[PATCH v9 03/15] FWU: Add FWU metadata access driver for GPT partitioned block devices

Sughosh Ganu sughosh.ganu at linaro.org
Fri Aug 26 11:57:04 CEST 2022


In the FWU Multi Bank Update feature, the information about the
updatable images is stored as part of the metadata, on a separate
partition. Add a driver for reading from and writing to the metadata
when the updatable images and the metadata are stored on a block
device which is formated with GPT based partition scheme.

Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---
Changes since V8:
* Rename fwu_mdata_gpt_blk.c as gpt_blk.c as suggested by Simon
* Use natural integer types instead of specific width integers as
  suggested by Simon
* Fix return codes as suggested by Simon
* Code cleanup of some superfluous error checks, like for
  dev_get_uclass_plat() function
* Use blk_get_from_parent() for getting the parent of the block device
  containing the FWU metadata
* Add comments to the API functions

 drivers/fwu-mdata/Kconfig   |  16 ++
 drivers/fwu-mdata/Makefile  |   8 +
 drivers/fwu-mdata/gpt_blk.c | 378 ++++++++++++++++++++++++++++++++++++
 include/fwu.h               |   4 +
 4 files changed, 406 insertions(+)
 create mode 100644 drivers/fwu-mdata/Kconfig
 create mode 100644 drivers/fwu-mdata/Makefile
 create mode 100644 drivers/fwu-mdata/gpt_blk.c

