// SPDX-License-Identifier: MIT
/*
 * Copyright 2014-2018 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
#include <linux/dma-buf.h>
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <drm/ttm/ttm_tt.h>

#include <drm/drm_exec.h>

#include "amdgpu_object.h"
#include "amdgpu_gem.h"
#include "amdgpu_vm.h"
#include "amdgpu_hmm.h"
#include "amdgpu_amdkfd.h"
#include "amdgpu_dma_buf.h"
#include <uapi/linux/kfd_ioctl.h>
#include "amdgpu_xgmi.h"
#include "kfd_priv.h"
#include "kfd_smi_events.h"

/* Userptr restore delay, just long enough to allow consecutive VM
 * changes to accumulate
 */
#define AMDGPU_USERPTR_RESTORE_DELAY_MS 1
#define AMDGPU_RESERVE_MEM_LIMIT                        (3UL << 29)

/*
 * Align VRAM availability to 2MB to avoid fragmentation caused by 4K allocations in the tail 2MB
 * BO chunk
 */
#define VRAM_AVAILABLITY_ALIGN (1 << 21)

/* Impose limit on how much memory KFD can use */
static struct {
        uint64_t max_system_mem_limit;
        uint64_t max_ttm_mem_limit;
        int64_t system_mem_used;
        int64_t ttm_mem_used;
        spinlock_t mem_limit_lock;
} kfd_mem_limit;

static const char * const domain_bit_to_string[] = {
                "CPU",
                "GTT",
                "VRAM",
                "GDS",
                "GWS",
                "OA"
};

#define domain_string(domain) domain_bit_to_string[ffs(domain)-1]

static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work);

static bool kfd_mem_is_attached(struct amdgpu_vm *avm,
                struct kgd_mem *mem)
{
        struct kfd_mem_attachment *entry;

        list_for_each_entry(entry, &mem->attachments, list)
                if (entry->bo_va->base.vm == avm)
                        return true;

        return false;
}

/**
 * reuse_dmamap() - Check whether adev can share the original
 * userptr BO
 *
 * If both adev and bo_adev are in direct mapping or
 * in the same iommu group, they can share the original BO.
 *
 * @adev: Device to which can or cannot share the original BO
 * @bo_adev: Device to which allocated BO belongs to
 *
 * Return: returns true if adev can share original userptr BO,
 * false otherwise.
 */
static bool reuse_dmamap(struct amdgpu_device *adev, struct amdgpu_device *bo_adev)
{
        return (adev->ram_is_direct_mapped && bo_adev->ram_is_direct_mapped) ||
                        (adev->dev->iommu_group == bo_adev->dev->iommu_group);
}

/* Set memory usage limits. Current, limits are
 *  System (TTM + userptr) memory - 15/16th System RAM
 *  TTM memory - 3/8th System RAM
 */
void amdgpu_amdkfd_gpuvm_init_mem_limits(void)
{
        struct sysinfo si;
        uint64_t mem;

        if (kfd_mem_limit.max_system_mem_limit)
                return;

        si_meminfo(&si);
        mem = si.totalram - si.totalhigh;
        mem *= si.mem_unit;

        spin_lock_init(&kfd_mem_limit.mem_limit_lock);
        kfd_mem_limit.max_system_mem_limit = mem - (mem >> 6);
        if (kfd_mem_limit.max_system_mem_limit < 2 * AMDGPU_RESERVE_MEM_LIMIT)
                kfd_mem_limit.max_system_mem_limit >>= 1;
        else
                kfd_mem_limit.max_system_mem_limit -= AMDGPU_RESERVE_MEM_LIMIT;

        kfd_mem_limit.max_ttm_mem_limit = ttm_tt_pages_limit() << PAGE_SHIFT;
        pr_debug("Kernel memory limit %lluM, TTM limit %lluM\n",
                (kfd_mem_limit.max_system_mem_limit >> 20),
                (kfd_mem_limit.max_ttm_mem_limit >> 20));
}

void amdgpu_amdkfd_reserve_system_mem(uint64_t size)
{
        kfd_mem_limit.system_mem_used += size;
}

/* Estimate page table size needed to represent a given memory size
 *
 * With 4KB pages, we need one 8 byte PTE for each 4KB of memory
 * (factor 512, >> 9). With 2MB pages, we need one 8 byte PTE for 2MB
 * of memory (factor 256K, >> 18). ROCm user mode tries to optimize
 * for 2MB pages for TLB efficiency. However, small allocations and
 * fragmented system memory still need some 4KB pages. We choose a
 * compromise that should work in most cases without reserving too
 * much memory for page tables unnecessarily (factor 16K, >> 14).
 */

#define ESTIMATE_PT_SIZE(mem_size) max(((mem_size) >> 14), AMDGPU_VM_RESERVED_VRAM)

/**
 * amdgpu_amdkfd_reserve_mem_limit() - Decrease available memory by size
 * of buffer.
 *
 * @adev: Device to which allocated BO belongs to
 * @size: Size of buffer, in bytes, encapsulated by B0. This should be
 * equivalent to amdgpu_bo_size(BO)
 * @alloc_flag: Flag used in allocating a BO as noted above
 * @xcp_id: xcp_id is used to get xcp from xcp manager, one xcp is
 * managed as one compute node in driver for app
 *
 * Return:
 *      returns -ENOMEM in case of error, ZERO otherwise
 */
int amdgpu_amdkfd_reserve_mem_limit(struct amdgpu_device *adev,
                uint64_t size, u32 alloc_flag, int8_t xcp_id)
{
        uint64_t reserved_for_pt =
                ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size);
        struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
        uint64_t reserved_for_ras = (con ? con->reserved_pages_in_bytes : 0);
        size_t system_mem_needed, ttm_mem_needed, vram_needed;
        int ret = 0;
        uint64_t vram_size = 0;

        system_mem_needed = 0;
        ttm_mem_needed = 0;
        vram_needed = 0;
        if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_GTT) {
                system_mem_needed = size;
                ttm_mem_needed = size;
        } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {
                /*
                 * Conservatively round up the allocation requirement to 2 MB
                 * to avoid fragmentation caused by 4K allocations in the tail
                 * 2M BO chunk.
                 */
                vram_needed = size;
                /*
                 * For GFX 9.4.3, get the VRAM size from XCP structs
                 */
                if (WARN_ONCE(xcp_id < 0, "invalid XCP ID %d", xcp_id))
                        return -EINVAL;

                vram_size = KFD_XCP_MEMORY_SIZE(adev, xcp_id);
                if (adev->apu_prefer_gtt) {
                        system_mem_needed = size;
                        ttm_mem_needed = size;
                }
        } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
                system_mem_needed = size;
        } else if (!(alloc_flag &
                                (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
                                 KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP))) {
                pr_err("%s: Invalid BO type %#x\n", __func__, alloc_flag);
                return -ENOMEM;
        }

        spin_lock(&kfd_mem_limit.mem_limit_lock);

        if (kfd_mem_limit.system_mem_used + system_mem_needed >
            kfd_mem_limit.max_system_mem_limit) {
                pr_debug("Set no_system_mem_limit=1 if using shared memory\n");
                if (!no_system_mem_limit) {
                        ret = -ENOMEM;
                        goto release;
                }
        }

        if (kfd_mem_limit.ttm_mem_used + ttm_mem_needed >
                kfd_mem_limit.max_ttm_mem_limit) {
                ret = -ENOMEM;
                goto release;
        }

        /*if is_app_apu is false and apu_prefer_gtt is true, it is an APU with
         * carve out < gtt. In that case, VRAM allocation will go to gtt domain, skip
         * VRAM check since ttm_mem_limit check already cover this allocation
         */

        if (adev && xcp_id >= 0 && (!adev->apu_prefer_gtt || adev->gmc.is_app_apu)) {
                uint64_t vram_available =
                        vram_size - reserved_for_pt - reserved_for_ras -
                        atomic64_read(&adev->vram_pin_size);
                if (adev->kfd.vram_used[xcp_id] + vram_needed > vram_available) {
                        ret = -ENOMEM;
                        goto release;
                }
        }

        /* Update memory accounting by decreasing available system
         * memory, TTM memory and GPU memory as computed above
         */
        WARN_ONCE(vram_needed && !adev,
                  "adev reference can't be null when vram is used");
        if (adev && xcp_id >= 0) {
                adev->kfd.vram_used[xcp_id] += vram_needed;
                adev->kfd.vram_used_aligned[xcp_id] +=
                                adev->apu_prefer_gtt ?
                                vram_needed :
                                ALIGN(vram_needed, VRAM_AVAILABLITY_ALIGN);
        }
        kfd_mem_limit.system_mem_used += system_mem_needed;
        kfd_mem_limit.ttm_mem_used += ttm_mem_needed;

release:
        spin_unlock(&kfd_mem_limit.mem_limit_lock);
        return ret;
}

void amdgpu_amdkfd_unreserve_mem_limit(struct amdgpu_device *adev,
                uint64_t size, u32 alloc_flag, int8_t xcp_id)
{
        spin_lock(&kfd_mem_limit.mem_limit_lock);

        if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_GTT) {
                kfd_mem_limit.system_mem_used -= size;
                kfd_mem_limit.ttm_mem_used -= size;
        } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {
                WARN_ONCE(!adev,
                          "adev reference can't be null when alloc mem flags vram is set");
                if (WARN_ONCE(xcp_id < 0, "invalid XCP ID %d", xcp_id))
                        goto release;

                if (adev) {
                        adev->kfd.vram_used[xcp_id] -= size;
                        if (adev->apu_prefer_gtt) {
                                adev->kfd.vram_used_aligned[xcp_id] -= size;
                                kfd_mem_limit.system_mem_used -= size;
                                kfd_mem_limit.ttm_mem_used -= size;
                        } else {
                                adev->kfd.vram_used_aligned[xcp_id] -=
                                        ALIGN(size, VRAM_AVAILABLITY_ALIGN);
                        }
                }
        } else if (alloc_flag & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
                kfd_mem_limit.system_mem_used -= size;
        } else if (!(alloc_flag &
                                (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
                                 KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP))) {
                pr_err("%s: Invalid BO type %#x\n", __func__, alloc_flag);
                goto release;
        }
        WARN_ONCE(adev && xcp_id >= 0 && adev->kfd.vram_used[xcp_id] < 0,
                  "KFD VRAM memory accounting unbalanced for xcp: %d", xcp_id);
        WARN_ONCE(kfd_mem_limit.ttm_mem_used < 0,
                  "KFD TTM memory accounting unbalanced");
        WARN_ONCE(kfd_mem_limit.system_mem_used < 0,
                  "KFD system memory accounting unbalanced");

release:
        spin_unlock(&kfd_mem_limit.mem_limit_lock);
}

void amdgpu_amdkfd_release_notify(struct amdgpu_bo *bo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        u32 alloc_flags = bo->kfd_bo->alloc_flags;
        u64 size = amdgpu_bo_size(bo);

        amdgpu_amdkfd_unreserve_mem_limit(adev, size, alloc_flags,
                                          bo->xcp_id);

        kfree(bo->kfd_bo);
}

/**
 * create_dmamap_sg_bo() - Creates a amdgpu_bo object to reflect information
 * about USERPTR or DOOREBELL or MMIO BO.
 *
 * @adev: Device for which dmamap BO is being created
 * @mem: BO of peer device that is being DMA mapped. Provides parameters
 *       in building the dmamap BO
 * @bo_out: Output parameter updated with handle of dmamap BO
 */
static int
create_dmamap_sg_bo(struct amdgpu_device *adev,
                 struct kgd_mem *mem, struct amdgpu_bo **bo_out)
{
        struct drm_gem_object *gem_obj;
        int ret;
        uint64_t flags = 0;

        ret = amdgpu_bo_reserve(mem->bo, false);
        if (ret)
                return ret;

        if (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR)
                flags |= mem->bo->flags & (AMDGPU_GEM_CREATE_COHERENT |
                                        AMDGPU_GEM_CREATE_UNCACHED);

        ret = amdgpu_gem_object_create(adev, mem->bo->tbo.base.size, 1,
                        AMDGPU_GEM_DOMAIN_CPU, AMDGPU_GEM_CREATE_PREEMPTIBLE | flags,
                        ttm_bo_type_sg, mem->bo->tbo.base.resv, &gem_obj, 0);

        amdgpu_bo_unreserve(mem->bo);

        if (ret) {
                pr_err("Error in creating DMA mappable SG BO on domain: %d\n", ret);
                return -EINVAL;
        }

        *bo_out = gem_to_amdgpu_bo(gem_obj);
        (*bo_out)->parent = amdgpu_bo_ref(mem->bo);
        return ret;
}

/* amdgpu_amdkfd_remove_eviction_fence - Removes eviction fence from BO's
 *  reservation object.
 *
 * @bo: [IN] Remove eviction fence(s) from this BO
 * @ef: [IN] This eviction fence is removed if it
 *  is present in the shared list.
 *
 * NOTE: Must be called with BO reserved i.e. bo->tbo.resv->lock held.
 */
static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
                                        struct amdgpu_amdkfd_fence *ef)
{
        struct dma_fence *replacement;

        if (!ef)
                return -EINVAL;

        /* TODO: Instead of block before we should use the fence of the page
         * table update and TLB flush here directly.
         */
        replacement = dma_fence_get_stub();
        dma_resv_replace_fences(bo->tbo.base.resv, ef->base.context,
                                replacement, DMA_RESV_USAGE_BOOKKEEP);
        dma_fence_put(replacement);
        return 0;
}

