/*
   * This file is provided under the GPLv2 license.
   *
   * GPL LICENSE SUMMARY
   *
   * Copyright(c) 2015 Intel Deutschland GmbH
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of version 2 of the GNU General Public License as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * The full GNU General Public License is included in this distribution
   * in the file called COPYING.
   */

  #ifndef __DEVCOREDUMP_H
  #define __DEVCOREDUMP_H
  
  #include <linux/device.h>
  #include <linux/module.h>
  #include <linux/vmalloc.h>

  #include <linux/scatterlist.h>
  #include <linux/slab.h>
  
  /*
   * _devcd_free_sgtable - free all the memory of the given scatterlist table
   * (i.e. both pages and scatterlist instances)
   * NOTE: if two tables allocated and chained using the sg_chain function then
   * this function should be called only once on the first table
   * @table: pointer to sg_table to free
   */
  static inline void _devcd_free_sgtable(struct scatterlist *table)
  {
  	int i;
  	struct page *page;
  	struct scatterlist *iter;
  	struct scatterlist *delete_iter;
  
  	/* free pages */
  	iter = table;
  	for_each_sg(table, iter, sg_nents(table), i) {
  		page = sg_page(iter);
  		if (page)
  			__free_page(page);
  	}
  
  	/* then free all chained tables */
  	iter = table;
  	delete_iter = table;	/* always points on a head of a table */
  	while (!sg_is_last(iter)) {
  		iter++;
  		if (sg_is_chain(iter)) {
  			iter = sg_chain_ptr(iter);
  			kfree(delete_iter);
  			delete_iter = iter;
  		}
  	}
  
  	/* free the last table */
  	kfree(delete_iter);
  }

  #ifdef CONFIG_DEV_COREDUMP

  void dev_coredumpv(struct device *dev, void *data, size_t datalen,

  		   gfp_t gfp);
  
  void dev_coredumpm(struct device *dev, struct module *owner,

  		   void *data, size_t datalen, gfp_t gfp,

  		   ssize_t (*read)(char *buffer, loff_t offset, size_t count,

  				   void *data, size_t datalen),
  		   void (*free)(void *data));
  
  void dev_coredumpsg(struct device *dev, struct scatterlist *table,
  		    size_t datalen, gfp_t gfp);

  #else

  static inline void dev_coredumpv(struct device *dev, void *data,

  				 size_t datalen, gfp_t gfp)
  {
  	vfree(data);
  }
  
  static inline void
  dev_coredumpm(struct device *dev, struct module *owner,

  	      void *data, size_t datalen, gfp_t gfp,

  	      ssize_t (*read)(char *buffer, loff_t offset, size_t count,

  			      void *data, size_t datalen),
  	      void (*free)(void *data))

  {
  	free(data);
  }

  
  static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table,
  				  size_t datalen, gfp_t gfp)
  {
  	_devcd_free_sgtable(table);
  }

  #endif /* CONFIG_DEV_COREDUMP */
  
  #endif /* __DEVCOREDUMP_H */