1 files changed, 108 insertions, 0 deletions
diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
new file mode 100644
index 0000000000..930fe43d5d
--- /dev/null
+++ b/drivers/char/tpm/eventlog/of.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2012 IBM Corporation
+ *
+ * Author: Ashley Lai <ashleydlai@gmail.com>
+ *         Nayna Jain <nayna@linux.vnet.ibm.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * Read the event log created by the firmware on PPC64
+ */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/tpm_eventlog.h>
+
+#include "../tpm.h"
+#include "common.h"
+
+static int tpm_read_log_memory_region(struct tpm_chip *chip)
+{
+	struct device_node *node;
+	struct resource res;
+	int rc;
+
+	node = of_parse_phandle(chip->dev.parent->of_node, "memory-region", 0);
+	if (!node)
+		return -ENODEV;
+
+	rc = of_address_to_resource(node, 0, &res);
+	of_node_put(node);
+	if (rc)
+		return rc;
+
+	chip->log.bios_event_log = devm_memremap(&chip->dev, res.start, resource_size(&res),
+						 MEMREMAP_WB);
+	if (IS_ERR(chip->log.bios_event_log))
+		return -ENOMEM;
+
+	chip->log.bios_event_log_end = chip->log.bios_event_log + resource_size(&res);
+
+	return chip->flags & TPM_CHIP_FLAG_TPM2 ? EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 :
+		EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
+}
+
+int tpm_read_log_of(struct tpm_chip *chip)
+{
+	struct device_node *np;
+	const u32 *sizep;
+	const u64 *basep;
+	struct tpm_bios_log *log;
+	u32 size;
+	u64 base;
+
+	log = &chip->log;
+	if (chip->dev.parent && chip->dev.parent->of_node)
+		np = chip->dev.parent->of_node;
+	else
+		return -ENODEV;
+
+	if (of_property_read_bool(np, "powered-while-suspended"))
+		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
+
+	sizep = of_get_property(np, "linux,sml-size", NULL);
+	basep = of_get_property(np, "linux,sml-base", NULL);
+	if (sizep == NULL && basep == NULL)
+		return tpm_read_log_memory_region(chip);
+	if (sizep == NULL || basep == NULL)
+		return -EIO;
+
+	/*
+	 * For both vtpm/tpm, firmware has log addr and log size in big
+	 * endian format. But in case of vtpm, there is a method called
+	 * sml-handover which is run during kernel init even before
+	 * device tree is setup. This sml-handover function takes care
+	 * of endianness and writes to sml-base and sml-size in little
+	 * endian format. For this reason, vtpm doesn't need conversion
+	 * but physical tpm needs the conversion.
+	 */
+	if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
+	    of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
+		size = be32_to_cpup((__force __be32 *)sizep);
+		base = be64_to_cpup((__force __be64 *)basep);
+	} else {
+		size = *sizep;
+		base = *basep;
+	}
+
+	if (size == 0) {
+		dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
+		return -EIO;
+	}
+
+	log->bios_event_log = devm_kmemdup(&chip->dev, __va(base), size, GFP_KERNEL);
+	if (!log->bios_event_log)
+		return -ENOMEM;
+
+	log->bios_event_log_end = log->bios_event_log + size;
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		return EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
+	return EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
+}