/**
 * amdgpu_amdkfd_remove_all_eviction_fences - Remove all eviction fences
 * @bo: the BO where to remove the evictions fences from.
 *
 * This functions should only be used on release when all references to the BO
 * are already dropped. We remove the eviction fence from the private copy of
 * the dma_resv object here since that is what is used during release to
 * determine of the BO is idle or not.
 */
void amdgpu_amdkfd_remove_all_eviction_fences(struct amdgpu_bo *bo)
{
        struct dma_resv *resv = &bo->tbo.base._resv;
        struct dma_fence *fence, *stub;
        struct dma_resv_iter cursor;

        dma_resv_assert_held(resv);

        stub = dma_fence_get_stub();
        dma_resv_for_each_fence(&cursor, resv, DMA_RESV_USAGE_BOOKKEEP, fence) {
                if (!to_amdgpu_amdkfd_fence(fence))
                        continue;

                dma_resv_replace_fences(resv, fence->context, stub,
                                        DMA_RESV_USAGE_BOOKKEEP);
        }
        dma_fence_put(stub);
}

static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
                                     bool wait)
{
        struct ttm_operation_ctx ctx = { false, false };
        int ret;

        if (WARN(amdgpu_ttm_tt_get_usermm(bo->tbo.ttm),
                 "Called with userptr BO"))
                return -EINVAL;

        /* bo has been pinned, not need validate it */
        if (bo->tbo.pin_count)
                return 0;

        amdgpu_bo_placement_from_domain(bo, domain);

        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
        if (ret)
                goto validate_fail;
        if (wait)
                amdgpu_bo_sync_wait(bo, AMDGPU_FENCE_OWNER_KFD, false);

validate_fail:
        return ret;
}

int amdgpu_amdkfd_bo_validate_and_fence(struct amdgpu_bo *bo,
                                        uint32_t domain,
                                        struct dma_fence *fence)
{
        int ret = amdgpu_bo_reserve(bo, false);

        if (ret)
                return ret;

        ret = amdgpu_amdkfd_bo_validate(bo, domain, true);
        if (ret)
                goto unreserve_out;

        ret = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
        if (ret)
                goto unreserve_out;

        dma_resv_add_fence(bo->tbo.base.resv, fence,
                           DMA_RESV_USAGE_BOOKKEEP);

unreserve_out:
        amdgpu_bo_unreserve(bo);

        return ret;
}

static int amdgpu_amdkfd_validate_vm_bo(void *_unused, struct amdgpu_bo *bo)
{
        return amdgpu_amdkfd_bo_validate(bo, bo->allowed_domains, false);
}

/* vm_validate_pt_pd_bos - Validate page table and directory BOs
 *
 * Page directories are not updated here because huge page handling
 * during page table updates can invalidate page directory entries
 * again. Page directories are only updated after updating page
 * tables.
 */
static int vm_validate_pt_pd_bos(struct amdgpu_vm *vm,
                                 struct ww_acquire_ctx *ticket)
{
        struct amdgpu_bo *pd = vm->root.bo;
        struct amdgpu_device *adev = amdgpu_ttm_adev(pd->tbo.bdev);
        int ret;

        ret = amdgpu_vm_validate(adev, vm, ticket,
                                 amdgpu_amdkfd_validate_vm_bo, NULL);
        if (ret) {
                pr_err("failed to validate PT BOs\n");
                return ret;
        }

        vm->pd_phys_addr = amdgpu_gmc_pd_addr(vm->root.bo);

        return 0;
}

static int vm_update_pds(struct amdgpu_vm *vm, struct amdgpu_sync *sync)
{
        struct amdgpu_bo *pd = vm->root.bo;
        struct amdgpu_device *adev = amdgpu_ttm_adev(pd->tbo.bdev);
        int ret;

        ret = amdgpu_vm_update_pdes(adev, vm, false);
        if (ret)
                return ret;

        return amdgpu_sync_fence(sync, vm->last_update, GFP_KERNEL);
}

static uint64_t get_pte_flags(struct amdgpu_device *adev, struct amdgpu_vm *vm,
                              struct kgd_mem *mem)
{
        uint32_t mapping_flags = AMDGPU_VM_PAGE_READABLE |
                                 AMDGPU_VM_MTYPE_DEFAULT;

        if (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE)
                mapping_flags |= AMDGPU_VM_PAGE_WRITEABLE;
        if (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_EXECUTABLE)
                mapping_flags |= AMDGPU_VM_PAGE_EXECUTABLE;

        return mapping_flags;
}

/**
 * create_sg_table() - Create an sg_table for a contiguous DMA addr range
 * @addr: The starting address to point to
 * @size: Size of memory area in bytes being pointed to
 *
 * Allocates an instance of sg_table and initializes it to point to memory
 * area specified by input parameters. The address used to build is assumed
 * to be DMA mapped, if needed.
 *
 * DOORBELL or MMIO BOs use only one scatterlist node in their sg_table
 * because they are physically contiguous.
 *
 * Return: Initialized instance of SG Table or NULL
 */
static struct sg_table *create_sg_table(uint64_t addr, uint32_t size)
{
        struct sg_table *sg = kmalloc_obj(*sg);

        if (!sg)
                return NULL;
        if (sg_alloc_table(sg, 1, GFP_KERNEL)) {
                kfree(sg);
                return NULL;
        }
        sg_dma_address(sg->sgl) = addr;
        sg->sgl->length = size;
#ifdef CONFIG_NEED_SG_DMA_LENGTH
        sg->sgl->dma_length = size;
#endif
        return sg;
}

static int
kfd_mem_dmamap_userptr(struct kgd_mem *mem,
                       struct kfd_mem_attachment *attachment)
{
        enum dma_data_direction direction =
                mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
                DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
        struct ttm_operation_ctx ctx = {.interruptible = true};
        struct amdgpu_bo *bo = attachment->bo_va->base.bo;
        struct amdgpu_device *adev = attachment->adev;
        struct ttm_tt *src_ttm = mem->bo->tbo.ttm;
        struct ttm_tt *ttm = bo->tbo.ttm;
        int ret;

        if (WARN_ON(ttm->num_pages != src_ttm->num_pages))
                return -EINVAL;

        ttm->sg = kmalloc_obj(*ttm->sg);
        if (unlikely(!ttm->sg))
                return -ENOMEM;

        /* Same sequence as in amdgpu_ttm_tt_pin_userptr */
        ret = sg_alloc_table_from_pages(ttm->sg, src_ttm->pages,
                                        ttm->num_pages, 0,
                                        (u64)ttm->num_pages << PAGE_SHIFT,
                                        GFP_KERNEL);
        if (unlikely(ret))
                goto free_sg;

        ret = dma_map_sgtable(adev->dev, ttm->sg, direction, 0);
        if (unlikely(ret))
                goto release_sg;

        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
        if (ret)
                goto unmap_sg;

        return 0;

unmap_sg:
        dma_unmap_sgtable(adev->dev, ttm->sg, direction, 0);
release_sg:
        pr_err("DMA map userptr failed: %d\n", ret);
        sg_free_table(ttm->sg);
free_sg:
        kfree(ttm->sg);
        ttm->sg = NULL;
        return ret;
}

static int
kfd_mem_dmamap_dmabuf(struct kfd_mem_attachment *attachment)
{
        struct ttm_operation_ctx ctx = {.interruptible = true};
        struct amdgpu_bo *bo = attachment->bo_va->base.bo;

        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
        return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
}

/**
 * kfd_mem_dmamap_sg_bo() - Create DMA mapped sg_table to access DOORBELL or MMIO BO
 * @mem: SG BO of the DOORBELL or MMIO resource on the owning device
 * @attachment: Virtual address attachment of the BO on accessing device
 *
 * An access request from the device that owns DOORBELL does not require DMA mapping.
 * This is because the request doesn't go through PCIe root complex i.e. it instead
 * loops back. The need to DMA map arises only when accessing peer device's DOORBELL
 *
 * In contrast, all access requests for MMIO need to be DMA mapped without regard to
 * device ownership. This is because access requests for MMIO go through PCIe root
 * complex.
 *
 * This is accomplished in two steps:
 *   - Obtain DMA mapped address of DOORBELL or MMIO memory that could be used
 *         in updating requesting device's page table
 *   - Signal TTM to mark memory pointed to by requesting device's BO as GPU
 *         accessible. This allows an update of requesting device's page table
 *         with entries associated with DOOREBELL or MMIO memory
 *
 * This method is invoked in the following contexts:
 *   - Mapping of DOORBELL or MMIO BO of same or peer device
 *   - Validating an evicted DOOREBELL or MMIO BO on device seeking access
 *
 * Return: ZERO if successful, NON-ZERO otherwise
 */
static int
kfd_mem_dmamap_sg_bo(struct kgd_mem *mem,
                     struct kfd_mem_attachment *attachment)
{
        struct ttm_operation_ctx ctx = {.interruptible = true};
        struct amdgpu_bo *bo = attachment->bo_va->base.bo;
        struct amdgpu_device *adev = attachment->adev;
        struct ttm_tt *ttm = bo->tbo.ttm;
        enum dma_data_direction dir;
        dma_addr_t dma_addr;
        bool mmio;
        int ret;

        /* Expect SG Table of dmapmap BO to be NULL */
        mmio = (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP);
        if (unlikely(ttm->sg)) {
                pr_err("SG Table of %d BO for peer device is UNEXPECTEDLY NON-NULL", mmio);
                return -EINVAL;
        }

        dir = mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
                        DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
        dma_addr = mem->bo->tbo.sg->sgl->dma_address;
        pr_debug("%d BO size: %d\n", mmio, mem->bo->tbo.sg->sgl->length);
        pr_debug("%d BO address before DMA mapping: %llx\n", mmio, dma_addr);
        dma_addr = dma_map_resource(adev->dev, dma_addr,
                        mem->bo->tbo.sg->sgl->length, dir, DMA_ATTR_SKIP_CPU_SYNC);
        ret = dma_mapping_error(adev->dev, dma_addr);
        if (unlikely(ret))
                return ret;
        pr_debug("%d BO address after DMA mapping: %llx\n", mmio, dma_addr);

        ttm->sg = create_sg_table(dma_addr, mem->bo->tbo.sg->sgl->length);
        if (unlikely(!ttm->sg)) {
                ret = -ENOMEM;
                goto unmap_sg;
        }

        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
        if (unlikely(ret))
                goto free_sg;

        return ret;

free_sg:
        sg_free_table(ttm->sg);
        kfree(ttm->sg);
        ttm->sg = NULL;
unmap_sg:
        dma_unmap_resource(adev->dev, dma_addr, mem->bo->tbo.sg->sgl->length,
                           dir, DMA_ATTR_SKIP_CPU_SYNC);
        return ret;
}

static int
kfd_mem_dmamap_attachment(struct kgd_mem *mem,
                          struct kfd_mem_attachment *attachment)
{
        switch (attachment->type) {
        case KFD_MEM_ATT_SHARED:
                return 0;
        case KFD_MEM_ATT_USERPTR:
                return kfd_mem_dmamap_userptr(mem, attachment);
        case KFD_MEM_ATT_DMABUF:
                return kfd_mem_dmamap_dmabuf(attachment);
        case KFD_MEM_ATT_SG:
                return kfd_mem_dmamap_sg_bo(mem, attachment);
        default:
                WARN_ON_ONCE(1);
        }
        return -EINVAL;
}

static void
kfd_mem_dmaunmap_userptr(struct kgd_mem *mem,
                         struct kfd_mem_attachment *attachment)
{
        enum dma_data_direction direction =
                mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
                DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
        struct ttm_operation_ctx ctx = {.interruptible = false};
        struct amdgpu_bo *bo = attachment->bo_va->base.bo;
        struct amdgpu_device *adev = attachment->adev;
        struct ttm_tt *ttm = bo->tbo.ttm;

        if (unlikely(!ttm->sg))
                return;

        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
        (void)ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);

        dma_unmap_sgtable(adev->dev, ttm->sg, direction, 0);
        sg_free_table(ttm->sg);
        kfree(ttm->sg);
        ttm->sg = NULL;
}

static void
kfd_mem_dmaunmap_dmabuf(struct kfd_mem_attachment *attachment)
{
        /* This is a no-op. We don't want to trigger eviction fences when
         * unmapping DMABufs. Therefore the invalidation (moving to system
         * domain) is done in kfd_mem_dmamap_dmabuf.
         */
}

/**
 * kfd_mem_dmaunmap_sg_bo() - Free DMA mapped sg_table of DOORBELL or MMIO BO
 * @mem: SG BO of the DOORBELL or MMIO resource on the owning device
 * @attachment: Virtual address attachment of the BO on accessing device
 *
 * The method performs following steps:
 *   - Signal TTM to mark memory pointed to by BO as GPU inaccessible
 *   - Free SG Table that is used to encapsulate DMA mapped memory of
 *          peer device's DOORBELL or MMIO memory
 *
 * This method is invoked in the following contexts:
 *     UNMapping of DOORBELL or MMIO BO on a device having access to its memory
 *     Eviction of DOOREBELL or MMIO BO on device having access to its memory
 *
 * Return: void
 */
static void
kfd_mem_dmaunmap_sg_bo(struct kgd_mem *mem,
                       struct kfd_mem_attachment *attachment)
{
        struct ttm_operation_ctx ctx = {.interruptible = true};
        struct amdgpu_bo *bo = attachment->bo_va->base.bo;
        struct amdgpu_device *adev = attachment->adev;
        struct ttm_tt *ttm = bo->tbo.ttm;
        enum dma_data_direction dir;

        if (unlikely(!ttm->sg)) {
                pr_debug("SG Table of BO is NULL");
                return;
        }

