;

        if (!parent->entries) {
                unsigned num_entries = amdgpu_vm_num_entries(adev, level);

                parent->entries = drm_calloc_large(num_entries,
                                                   sizeof(struct amdgpu_vm_pt));
                if (!parent->entries)
                        return -ENOMEM;
                memset(parent->entries, 0 , sizeof(struct amdgpu_vm_pt));
        }

        from = saddr >> shift;
        to = eaddr >> shift;
        if (from >= amdgpu_vm_num_entries(adev, level) ||
            to >= amdgpu_vm_num_entries(adev, level))
                return -EINVAL;

        if (to > parent->last_entry_used)
                parent->last_entry_used = to;

        ++level;
        saddr = saddr & ((1 << shift) - 1);
        eaddr = eaddr & ((1 << shift) - 1);

        /* walk over the address space and allocate the page tables */
        for (pt_idx = from; pt_idx <= to; ++pt_idx) {
                struct reservation_object *resv = vm->root.bo->tbo.resv;
                struct amdgpu_vm_pt *entry = &parent->entries[pt_idx];
                struct amdgpu_bo *pt;

                if (!entry->bo) {
                        r = amdgpu_bo_create(adev,
                                             amdgpu_vm_bo_size(adev, level),
                                             AMDGPU_GPU_PAGE_SIZE, true,
                                             AMDGPU_GEM_DOMAIN_VRAM,
                                             AMDGPU_GEM_CREATE_NO_CPU_ACCESS |
                                             AMDGPU_GEM_CREATE_SHADOW |
                                             AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS |
                                             AMDGPU_GEM_CREATE_VRAM_CLEARED,
                                             NULL, resv, &pt);
                        if (r)
                                return r;

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

                        entry->bo = pt;
                        entry->addr = 0;
                }

                if (level < adev->vm_manager.num_level) {
                        uint64_t sub_saddr = (pt_idx == from) ? saddr : 0;
                        uint64_t sub_eaddr = (pt_idx == to) ? eaddr :
                                ((1 << shift) - 1);
                        r = amdgpu_vm_alloc_levels(adev, vm, entry, sub_saddr,
                                                   sub_eaddr, level);
                        if (r)
                                return r;
                }
        }

        return 0;
}

/**
 * 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 tables are allocated.
 */
int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
                        struct amdgpu_vm *vm,
                        uint64_t saddr, uint64_t size)
{
        uint64_t last_pfn;
        uint64_t eaddr;

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

        eaddr = saddr + size - 1;
        last_pfn = eaddr / AMDGPU_GPU_PAGE_SIZE;
        if (last_pfn >= adev->vm_manager.max_pfn) {
                dev_err(adev->dev, "va above limit (0x%08llX >= 0x%08llX)\n",
                        last_pfn, adev->vm_manager.max_pfn);
                return -EINVAL;
        }

        saddr /= AMDGPU_GPU_PAGE_SIZE;
        eaddr /= AMDGPU_GPU_PAGE_SIZE;

        return amdgpu_vm_alloc_levels(adev, vm, &vm->root, saddr, eaddr, 0);
}

static bool amdgpu_vm_is_gpu_reset(struct amdgpu_device *adev,
                              struct amdgpu_vm_id *id)
{
        return id->current_gpu_reset_count !=
                atomic_read(&adev->gpu_reset_counter) ? true : false;
}

/**
 * amdgpu_vm_grab_id - allocate the next free VMID
 *
 * @vm: vm to allocate id for
 * @ring: ring we want to submit job to
 * @sync: sync object where we add dependencies
 * @fence: fence protecting ID from reuse
 *
 * Allocate an id for the vm, adding fences to the sync obj as necessary.
 */
int amdgpu_vm_grab_id(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
                      struct amdgpu_sync *sync, struct dma_fence *fence,
                      struct amdgpu_job *job)
{
        struct amdgpu_device *adev = ring->adev;
        uint64_t fence_context = adev->fence_context + ring->idx;
        struct dma_fence *updates = sync->last_vm_update;
        struct amdgpu_vm_id *id, *idle;
        struct dma_fence **fences;
        unsigned i;
        int r = 0;

        fences = kmalloc_array(sizeof(void *), adev->vm_manager.num_ids,
                               GFP_KERNEL);
        if (!fences)
                return -ENOMEM;

        mutex_lock(&adev->vm_manager.lock);

        /* Check if we have an idle VMID */
        i = 0;
        list_for_each_entry(idle, &adev->vm_manager.ids_lru, list) {
                fences[i] = amdgpu_sync_peek_fence(&idle->active, ring);
                if (!fences[i])
                        break;
                ++i;
        }

