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/io.h>
16#include <linux/ioport.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/of_reserved_mem.h>
20#include <linux/tpm_eventlog.h>
21
22#include "../tpm.h"
23#include "common.h"
24
25static int tpm_read_log_memory_region(struct tpm_chip *chip)
26{
27 struct device_node *node;
28 struct resource res;
29 int rc;
30
31 node = of_parse_phandle(np: chip->dev.parent->of_node, phandle_name: "memory-region", index: 0);
32 if (!node)
33 return -ENODEV;
34
35 rc = of_address_to_resource(dev: node, index: 0, r: &res);
36 of_node_put(node);
37 if (rc)
38 return rc;
39
40 chip->log.bios_event_log = devm_memremap(dev: &chip->dev, offset: res.start, size: resource_size(res: &res),
41 flags: MEMREMAP_WB);
42 if (IS_ERR(ptr: chip->log.bios_event_log))
43 return -ENOMEM;
44
45 chip->log.bios_event_log_end = chip->log.bios_event_log + resource_size(res: &res);
46
47 return chip->flags & TPM_CHIP_FLAG_TPM2 ? EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 :
48 EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
49}
50
51int tpm_read_log_of(struct tpm_chip *chip)
52{
53 struct device_node *np;
54 const u32 *sizep;
55 const u64 *basep;
56 struct tpm_bios_log *log;
57 u32 size;
58 u64 base;
59
60 log = &chip->log;
61 if (chip->dev.parent && chip->dev.parent->of_node)
62 np = chip->dev.parent->of_node;
63 else
64 return -ENODEV;
65
66 if (of_property_read_bool(np, propname: "powered-while-suspended"))
67 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
68
69 sizep = of_get_property(node: np, name: "linux,sml-size", NULL);
70 basep = of_get_property(node: np, name: "linux,sml-base", NULL);
71 if (sizep == NULL && basep == NULL)
72 return tpm_read_log_memory_region(chip);
73 if (sizep == NULL || basep == NULL)
74 return -EIO;
75
76 /*
77 * For both vtpm/tpm, firmware has log addr and log size in big
78 * endian format. But in case of vtpm, there is a method called
79 * sml-handover which is run during kernel init even before
80 * device tree is setup. This sml-handover function takes care
81 * of endianness and writes to sml-base and sml-size in little
82 * endian format. For this reason, vtpm doesn't need conversion
83 * but physical tpm needs the conversion.
84 */
85 if (of_property_match_string(np, propname: "compatible", string: "IBM,vtpm") < 0 &&
86 of_property_match_string(np, propname: "compatible", string: "IBM,vtpm20") < 0) {
87 size = be32_to_cpup(p: (__force __be32 *)sizep);
88 base = be64_to_cpup(p: (__force __be64 *)basep);
89 } else {
90 size = *sizep;
91 base = *basep;
92 }
93
94 if (size == 0) {
95 dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
96 return -EIO;
97 }
98
99 log->bios_event_log = devm_kmemdup(dev: &chip->dev, __va(base), len: size, GFP_KERNEL);
100 if (!log->bios_event_log)
101 return -ENOMEM;
102
103 log->bios_event_log_end = log->bios_event_log + size;
104
105 if (chip->flags & TPM_CHIP_FLAG_TPM2)
106 return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
107 return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
108}
109

source code of linux/drivers/char/tpm/eventlog/of.c