        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
        (void)ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);

        dir = mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
                                DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
        dma_unmap_resource(adev->dev, ttm->sg->sgl->dma_address,
                        ttm->sg->sgl->length, dir, DMA_ATTR_SKIP_CPU_SYNC);
        sg_free_table(ttm->sg);
        kfree(ttm->sg);
        ttm->sg = NULL;
        bo->tbo.sg = NULL;
}

static void
kfd_mem_dmaunmap_attachment(struct kgd_mem *mem,
                            struct kfd_mem_attachment *attachment)
{
        switch (attachment->type) {
        case KFD_MEM_ATT_SHARED:
                break;
        case KFD_MEM_ATT_USERPTR:
                kfd_mem_dmaunmap_userptr(mem, attachment);
                break;
        case KFD_MEM_ATT_DMABUF:
                kfd_mem_dmaunmap_dmabuf(attachment);
                break;
        case KFD_MEM_ATT_SG:
                kfd_mem_dmaunmap_sg_bo(mem, attachment);
                break;
        default:
                WARN_ON_ONCE(1);
        }
}

static int kfd_mem_export_dmabuf(struct kgd_mem *mem)
{
        if (!mem->dmabuf) {
                struct amdgpu_device *bo_adev;
                struct dma_buf *dmabuf;

                bo_adev = amdgpu_ttm_adev(mem->bo->tbo.bdev);
                dmabuf = drm_gem_prime_handle_to_dmabuf(&bo_adev->ddev, bo_adev->kfd.client.file,
                                               mem->gem_handle,
                        mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE ?
                                               DRM_RDWR : 0);
                if (IS_ERR(dmabuf))
                        return PTR_ERR(dmabuf);
                mem->dmabuf = dmabuf;
        }

        return 0;
}

static int
kfd_mem_attach_dmabuf(struct amdgpu_device *adev, struct kgd_mem *mem,
                      struct amdgpu_bo **bo)
{
        struct drm_gem_object *gobj;
        int ret;

        ret = kfd_mem_export_dmabuf(mem);
        if (ret)
                return ret;

        gobj = amdgpu_gem_prime_import(adev_to_drm(adev), mem->dmabuf);
        if (IS_ERR(gobj))
                return PTR_ERR(gobj);

        *bo = gem_to_amdgpu_bo(gobj);
        (*bo)->flags |= AMDGPU_GEM_CREATE_PREEMPTIBLE;

        return 0;
}

/* kfd_mem_attach - Add a BO to a VM
 *
 * Everything that needs to bo done only once when a BO is first added
 * to a VM. It can later be mapped and unmapped many times without
 * repeating these steps.
 *
 * 0. Create BO for DMA mapping, if needed
 * 1. Allocate and initialize BO VA entry data structure
 * 2. Add BO to the VM
 * 3. Determine ASIC-specific PTE flags
 * 4. Alloc page tables and directories if needed
 * 4a.  Validate new page tables and directories
 */
static int kfd_mem_attach(struct amdgpu_device *adev, struct kgd_mem *mem,
                struct amdgpu_vm *vm, bool is_aql)
{
        struct amdgpu_device *bo_adev = amdgpu_ttm_adev(mem->bo->tbo.bdev);
        unsigned long bo_size = mem->bo->tbo.base.size;
        uint64_t va = mem->va;
        struct kfd_mem_attachment *attachment[2] = {NULL, NULL};
        struct amdgpu_bo *bo[2] = {NULL, NULL};
        struct amdgpu_bo_va *bo_va;
        bool same_hive = false;
        struct drm_exec exec;
        int i, ret;

        if (!va) {
                pr_err("Invalid VA when adding BO to VM\n");
                return -EINVAL;
        }

        /* Determine access to VRAM, MMIO and DOORBELL BOs of peer devices
         *
         * The access path of MMIO and DOORBELL BOs of is always over PCIe.
         * In contrast the access path of VRAM BOs depens upon the type of
         * link that connects the peer device. Access over PCIe is allowed
         * if peer device has large BAR. In contrast, access over xGMI is
         * allowed for both small and large BAR configurations of peer device
         */
        if ((adev != bo_adev && !adev->apu_prefer_gtt) &&
            ((mem->domain == AMDGPU_GEM_DOMAIN_VRAM) ||
             (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL) ||
             (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP))) {
                if (mem->domain == AMDGPU_GEM_DOMAIN_VRAM)
                        same_hive = amdgpu_xgmi_same_hive(adev, bo_adev);
                if (!same_hive && !amdgpu_device_is_peer_accessible(bo_adev, adev))
                        return -EINVAL;
        }

        for (i = 0; i <= is_aql; i++) {
                attachment[i] = kzalloc(sizeof(*attachment[i]), GFP_KERNEL);
                if (unlikely(!attachment[i])) {
                        ret = -ENOMEM;
                        goto unwind;
                }

                pr_debug("\t add VA 0x%llx - 0x%llx to vm %p\n", va,
                         va + bo_size, vm);

                if ((adev == bo_adev && !(mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) ||
                    (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) && reuse_dmamap(adev, bo_adev)) ||
                    (mem->domain == AMDGPU_GEM_DOMAIN_GTT && reuse_dmamap(adev, bo_adev)) ||
                    same_hive) {
                        /* Mappings on the local GPU, or VRAM mappings in the
                         * local hive, or userptr, or GTT mapping can reuse dma map
                         * address space share the original BO
                         */
                        attachment[i]->type = KFD_MEM_ATT_SHARED;
                        bo[i] = mem->bo;
                        drm_gem_object_get(&bo[i]->tbo.base);
                } else if (i > 0) {
                        /* Multiple mappings on the same GPU share the BO */
                        attachment[i]->type = KFD_MEM_ATT_SHARED;
                        bo[i] = bo[0];
                        drm_gem_object_get(&bo[i]->tbo.base);
                } else if (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm)) {
                        /* Create an SG BO to DMA-map userptrs on other GPUs */
                        attachment[i]->type = KFD_MEM_ATT_USERPTR;
                        ret = create_dmamap_sg_bo(adev, mem, &bo[i]);
                        if (ret)
                                goto unwind;
                /* Handle DOORBELL BOs of peer devices and MMIO BOs of local and peer devices */
                } else if (mem->bo->tbo.type == ttm_bo_type_sg) {
                        WARN_ONCE(!(mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL ||
                                    mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP),
                                  "Handing invalid SG BO in ATTACH request");
                        attachment[i]->type = KFD_MEM_ATT_SG;
                        ret = create_dmamap_sg_bo(adev, mem, &bo[i]);
                        if (ret)
                                goto unwind;
                /* Enable acces to GTT and VRAM BOs of peer devices */
                } else if (mem->domain == AMDGPU_GEM_DOMAIN_GTT ||
                           mem->domain == AMDGPU_GEM_DOMAIN_VRAM) {
                        attachment[i]->type = KFD_MEM_ATT_DMABUF;
                        ret = kfd_mem_attach_dmabuf(adev, mem, &bo[i]);
                        if (ret)
                                goto unwind;
                        pr_debug("Employ DMABUF mechanism to enable peer GPU access\n");
                } else {
                        WARN_ONCE(true, "Handling invalid ATTACH request");
                        ret = -EINVAL;
                        goto unwind;
                }

                drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
                drm_exec_until_all_locked(&exec) {
                        ret = amdgpu_vm_lock_pd(vm, &exec, 0);
                        drm_exec_retry_on_contention(&exec);
                        if (unlikely(ret))
                                goto unwind;
                        ret = drm_exec_lock_obj(&exec, &bo[i]->tbo.base);
                        drm_exec_retry_on_contention(&exec);
                        if (unlikely(ret))
                                goto unwind;
                }

                bo_va = amdgpu_vm_bo_find(vm, bo[i]);
                if (!bo_va)
                        bo_va = amdgpu_vm_bo_add(adev, vm, bo[i]);
                else
                        ++bo_va->ref_count;
                attachment[i]->bo_va = bo_va;
                drm_exec_fini(&exec);
                if (unlikely(!attachment[i]->bo_va)) {
                        ret = -ENOMEM;
                        pr_err("Failed to add BO object to VM. ret == %d\n",
                               ret);
                        goto unwind;
                }
                attachment[i]->va = va;
                attachment[i]->pte_flags = get_pte_flags(adev, vm, mem);
                attachment[i]->adev = adev;
                list_add(&attachment[i]->list, &mem->attachments);

                va += bo_size;
        }

        return 0;

unwind:
        for (; i >= 0; i--) {
                if (!attachment[i])
                        continue;
                if (attachment[i]->bo_va) {
                        (void)amdgpu_bo_reserve(bo[i], true);
                        if (--attachment[i]->bo_va->ref_count == 0)
                                amdgpu_vm_bo_del(adev, attachment[i]->bo_va);
                        amdgpu_bo_unreserve(bo[i]);
                        list_del(&attachment[i]->list);
                }
                if (bo[i])
                        drm_gem_object_put(&bo[i]->tbo.base);
                kfree(attachment[i]);
        }
        return ret;
}

static void kfd_mem_detach(struct kfd_mem_attachment *attachment)
{
        struct amdgpu_bo *bo = attachment->bo_va->base.bo;

        pr_debug("\t remove VA 0x%llx in entry %p\n",
                        attachment->va, attachment);
        if (--attachment->bo_va->ref_count == 0)
                amdgpu_vm_bo_del(attachment->adev, attachment->bo_va);
        drm_gem_object_put(&bo->tbo.base);
        list_del(&attachment->list);
        kfree(attachment);
}

static void add_kgd_mem_to_kfd_bo_list(struct kgd_mem *mem,
                                struct amdkfd_process_info *process_info,
                                bool userptr)
{
        mutex_lock(&process_info->lock);
        if (userptr)
                list_add_tail(&mem->validate_list,
                              &process_info->userptr_valid_list);
        else
                list_add_tail(&mem->validate_list, &process_info->kfd_bo_list);
        mutex_unlock(&process_info->lock);
}

static void remove_kgd_mem_from_kfd_bo_list(struct kgd_mem *mem,
                struct amdkfd_process_info *process_info)
{
        mutex_lock(&process_info->lock);
        list_del(&mem->validate_list);
        mutex_unlock(&process_info->lock);
}

/* Initializes user pages. It registers the MMU notifier and validates
 * the userptr BO in the GTT domain.
 *
 * The BO must already be on the userptr_valid_list. Otherwise an
 * eviction and restore may happen that leaves the new BO unmapped
 * with the user mode queues running.
 *
 * Takes the process_info->lock to protect against concurrent restore
 * workers.
 *
 * Returns 0 for success, negative errno for errors.
 */
static int init_user_pages(struct kgd_mem *mem, uint64_t user_addr,
                           bool criu_resume)
{
        struct amdkfd_process_info *process_info = mem->process_info;
        struct amdgpu_bo *bo = mem->bo;
        struct ttm_operation_ctx ctx = { true, false };
        struct amdgpu_hmm_range *range;
        int ret = 0;

        mutex_lock(&process_info->lock);

        ret = amdgpu_ttm_tt_set_userptr(&bo->tbo, user_addr, 0);
        if (ret) {
                pr_err("%s: Failed to set userptr: %d\n", __func__, ret);
                goto out;
        }

        ret = amdgpu_hmm_register(bo, user_addr);
        if (ret) {
                pr_err("%s: Failed to register MMU notifier: %d\n",
                       __func__, ret);
                goto out;
        }

        if (criu_resume) {
                /*
                 * During a CRIU restore operation, the userptr buffer objects
                 * will be validated in the restore_userptr_work worker at a
                 * later stage when it is scheduled by another ioctl called by
                 * CRIU master process for the target pid for restore.
                 */
                mutex_lock(&process_info->notifier_lock);
                mem->invalid++;
                mutex_unlock(&process_info->notifier_lock);
                mutex_unlock(&process_info->lock);
                return 0;
        }

        range = amdgpu_hmm_range_alloc(NULL);
        if (unlikely(!range)) {
                ret = -ENOMEM;
                goto unregister_out;
        }

        ret = amdgpu_ttm_tt_get_user_pages(bo, range);
        if (ret) {
                amdgpu_hmm_range_free(range);
                if (ret == -EAGAIN)
                        pr_debug("Failed to get user pages, try again\n");
                else
                        pr_err("%s: Failed to get user pages: %d\n", __func__, ret);
                goto unregister_out;
        }

        ret = amdgpu_bo_reserve(bo, true);
        if (ret) {
                pr_err("%s: Failed to reserve BO\n", __func__);
                goto release_out;
        }

        amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm, range);

        amdgpu_bo_placement_from_domain(bo, mem->domain);
        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
        if (ret)
                pr_err("%s: failed to validate BO\n", __func__);
        amdgpu_bo_unreserve(bo);

release_out:
        amdgpu_hmm_range_free(range);
unregister_out:
        if (ret)
                amdgpu_hmm_unregister(bo);
out:
        mutex_unlock(&process_info->lock);
        return ret;
}

/* Reserving a BO and its page table BOs must happen atomically to
 * avoid deadlocks. Some operations update multiple VMs at once. Track
 * all the reservation info in a context structure. Optionally a sync
 * object can track VM updates.
 */
struct bo_vm_reservation_context {
        /* DRM execution context for the reservation */
        struct drm_exec exec;
        /* Number of VMs reserved */
        unsigned int n_vms;
        /* Pointer to sync object */
        struct amdgpu_sync *sync;
};

enum bo_vm_match {
        BO_VM_NOT_MAPPED = 0,   /* Match VMs where a BO is not mapped */
        BO_VM_MAPPED,           /* Match VMs where a BO is mapped     */
        BO_VM_ALL,              /* Match all VMs a BO was added to    */
};

/**
 * reserve_bo_and_vm - reserve a BO and a VM unconditionally.
 * @mem: KFD BO structure.
 * @vm: the VM to reserve.
 * @ctx: the struct that will be used in unreserve_bo_and_vms().
 */
static int reserve_bo_and_vm(struct kgd_mem *mem,
                              struct amdgpu_vm *vm,
                              struct bo_vm_reservation_context *ctx)
{
        struct amdgpu_bo *bo = mem->bo;
        int ret;

        WARN_ON(!vm);

        ctx->n_vms = 1;
        ctx->sync = &mem->sync;
        drm_exec_init(&ctx->exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
        drm_exec_until_all_locked(&ctx->exec) {
                ret = amdgpu_vm_lock_pd(vm, &ctx->exec, 2);
                drm_exec_retry_on_contention(&ctx->exec);
                if (unlikely(ret))
                        goto error;

                ret = drm_exec_prepare_obj(&ctx->exec, &bo->tbo.base, 1);
                drm_exec_retry_on_contention(&ctx->exec);
                if (unlikely(ret))
                        goto error;
        }
        return 0;

error:
        pr_err("Failed to reserve buffers in ttm.\n");
        drm_exec_fini(&ctx->exec);
        return ret;
}

