zircon/kernel/vm/include/vm/bootreserve.h

// Copyright 2018 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#pragma once

#include <fbl/function.h>
#include <sys/types.h>
#include <zircon/types.h>

// The boot memory reservation system is a one-use early boot mechanism for
// a platform to mark certain ranges of physical space as occupied by something
// prior to adding arenas to the PMM.
//
// boot_reserve_init() must be called before adding the first pmm arena and
// boot_reserve_wire() should be called after the last arena is added to mark
// pages the reserved ranges intersect as WIRED.
//
// As the PMM arenas are added, the boot reserved ranges are consulted to make
// sure the pmm data structures do not overlap with any reserved ranges.

void boot_reserve_init();
void boot_reserve_wire();

zx_status_t boot_reserve_add_range(paddr_t pa, size_t len);

typedef struct {
    paddr_t pa;
    size_t len;
} reserve_range_t;

// Given a range, allocate a subrange within it of size alloc_len that does not intersect with
// any previously reserved ranges.
// Allocated range is upper aligned, starting with the highest base address to
// satisfy the requirements.
// Used by the PMM arena initialization code to allocate memory for itself.
zx_status_t boot_reserve_range_search(paddr_t range_pa, size_t range_len, size_t alloc_len,
                                      reserve_range_t* alloc_range);


// Call |cb| for each reserve range registered. Exit if the callback returns false. This
// function does not lock the region structure.
//
// Returns the same value the callback |cb| returns.
bool boot_reserve_foreach(const fbl::Function<bool(reserve_range_t)>& cb);

// Unwires |page| and leaves it in an ALLOC state.
void boot_reserve_unwire_page(struct vm_page* page);