        /* If we can't find a idle VMID to use, wait till one becomes available */
        if (&idle->list == &adev->vm_manager.ids_lru) {
                u64 fence_context = adev->vm_manager.fence_context + ring->idx;
                unsigned seqno = ++adev->vm_manager.seqno[ring->idx];
                struct dma_fence_array *array;
                unsigned j;

                for (j = 0; j < i; ++j)
                        dma_fence_get(fences[j]);

                array = dma_fence_array_create(i, fences, fence_context,
                                           seqno, true);
                if (!array) {
                        for (j = 0; j < i; ++j)
                                dma_fence_put(fences[j]);
                        kfree(fences);
                        r = -ENOMEM;
                        goto error;
                }


                r = amdgpu_sync_fence(ring->adev, sync, &array->base);
                dma_fence_put(&array->base);
                if (r)
                        goto error;

                mutex_unlock(&adev->vm_manager.lock);
                return 0;

        }
        kfree(fences);

        job->vm_needs_flush = true;
        /* Check if we can use a VMID already assigned to this VM */
        i = ring->idx;
        do {
                struct dma_fence *flushed;

                id = vm->ids[i++];
                if (i == AMDGPU_MAX_RINGS)
                        i = 0;

                /* Check all the prerequisites to using this VMID */
                if (!id)
                        continue;
                if (amdgpu_vm_is_gpu_reset(adev, id))
                        continue;

                if (atomic64_read(&id->owner) != vm->client_id)
                        continue;

                if (job->vm_pd_addr != id->pd_gpu_addr)
                        continue;

                if (!id->last_flush)
                        continue;

                if (id->last_flush->context != fence_context &&
                    !dma_fence_is_signaled(id->last_flush))
                        continue;

                flushed  = id->flushed_updates;
                if (updates &&
                    (!flushed || dma_fence_is_later(updates, flushed)))
                        continue;

                /* Good we can use this VMID. Remember this submission as
                 * user of the VMID.
                 */
                r = amdgpu_sync_fence(ring->adev, &id->active, fence);
                if (r)
                        goto error;

                id->current_gpu_reset_count = atomic_read(&adev->gpu_reset_counter);
                list_move_tail(&id->list, &adev->vm_manager.ids_lru);
                vm->ids[ring->idx] = id;

                job->vm_id = id - adev->vm_manager.ids;
                job->vm_needs_flush = false;
                trace_amdgpu_vm_grab_id(vm, ring->idx, job);

                mutex_unlock(&adev->vm_manager.lock);
                return 0;

        } while (i != ring->idx);

        /* Still no ID to use? Then use the idle one found earlier */
        id = idle;

        /* Remember this submission as user of the VMID */
        r = amdgpu_sync_fence(ring->adev, &id->active, fence);
        if (r)
                goto error;

        dma_fence_put(id->first);
        id->first = dma_fence_get(fence);

        dma_fence_put(id->last_flush);
        id->last_flush = NULL;

        dma_fence_put(id->flushed_updates);
        id->flushed_updates = dma_fence_get(updates);

        id->pd_gpu_addr = job->vm_pd_addr;
        id->current_gpu_reset_count = atomic_read(&adev->gpu_reset_counter);
        list_move_tail(&id->list, &adev->vm_manager.ids_lru);
        atomic64_set(&id->owner, vm->client_id);
        vm->ids[ring->idx] = id;

        job->vm_id = id - adev->vm_manager.ids;
        trace_amdgpu_vm_grab_id(vm, ring->idx, job);

error:
        mutex_unlock(&adev->vm_manager.lock);
        return r;
}

static bool amdgpu_vm_ring_has_compute_vm_bug(struct amdgpu_ring *ring)
{
        struct amdgpu_device *adev = ring->adev;
        const struct amdgpu_ip_block *ip_block;

        if (ring->funcs->type != AMDGPU_RING_TYPE_COMPUTE)
                /* only compute rings */
                return false;

        ip_block = amdgpu_get_ip_block(adev, AMD_IP_BLOCK_TYPE_GFX);
        if (!ip_block)
                return false;

        if (ip_block->version->major <= 7) {
                /* gfx7 has no workaround */
                return true;
        } else if (ip_block->version->major == 8) {
                if (adev->gfx.mec_fw_version >= 673)
                        /* gfx8 is fixed in MEC firmware 673 */
                        return false;
                else
                        return true;
        }
        return false;
}