/**
 * reserve_bo_and_cond_vms - reserve a BO and some VMs conditionally
 * @mem: KFD BO structure.
 * @vm: the VM to reserve. If NULL, then all VMs associated with the BO
 * is used. Otherwise, a single VM associated with the BO.
 * @map_type: the mapping status that will be used to filter the VMs.
 * @ctx: the struct that will be used in unreserve_bo_and_vms().
 *
 * Returns 0 for success, negative for failure.
 */
static int reserve_bo_and_cond_vms(struct kgd_mem *mem,
                                struct amdgpu_vm *vm, enum bo_vm_match map_type,
                                struct bo_vm_reservation_context *ctx)
{
        struct kfd_mem_attachment *entry;
        struct amdgpu_bo *bo = mem->bo;
        int ret;

        ctx->sync = &mem->sync;
        drm_exec_init(&ctx->exec, DRM_EXEC_INTERRUPTIBLE_WAIT |
                      DRM_EXEC_IGNORE_DUPLICATES, 0);
        drm_exec_until_all_locked(&ctx->exec) {
                ctx->n_vms = 0;
                list_for_each_entry(entry, &mem->attachments, list) {
                        if ((vm && vm != entry->bo_va->base.vm) ||
                                (entry->is_mapped != map_type
                                && map_type != BO_VM_ALL))
                                continue;

                        ret = amdgpu_vm_lock_pd(entry->bo_va->base.vm,
                                                &ctx->exec, 2);
                        drm_exec_retry_on_contention(&ctx->exec);
                        if (unlikely(ret))
                                goto error;
                        ++ctx->n_vms;
                }

                ret = drm_exec_prepare_obj(&ctx->exec, &bo->tbo.base, 1);
                drm_exec_retry_on_contention(&ctx->exec);
                if (unlikely(ret))
                        goto error;
        }
        return 0;

error:
        pr_err("Failed to reserve buffers in ttm.\n");
        drm_exec_fini(&ctx->exec);
        return ret;
}

/**
 * unreserve_bo_and_vms - Unreserve BO and VMs from a reservation context
 * @ctx: Reservation context to unreserve
 * @wait: Optionally wait for a sync object representing pending VM updates
 * @intr: Whether the wait is interruptible
 *
 * Also frees any resources allocated in
 * reserve_bo_and_(cond_)vm(s). Returns the status from
 * amdgpu_sync_wait.
 */
static int unreserve_bo_and_vms(struct bo_vm_reservation_context *ctx,
                                 bool wait, bool intr)
{
        int ret = 0;

        if (wait)
                ret = amdgpu_sync_wait(ctx->sync, intr);

        drm_exec_fini(&ctx->exec);
        ctx->sync = NULL;
        return ret;
}

static int unmap_bo_from_gpuvm(struct kgd_mem *mem,
                                struct kfd_mem_attachment *entry,
                                struct amdgpu_sync *sync)
{
        struct amdgpu_bo_va *bo_va = entry->bo_va;
        struct amdgpu_device *adev = entry->adev;
        struct amdgpu_vm *vm = bo_va->base.vm;

        if (bo_va->queue_refcount) {
                pr_debug("bo_va->queue_refcount %d\n", bo_va->queue_refcount);
                return -EBUSY;
        }

        (void)amdgpu_vm_bo_unmap(adev, bo_va, entry->va);

        /* VM entity stopped if process killed, don't clear freed pt bo */
        if (!amdgpu_vm_ready(vm))
                return 0;

        (void)amdgpu_vm_clear_freed(adev, vm, &bo_va->last_pt_update);

        (void)amdgpu_sync_fence(sync, bo_va->last_pt_update, GFP_KERNEL);

        return 0;
}

static int update_gpuvm_pte(struct kgd_mem *mem,
                            struct kfd_mem_attachment *entry,
                            struct amdgpu_sync *sync)
{
        struct amdgpu_bo_va *bo_va = entry->bo_va;
        struct amdgpu_device *adev = entry->adev;
        int ret;

        ret = kfd_mem_dmamap_attachment(mem, entry);
        if (ret)
                return ret;

        /* Update the page tables  */
        ret = amdgpu_vm_bo_update(adev, bo_va, false);
        if (ret) {
                pr_err("amdgpu_vm_bo_update failed\n");
                return ret;
        }

        return amdgpu_sync_fence(sync, bo_va->last_pt_update, GFP_KERNEL);
}

static int map_bo_to_gpuvm(struct kgd_mem *mem,
                           struct kfd_mem_attachment *entry,
                           struct amdgpu_sync *sync,
                           bool no_update_pte)
{
        int ret;

        /* Set virtual address for the allocation */
        ret = amdgpu_vm_bo_map(entry->adev, entry->bo_va, entry->va, 0,
                               amdgpu_bo_size(entry->bo_va->base.bo),
                               entry->pte_flags);
        if (ret) {
                pr_err("Failed to map VA 0x%llx in vm. ret %d\n",
                                entry->va, ret);
                return ret;
        }

        if (no_update_pte)
                return 0;

        ret = update_gpuvm_pte(mem, entry, sync);
        if (ret) {
                pr_err("update_gpuvm_pte() failed\n");
                goto update_gpuvm_pte_failed;
        }

        return 0;

update_gpuvm_pte_failed:
        unmap_bo_from_gpuvm(mem, entry, sync);
        kfd_mem_dmaunmap_attachment(mem, entry);
        return ret;
}

static int process_validate_vms(struct amdkfd_process_info *process_info,
                                struct ww_acquire_ctx *ticket)
{
        struct amdgpu_vm *peer_vm;
        int ret;

        list_for_each_entry(peer_vm, &process_info->vm_list_head,
                            vm_list_node) {
                ret = vm_validate_pt_pd_bos(peer_vm, ticket);
                if (ret)
                        return ret;
        }

        return 0;
}

static int process_sync_pds_resv(struct amdkfd_process_info *process_info,
                                 struct amdgpu_sync *sync)
{
        struct amdgpu_vm *peer_vm;
        int ret;

        list_for_each_entry(peer_vm, &process_info->vm_list_head,
                            vm_list_node) {
                struct amdgpu_bo *pd = peer_vm->root.bo;

                ret = amdgpu_sync_resv(NULL, sync, pd->tbo.base.resv,
                                       AMDGPU_SYNC_NE_OWNER,
                                       AMDGPU_FENCE_OWNER_KFD);
                if (ret)
                        return ret;
        }

        return 0;
}

static int process_update_pds(struct amdkfd_process_info *process_info,
                              struct amdgpu_sync *sync)
{
        struct amdgpu_vm *peer_vm;
        int ret;

        list_for_each_entry(peer_vm, &process_info->vm_list_head,
                            vm_list_node) {
                ret = vm_update_pds(peer_vm, sync);
                if (ret)
                        return ret;
        }

        return 0;
}

static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info,
                       struct dma_fence **ef)
{
        struct amdkfd_process_info *info = NULL;
        struct kfd_process *process = NULL;
        int ret;

        process = container_of(process_info, struct kfd_process, kgd_process_info);
        if (!*process_info) {
                info = kzalloc_obj(*info);
                if (!info)
                        return -ENOMEM;

                mutex_init(&info->lock);
                mutex_init(&info->notifier_lock);
                INIT_LIST_HEAD(&info->vm_list_head);
                INIT_LIST_HEAD(&info->kfd_bo_list);
                INIT_LIST_HEAD(&info->userptr_valid_list);
                INIT_LIST_HEAD(&info->userptr_inval_list);

                info->eviction_fence =
                        amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
                                                   current->mm,
                                                   NULL, process->context_id);
                if (!info->eviction_fence) {
                        pr_err("Failed to create eviction fence\n");
                        ret = -ENOMEM;
                        goto create_evict_fence_fail;
                }

                info->pid = get_task_pid(current, PIDTYPE_TGID);
                INIT_DELAYED_WORK(&info->restore_userptr_work,
                                  amdgpu_amdkfd_restore_userptr_worker);

                info->context_id = process->context_id;

                *process_info = info;
        }

        if (cmpxchg(&vm->process_info, NULL, *process_info) != NULL) {
                ret = -EINVAL;
                goto already_acquired;
        }

        /* Validate page directory and attach eviction fence */
        ret = amdgpu_bo_reserve(vm->root.bo, true);
        if (ret)
                goto reserve_pd_fail;
        ret = vm_validate_pt_pd_bos(vm, NULL);
        if (ret) {
                pr_err("validate_pt_pd_bos() failed\n");
                goto validate_pd_fail;
        }
        ret = amdgpu_bo_sync_wait(vm->root.bo,
                                  AMDGPU_FENCE_OWNER_KFD, false);
        if (ret)
                goto wait_pd_fail;
        ret = dma_resv_reserve_fences(vm->root.bo->tbo.base.resv, 1);
        if (ret)
                goto reserve_shared_fail;
        dma_resv_add_fence(vm->root.bo->tbo.base.resv,
                           &vm->process_info->eviction_fence->base,
                           DMA_RESV_USAGE_BOOKKEEP);
        amdgpu_bo_unreserve(vm->root.bo);

        /* Update process info */
        mutex_lock(&vm->process_info->lock);
        list_add_tail(&vm->vm_list_node,
                        &(vm->process_info->vm_list_head));
        vm->process_info->n_vms++;
        if (ef)
                *ef = dma_fence_get(&vm->process_info->eviction_fence->base);
        mutex_unlock(&vm->process_info->lock);

        return 0;

reserve_shared_fail:
wait_pd_fail:
validate_pd_fail:
        amdgpu_bo_unreserve(vm->root.bo);
reserve_pd_fail:
        vm->process_info = NULL;
already_acquired:
        if (info) {
                dma_fence_put(&info->eviction_fence->base);
                *process_info = NULL;
                put_pid(info->pid);
create_evict_fence_fail:
                mutex_destroy(&info->lock);
                mutex_destroy(&info->notifier_lock);
                kfree(info);
        }
        return ret;
}

/**
 * amdgpu_amdkfd_gpuvm_pin_bo() - Pins a BO using following criteria
 * @bo: Handle of buffer object being pinned
 * @domain: Domain into which BO should be pinned
 *
 *   - USERPTR BOs are UNPINNABLE and will return error
 *   - All other BO types (GTT, VRAM, MMIO and DOORBELL) will have their
 *     PIN count incremented. It is valid to PIN a BO multiple times
 *
 * Return: ZERO if successful in pinning, Non-Zero in case of error.
 */
static int amdgpu_amdkfd_gpuvm_pin_bo(struct amdgpu_bo *bo, u32 domain)
{
        int ret = 0;

        ret = amdgpu_bo_reserve(bo, false);
        if (unlikely(ret))
                return ret;

        if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS) {
                /*
                 * If bo is not contiguous on VRAM, move to system memory first to ensure
                 * we can get contiguous VRAM space after evicting other BOs.
                 */
                if (!(bo->tbo.resource->placement & TTM_PL_FLAG_CONTIGUOUS)) {
                        struct ttm_operation_ctx ctx = { true, false };

                        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
                        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
                        if (unlikely(ret)) {
                                pr_debug("validate bo 0x%p to GTT failed %d\n", &bo->tbo, ret);
                                goto out;
                        }
                }
        }

        ret = amdgpu_bo_pin(bo, domain);
        if (ret)
                pr_err("Error in Pinning BO to domain: %d\n", domain);

        amdgpu_bo_sync_wait(bo, AMDGPU_FENCE_OWNER_KFD, false);
out:
        amdgpu_bo_unreserve(bo);
        return ret;
}

/**
 * amdgpu_amdkfd_gpuvm_unpin_bo() - Unpins BO using following criteria
 * @bo: Handle of buffer object being unpinned
 *
 *   - Is a illegal request for USERPTR BOs and is ignored
 *   - All other BO types (GTT, VRAM, MMIO and DOORBELL) will have their
 *     PIN count decremented. Calls to UNPIN must balance calls to PIN
 */
static void amdgpu_amdkfd_gpuvm_unpin_bo(struct amdgpu_bo *bo)
{
        int ret = 0;

        ret = amdgpu_bo_reserve(bo, false);
        if (unlikely(ret))
                return;

        amdgpu_bo_unpin(bo);
        amdgpu_bo_unreserve(bo);
}

int amdgpu_amdkfd_gpuvm_acquire_process_vm(struct amdgpu_device *adev,
                                           struct amdgpu_vm *avm,
                                           void **process_info,
                                           struct dma_fence **ef)
{
        int ret;

        /* Already a compute VM? */
        if (avm->process_info)
                return -EINVAL;

        /* Convert VM into a compute VM */
        ret = amdgpu_vm_make_compute(adev, avm);
        if (ret)
                return ret;

        /* Initialize KFD part of the VM and process info */
        ret = init_kfd_vm(avm, process_info, ef);
        if (ret)
                return ret;

        amdgpu_vm_set_task_info(avm);

        return 0;
}

void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
                                    struct amdgpu_vm *vm)
{
        struct amdkfd_process_info *process_info = vm->process_info;

        if (!process_info)
                return;

        /* Update process info */
        mutex_lock(&process_info->lock);
        process_info->n_vms--;
        list_del(&vm->vm_list_node);
        mutex_unlock(&process_info->lock);

        vm->process_info = NULL;

