/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/*
 * Copyright 2020-2021 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.
 *
 */

#ifndef KFD_SVM_H_
#define KFD_SVM_H_

#if IS_ENABLED(CONFIG_HSA_AMD_SVM)

#include <linux/rwsem.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/sched/mm.h>
#include <linux/hmm.h>
#include "amdgpu.h"
#include "kfd_priv.h"

#define SVM_RANGE_VRAM_DOMAIN (1UL << 0)
#define SVM_ADEV_PGMAP_OWNER(adev)\
                        ((adev)->hive ? (void *)(adev)->hive : (void *)(adev))

struct svm_range_bo {
        struct amdgpu_bo                *bo;
        struct kref                     kref;
        struct list_head                range_list; /* all svm ranges shared this bo */
        spinlock_t                      list_lock;
        struct amdgpu_amdkfd_fence      *eviction_fence;
        struct work_struct              eviction_work;
        struct svm_range_list           *svms;
        uint32_t                        evicting;
        struct work_struct              release_work;
};

enum svm_work_list_ops {
        SVM_OP_NULL,
        SVM_OP_UNMAP_RANGE,
        SVM_OP_UPDATE_RANGE_NOTIFIER,
        SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP,
        SVM_OP_ADD_RANGE,
        SVM_OP_ADD_RANGE_AND_MAP
};

struct svm_work_list_item {
        enum svm_work_list_ops op;
        struct mm_struct *mm;
};

/**
 * struct svm_range - shared virtual memory range
 *
 * @svms:       list of svm ranges, structure defined in kfd_process
 * @migrate_mutex: to serialize range migration, validation and mapping update
 * @start:      range start address in pages
 * @last:       range last address in pages
 * @it_node:    node [start, last] stored in interval tree, start, last are page
 *              aligned, page size is (last - start + 1)
 * @list:       link list node, used to scan all ranges of svms
 * @update_list:link list node used to add to update_list
 * @mapping:    bo_va mapping structure to create and update GPU page table
 * @npages:     number of pages
 * @dma_addr:   dma mapping address on each GPU for system memory physical page
 * @ttm_res:    vram ttm resource map
 * @offset:     range start offset within mm_nodes
 * @svm_bo:     struct to manage splited amdgpu_bo
 * @svm_bo_list:link list node, to scan all ranges which share same svm_bo
 * @lock:       protect prange start, last, child_list, svm_bo_list
 * @saved_flags:save/restore current PF_MEMALLOC flags
 * @flags:      flags defined as KFD_IOCTL_SVM_FLAG_*
 * @perferred_loc: perferred location, 0 for CPU, or GPU id
 * @perfetch_loc: last prefetch location, 0 for CPU, or GPU id
 * @actual_loc: the actual location, 0 for CPU, or GPU id
 * @granularity:migration granularity, log2 num pages
 * @invalid:    not 0 means cpu page table is invalidated
 * @validate_timestamp: system timestamp when range is validated
 * @notifier:   register mmu interval notifier
 * @work_item:  deferred work item information
 * @deferred_list: list header used to add range to deferred list
 * @child_list: list header for split ranges which are not added to svms yet
 * @bitmap_access: index bitmap of GPUs which can access the range
 * @bitmap_aip: index bitmap of GPUs which can access the range in place
 *
 * Data structure for virtual memory range shared by CPU and GPUs, it can be
 * allocated from system memory ram or device vram, and migrate from ram to vram
 * or from vram to ram.
 */
struct svm_range {
        struct svm_range_list           *svms;
        struct mutex                    migrate_mutex;
        unsigned long                   start;
        unsigned long                   last;
        struct interval_tree_node       it_node;
        struct list_head                list;
        struct list_head                update_list;
        uint64_t                        npages;
        dma_addr_t                      *dma_addr[MAX_GPU_INSTANCE];
        struct ttm_resource             *ttm_res;
        uint64_t                        offset;
        struct svm_range_bo             *svm_bo;
        struct list_head                svm_bo_list;
        struct mutex                    lock;
        unsigned int                    saved_flags;
        uint32_t                        flags;
        uint32_t                        preferred_loc;
        uint32_t                        prefetch_loc;
        uint32_t                        actual_loc;
        uint8_t                         granularity;
        atomic_t                        invalid;
        uint64_t                        validate_timestamp;
        struct mmu_interval_notifier    notifier;
        struct svm_work_list_item       work_item;
        struct list_head                deferred_list;
        struct list_head                child_list;
        DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
        DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
        bool                            validated_once;
};

static inline void svm_range_lock(struct svm_range *prange)
{
        mutex_lock(&prange->lock);
        prange->saved_flags = memalloc_noreclaim_save();

