text: /* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
  #ifndef LIBFDT_INTERNAL_H
  #define LIBFDT_INTERNAL_H
  /*
   * libfdt - Flat Device Tree manipulation
   * Copyright (C) 2006 David Gibson, IBM Corporation.
   */
  #include <fdt.h>
  
  #define FDT_ALIGN(x, a)		(((x) + (a) - 1) & ~((a) - 1))
  #define FDT_TAGALIGN(x)		(FDT_ALIGN((x), FDT_TAGSIZE))
  
  int32_t fdt_ro_probe_(const void *fdt);
  #define FDT_RO_PROBE(fdt)					\
  	{							\
  		int32_t totalsize_;				\
  		if ((totalsize_ = fdt_ro_probe_(fdt)) < 0)	\
  			return totalsize_;			\
  	}
  
  int fdt_check_node_offset_(const void *fdt, int offset);
  int fdt_check_prop_offset_(const void *fdt, int offset);
  const char *fdt_find_string_(const char *strtab, int tabsize, const char *s);
  int fdt_node_end_offset_(void *fdt, int nodeoffset);
  
  static inline const void *fdt_offset_ptr_(const void *fdt, int offset)
  {
  	return (const char *)fdt + fdt_off_dt_struct(fdt) + offset;
  }
  
  static inline void *fdt_offset_ptr_w_(void *fdt, int offset)
  {
  	return (void *)(uintptr_t)fdt_offset_ptr_(fdt, offset);
  }
  
  static inline const struct fdt_reserve_entry *fdt_mem_rsv_(const void *fdt, int n)
  {
  	const struct fdt_reserve_entry *rsv_table =
  		(const struct fdt_reserve_entry *)
  		((const char *)fdt + fdt_off_mem_rsvmap(fdt));
  
  	return rsv_table + n;
  }
  static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n)
  {
  	return (void *)(uintptr_t)fdt_mem_rsv_(fdt, n);
  }
  
  #define FDT_SW_MAGIC		(~FDT_MAGIC)
  
  /**********************************************************************/
  /* Checking controls                                                  */
  /**********************************************************************/
  
  #ifndef FDT_ASSUME_MASK
  #define FDT_ASSUME_MASK 0
  #endif
  
  /*
   * Defines assumptions which can be enabled. Each of these can be enabled
   * individually. For maximum safety, don't enable any assumptions!
   *
   * For minimal code size and no safety, use ASSUME_PERFECT at your own risk.
   * You should have another method of validating the device tree, such as a
   * signature or hash check before using libfdt.
   *
   * For situations where security is not a concern it may be safe to enable
   * ASSUME_SANE.
   */
  enum {
  	/*
  	 * This does essentially no checks. Only the latest device-tree
  	 * version is correctly handled. Inconsistencies or errors in the device
  	 * tree may cause undefined behaviour or crashes. Invalid parameters
  	 * passed to libfdt may do the same.
  	 *
  	 * If an error occurs when modifying the tree it may leave the tree in
  	 * an intermediate (but valid) state. As an example, adding a property
  	 * where there is insufficient space may result in the property name
  	 * being added to the string table even though the property itself is
  	 * not added to the struct section.
  	 *
  	 * Only use this if you have a fully validated device tree with
  	 * the latest supported version and wish to minimise code size.
  	 */
  	ASSUME_PERFECT		= 0xff,
  
  	/*
  	 * This assumes that the device tree is sane. i.e. header metadata
  	 * and basic hierarchy are correct.
  	 *
  	 * With this assumption enabled, normal device trees produced by libfdt
  	 * and the compiler should be handled safely. Malicious device trees and
  	 * complete garbage may cause libfdt to behave badly or crash. Truncated
  	 * device trees (e.g. those only partially loaded) can also cause
  	 * problems.
  	 *
  	 * Note: Only checks that relate exclusively to the device tree itself
  	 * (not the parameters passed to libfdt) are disabled by this
  	 * assumption. This includes checking headers, tags and the like.
  	 */
  	ASSUME_VALID_DTB	= 1 << 0,
  
  	/*
  	 * This builds on ASSUME_VALID_DTB and further assumes that libfdt
  	 * functions are called with valid parameters, i.e. not trigger
  	 * FDT_ERR_BADOFFSET or offsets that are out of bounds. It disables any
  	 * extensive checking of parameters and the device tree, making various
  	 * assumptions about correctness.
  	 *
  	 * It doesn't make sense to enable this assumption unless
  	 * ASSUME_VALID_DTB is also enabled.
  	 */
  	ASSUME_VALID_INPUT	= 1 << 1,
  
  	/*
  	 * This disables checks for device-tree version and removes all code
  	 * which handles older versions.
  	 *
  	 * Only enable this if you know you have a device tree with the latest
  	 * version.
  	 */
  	ASSUME_LATEST		= 1 << 2,
  
  	/*
  	 * This assumes that it is OK for a failed addition to the device tree,
  	 * due to lack of space or some other problem, to skip any rollback
  	 * steps (such as dropping the property name from the string table).
  	 * This is safe to enable in most circumstances, even though it may
  	 * leave the tree in a sub-optimal state.
  	 */
  	ASSUME_NO_ROLLBACK	= 1 << 3,
  
  	/*
  	 * This assumes that the device tree components appear in a 'convenient'
  	 * order, i.e. the memory reservation block first, then the structure
  	 * block and finally the string block.
  	 *
  	 * This order is not specified by the device-tree specification,
  	 * but is expected by libfdt. The device-tree compiler always created
  	 * device trees with this order.
  	 *
  	 * This assumption disables a check in fdt_open_into() and removes the
  	 * ability to fix the problem there. This is safe if you know that the
  	 * device tree is correctly ordered. See fdt_blocks_misordered_().
  	 */
  	ASSUME_LIBFDT_ORDER	= 1 << 4,
  
  	/*
  	 * This assumes that libfdt itself does not have any internal bugs. It
  	 * drops certain checks that should never be needed unless libfdt has an
  	 * undiscovered bug.
  	 *
  	 * This can generally be considered safe to enable.
  	 */
  	ASSUME_LIBFDT_FLAWLESS	= 1 << 5,
  };
  
  /**
   * can_assume_() - check if a particular assumption is enabled
   *
   * @mask: Mask to check (ASSUME_...)
   * @return true if that assumption is enabled, else false
   */
  static inline bool can_assume_(int mask)
  {
  	return FDT_ASSUME_MASK & mask;
  }
  
  /** helper macros for checking assumptions */
  #define can_assume(_assume)	can_assume_(ASSUME_ ## _assume)
  
  #endif /* LIBFDT_INTERNAL_H */
  