nvidia-open-gpu-kernel-modules/kernel-open/nvidia-uvm/uvm_ats.h

/*******************************************************************************
    Copyright (c) 2018-2021 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
    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 AUTHORS OR COPYRIGHT HOLDERS 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 __UVM_ATS_H__
#define __UVM_ATS_H__

#include "uvm_linux.h"
#include "uvm_forward_decl.h"
#include "uvm_ats_ibm.h"
#include "nv_uvm_types.h"
#include "uvm_lock.h"

    #include "uvm_ats_sva.h"

    #define UVM_ATS_SUPPORTED() (UVM_ATS_IBM_SUPPORTED() || UVM_ATS_SVA_SUPPORTED())

typedef struct
{
    // Mask of gpu_va_spaces which are registered for ATS access. The mask is
    // indexed by gpu->id. This mask is protected by the VA space lock.
    uvm_processor_mask_t registered_gpu_va_spaces;

    // Protects racing invalidates in the VA space while hmm_range_fault() is
    // being called in ats_compute_residency_mask().
    uvm_rw_semaphore_t lock;

    union
    {
        uvm_ibm_va_space_t ibm;

        uvm_sva_va_space_t sva;
    };
} uvm_ats_va_space_t;

typedef struct
{
    // Each GPU VA space can have ATS enabled or disabled in its hardware
    // state. This is controlled by user space when it allocates that GPU VA
    // space object from RM. This flag indicates the mode user space
    // requested when allocating this GPU VA space.
    bool enabled;

    NvU32 pasid;

    union
    {
        uvm_ibm_gpu_va_space_t ibm;

        uvm_sva_gpu_va_space_t sva;
    };
} uvm_ats_gpu_va_space_t;

// Initializes driver-wide ATS state
//
// LOCKING: None
void uvm_ats_init(const UvmPlatformInfo *platform_info);

// Initializes ATS specific GPU state
//
// LOCKING: None
void uvm_ats_init_va_space(uvm_va_space_t *va_space);

// Enables ATS feature on the GPU.
//
// LOCKING: g_uvm_global.global lock mutex must be held.
NV_STATUS uvm_ats_add_gpu(uvm_parent_gpu_t *parent_gpu);

// Disables ATS feature on the GPU. The caller is responsible for ensuring
// that the GPU won't issue ATS requests anymore prior to calling this function.
//
// LOCKING: g_uvm_global.global lock mutex must be held.
void uvm_ats_remove_gpu(uvm_parent_gpu_t *parent_gpu);

// Creates a binding on the GPU for the mm associated with the VA space
// (va_space_mm). Multiple calls to this function are tracked and refcounted for
// the specific {gpu, mm} pair. A successful uvm_ats_add_gpu() must precede a
// call to this function.
//
// LOCKING: mmap_lock must be lockable.
//          VA space lock must be lockable.
//          gpu_va_space->gpu must be retained.
//          mm must be retained with uvm_va_space_mm_retain() iff
//          UVM_ATS_SVA_SUPPORTED() is 1
NV_STATUS uvm_ats_bind_gpu(uvm_gpu_va_space_t *gpu_va_space);

// Decrements the refcount on the {gpu, mm} pair. Removes the binding from the
// mm (va_space_mm) to this GPU when the refcount reaches zero.
//
// LOCKING: None
void uvm_ats_unbind_gpu(uvm_gpu_va_space_t *gpu_va_space);

// Enables ATS access on the GPU for the mm_struct associated with the VA space
// (va_space_mm) and assigns a PASID. A successful uvm_ats_bind_gpu() must
// precede a call to this function. Returns NV_ERR_INVALID_DEVICE if the
// gpu_va_space is already registered for ATS access.
//
// LOCKING: The VA space lock must be held in write mode.
//          mm has to be retained prior to calling this function.
//          current->mm->mmap_lock must be held in write mode iff
//          UVM_ATS_IBM_SUPPORTED_IN_KERNEL() is 1.
NV_STATUS uvm_ats_register_gpu_va_space(uvm_gpu_va_space_t *gpu_va_space);

// Disables ATS access for the gpu_va_space. Prior to calling this function,
// the caller must guarantee that the GPU will no longer make any ATS
// accesses in this GPU VA space, and that no ATS fault handling for this
// GPU will be attempted.
//
// LOCKING: This function may block on mmap_lock and will acquire the VA space
// lock, so neither lock must be held.
void uvm_ats_unregister_gpu_va_space(uvm_gpu_va_space_t *gpu_va_space);

// Synchronously invalidate ATS translations cached by GPU TLBs. The
// invalidate applies to all GPUs with active GPU VA spaces in va_space, and
// covers all pages touching any part of the given range. end is inclusive.
//
// GMMU translations in the given range are not guaranteed to be
// invalidated.
//
// LOCKING: No locks are required, but this function may be called with
//          interrupts disabled.
void uvm_ats_invalidate(uvm_va_space_t *va_space, NvU64 start, NvU64 end);

#endif // __UVM_ATS_H__