static u64 amdgpu_vm_adjust_mc_addr(struct amdgpu_device *adev, u64 mc_addr)
{
        u64 addr = mc_addr;

        if (adev->mc.mc_funcs && adev->mc.mc_funcs->adjust_mc_addr)
                addr = adev->mc.mc_funcs->adjust_mc_addr(adev, addr);

        return addr;
}

/**
 * amdgpu_vm_flush - hardware flush the vm
 *
 * @ring: ring to use for flush
 * @vm_id: vmid number to use
 * @pd_addr: address of the page directory
 *
 * Emit a VM flush when it is necessary.
 */
int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job)
{
        struct amdgpu_device *adev = ring->adev;
        struct amdgpu_vm_id *id = &adev->vm_manager.ids[job->vm_id];
        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);
        int r;

        if (job->vm_needs_flush || gds_switch_needed ||
                amdgpu_vm_is_gpu_reset(adev, id) ||
                amdgpu_vm_ring_has_compute_vm_bug(ring)) {
                unsigned patch_offset = 0;

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

                if (ring->funcs->emit_pipeline_sync &&
                        (job->vm_needs_flush || gds_switch_needed ||
                        amdgpu_vm_ring_has_compute_vm_bug(ring)))
                        amdgpu_ring_emit_pipeline_sync(ring);

                if (ring->funcs->emit_vm_flush && (job->vm_needs_flush ||
                        amdgpu_vm_is_gpu_reset(adev, id))) {
                        struct dma_fence *fence;
                        u64 pd_addr = amdgpu_vm_adjust_mc_addr(adev, job->vm_pd_addr);

                        trace_amdgpu_vm_flush(pd_addr, ring->idx, job->vm_id);
                        amdgpu_ring_emit_vm_flush(ring, job->vm_id, pd_addr);

                        r = amdgpu_fence_emit(ring, &fence);
                        if (r)
                                return r;

                        mutex_lock(&adev->vm_manager.lock);
                        dma_fence_put(id->last_flush);
                        id->last_flush = fence;
                        mutex_unlock(&adev->vm_manager.lock);
                }

                if (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->vm_id,
                                                        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_reset_id - reset VMID to zero
 *
 * @adev: amdgpu device structure
 * @vm_id: vmid number to use
 *
 * Reset saved GDW, GWS and OA to force switch on next flush.
 */
void amdgpu_vm_reset_id(struct amdgpu_device *adev, unsigned vm_id)
{
        struct amdgpu_vm_id *id = &adev->vm_manager.ids[vm_id];

        id->gds_base = 0;
        id->gds_size = 0;
        id->gws_base = 0;
        id->gws_size = 0;
        id->oa_base = 0;
        id->oa_size = 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!
 */
struct amdgpu_bo_va *amdgpu_vm_bo_find(struct amdgpu_vm *vm,
                                       struct amdgpu_bo *bo)
{
        struct amdgpu_bo_va *bo_va;

        list_for_each_entry(bo_va, &bo->va, bo_list) {
                if (bo_va->vm == vm) {
                        return bo_va;
                }
        }
        return NULL;
}

/**
 * amdgpu_vm_do_set_ptes - helper to call the right asic function
 *
 * @params: see amdgpu_pte_update_params definition
 * @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,
                                  uint64_t pe, uint64_t addr,
                                  unsigned count, uint32_t incr,
                                  uint64_t flags)
{
        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
 * @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,
                                   uint64_t pe, uint64_t addr,
                                   unsigned count, uint32_t incr,
                                   uint64_t flags)
{
        uint64_t src = (params->src + (addr >> 12) * 8);


        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 and return 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_update_level - update a single level in the hierarchy
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 * @parent: parent directory
 *
 * Makes sure all entries in @parent are up to date.
 * Returns 0 for success, error for failure.
 */
static int amdgpu_vm_update_level(struct amdgpu_device *adev,
                                  struct amdgpu_vm *vm,
                                  struct amdgpu_vm_pt *parent,
                                  unsigned level)
{
        struct amdgpu_bo *shadow;
        struct amdgpu_ring *ring;
        uint64_t pd_addr, shadow_addr;
        uint32_t incr = amdgpu_vm_bo_size(adev, level + 1);
        uint64_t last_pde = ~0, last_pt = ~0, last_shadow = ~0;
        unsigned count = 0, pt_idx, ndw;
        struct amdgpu_job *job;
        struct amdgpu_pte_update_params params;
        struct dma_fence *fence = NULL;

        int r;

        if (!parent->entries)
                return 0;
        ring = container_of(vm->entity.sched, struct amdgpu_ring, sched);

