tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright 2012 IBM Corporation
3 *
4 * Author: Ashley Lai <ashleydlai@gmail.com>
5 * Nayna Jain <nayna@linux.vnet.ibm.com>
6 *
7 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
8 *
9 * Read the event log created by the firmware on PPC64
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 *
16 */
17
18#include <linux/slab.h>
19#include <linux/of.h>
20
21#include "tpm.h"
22#include "tpm_eventlog.h"
23
24int tpm_read_log_of(struct tpm_chip *chip)
25{
26 struct device_node *np;
27 const u32 *sizep;
28 const u64 *basep;
29 struct tpm_bios_log *log;
30 u32 size;
31 u64 base;
32
33 log = &chip->log;
34 if (chip->dev.parent && chip->dev.parent->of_node)
35 np = chip->dev.parent->of_node;
36 else
37 return -ENODEV;
38
39 sizep = of_get_property(np, "linux,sml-size", NULL);
40 basep = of_get_property(np, "linux,sml-base", NULL);
41 if (sizep == NULL && basep == NULL)
42 return -ENODEV;
43 if (sizep == NULL || basep == NULL)
44 return -EIO;
45
46 /*
47 * For both vtpm/tpm, firmware has log addr and log size in big
48 * endian format. But in case of vtpm, there is a method called
49 * sml-handover which is run during kernel init even before
50 * device tree is setup. This sml-handover function takes care
51 * of endianness and writes to sml-base and sml-size in little
52 * endian format. For this reason, vtpm doesn't need conversion
53 * but physical tpm needs the conversion.
54 */
55 if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0) {
56 size = be32_to_cpup(sizep);
57 base = be64_to_cpup(basep);
58 } else {
59 size = *sizep;
60 base = *basep;
61 }
62
63 if (size == 0) {
64 dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
65 return -EIO;
66 }
67
68 log->bios_event_log = kmalloc(size, GFP_KERNEL);
69 if (!log->bios_event_log)
70 return -ENOMEM;
71
72 log->bios_event_log_end = log->bios_event_log + size;
73
74 memcpy(log->bios_event_log, __va(base), size);
75
76 return 0;
77}