include/linux/devcoredump.h

/*
 * 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 */