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