        /* Release per-process resources when last compute VM is destroyed */
        if (!process_info->n_vms) {
                WARN_ON(!list_empty(&process_info->kfd_bo_list));
                WARN_ON(!list_empty(&process_info->userptr_valid_list));
                WARN_ON(!list_empty(&process_info->userptr_inval_list));

                dma_fence_put(&process_info->eviction_fence->base);
                cancel_delayed_work_sync(&process_info->restore_userptr_work);
                put_pid(process_info->pid);
                mutex_destroy(&process_info->lock);
                mutex_destroy(&process_info->notifier_lock);
                kfree(process_info);
        }
}

uint64_t amdgpu_amdkfd_gpuvm_get_process_page_dir(void *drm_priv)
{
        struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
        struct amdgpu_bo *pd = avm->root.bo;
        struct amdgpu_device *adev = amdgpu_ttm_adev(pd->tbo.bdev);

        if (adev->asic_type < CHIP_VEGA10)
                return avm->pd_phys_addr >> AMDGPU_GPU_PAGE_SHIFT;
        return avm->pd_phys_addr;
}

void amdgpu_amdkfd_block_mmu_notifications(void *p)
{
        struct amdkfd_process_info *pinfo = (struct amdkfd_process_info *)p;

        mutex_lock(&pinfo->lock);
        WRITE_ONCE(pinfo->block_mmu_notifications, true);
        mutex_unlock(&pinfo->lock);
}

int amdgpu_amdkfd_criu_resume(void *p)
{
        int ret = 0;
        struct amdkfd_process_info *pinfo = (struct amdkfd_process_info *)p;

        mutex_lock(&pinfo->lock);
        pr_debug("scheduling work\n");
        mutex_lock(&pinfo->notifier_lock);
        pinfo->evicted_bos++;
        mutex_unlock(&pinfo->notifier_lock);
        if (!READ_ONCE(pinfo->block_mmu_notifications)) {
                ret = -EINVAL;
                goto out_unlock;
        }
        WRITE_ONCE(pinfo->block_mmu_notifications, false);
        queue_delayed_work(system_freezable_wq,
                           &pinfo->restore_userptr_work, 0);

out_unlock:
        mutex_unlock(&pinfo->lock);
        return ret;
}

size_t amdgpu_amdkfd_get_available_memory(struct amdgpu_device *adev,
                                          uint8_t xcp_id)
{
        uint64_t reserved_for_pt =
                ESTIMATE_PT_SIZE(amdgpu_amdkfd_total_mem_size);
        struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
        uint64_t reserved_for_ras = (con ? con->reserved_pages_in_bytes : 0);
        ssize_t available;
        uint64_t vram_available, system_mem_available, ttm_mem_available;

        spin_lock(&kfd_mem_limit.mem_limit_lock);
        if (adev->apu_prefer_gtt && !adev->gmc.is_app_apu)
                vram_available = KFD_XCP_MEMORY_SIZE(adev, xcp_id)
                        - adev->kfd.vram_used_aligned[xcp_id];
        else
                vram_available = KFD_XCP_MEMORY_SIZE(adev, xcp_id)
                        - adev->kfd.vram_used_aligned[xcp_id]
                        - atomic64_read(&adev->vram_pin_size)
                        - reserved_for_pt
                        - reserved_for_ras;

        if (adev->apu_prefer_gtt) {
                system_mem_available = no_system_mem_limit ?
                                        kfd_mem_limit.max_system_mem_limit :
                                        kfd_mem_limit.max_system_mem_limit -
                                        kfd_mem_limit.system_mem_used;

                ttm_mem_available = kfd_mem_limit.max_ttm_mem_limit -
                                kfd_mem_limit.ttm_mem_used;

                available = min3(system_mem_available, ttm_mem_available,
                                 vram_available);
                available = ALIGN_DOWN(available, PAGE_SIZE);
        } else {
                available = ALIGN_DOWN(vram_available, VRAM_AVAILABLITY_ALIGN);
        }

        spin_unlock(&kfd_mem_limit.mem_limit_lock);

        if (available < 0)
                available = 0;

        return available;
}

int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
                struct amdgpu_device *adev, uint64_t va, uint64_t size,
                void *drm_priv, struct kgd_mem **mem,
                uint64_t *offset, uint32_t flags, bool criu_resume)
{
        struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
        struct amdgpu_fpriv *fpriv = container_of(avm, struct amdgpu_fpriv, vm);
        enum ttm_bo_type bo_type = ttm_bo_type_device;
        struct sg_table *sg = NULL;
        uint64_t user_addr = 0;
        struct amdgpu_bo *bo;
        struct drm_gem_object *gobj = NULL;
        u32 domain, alloc_domain;
        uint64_t aligned_size;
        int8_t xcp_id = -1;
        u64 alloc_flags;
        int ret;

        /*
         * Check on which domain to allocate BO
         */
        if (flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM) {
                domain = alloc_domain = AMDGPU_GEM_DOMAIN_VRAM;

                if (adev->apu_prefer_gtt) {
                        domain = AMDGPU_GEM_DOMAIN_GTT;
                        alloc_domain = AMDGPU_GEM_DOMAIN_GTT;
                        alloc_flags = 0;
                } else {
                        alloc_flags = AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE;
                        alloc_flags |= (flags & KFD_IOC_ALLOC_MEM_FLAGS_PUBLIC) ?
                        AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED : 0;

                        /* For contiguous VRAM allocation */
                        if (flags & KFD_IOC_ALLOC_MEM_FLAGS_CONTIGUOUS)
                                alloc_flags |= AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS;
                }
                xcp_id = fpriv->xcp_id == AMDGPU_XCP_NO_PARTITION ?
                                        0 : fpriv->xcp_id;
        } else if (flags & KFD_IOC_ALLOC_MEM_FLAGS_GTT) {
                domain = alloc_domain = AMDGPU_GEM_DOMAIN_GTT;
                alloc_flags = 0;
        } else {
                domain = AMDGPU_GEM_DOMAIN_GTT;
                alloc_domain = AMDGPU_GEM_DOMAIN_CPU;
                alloc_flags = AMDGPU_GEM_CREATE_PREEMPTIBLE;

                if (flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR) {
                        if (!offset || !*offset)
                                return -EINVAL;
                        user_addr = untagged_addr(*offset);
                } else if (flags & (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
                                    KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) {
                        bo_type = ttm_bo_type_sg;
                        if (size > UINT_MAX)
                                return -EINVAL;
                        sg = create_sg_table(*offset, size);
                        if (!sg)
                                return -ENOMEM;
                } else {
                        return -EINVAL;
                }
        }

        if (flags & KFD_IOC_ALLOC_MEM_FLAGS_COHERENT)
                alloc_flags |= AMDGPU_GEM_CREATE_COHERENT;
        if (flags & KFD_IOC_ALLOC_MEM_FLAGS_EXT_COHERENT)
                alloc_flags |= AMDGPU_GEM_CREATE_EXT_COHERENT;
        if (flags & KFD_IOC_ALLOC_MEM_FLAGS_UNCACHED)
                alloc_flags |= AMDGPU_GEM_CREATE_UNCACHED;

        *mem = kzalloc_obj(struct kgd_mem);
        if (!*mem) {
                ret = -ENOMEM;
                goto err;
        }
        INIT_LIST_HEAD(&(*mem)->attachments);
        mutex_init(&(*mem)->lock);
        (*mem)->aql_queue = !!(flags & KFD_IOC_ALLOC_MEM_FLAGS_AQL_QUEUE_MEM);

        /* Workaround for AQL queue wraparound bug. Map the same
         * memory twice. That means we only actually allocate half
         * the memory.
         */
        if ((*mem)->aql_queue)
                size >>= 1;
        aligned_size = PAGE_ALIGN(size);

        (*mem)->alloc_flags = flags;

        amdgpu_sync_create(&(*mem)->sync);

        ret = amdgpu_amdkfd_reserve_mem_limit(adev, aligned_size, flags,
                                              xcp_id);
        if (ret) {
                pr_debug("Insufficient memory\n");
                goto err_reserve_limit;
        }

        pr_debug("\tcreate BO VA 0x%llx size 0x%llx domain %s xcp_id %d\n",
                 va, (*mem)->aql_queue ? size << 1 : size,
                 domain_string(alloc_domain), xcp_id);

        ret = amdgpu_gem_object_create(adev, aligned_size, 1, alloc_domain, alloc_flags,
                                       bo_type, NULL, &gobj, xcp_id + 1);
        if (ret) {
                pr_debug("Failed to create BO on domain %s. ret %d\n",
                         domain_string(alloc_domain), ret);
                goto err_bo_create;
        }
        ret = drm_vma_node_allow(&gobj->vma_node, drm_priv);
        if (ret) {
                pr_debug("Failed to allow vma node access. ret %d\n", ret);
                goto err_node_allow;
        }
        ret = drm_gem_handle_create(adev->kfd.client.file, gobj, &(*mem)->gem_handle);
        if (ret)
                goto err_gem_handle_create;
        bo = gem_to_amdgpu_bo(gobj);
        if (bo_type == ttm_bo_type_sg) {
                bo->tbo.sg = sg;
                bo->tbo.ttm->sg = sg;
        }
        bo->kfd_bo = *mem;
        (*mem)->bo = bo;
        if (user_addr)
                bo->flags |= AMDGPU_AMDKFD_CREATE_USERPTR_BO;

        (*mem)->va = va;
        (*mem)->domain = domain;
        (*mem)->mapped_to_gpu_memory = 0;
        (*mem)->process_info = avm->process_info;

        add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, user_addr);

        if (user_addr) {
                pr_debug("creating userptr BO for user_addr = %llx\n", user_addr);
                ret = init_user_pages(*mem, user_addr, criu_resume);
                if (ret)
                        goto allocate_init_user_pages_failed;
        } else  if (flags & (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
                                KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) {
                ret = amdgpu_amdkfd_gpuvm_pin_bo(bo, AMDGPU_GEM_DOMAIN_GTT);
                if (ret) {
                        pr_err("Pinning MMIO/DOORBELL BO during ALLOC FAILED\n");
                        goto err_pin_bo;
                }
                bo->allowed_domains = AMDGPU_GEM_DOMAIN_GTT;
                bo->preferred_domains = AMDGPU_GEM_DOMAIN_GTT;
        } else {
                mutex_lock(&avm->process_info->lock);
                if (avm->process_info->eviction_fence &&
                    !dma_fence_is_signaled(&avm->process_info->eviction_fence->base))
                        ret = amdgpu_amdkfd_bo_validate_and_fence(bo, domain,
                                &avm->process_info->eviction_fence->base);
                mutex_unlock(&avm->process_info->lock);
                if (ret)
                        goto err_validate_bo;
        }

        if (offset)
                *offset = amdgpu_bo_mmap_offset(bo);

        return 0;

allocate_init_user_pages_failed:
err_pin_bo:
err_validate_bo:
        remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
        drm_gem_handle_delete(adev->kfd.client.file, (*mem)->gem_handle);
err_gem_handle_create:
        drm_vma_node_revoke(&gobj->vma_node, drm_priv);
err_node_allow:
        /* Don't unreserve system mem limit twice */
        goto err_reserve_limit;
err_bo_create:
        amdgpu_amdkfd_unreserve_mem_limit(adev, aligned_size, flags, xcp_id);
err_reserve_limit:
        amdgpu_sync_free(&(*mem)->sync);
        mutex_destroy(&(*mem)->lock);
        if (gobj)
                drm_gem_object_put(gobj);
        else
                kfree(*mem);
err:
        if (sg) {
                sg_free_table(sg);
                kfree(sg);
        }
        return ret;
}

int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
                struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv,
                uint64_t *size)
{
        struct amdkfd_process_info *process_info = mem->process_info;
        unsigned long bo_size = mem->bo->tbo.base.size;
        bool use_release_notifier = (mem->bo->kfd_bo == mem);
        struct kfd_mem_attachment *entry, *tmp;
        struct bo_vm_reservation_context ctx;
        unsigned int mapped_to_gpu_memory;
        int ret;
        bool is_imported = false;

        mutex_lock(&mem->lock);

        /* Unpin MMIO/DOORBELL BO's that were pinned during allocation */
        if (mem->alloc_flags &
            (KFD_IOC_ALLOC_MEM_FLAGS_DOORBELL |
             KFD_IOC_ALLOC_MEM_FLAGS_MMIO_REMAP)) {
                amdgpu_amdkfd_gpuvm_unpin_bo(mem->bo);
        }

        mapped_to_gpu_memory = mem->mapped_to_gpu_memory;
        is_imported = mem->is_imported;
        mutex_unlock(&mem->lock);
        /* lock is not needed after this, since mem is unused and will
         * be freed anyway
         */

        if (mapped_to_gpu_memory > 0) {
                pr_debug("BO VA 0x%llx size 0x%lx is still mapped.\n",
                                mem->va, bo_size);
                return -EBUSY;
        }

        /* Make sure restore workers don't access the BO any more */
        mutex_lock(&process_info->lock);
        if (!list_empty(&mem->validate_list))
                list_del_init(&mem->validate_list);
        mutex_unlock(&process_info->lock);

        ret = reserve_bo_and_cond_vms(mem, NULL, BO_VM_ALL, &ctx);
        if (unlikely(ret))
                return ret;

        /* Cleanup user pages and MMU notifiers */
        if (amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm)) {
                amdgpu_hmm_unregister(mem->bo);
                amdgpu_hmm_range_free(mem->range);
                mem->range = NULL;
        }

        amdgpu_amdkfd_remove_eviction_fence(mem->bo,
                                        process_info->eviction_fence);
        pr_debug("Release VA 0x%llx - 0x%llx\n", mem->va,
                mem->va + bo_size * (1 + mem->aql_queue));

        /* Remove from VM internal data structures */
        list_for_each_entry_safe(entry, tmp, &mem->attachments, list) {
                kfd_mem_dmaunmap_attachment(mem, entry);
                kfd_mem_detach(entry);
        }

        ret = unreserve_bo_and_vms(&ctx, false, false);

        /* Free the sync object */
        amdgpu_sync_free(&mem->sync);

        /* If the SG is not NULL, it's one we created for a doorbell or mmio
         * remap BO. We need to free it.
         */
        if (mem->bo->tbo.sg) {
                sg_free_table(mem->bo->tbo.sg);
                kfree(mem->bo->tbo.sg);
        }

        /* Update the size of the BO being freed if it was allocated from
         * VRAM and is not imported. For APP APU VRAM allocations are done
         * in GTT domain
         */
        if (size) {
                if (!is_imported &&
                   mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_VRAM)
                        *size = bo_size;
                else
                        *size = 0;
        }

        /* Free the BO*/
        drm_vma_node_revoke(&mem->bo->tbo.base.vma_node, drm_priv);
        drm_gem_handle_delete(adev->kfd.client.file, mem->gem_handle);
        if (mem->dmabuf) {
                dma_buf_put(mem->dmabuf);
                mem->dmabuf = NULL;
        }
        mutex_destroy(&mem->lock);

        /* If this releases the last reference, it will end up calling
         * amdgpu_amdkfd_release_notify and kfree the mem struct. That's why
         * this needs to be the last call here.
         */
        drm_gem_object_put(&mem->bo->tbo.base);