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

        /* assume the worst case */
        ndw += parent->last_entry_used * 6;

        pd_addr = amdgpu_bo_gpu_offset(parent->bo);

        shadow = parent->bo->shadow;
        if (shadow) {
                r = amdgpu_ttm_bind(&shadow->tbo, &shadow->tbo.mem);
                if (r)
                        return r;
                shadow_addr = amdgpu_bo_gpu_offset(shadow);
                ndw *= 2;
        } else {
                shadow_addr = 0;
        }

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

        memset(&params, 0, sizeof(params));
        params.adev = adev;
        params.ib = &job->ibs[0];

        /* walk over the address space and update the directory */
        for (pt_idx = 0; pt_idx <= parent->last_entry_used; ++pt_idx) {
                struct amdgpu_bo *bo = parent->entries[pt_idx].bo;
                uint64_t pde, pt;

                if (bo == NULL)
                        continue;

                if (bo->shadow) {
                        struct amdgpu_bo *pt_shadow = bo->shadow;

                        r = amdgpu_ttm_bind(&pt_shadow->tbo,
                                            &pt_shadow->tbo.mem);
                        if (r)
                                return r;
                }

                pt = amdgpu_bo_gpu_offset(bo);
                if (parent->entries[pt_idx].addr == pt)
                        continue;

                parent->entries[pt_idx].addr = pt;

                pde = pd_addr + pt_idx * 8;
                if (((last_pde + 8 * count) != pde) ||
                    ((last_pt + incr * count) != pt) ||
                    (count == AMDGPU_VM_MAX_UPDATE_SIZE)) {

                        if (count) {
                                uint64_t pt_addr =
                                        amdgpu_vm_adjust_mc_addr(adev, last_pt);

                                if (shadow)
                                        amdgpu_vm_do_set_ptes(&params,
                                                              last_shadow,
                                                              pt_addr, count,
                                                              incr,
                                                              AMDGPU_PTE_VALID);

                                amdgpu_vm_do_set_ptes(&params, last_pde,
                                                      pt_addr, count, incr,
                                                      AMDGPU_PTE_VALID);
                        }

                        count = 1;
                        last_pde = pde;
                        last_shadow = shadow_addr + pt_idx * 8;
                        last_pt = pt;
                } else {
                        ++count;
                }
        }

        if (count) {
                uint64_t pt_addr = amdgpu_vm_adjust_mc_addr(adev, last_pt);

                if (vm->root.bo->shadow)
                        amdgpu_vm_do_set_ptes(&params, last_shadow, pt_addr,
                                              count, incr, AMDGPU_PTE_VALID);

                amdgpu_vm_do_set_ptes(&params, last_pde, pt_addr,
                                      count, incr, AMDGPU_PTE_VALID);
        }

        if (params.ib->length_dw == 0) {
                amdgpu_job_free(job);
        } else {
                amdgpu_ring_pad_ib(ring, params.ib);
                amdgpu_sync_resv(adev, &job->sync, parent->bo->tbo.resv,
                                 AMDGPU_FENCE_OWNER_VM);
                if (shadow)
                        amdgpu_sync_resv(adev, &job->sync, shadow->tbo.resv,
                                         AMDGPU_FENCE_OWNER_VM);

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

                amdgpu_bo_fence(parent->bo, fence, true);
                dma_fence_put(vm->last_dir_update);
                vm->last_dir_update = dma_fence_get(fence);
                dma_fence_put(fence);
        }
        /*
         * Recurse into the subdirectories. This recursion is harmless because
         * we only have a maximum of 5 layers.
         */
        for (pt_idx = 0; pt_idx <= parent->last_entry_used; ++pt_idx) {
                struct amdgpu_vm_pt *entry = &parent->entries[pt_idx];

                if (!entry->bo)
                        continue;

                r = amdgpu_vm_update_level(adev, vm, entry, level + 1);
                if (r)
                        return r;
        }

        return 0;

error_free:
        amdgpu_job_free(job);
        return r;
}

/*
 * 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)
{
        return amdgpu_vm_update_level(adev, vm, &vm->root, 0);
}

