text: // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
  /******************************************************************************
   *
   * Module Name: dbhistry - debugger HISTORY command
   *
   * Copyright (C) 2000 - 2019, Intel Corp.
   *
   *****************************************************************************/
  
  #include <acpi/acpi.h>
  #include "accommon.h"
  #include "acdebug.h"
  
  #define _COMPONENT          ACPI_CA_DEBUGGER
  ACPI_MODULE_NAME("dbhistry")
  
  #define HI_NO_HISTORY       0
  #define HI_RECORD_HISTORY   1
  #define HISTORY_SIZE        40
  typedef struct history_info {
  	char *command;
  	u32 cmd_num;
  
  } HISTORY_INFO;
  
  static HISTORY_INFO acpi_gbl_history_buffer[HISTORY_SIZE];
  static u16 acpi_gbl_lo_history = 0;
  static u16 acpi_gbl_num_history = 0;
  static u16 acpi_gbl_next_history_index = 0;
  u32 acpi_gbl_next_cmd_num = 1;
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_db_add_to_history
   *
   * PARAMETERS:  command_line    - Command to add
   *
   * RETURN:      None
   *
   * DESCRIPTION: Add a command line to the history buffer.
   *
   ******************************************************************************/
  
  void acpi_db_add_to_history(char *command_line)
  {
  	u16 cmd_len;
  	u16 buffer_len;
  
  	/* Put command into the next available slot */
  
  	cmd_len = (u16)strlen(command_line);
  	if (!cmd_len) {
  		return;
  	}
  
  	if (acpi_gbl_history_buffer[acpi_gbl_next_history_index].command !=
  	    NULL) {
  		buffer_len =
  		    (u16)
  		    strlen(acpi_gbl_history_buffer[acpi_gbl_next_history_index].
  			   command);
  
  		if (cmd_len > buffer_len) {
  			acpi_os_free(acpi_gbl_history_buffer
  				     [acpi_gbl_next_history_index].command);
  			acpi_gbl_history_buffer[acpi_gbl_next_history_index].
  			    command = acpi_os_allocate(cmd_len + 1);
  		}
  	} else {
  		acpi_gbl_history_buffer[acpi_gbl_next_history_index].command =
  		    acpi_os_allocate(cmd_len + 1);
  	}
  
  	strcpy(acpi_gbl_history_buffer[acpi_gbl_next_history_index].command,
  	       command_line);
  
  	acpi_gbl_history_buffer[acpi_gbl_next_history_index].cmd_num =
  	    acpi_gbl_next_cmd_num;
  
  	/* Adjust indexes */
  
  	if ((acpi_gbl_num_history == HISTORY_SIZE) &&
  	    (acpi_gbl_next_history_index == acpi_gbl_lo_history)) {
  		acpi_gbl_lo_history++;
  		if (acpi_gbl_lo_history >= HISTORY_SIZE) {
  			acpi_gbl_lo_history = 0;
  		}
  	}
  
  	acpi_gbl_next_history_index++;
  	if (acpi_gbl_next_history_index >= HISTORY_SIZE) {
  		acpi_gbl_next_history_index = 0;
  	}
  
  	acpi_gbl_next_cmd_num++;
  	if (acpi_gbl_num_history < HISTORY_SIZE) {
  		acpi_gbl_num_history++;
  	}
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_db_display_history
   *
   * PARAMETERS:  None
   *
   * RETURN:      None
   *
   * DESCRIPTION: Display the contents of the history buffer
   *
   ******************************************************************************/
  
  void acpi_db_display_history(void)
  {
  	u32 i;
  	u16 history_index;
  
  	history_index = acpi_gbl_lo_history;
  
  	/* Dump entire history buffer */
  
  	for (i = 0; i < acpi_gbl_num_history; i++) {
  		if (acpi_gbl_history_buffer[history_index].command) {
  			acpi_os_printf("%3ld %s\n",
  				       acpi_gbl_history_buffer[history_index].
  				       cmd_num,
  				       acpi_gbl_history_buffer[history_index].
  				       command);
  		}
  
  		history_index++;
  		if (history_index >= HISTORY_SIZE) {
  			history_index = 0;
  		}
  	}
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_db_get_from_history
   *
   * PARAMETERS:  command_num_arg         - String containing the number of the
   *                                        command to be retrieved
   *
   * RETURN:      Pointer to the retrieved command. Null on error.
   *
   * DESCRIPTION: Get a command from the history buffer
   *
   ******************************************************************************/
  
  char *acpi_db_get_from_history(char *command_num_arg)
  {
  	u32 cmd_num;
  
  	if (command_num_arg == NULL) {
  		cmd_num = acpi_gbl_next_cmd_num - 1;
  	}
  
  	else {
  		cmd_num = strtoul(command_num_arg, NULL, 0);
  	}
  
  	return (acpi_db_get_history_by_index(cmd_num));
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_db_get_history_by_index
   *
   * PARAMETERS:  cmd_num             - Index of the desired history entry.
   *                                    Values are 0...(acpi_gbl_next_cmd_num - 1)
   *
   * RETURN:      Pointer to the retrieved command. Null on error.
   *
   * DESCRIPTION: Get a command from the history buffer
   *
   ******************************************************************************/
  
  char *acpi_db_get_history_by_index(u32 cmd_num)
  {
  	u32 i;
  	u16 history_index;
  
  	/* Search history buffer */
  
  	history_index = acpi_gbl_lo_history;
  	for (i = 0; i < acpi_gbl_num_history; i++) {
  		if (acpi_gbl_history_buffer[history_index].cmd_num == cmd_num) {
  
  			/* Found the command, return it */
  
  			return (acpi_gbl_history_buffer[history_index].command);
  		}
  
  		/* History buffer is circular */
  
  		history_index++;
  		if (history_index >= HISTORY_SIZE) {
  			history_index = 0;
  		}
  	}
  
  	acpi_os_printf("Invalid history number: %u\n", history_index);
  	return (NULL);
  }
  