/*******************************************************************************
    Copyright (c) 2018-2023 NVIDIA Corporation

    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
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    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.

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    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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    DEALINGS IN THE SOFTWARE.

*******************************************************************************/

#ifndef __UVM_ATS_SVA_H__
#define __UVM_ATS_SVA_H__

#include "uvm_gpu.h"
#include "uvm_forward_decl.h"

#include <linux/iommu.h>

// For ATS support on aarch64, arm_smmu_sva_bind() is needed for
// iommu_sva_bind_device() calls. Unfortunately, arm_smmu_sva_bind() is not
// conftest-able. We instead look for the presence of ioasid_get() or
// mm_pasid_drop(). ioasid_get() was added in the same patch series as
// arm_smmu_sva_bind() and removed in v6.0. mm_pasid_drop() was added in the
// same patch as the removal of ioasid_get(). We assume the presence of
// arm_smmu_sva_bind() if ioasid_get(v5.11 - v5.17) or mm_pasid_drop(v5.18+) is
// present.
//
// arm_smmu_sva_bind() was added with commit
// 32784a9562fb0518b12e9797ee2aec52214adf6f and ioasid_get() was added with
// commit cb4789b0d19ff231ce9f73376a023341300aed96 (11/23/2020). Commit
// 701fac40384f07197b106136012804c3cae0b3de (02/15/2022) removed ioasid_get()
// and added mm_pasid_drop().
    #define UVM_ATS_SVA_SUPPORTED() 0

// If NV_MMU_NOTIFIER_OPS_HAS_ARCH_INVALIDATE_SECONDARY_TLBS is defined it
// means the upstream fix is in place so no need for the WAR from
// Bug 4130089: [GH180][r535] WAR for  kernel not issuing SMMU TLB
// invalidates on read-only
#if defined(NV_MMU_NOTIFIER_OPS_HAS_ARCH_INVALIDATE_SECONDARY_TLBS)
    #define UVM_ATS_SMMU_WAR_REQUIRED() 0
#elif NVCPU_IS_AARCH64
    #define UVM_ATS_SMMU_WAR_REQUIRED() 1
#else
    #define UVM_ATS_SMMU_WAR_REQUIRED() 0
#endif

typedef struct
{
    int placeholder;
} uvm_sva_va_space_t;

typedef struct
{
    // Reference count for the iommu_handle
    nv_kref_t kref;
    struct iommu_sva *iommu_handle;
} uvm_sva_gpu_va_space_t;

#if UVM_ATS_SVA_SUPPORTED()
    NV_STATUS uvm_ats_sva_add_gpu(uvm_parent_gpu_t *parent_gpu);
    void uvm_ats_sva_remove_gpu(uvm_parent_gpu_t *parent_gpu);

    // LOCKING: mmap_lock must be lockable
    //          VA space lock must not be held.
    NV_STATUS uvm_ats_sva_bind_gpu(uvm_gpu_va_space_t *gpu_va_space);

    // LOCKING: VA space lock must not be held.
    void uvm_ats_sva_unbind_gpu(uvm_gpu_va_space_t *gpu_va_space);

    // LOCKING: None
    NV_STATUS uvm_ats_sva_register_gpu_va_space(uvm_gpu_va_space_t *gpu_va_space);

    // LOCKING: None
    void uvm_ats_sva_unregister_gpu_va_space(uvm_gpu_va_space_t *gpu_va_space);

    // Fix for Bug 4130089: [GH180][r535] WAR for kernel not issuing SMMU
    // TLB invalidates on read-only to read-write upgrades
    #if UVM_ATS_SMMU_WAR_REQUIRED()
        void uvm_ats_smmu_invalidate_tlbs(uvm_gpu_va_space_t *gpu_va_space, NvU64 addr, size_t size);
    #else
        static void uvm_ats_smmu_invalidate_tlbs(uvm_gpu_va_space_t *gpu_va_space, NvU64 addr, size_t size)
        {

        }
    #endif
#else
    static NV_STATUS uvm_ats_sva_add_gpu(uvm_parent_gpu_t *parent_gpu)
    {
        return NV_OK;
    }

    static void uvm_ats_sva_remove_gpu(uvm_parent_gpu_t *parent_gpu)
    {

    }

    static NV_STATUS uvm_ats_sva_bind_gpu(uvm_gpu_va_space_t *gpu_va_space)
    {
        return NV_OK;
    }

    static void uvm_ats_sva_unbind_gpu(uvm_gpu_va_space_t *gpu_va_space)
    {

    }

    static NV_STATUS uvm_ats_sva_register_gpu_va_space(uvm_gpu_va_space_t *gpu_va_space)
    {
        return NV_OK;
    }

    static void uvm_ats_sva_unregister_gpu_va_space(uvm_gpu_va_space_t *gpu_va_space)
    {

    }

    static void uvm_ats_smmu_invalidate_tlbs(uvm_gpu_va_space_t *gpu_va_space, NvU64 addr, size_t size)
    {

    }
#endif // UVM_ATS_SVA_SUPPORTED

#endif // __UVM_ATS_SVA_H__