        /*
         * For kgd_mem allocated in import_obj_create() via
         * amdgpu_amdkfd_gpuvm_import_dmabuf_fd(),
         * explicitly free it here.
         */
        if (!use_release_notifier)
                kfree(mem);

        return ret;
}

int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(
                struct amdgpu_device *adev, struct kgd_mem *mem,
                void *drm_priv)
{
        struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
        int ret;
        struct amdgpu_bo *bo;
        uint32_t domain;
        struct kfd_mem_attachment *entry;
        struct bo_vm_reservation_context ctx;
        unsigned long bo_size;
        bool is_invalid_userptr = false;

        bo = mem->bo;
        if (!bo) {
                pr_err("Invalid BO when mapping memory to GPU\n");
                return -EINVAL;
        }

        /* Make sure restore is not running concurrently. Since we
         * don't map invalid userptr BOs, we rely on the next restore
         * worker to do the mapping
         */
        mutex_lock(&mem->process_info->lock);

        /* Lock notifier lock. If we find an invalid userptr BO, we can be
         * sure that the MMU notifier is no longer running
         * concurrently and the queues are actually stopped
         */
        if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) {
                mutex_lock(&mem->process_info->notifier_lock);
                is_invalid_userptr = !!mem->invalid;
                mutex_unlock(&mem->process_info->notifier_lock);
        }

        mutex_lock(&mem->lock);

        domain = mem->domain;
        bo_size = bo->tbo.base.size;

        pr_debug("Map VA 0x%llx - 0x%llx to vm %p domain %s\n",
                        mem->va,
                        mem->va + bo_size * (1 + mem->aql_queue),
                        avm, domain_string(domain));

        if (!kfd_mem_is_attached(avm, mem)) {
                ret = kfd_mem_attach(adev, mem, avm, mem->aql_queue);
                if (ret)
                        goto out;
        }

        ret = reserve_bo_and_vm(mem, avm, &ctx);
        if (unlikely(ret))
                goto out;

        /* Userptr can be marked as "not invalid", but not actually be
         * validated yet (still in the system domain). In that case
         * the queues are still stopped and we can leave mapping for
         * the next restore worker
         */
        if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) &&
            bo->tbo.resource->mem_type == TTM_PL_SYSTEM)
                is_invalid_userptr = true;

        ret = vm_validate_pt_pd_bos(avm, NULL);
        if (unlikely(ret))
                goto out_unreserve;

        list_for_each_entry(entry, &mem->attachments, list) {
                if (entry->bo_va->base.vm != avm || entry->is_mapped)
                        continue;

                pr_debug("\t map VA 0x%llx - 0x%llx in entry %p\n",
                         entry->va, entry->va + bo_size, entry);

                ret = map_bo_to_gpuvm(mem, entry, ctx.sync,
                                      is_invalid_userptr);
                if (ret) {
                        pr_err("Failed to map bo to gpuvm\n");
                        goto out_unreserve;
                }

                ret = vm_update_pds(avm, ctx.sync);
                if (ret) {
                        pr_err("Failed to update page directories\n");
                        goto out_unreserve;
                }

                entry->is_mapped = true;
                mem->mapped_to_gpu_memory++;
                pr_debug("\t INC mapping count %d\n",
                         mem->mapped_to_gpu_memory);
        }

        ret = unreserve_bo_and_vms(&ctx, false, false);

        goto out;

out_unreserve:
        unreserve_bo_and_vms(&ctx, false, false);
out:
        mutex_unlock(&mem->process_info->lock);
        mutex_unlock(&mem->lock);
        return ret;
}

int amdgpu_amdkfd_gpuvm_dmaunmap_mem(struct kgd_mem *mem, void *drm_priv)
{
        struct kfd_mem_attachment *entry;
        struct amdgpu_vm *vm;
        int ret;

        vm = drm_priv_to_vm(drm_priv);

        mutex_lock(&mem->lock);

        ret = amdgpu_bo_reserve(mem->bo, true);
        if (ret)
                goto out;

        list_for_each_entry(entry, &mem->attachments, list) {
                if (entry->bo_va->base.vm != vm)
                        continue;
                if (entry->bo_va->base.bo->tbo.ttm &&
                    !entry->bo_va->base.bo->tbo.ttm->sg)
                        continue;

                kfd_mem_dmaunmap_attachment(mem, entry);
        }

        amdgpu_bo_unreserve(mem->bo);
out:
        mutex_unlock(&mem->lock);

        return ret;
}

int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
                struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv)
{
        struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
        unsigned long bo_size = mem->bo->tbo.base.size;
        struct kfd_mem_attachment *entry;
        struct bo_vm_reservation_context ctx;
        int ret;

        mutex_lock(&mem->lock);

        ret = reserve_bo_and_cond_vms(mem, avm, BO_VM_MAPPED, &ctx);
        if (unlikely(ret))
                goto out;
        /* If no VMs were reserved, it means the BO wasn't actually mapped */
        if (ctx.n_vms == 0) {
                ret = -EINVAL;
                goto unreserve_out;
        }

        ret = vm_validate_pt_pd_bos(avm, NULL);
        if (unlikely(ret))
                goto unreserve_out;

        pr_debug("Unmap VA 0x%llx - 0x%llx from vm %p\n",
                mem->va,
                mem->va + bo_size * (1 + mem->aql_queue),
                avm);

        list_for_each_entry(entry, &mem->attachments, list) {
                if (entry->bo_va->base.vm != avm || !entry->is_mapped)
                        continue;

                pr_debug("\t unmap VA 0x%llx - 0x%llx from entry %p\n",
                         entry->va, entry->va + bo_size, entry);

                ret = unmap_bo_from_gpuvm(mem, entry, ctx.sync);
                if (ret)
                        goto unreserve_out;

                entry->is_mapped = false;

                mem->mapped_to_gpu_memory--;
                pr_debug("\t DEC mapping count %d\n",
                         mem->mapped_to_gpu_memory);
        }

unreserve_out:
        unreserve_bo_and_vms(&ctx, false, false);
out:
        mutex_unlock(&mem->lock);
        return ret;
}

int amdgpu_amdkfd_gpuvm_sync_memory(
                struct amdgpu_device *adev, struct kgd_mem *mem, bool intr)
{
        struct amdgpu_sync sync;
        int ret;

        amdgpu_sync_create(&sync);

        mutex_lock(&mem->lock);
        amdgpu_sync_clone(&mem->sync, &sync);
        mutex_unlock(&mem->lock);

        ret = amdgpu_sync_wait(&sync, intr);
        amdgpu_sync_free(&sync);
        return ret;
}

/**
 * amdgpu_amdkfd_map_gtt_bo_to_gart - Map BO to GART and increment reference count
 * @bo: Buffer object to be mapped
 * @bo_gart: Return bo reference
 *
 * Before return, bo reference count is incremented. To release the reference and unpin/
 * unmap the BO, call amdgpu_amdkfd_free_kernel_mem.
 */
int amdgpu_amdkfd_map_gtt_bo_to_gart(struct amdgpu_bo *bo, struct amdgpu_bo **bo_gart)
{
        int ret;

        ret = amdgpu_bo_reserve(bo, true);
        if (ret) {
                pr_err("Failed to reserve bo. ret %d\n", ret);
                goto err_reserve_bo_failed;
        }

        ret = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT);
        if (ret) {
                pr_err("Failed to pin bo. ret %d\n", ret);
                goto err_pin_bo_failed;
        }

        ret = amdgpu_ttm_alloc_gart(&bo->tbo);
        if (ret) {
                pr_err("Failed to bind bo to GART. ret %d\n", ret);
                goto err_map_bo_gart_failed;
        }

        amdgpu_amdkfd_remove_eviction_fence(
                bo, bo->vm_bo->vm->process_info->eviction_fence);

        amdgpu_bo_unreserve(bo);

        *bo_gart = amdgpu_bo_ref(bo);

        return 0;

err_map_bo_gart_failed:
        amdgpu_bo_unpin(bo);
err_pin_bo_failed:
        amdgpu_bo_unreserve(bo);
err_reserve_bo_failed:

        return ret;
}

/** amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel() - Map a GTT BO for kernel CPU access
 *
 * @mem: Buffer object to be mapped for CPU access
 * @kptr[out]: pointer in kernel CPU address space
 * @size[out]: size of the buffer
 *
 * Pins the BO and maps it for kernel CPU access. The eviction fence is removed
 * from the BO, since pinned BOs cannot be evicted. The bo must remain on the
 * validate_list, so the GPU mapping can be restored after a page table was
 * evicted.
 *
 * Return: 0 on success, error code on failure
 */
int amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel(struct kgd_mem *mem,
                                             void **kptr, uint64_t *size)
{
        int ret;
        struct amdgpu_bo *bo = mem->bo;

        if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) {
                pr_err("userptr can't be mapped to kernel\n");
                return -EINVAL;
        }

        mutex_lock(&mem->process_info->lock);

        ret = amdgpu_bo_reserve(bo, true);
        if (ret) {
                pr_err("Failed to reserve bo. ret %d\n", ret);
                goto bo_reserve_failed;
        }

        ret = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT);
        if (ret) {
                pr_err("Failed to pin bo. ret %d\n", ret);
                goto pin_failed;
        }

        ret = amdgpu_bo_kmap(bo, kptr);
        if (ret) {
                pr_err("Failed to map bo to kernel. ret %d\n", ret);
                goto kmap_failed;
        }

        amdgpu_amdkfd_remove_eviction_fence(
                bo, mem->process_info->eviction_fence);

        if (size)
                *size = amdgpu_bo_size(bo);

        amdgpu_bo_unreserve(bo);

        mutex_unlock(&mem->process_info->lock);
        return 0;

kmap_failed:
        amdgpu_bo_unpin(bo);
pin_failed:
        amdgpu_bo_unreserve(bo);
bo_reserve_failed:
        mutex_unlock(&mem->process_info->lock);

        return ret;
}

/** amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel() - Unmap a GTT BO for kernel CPU access
 *
 * @mem: Buffer object to be unmapped for CPU access
 *
 * Removes the kernel CPU mapping and unpins the BO. It does not restore the
 * eviction fence, so this function should only be used for cleanup before the
 * BO is destroyed.
 */
void amdgpu_amdkfd_gpuvm_unmap_gtt_bo_from_kernel(struct kgd_mem *mem)
{
        struct amdgpu_bo *bo = mem->bo;

        (void)amdgpu_bo_reserve(bo, true);
        amdgpu_bo_kunmap(bo);
        amdgpu_bo_unpin(bo);
        amdgpu_bo_unreserve(bo);
}

int amdgpu_amdkfd_gpuvm_get_vm_fault_info(struct amdgpu_device *adev,
                                          struct kfd_vm_fault_info *mem)
{
        if (atomic_read_acquire(&adev->gmc.vm_fault_info_updated) == 1) {
                *mem = *adev->gmc.vm_fault_info;
                atomic_set_release(&adev->gmc.vm_fault_info_updated, 0);
        }
        return 0;
}

static int import_obj_create(struct amdgpu_device *adev,
                             struct dma_buf *dma_buf,
                             struct drm_gem_object *obj,
                             uint64_t va, void *drm_priv,
                             struct kgd_mem **mem, uint64_t *size,
                             uint64_t *mmap_offset)
{
        struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
        struct amdgpu_bo *bo;
        int ret;

        bo = gem_to_amdgpu_bo(obj);
        if (!(bo->preferred_domains & (AMDGPU_GEM_DOMAIN_VRAM |
                                    AMDGPU_GEM_DOMAIN_GTT)))
                /* Only VRAM and GTT BOs are supported */
                return -EINVAL;

        *mem = kzalloc_obj(struct kgd_mem);
        if (!*mem)
                return -ENOMEM;

        ret = drm_vma_node_allow(&obj->vma_node, drm_priv);
        if (ret)
                goto err_free_mem;

        if (size)
                *size = amdgpu_bo_size(bo);

        if (mmap_offset)
                *mmap_offset = amdgpu_bo_mmap_offset(bo);

        INIT_LIST_HEAD(&(*mem)->attachments);
        mutex_init(&(*mem)->lock);

        (*mem)->alloc_flags =
                ((bo->preferred_domains & AMDGPU_GEM_DOMAIN_VRAM) ?
                KFD_IOC_ALLOC_MEM_FLAGS_VRAM : KFD_IOC_ALLOC_MEM_FLAGS_GTT)
                | KFD_IOC_ALLOC_MEM_FLAGS_WRITABLE
                | KFD_IOC_ALLOC_MEM_FLAGS_EXECUTABLE;

        get_dma_buf(dma_buf);
        (*mem)->dmabuf = dma_buf;
        (*mem)->bo = bo;
        (*mem)->va = va;
        (*mem)->domain = (bo->preferred_domains & AMDGPU_GEM_DOMAIN_VRAM) &&
                         !adev->apu_prefer_gtt ?
                         AMDGPU_GEM_DOMAIN_VRAM : AMDGPU_GEM_DOMAIN_GTT;

        (*mem)->mapped_to_gpu_memory = 0;
        (*mem)->process_info = avm->process_info;
        add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, false);
        amdgpu_sync_create(&(*mem)->sync);
        (*mem)->is_imported = true;

        mutex_lock(&avm->process_info->lock);
        if (avm->process_info->eviction_fence &&
            !dma_fence_is_signaled(&avm->process_info->eviction_fence->base))
                ret = amdgpu_amdkfd_bo_validate_and_fence(bo, (*mem)->domain,
                                &avm->process_info->eviction_fence->base);
        mutex_unlock(&avm->process_info->lock);
        if (ret)
                goto err_remove_mem;

        return 0;

err_remove_mem:
        remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
        drm_vma_node_revoke(&obj->vma_node, drm_priv);
err_free_mem:
        kfree(*mem);
        return ret;
}

int amdgpu_amdkfd_gpuvm_import_dmabuf_fd(struct amdgpu_device *adev, int fd,
                                         uint64_t va, void *drm_priv,
                                         struct kgd_mem **mem, uint64_t *size,
                                         uint64_t *mmap_offset)
{
        struct drm_gem_object *obj;
        uint32_t handle;
        int ret;

        ret = drm_gem_prime_fd_to_handle(&adev->ddev, adev->kfd.client.file, fd,
                                         &handle);
        if (ret)
                return ret;
        obj = drm_gem_object_lookup(adev->kfd.client.file, handle);
        if (!obj) {
                ret = -EINVAL;
                goto err_release_handle;
        }

        ret = import_obj_create(adev, obj->dma_buf, obj, va, drm_priv, mem, size,
                                mmap_offset);
        if (ret)
                goto err_put_obj;

