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
tpm_read_log_of(struct tpm_chip * chip)20 int 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