1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_eventlog_efi.c b/drivers/char/tpm/tpm_eventlog_efi.c
new file mode 100644
index 000000000000..e3f9ffd341d2
--- /dev/null
+++ b/drivers/char/tpm/tpm_eventlog_efi.c
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2017 Google
+ *
+ * Authors:
+ *      Thiebaud Weksteen <tweek@google.com>
+ *
+ * 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/efi.h>
+#include <linux/tpm_eventlog.h>
+
+#include "tpm.h"
+
+/* read binary bios log from EFI configuration table */
+int tpm_read_log_efi(struct tpm_chip *chip)
+{
+
+	struct linux_efi_tpm_eventlog *log_tbl;
+	struct tpm_bios_log *log;
+	u32 log_size;
+	u8 tpm_log_version;
+
+	if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
+		return -ENODEV;
+
+	if (efi.tpm_log == EFI_INVALID_TABLE_ADDR)
+		return -ENODEV;
+
+	log = &chip->log;
+
+	log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl), MEMREMAP_WB);
+	if (!log_tbl) {
+		pr_err("Could not map UEFI TPM log table !\n");
+		return -ENOMEM;
+	}
+
+	log_size = log_tbl->size;
+	memunmap(log_tbl);
+
+	log_tbl = memremap(efi.tpm_log, sizeof(*log_tbl) + log_size,
+			   MEMREMAP_WB);
+	if (!log_tbl) {
+		pr_err("Could not map UEFI TPM log table payload!\n");
+		return -ENOMEM;
+	}
+
+	/* malloc EventLog space */
+	log->bios_event_log = kmalloc(log_size, GFP_KERNEL);
+	if (!log->bios_event_log)
+		goto err_memunmap;
+	memcpy(log->bios_event_log, log_tbl->log, log_size);
+	log->bios_event_log_end = log->bios_event_log + log_size;
+
+	tpm_log_version = log_tbl->version;
+	memunmap(log_tbl);
+	return tpm_log_version;
+
+err_memunmap:
+	memunmap(log_tbl);
+	return -ENOMEM;
+}