        (*mem)->gem_handle = handle;

        return 0;

err_put_obj:
        drm_gem_object_put(obj);
err_release_handle:
        drm_gem_handle_delete(adev->kfd.client.file, handle);
        return ret;
}

int amdgpu_amdkfd_gpuvm_export_dmabuf(struct kgd_mem *mem,
                                      struct dma_buf **dma_buf)
{
        int ret;

        mutex_lock(&mem->lock);
        ret = kfd_mem_export_dmabuf(mem);
        if (ret)
                goto out;

        get_dma_buf(mem->dmabuf);
        *dma_buf = mem->dmabuf;
out:
        mutex_unlock(&mem->lock);
        return ret;
}

/* Evict a userptr BO by stopping the queues if necessary
 *
 * Runs in MMU notifier, may be in RECLAIM_FS context. This means it
 * cannot do any memory allocations, and cannot take any locks that
 * are held elsewhere while allocating memory.
 *
 * It doesn't do anything to the BO itself. The real work happens in
 * restore, where we get updated page addresses. This function only
 * ensures that GPU access to the BO is stopped.
 */
int amdgpu_amdkfd_evict_userptr(struct mmu_interval_notifier *mni,
                                unsigned long cur_seq, struct kgd_mem *mem)
{
        struct amdkfd_process_info *process_info = mem->process_info;
        int r = 0;

        /* Do not process MMU notifications during CRIU restore until
         * KFD_CRIU_OP_RESUME IOCTL is received
         */
        if (READ_ONCE(process_info->block_mmu_notifications))
                return 0;

        mutex_lock(&process_info->notifier_lock);
        mmu_interval_set_seq(mni, cur_seq);

        mem->invalid++;
        if (++process_info->evicted_bos == 1) {
                /* First eviction, stop the queues */
                r = kgd2kfd_quiesce_mm(mni->mm,
                                       KFD_QUEUE_EVICTION_TRIGGER_USERPTR);

                if (r && r != -ESRCH)
                        pr_err("Failed to quiesce KFD\n");

                if (r != -ESRCH)
                        queue_delayed_work(system_freezable_wq,
                                &process_info->restore_userptr_work,
                                msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS));
        }
        mutex_unlock(&process_info->notifier_lock);

        return r;
}

/* Update invalid userptr BOs
 *
 * Moves invalidated (evicted) userptr BOs from userptr_valid_list to
 * userptr_inval_list and updates user pages for all BOs that have
 * been invalidated since their last update.
 */
static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
                                     struct mm_struct *mm)
{
        struct kgd_mem *mem, *tmp_mem;
        struct amdgpu_bo *bo;
        struct ttm_operation_ctx ctx = { false, false };
        uint32_t invalid;
        int ret = 0;

        mutex_lock(&process_info->notifier_lock);

        /* Move all invalidated BOs to the userptr_inval_list */
        list_for_each_entry_safe(mem, tmp_mem,
                                 &process_info->userptr_valid_list,
                                 validate_list)
                if (mem->invalid)
                        list_move_tail(&mem->validate_list,
                                       &process_info->userptr_inval_list);

        /* Go through userptr_inval_list and update any invalid user_pages */
        list_for_each_entry(mem, &process_info->userptr_inval_list,
                            validate_list) {
                invalid = mem->invalid;
                if (!invalid)
                        /* BO hasn't been invalidated since the last
                         * revalidation attempt. Keep its page list.
                         */
                        continue;

                bo = mem->bo;

                amdgpu_hmm_range_free(mem->range);
                mem->range = NULL;

                /* BO reservations and getting user pages (hmm_range_fault)
                 * must happen outside the notifier lock
                 */
                mutex_unlock(&process_info->notifier_lock);

                /* Move the BO to system (CPU) domain if necessary to unmap
                 * and free the SG table
                 */
                if (bo->tbo.resource->mem_type != TTM_PL_SYSTEM) {
                        if (amdgpu_bo_reserve(bo, true))
                                return -EAGAIN;
                        amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU);
                        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
                        amdgpu_bo_unreserve(bo);
                        if (ret) {
                                pr_err("%s: Failed to invalidate userptr BO\n",
                                       __func__);
                                return -EAGAIN;
                        }
                }

                mem->range = amdgpu_hmm_range_alloc(NULL);
                if (unlikely(!mem->range))
                        return -ENOMEM;
                /* Get updated user pages */
                ret = amdgpu_ttm_tt_get_user_pages(bo, mem->range);
                if (ret) {
                        amdgpu_hmm_range_free(mem->range);
                        mem->range = NULL;
                        pr_debug("Failed %d to get user pages\n", ret);

                        /* Return -EFAULT bad address error as success. It will
                         * fail later with a VM fault if the GPU tries to access
                         * it. Better than hanging indefinitely with stalled
                         * user mode queues.
                         *
                         * Return other error -EBUSY or -ENOMEM to retry restore
                         */
                        if (ret != -EFAULT)
                                return ret;

                        /* If applications unmap memory before destroying the userptr
                         * from the KFD, trigger a segmentation fault in VM debug mode.
                         */
                        if (amdgpu_ttm_adev(bo->tbo.bdev)->debug_vm_userptr) {
                                struct kfd_process *p;

                                pr_err("Pid %d unmapped memory before destroying userptr at GPU addr 0x%llx\n",
                                                                pid_nr(process_info->pid), mem->va);

                                // Send GPU VM fault to user space
                                p = kfd_lookup_process_by_pid(process_info->pid);
                                if (p) {
                                        kfd_signal_vm_fault_event_with_userptr(p, mem->va);
                                        kfd_unref_process(p);
                                }
                        }

                        ret = 0;
                }

                amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm, mem->range);

                mutex_lock(&process_info->notifier_lock);

                /* Mark the BO as valid unless it was invalidated
                 * again concurrently.
                 */
                if (mem->invalid != invalid) {
                        ret = -EAGAIN;
                        goto unlock_out;
                }
                 /* set mem valid if mem has hmm range associated */
                if (mem->range)
                        mem->invalid = 0;
        }

unlock_out:
        mutex_unlock(&process_info->notifier_lock);

        return ret;
}

/* Validate invalid userptr BOs
 *
 * Validates BOs on the userptr_inval_list. Also updates GPUVM page tables
 * with new page addresses and waits for the page table updates to complete.
 */
static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
{
        struct ttm_operation_ctx ctx = { false, false };
        struct amdgpu_sync sync;
        struct drm_exec exec;

        struct amdgpu_vm *peer_vm;
        struct kgd_mem *mem, *tmp_mem;
        struct amdgpu_bo *bo;
        int ret;

        amdgpu_sync_create(&sync);

        drm_exec_init(&exec, 0, 0);
        /* Reserve all BOs and page tables for validation */
        drm_exec_until_all_locked(&exec) {
                /* Reserve all the page directories */
                list_for_each_entry(peer_vm, &process_info->vm_list_head,
                                    vm_list_node) {
                        ret = amdgpu_vm_lock_pd(peer_vm, &exec, 2);
                        drm_exec_retry_on_contention(&exec);
                        if (unlikely(ret))
                                goto unreserve_out;
                }

                /* Reserve the userptr_inval_list entries to resv_list */
                list_for_each_entry(mem, &process_info->userptr_inval_list,
                                    validate_list) {
                        struct drm_gem_object *gobj;

                        gobj = &mem->bo->tbo.base;
                        ret = drm_exec_prepare_obj(&exec, gobj, 1);
                        drm_exec_retry_on_contention(&exec);
                        if (unlikely(ret))
                                goto unreserve_out;
                }
        }

        ret = process_validate_vms(process_info, NULL);
        if (ret)
                goto unreserve_out;

        /* Validate BOs and update GPUVM page tables */
        list_for_each_entry_safe(mem, tmp_mem,
                                 &process_info->userptr_inval_list,
                                 validate_list) {
                struct kfd_mem_attachment *attachment;

                bo = mem->bo;

                /* Validate the BO if we got user pages */
                if (bo->tbo.ttm->pages[0]) {
                        amdgpu_bo_placement_from_domain(bo, mem->domain);
                        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
                        if (ret) {
                                pr_err("%s: failed to validate BO\n", __func__);
                                goto unreserve_out;
                        }
                }

                /* Update mapping. If the BO was not validated
                 * (because we couldn't get user pages), this will
                 * clear the page table entries, which will result in
                 * VM faults if the GPU tries to access the invalid
                 * memory.
                 */
                list_for_each_entry(attachment, &mem->attachments, list) {
                        if (!attachment->is_mapped)
                                continue;

                        kfd_mem_dmaunmap_attachment(mem, attachment);
                        ret = update_gpuvm_pte(mem, attachment, &sync);
                        if (ret) {
                                pr_err("%s: update PTE failed\n", __func__);
                                /* make sure this gets validated again */
                                mutex_lock(&process_info->notifier_lock);
                                mem->invalid++;
                                mutex_unlock(&process_info->notifier_lock);
                                goto unreserve_out;
                        }
                }
        }

        /* Update page directories */
        ret = process_update_pds(process_info, &sync);

unreserve_out:
        drm_exec_fini(&exec);
        amdgpu_sync_wait(&sync, false);
        amdgpu_sync_free(&sync);

        return ret;
}

/* Confirm that all user pages are valid while holding the notifier lock
 *
 * Moves valid BOs from the userptr_inval_list back to userptr_val_list.
 */
static int confirm_valid_user_pages_locked(struct amdkfd_process_info *process_info)
{
        struct kgd_mem *mem, *tmp_mem;
        int ret = 0;

        list_for_each_entry_safe(mem, tmp_mem,
                                 &process_info->userptr_inval_list,
                                 validate_list) {
                bool valid;

                /* keep mem without hmm range at userptr_inval_list */
                if (!mem->range)
                        continue;

                /* Only check mem with hmm range associated */
                valid = amdgpu_hmm_range_valid(mem->range);
                amdgpu_hmm_range_free(mem->range);

                mem->range = NULL;
                if (!valid) {
                        WARN(!mem->invalid, "Invalid BO not marked invalid");
                        ret = -EAGAIN;
                        continue;
                }

                if (mem->invalid) {
                        WARN(1, "Valid BO is marked invalid");
                        ret = -EAGAIN;
                        continue;
                }

                list_move_tail(&mem->validate_list,
                               &process_info->userptr_valid_list);
        }

        return ret;
}

/* Worker callback to restore evicted userptr BOs
 *
 * Tries to update and validate all userptr BOs. If successful and no
 * concurrent evictions happened, the queues are restarted. Otherwise,
 * reschedule for another attempt later.
 */
static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct amdkfd_process_info *process_info =
                container_of(dwork, struct amdkfd_process_info,
                             restore_userptr_work);
        struct task_struct *usertask;
        struct mm_struct *mm;
        uint32_t evicted_bos;

        mutex_lock(&process_info->notifier_lock);
        evicted_bos = process_info->evicted_bos;
        mutex_unlock(&process_info->notifier_lock);
        if (!evicted_bos)
                return;

        /* Reference task and mm in case of concurrent process termination */
        usertask = get_pid_task(process_info->pid, PIDTYPE_PID);
        if (!usertask)
                return;
        mm = get_task_mm(usertask);
        if (!mm) {
                put_task_struct(usertask);
                return;
        }

        mutex_lock(&process_info->lock);

        if (update_invalid_user_pages(process_info, mm))
                goto unlock_out;
        /* userptr_inval_list can be empty if all evicted userptr BOs
         * have been freed. In that case there is nothing to validate
         * and we can just restart the queues.
         */
        if (!list_empty(&process_info->userptr_inval_list)) {
                if (validate_invalid_user_pages(process_info))
                        goto unlock_out;
        }
        /* Final check for concurrent evicton and atomic update. If
         * another eviction happens after successful update, it will
         * be a first eviction that calls quiesce_mm. The eviction
         * reference counting inside KFD will handle this case.
         */
        mutex_lock(&process_info->notifier_lock);
        if (process_info->evicted_bos != evicted_bos)
                goto unlock_notifier_out;

        if (confirm_valid_user_pages_locked(process_info)) {
                WARN(1, "User pages unexpectedly invalid");
                goto unlock_notifier_out;
        }

        process_info->evicted_bos = evicted_bos = 0;

        if (kgd2kfd_resume_mm(mm)) {
                pr_err("%s: Failed to resume KFD\n", __func__);
                /* No recovery from this failure. Probably the CP is
                 * hanging. No point trying again.
                 */
        }

unlock_notifier_out:
        mutex_unlock(&process_info->notifier_lock);
unlock_out:
        mutex_unlock(&process_info->lock);

        /* If validation failed, reschedule another attempt */
        if (evicted_bos) {
                queue_delayed_work(system_freezable_wq,
                        &process_info->restore_userptr_work,
                        msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS));

                kfd_smi_event_queue_restore_rescheduled(mm);
        }
        mmput(mm);
        put_task_struct(usertask);
}

static void replace_eviction_fence(struct dma_fence __rcu **ef,
                                   struct dma_fence *new_ef)
{
        struct dma_fence *old_ef = rcu_replace_pointer(*ef, new_ef, true
                /* protected by process_info->lock */);

        /* If we're replacing an unsignaled eviction fence, that fence will
         * never be signaled, and if anyone is still waiting on that fence,
         * they will hang forever. This should never happen. We should only
         * replace the fence in restore_work that only gets scheduled after
         * eviction work signaled the fence.
         */
        WARN_ONCE(!dma_fence_is_signaled(old_ef),
                  "Replacing unsignaled eviction fence");
        dma_fence_put(old_ef);
}