diff --git a/drivers/fwu-mdata/Kconfig b/drivers/fwu-mdata/Kconfig
new file mode 100644
index 0000000000..7322da48b1
--- /dev/null
+++ b/drivers/fwu-mdata/Kconfig
@@ -0,0 +1,16 @@
+config FWU_MDATA
+	bool "Driver support for accessing FWU Metadata"
+	depends on DM
+	help
+	  Enable support for accessing FWU Metadata partitions. The
+	  FWU Metadata partitions reside on the same storage device
+	  which contains the other FWU updatable firmware images.
+
+config FWU_MDATA_GPT_BLK
+	bool "FWU Metadata access for GPT partitioned Block devices"
+	select PARTITION_TYPE_GUID
+	select PARTITION_UUIDS
+	depends on DM && HAVE_BLOCK_DEVICE && EFI_PARTITION
+	help
+	  Enable support for accessing FWU Metadata on GPT partitioned
+	  block devices.
diff --git a/drivers/fwu-mdata/Makefile b/drivers/fwu-mdata/Makefile
new file mode 100644
index 0000000000..3fee64c10c
--- /dev/null
+++ b/drivers/fwu-mdata/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (c) 2022, Linaro Limited
+#
+
+
+obj-$(CONFIG_FWU_MDATA) += fwu-mdata-uclass.o
+obj-$(CONFIG_FWU_MDATA_GPT_BLK) += gpt_blk.o
diff --git a/drivers/fwu-mdata/gpt_blk.c b/drivers/fwu-mdata/gpt_blk.c
new file mode 100644
index 0000000000..4f0558825b
--- /dev/null
+++ b/drivers/fwu-mdata/gpt_blk.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022, Linaro Limited
+ */
+
+#define LOG_CATEGORY UCLASS_FWU_MDATA
+
+#include <blk.h>
+#include <dm.h>
+#include <efi_loader.h>
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <log.h>
+#include <memalign.h>
+#include <part.h>
+#include <part_efi.h>
+
+#include <dm/device-internal.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+
+#define PRIMARY_PART		BIT(0)
+#define SECONDARY_PART		BIT(1)
+#define BOTH_PARTS		(PRIMARY_PART | SECONDARY_PART)
+
+#define MDATA_READ		BIT(0)
+#define MDATA_WRITE		BIT(1)
+
+static int gpt_get_mdata_partitions(struct blk_desc *desc,
+				    uint *primary_mpart,
+				    uint *secondary_mpart)
+{
+	int i, ret;
+	u32 mdata_parts;
+	efi_guid_t part_type_guid;
+	struct disk_partition info;
+	const efi_guid_t fwu_mdata_guid = FWU_MDATA_GUID;
+
+	mdata_parts = 0;
+	for (i = 1; i < MAX_SEARCH_PARTITIONS; i++) {
+		if (part_get_info(desc, i, &info))
+			continue;
+		uuid_str_to_bin(info.type_guid, part_type_guid.b,
+				UUID_STR_FORMAT_GUID);
+
+		if (!guidcmp(&fwu_mdata_guid, &part_type_guid)) {
+			++mdata_parts;
+			if (!*primary_mpart)
+				*primary_mpart = i;
+			else
+				*secondary_mpart = i;
+		}
+	}
+
+	if (mdata_parts != 2) {
+		log_debug("Expect two copies of the FWU metadata instead of %d\n",
+			  mdata_parts);
+		ret = -EINVAL;
+	} else {
+		ret = 0;
+	}
+
+	return ret;
+}
+
+static int gpt_get_mdata_disk_part(struct blk_desc *desc,
+				   struct disk_partition *info,
+				   u32 part_num)
+{
+	int ret;
+	char *mdata_guid_str = "8a7a84a0-8387-40f6-ab41-a8b9a5a60d23";
+
+	ret = part_get_info(desc, part_num, info);
+	if (ret < 0) {
+		log_debug("Unable to get the partition info for the FWU metadata part %d",
+			  part_num);
+		return -ENOENT;
+	}
+
+	/* Check that it is indeed the FWU metadata partition */
+	if (!strncmp(info->type_guid, mdata_guid_str, UUID_STR_LEN)) {
+		/* Found the FWU metadata partition */
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+static int gpt_read_write_mdata(struct blk_desc *desc,
+				struct fwu_mdata *mdata,
+				u8 access, u32 part_num)
+{
+	int ret;
+	u32 len, blk_start, blkcnt;
+	struct disk_partition info;
+
+	ALLOC_CACHE_ALIGN_BUFFER_PAD(struct fwu_mdata, mdata_aligned, 1,
+				     desc->blksz);
+
+	ret = gpt_get_mdata_disk_part(desc, &info, part_num);
+	if (ret < 0) {
+		printf("Unable to get the FWU metadata partition\n");
+		return -ENOENT;
+	}
+
