cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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of.c (2137B)

      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
     20int 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}