}
static inline void svm_range_unlock(struct svm_range *prange)
{
        memalloc_noreclaim_restore(prange->saved_flags);
        mutex_unlock(&prange->lock);
}

static inline struct svm_range_bo *svm_range_bo_ref(struct svm_range_bo *svm_bo)
{
        if (svm_bo)
                kref_get(&svm_bo->kref);

        return svm_bo;
}

int svm_range_list_init(struct kfd_process *p);
void svm_range_list_fini(struct kfd_process *p);
int svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
              uint64_t size, uint32_t nattrs,
              struct kfd_ioctl_svm_attribute *attrs);
struct svm_range *svm_range_from_addr(struct svm_range_list *svms,
                                      unsigned long addr,
                                      struct svm_range **parent);
struct amdgpu_device *svm_range_get_adev_by_id(struct svm_range *prange,
                                               uint32_t id);
int svm_range_vram_node_new(struct amdgpu_device *adev,
                            struct svm_range *prange, bool clear);
void svm_range_vram_node_free(struct svm_range *prange);
int svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
                               unsigned long addr, struct svm_range *parent,
                               struct svm_range *prange);
int svm_range_restore_pages(struct amdgpu_device *adev,
                            unsigned int pasid, uint64_t addr, bool write_fault);
int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence);
void svm_range_add_list_work(struct svm_range_list *svms,
                             struct svm_range *prange, struct mm_struct *mm,
                             enum svm_work_list_ops op);
void schedule_deferred_list_work(struct svm_range_list *svms);
void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
                         unsigned long offset, unsigned long npages);
void svm_range_free_dma_mappings(struct svm_range *prange);
void svm_range_prefault(struct svm_range *prange, struct mm_struct *mm,
                        void *owner);
int svm_range_get_info(struct kfd_process *p, uint32_t *num_svm_ranges,
                       uint64_t *svm_priv_data_size);
int kfd_criu_checkpoint_svm(struct kfd_process *p,
                            uint8_t __user *user_priv_data,
                            uint64_t *priv_offset);
int kfd_criu_restore_svm(struct kfd_process *p,
                         uint8_t __user *user_priv_ptr,
                         uint64_t *priv_data_offset,
                         uint64_t max_priv_data_size);
int kfd_criu_resume_svm(struct kfd_process *p);
struct kfd_process_device *
svm_range_get_pdd_by_adev(struct svm_range *prange, struct amdgpu_device *adev);
void svm_range_list_lock_and_flush_work(struct svm_range_list *svms, struct mm_struct *mm);

/* SVM API and HMM page migration work together, device memory type
 * is initialized to not 0 when page migration register device memory.
 */
#define KFD_IS_SVM_API_SUPPORTED(dev) ((dev)->pgmap.type != 0)

void svm_range_bo_unref_async(struct svm_range_bo *svm_bo);
#else

struct kfd_process;

static inline int svm_range_list_init(struct kfd_process *p)
{
        return 0;
}
static inline void svm_range_list_fini(struct kfd_process *p)
{
        /* empty */
}

static inline int svm_range_restore_pages(struct amdgpu_device *adev,
                                          unsigned int pasid, uint64_t addr,
                                          bool write_fault)
{
        return -EFAULT;
}

static inline int svm_range_schedule_evict_svm_bo(
                struct amdgpu_amdkfd_fence *fence)
{
        WARN_ONCE(1, "SVM eviction fence triggered, but SVM is disabled");
        return -EINVAL;
}

static inline int svm_range_get_info(struct kfd_process *p,
                                     uint32_t *num_svm_ranges,
                                     uint64_t *svm_priv_data_size)
{
        *num_svm_ranges = 0;
        *svm_priv_data_size = 0;
        return 0;
}

static inline int kfd_criu_checkpoint_svm(struct kfd_process *p,
                                          uint8_t __user *user_priv_data,
                                          uint64_t *priv_offset)
{
        return 0;
}

static inline int kfd_criu_restore_svm(struct kfd_process *p,
                                       uint8_t __user *user_priv_ptr,
                                       uint64_t *priv_data_offset,
                                       uint64_t max_priv_data_size)
{
        return -EINVAL;
}

static inline int kfd_criu_resume_svm(struct kfd_process *p)
{
        return 0;
}

#define KFD_IS_SVM_API_SUPPORTED(dev) false

#endif /* IS_ENABLED(CONFIG_HSA_AMD_SVM) */

#endif /* KFD_SVM_H_ */