/**
 * amdgpu_vm_find_pt - find the page table for an address
 *
 * @p: see amdgpu_pte_update_params definition
 * @addr: virtual address in question
 *
 * Find the page table BO for a virtual address, return NULL when none found.
 */
static struct amdgpu_bo *amdgpu_vm_get_pt(struct amdgpu_pte_update_params *p,
                                          uint64_t addr)
{
        struct amdgpu_vm_pt *entry = &p->vm->root;
        unsigned idx, level = p->adev->vm_manager.num_level;

        while (entry->entries) {
                idx = addr >> (amdgpu_vm_block_size * level--);
                idx %= amdgpu_bo_size(entry->bo) / 8;
                entry = &entry->entries[idx];
        }

        if (level)
                return NULL;

        return entry->bo;
}

/**
 * amdgpu_vm_update_ptes - make sure that page tables are valid
 *
 * @params: see amdgpu_pte_update_params definition
 * @vm: requested vm
 * @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.
 */
static void amdgpu_vm_update_ptes(struct amdgpu_pte_update_params *params,
                                  uint64_t start, uint64_t end,
                                  uint64_t dst, uint64_t flags)
{
        const uint64_t mask = AMDGPU_VM_PTE_COUNT - 1;

        uint64_t cur_pe_start, cur_nptes, cur_dst;
        uint64_t addr; /* next GPU address to be updated */
        struct amdgpu_bo *pt;
        unsigned nptes; /* next number of ptes to be updated */
        uint64_t next_pe_start;

        /* initialize the variables */
        addr = start;
        pt = amdgpu_vm_get_pt(params, addr);
        if (!pt) {
                pr_err("PT not found, aborting update_ptes\n");
                return;
        }

        if (params->shadow) {
                if (!pt->shadow)
                        return;
                pt = pt->shadow;
        }
        if ((addr & ~mask) == (end & ~mask))
                nptes = end - addr;
        else
                nptes = AMDGPU_VM_PTE_COUNT - (addr & mask);

        cur_pe_start = amdgpu_bo_gpu_offset(pt);
        cur_pe_start += (addr & mask) * 8;
        cur_nptes = nptes;
        cur_dst = dst;

        /* for next ptb*/
        addr += nptes;
        dst += nptes * AMDGPU_GPU_PAGE_SIZE;

        /* walk over the address space and update the page tables */
        while (addr < end) {
                pt = amdgpu_vm_get_pt(params, addr);
                if (!pt) {
                        pr_err("PT not found, aborting update_ptes\n");
                        return;
                }

                if (params->shadow) {
                        if (!pt->shadow)
                                return;
                        pt = pt->shadow;
                }

                if ((addr & ~mask) == (end & ~mask))
                        nptes = end - addr;
                else
                        nptes = AMDGPU_VM_PTE_COUNT - (addr & mask);

                next_pe_start = amdgpu_bo_gpu_offset(pt);
                next_pe_start += (addr & mask) * 8;

                if ((cur_pe_start + 8 * cur_nptes) == next_pe_start &&
                    ((cur_nptes + nptes) <= AMDGPU_VM_MAX_UPDATE_SIZE)) {
                        /* The next ptb is consecutive to current ptb.
                         * Don't call the update function now.
                         * Will update two ptbs together in future.
                        */
                        cur_nptes += nptes;
                } else {
                        params->func(params, cur_pe_start, cur_dst, cur_nptes,
                                     AMDGPU_GPU_PAGE_SIZE, flags);

                        cur_pe_start = next_pe_start;
                        cur_nptes = nptes;
                        cur_dst = dst;
                }

                /* for next ptb*/
                addr += nptes;
                dst += nptes * AMDGPU_GPU_PAGE_SIZE;
        }

        params->func(params, cur_pe_start, cur_dst, cur_nptes,
                     AMDGPU_GPU_PAGE_SIZE, flags);
}

/*
 * amdgpu_vm_frag_ptes - add fragment information to PTEs
 *
 * @params: see amdgpu_pte_update_params definition
 * @vm: requested vm
 * @start: first PTE to handle
 * @end: last PTE to handle
 * @dst: addr those PTEs should point to
 * @flags: hw mapping flags
 */
static void amdgpu_vm_frag_ptes(struct amdgpu_pte_update_params *params,
                                uint64_t start, uint64_t end,
                                uint64_t dst, uint64_t flags)
{
        /**
         * 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.
         */

        /* SI and newer are optimized for 64KB */
        uint64_t frag_flags = AMDGPU_PTE_FRAG(AMDGPU_LOG2_PAGES_PER_FRAG);
        uint64_t frag_align = 1 << AMDGPU_LOG2_PAGES_PER_FRAG;

        uint64_t frag_start = ALIGN(start, frag_align);
        uint64_t frag_end = end & ~(frag_align - 1);

        /* system pages are non continuously */
        if (params->src || !(flags & AMDGPU_PTE_VALID) ||
            (frag_start >= frag_end)) {

                amdgpu_vm_update_ptes(params, start, end, dst, flags);
                return;
        }