+	len = sizeof(*mdata);
+	blkcnt = BLOCK_CNT(len, desc);
+	if (blkcnt > info.size) {
+		log_debug("Block count exceeds FWU metadata partition size\n");
+		return -ERANGE;
+	}
+
+	blk_start = info.start;
+	if (access == MDATA_READ) {
+		if (blk_dread(desc, blk_start, blkcnt, mdata_aligned) != blkcnt) {
+			log_debug("Error reading FWU metadata from the device\n");
+			return -EIO;
+		}
+		memcpy(mdata, mdata_aligned, sizeof(struct fwu_mdata));
+	} else {
+		if (blk_dwrite(desc, blk_start, blkcnt, mdata) != blkcnt) {
+			log_debug("Error writing FWU metadata to the device\n");
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int gpt_read_mdata(struct blk_desc *desc,
+			  struct fwu_mdata *mdata, u32 part_num)
+{
+	return gpt_read_write_mdata(desc, mdata, MDATA_READ, part_num);
+}
+
+static int gpt_write_mdata_partition(struct blk_desc *desc,
+					struct fwu_mdata *mdata,
+					u32 part_num)
+{
+	return gpt_read_write_mdata(desc, mdata, MDATA_WRITE, part_num);
+}
+
+static int fwu_gpt_update_mdata(struct udevice *dev, struct fwu_mdata *mdata)
+{
+	int ret;
+	struct blk_desc *desc;
+	uint primary_mpart = 0, secondary_mpart = 0;
+	struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+	desc = dev_get_uclass_plat(priv->blk_dev);
+
+	ret = gpt_get_mdata_partitions(desc, &primary_mpart,
+				       &secondary_mpart);
+	if (ret < 0) {
+		log_debug("Error getting the FWU metadata partitions\n");
+		return -ENOENT;
+	}
+
+	/* First write the primary partition */
+	ret = gpt_write_mdata_partition(desc, mdata, primary_mpart);
+	if (ret < 0) {
+		log_debug("Updating primary FWU metadata partition failed\n");
+		return ret;
+	}
+
+	/* And now the replica */
+	ret = gpt_write_mdata_partition(desc, mdata, secondary_mpart);
+	if (ret < 0) {
+		log_debug("Updating secondary FWU metadata partition failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int gpt_get_mdata(struct blk_desc *desc, struct fwu_mdata *mdata)
+{
+	int ret;
+	uint primary_mpart = 0, secondary_mpart = 0;
+
+	ret = gpt_get_mdata_partitions(desc, &primary_mpart,
+				       &secondary_mpart);
+
+	if (ret < 0) {
+		log_debug("Error getting the FWU metadata partitions\n");
+		return -ENOENT;
+	}
+
+	ret = gpt_read_mdata(desc, mdata, primary_mpart);
+	if (ret < 0) {
+		log_debug("Failed to read the FWU metadata from the device\n");
+		return -EIO;
+	}
+
+	ret = fwu_verify_mdata(mdata, 1);
+	if (!ret)
+		return 0;
+
+	/*
+	 * Verification of the primary FWU metadata copy failed.
+	 * Try to read the replica.
+	 */
+	memset(mdata, '\0', sizeof(struct fwu_mdata));
+	ret = gpt_read_mdata(desc, mdata, secondary_mpart);
+	if (ret < 0) {
+		log_debug("Failed to read the FWU metadata from the device\n");
+		return -EIO;
+	}
+
+	ret = fwu_verify_mdata(mdata, 0);
+	if (!ret)
+		return 0;
+
+	/* Both the FWU metadata copies are corrupted. */
+	return -EIO;
+}
+
+static int gpt_check_mdata_validity(struct udevice *dev)
+{
+	int ret;
+	struct blk_desc *desc;
+	struct fwu_mdata pri_mdata;
+	struct fwu_mdata secondary_mdata;
+	uint primary_mpart = 0, secondary_mpart = 0;
+	uint valid_partitions, invalid_partitions;
+	struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+	desc = dev_get_uclass_plat(priv->blk_dev);
+
+	/*
+	 * Two FWU metadata partitions are expected.
+	 * If we don't have two, user needs to create
+	 * them first
+	 */
+	valid_partitions = 0;
+	ret = gpt_get_mdata_partitions(desc, &primary_mpart,
+				       &secondary_mpart);
+
+	if (ret < 0) {
+		log_debug("Error getting the FWU metadata partitions\n");
+		return -ENOENT;
+	}
+
+	ret = gpt_read_mdata(desc, &pri_mdata, primary_mpart);
+	if (ret < 0) {
+		log_debug("Failed to read the FWU metadata from the device\n");