/** amdgpu_amdkfd_gpuvm_restore_process_bos - Restore all BOs for the given
 *   KFD process identified by process_info
 *
 * @process_info: amdkfd_process_info of the KFD process
 *
 * After memory eviction, restore thread calls this function. The function
 * should be called when the Process is still valid. BO restore involves -
 *
 * 1.  Release old eviction fence and create new one
 * 2.  Get two copies of PD BO list from all the VMs. Keep one copy as pd_list.
 * 3   Use the second PD list and kfd_bo_list to create a list (ctx.list) of
 *     BOs that need to be reserved.
 * 4.  Reserve all the BOs
 * 5.  Validate of PD and PT BOs.
 * 6.  Validate all KFD BOs using kfd_bo_list and Map them and add new fence
 * 7.  Add fence to all PD and PT BOs.
 * 8.  Unreserve all BOs
 */
int amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct dma_fence __rcu **ef)
{
        struct amdkfd_process_info *process_info = info;
        struct amdgpu_vm *peer_vm;
        struct kgd_mem *mem;
        struct list_head duplicate_save;
        struct amdgpu_sync sync_obj;
        unsigned long failed_size = 0;
        unsigned long total_size = 0;
        struct drm_exec exec;
        int ret;

        INIT_LIST_HEAD(&duplicate_save);

        mutex_lock(&process_info->lock);

        drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
        drm_exec_until_all_locked(&exec) {
                list_for_each_entry(peer_vm, &process_info->vm_list_head,
                                    vm_list_node) {
                        ret = amdgpu_vm_lock_pd(peer_vm, &exec, 2);
                        drm_exec_retry_on_contention(&exec);
                        if (unlikely(ret)) {
                                pr_err("Locking VM PD failed, ret: %d\n", ret);
                                goto ttm_reserve_fail;
                        }
                }

                /* Reserve all BOs and page tables/directory. Add all BOs from
                 * kfd_bo_list to ctx.list
                 */
                list_for_each_entry(mem, &process_info->kfd_bo_list,
                                    validate_list) {
                        struct drm_gem_object *gobj;

                        gobj = &mem->bo->tbo.base;
                        ret = drm_exec_prepare_obj(&exec, gobj, 1);
                        drm_exec_retry_on_contention(&exec);
                        if (unlikely(ret)) {
                                pr_err("drm_exec_prepare_obj failed, ret: %d\n", ret);
                                goto ttm_reserve_fail;
                        }
                }
        }

        amdgpu_sync_create(&sync_obj);

        /* Validate BOs managed by KFD */
        list_for_each_entry(mem, &process_info->kfd_bo_list,
                            validate_list) {

                struct amdgpu_bo *bo = mem->bo;
                uint32_t domain = mem->domain;
                struct dma_resv_iter cursor;
                struct dma_fence *fence;

                total_size += amdgpu_bo_size(bo);

                ret = amdgpu_amdkfd_bo_validate(bo, domain, false);
                if (ret) {
                        pr_debug("Memory eviction: Validate BOs failed\n");
                        failed_size += amdgpu_bo_size(bo);
                        ret = amdgpu_amdkfd_bo_validate(bo,
                                                AMDGPU_GEM_DOMAIN_GTT, false);
                        if (ret) {
                                pr_debug("Memory eviction: Try again\n");
                                goto validate_map_fail;
                        }
                }
                dma_resv_for_each_fence(&cursor, bo->tbo.base.resv,
                                        DMA_RESV_USAGE_KERNEL, fence) {
                        ret = amdgpu_sync_fence(&sync_obj, fence, GFP_KERNEL);
                        if (ret) {
                                pr_debug("Memory eviction: Sync BO fence failed. Try again\n");
                                goto validate_map_fail;
                        }
                }
        }

        if (failed_size)
                pr_debug("0x%lx/0x%lx in system\n", failed_size, total_size);

        /* Validate PDs, PTs and evicted DMABuf imports last. Otherwise BO
         * validations above would invalidate DMABuf imports again.
         */
        ret = process_validate_vms(process_info, &exec.ticket);
        if (ret) {
                pr_debug("Validating VMs failed, ret: %d\n", ret);
                goto validate_map_fail;
        }

        /* Update mappings managed by KFD. */
        list_for_each_entry(mem, &process_info->kfd_bo_list,
                            validate_list) {
                struct kfd_mem_attachment *attachment;

                list_for_each_entry(attachment, &mem->attachments, list) {
                        if (!attachment->is_mapped)
                                continue;

                        kfd_mem_dmaunmap_attachment(mem, attachment);
                        ret = update_gpuvm_pte(mem, attachment, &sync_obj);
                        if (ret) {
                                pr_debug("Memory eviction: update PTE failed. Try again\n");
                                goto validate_map_fail;
                        }
                }
        }

        /* Update mappings not managed by KFD */
        list_for_each_entry(peer_vm, &process_info->vm_list_head,
                        vm_list_node) {
                struct amdgpu_device *adev = amdgpu_ttm_adev(
                        peer_vm->root.bo->tbo.bdev);

                struct amdgpu_fpriv *fpriv =
                        container_of(peer_vm, struct amdgpu_fpriv, vm);

                ret = amdgpu_vm_bo_update(adev, fpriv->prt_va, false);
                if (ret) {
                        dev_dbg(adev->dev,
                                "Memory eviction: handle PRT moved failed, pid %8d. Try again.\n",
                                pid_nr(process_info->pid));
                        goto validate_map_fail;
                }

                ret = amdgpu_vm_handle_moved(adev, peer_vm, &exec.ticket);
                if (ret) {
                        dev_dbg(adev->dev,
                                "Memory eviction: handle moved failed, pid %8d. Try again.\n",
                                pid_nr(process_info->pid));
                        goto validate_map_fail;
                }
        }

        /* Update page directories */
        ret = process_update_pds(process_info, &sync_obj);
        if (ret) {
                pr_debug("Memory eviction: update PDs failed. Try again\n");
                goto validate_map_fail;
        }

        /* Sync with fences on all the page tables. They implicitly depend on any
         * move fences from amdgpu_vm_handle_moved above.
         */
        ret = process_sync_pds_resv(process_info, &sync_obj);
        if (ret) {
                pr_debug("Memory eviction: Failed to sync to PD BO moving fence. Try again\n");
                goto validate_map_fail;
        }

        /* Wait for validate and PT updates to finish */
        amdgpu_sync_wait(&sync_obj, false);

        /* The old eviction fence may be unsignaled if restore happens
         * after a GPU reset or suspend/resume. Keep the old fence in that
         * case. Otherwise release the old eviction fence and create new
         * one, because fence only goes from unsignaled to signaled once
         * and cannot be reused. Use context and mm from the old fence.
         *
         * If an old eviction fence signals after this check, that's OK.
         * Anyone signaling an eviction fence must stop the queues first
         * and schedule another restore worker.
         */
        if (dma_fence_is_signaled(&process_info->eviction_fence->base)) {
                struct amdgpu_amdkfd_fence *new_fence =
                        amdgpu_amdkfd_fence_create(
                                process_info->eviction_fence->base.context,
                                process_info->eviction_fence->mm,
                                NULL, process_info->context_id);

                if (!new_fence) {
                        pr_err("Failed to create eviction fence\n");
                        ret = -ENOMEM;
                        goto validate_map_fail;
                }
                dma_fence_put(&process_info->eviction_fence->base);
                process_info->eviction_fence = new_fence;
                replace_eviction_fence(ef, dma_fence_get(&new_fence->base));
        } else {
                WARN_ONCE(*ef != &process_info->eviction_fence->base,
                          "KFD eviction fence doesn't match KGD process_info");
        }

        /* Attach new eviction fence to all BOs except pinned ones */
        list_for_each_entry(mem, &process_info->kfd_bo_list, validate_list) {
                if (mem->bo->tbo.pin_count)
                        continue;

                dma_resv_add_fence(mem->bo->tbo.base.resv,
                                   &process_info->eviction_fence->base,
                                   DMA_RESV_USAGE_BOOKKEEP);
        }
        /* Attach eviction fence to PD / PT BOs and DMABuf imports */
        list_for_each_entry(peer_vm, &process_info->vm_list_head,
                            vm_list_node) {
                struct amdgpu_bo *bo = peer_vm->root.bo;

                dma_resv_add_fence(bo->tbo.base.resv,
                                   &process_info->eviction_fence->base,
                                   DMA_RESV_USAGE_BOOKKEEP);
        }

validate_map_fail:
        amdgpu_sync_free(&sync_obj);
ttm_reserve_fail:
        drm_exec_fini(&exec);
        mutex_unlock(&process_info->lock);
        return ret;
}

int amdgpu_amdkfd_add_gws_to_process(void *info, void *gws, struct kgd_mem **mem)
{
        struct amdkfd_process_info *process_info = (struct amdkfd_process_info *)info;
        struct amdgpu_bo *gws_bo = (struct amdgpu_bo *)gws;
        int ret;

        if (!info || !gws)
                return -EINVAL;

        *mem = kzalloc_obj(struct kgd_mem);
        if (!*mem)
                return -ENOMEM;

        mutex_init(&(*mem)->lock);
        INIT_LIST_HEAD(&(*mem)->attachments);
        (*mem)->bo = amdgpu_bo_ref(gws_bo);
        (*mem)->domain = AMDGPU_GEM_DOMAIN_GWS;
        (*mem)->process_info = process_info;
        add_kgd_mem_to_kfd_bo_list(*mem, process_info, false);
        amdgpu_sync_create(&(*mem)->sync);


        /* Validate gws bo the first time it is added to process */
        mutex_lock(&(*mem)->process_info->lock);
        ret = amdgpu_bo_reserve(gws_bo, false);
        if (unlikely(ret)) {
                pr_err("Reserve gws bo failed %d\n", ret);
                goto bo_reservation_failure;
        }

        ret = amdgpu_amdkfd_bo_validate(gws_bo, AMDGPU_GEM_DOMAIN_GWS, true);
        if (ret) {
                pr_err("GWS BO validate failed %d\n", ret);
                goto bo_validation_failure;
        }
        /* GWS resource is shared b/t amdgpu and amdkfd
         * Add process eviction fence to bo so they can
         * evict each other.
         */
        ret = dma_resv_reserve_fences(gws_bo->tbo.base.resv, 1);
        if (ret)
                goto reserve_shared_fail;
        dma_resv_add_fence(gws_bo->tbo.base.resv,
                           &process_info->eviction_fence->base,
                           DMA_RESV_USAGE_BOOKKEEP);
        amdgpu_bo_unreserve(gws_bo);
        mutex_unlock(&(*mem)->process_info->lock);

        return ret;

reserve_shared_fail:
bo_validation_failure:
        amdgpu_bo_unreserve(gws_bo);
bo_reservation_failure:
        mutex_unlock(&(*mem)->process_info->lock);
        amdgpu_sync_free(&(*mem)->sync);
        remove_kgd_mem_from_kfd_bo_list(*mem, process_info);
        amdgpu_bo_unref(&gws_bo);
        mutex_destroy(&(*mem)->lock);
        kfree(*mem);
        *mem = NULL;
        return ret;
}

int amdgpu_amdkfd_remove_gws_from_process(void *info, void *mem)
{
        int ret;
        struct amdkfd_process_info *process_info = (struct amdkfd_process_info *)info;
        struct kgd_mem *kgd_mem = (struct kgd_mem *)mem;
        struct amdgpu_bo *gws_bo = kgd_mem->bo;

        /* Remove BO from process's validate list so restore worker won't touch
         * it anymore
         */
        remove_kgd_mem_from_kfd_bo_list(kgd_mem, process_info);

        ret = amdgpu_bo_reserve(gws_bo, false);
        if (unlikely(ret)) {
                pr_err("Reserve gws bo failed %d\n", ret);
                //TODO add BO back to validate_list?
                return ret;
        }
        amdgpu_amdkfd_remove_eviction_fence(gws_bo,
                        process_info->eviction_fence);
        amdgpu_bo_unreserve(gws_bo);
        amdgpu_sync_free(&kgd_mem->sync);
        amdgpu_bo_unref(&gws_bo);
        mutex_destroy(&kgd_mem->lock);
        kfree(mem);
        return 0;
}

/* Returns GPU-specific tiling mode information */
int amdgpu_amdkfd_get_tile_config(struct amdgpu_device *adev,
                                struct tile_config *config)
{
        config->gb_addr_config = adev->gfx.config.gb_addr_config;
        config->tile_config_ptr = adev->gfx.config.tile_mode_array;
        config->num_tile_configs =
                        ARRAY_SIZE(adev->gfx.config.tile_mode_array);
        config->macro_tile_config_ptr =
                        adev->gfx.config.macrotile_mode_array;
        config->num_macro_tile_configs =
                        ARRAY_SIZE(adev->gfx.config.macrotile_mode_array);

        /* Those values are not set from GFX9 onwards */
        config->num_banks = adev->gfx.config.num_banks;
        config->num_ranks = adev->gfx.config.num_ranks;

        return 0;
}

bool amdgpu_amdkfd_bo_mapped_to_dev(void *drm_priv, struct kgd_mem *mem)
{
        struct amdgpu_vm *vm = drm_priv_to_vm(drm_priv);
        struct kfd_mem_attachment *entry;

        list_for_each_entry(entry, &mem->attachments, list) {
                if (entry->is_mapped && entry->bo_va->base.vm == vm)
                        return true;
        }
        return false;
}

#if defined(CONFIG_DEBUG_FS)

int kfd_debugfs_kfd_mem_limits(struct seq_file *m, void *data)
{

        spin_lock(&kfd_mem_limit.mem_limit_lock);
        seq_printf(m, "System mem used %lldM out of %lluM\n",
                  (kfd_mem_limit.system_mem_used >> 20),
                  (kfd_mem_limit.max_system_mem_limit >> 20));
        seq_printf(m, "TTM mem used %lldM out of %lluM\n",
                  (kfd_mem_limit.ttm_mem_used >> 20),
                  (kfd_mem_limit.max_ttm_mem_limit >> 20));
        spin_unlock(&kfd_mem_limit.mem_limit_lock);

        return 0;
}

#endif