        /* handle the 4K area at the beginning */
        if (start != frag_start) {
                amdgpu_vm_update_ptes(params, start, frag_start,
                                      dst, flags);
                dst += (frag_start - start) * AMDGPU_GPU_PAGE_SIZE;
        }

        /* handle the area in the middle */
        amdgpu_vm_update_ptes(params, frag_start, frag_end, dst,
                              flags | frag_flags);

        /* handle the 4K area at the end */
        if (frag_end != end) {
                dst += (frag_end - frag_start) * AMDGPU_GPU_PAGE_SIZE;
                amdgpu_vm_update_ptes(params, frag_end, end, dst, flags);
        }
}

/**
 * amdgpu_vm_bo_update_mapping - update a mapping in the vm page table
 *
 * @adev: amdgpu_device pointer
 * @exclusive: fence we need to sync to
 * @src: address where to copy page table entries from
 * @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,
                                       uint64_t src,
                                       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;
        params.src = src;

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

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

        nptes = last - start + 1;

        /*
         * reserve space for one command every (1 << BLOCK_SIZE)
         *  entries or 2k dwords (whatever is smaller)
         */
        ncmds = (nptes >> min(amdgpu_vm_block_size, 11)) + 1;

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

        if (src) {
                /* only copy commands needed */
                ndw += ncmds * 7;

                params.func = amdgpu_vm_do_copy_ptes;

        } else if (pages_addr) {
                /* copy commands needed */
                ndw += ncmds * 7;

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

                params.func = amdgpu_vm_do_copy_ptes;

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

                /* two extra commands for begin/end of fragment */
                ndw += 2 * 10;

                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 (!src && 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);
        if (r)
                goto error_free;

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

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

        params.shadow = true;
        amdgpu_vm_frag_ptes(&params, start, last + 1, addr, flags);
        params.shadow = false;
        amdgpu_vm_frag_ptes(&params, start, last + 1, addr, flags);

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

        amdgpu_bo_fence(vm->root.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
 * @gtt_flags: flags as they are used for GTT
 * @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,
                                      uint64_t gtt_flags,
                                      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)
{
        uint64_t pfn, src = 0, 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);

        trace_amdgpu_vm_bo_update(mapping);

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

        do {
                uint64_t max_entries;
                uint64_t addr, last;

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

                if (pages_addr) {
                        if (flags == gtt_flags)
                                src = adev->gart.table_addr +
                                        (addr >> AMDGPU_GPU_PAGE_SHIFT) * 8;
                        else
                                max_entries = min(max_entries, 16ull * 1024ull);
                        addr = 0;
                } 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,
                                                src, pages_addr, vm,
                                                start, last, flags, addr,
                                                fence);
                if (r)
                        return r;

                pfn += last - start + 1;
                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_vm *vm = bo_va->vm;
        struct amdgpu_bo_va_mapping *mapping;
        dma_addr_t *pages_addr = NULL;
        uint64_t gtt_flags, flags;
        struct ttm_mem_reg *mem;
        struct drm_mm_node *nodes;
        struct dma_fence *exclusive;
        int r;

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

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

        if (bo_va->bo) {
                flags = amdgpu_ttm_tt_pte_flags(adev, bo_va->bo->tbo.ttm, mem);
                gtt_flags = (amdgpu_ttm_is_bound(bo_va->bo->tbo.ttm) &&
                        adev == amdgpu_ttm_adev(bo_va->bo->tbo.bdev)) ?
                        flags : 0;
        } else {
                flags = 0x0;
                gtt_flags = ~0x0;
        }

        spin_lock(&vm->status_lock);
        if (!list_empty(&bo_va->vm_status))
                list_splice_init(&bo_va->valids, &bo_va->invalids);
        spin_unlock(&vm->status_lock);

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

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

                list_for_each_entry(mapping, &bo_va->invalids, list)
                        trace_amdgpu_vm_bo_mapping(mapping);
        }

        spin_lock(&vm->status_lock);
        list_splice_init(&bo_va->invalids, &bo_va->valids);
        list_del_init(&bo_va->vm_status);
        if (clear)
                list_add(&bo_va->vm_status, &vm->cleared);
        spin_unlock(&vm->status_lock);

        return 0;
}

/**
 * amdgpu_vm_update_prt_state - update the global PRT state
 */
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->gart.gart_funcs->set_prt(adev, enable);
        spin_unlock_irqrestore(&adev->vm_manager.prt_lock, flags);
}

