root/drivers/char/tpm/eventlog/of.c

DEFINITIONS

1. tpm_read_log_of

   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 
  20 int 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                 size = be32_to_cpup((__force __be32 *)sizep);
  56                 base = be64_to_cpup((__force __be64 *)basep);
  57         } else {
  58                 size = *sizep;
  59                 base = *basep;
  60         }
  61 
  62         if (size == 0) {
  63                 dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
  64                 return -EIO;
  65         }
  66 
  67         log->bios_event_log = kmemdup(__va(base), size, GFP_KERNEL);
  68         if (!log->bios_event_log)
  69                 return -ENOMEM;
  70 
  71         log->bios_event_log_end = log->bios_event_log + size;
  72 
  73         if (chip->flags & TPM_CHIP_FLAG_TPM2)
  74                 return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
  75         return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
  76 }