drivers/char/tpm/tpm_of.c

   1 /*
   2  * Copyright 2012 IBM Corporation
   3  *
   4  * Author: Ashley Lai <adlai@us.ibm.com>
   5  *
   6  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
   7  *
   8  * Read the event log created by the firmware on PPC64
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version
  13  * 2 of the License, or (at your option) any later version.
  14  *
  15  */
  16
  17 #include <linux/slab.h>
  18 #include <linux/of.h>
  19
  20 #include "tpm.h"
  21 #include "tpm_eventlog.h"
  22
  23 int read_log(struct tpm_bios_log *log)
  24 {
  25         struct device_node *np;
  26         const u32 *sizep;
  27         const __be64 *basep;
  28
  29         if (log->bios_event_log != NULL) {
  30                 pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
  31                 return -EFAULT;
  32         }
  33
  34         np = of_find_node_by_name(NULL, "ibm,vtpm");
  35         if (!np) {
  36                 pr_err("%s: ERROR - IBMVTPM not supported\n", __func__);
  37                 return -ENODEV;
  38         }
  39
  40         sizep = of_get_property(np, "linux,sml-size", NULL);
  41         if (sizep == NULL) {
  42                 pr_err("%s: ERROR - SML size not found\n", __func__);
  43                 goto cleanup_eio;
  44         }
  45         if (*sizep == 0) {
  46                 pr_err("%s: ERROR - event log area empty\n", __func__);
  47                 goto cleanup_eio;
  48         }
  49
  50         basep = of_get_property(np, "linux,sml-base", NULL);
  51         if (basep == NULL) {
  52                 pr_err(KERN_ERR "%s: ERROR - SML not found\n", __func__);
  53                 goto cleanup_eio;
  54         }
  55
  56         of_node_put(np);
  57         log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
  58         if (!log->bios_event_log) {
  59                 pr_err("%s: ERROR - Not enough memory for BIOS measurements\n",
  60                        __func__);
  61                 return -ENOMEM;
  62         }
  63
  64         log->bios_event_log_end = log->bios_event_log + *sizep;
  65
  66         memcpy(log->bios_event_log, __va(be64_to_cpup(basep)), *sizep);
  67
  68         return 0;
  69
  70 cleanup_eio:
  71         of_node_put(np);
  72         return -EIO;
  73 }