/*
   * Copyright (c) 2014 Google, Inc.
   *
   * SPDX-License-Identifier:     GPL-2.0+
   */
  
  #ifndef __IOTRACE_H
  #define __IOTRACE_H
  
  #include <linux/types.h>
  
  /*
   * This file is designed to be included in arch/<arch>/include/asm/io.h.
   * It redirects all IO access through a tracing/checksumming feature for
   * testing purposes.
   */
  
  #if defined(CONFIG_IO_TRACE) && !defined(IOTRACE_IMPL) && \
  	!defined(CONFIG_SPL_BUILD)
  
  #undef readl
  #define readl(addr)	iotrace_readl((const void *)(addr))
  
  #undef writel
  #define writel(val, addr)	iotrace_writel(val, (const void *)(addr))
  
  #undef readw
  #define readw(addr)	iotrace_readw((const void *)(addr))
  
  #undef writew
  #define writew(val, addr)	iotrace_writew(val, (const void *)(addr))
  
  #undef readb
  #define readb(addr)	iotrace_readb((const void *)(addr))
  
  #undef writeb
  #define writeb(val, addr)	iotrace_writeb(val, (const void *)(addr))
  
  #endif
  
  /* Tracing functions which mirror their io.h counterparts */
  u32 iotrace_readl(const void *ptr);
  void iotrace_writel(ulong value, const void *ptr);
  u16 iotrace_readw(const void *ptr);
  void iotrace_writew(ulong value, const void *ptr);
  u8 iotrace_readb(const void *ptr);
  void iotrace_writeb(ulong value, const void *ptr);
  
  /**
   * iotrace_reset_checksum() - Reset the iotrace checksum
   */
  void iotrace_reset_checksum(void);
  
  /**
   * iotrace_get_checksum() - Get the current checksum value
   *
   * @return currect checksum value
   */
  u32 iotrace_get_checksum(void);
  
  /**
   * iotrace_set_enabled() - Set whether iotracing is enabled or not
   *
   * This controls whether the checksum is updated and a trace record added
   * for each I/O access.
   *
   * @enable: true to enable iotracing, false to disable
   */
  void iotrace_set_enabled(int enable);
  
  /**
   * iotrace_get_enabled() - Get whether iotracing is enabled or not
   *
   * @return true if enabled, false if disabled
   */
  int iotrace_get_enabled(void);
  
  /**
   * iotrace_set_buffer() - Set position and size of iotrace buffer
   *
   * Defines where the iotrace buffer goes, and resets the output pointer to
   * the start of the buffer.
   *
   * The buffer can be 0 size in which case the checksum is updated but no
   * trace records are writen. If the buffer is exhausted, the offset will
   * continue to increase but not new data will be written.
   *
   * @start: Start address of buffer
   * @size: Size of buffer in bytes
   */
  void iotrace_set_buffer(ulong start, ulong size);
  
  /**
   * iotrace_get_buffer() - Get buffer information
   *
   * @start: Returns start address of buffer
   * @size: Returns size of buffer in bytes
   * @offset: Returns the byte offset where the next output trace record will
   * @count: Returns the number of trace records recorded
   * be written (or would be if the buffer was large enough)
   */
  void iotrace_get_buffer(ulong *start, ulong *size, ulong *offset, ulong *count);
  
  #endif /* __IOTRACE_H */