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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright(c) 2015 Intel Deutschland GmbH
4 */
5#ifndef __DEVCOREDUMP_H
6#define __DEVCOREDUMP_H
7
8#include <linux/device.h>
9#include <linux/module.h>
10#include <linux/vmalloc.h>
11
12#include <linux/scatterlist.h>
13#include <linux/slab.h>
14
15/* if data isn't read by userspace after 5 minutes then delete it */
16#define DEVCD_TIMEOUT (HZ * 60 * 5)
17
18/*
19 * _devcd_free_sgtable - free all the memory of the given scatterlist table
20 * (i.e. both pages and scatterlist instances)
21 * NOTE: if two tables allocated and chained using the sg_chain function then
22 * this function should be called only once on the first table
23 * @table: pointer to sg_table to free
24 */
25static inline void _devcd_free_sgtable(struct scatterlist *table)
26{
27 int i;
28 struct page *page;
29 struct scatterlist *iter;
30 struct scatterlist *delete_iter;
31
32 /* free pages */
33 iter = table;
34 for_each_sg(table, iter, sg_nents(table), i) {
35 page = sg_page(iter);
36 if (page)
37 __free_page(page);
38 }
39
40 /* then free all chained tables */
41 iter = table;
42 delete_iter = table; /* always points on a head of a table */
43 while (!sg_is_last(iter)) {
44 iter++;
45 if (sg_is_chain(iter)) {
46 iter = sg_chain_ptr(iter);
47 kfree(delete_iter);
48 delete_iter = iter;
49 }
50 }
51
52 /* free the last table */
53 kfree(delete_iter);
54}
55
56#ifdef CONFIG_DEV_COREDUMP
57void dev_coredumpv(struct device *dev, void *data, size_t datalen,
58 gfp_t gfp);
59
60void dev_coredumpm_timeout(struct device *dev, struct module *owner,
61 void *data, size_t datalen, gfp_t gfp,
62 ssize_t (*read)(char *buffer, loff_t offset,
63 size_t count, void *data,
64 size_t datalen),
65 void (*free)(void *data),
66 unsigned long timeout);
67
68void dev_coredumpsg(struct device *dev, struct scatterlist *table,
69 size_t datalen, gfp_t gfp);
70
71void dev_coredump_put(struct device *dev);
72#else
73static inline void dev_coredumpv(struct device *dev, void *data,
74 size_t datalen, gfp_t gfp)
75{
76 vfree(data);
77}
78
79static inline void
80dev_coredumpm_timeout(struct device *dev, struct module *owner,
81 void *data, size_t datalen, gfp_t gfp,
82 ssize_t (*read)(char *buffer, loff_t offset,
83 size_t count, void *data,
84 size_t datalen),
85 void (*free)(void *data),
86 unsigned long timeout)
87{
88 free(data);
89}
90
91static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table,
92 size_t datalen, gfp_t gfp)
93{
94 _devcd_free_sgtable(table);
95}
96static inline void dev_coredump_put(struct device *dev)
97{
98}
99#endif /* CONFIG_DEV_COREDUMP */
100
101/**
102 * dev_coredumpm - create device coredump with read/free methods
103 * @dev: the struct device for the crashed device
104 * @owner: the module that contains the read/free functions, use %THIS_MODULE
105 * @data: data cookie for the @read/@free functions
106 * @datalen: length of the data
107 * @gfp: allocation flags
108 * @read: function to read from the given buffer
109 * @free: function to free the given buffer
110 *
111 * Creates a new device coredump for the given device. If a previous one hasn't
112 * been read yet, the new coredump is discarded. The data lifetime is determined
113 * by the device coredump framework and when it is no longer needed the @free
114 * function will be called to free the data.
115 */
116static inline void dev_coredumpm(struct device *dev, struct module *owner,
117 void *data, size_t datalen, gfp_t gfp,
118 ssize_t (*read)(char *buffer, loff_t offset, size_t count,
119 void *data, size_t datalen),
120 void (*free)(void *data))
121{
122 dev_coredumpm_timeout(dev, owner, data, datalen, gfp, read, free,
123 DEVCD_TIMEOUT);
124}
125
126#endif /* __DEVCOREDUMP_H */