drivers/char/tpm: Add securityfs support for event log

This patch retrieves the event log data from the device tree
during file open. The event log data will then displayed through
securityfs.

Signed-off-by: Ashley Lai <adlai@us.ibm.com>
Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>

1 files changed, 73 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm_of.c b/drivers/char/tpm/tpm_of.c
new file mode 100644
index 000000000000..98ba2bd1a355
--- /dev/null
+++ b/drivers/char/tpm/tpm_of.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012 IBM Corporation
+ *
+ * Author: Ashley Lai <adlai@us.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Read the event log created by the firmware on PPC64
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "tpm.h"
+#include "tpm_eventlog.h"
+
+int read_log(struct tpm_bios_log *log)
+{
+        struct device_node *np;
+        const u32 *sizep;
+        const __be64 *basep;
+
+        if (log->bios_event_log != NULL) {
+                pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
+                return -EFAULT;
+        }
+
+        np = of_find_node_by_name(NULL, "ibm,vtpm");
+        if (!np) {
+                pr_err("%s: ERROR - IBMVTPM not supported\n", __func__);
+                return -ENODEV;
+        }
+
+        sizep = of_get_property(np, "linux,sml-size", NULL);
+        if (sizep == NULL) {
+                pr_err("%s: ERROR - SML size not found\n", __func__);
+                goto cleanup_eio;
+        }
+        if (*sizep == 0) {
+                pr_err("%s: ERROR - event log area empty\n", __func__);
+                goto cleanup_eio;
+        }
+
+        basep = of_get_property(np, "linux,sml-base", NULL);
+        if (basep == NULL) {
+                pr_err(KERN_ERR "%s: ERROR - SML not found\n", __func__);
+                goto cleanup_eio;
+        }
+
+        of_node_put(np);
+        log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
+        if (!log->bios_event_log) {
+                pr_err("%s: ERROR - Not enough memory for BIOS measurements\n",
+                       __func__);
+                return -ENOMEM;
+        }
+
+        log->bios_event_log_end = log->bios_event_log + *sizep;
+
+        memcpy(log->bios_event_log, __va(be64_to_cpup(basep)), *sizep);
+
+        return 0;
+
+cleanup_eio:
+        of_node_put(np);
+        return -EIO;
+}