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/device.h>
14 #include <linux/slab.h>
15 #include <linux/of.h>
16 #include <linux/tpm_eventlog.h>
17
18 #include "../tpm.h"
19 #include "common.h"
20
tpm_read_log_of(struct tpm_chip * chip)21 int tpm_read_log_of(struct tpm_chip *chip)
22 {
23 struct device_node *np;
24 const u32 *sizep;
25 const u64 *basep;
26 struct tpm_bios_log *log;
27 u32 size;
28 u64 base;
29
30 log = &chip->log;
31 if (chip->dev.parent && chip->dev.parent->of_node)
32 np = chip->dev.parent->of_node;
33 else
34 return -ENODEV;
35
36 if (of_property_read_bool(np, "powered-while-suspended"))
37 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
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 of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
57 size = be32_to_cpup((__force __be32 *)sizep);
58 base = be64_to_cpup((__force __be64 *)basep);
59 } else {
60 size = *sizep;
61 base = *basep;
62 }
63
64 if (size == 0) {
65 dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
66 return -EIO;
67 }
68
69 log->bios_event_log = devm_kmemdup(&chip->dev, __va(base), size, GFP_KERNEL);
70 if (!log->bios_event_log)
71 return -ENOMEM;
72
73 log->bios_event_log_end = log->bios_event_log + size;
74
75 if (chip->flags & TPM_CHIP_FLAG_TPM2)
76 return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
77 return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
78 }
79