of.c

  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 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
 45int 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}