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

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    Copyright (c) 2016 NVIDIA Corporation

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#ifndef __UVM_MAP_EXTERNAL_H__
#define __UVM_MAP_EXTERNAL_H__

#include "uvm_forward_decl.h"
#include "uvm_va_range.h"
#include "uvm_tracker.h"
#include "nv_uvm_types.h"
#include "uvm_types.h"

typedef struct
{
    NvU64 map_offset;
    UvmGpuMappingType mapping_type;
    UvmGpuCachingType caching_type;
    UvmGpuFormatType format_type;
    UvmGpuFormatElementBits element_bits;
    UvmGpuCompressionType compression_type;
} uvm_map_rm_params_t;

static uvm_ext_gpu_range_tree_t *uvm_ext_gpu_range_tree(uvm_va_range_t *va_range, uvm_gpu_t *gpu)
{
    UVM_ASSERT(va_range->type == UVM_VA_RANGE_TYPE_EXTERNAL);

    return &va_range->external.gpu_ranges[uvm_id_gpu_index(gpu->id)];
}

// Returns the first external map (if any) in the gpu's range tree.
// va_range should be of type UVM_VA_RANGE_TYPE_EXTERNAL.
// The caller must hold the range tree lock.
static uvm_ext_gpu_map_t *uvm_ext_gpu_map_iter_first(uvm_va_range_t *va_range, uvm_gpu_t *gpu, NvU64 start, NvU64 end)
{
    uvm_ext_gpu_range_tree_t *range_tree;
    uvm_range_tree_node_t *node;

    UVM_ASSERT(start >= va_range->node.start);
    UVM_ASSERT(end <= va_range->node.end);

    range_tree = uvm_ext_gpu_range_tree(va_range, gpu);
    node = uvm_range_tree_iter_first(&range_tree->tree, start, end);
    return uvm_ext_gpu_map_container(node);
}

// Returns the external map following the provided map (if any) in address order from
// the gpu's range tree. va_range should be of type UVM_VA_RANGE_TYPE_EXTERNAL.
// The caller must hold the range tree lock.
static uvm_ext_gpu_map_t *uvm_ext_gpu_map_iter_next(uvm_va_range_t *va_range, uvm_ext_gpu_map_t *ext_gpu_map, NvU64 end)
{
    uvm_ext_gpu_range_tree_t *range_tree;
    uvm_range_tree_node_t *node;

    if (!ext_gpu_map)
        return NULL;

    UVM_ASSERT(end <= va_range->node.end);

    range_tree = uvm_ext_gpu_range_tree(va_range, ext_gpu_map->gpu);
    node = uvm_range_tree_iter_next(&range_tree->tree, &ext_gpu_map->node, end);
    return uvm_ext_gpu_map_container(node);
}

// The four iterators below require that the caller hold the gpu's range tree
// lock.
#define uvm_ext_gpu_map_for_each_in(ext_gpu_map, va_range, gpu, start, end)             \
    for ((ext_gpu_map) = uvm_ext_gpu_map_iter_first((va_range), (gpu), (start), (end)); \
         (ext_gpu_map);                                                                 \
         (ext_gpu_map) = uvm_ext_gpu_map_iter_next((va_range), (ext_gpu_map), (end)))

#define uvm_ext_gpu_map_for_each_in_safe(ext_gpu_map, ext_gpu_map_next, va_range, gpu, start, end) \
    for ((ext_gpu_map) = uvm_ext_gpu_map_iter_first((va_range), (gpu), (start), (end)),            \
             (ext_gpu_map_next) = uvm_ext_gpu_map_iter_next((va_range), (ext_gpu_map), (end));     \
         (ext_gpu_map);                                                                            \
         (ext_gpu_map) = (ext_gpu_map_next),                                                       \
             (ext_gpu_map_next) = uvm_ext_gpu_map_iter_next((va_range), (ext_gpu_map), (end)))

#define uvm_ext_gpu_map_for_each(ext_gpu_map, va_range, gpu) \
    uvm_ext_gpu_map_for_each_in(ext_gpu_map, va_range, gpu, (va_range)->node.start, (va_range)->node.end)

#define uvm_ext_gpu_map_for_each_safe(ext_gpu_map, ext_gpu_map_next, va_range, gpu) \
    uvm_ext_gpu_map_for_each_in_safe(ext_gpu_map,                                   \
                                     ext_gpu_map_next,                              \
                                     va_range,                                      \
                                     gpu,                                           \
                                     (va_range)->node.start,                        \
                                     (va_range)->node.end)

// User-facing APIs (uvm_api_map_external_allocation, uvm_api_free) are declared
// uvm_api.h.

// Queries RM for the PTEs appropriate to the VA range and mem_info, allocates
// page tables for the VA range, and writes the PTEs.
//
// va_range must have type UVM_VA_RANGE_TYPE_EXTERNAL or
// UVM_VA_RANGE_TYPE_CHANNEL. The allocation descriptor given to RM is looked up
// depending on the type of the va_range.
// For va_ranges of type UVM_VA_RANGE_TYPE_CHANNEL, the descriptor is looked up
// from the va_range. In these cases, the ext_gpu_map parameter should be NULL.
// For va_ranges of type UVM_VA_RANGE_TYPE_EXTERNAL, it is looked up from the
// ext_gpu_map parameter.
//
// This does not wait for the PTE writes to complete. The work is added to
// the output tracker.
NV_STATUS uvm_va_range_map_rm_allocation(uvm_va_range_t *va_range,
                                         uvm_gpu_t *mapping_gpu,
                                         const UvmGpuMemoryInfo *mem_info,
                                         const uvm_map_rm_params_t *map_rm_params,
                                         uvm_ext_gpu_map_t *ext_gpu_map,
                                         uvm_tracker_t *out_tracker);

// Removes and frees the external mapping for mapping_gpu from ext_gpu_map
// mapped within va_range. If deferred_free_list is NULL, the RM handle is freed
// immediately by this function. Otherwise the GPU which owns the allocation (if
// any) is retained and the handle is added to the list for later processing by
// uvm_deferred_free_object_list.
//
// If the mapping is a Sparse mapping, the mapping is removed and freed.
// However, since sparse mappings do not have RM handles, nothing is added to
// the deferred_free_list (if not NULL) and the GPU is no retained.
//
// The caller must hold the range tree lock for the mapping gpu and is
// responsible for making sure that mapping gpu is retained across those calls.
void uvm_ext_gpu_map_destroy(uvm_va_range_t *va_range,
                             uvm_ext_gpu_map_t *ext_gpu_map,
                             struct list_head *deferred_free_list);

// Deferred free function which frees the RM handle and the object itself.
void uvm_ext_gpu_map_free(uvm_ext_gpu_map_t *ext_gpu_map);

#endif // __UVM_MAP_EXTERNAL_H__