1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 2012 IBM Corporation
4 *
5 * Author: Ashley Lai <ashleydlai@gmail.com>
6 *         Nayna Jain <nayna@linux.vnet.ibm.com>
7 *
8 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9 *
10 * Read the event log created by the firmware on PPC64
11 */
12
13#include <linux/slab.h>
14#include <linux/of.h>
15#include <linux/tpm_eventlog.h>
16
17#include "../tpm.h"
18#include "common.h"
19
20int tpm_read_log_of(struct tpm_chip *chip)
21{
22	struct device_node *np;
23	const u32 *sizep;
24	const u64 *basep;
25	struct tpm_bios_log *log;
26	u32 size;
27	u64 base;
28
29	log = &chip->log;
30	if (chip->dev.parent && chip->dev.parent->of_node)
31		np = chip->dev.parent->of_node;
32	else
33		return -ENODEV;
34
35	if (of_property_read_bool(np, "powered-while-suspended"))
36		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
37
38	sizep = of_get_property(np, "linux,sml-size", NULL);
39	basep = of_get_property(np, "linux,sml-base", NULL);
40	if (sizep == NULL && basep == NULL)
41		return -ENODEV;
42	if (sizep == NULL || basep == NULL)
43		return -EIO;
44
45	/*
46	 * For both vtpm/tpm, firmware has log addr and log size in big
47	 * endian format. But in case of vtpm, there is a method called
48	 * sml-handover which is run during kernel init even before
49	 * device tree is setup. This sml-handover function takes care
50	 * of endianness and writes to sml-base and sml-size in little
51	 * endian format. For this reason, vtpm doesn't need conversion
52	 * but physical tpm needs the conversion.
53	 */
54	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
55	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
56		size = be32_to_cpup((__force __be32 *)sizep);
57		base = be64_to_cpup((__force __be64 *)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 = kmemdup(__va(base), 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	if (chip->flags & TPM_CHIP_FLAG_TPM2)
75		return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
76	return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
77}
78