/**
 * amdgpu_vm_prt_get - add a PRT user
 */
static void amdgpu_vm_prt_get(struct amdgpu_device *adev)
{
        if (!adev->gart.gart_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
 */
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
 */
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
 */
static void amdgpu_vm_add_prt_cb(struct amdgpu_device *adev,
                                 struct dma_fence *fence)
{
        struct amdgpu_prt_cb *cb;

        if (!adev->gart.gart_funcs->set_prt)
                return;

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

                amdgpu_vm_prt_put(cb->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.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.
 * Returns 0 for success.
 *
 * PTs have to be reserved and mutex must be locked!
 */
int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
                          struct amdgpu_vm *vm,
                          struct dma_fence **fence)
{
        struct amdgpu_bo_va_mapping *mapping;
        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);

                r = amdgpu_vm_bo_split_mapping(adev, NULL, 0, NULL, vm, mapping,
                                               0, 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_clear_invalids - clear invalidated BOs in the PT
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * Make sure all invalidated BOs are cleared in the PT.
 * Returns 0 for success.
 *
 * PTs have to be reserved and mutex must be locked!
 */
int amdgpu_vm_clear_invalids(struct amdgpu_device *adev,
                             struct amdgpu_vm *vm, struct amdgpu_sync *sync)
{
        struct amdgpu_bo_va *bo_va = NULL;
        int r = 0;

        spin_lock(&vm->status_lock);
        while (!list_empty(&vm->invalidated)) {
                bo_va = list_first_entry(&vm->invalidated,
                        struct amdgpu_bo_va, vm_status);
                spin_unlock(&vm->status_lock);

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

                spin_lock(&vm->status_lock);
        }
        spin_unlock(&vm->status_lock);

        if (bo_va)
                r = amdgpu_sync_fence(adev, sync, bo_va->last_pt_update);

        return r;
}

/**
 * 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;
        }
        bo_va->vm = vm;
        bo_va->bo = bo;
        bo_va->ref_count = 1;
        INIT_LIST_HEAD(&bo_va->bo_list);
        INIT_LIST_HEAD(&bo_va->valids);
        INIT_LIST_HEAD(&bo_va->invalids);
        INIT_LIST_HEAD(&bo_va->vm_status);

        if (bo)
                list_add_tail(&bo_va->bo_list, &bo->va);

        return bo_va;
}

/**
 * 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
 * @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_vm *vm = bo_va->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_va->bo && offset + size > amdgpu_bo_size(bo_va->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_va->bo, saddr, eaddr,
                        tmp->start, tmp->last + 1);
                return -EINVAL;
        }

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

        INIT_LIST_HEAD(&mapping->list);
        mapping->start = saddr;
        mapping->last = eaddr;
        mapping->offset = offset;
        mapping->flags = flags;

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

        if (flags & AMDGPU_PTE_PRT)
                amdgpu_vm_prt_get(adev);

        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
 * @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_vm *vm = bo_va->vm;
        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_va->bo && offset + size > amdgpu_bo_size(bo_va->bo)))
                return -EINVAL;

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

        r = amdgpu_vm_bo_clear_mappings(adev, bo_va->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;

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

        if (flags & AMDGPU_PTE_PRT)
                amdgpu_vm_prt_get(adev);

        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->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);
        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;
        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;
                        list_add(&before->list, &tmp->list);
                }

                /* 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;
                        list_add(&after->list, &tmp->list);
                }

                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;

                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_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_vm *vm = bo_va->vm;

        list_del(&bo_va->bo_list);

        spin_lock(&vm->status_lock);
        list_del(&bo_va->vm_status);
        spin_unlock(&vm->status_lock);

        list_for_each_entry_safe(mapping, next, &bo_va->valids, list) {
                list_del(&mapping->list);
                amdgpu_vm_it_remove(mapping, &vm->va);
                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
 * @vm: requested vm
 * @bo: amdgpu buffer object
 *
 * Mark @bo as invalid.
 */
void amdgpu_vm_bo_invalidate(struct amdgpu_device *adev,
                             struct amdgpu_bo *bo)
{
        struct amdgpu_bo_va *bo_va;

        list_for_each_entry(bo_va, &bo->va, bo_list) {
                spin_lock(&bo_va->vm->status_lock);
                if (list_empty(&bo_va->vm_status))
                        list_add(&bo_va->vm_status, &bo_va->vm->invalidated);
                spin_unlock(&bo_va->vm->status_lock);
        }
}

