1 /*
2  * This file is provided under the GPLv2 license.
3  *
4  * GPL LICENSE SUMMARY
5  *
6  * Copyright(c) 2015 Intel Deutschland GmbH
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of version 2 of the GNU General Public License as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * The full GNU General Public License is included in this distribution
18  * in the file called COPYING.
19  */
20 #ifndef __DEVCOREDUMP_H
21 #define __DEVCOREDUMP_H
22 
23 #include <linux/device.h>
24 #include <linux/module.h>
25 #include <linux/vmalloc.h>
26 
27 #include <linux/scatterlist.h>
28 #include <linux/slab.h>
29 
30 /*
31  * _devcd_free_sgtable - free all the memory of the given scatterlist table
32  * (i.e. both pages and scatterlist instances)
33  * NOTE: if two tables allocated and chained using the sg_chain function then
34  * this function should be called only once on the first table
35  * @table: pointer to sg_table to free
36  */
_devcd_free_sgtable(struct scatterlist * table)37 static inline void _devcd_free_sgtable(struct scatterlist *table)
38 {
39 	int i;
40 	struct page *page;
41 	struct scatterlist *iter;
42 	struct scatterlist *delete_iter;
43 
44 	/* free pages */
45 	iter = table;
46 	for_each_sg(table, iter, sg_nents(table), i) {
47 		page = sg_page(iter);
48 		if (page)
49 			__free_page(page);
50 	}
51 
52 	/* then free all chained tables */
53 	iter = table;
54 	delete_iter = table;	/* always points on a head of a table */
55 	while (!sg_is_last(iter)) {
56 		iter++;
57 		if (sg_is_chain(iter)) {
58 			iter = sg_chain_ptr(iter);
59 			kfree(delete_iter);
60 			delete_iter = iter;
61 		}
62 	}
63 
64 	/* free the last table */
65 	kfree(delete_iter);
66 }
67 
68 
69 #ifdef CONFIG_DEV_COREDUMP
70 void dev_coredumpv(struct device *dev, void *data, size_t datalen,
71 		   gfp_t gfp);
72 
73 void dev_coredumpm(struct device *dev, struct module *owner,
74 		   void *data, size_t datalen, gfp_t gfp,
75 		   ssize_t (*read)(char *buffer, loff_t offset, size_t count,
76 				   void *data, size_t datalen),
77 		   void (*free)(void *data));
78 
79 void dev_coredumpsg(struct device *dev, struct scatterlist *table,
80 		    size_t datalen, gfp_t gfp);
81 #else
dev_coredumpv(struct device * dev,void * data,size_t datalen,gfp_t gfp)82 static inline void dev_coredumpv(struct device *dev, void *data,
83 				 size_t datalen, gfp_t gfp)
84 {
85 	vfree(data);
86 }
87 
88 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))89 dev_coredumpm(struct device *dev, struct module *owner,
90 	      void *data, size_t datalen, gfp_t gfp,
91 	      ssize_t (*read)(char *buffer, loff_t offset, size_t count,
92 			      void *data, size_t datalen),
93 	      void (*free)(void *data))
94 {
95 	free(data);
96 }
97 
dev_coredumpsg(struct device * dev,struct scatterlist * table,size_t datalen,gfp_t gfp)98 static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table,
99 				  size_t datalen, gfp_t gfp)
100 {
101 	_devcd_free_sgtable(table);
102 }
103 #endif /* CONFIG_DEV_COREDUMP */
104 
105 #endif /* __DEVCOREDUMP_H */
106