From 1e2714bb83fc783d58701967391bea242c65eaff Mon Sep 17 00:00:00 2001
From: Eddie James <eajames@linux.ibm.com>
Date: Thu, 26 Jan 2023 15:08:10 -0600
Subject: [PATCH] tpm: Add reserved memory event log
Some platforms may desire to pass the event log up to Linux in the
form of a reserved memory region. In particular, this is desirable
for embedded systems or baseboard management controllers (BMCs)
booting with U-Boot. IBM OpenBMC BMCs will be the first user.
Add support for the reserved memory in the TPM core to find the
region and map it.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
[jarkko: removed spurious dev_info()'s from tpm_read_log_memory_region()]
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
[yang: return -ENOMEM when devm_memremap() fails]
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
drivers/char/tpm/eventlog/of.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
index 741ab2204b11..930fe43d5daf 100644
--- a/drivers/char/tpm/eventlog/of.c
+++ b/drivers/char/tpm/eventlog/of.c
@@ -12,12 +12,42 @@
#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;
@@ -39,7 +69,7 @@ int tpm_read_log_of(struct tpm_chip *chip)
sizep = of_get_property(np, "linux,sml-size", NULL);
basep = of_get_property(np, "linux,sml-base", NULL);
if (sizep == NULL && basep == NULL)
- return -ENODEV;
+ return tpm_read_log_memory_region(chip);
if (sizep == NULL || basep == NULL)
return -EIO;