/**
 * amdgpu_vm_init - initialize a vm instance
 *
 * @adev: amdgpu_device pointer
 * @vm: requested vm
 *
 * Init @vm fields.
 */
int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
{
        const unsigned align = min(AMDGPU_VM_PTB_ALIGN_SIZE,
                AMDGPU_VM_PTE_COUNT * 8);
        unsigned ring_instance;
        struct amdgpu_ring *ring;
        struct amd_sched_rq *rq;
        int i, r;

        for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
                vm->ids[i] = NULL;
        vm->va = RB_ROOT;
        vm->client_id = atomic64_inc_return(&adev->vm_manager.client_counter);
        spin_lock_init(&vm->status_lock);
        INIT_LIST_HEAD(&vm->invalidated);
        INIT_LIST_HEAD(&vm->cleared);
        INIT_LIST_HEAD(&vm->freed);

        /* create scheduler entity for page table updates */

        ring_instance = atomic_inc_return(&adev->vm_manager.vm_pte_next_ring);
        ring_instance %= adev->vm_manager.vm_pte_num_rings;
        ring = adev->vm_manager.vm_pte_rings[ring_instance];
        rq = &ring->sched.sched_rq[AMD_SCHED_PRIORITY_KERNEL];
        r = amd_sched_entity_init(&ring->sched, &vm->entity,
                                  rq, amdgpu_sched_jobs);
        if (r)
                return r;

        vm->last_dir_update = NULL;

        r = amdgpu_bo_create(adev, amdgpu_vm_bo_size(adev, 0), align, true,
                             AMDGPU_GEM_DOMAIN_VRAM,
                             AMDGPU_GEM_CREATE_NO_CPU_ACCESS |
                             AMDGPU_GEM_CREATE_SHADOW |
                             AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS |
                             AMDGPU_GEM_CREATE_VRAM_CLEARED,
                             NULL, NULL, &vm->root.bo);
        if (r)
                goto error_free_sched_entity;

        r = amdgpu_bo_reserve(vm->root.bo, false);
        if (r)
                goto error_free_root;

        vm->last_eviction_counter = atomic64_read(&adev->num_evictions);
        amdgpu_bo_unreserve(vm->root.bo);

        return 0;

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

error_free_sched_entity:
        amd_sched_entity_fini(&ring->sched, &vm->entity);

        return r;
}

/**
 * amdgpu_vm_free_levels - free PD/PT levels
 *
 * @level: PD/PT starting level to free
 *
 * Free the page directory or page table level and all sub levels.
 */
static void amdgpu_vm_free_levels(struct amdgpu_vm_pt *level)
{
        unsigned i;

        if (level->bo) {
                amdgpu_bo_unref(&level->bo->shadow);
                amdgpu_bo_unref(&level->bo);
        }

        if (level->entries)
                for (i = 0; i <= level->last_entry_used; i++)
                        amdgpu_vm_free_levels(&level->entries[i]);

        drm_free_large(level->entries);
}

/**
 * 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->gart.gart_funcs->set_prt;

        amd_sched_entity_fini(vm->entity.sched, &vm->entity);

        if (!RB_EMPTY_ROOT(&vm->va)) {
                dev_err(adev->dev, "still active bo inside vm\n");
        }
        rbtree_postorder_for_each_entry_safe(mapping, tmp, &vm->va, rb) {
                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);
        }

        amdgpu_vm_free_levels(&vm->root);
        dma_fence_put(vm->last_dir_update);
}

/**
 * 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;

        INIT_LIST_HEAD(&adev->vm_manager.ids_lru);

        /* skip over VMID 0, since it is the system VM */
        for (i = 1; i < adev->vm_manager.num_ids; ++i) {
                amdgpu_vm_reset_id(adev, i);
                amdgpu_sync_create(&adev->vm_manager.ids[i].active);
                list_add_tail(&adev->vm_manager.ids[i].list,
                              &adev->vm_manager.ids_lru);
        }

        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;

        atomic_set(&adev->vm_manager.vm_pte_next_ring, 0);
        atomic64_set(&adev->vm_manager.client_counter, 0);
        spin_lock_init(&adev->vm_manager.prt_lock);
        atomic_set(&adev->vm_manager.num_prt_users, 0);
}

/**
 * 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)
{
        unsigned i;

        for (i = 0; i < AMDGPU_NUM_VM; ++i) {
                struct amdgpu_vm_id *id = &adev->vm_manager.ids[i];

                dma_fence_put(adev->vm_manager.ids[i].first);
                amdgpu_sync_free(&adev->vm_manager.ids[i].active);
                dma_fence_put(id->flushed_updates);
                dma_fence_put(id->last_flush);
        }
}