+		goto secondary_read;
+	}
+
+	ret = fwu_verify_mdata(&pri_mdata, 1);
+	if (!ret)
+		valid_partitions |= PRIMARY_PART;
+
+secondary_read:
+	/* Now check the secondary partition */
+	ret = gpt_read_mdata(desc, &secondary_mdata, secondary_mpart);
+	if (ret < 0) {
+		log_debug("Failed to read the FWU metadata from the device\n");
+		goto mdata_restore;
+	}
+
+	ret = fwu_verify_mdata(&secondary_mdata, 0);
+	if (!ret)
+		valid_partitions |= SECONDARY_PART;
+
+mdata_restore:
+	if (valid_partitions == (PRIMARY_PART | SECONDARY_PART)) {
+		ret = -1;
+		/*
+		 * Before returning, check that both the
+		 * FWU metadata copies are the same. If not,
+		 * the FWU metadata copies need to be
+		 * re-populated.
+		 */
+		if (!memcmp(&pri_mdata, &secondary_mdata,
+			    sizeof(struct fwu_mdata))) {
+			ret = 0;
+		} else {
+			log_debug("Both FWU metadata copies are valid but do not match. Please check!\n");
+		}
+		goto out;
+	}
+
+	ret = -1;
+	if (!(valid_partitions & BOTH_PARTS))
+		goto out;
+
+	invalid_partitions = valid_partitions ^ BOTH_PARTS;
+	ret = gpt_write_mdata_partition(desc,
+					(invalid_partitions == PRIMARY_PART) ?
+					&secondary_mdata : &pri_mdata,
+					(invalid_partitions == PRIMARY_PART) ?
+					primary_mpart : secondary_mpart);
+
+	if (ret < 0)
+		log_debug("Restoring %s FWU metadata partition failed\n",
+			  (invalid_partitions == PRIMARY_PART) ?
+			  "primary" : "secondary");
+
+out:
+	return ret;
+}
+
+static int fwu_gpt_mdata_check(struct udevice *dev)
+{
+	/*
+	 * Check if both the copies of the FWU
+	 * metadata are valid. If one has gone
+	 * bad, restore it from the other good
+	 * copy.
+	 */
+	return gpt_check_mdata_validity(dev);
+}
+
+static int fwu_gpt_get_mdata(struct udevice *dev, struct fwu_mdata *mdata)
+{
+	struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+	return gpt_get_mdata(dev_get_uclass_plat(priv->blk_dev), mdata);
+}
+
+static int fwu_get_mdata_device(struct udevice *dev, struct udevice **mdata_dev)
+{
+	u32 phandle;
+	int ret, size;
+	struct udevice *parent;
+	const fdt32_t *phandle_p = NULL;
+
+	phandle_p = dev_read_prop(dev, "fwu-mdata-store", &size);
+	if (!phandle_p) {
+		log_debug("fwu-mdata-store property not found\n");
+		return -ENOENT;
+	}
+
+	phandle = fdt32_to_cpu(*phandle_p);
+
+	ret = device_get_global_by_ofnode(ofnode_get_by_phandle(phandle),
+					  &parent);
+	if (ret)
+		return ret;
+
+	return blk_get_from_parent(parent, mdata_dev);
+}
+
+static int fwu_mdata_gpt_blk_probe(struct udevice *dev)
+{
+	int ret;
+	struct udevice *mdata_dev = NULL;
+	struct fwu_mdata_gpt_blk_priv *priv = dev_get_priv(dev);
+
+	ret = fwu_get_mdata_device(dev, &mdata_dev);
+	if (ret)
+		return ret;
+
+	priv->blk_dev = mdata_dev;
+
+	return 0;
+}
+
+static const struct fwu_mdata_ops fwu_gpt_blk_ops = {
+	.mdata_check = fwu_gpt_mdata_check,
+	.get_mdata = fwu_gpt_get_mdata,
+	.update_mdata = fwu_gpt_update_mdata,
+};
+
+static const struct udevice_id fwu_mdata_ids[] = {
+	{ .compatible = "u-boot,fwu-mdata-gpt" },
+	{ }
+};
+
+U_BOOT_DRIVER(fwu_mdata_gpt_blk) = {
+	.name		= "fwu-mdata-gpt-blk",
+	.id		= UCLASS_FWU_MDATA,
+	.of_match	= fwu_mdata_ids,
+	.ops		= &fwu_gpt_blk_ops,
+	.probe		= fwu_mdata_gpt_blk_probe,
+	.priv_auto	= sizeof(struct fwu_mdata_gpt_blk_priv),
+};
diff --git a/include/fwu.h b/include/fwu.h
index 2335981d28..ecabf11210 100644
--- a/include/fwu.h
+++ b/include/fwu.h
@@ -14,6 +14,10 @@
 struct fwu_mdata;
 struct udevice;
 
+struct fwu_mdata_gpt_blk_priv {
+	struct udevice *blk_dev;
+};
+
 /**
  * @mdata_check: check the validity of the FWU metadata partitions
  * @get_mdata() - Get a FWU metadata copy
-- 
2.34.1



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